Consultation document: code of practice for managing particulate matter emissions in the potash sector

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Mining and processing division
Environment and Climate Change Canada

Proposed – April 2016

Table of contents

Lists of tables and figures

List of tables

List of figures

Abstract

This Code of practice describes operational activities and associated environmental concerns relating to emissons of fine particulate matter (PM2.5) from facilities in the potash sector in Canada. The recommended practices in the Code include the development and implementation of best practices to control and minimize emissions of PM2.5. These recommended practices can be used by the potash industry, regulatory agencies, and the general public as sources of technical and policy guidance. However, these recommended practices do not negate any regulatory requirements.

Executive summary

Federal, provincial and territorial environment ministers are taking action to better protect human health and the environment by endorsing and implementing the new Air Quality Management System (AQMS). The AQMS includes Canadian Ambient Air Quality Standards for fine particulate matter (PM2.5) and ground-level ozone, Base Level Industrial Emissions Requirements (BLIERs) and local Air Zone Management by the provincial/territorial jurisdictions. For the potash sector, a qualitative BLIER (in the form of a Code of Practice) was developed for fine particulate matter with a mean aerodynamic diameter of less than 2.5 microns (PM2.5).

The overall objective of the Code is to identify and promote best practices in the Canadian potash sector with respect to PM2.5 emissions. The Code was developed by Environment and Climate Change Canada in consultation with potash industry representatives and the provinces of Saskatchewan and New Brunswick. Information on best management practices was drawn from various sources such as consulting reports, literature and environmental codes by provinces/territories, Environment and Climate Change Canada and the United States Environmental Protection Agency (U.S. EPA), as well as from individual potash companies and technical journals.

There are currently eleven potash facilities operating in Canada: ten in Saskatchewan and one in New Brunswick. Potash mining in Canada is carried out by means of two distinct methods, conventional underground mining and solution mining. Conventional mining is the process of tunneling below the earth and removing ore deposits from the mine’s walls, and transporting it to the surface for wet processing. Solution mining is an alternative method where unsaturated brine is injected into the underground ore deposit through wells to dissolve potassium chloride (KCl), which is then pumped to the surface for processing. In both cases the ore must be dried, screened, and often compacted to produce marketable products. Nine of Canada’s potash facilities are conventional mines, and two are solution mines.

The major processing activities of the sector, drying and compacting, are the primary sources of PM2.5 emissions. They represent about 80% of sector emissions. The remaining 20% are from the fugitive, loadout, and mine exhaust emissions. Table S-1 lists the 15 recommendations designed to limit PM2.5 emissions from these sources.

The Code describes the sector’s mining and processing activities in Section 2. Section 3 elaborates on the PM2.5 emissions produced by these activities. The recommended work practices intended to control and minimize these emissions are set out in Section 4. Finally, Section 5 outlines a strategy for implementing the code, along with recommendations for reviewing, reporting, and recordkeeping.

This code is designed to be used by the potash industry, or by regulatory agencies and the general public as a source of technical and policy guidance. However, it does not negate any regulatory requirements.

The Code does not require an existing facility to make major technological changes, but rather implement and enhance monitoring and maintenance of its existing abatement equipment. Finally, the recommendations in this Code should be incorporated into the initial design stages of new facilities to control and minimize PM2.5 emissions.

Table S-1: List of recommendations (emission control devices)
Subject Recommendation Sources targeted
Wet Scrubbers R01 - For venturi scrubbers, continuously monitor and record daily average gas flow rate and pressure drop, daily average brine/water flow rate, and daily average fan amperage; calculate liquid-to-gas L/G ratio daily. S5 - Drying
S6 - Screening
S7 - Compacting
S8 - Material Handling
Wet Scrubbers R02 - For non-venturi scrubbers, continuously monitor and record daily average gas flow rate, brine/water flow rate, daily brine nozzle pressure, and daily average fan amperage; calculate L/G ratio daily. S5 - Drying
S6 - Screening
S7 - Compacting
S8 - Material Handling
Wet Scrubbers R03 - Implement maintenance practices specific to wet scrubbers. S5 - Drying
S6 - Screening
S7 - Compacting
S8 - Material Handling
Wet Scrubbers R04 - For all brine scrubber recirculation systems, monitor changes in the brine specific gravity (SG) weekly. S5 - Drying
S6 - Screening
S7 - Compacting
S8 - Material Handling
Baghouses R05 - Continuously monitor the daily average pressure drop and average fan amperage of all baghouses. S6 - Screening
S7 - Compacting
S8 - Material Handling
Baghouses R06 - Install and continuously monitor Baghouse Leak Detection Systems (BLDS) on baghouses. S7 - Compacting
Baghouses R07 - Implement maintenance practices specific to baghouses. S6 - Screening
S7 - Compacting
S8 - Material Handling
Electrostatic Precipitators R08 - Continuously monitor the secondary current and secondary voltage of all electrostatic precipitators. As needed, monitor the spark rate. S5 - Drying
Electrostatic Precipitators R09 - Implement maintenance practices specific to electrostatic precipitators. S5 - Drying

 

Table S-1 (continued): List of recommendations (emission control devices - general)
Subject Recommendation Sources gargeted
General R10 - Implement recordkeeping of monitoring and excursion evaluation for all emission-control devices at significant sources. S5 – Drying
S7 - Compacting
Cyclones R11 - Implement maintenance practices specific to cyclones. S5 - Drying
S6 - Screening
S7 - Compacting
S8 - Material Handling
Table S-1 (continued): List of recommendations (dryers and compactors - maintenance)
Subject Recommendation Sources targeted
Drying R12 - Ensure there are no leaks in the dryer air discharge system that would allow dust to escape. S5 - Drying
Compacting R13 - Ensure that compactor hoods and ducting are fitted properly and have no cracks to prevent dust from escaping. S7 - Compacting

 

Table S-1 (continued): List of recommendations (material handling practices)
Subject Recommendation Sources targeted
Material Storage, Handling, Conveying R14 - Optimize material handling, storage, and conveying practices. S8 - Material handling

 

Table S-1 (continued): List of recommendations (environmental management practices)
Subject Recommendation Sources targeted
Management PracticesFootnote a R15 - Develop and implement broad-based best practices for general environmental management S1 - Subsurface Operations
S2 - Well Drilling
S3 - Dry Crushing
S4 - Evaporation and Crystallization
S5 - Drying
S6 - Screening
S7 - Compacting
S8 - Material Handling

Footnotes

Footnote A

Environmental management practices are referred to in Environment Canada’s Environmental Code of Practice for Metal Mines, 2009. Many of these practices can also be applied to the potash mining industry.

Return to footnote a referrer

1. Introduction

Potash fertilizer production is a major industry in Canada, ranking first worldwide (32% of global production) with an annual capacity of approximately 21.3 million tonnes in 2011. Potash mining in Canada is carried out by means of two distinct methods, conventional underground mining and solution mining. Conventional mining is the process of tunneling below the earth and removing ore deposits from the mine’s walls. Solution mining is an alternative method where unsaturated brine is injected into the ore deposit through wells to dissolve potassium chloride (KCl), and when saturated this brine is pumped to the surface for processing. The major processing activities, drying and compacting, are the primary sources of fine particulate matter (PM2.5) emissions from this sector. Less significant sources include mine air exhaust (from conventional mining only), the use of diesel trucks, crushing, screening, loadout, and fugitive sources.

Federal, provincial and territorial environment ministers are taking action to better protect human health and the environment by endorsing and implementing the new Air Quality Management System (AQMS). The AQMS includes Canadian Ambient Air Quality Standards for fine particulate matter and ground-level ozone, Base Level Industrial Emissions Requirements (BLIERs) and local Air Zone Management by the provincial/territorial jurisdictions

Fine particulate matter with a mean aerodynamic diameter of less than 2.5 microns (PM2.5) is a significant air pollutant in the potash sector. The BLIERs process examined all sources and controls of PM2.5 emissions from potash facilities and concluded that a PM2.5 Emissions Code of Practice (Code) was the most suitable instrument for the control of PM2.5 emissions in this sector.

Annual PM2.5 emissions in the Canadian potash industry have ranged between 785 and 1643 tonnes/year over the 3-year period 2008-2010, and represent 1.8% of total industrial emissions.

1.1 Sector description

Potash is a generic term used to describe a variety of minerals and manufactured chemicals containing potassium, a basic nutrient for plants. Potash ore is comprised of approximately 40% KCl, 55% sodium chloride (NaCl) and 5% insoluble material. It is a limited resource that is found in only a few countries around the world. Canada accounts for almost half of global potash reserves, of which a significant portion is found in the Prairie Evaporite Deposit in Saskatchewan.

In 2013, Canada’s potash industry consisted of three companies with a combined 11 facilities, of which 10 are in Saskatchewan and one in New Brunswick. To date, nine conventional underground mines and two solution mines operate in Canada. These operations are explained in detail in Section 2.

Figure 1-1: Map of Canadian potash facilities

Map of Canadian potash facilities (see long description below).
Description of figure 1-1

The image consists of a black-and-white map of Canada that shows the provincial and territorial boundaries. In the territory representing Saskatchewan, the numbers 1 through 10 are scattered within the provincial boundary representing the 10 potash facilities operating in the province. The name “Saskatchewan” is overlaid on the map above the ten numbers. The number 11 is placed in the boundary representing New Brunswick and it represents the single potash facility in that province. The name “New Brunswick” is overlaid above the number 11. Below the map is the legend which provides a numbered list of Canadian potash facilities that correspond to the numbers located on the map.


On a company basis, in 2011 Potash Corporation of Saskatchewan (PCS) possessed 53% of the potash capacity in Canada, with Mosaic at 39% and Agrium at 8%. All current Canadian potash producers are in the midst of capacity expansions for their operations. There is also significant activity related to potential new producers of potash in Canada.

Canada’s production in 2011 was estimated at 17.2 million tonnes. The majority of Canadian potash is exported, estimated at approximately 98% of production. More than 50% of Canada’s potash exports are shipped to the United States, followed by Brazil, Indonesia, China, and India.

1.2 Objective and scope of the code

The overall objective of the Code is to identify and promote best practices in the Canadian potash industry, in particular with respect to PM2.5 emissions. Adoption of best practices will facilitate continual improvement in environmental performance in the sector. The Code applies to environmental aspects of potash production and to best practices to control PM2.5 emissions, most of which originate from the drying and compacting processes. 

The Code was developed as part of the qualitative BLIERs of Environment and Climate Change Canada’s AQMS policy. The Code does not recommend that existing facilities require major technological changes. However, in the design of new facilites, more current and effective technologies should be considered to further minimize emissions. The Code also recognizes that no one control technology is universally appropriate for every application due to the variability and uniqueness in operating conditions from site to site and between various processes within each site.

The recommendations in this Code should be applied where and when appropriate based on the particular circumstances of each facility. Consequently, the Code does not aim to quantify the effect that each recommendation would have on PM2.5 emissions. Rather, it should be considered a basic tool for developing a program of good practices by the facilities without imposing regulatory constraints. Conversely, the recommendations made herein do not reduce the scope or application of the legal requirements of municipal, provincial, and federal governments.

1.3 Code development

The Code was developed by Environment and Climate Change Canada in consultation with the governments of Saskatchewan and New Brunswick and the potash industry.

Environmental management practices recommended by various national and international organizations were reviewed and incorporated. Information on best management practices was drawn from various sources such as consulting reports, literature and environmental codes by provinces/territories, Environment Canada and the United States Environmental Protection Agency (U.S. EPA), as well as from individual potash companies and technical journals. Three consulting reports in particular, the Hatch foundation reportFootnote 1, the Cheminfo PM reportFootnote 2, and the Province of Saskatchewan’s Potash Mining Supply Chain Requirement GuideFootnote 3 provided the basis of this Code.

A specific approach that was used in the formulation of this Code was developed in the 1990s by the U.S. EPA. It is founded on the principle that emission-control devices that are well monitored and maintained operate at their optimum design efficiencies. This approach is referred to as Compliance Assurance Monitoring (CAM), and provides facility operators with an indication of the most efficient operation of emission control devices. The CAM philosophy establishes enhanced monitoring of significant emission units that use control devices, by:

1.4 Code structure

The Code describes the sector’s mining and processing activities in Section 2. Section 3 discusses the PM2.5 emissions produced by these activities. The recommended work practices intended to control these emissions are set out in Section 4. Finally, Section 5 provides a general approach to the implementation of the Code.

2. Mining and processing activities

This section describes the main functions of each operational activity in the potash sector subject to the Code. It provides a generic description of the two types of mines, and may not depict exactly the activities at all facilities. The nature and scope of the activities covered by the Code are identified, particularly those that may be sources of fine particulate matter emissions (PM2.5), which are characterized in Section 3. Figures 2-1 to 2-3 illustrate the conventional and solution mining and processing activities in this sector.

Figure 2-1: Overview of activities for potash conventional and solution mining

Overview of activities for potash conventional and solution mining (see long description below).
Description of figure 2-1

The image provides a graphical description of the main functions of each operational activity in the potash sector. On the left side of the graphic is the title “Conventional” which has four text boxes stacked underneath the title. These boxes explain the process flow for the conventional mining of potash which starts with “Ore from Underground”, then “Crushing”, “Scrubbing & removal of fine tailings” and “Floatation”.

The right side of the image provides a process flow for solution mining which starts with “Brine from Underground”, “Evaporation” and “Crystallization”. The left and right process graphics converge into a lower center  graphic which explains the common flow of activities for the final processing of the mined potash. It starts with “Debrining/Centrifuging”, then “Drying”, “Screening”, “Compaction/Sizing” and “Material Handling/Loadout”.


2.1 Conventional underground mining

2.1.1 Conventional mining subsurface operations

The typical conventionally mined operation entails two vertical shafts connected by a network of tunnels excavated directly into the seams of potash ore. By means of these tunnels, continuous rotary mining machines extract and deliver the ore to a conveyor belt system which conveys the ore to a system of bins or bunkers for temporary storage. The ore is then removed from the bins, crushed, and loaded into a skip for hoisting. The hoist, conveyor belt, and mining machines are all electrically powered. The service shaft which is used for personnel and equipment also doubles as the fresh air intake for the mine, while the production shaft which is used for hoisting the ore also discharges mine exhaust air. A variety of diesel-powered equipment is used in underground mines, including hauling vehicles, front-end loaders, support and maintenance vehicles, air compressors, and others. In cold weather fresh air intake for the mine is heated by means of natural gas direct-fired mine air heaters.

2.1.2 Conventional mining surface operation

2.1.2.1 Crushing

Prior to entering the mill, the ore is further crushed to achieve liberation of the potassium chloride (KCl). Two different crushing procedures are used - dry and wet crushing. Dry crushing using impactors and vibrating screens is a simpler procedure and causes less corrosion of equipment than in wet crushing; however, the process creates dust, making it difficult to maintain and keep clean. Wet crushing using screens and hydroclones is cleaner because the water adsorbs dust (less dust generated) and allows for more efficient screening. The size of the screen openings depends on the liberation size of the ore. This will vary from site to site because each ore body has somewhat unique mineralogy.

2.1.2.2 Scrubbing and removal of fine tailings

Due to the presence of insolubles such as dolomite, anhydrite, and clay adjacent to the underground seams of potash ore, these insolubles attach themselves to the potash particles as impurities. Scrubbing is the process of adding brine to crushed ore in a series of agitated tank cells to dislodge these impurities from the potash.

Once these impurities are dislodged, they become suspended and must be removed from the solution. Removal of these insoluble minerals is achieved by means of specialized equipment which separates the smaller insoluble particles from the larger sodium chloride (NaCl) and KCl crystals.

2.1.2.3 Flotation

The next step in the process is to separate the potash ore from the NaCl and remaining impurities. This is accomplished by flotation, a process commonly used in mining concentrators for many minerals in the mining industry. Potash ore slurry of 20-40% by weight is prepared in a flotation tank by adding additional brine. Various conditioning agents are added to the slurry, including collector oils, frothing agents, and defoaming agents, which coat the particles of potassium chloride but will not adhere to the particles of sodium chloride. The slurry is agitated and aerated in the flotation tank producing a surface froth containing the bulk of the potash, which is skimmed and transferred to a settling tank. The remaining ore (NaCl, and remaining minor impurities) sinks to the bottom during the aqueous phase and is removed as tailings. Concentrated potash ore is removed from the bottom of multiple flotation cells for further processing, while the frothing mixture is recovered.

2.1.2.4 Heavy media separation

Two operations in Saskatchewan (Esterhazy K1 and K2) produce a specialized potash product referred to as Natural Crystal Granular, an intermediate-sized product (~1.7 mm) which requires the use of heavy media separation to produce it. In this process, the mix of particles containing KCl and NaCl in this size range are introduced into a brine to which magnetite (Fe3O4) was added. The magnetite increases the brine’s specific gravity, which during centrifuging floats the KCl to the surface, while NaCl and other impurities drop out. The KCl is then sent to be debrined.

2.1.2.5 Debrining (centrifuging)

Screen bowl centrifuges are typically used in the potash sector to debrine (remove water or brine from) the flotation concentrates. Brine enters the centrifuge (from the settling tank) at one end and is spun in the centrifuge bowl. The centrifuge forces brine against a screen where product is concentrated. Effluent is forced through the screen into the bowl of the centrifuge (due to centrifugal force). The semi-dried product is passed through the centrifuge along the screen by means of conveyors to the exit where it is taken to have the remaining moisture removed.

2.1.2.6 Drying

The critical thermal process step that removes the remaining moisture from the concentrate following the centrifuging process is referred to as drying. It is essential to have as much water removed as possible to prevent caking during storage. Drying also serves to minimize shipping costs because it removes the added weight of water. Direct-fired rotary and fluidized-bed dryers (both fuelled by natural gas) are typically used to dry the material. The combustion gases remove moisture through direct, turbulent contact with the solids. Dried potash is removed to compactors or storage via a rotary or flap valve, screw conveyor, or chute.

2.1.2.7 Screening

Once potash is dried, it is size classified into products of various size distributions by means of a screening process. Mechanical agitation of a feed mixture forces smaller particles through screens with fixed mesh sizes, while larger particles remain above the screen layer.

2.1.2.8 Compaction

Facilities often have a surplus of fine and standard size fractions following the drying and screening activities. To increase production of larger coarse or granular particles, the compacting process is used. The compactor uses high pressures to compress smaller feed particles into solid flakes, up to 16 mm thick. Not all potash from the drying process is compacted; the amount that feeds the compacting process depends largely on the granular fraction demand. Once compacted, potash flake is impacted to break it apart into large fragments and then screened into granular and coarse product fractions. In a process called glazing, water is added to the sized product to help fuse internal cracks and fissures and then the fractions are re-dried in glazing dryers that are integral with the compacting circuit. Glazing helps to remove sharp edges and to reduce the generation of free fine particulate and dust emissions in handling and shipping the product.

2.1.2.9 General material handling

Material handling operations are typical of any solid fertilizer production operation. Material handling operations generally consist of storage (piles, silos, bins) and transfer operations (conveyor belts, elevators, gravity drop, pneumatic transfer, etc.). Material is also handled by loaders and bulldozers. De-dusting agents are added to minimize emissions at critical stages in material handling. Some product degradation takes place during these operations; therefore certain products are screened at the loading area and dedusted prior to loading.

Figure 2-2: Potash conventional underground mining process flow sheet

Potash conventional underground mining process flow sheet (see long description below).

Yellow balloons indicate main sources of PM2.5, namely drying and compacting.
Grey balloons indicate minor sources of PM2.5

Description of figure 2-2

This figure depicts a process flow sheet for the conventional underground mining and processing of potash. Included in the figure are individual graphics that depict each part of the entire mining and processing operation at a typical conventional potash plant. Each graphic within the figure is unique to a part of the process and has been colour-coded and labeled to describe that part of the process. As well, the figure contains graphics depicting the main and minor sources of PM2.5 emissions from various activities associated with the potash mining and processing process.


2.2 Solution mining

2.2.1 Solution mining subsurface operations

This type of mining starts by the injection of fresh water through two injection wells directly into the underground ore body to dissolve the contained muriate of potash in situ. The impregnated brine is brought to the surface processing plant by the extraction well to remove the dissolved potassium chloride product.

2.2.2 Solution mining surface operations

2.2.2.1 Evaporation

Where evaporation is employed, pumped brine returning from the underground caverns is at 45˚C and is saturated with NaCl and KCl. The next process step takes advantage of the characteristic of KCl whose solubility increases with an increase in brine temperature, and that of NaCl, whose solubility decreases with an increase in brine temperature. The brine is heated to approximately 100˚C, resulting in NaCl precipitating out (due to supersaturation) and the KCl becoming undersaturated. Water is then evaporated from the brine through a series of successive evaporators to raise the concentration of KCL to saturation, force more NaCl to precipitate out, to produce brine mostly saturated with KCl. The resulting brine is pumped to the crystallization circuit.

2.2.2.2 Crystallization

The most common crystallizers used in the potash industry are referred to as proposed tube crystallizers. These crystallizers operate on the principle of gravity settling, and this method is referred to as forced crystallization. Proposed tube crystallizers operate in series of from four to eight units. Each sequential crystallizer operates at a lower temperature and vapour pressure to precipitate out the KCl progressively.

In the wintertime in Saskatchewan, often natural crystallization is implemented by pumping the brine directly to cooling ponds. As the brine cools and the water evaporates due to the large surface area, KCl again precipitates out, and then is dredged from the ponds and processed into potash product.

2.2.2.3 Remaining surface operations

Following this process, the remaining surface operations, namely debrining, drying, screening, and compacting are very similar to those used in conventional underground mining, as described above in section 2.1.2.

Figure 2-3: Potash solution mining process flow sheet

Potash solution mining process flow sheet (see long description below).

Yellow balloons indicate main sources of PM2.5, namely drying and compacting.
Grey balloons indicate minor sources of PM2.5

Description of figure 2-3

This figure depicts the process flow sheet for the solution mining and processing of potash. Included in the figure are individual graphics that depict each part of the entire mining and processing operation at a typical potash solution mining facility. Each graphic within the figure is unique to a part of the process and has been colour-coded and labeled to describe that part of the process. As well, the figure contains graphics depicting the main and minor sources of PM2.5 emissions from various activities associated with the potash mining and processing process.


3. Sources of particulate matter

Sector data indicates that dryers generate roughly half of the sector total particulate matter (TPM) emissions, compactors generate about a third, and remaining sources account for the rest. These estimated emissions categorized by source are shown in Table 3-1.

Table 3-1: Characterization of total particulate matter emissionsFootnote*
Source category Estimated contribution to TPM emissions (%)
Dryers
49%
Compaction
31%
Fugitive
8%
Loadout
7%
Mine exhaust
5%
Total
100%

Footnotes

Footnote *

Source: Hatch Consulting Engineering and Project Implementation. 2008. Environment Canada, Mining and Processing Division Canadian Potash Mining Sector Foundation Report.

Return to footnote*referrer

As can be seen from Table 3-1, the main TPM emission sources are associated with drying and compacting activities. However, some of the lesser emission sources are not insignificant and must be considered as well. Therefore the main focus of this Code will be the optimum operation of the PM2.5 emission abatement equipment, and environmental management practices associated with all identified sources.

The majority of PM2.5 emission sources from potash facilities in Canada are equipped with wet scrubbers for emission abatement. Emissions from wet scrubbers may contain water droplets and these water droplets can interfere with stack testing equipment designed for the measurement of PM2.5. Therefore the available PM2.5 data is not considered as reliable as that for TPM. Nevertheless, an approximate correlation normally exists between TPM and PM2.5 emissions. Accordingly the Code focuses on the major TPM emission sources identified in Table 3-2, and by extension the PM2.5 emissions from these sources should also be reasonably well controlled by the practices recommended by the Code.

The emission sources associated with the mining and processing activities defined in Section 2 are identified and listed in table 3-2 below. The sources which are identified as sources of PM2.5 emissions are designated S1 to S8 for the purposes of identification in Table S-1: List of recommendations, and Section 4: Recommended PM2.5 Emission Control Practices.

Some of the activities described in section 2 are entirely wet processes, and are not sources of PM2.5 emissions. These activities, listed here, are consequently not included in Table 3-2:

Table 3-2: Sources (S) of PM2.5 emissions by activity
Activity PM2.5 emissions

Conventional underground mining

Subsurface operations (S1)

There are some PM2.5 emissions associated with mining underground. These emissions, from operations such as primary crushing, material handling, the use of diesel trucks, and from mine air heating fuel combustion, discharge to atmosphere through the production shaft. However, these emissions are minor compared to the other activities.

Solution mining

Well drilling (S2)

Drilling of wells to develop a series of horizontal subsurface caverns to progressively extract the saturated solution requires drilling equipment. PM2.5 emissions may be associated with diesel engines used to run the drilling equipment. This is a relatively minor source within a facility.

Conventional underground mining

Dry crushing (S3)

Dry crushing generates some PM2.5 emissions, but this a relatively minor source within a facility.
Evaporation and crystallization (S4) Boilers are used to provide steam for these processes. Boiler fuel combustion exhaust contains some PM2.5 but is minor considering the fuel is natural gas.
Drying (S5) Drying generates PM2.5 emissions and these are controlled by dedicated dryer emission control devices, usually wet scrubbers and electrostatic precipitators.
Screening (S6) Screening can generate PM2.5 emissions but these are usually controlled as part of general area ventilation systems.
Compacting (S7) Compacting generates PM2.5 emissions and these are controlled by dedicated compactor emission control devices, usually baghouses.
Material handling (S8) Material handling operations generate PM2.5 emissions but are generally enclosed. Some points have control devices.

4. Recommended PM2.5 emission control practices

This section presents recommended best environmental practices and mitigation measures to control total particular matter (TPM) and PM2.5 emissions from processes in the potash sector. The recommendations in this Code should be applied where and when appropriate based on the particular circumstances of each facility. The recommendations are categorized as follows:

Each recommendation listed in Table S-1 is followed by a brief discussion of the sources of particulate matter listed in the table.

4.1 Emission control devices

Emission control devices are defined as equipment, other than inherent process equipment, that is used to destroy or remove air pollutants from emission prior to the discharge to the atmosphere. Control devices that are typically used in the potash industry include wet scrubbers, baghouses (fabric filters), and electrostatic precipitators (ESPs). Since cyclones can be used to separate coarse particulate from the exhaust stream, they are often installed as a control device in series with one of the other devices, namely a scrubber, baghouse, or an ESP.

4.1.1 Wet scrubbers

Wet scrubbers are classified as a wet particulate removal system. They remove particulates from an air stream by having them impinge on water droplets, or by becoming absorbed by the water. The water containing the particulate matter is then removed from the collector as a waste stream.

There are several types of wet scrubbers available using different operating principles; four of the more common types are described below:

Recommendation R01 – For venturi scrubbers, continuously monitor and record daily average gas flow rate and pressure drop, daily average brine/water flow rate, and daily average fan amperage; calculate liquid-to-gas (L/G) ratio daily.

Recommendation R02 – For non-venturi scrubbers, continuously monitor and record daily average gas flow rate, brine/water flow rate, daily brine nozzle pressure, and daily average fan amperage; calculate L/G ratio daily.

Sources targeted – S5, S6, S7, S8

As outlined in the Compliance Assurance Monitoring (CAM) provisions, first establish the normal operating ranges of these devices during initial equipment  installation and commissioning, periodic stack testing, performance testing, and/or periodic calibration as specified by the manufacturer.

Pressure drop and liquid flow rate are often required to be monitored continuously for wet scrubbers. Any situation that increases the resistance to air movement through a device will increase the pressure drop and any situation that decreases the resistance to air movement will decrease the pressure drop.

The flow rate of liquid (i.e., water or brine) to the wet scrubber is another simple operating parameter that can be monitored to ensure proper operation of the control device. An increased liquid flow rate may increase the size of droplets beyond the optimum size required to collect dust particles. It may also indicate the risk of erosion of the nozzle orifice. A decreased liquid flow rate may indicate a sub-optimum liquid contact, or sub-optimum droplet size. It may also indicate the risk of solids deposition or plugging in the liquid supply header or nozzles. Key attention should be paid to the nozzles and the water flow. Nozzles are typically set up for easy maintenance and they should be regularly checked because any plugging in the nozzles affects performance.

Measuring liquid flow rate is also required as it is directly related to the liquid-to-gas (L/G) ratio. Since the exhaust gas flow rate is typically a constant value set by the fan speed on the ventilation system, the liquid flow rate is the simplest parameter to monitor to ensure that the optimum L/G ratio is being achieved. For dynamic ventilation systems, where exhaust gas flow may change significantly, the monitoring of liquid flow rate alone is insufficient so monitoring of exhaust gas flow is also required to ensure that the ventilation system is achieving the optimum L/G ratio.

The fan current (fan amperage) should be monitored since it is proportional to power draw. In case the fan amperage decreases, it implies a pluggage and in case the fan amperage increases, it indicates that there is cold air going through the system. If a wet fan is involved, the total fan power is a function of how much water is being applied to the fan and the specific gravity (SG) of the brine.

Recommendation R03 – Implement maintenance practices specific to wet scrubbers.

Sources targeted – S5, S6, S7, S8

To ensure that the scrubbers are operated at their optimum design conditions, create and implement a maintenance program and schedule specific to the equipment based on manufacturing recommendations and site-specific requirements. The program may include:

Recommendation R04 – For wet scrubber recirculation systems, monitor and record changes in the brine specific gravity (SG) weekly.

Sources targeted – S5, S6, S7, S8

Establish the normal operating range in brine specific gravity for the scrubber recirculation system.

Critical instrumentation to consider would be a SG monitor, which would indicate that the scrubber is maintaining a brine flow at the desired level. Changes in the SG indicate increasing concentration is occurring, which is an indicator of brine flow failure. A higher SG provides an early indication of reduced water flow and potential for plugging. It may also indicate potential reduced cyclone collection efficiency upstream (see 4.2.1).

4.1.2 Baghouses

A baghouse is a large filter housing filled with numerous long filter bags. Typically, the bags are cylindrical and made of fabric, although a flat bag or a pleated filter can also be used, and ceramic and sintered metal bags are available. In operation, dust-laden gases enter the chamber and pass through fabric bags that act as filter. A cake of solids is built up on the fabric surface, and it is this porous cake that conducts the particulate filtering. If the cake does not build up, the fine particulate present in the flue gas would penetrate into the fabric pores and quickly plug or blind the filter bag. With the cake, the blinding process is substantially slowed, and the bags may last from weeks to years, depending on the bag and particulate characteristics. The bags are usually cleaned by a reverse air, mechanical shaking, or a pulse jet. The pressure drop for a baghouse can range from 1 to 2.5 kPa (4 to 10 inches of water).

Recommendation R05 – Continuously monitor the daily average pressure drop and average fan amperage of all baghouses.

Sources targeted – S6, S7, S8

Establish and record the baseline pressure drop of the baghouse being monitored on initial equipment installation and commissioning, periodic stack testing, performance testing, and/or periodic calibration as specified by the manufacturer.

The static pressure drop establishes an indicator of the resistance provided by the fabric cloth and its collected layer of dust. It is also directly proportional to the exhaust gas volumetric flow rate. The ongoing operational pressure drop for each baghouse can be compared against baseline values (normally established during performance testing) to ensure proper baghouse operation. An increased static pressure drop generally indicates high gas flow rates, fabric blinding, or system cleaning problems.Footnote5Conversely, a decreased static pressure drop is generally caused by reduced gas flow rates, excessive cleaning intensities or frequencies, reduced inlet PM loading, or possibly bag leakage.Footnote6

The continuous measurement of fan motor current through an ammeter is a method of determining the load that the fan must overcome to push (or pull) the exhaust gas through the fabric filter. This is an indicator of the resistance offered by the filters and the built-up dust. While increases in fan amperage generally indicate high exhaust gas flow, excessive cleaning, or possibly bag leakage, decreases in fan amperage generally imply reduced gas flow rates, or a higher degree of dust build-up.

Recommendation R06 – Install and continuously monitor Baghouse Leak Detection Systems (BLDS) voltage on baghouses.

Source targeted – S7

Leaking or broken filters can lead to safety risks, reduced process efficiency, housekeeping and maintenance issues, damaged ventilation equipment, and environmental compliance violations. A recent compliance trend in the U.S. is to require baghouses to have a BLDS installed in the clean-air exhaust gas outlet to monitor significant changes in dust levels. The BLDS operates based on the triboelectric effect (also known as particle impingement or frictional electrification), which is the electrical charge transfer that occurs between two materials when one rubs or is impacted against the other. In operation, dust particles flowing in the air stream in the duct collide with the probe, generating an electrical charge. The electronics converts this charge to a particle emission signal voltage and continuously monitors and analyzes the signal during the baghouse operation. When the signal exceeds a pre-set PM level for a specified time delay, an alarm notifies the operators that a filter bag is leaking or has failed.Footnote7

Recommendation R07 – Implement maintenance practices specific to baghouses.

Sources targeted – S6, S7, S8

Baghouses should be subject to a prescribed operations/maintenance routine that includes several components at prescribed frequencies: inspection and maintenance of hopper dust removal, compressed air supply and distribution, proper operation of cleaning cycles, functioning of bag cleaning mechanisms, bag integrity, and physical integrity of baghouse. Furthermore, inspection of baghouses is critical in maintaining reliable long-term operation. There are several areas that require attention through routine inspection, including:

4.1.3 Electrostatic precipitators

Particulate removal in an electrostatic precipitator (ESP) involves the discharge electrodes and the collection electrodes. In the first step, particulate is given an electrical charge by means of a high voltage (up to 100 000 V) applied to the discharge electrodes. The particulate is then attracted to and precipitates on the collection electrodes by virtue of their opposite charge. For proper precipitation to occur, the drag force on the particles from the gas flow must be lower than the electrostatic force, and the residence time in the ESP must be sufficient for the particles to reach the collection electrodes. Gas velocity in an ESP typically ranges from 0.6 to 1.5 m/s, and gas residence time can be as high as 15 sec.

Recommendation R08 – Continuously monitor the secondary current and secondary voltage of all electrostatic precipitators. As needed, monitor the spark rate.

Source targeted – S5

Establish the baseline voltages and spark rates on initial equipment installation and commissioning, performance testing, and/or periodic calibration as specified by the manufacturer.

The secondary voltage provides an indication of the strength of the electrical field surrounding the discharge electrodes, which is related to the attraction force exerted on the particles in the exhaust gas. The secondary current is a measure of the quantity of dust that is diverted from its flow path to contact and adhere to the discharge electrode. This parameter is related to the overall dust load being captured by the ESP’s discharge electrode. These two parameters should be monitored continuously for dry ESPs under the Compliance Assurance Monitoring provisions in the United States Environmental Protection Agency (U.S. EPA) Maximum Achievable Control Technology (MACT) standards. Also, spark rate is a measure of how close to the maximum voltage at which an ESP is operating and provides an indicator of collection efficiency.Footnote8

The ESP’s performance can be evaluated by comparing the secondary currents, secondary voltages, and spark rates against baseline values. If the unit does not have secondary voltage meters, similar analyses can be conducted using the primary currents, primary voltages, secondary currents, and spark rates. Having a large spacing between discharge and collecting electrodes allows higher electric fields to be used, which tends to improve dust collection. To generate larger electric fields, however, power supplies must produce higher operating voltages.Footnote9

Recommendation R09 – Implement facility maintenance practices related to electrostatic precipitators.

Source targeted – S5

To ensure that ESPs are operated at their optimum design conditions, the following checklists can be applied:

4.2 Emission control devices - general

Recommendation R10 – Implement recordkeeping of monitoring, excursion evaluation and excursion correction of all emission control devices at significant sources.

Sources targeted – S5, S7

Ongoing recordkeeping is important to determine the effectiveness of the Code, and to identify opportunities for improvement.

When an excursion occurs, it is good practice to monitor the control device performance hourly in the period after the excursion. It is also recommended to evaluate and correct the problems that have affected the control equipment in a formal manner. A quality improvement plan (QIP) is a formalized written plan that outlines the procedures used to evaluate problems that affect the performance of control equipment, and has two basic components:Footnote10

4.2.1 Cyclones

Cyclones separate solids from gas streams by centrifugal force. Cyclone separators are vertical, cylindrical vessels with a gas entrance designed to give a spiralling gas flow around and down the cyclone wall. Once the gas is in the cyclone, the downward spiralling flow of the gas stream imparts a centrifugal force on the particulate, which is thrown radically outward to the cyclone wall. When the particles hit the wall, much of their momentum is absorbed, and they fall to a cone-shaped section at the bottom of the cyclone. The particles are discharged out of the cone through a narrow neck, while the gas continues spinning along the wall inside the cylindrical vessel and exiting through a tube that is mounted in the center of the top of the cyclone.Footnote11

Recommendation R11 – Implement maintenance practices specifically related to cyclones.

Sources targeted – S5, S6, S7, S8

The particle collection efficiency of cyclones depends on a number of factors, including the dimensions (length and diameter) of the cyclone, the inlet gas velocity, the particle size, and the dust concentration in the gas stream. Collection efficiency often rises when inlet gas velocity increases and when particle size and dust concentration increases. Also, smaller cyclones are usually more efficient than larger cyclones. The physical condition of the cyclone body also affects removal efficiency. Dents, riveted joints, and other surface irregularities can disrupt the vortex within the cyclone, thereby causing particles to bounce back into the centre of the cyclone instead of being concentrated near the cyclone wall. Air infiltration through the solids discharge valve, holes, or weld failures can also disrupt the vortex.Footnote12

Cyclones are the simplest piece of equipment among the PM removal systems, but the following checklist can be applied to ensure that they are operated at their optimum conditions:

4.3 Dryers and compactors

Recommendation R12 – Ensure there are no leaks in the dryer air discharge system that would allow dust to escape.

Source targeted – S5

As part of normal operations, regularly inspect the drying equipment, including sealing joints and other sections of the air ducting to prevent dust from escaping. Initiate corrective actions accordingly.

Recommendation R13 – Ensure that compactor hoods and ducting are fitted properly and have no cracks to prevent dust from escaping.

Source targeted – S7

As part of normal operations, regularly inspect the compacting equipment, including sealing joints and other sections of the air ducting to prevent dust from escaping. Initiate corrective actions accordingly.

4.4 Material handling practices

Material handling operations are commonly found in any solid fertilizer production operation, and these operations generally consist of storage (piles, silos, bins) and the transfer operations (conveyor belts, elevators, gravity drop, pneumatic transfer, etc.). Material handling operations generate PM2.5 emissions but are usually enclosed, and some points have control devices.

Recommendation R14 – Optimize material handling, storage, and conveying practices.

Source targeted – S8

Particulate matter emission controls for material handling involves physical practices. Weather monitoring and suspension of operations during severe/adverse weather conditions (mainly high wind speeds) can decrease particulate emissions. Point sources in the materials handling processes can be altered to reduce particulate emissions. More specifically, conveyors can be altered in the following ways:

Loading, unloading and transfer points can be optimized to minimize emissions by reducing drop heights. Minimizing drop heights and regular cleanings of front-end loaders would also reduce emissions.

4.5 Environmental management practices

Recommendation R15 – Implement broad-based best practices for general environmental management.

Sources targeted – S1 through S8

There are a number of reference materials that speak to good environmental practice, such as:

5. Implementation of the code of practice

Implementing the Code should result in controlling and minimizing particulate matter and PM2.5 emissions for the facilities concerned. Successfully achieving this includes an implementation plan and self-monitoring by the facilities. This section outlines an approach to developing individual work methods, applying them and following up on them on a regular basis to improve or maintain performance (Figure 5-1). The facility concerned could take a different approach depending on its needs and structure.

Figure 5-1: General approach to implementing best practices by a potash facility subject to the code of practice

General approach to implementing best practices by a potash facility subject to the vode of practice (see long description below).
Description of figure 5-1

This figure is a block diagram (a series of boxes connected by arrows) which is separated onto two groupings (planning and application) and depicts an approach to developing individual work methods, applying them and following up on them on a regular basis to improve or maintain performance.

In the upper grouping entitled planning, there are 5 coloured boxes that highlight components of the planning stage. The first box is split in two parts. The first part is “analyze methods currently used to monitor PM2.5 emission abatement equipment”, the second is “establish baseline operating ranges of PM2.5 monitoring devices”. Once a facility has analyzed its PM2.5 monitoring methods they should proceed to the next step, contained in the box directly to the right, which is to “develop improved procedures based on the code of practice and current work methods”. The next step, listed in the box directly below, is to “prepare training plan for affected employees”.

Following the establishment of baseline operating ranges listed in the second box, the next step, on the left hand side of the figure directly below the first two boxes, is to “develop protocol for auditing the effectiveness of improved monitoring of PM2.5 emission abatement equipment”.

In the lower grouping entitled application, there are 4 coloured boxes in a closed-loop configuration that highlight components of the application stage of the recommendation contained in the code. The box on the far right of the figure suggests that the facility “inform affected employees of improved monitoring procedures based on training plan”. Following this step the box at the bottom of the grouping states “implementation of improved monitoring procedures by employees”. The box on the left hand side, is split into two parts. The first part is “audit the effectiveness of improved monitoring” and the second is “developing corrective measures as needed”.


5.1 Initial planning

It is advisable to analyze the current situation in the plant to carry out individual procedures based on the recommendations of the Code. After the new practices are implemented, it is important to ensure that they are effective and are yielding the expected results. Such analysis should follow a predetermined protocol for auditing on-site activities relating to the new practices.

5.1.1 Analysis of current situation

The purpose of the initial analysis is to obtain not only relevant information and data on the technologies in place, but especially the operating, control and maintenance methods of the plant in question. A questionnaire or checklist would be an appropriate tool for this task.

5.1.2 Development of custom procedures

Based on the results of the initial analysis, opportunities for improvement in the monitoring of PM2.5 emissions abatement equipment could be identified. The facility could thus develop their own procedures (in a custom document) on the basis of recommendations provided in the Code and the plant’s unique characteristics. The development of custom procedures may mean adopting practices that are not mentioned in the Code but would nonetheless control PM2.5 emissions, according to the facility’s analysis. The Code is not restrictive in this regard.

Consultation with employees should facilitate the implementation of the new procedures at the appropriate time and prevent problems that might arise if employees are not consulted.

5.1.3 Employee training plan

From a strategic standpoint, it is advisable to prepare a training plan for employees required to modify or implement new procedures. Successful training depends on properly prepared documents and training as well as on the standardization of the new procedures.

5.1.4 Protocol for reviewing the effectiveness of custom procedures

New or modified procedures should be monitored regularly to ensure they are yielding the desired results. A review should preferably be carried out using a protocol developed alongside the procedures. The best approach is to prepare a checklist with qualitative and quantitative questions to assess the current situation properly. Where applicable, this checklist should contain the baseline ranges established following the initial analysis. This protocol should also provide for a consistent review methodology.

Annex A offers a Recordkeeping Template that facilities may choose to use for this purpose.

Baseline operating ranges of monitoring and control devices are typically established during initial equipment installation and commissioning, periodic stack testing, performance testing, and/or periodic calibration as specified by the manufacturer.

5.2 Implementation of the code

It is to be expected that the results of new procedures will not be optimal at the beginning and that corrections will probably have to be made after the initial review. This review–correction cycle should be applied periodically even when the level of monitoring is deemed satisfactory by the facility.

5.2.1 Performance Review of Improved Procedures

It is recommended that a review of the new procedures be carried out quite frequently at the beginning (e.g., 6–12 months) according to the protocol developed for that purpose (Section 5.1.4) to fine-tune the procedures. When all the procedures are diligently followed by the staff concerned, reviews could be undertaken less frequently. They will nonetheless have to be maintained at a reasonable frequency for quality control purposes.

Each potash facility using the Code should retain, for a reasonable period of time, all this recorded information which will demonstrate that the objectives of this Code are being met. This log will help determine the overall effectiveness of the Code and will identify future opportunities for improvement.

5.2.2 Reporting

To assess the degree of implementation of this Code and to monitor levels of PM2.5 emissions, potash facilities will submit the following to Environment and Climate Change Canada:

Reports are to be provided to Environmentand Climate Change Canada on or before June 1 of the year following the reporting year (Jan 1 to Dec 31)

A sample of the information that would be included in the report is provided in Annex B.

Facilities should use standard methods to quantify PM2.5 emissions, such as:

Nomenclature

Abbreviations

AQMS
Air Quality Management System

BLDS
Baghouse Leak Detection Systems

BLIERs
Base-level Industrial Emissions Requirements

CAM
Compliance Assurance Monitoring

CCME
Canadian Council of Ministers of the Environment

ESP
Electrostatic Precipitator

Fe3O4
Iron (II, III) Oxide (magnetite)

MACT
Maximum Achievable Control Technology

KCl
Potassium Chloride (muriate of potash or sylvite)

NaCl
Sodium Chloride (halite)

PCS
Potash Corporation of Saskatchewan

PM10
Particulate Matter (under 10 microns)

PM2.5
Fine Particulate Matter (under 2.5 microns)

QIP
Quality Improvement Plan

SG
Specific Gravity

SO2
Sulphur Dioxide

TPM
Total Particulate Matter

U.S. EPA
United States Environmental Protection Agency

Glossary

Baghouse (fabric collector)
Type of dust collector that uses large filter housing filled with numerous long filter bags to capture particles contained in gas.

BLDS
Baghouse Leak Detection System: A stainless steel probe inserted into the middle of the clean air duct of a baghouse and a linkage to the sensing electronics to detect leaking or broken filters.

Brine
Brine is a solution of salt, usually sodium chloride, in water.

Centrifuging (debrining)
Screen-bowl centrifuges are used to remove water (debrine) from the flotation concentrates.

Compacting
Process used to produce larger, coarse and granular particule sizes in the potash sector.

Conventional underground mining
The process of tunneling below the earth and removing ore deposits from the subsurface.

Crushing
Process used in underground mining that reduces the particle size distribution of large mineral ore pieces to finer pieces.

Crystallization
Process used to produce soluble grade muriate of potash, which separates minor impurities of sodium chloride from potash fines of greater purity.

Cyclones
PM control devices used to separate solids from gas streams by centrifugal force, which are suitable for high dust loadings and removal of coarse particulate fractions.

Drying
Thermal process that removes the remaining moisture content and burns residual organic reagents (especially flotation amine) from the centrifuging process.

Dust collector
Processing unit designed to capture most particles contained in gas.

Electrostatic precipitator (ESP)
A large chamber filled with long, vertical electrodes that uses magnetic forces to separate suspended particulate matter from the gas stream.

Excursion
A deviation of one or more operating, maintenance or other parameters that materially reduce the PM reduction efficiency of the control equipment below its best possible or design control efficiency.

Evaporation
Solution mining process used prior to crystallization where the brine is heated up to approximately 100 0C, making it undersaturated in KCl and supersaturated in NaCl, to precipitate out the NaCl.

Froth flotation
Process used to achieve primary separation of potash ore (KCl) from halite (NaCl) and gangue materials. Chemicals, amine renders KCl hydrophobic (attach to air bubbles) while leaving NaCl hydrophilic.

Glazing
Post-treatment step where the final products are mixed with a small amount of water and dried again to obtain a hard outer coating, to fill cracks in the particles, to strengthen the compacted particules, and to eliminate sharp corners.

Heavy media separation
Process to produce an intermediate-sized product (~1.7 mm) at two specific facilities. In this process, a mix of particles containing KCl and NaCl in this size range are introduced into a brine to which magnetite (Fe3O4) was added. The magnetite increases the brine’s specific gravity, which during centrifuging floats the KCl to the surface, while NaCl and other impurities drop out. The KCl is then sent to be debrined.

Liquid-to-gas (L/G) ratio
Measure of water (or brine) flow rate through the scrubber per unit volume of exhaust gas; indicates scrubber collection efficiency.

Prairie evaporite deposit
An area beneath the southern plains of Saskatchewan where a significant portion of the potash reserves is located.

Removal of fine tailings
Process of removing insoluble minerals (fine tailings) that are part of the brine used in scrubbing.

Screening
Mechanical process of sizing dried potash into classified fractions.

Scrubbing
Process of adding brine to crushed ore in agitaded tank cells to remove clay and other insoluble impurities.

Spark rate
A measure of how close to the maximum voltage an ESP is operating; provides an indicator of collection efficiency.

Venturi wet scrubber
High-velocity and high static pressure drop gas cleaning system that atomizes water/brine to achieve high collection efficiencies.

Wet scrubber
Wet particulate removal system where the polluted gas stream is brought into contact with the scrubbing liquid to remove air pollutants.

References

Cheminfo Services Inc. 2013. Particulate Matter Emissions in the Canadian Potash Sector. Final Report.

Hatch , Consulting Engineering and Project Implementation. 2008. Potash Environment Canada, Mining and Processing Division Canadian Potash Mining Sector Foundation Report. Potash Foundation Final Report.

AMEC Engineering & Construction Services Limited (1990) Potash Processing in Saskatchewan – A Review of Process Technologies

ASTM D-6216-07 (2007) Standard Practice for Opacity Monitor Manufacturers to Certify Conformance with Design and Performance Specifications

Biotechnology and Environmental Engineering R & D Ltd (2004) 3.3 Potash: 3.3.1 Mineralogy and Mining Techniques.

Bonine, S. and Otte, C., Monitor Technologies LLC, (2010) How to detect leaking or broken filters with a triboelectric monitor”, Powder and Bulk Engineering

CED Engineering (1998) Baghouses and Filters for Particulate Matter Control

Cheminfo Services Inc. (2009) Technical Evaluation of Options for Air Pollution Control of Emissions from the Integrated Iron & Steel and Non-Integrated Steel Sub-sectors, Part One – VOC and PM, Final Report.

Chevron Phillips Chemical Company LLC (2012) Introduction to Mineral Processing: Froth Flotation

Energy Information Administration (1994) Longwall Mining

Environment Canada, (1993) Standard Reference Methods for Source Testing: Measurement of Emissions of Particulate from Stationary Sources, Reference Method EPS 1/RM/8.

GEA Barr-Rosin (2012) Solids Drying

GEA Process Engineering Inc. (2012) Fluid Bed Drying – Fundamentals

Marama, PM CEMS Webinar (Oct. 6, 2011) TEOM Technology

Midwest Research Institute (2000) Current Knowledge of Particulate Matter (PM) Continuous Emission Monitoring, United States (US) Environmental Protection Agency, Office of Air Quality Planning and Standards, Emission Monitoring and Analysis Division, Research Triangle Park, EPA-454/R-00-039

Natural Resources Canada (2009) Canadian Minerals Yearbook: Potash

Partha Das Sharma (2008) Sublevel Caving Technique

United States Environmental Protection Agency (U.S. EPA), Air Pollution Control Cost Manual, Sixth Edition (EPA/452/B-02-001), 2002, Section 6 Particulate Matter Controls.

U.S. EPA, Air Pollution Training Institute (APTI), SI:445 - Introduction to Baseline Source Inspection Techniques, Lesson 12 - Level 2 Inspections.

U.S. EPA, Air Pollution Training Institute (APTI), SI:445 - Introduction to Baseline Source Inspection Techniques, Lesson 10 - Operation of Electrostatic Precipitators

U.S. EPA, Air Pollution Training Institute (APTI), SI:445 - Introduction to Baseline Source Inspection Techniques, Lesson 17 - Operation of Mechanical Collectors

U.S. EPA, Air Pollution Training Institute (APTI), SI:445 - Introduction to Baseline Source Inspection Techniques, Lesson 12 - Level 1 Inspections

U.S. EPA, Air Pollution Training Institute (APTI), SI:445 - Introduction to Baseline Source Inspection Techniques, Lesson 10 - Operation of Electrostatic Precipitators

U.S. EPA, CEMS Performance Specification 1 for Opacity

U.S. EPA (2003) National Emission Standards for Hazardous Air Pollutants: Taconite Iron Ore Processing; Final Rule (40 CFR Part 63 RRRRR), Oct 29, 2003.

U.S. EPA, (August 1998) Technical Guidance Document: Compliance Assurance Monitoring (CAM), Revised Draft

U.S. EPA, Test Method 201A: Determination of PM10 and PM2.5 Emissions from Stationary Sources (Constant Sampling Rate Procedure)

U.S. EPA, Test Method 5: Determination of Particulate Matter Emissions from Stationary Sources

Washington State University (1994) Potash Crystallization

Environment Canada. 2009. Environmental Code of Practice for Metal Mines. Mining and Processing Division. 1st Edition, 2009.

Environment Canada, Environmental Code of Practice for Base Metals Smelters and Refineries – CEPA 1999 Code of Practice, March 2006.

Environment Canada, Environmental Code of Practice for Integrated Steel Mills – CEPA 1999 Code of Practice, 1st Edition, March 2001.

Environment Canada, Environmental Code of Practice for Non-Integrated Steel Mills – CEPA 1999 Code of Practice, 1st Edition, March 2001.

Environment Canada, National Pollutant Release Inventory (NPRI).

Ministry of the Economy. 2012. Potash Mining Suppy Chain Requirement Guide. Greenfield Mine Lifecycle Costs. Hatch Limited.

Perucca, C.F. 2001. Potash Processing in Saskatchewan. A Review of Process Technologies.

Klein, O.M., and Reid, K.W., Goldsmith, E.L. 1994. Pollution Control in Fertilizer Production. Edited by C.A. Hodge & N.N. Popovich. Chapter 27, Air Emissions at Potassium Chloride (KCl) Facilities.

Annexes

Annex A: Recordkeeping template (refer to section 5.1.4)

Facilities may choose to use this template to assess initial conditions and for review purposes. The table lists the Code’s recommendations with associated parameters.

Facility

Contact information

Table 1. Code recommendations with associated parameters
Recommendation
Parameters
Monitoring frequency
Normal operating range
Daily value recorded
(unless otherwise specified)
Date
Indicate whether reading is within range
Yes
Indicate whether reading is within range
No
R01 - venturi scrubbers gas flow rate continuous          
R01 - venturi scrubbers gas pressure drop continuous          
R01 - venturi scrubbers water/brine flow rate continuous          
R01 - venturi scrubbers fan amperage continuous          
R01 - venturi scrubbers L/G ratio calculate daily          
R02 - non-venturi scrubbers gas flow rate continuous          
R02 - non-venturi scrubbers water/brine flow rate continuous          
R02 - non-venturi scrubbers nozzle pressure continuous consult manuf consult manuf      
R02 - non-venturi scrubbers fan amperage continuous          
R02 - non-venturi scrubbers L/G ratio calculate daily          
R04 - brine recirculating systems brine specific gravity weekly          
R05 - baghouses gas pressure drop continuous          
R05 - baghouses fan amperage Continuous          
R06 - baghouses BLDS voltage Continuous          
R08 - ESPs secondary current Continuous          
R08 - ESPs secondary voltage Continuous          
R08 - ESPs spark rate Weekly consult manuf consult manuf      

R10 Excursions - emission control device

Excursion noted on device
Specify device and excursion Date
   
   
   
   

 

Excursion correction
Type of correction implemented Date
   
   
   
   

 

Maintenance practices Status of system or device Follow-up actions if required Date
R03 - wet scrubbers      

system leaks

     

corrosion

     

pump, piping, pressure gauges

     
R07 - baghouses      

pressure taps

     

triboelectric probe

     

fans

     

bag cleaning mechanism

     

bags

     
R9 - ESPs      

power consumption

     

dust concentration at exit

     

plates/tubes/wires

     
R11 - cyclones      

dust collection at exit

     

corrosion, plugging

     

cyclone design

     

air lock

     
R12 - general facility      

dryer air discharge system

     
R13 - general facility      

compactor hoods and ducting

     
R14- general facility      

materials handling processes

     

 

R15 Environmental management practices - general facility Status of implementation Date
Environmental management practices - list    
 

Annex B: Sample report template

Part A: Emissions reporting

Facilities are asked to report their PM2.5 emissions as well as the measurement method used to quantify those emissions in a table similar to the format provided below.

Annual reporting of PM2.5 emissions
Source of PM2.5 Annual quantity of PM2.5 emitted (tonnes) Quantification methodology
Stack/Dryers    
Stack/Compactors    
Storage or handling    
Fugitive    
Other non-point    
Road dust    
Total quantitiy emitted (t)    

Part B: Reporting on the implementation of the code of practice

The following provides a list of sample questions which may be used to demonstrate facility progress towards implementation of the Code.  For each recommendation in this Code, facilities are asked to provide answers to the following questions:

Facilities should provide, if needed, any additional information on each recommendation.

Part C: Declaration

A declaration, as per the example below, is to be attached to each report.

I declare that this report is true, accurate and complete.

 

_________________________________
Operator’s name (please print)

_________________________________
Position title

 

_________________________________
Telephone

_________________________________
Email

 

_________________________________
Operator’s signature

_________________________________
Date of signature

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