Response to comments on draft code of practice to reduce emissions of particulate matter: primary aluminium sector

On June 16th, 2014, Environment Canada published a draft Code of practice to reduce emissions of fine particulate matter (PM_2.5) from the aluminum sector. The publication of the draft code was followed by a 60-day comment period which ended on August 15th, 2014.

The code describes operational activities and associated concerns of fine particulate matter (PM_2.5) for the primary aluminum sector including: aluminum production with prebaked anode technology; prebaked anode production; green coke calcining and alumina production. It presents recommendations for the implementation of best practices to reduce emissions of PM_2.5. These recommended practices can be used by the aluminum industry, regulatory agencies and the general public as sources of technical and policy guidance but do not negate any regulatory requirements.

During the comment period, written comments on the draft code were received from a variety of stakeholders including members of the industry and academic researchers. Additional comments were received after the initial comment period and during subsequent consultations with stakeholders. All comments have been considered in finalizing the code.

Key changes to the draft code

Environment Canada has accepted the majority of the comments received resulting in a number of modifications reflected in the final code:

• For clarity and ease of use, two sections in the draft code, “Operational activities” and “Sources of particulate matter”, were merged into one section called “Operational activities and sources of particulate matter”.
• For consistency and coherence throughout the code, the section “Recommendations for PM_2.5 emission control practices” was reorganized according to the four operational activities related to the primary aluminium sector:
  • Aluminium production (electrolytic reduction);
  • Prebaked anode production;
  • Green coke calcination; and
  • Alumina production.
• For clarity, the alpha-numeric codes used to identify each recommendation have been replaced by new codes (that is, R01 to R44).
• A number of comments provided greater clarity or more precise technical terminology, for example, “NaF is never added to the bath, but rather Na₂CO₃ (soda ash)”. These technical changes were incorporated where appropriate.
• None of the original recommendations in the draft code were removed. Based on the comments received, some recommendations were modified for greater technical precision, for example, D06 (now R38): “baghouse” was revised to “dust collector”. Other recommendations were modified to accommodate the specific needs of each facility, e.g. “daily” frequency was revised to “regularly and periodically”.
• Section 5 (Implementation of the code of practice) has been removed and replaced by a new recommendation (R44).  This provides greater flexibility for facilities on how to implement the draft code to achieve best environmental practices to reduce emissions of PM_2.5.