E-2A - Mineral Industry

This sub-category provides methodologies for estimating carbon dioxide ( $CO_{2}$ ) emissions that arise during the processing of carbonate raw materials in the mineral industry. The two primary pathways for $CO_{2}$ release from carbonates are:

Calcination: This involves heating carbonate compounds to release $CO_{2}$ and form metallic oxides. An example is the reaction of calcium carbonate (calcite):

CaCO_{3} + heat ⟶ CaO + CO_{2}

Acid-induced Release: $CO_{2}$ is also released when carbonates react with acids, often as impurities in other processes. For instance, treating phosphate ores with sulphuric acid:

CaCO_{3} + H_{2} SO_{4} ⟶ CaSO_{4} + H_{2} O + CO_{2}

Although the primary focus here is on emissions from calcination, both pathways are considered. Major contributing sectors include:

Additional contributions come from the use of carbonates in other industries like ceramics, soda ash, and non-metallurgical magnesia production.

Carbonates also serve as fluxes and slagging agents in metal smelting and refining (e.g., iron, steel, and base metals like copper) and are used in the chemical industry (e.g., fertiliser).

The methods discussed are designed to attribute $CO_{2}$ emissions accurately to the correct industrial source, ensuring that there is no overlap with energy-related emissions, which are accounted for separately in the Energy Sector.

Emission Estimation Methodologies¶

Tier 1 and Tier 2: Estimate emissions based on the quantity of raw materials or products, using emission factors.
Tier 3: Direct calculations from site-specific data, ensuring all sources of carbonate in raw materials and fuels are included.