Division 27Production of clinker

### Division 27—Production of clinker 327 (1) The production of clinker is the physical and chemical transformation of: (a) either or both of calcium carbonate compounds (limestone (CaCO3)) and other calcium carbonate (CaCO3) feedstocks; and (b) any of the following: (i) clay; (ii) clay mixed with one or more feedstocks that contain one or more of the following: (A) silicon dioxide (SiO2); (B) iron (Fe); (C) aluminium oxide (alumina (Al2O3)); (iii) one or more feedstocks that, when combined, contain all of the following: (A) silicon dioxide (SiO2); (B) iron (Fe); (C) aluminium oxide (alumina (Al2O3)); that are fused together at a temperature higher than 1 000 °C into Portland cement clinker. (2) The Portland cement clinker must: (a) have a concentration of calcium silicates of at least 60%; and (b) have a concentration of magnesium oxide (MgO) of not more than 4.5%; and (c) be useable in the making of Portland cement. (3) The production of clinker is specified as an emissions‑intensive trade‑exposed activity. (4) The production of clinker is a highly emissions‑intensive activity. > Note: See Part 4. (5) The basis for the issue of free carbon units for the production of clinker is by a tonne of Portland cement clinker on a dry weight basis that: (a) is produced by carrying on the emissions‑intensive trade‑exposed activity; and (b) has a concentration of calcium silicates of at least 60%; and (c) has a concentration of magnesium oxide (MgO) of not more than 4.5%; and (d) is useable in the making of Portland cement; and (e) is of saleable quality. > Note: Saleable quality is explained in Part 2.