IPC 2013 : D21C 3/08 : calcium bisulfite.

IPC2013 > D > D21 > D21C > D21C 3/00 > D21C 3/08[3] > calcium bisulfite.
D SECTION D — TEXTILES; PAPER.
D21 PAPER-MAKING; PRODUCTION OF CELLULOSE.
D21C PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE- CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR.
D21C 3/00 Pulping cellulose-containing materials.
D21C 3/08 · · · calcium bisulfite.