Improvements in or relating to a process for preparing pure potassium nitrate commercially free from chlorides and sodium salts

摘要

Materials containing potassium acid tartrate are finely ground and dried and treated in hot condition in aqueous suspension, first with calcium carbonate or calcium hydroxide, and then with calcium nitrate, in order to precipitate calcium tartrate from which tartaric acid is obtained and potassium nitrate. The calcium tartrate is filtered off, washed and converted to tartaric acid by the usual methods.ALSO:Potassium nitrate, free from chlorides and sodium salts is prepared by treating raw materials containing potassium acid tartrate, finely ground and dried, in aqueous suspension, first with calcium carbonate or calcium hydroxide and then with calcium nitrate. Calcium tartrate is precipitated and potassium nitrate is left in solution from which it is separated.