7764 (1890)] decomposes sulphocyanides by fusing with zinc: the zinc is heated with a small quantity of carbon and when completely fused potassium sulphocyanide is added, the mass being well stirred and heated until it thickens and begins to turn red; finally it is allowed to cool out of contact with air, lixiviated with water, the solution decanted, and evaporated to a paste in vacuo.
The potassium sulphocyanide is obtained from ammonium sulphocyanide, which is formed by washing crude coal gas with water containing suspended sulphur.
Ind., 1893, 13, p. 887) digest carbon bisulphide with ammonia and lime in quantities slightly in excess of those demanded by the following equation: 2CS 2 + 2NH 3 + 2Ca(OH) 2 = Ca(SCN) 2 Ca(SH)2+4H20; the product is then treated with a current of carbon dioxide, calcium carbonate being precipitated, sulphuretted hydrogen escaping, and calcium sulphocyanide remaining in solution.
The sulphocyanide is converted into the potassium salt by adding potassium sulphate, and finally desulphurized by lead, zinc, or iron.
When heated with alcohol in sealed tubes, it yields carbamic esters; with alcohol and carbon bisulphide at Ioo° C., carbon dioxide is liberated and ammonium sulphocyanide is formed.