METHOD FOR DEMERCURATION OF MERCURY-CONTAINING WASTES FOR RECYCLING SAID WASTES Russian patent published in 2010 - IPC C22B7/00 C22B43/00 C22B3/04 

FIELD: chemistry.

SUBSTANCE: method involves treatment of wastes with a calcium polysulphide solution. Before treatment with the calcium polysulphide solution, the wastes are mixed with an oxidising agent which contains active chlorine in amount of 0.15-10.0 % of the weight of the wastes. Water is then added and the mixture is held. The obtained mixture is treated with a calcium polysulphide solution in ratio of calcium polysulphide solution to the mixture equal to 1-4:10 wt % respectively, and the reaction mixture is then held.

EFFECT: avoiding the need to use complex equipment, recycled wastes which are converted from hazard class 1 to hazard class 4 contain mercury sulphide inclusions which are not hazardous to the environment and are safe for disposal.

5 cl, 1 tbl, 9 ex