The main reactions of leaching strontium sulfide concentrate and brittle sulphur bismuth lead concentrate with Na 2 S solution are: However, Na 2 S can be strongly hydrolyzed in water: The NaHS produced by hydrolysis is oxidized by oxygen in the air to form sodium polysulfide Na 2 S 2 , thereby reducing the action of Na 2 S. Therefore, a certain amount of NaOH should be added to the Na 2 S leachate to inhibit the two types. Adverse reactions that affect leaching efficiency. Experiments have shown that in the case of adding NaOH, the amount of Na 2 S is slightly higher than the theoretical amount, and a high leaching rate can be obtained. Therefore, the leaching agent actually used is Na 2 S+NaOH. When Na 2 S is insufficient, NaOH also has a certain dissolution effect on Sb 2 S 3 , and the reaction is: The Na 2 S+NaOH mixed solution also dissolves Sb 2 O 3 , and the reaction is carried out in two steps: The high-valent oxides Sb 2 O 4 and Sb 2 O 3 do not dissolve in the Na 2 S solution. Associated metal antimony sulfide concentrate, in addition to Hg, and Ag, Cu, Pb, Fe, Zn, Ag and other immune Na 2 S dissolved in the solution, enriched in the slag during leaching. The leaching reaction of sulfides of Hg and As is as follows: Sulfide of arsenic can also be dissolved by NaOH, but arsenic in the arsenopyrite (FeAsS) is insoluble. Diaphragm Pump Diaphragm Pump,Electric Diaphragm Pump,Plastic Diaphragm Pump,Pneumatic Diaphragm Pump Shijiazhuang Boda Industrial Pump Co., Ltd. , https://www.mineralslurrypump.com