Optimization Trials And Mechanism, Shandong Xincheng Gold Flotation Gold Concentrate Cyanidation Leaching

Strengthening gold cyanide leaching by adding chemical reagents has become a main investigating direction and has been alternative to optimize cyanide leaching. The effect of gold cyanide leaching gets improved and the dosage of cyanide gets reduced.Strengthening geld leaching by adding chemical reagents had displayed favorable effect and great future. The technology of strengthening gold leaching can make full use of resource and reduce the cost of production. If it is used in recovery of gold ore, it will play an important role in the sustainable development of gold ore resources in our country.The laboratory tests and commercial practice were carried out on gold floatation concentrate from Xincheng Gold Mine of Shandong Gold Group Limited Company.The leaching time 01 laboratory tests had only two third of general gold cyanide leaching, and gold leaching ratio increased 1. 2~1.43%, NaCN dosage reduced 1~3 kg/t.The results of conmercial practice showed that strengthening gold cyanide leaching after add ing mixed reagents (C+X+HA) could reduce the dosage of NaCN over 3 kg/t while gold recovery remained the same . The consistency of Of decreased 143~448 mg/1 and the consistency of SOT decreased 15'?92 mg/1 than general gold cyanide leaching. These are the effects of HA passivating the surface of sulphide minerals and leads salts avoid efficiently the S2" in pulp. The concentration of free cyanide liberated reduced 257~840 mg/1. The results above showed that strengthening gold cyanide leaching by adding chemical reagents had achieved the aim to reduce NaCN dosage and economy benefit get improved.The effect of associate minerals in gold ore was analyzed in details.Some sulphide minerals in ore, as pyrite, pyrrhotite, marcasite, chalcopyrite etc. , can consume a great of cyanide and oxygen and produce dissoluble sulphide (S2"). The dissoluble sulphide (S2") can form sulfureted film which prevent gold cyanide leaching in gold minerals surface. The zinc blende helps to gold cyanide leaching and has a less neagtive effect. The dissoluble NaPbOz that produced by galenite can accelerate gold cyanide leaching.The mechanism of HA and lead salts were evaluated in depth. The HA can improve gold recovery, speed kinetics processing of gold cyanide leaching and passivate surface of sulphide minerals. The catalysis mechanism of Fe" to HA is a reaction of liberated group. Liberated group strengthening is one of important factor that shorten the times of gold cyanide leaching. Lead salts can dissolve gold as oxide and negative effect of dissoluble sulphide (S*~). The radiative reaction between Pb2+ and sulphide minerals can raise temperature of pulp. The raise of pulp temperature can promote disassemble of HA, accelerate dissolving gold, and damaged sulphide enwrapping gold.