Development of gold leaching process - ultrasonic leaching m
2020-07-02 09:37Introduction：The technique of ultrasonic enhanced cyanide leaching opens a new way for rapid leaching. The precondition of ultrasonic assisted leaching is that leaching speed is controlled by diffusion.When solid gold is dissolved in cyanide solution,
The technique of ultrasonic enhanced cyanide leaching opens a new way for rapid leaching.The precondition of ultrasonic assisted leaching is that leaching speed is controlled by diffusion.When solid gold is dissolved in cyanide solution, complex ion Au(CN)2- is quickly formed on the gold surface, and a saturated solution layer of Au(CN)2- is formed near the surface, in which O2 and CN- drop sharply.The formation of the saturated layer hinders the dissolution of gold.In order to further dissolve the gold, the saturated layer should be destroyed continuously to accelerate the diffusion rate of Au(CN)2- to the gold surface and O2 and CN- to the gold surface.Conventional stirring cyanidation leaching has limited strength in accelerating the diffusion rate of ions, so the leaching rate is relatively slow.It is more difficult for ore with passivating film formed on the surface of gold grain to leach.Ultrasonic assisted leaching is aimed at the problems mentioned above. Fluid mechanics and acoustic chemistry are adopted to rapidly eliminate the saturated layer and passivating film that prevent gold from continuing to dissolve in cyanide solution and accelerate the leaching of gold.
Ultrasonic immersion of key equipment are three generator, A type and R type generator will be in the form of distributed jet of compressed air into pulp, such not only can improve the solubility in the solution and the distribution uniformity of O2, and under the action of A strong jet, autogenous grinding ore particles, destroying the saturated layer and the passivation film.S type generator is mainly generated by sound energy " cavitation "," cavitation" disappear in a flash to produce the high temperature and high pressure, impact on the solid surface to form a micro jet, the jet speed can reach above 1000 m/ns, strong local denudation in the solid surface, strengthened the mass transfer effect, keeping a solid surface high reactivity, not only greatly improve the reaction speed, and make the refractory gold ore leaching rate can be improved.
