Study On The Mechanism Of Synergistic Leaching Of Refractory Gold Ore In Guizhou By Potassium Chlorate And Bleaching Powde

With the continuous exploitation and utilization of global gold resources,high-grade and easily beneficiated gold resources are increasingly exhausted,and refractory gold deposits with huge reserves are gradually becoming an important raw material for gold production industry.Due to the extremely fine particle size and complex occurrence state of gold in this kind of gold ores,accompanied by the influence of impurity elements and carbon bearing substances,the recovery rate of gold in traditional cyanide leaching process is generally low.In view of how to extract valuable elements efficiently and environmentally,scholars of various countries have put forward a variety of non-cyanide gold extraction methods,but most of them are not suitable for practical production.Based on refractory gold ore in guizhou as the research object,on the basis of theoretical analysis is feasible,and put forward the potassium chlorate bleaching powder together a leaching of refractory gold ore in guizhou new method of potassium chlorate on the one hand,as a strong oxidizer can efficient solutions from gold sulfide on the gold package,on the other hand also can be used as leaching agent not carried out in cooperation with the bleaching powder of cheap non-toxic cyanide leaching of gold,So as to achieve efficient environmental protection of the purpose of gold.The main research work and achievements of this paper are as follows:(1)Through the thermodynamic analysis of pyrite,arsenopyrite and other gold-bearing minerals and the thermodynamic analysis of potassium chlorate and bleaching powder to dissolve gold,theoretically proved the feasibility of potassium chlorate and bleaching powder gold leaching.(2)The dissolution mechanism of mineral carbon paste electrode and gold electrode in potassium chlorate system and bleaching powder system was studied by Tafel polarization curve and electrochemical impedance spectroscopy(EIS).The electrochemical experimental results again verified the feasibility of leaching gold with potassium chlorate and bleaching powder.It also provides data support for the next single factor actual gold leaching experiment of potassium chlorate and bleaching powder system.(3)The single factor gold leaching experiment results of potassium chlorate show that the best gold leaching conditions are as follows: Under the conditions of potassium chlorate concentration 0.15mol/L,reaction temperature 25℃,reaction pH=8 and reaction for 4h,the gold leaching rate is up to 45.19%.The experimental results are consistent with the electrochemical experiment results of potassium chlorate system,which further verifies the feasibility of potassium chlorate gold leaching.(4)the single factor of bleaching powder gold leaching experiments show that the best gold leaching conditions as follows: the amount of bleaching powder 30 g,temperature 25 ℃,reaction pH = 13,4 h,under the condition of the gold leaching rate up to 58.63%,the experimental result is consistent with experimental results of electrochemical bleaching powder system,further verify the feasibility of bleaching powder gold leaching.(5)The experimental results of response surface method of potassium chlorate and bleaching powder in the leaching of refractory gold in Guizhou show that potassium chlorate and bleaching powder in the leaching of gold has a good effect,the highest gold leaching rate can reach 74.44%.The order of the influencing factors of leaching gold is as follows: the amount of bleaching powder > the concentration of potassium chlorate > the reaction temperature.At the same time,the optimum technological conditions for leaching refractory gold ore in Guizhou are as follows:concentration of potassium chlorate 0.15mol/L,addition of bleach 27.16 g,reaction temperature 30℃.