Study On Acid Leaching Of Gold,silver And Copper In Sulphide Calcined Sand

Different calcination silver concentrates have different natural selection and leaching methods.For the silver concentrate containing metal copper and iron and other trace impurities,the selection of leaching methods is limited.The advantages and disadvantages of comprehensive leaching reagent,the thiourea as leaching reagent,select the two stage leaching,sulfuric acid and sulfuric acid leaching of a thiourea two stage leaching,the leaching conditions were optimized in each leaching,an important concern for each ion leaching analyses the leaching rate,results were as follows:In a period of sulfuric acid leaching,respectively on the dosage of sulfuric acid,leaching time,leaching temperature,liquid-solid ratio was optimized by single factor experiment,The main ions to be leached are copper.the optimum leaching conditions according to the experimental results obtained by sulfuric acid dosage of 1.4g,liquid-solid ratio 4:1(40mL:10g),extraction temperature is 40 DEG C,leaching time is 120min.At this time,the leaching rate of copper is 92.49%,and the leaching rate of iron is 8.11%.Then the optimized conditions are amplified and the leaching experiments are carried out in large quantities,and the leaching of the raw ore is provided for the two stage leaching.In a period of thiourea leaching,the sulfuric acid concentration,leaching time,liquid-solid ratio,thiourea concentration and external Fe3+concentration were optimized by single factor experiment.Meanwhile,in order to consider the influence of impurities in the ore on thiourea consumption,In the experiment of Fe3+ concentration,two cases of the liquid solid ratio are considered.Finally,according to the experimental results,the best leaching conditions are as follows:sulfuric acid concentration is 15g/L,leaching time is 120min,thiourea concentration is 18g/L,when the liquid solid ratio is 60:1,when the applied Fe3+concentration is 2.8g/L,the leaching rate of gold and silver in slag phase analysis is 95.26%and 51.26%respectively.When the liquid solid ratio is 5:1,when the added Fe3+concentration is 11.2g/L,the other conditions are the optimized conditions.The leaching rate of gold and silver by slag phase analysis is 92.20%and 46.16%respectively.The results show that Fe3+shows a completely different state of leaching results under the ratio of liquid to solid and the ratio of small liquid to solid.By subsection leaching,after a period of leaching,it is very good to remove the copper which has a great influence on thiourea leaching,which is more beneficial to the improvement of the leaching rate of silver in the two stage leaching.