Study On Physical Sorting Process Of Valuable Mineral Resources In Zinc Kiln Residue

Zinc kiln slag is a valuable secondary resources,which contains many valuable metals.But its comprehensive recycling is regarded as a technical problem.Recovery of valuable metals from zinc kiln slag is very significant,as mineral resources is becoming exhausted.Experimental research was carried out in this paper on the comprehensive recovery of valuable elements from zinc kiln slag.In order to ascertain the elemental composition of zinc kiln slag,the mineral composition of zinc kiln slag,the symbiotic relationship of main minerals and the occurrence states of main elements,technological mineralogy analysis was made for the zinc kiln slag.The results indicate that the valuable elements:Cu,Ag,Fe.and Zn are rather rich in this slag,and Cu mainly exists in the form of chalcopyrite,Ag mainly exists in the form of silver and silver sulfide,Fe mainly exists in the form of almandine,iron and pyrrhotite,Zn mainly exists in the form of sphalerite.Based on the property of the zinc kiln slag and extensive literature,flotation method was adopted in order to have an exhaustive research on the recovery of copper and silver which exist in zinc kiln slag.The results are shown as following:In this paper,the flotation process of zinc kiln slag was studied,and the influence of grinding fineness,regulator's dosages,collector's species and dosages,frother's species,flotation flow sheet and other factors on flotation indexes was analysed respectively.Finally,the optimum technological parameter of zinc kiln slag flotation was determined as following:one roughing,one cleaning and one scavenging was adopted,the flotation time of 4 minutes,the optimum reagent systems for roughing:the reagent dosage of 100g/t lead nitrate,600g/t butyl xanthate,200g/t butylamine dithiophosphate,100g/tpine oil;the optimum reagent systems for cleaning:the reagent dosage of 80g/t butyl xanthate,50g/t pine oil;the optimum reagent systems for scavenging:the reagent dosage of 40g/t lead nitrate,150g/t butyl xanthate,75g/t butylamine dithiophosphate,50g/t pine oil.According to properties of the zinc kiln slag,a floation solution was proposed as“one roughing,one cleaning,one scavenging and the middlings return orderly".Under the optimum conditions,a concentrate can be obtained,in which the total of Cu is 6.00%and recovery ratio of 73.84%,the total of Ag is 1111.30g/t and recovery ratio of 76.41%,the total of Au is 0.80g/t and recovery ratio of 32.16%.The mineral processing index is fine.Due to dissociation inadequacy,the effective separation of copper and zinc from zinc kiln slag is difficult,which results in that indium-zinc concentrate can not be obtained individually.Iron and iron minerals can be recycled from flotation tailings by magnetic separation,it can get the 82.61%iron concentrate with 63.91%recovery,but there exsist excessive level of sulfur and arsenic in iron concentrate.Sulfur can be removed mostly from iron concentrate by flotation method,but arsenic which exists in iron concentrate can not be removed by mineral processing method.A relatively simple technological process and reagent system is adopted in this paper,which the better synthetic recovery indexes can be obtained.Simultaneously,this paper has provided certain basis for the mineral processing technology of zinc kiln slag.