| Lead and zinc metals are important non-ferrous metals in China.They are industrial raw materials second only to iron,aluminum and copper.They are widely used in national economic construction.China’s lead and zinc production ranks first in the world,and its reserves rank second in the world.Most of them are complex mosaic symbiotic polymetallic ores,often accompanied by precious metals such as gold and silver,which have comprehensive recycling value.Lead sulfide and zinc sulfide minerals are the main sources of lead and zinc metals.However,with the increasing consumption of lead and zinc metals and the large-scale exploitation of lead-zinc mines,the ore properties of most lead-zinc mines have changed significantly,and the easy-to-float lead-zinc sulfide mineral resources are exhausted.Therefore,the efficient recovery and utilization of complex refractory mixed lead-zinc ore is very important.Due to the close symbiosis of lead and zinc,the complex dissemination relationship and the high oxidation rate of mixed lead-zinc ore,it is difficult to separate lead and zinc in the flotation process and the flotation index is poor.Therefore,it is necessary to develop efficient flotation reagents and new technologies suitable for such lead-zinc resources.In this paper,the low grade and high oxidation rate lead-zinc ore in Inner Mongolia was taken as the research object,and the process mineralogy was studied.Based on the process mineralogy,the lead-zinc flotation separation and enrichment test,the lead concentrate regrinding and reconcentration test,and the lead flotation tailings were systematically carried out.Experimental study on zinc separation,and obtained better flotation test indicators than on-site.The results of process mineralogy show that the valuable elements in the raw ore are mainly lead（3.29%）,zinc（2.33%）and silver（220.5 g/t）.The lead-zinc minerals in the ore mainly exist in the form of galena,cerussite,sphalerite and hemimorphite.The oxidation rate of lead is 28.08%and the oxidation rate of zinc is 23.85%.Other impurities are mainly Si O2,followed by Al2O3,Mg O and Ca O,which are mainly composed of gangue minerals such as quartz,potassium feldspar and kaolinite.Due to the high oxidation rate of lead and zinc,the particle size of lead-zinc minerals is fine and the separation is difficult.Therefore,it is difficult to achieve effective separation and efficient enrichment of the ore by conventional flotation reagents.The results of lead-zinc flotation separation test show that zinc minerals can be effectively inhibited by using zinc sulfate,sodium sulfite,sodium sulfide and JL-1 as mixed inhibitors,and the addition of JL-1 is beneficial to lead-zinc separation.The use of ethyl dithiocarbamate,ammonium dibutyl dithiophosphate and ethyl xanthate as mixed collectors can selectively recover lead minerals in ores and reduce the phenomenon of lead-zinc mutual inclusion,indicating that the lead-zinc separation effect of mixed collectors is better than that of single collectors.Among them,the grinding fineness in the roughing was determined to be 70%in the-0.074 mm fraction,the dosage of zinc sulfate was 3000 g/t,the dosage of sodium sulfite was1250 g/t,the dosage of sodium sulfide was 200 g/t,the dosage of JL-1 was 100 g/t,the dosage of ethyl sulfide nitrogen was 100 g/t,the dosage of ammonium dibutyl dithiophosphate was 40 g/t,and the dosage of ethyl xanthate was 20 g/t.Under the lead-zinc separation test process of’one roughing,two cleaning and two scavenging’,the lead concentrate with lead grade of 58.50%and lead recovery of 84.16%was obtained in the small closed-circuit test in the laboratory.The grade of zinc in lead concentrate is only 4.36%,and the flotation index is better than the field index.The results of zinc flotation test of lead flotation tailings show that the mixed activator of copper sulfate and lead nitrate can effectively activate the deeply inhibited zinc minerals in the ore,and its activation effect is better than that of single copper sulfate or lead nitrate.At the same time,the mixed collector of ammonium dibutyl dithiophosphate and butyl xanthate can improve the flotation recovery of zinc minerals which are deeply inhibited,and its collection ability is better than that of single collector.Among them,the slurry p H=10,the dosage of copper sulfate is 450g/t,the dosage of lead nitrate is 300 g/t,the dosage of ammonium dibutyl dithiophosphate is 60 g/t,and the dosage of butyl xanthate is 400 g/t.Under the closed-circuit process of’one roughing,two cleaning and one scavenging’,the zinc concentrate with zinc grade of 48.87%and zinc recovery of 78.29%was obtained in the small closed-circuit test in the laboratory,and the flotation index was better than the field index.In this paper,aiming at the low grade and high oxidation rate lead-zinc ore in Inner Mongolia,the addition of mixed inhibitors realizes the efficient separation of lead and zinc in the ore,reduces the phenomenon of lead and zinc mutual inclusion,and improves the flotation recovery of lead in the ore.The use of mixed activators enhances the activation effect of zinc minerals that are deeply inhibited in the ore,which is beneficial to the adsorption of collectors and target minerals.At the same time,the use of mixed collectors can selectively recover valuable metals in the ore and improve the comprehensive index of lead,zinc and associated metal silver.It can be seen that the mixed use of flotation reagents can improve the separation and enrichment effect of complex refractory lead-zinc ore,and provide reference for the efficient recovery of similar lead-zinc resources. |
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