| China is rich in lead-zinc oxide ore resources,which is a large country in the world.At present,the effect of conventional beneficiation method on the separation of lead-zinc oxide ore is not ideal,but the metallurgical process is difficult to deal with economically and involves environmental pollution,so it has not been reasonably developed and utilized for a long time.To improve the utilization rate of lead-zinc oxide ore,this paper takes the typical lead-zinc oxide ore as the research object,and uses the pure minerals of smithsonite and cerussite.Using the technical route of hydrothermal sulfurization flotation and the sulfur was used as the sulfidation agent in the hydrothermal sulfurization processing,two kinds of oxidized minerals get high-efficiency sulfurization,which can be converted into lead sulfide and zinc with better floatability.Then the traditional flotation method of recovery sulfide ore is used,and finally the rationality of the result is characterized by combining the flotation recovery and analysis.In this paper,the hydrothermal sulfuration thermodynamics of cerussite and smithsonite was calculated.Based on the thermodynamic analysis,the reaction law of sulfuration of smithsonite and cerussite was studied,and the thermodynamic conditions favorable for the sulfuration of the two minerals were found out.The results show that under a certain temperature,smithsonite and cerussite can react with sulfur to form zinc sulfide and lead sulfide,and the rise of temperature is conducive to the conversion of zinc oxide and lead oxide,which indicates that the conversion of lead-zinc oxide to surface sulfide is feasible in thermomechanics.Developing the hydrothermal sulfuration-flotation experiments of smithsonite and cerussite.The results show that the amount of sublimated sulfur,reaction temperature,reaction time,reaction p H,stirring speed,and liquid-solid ratio have an important influence on the flotation behavior of hydrothermal products.The optimum conditions of hydrothermal sulfurization of smithsonite are as follows: the molar ratio of sublimated sulfur to smithsonite is 1.3 times,the reaction temperature is 215?,the reaction time is 180 min,the reaction p H is about 9,the rotation speed is 550 rpm,and the liquid-solid ratio is 4:1.Under these conditions,the highest recovery rate of the hydrothermal product is 92% by flotation.The optimum conditions of hydrothermal sulfurization of cerussite are as follows: the molar ratio of sulfur to cerussite is 1.0 times,the reaction temperature is 180?,the reaction time is 120 min,the reaction p H is about 9,the rotating speed is 550 rpm,and the liquid-solid ratio is 4:1.Under these conditions,the hydrothermal product has obtained 84% recovery by flotation.The floatability of the roasted product is good.XRD,XPS,IR,EPMA,adsorption capacity and contact angle were used to analyze the surface and composition of smithsonite and cerussite after hydrothermal sulfuration.XRD phase analysis showed that Zn S and Pb S were formed on the surface of smithsonite and cerussite respectively when a small amount of sulfur was added;EPMA analysis showed that the atomic concentration of sulfur increased with the gradual addition of sulfur and the atomic concentration of carbon and oxygen disappeared gradually after hydrothermal sulfuration of the two minerals.At the same time,a layer of sulfide film separated from the inner part appeared on the surface and gradually extended to the inner part of the mineral with the addition of sulfur;XPS analysis shows that the product of zinc mainly consists of zinc sulfide and a small amount of two kinds of zinc sulfide and sulfate,and the product of lead mainly consists of lead sulfide and a small amount of two kinds of lead sulfide and two kinds of sulfate.At the same time,with the addition of sulfur,the relative content of S in sulfide minerals increases significantly,while the relative content of C and O decreases significantly;The infrared spectrum analysis shows that the characteristic absorption peak of sulfide appears in both minerals after hydrothermal high efficiency sulfurization.At the same time,there are obvious characteristic peaks of xanthate absorption before and after adding reagents,which proves that xanthate chemical absorption occurs on the surface of sulfide during flotation;The analysis of adsorption capacity shows that the amount of xanthate adsorbed on the surface of hydrothermal products of smithsonite and cerussite increased gradually with the addition of sulfur.At the same time,it was found that the adsorption capacity of zinc product to xanthate was significantly higher than that of non activated ore,while the adsorption capacity of lead product to xanthate was significantly higher than that of non collected product.The contact angle analysis shows that with the addition of sulfur,the contact angle and hydrophobicity of hydrothermal products increase gradually.At the same time,it was found that the hydrophobicity of zinc product after activation was stronger than that of lead product after adding xanthate. |
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