Study On Preparation Of Nanometer Zinc Oxide From Zinc Tail Of A Silver Ore

With the increasing requirements of modern society for the environment,the disposal of tailings in the mining industry has become extremely important.The utilization of tailings tailings can not only alleviate the crisis of increasing depletion of resources,but also avoid damage to the ecological environment.As an important basic metal raw material in the construction of the national economy,zinc resources are in short supply only by relying on zinc ore smelting.Therefore,the secondary use of various zinc-containing materials is an inevitable trend.This article uses zinc tailings in the tailings of a silver mining company as raw materials.After wet leaching of zinc to remove impurities,the direct precipitation method is used to prepare nano zinc oxide materials.The operation is simple and the pollution to the environment is reduced.It can not only solve the problem of tailings storage,but also reuse the zinc resources in the tailings,which has practical significance in the utilization of tailings.The experimental conclusion is as follows:1.By EDS spectr?m analysis and XRD analysis of zinc tailings samples,the composition of zinc tailings is relatively simple.The slag contains 44.38%zinc.The main impurities include iron,lead,copper and al?min?m.Zinc sulfide;zinc sulfide is basically converted into zinc oxide in the sample after roasting;2.The zinc in the sample was recovered by dilute sulfuric acid direct leaching method.The effects of the initial concentration of sulfuric acid,leaching temperature,liquid-solid ratio,and leaching time on the leaching rate of zinc were investigated.Through single factor analysis,the optimal leaching conditions were determined:initial sulfuric acid concentration of 1.0 mol/L,reaction temperature of 80?,liquid-solid ratio of 14:1,and leaching time of90 min.Under the optimal leaching conditions,the zinc leaching rate in the sample was92.85%;3.The kinetic principle of the leaching process was studied.By substituting the data of zinc leaching rate with reaction time at different temperatures and different initial concentrations of sulfuric acid,it was found that the leaching process of the sample conformed to the Avrami kinetic model.The dynamic equation of the proce ss is-ln(1-?)=10.08c.exp(-6.03×10/RT)t.?4.Impurity treatment was performed on the leaching solution,Fe²⁺in the leaching solution was oxidized to Fe³⁺using H₂O₂,and then the p H was adjusted to remove Fe³⁺and Al³⁺simultaneously.The amount of H₂O₂ added per 100m L of leaching solution,p H value,reaction temperature and reaction time,etc.The effect of al?min?m removal rate.By single factor analysis,the best conditions for iron and al?min?m removal were determined:2 m L of H₂O₂ per 100 m L of leaching solution,p H value of 4.5,reaction temperature of 80?,it took 90 minutes to react,and the iron removal capacity was up to 99.10%.The removal rate was 99.13%.Copper and lead were removed using zinc powder replacement.The effects of the amount of zinc powder per 100 m L of leaching solution,reaction temperature,and reaction time on the removal rate of copper and lead were investigated.Through single factor analysis,the best conditions for removing copper and lead were determined:0.15 g zinc powder was added per 100 m L of leaching solution,The reaction temperature was 60 degrees Celsius,the time was one hour,in the best state,the copper removal rate was 99.83%,and the lead removal The rate is 96.29%.5.The refined zinc sulfate solution was used as the raw material to prepare nanometer zinc oxide products by direct precipitation method.The effects of the amount ratio of NH₄HCO₃ and Zn²⁺,reaction temperature and reaction time on the secondary particle size and zinc precipitation rate were investigated.The optimal reaction process conditions were determined as follows:the ratio of the amount of NH₄HCO₃ and Zn²⁺was 2.4,the reaction temperature was set to 30 degrees Celsius,and the reaction time was 30 min.Under this condition,the secondary particle size of the product was 0.13?m,and the zinc precipitation rate was 98.85%.XRD component analysis and IR analysis were performed on the precursor under optimal conditions,and the main phase composition of the precursor was determined to be basic zinc carbonate.Under the optimal reaction conditions,the temperature and time of calcination had a certain influence on the industry,and the outstanding performance was the influence on the particle size and purity,and the comparison of the products before and after the addition of the dispersant polyethylene glycol 400 were investigated.The optimized conditions were determined as follows:the calcination temperature was 550?,the calcination time was 2.5 h,and the product with a smaller secondary particle size was obtained after adding the dispersant polyethylene glycol 400.The average particle size reached 55 nm and the product purity reached 98.70%.6.By XRD and SEM characterization,the diffraction peaks of the obtained product basically coincide with the diffraction peaks of Zn O(standard card PDF#36-1451).The powder is spherical or spheroidal,and the distribution is more uniform.The determination of various product indicators under the optimal conditions showed that the purity of the experimental product zinc oxide reached the second-class standard in the GB/T19589-2004nanometer zinc oxide standard,and all other indicators met or even surpassed the third-class standard.