| Lithium is an important chemical raw material,which is widely used in battery industry,glass industry,ceramic industry,aluminum industry,refrigerant,lubricant,radio and television industry and other emerging areas of nuclear industry.In recent years,with the strategic position of the highlights countries around the world pay attention to lithium resources.Lithium has a very high value of application,however,as a trace element lithium reserves are limited.At present,the global demand for lithium metal is very urgent,and China's demand for lithium is very large,so lithium is in short supply for a long time.Therefore,preparation of lithium and related compounds is particularly important.At present,one of the largest industrial waste residue in China is the fly ash,and the annual emissions reached hundreds of millions of tons,the accumulation of a large number of fly ash will not only cause serious damage to the natural ecological environment but also pollut the groundwater.Therefore,the comprehensive utilization of fly ash is more and more important in the world.Recently,researchers have found that Zhungeer coal and Pingshuo Mine Coal in lithium associated minerals and achieve extraordinary enrichment associated with industrial grade lithium,and coal with lithium has become a research hotspot in the University,the study of extracting lithium from fly ash also got everyone's attention.Thus,the comprehensive utilization of fly ash,that is to realize the resource and fine utilization of fly ash,which not only can save the cost of mining and the development of circular economy and economy,but also can reduce the ecological damage to the environment,that is to achieve the purpose of treating fly ash pollution.Taking Pingshuo Mine desiliconized fly ash and sodium carbonate as raw material of fly ash on dissolution test of various factors on the extraction rate of lithium,at the same time in order to improve the extraction rate of lithium to save cost and reduce energy consumption.Firstly,analyse the chemical composition and phase morphology of various oxides of desiliconized fly ash,So as to determine the experimental method for the dissolution of the fly ash.In the case of economic,practical and high extraction rate,the following extraction scheme is adopted: alkali method,sintering and dilute alkali dissolution.Through the single factor and orthogonal experiment,the influence ofvarious factors on the extraction rate of lithium was investigated,and the optimum process conditions of the roasting process and the leaching process were determined:(1)Roasting process: The mass ratio of fly ash,sodium carbonate and calcium carbonate was 1.0:0.8:1.0,the calcination temperature was 1200?,and the calcination time was 80 min.Under this experimental condition,the leaching rate of lithium was58.49%(2)Leaching process: 2.0 L 8% sodium carbonate solution at 150? conditions for40 minutes,under this condition,the extraction rate of lithium reached 61.52%.(3)In the process of lithium carbonate precipitation,the final yield was 95.67%,and the final yield was 36.56%. |
PDF Full Text Request