Lithium Mica Mother Liquid Leaching Solvent Extraction In The Experimental Study

This study summarized extracting lithium and impurity removal methods in the course oflithium metallurgy, especially the application of solvent extraction in lithium metallurgy. Thispaper introduced the property of P507and naphthenic acid as well as their applications in metalextraction. Because of leaching solution which obtained in the process of lepidolite sulfatepreparation of lithium carbonate, kinds of metal impurities and characteristics of large content,without the traditional chemical purification process, the present study discussed how to refineand remove impurities from leaching solution via solvent extraction. Moreover, P507andnaphthenic acid extraction systems were studied separately. And the mixing extraction,sequential extraction, comprehensive recovery of organic phase were all studied in this sduty.In the study of impurity removal experiment in naphthenic acid extraction system, theideal conditions were optimized as the naphthenic（HA） acid concentration0.6mol/L,suffocated kerosene as thinner, compared （O/A=2）, extraction temperature30℃, oscillationtime of6minutes, specification rate of60%, feed solution pH2.5, the oscillation rate of150beats/minute and single-stage extraction. In the above conditions, the experiment repeated forthree times. The results of the experiments followed as the contents of Al³⁺,Fe³⁺,Li⁺6.88mg/L,0.80mg/L,7.06g/L, extraction rates99.9%,98.10%,1.53%, the content of Mn²⁺1.07g/L andthe extraction rate was approximately zero. The selective extraction of manganese ions was lowwhen naphthenic acid as extract ant, and it was difficult to extract the manganese ions into theorganic phase.In the study of impurity removal experimental in P507extraction system, it divided into twoparts which were ammonia and sodium hydroxide specification. Through contrasting, the effectof extractant in sodium hydroxide specification extraction was better than that in ammoniaspecification. The factors which influenced extraction rate of metal ions more greatly, wereinvestigated. According to the main influenced factors, orthogonal experiment was made. Theoptimal extraction conditions obtained as the P507concentration2.0mol/L, compared（O/A=2/3）,6minutes the extraction time,30℃the reaction temperature,the shake speed of150time/min,pH=2.5,60%specification rate and single stage extraction. Under these conditions, theextractions rate of aluminum, manganese, iron were99%,97%,95%to99%respectively. Andloss of lithium-ion controlled was less than5%as well as rubidium and cesium extraction ratewere less than1percent. The magnify experiments （10times） with the same conditions alsoachieved better extraction results.By contrasting the experiments of water wash and reverse extraction, it was found that thewashing effects of extracted complex in those two extraction systems were poor because someimpurity ions were washed down with concomitant lithium. The organic phase in P507 extraction system had significant reextraction effect. With higher concentrations of sulfuric acidsolution as stripping agent and appropriate O/A, impurity ions in organic phase were removedthoroughly.The experiments of impurity removal study of blend and subsection extraction: theexperimental results showed that the extraction effects in both methods were not ideal.Although the two methods were all significant in extracting impurity removal as well as highextraction rate of lithium, causeing large number of lithium losing.In the study of comprehensive recovery experiment about organic phase, the organic phasewhich was after extraction can be used again by pickling and washing processing. Theextraction effect of Neonatal organic phase closed to the new ones.