Extraction of Lithium from Spodumene by Alkali fusion

622.33;

공과대학 에너지시스템공학부 ;

University:서울대학교 대학원

关键词: 622.33;   

Others  :  http://s-space.snu.ac.kr/bitstream/10371/143846/1/000000152139.pdf

美国|英语

来源: Seoul National University Open Repository

【 摘 要 】

furthermore, the leaching conditions were 5min leaching time and 25 °C leaching temperature. The extraction efficiency of lithium under these conditions was 63.88%. In the Na2CO3 fusion test, the fusion temperature was fixed at 850 °C. At this fusion temperature, the optimum fusion conditions for were 60 min fusion time and 1:1 Na2CO3/sample. The leaching conditions were 5 h leaching time and 1.5 M sulfuric acid concentration. The results of the sodium carbonate fusion test under these conditions show that 99.98% of the lithium in the samples was extracted. However, all the silicon and 75% of the aluminum in the sample was extracted along with lithium. After leaching with 1.5M hydrochloric acid under the same fusion conditions, the lithium extraction was lower than sulfuric acid. However, it was possible to remove silicon and aluminum by adding Na2CO3 into the leachate.In summary, the optimum fusion and leaching conditions were investigated to extract a high percentage of lithium from spodumene by the alkali fusion method. The results show that almost of the 100% lithium in the samples was extracted with Na2CO3 fusion and sulfuric acid leaching. However considering impurities, the optimum conditions were using 1.5M of hydrochloric acid in the leaching stage followed by removal of Si and Al by adding Na2CO3. This experiment was conducted at a lower temperature than that of the existing processes with no phase-conversion stage. Therefore, it is a better process in terms of the energy consumption and simplicity of the process.