| Since entering the 21st century, the mines have been continuously mined. Pursuing of the single economic benefits causes the reduction of thallium resource contained in ore; meanwhile the left thallium in the slag is released into the environment, which causes the serious regional pollution. Along with the discovery of the Thallium Department of High Temperature material, the thallium is more used in electronics, military, modern high technology and medical industry as well. Therefore, extracting the thallium from the slag can not only prevent environmental pollution but apply fully the value of thallium as well.There are some traditional methods to extract the thallium:ion exchange, solvent extraction, replacement precipitation, crystallization, electrolysis and dressing-metallurgy method which have to require tedious separation and enrichment. In this paper, the author first introduces the vacuum distillation to extract the thallium, which takes the advantages of short process, low energy consumption, pollution-free, non-middle-residue, low labor intensity and low production costs. Based on the different boiling point and vapor pressure in thallium and metals contained thallium, the author gets the conclusion that thallium can be separated from other metals. The extraction process can be divided into three steps. The ranges of Cd-T1, T1-Cu and T1-Pb can be estimated through the research data of T1-i system, working out theβT1, judging the possibility of the separation between Pb and T1. Theoretically, T1 can be separated from Cd, Pb, Zn, Fe, Cu, Ni, and Si. Experiments analise the influence on purification from vacuum, charge, duration and temperature of the distillation, experiment showed that the impact from vacuum and distillation temperature on purification is relatively large.40-50g charge is used to do experiment whose temperature is 560°,40 minutes,8-40 vacuum. Among the steamed out materials, the percentage of Cd is 98.04%, T1 is 66%. The Cd is almost evaporated out while little T1 is out. Among the first residues, the T1 takes up 74.42%。Taking 30-40g residues to distil second time,1012℃,50 minutes,8-40Pa. The percentage of T1 is high to 93.4% and the percentage of Fe is 0.11%, S10.0054%, Ni55.56%, Cu 44.06%.In summary, the experiments research provides the valuable raw data for the thallium experiment, which laid the foundation for the later semi-industry and testifying the III theoretical analysis about extraction of thallium, at the same time opening the up an integrated new theology to recycle thallium. |
