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Into the 21st century, due to the mines continue to be mined, the pursuit of a single metal smelting inefficient economic benefits, leading to diminishing resources associated in the ore thallium, thallium left in the slag are released into the environment, resulting in a serious regional pollution. With the discovery of thallium-based high-temperature superconducting materials, thallium more and more used in the electronics industry, military industry, modern Gregorian technology and medical fields. Therefore, extracted from the smelting slag thallium can not only prevent environmental pollution, while the value of the thallium be fully applied. Mention thallium ion exchange, solvent extraction, replacement precipitation, crystallization, electrolysis, and dressing and smelting joint law, the need to go through the tedious separation and enrichment technology, in order to extract thallium. This is the first vacuum distillation extraction of thallium, compared with traditional methods, with a short process, low energy consumption, no pollution, no intermediate slag, low labor intensity, low cost production. Of thallium and thallium-containing slag metal boiling point and vapor pressure, theoretically analyzed, thallium and other metals are separable, and three steps purified thallium. Cd-Tl, Tl-Cu, Tl-Pb in the gas phase in the range estimated from the TL-i binary system yi research data based on the possibility of separation of Pb, Tl, by values ??obtained βTl further. Theoretically, Tl and the thallium-containing slag metal Cd, Pb, Zn, Ni, Cu, Fe, Si is completely isolated. The experimental analysis of the degree of vacuum, quantity, distillation time, the distillation temperature purified thallium, experiments showed that the degree of vacuum and the distillation temperature is relatively large impact on the purification of thallium. Control of distillation temperature of 560 ° C the distillation time 40min, the degree of vacuum, 8-40Pa, with the quantity of 40-50g subjected to vacuum distillation, once evaporated substance in Cd, Tl content of 98.04%, 1.66%, respectively, almost all of Cd was evaporated Tl rarely is evaporated, the residue was 72.42% Tl. Take a residual matter 30 - 40 g, control the distillation temperature of 1012 ° C, the distillation time 50min, a degree of vacuum of 8-40Pa the secondary vacuum distillation, Tl content of secondary distilled off was 93.4%, quadratic residue Fe, Si, Ni, Cu, respectively, 0.11%, 0.0054%, 55.65%, 44.06%, which can be seen from experiments, Fe, Si, Ni, Cu is almost completely eliminated, while the Tl rarely stay in the quadratic residue, almost all was evaporated. Taking a second boil-Pb, Tl separation experiments available Tl purity of 99.0%. In summary, the experimental study of the papers for semi-industrial tests of the purification of thallium accumulated valuable raw data, and laid the foundation for the next semi-industrial tests, purified thallium theoretical analysis and experimental verification. , But also opened up a new process for a comprehensive recovery of thallium.
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