METHOD FOR SEPARATING TELLURIUM AND SELENIUM AND METHOD FOR MANUFACTURING TELLURIUM USING SAME

摘要

The present invention relates to a method for separating tellurium (Te) and selenium (Se) from a tellurium-dissolved solution such as waste thermoelectric materials by using neutral extractant such as TBP and TEHP solely or combined. Tellurium and selenium can be separated very efficiently and economically compared with a traditional method as the recovery rate of tellurium equal to or greater than 97% and a separation coefficient equal to or greater than 400 can be achieved if tellurium and selenium are separated from a dissolved solution in which Bi_2Te_3-based waste thermoelectric materials are dissolved, by the method according to the present invention. In addition, the present invention can mitigate the problem of environmental pollution greatly compared with a traditional method conducted in a strongly acid solution as separation extraction is conducted in a weak acid atmosphere with pH ranging from 1.0 to 1.5. The method for separating tellurium and selenium comprises the steps of: manufacturing a dissolved solution of materials including tellurium and selenium by dissolving the materials in a solution including strong acid; manufacturing a pretreatment solution by adding base to the dissolved solution to adjust the pH of the dissolved solution to range from 1.0 to 1.5; manufacturing a complex compound solution by making the pretreatment solution include oxalate ions (C_2O_4^2-) and making the tellurium ions and selenium ions, which exist in the pretreatment solution, react with oxalate ions respectively to form a complex compound; and obtaining a first extraction solution manufactured by selectively moving the complex compound of tellurium oxalate, which exists in the complex compound solution in an aqueous solution phase, to the neutral extractant in an organic phase via a solvent extraction method using the neutral extractant.;COPYRIGHT KIPO 2015