Production practice of short process 4N tellurium

Laboratory and industrial experiments indicated that the pickling process and the improved oxidizing acid leaching process could effectively remove impurities and obtain pure tellurium dioxide. The loss of tellurium could be effectively reduced, and its extraction rate could be improved by controlling the terminal potential of the oxidative acid leaching. The solution composition of tellurium dioxide produced by the new process oxidative acid leaching was basically the same as that of the calcined one made in the workshop. After boiling, washing and casting, 4N(99.99%) tellurium ingots were prepared. The new process has improved production efficiency, and processing 1 ton of reduced tellurium slag can save 4 807.8 yuan in cost.