Method for recovering selenium from high tellurium, silver and selenium slag through short process

Abstract

The invention discloses a method for recovering selenium from high tellurium, silver and selenium slag through a short process. The method comprises the following steps that S1, the high tellurium, silver and selenium slag is placed in a vacuum distillation furnace, vacuum distillation is carried out under the conditions of 20 Pa-100 Pa and 300 DEG C-350 DEG C for 2 h-3 h, and coarse selenium andbottom slag containing silver, copper and selenium are produced; and S2, the coarse selenium obtained in the step S1 is placed in a selenium oxidizing furnace, a reaction is made under the conditionsthat the oxygen flow rate is 6 m<3> / h-10 m<3> / h and the temperature is 500 DEG C-570 DEG C for 3 h, and selenium dioxide and bottom slag containing tellurium are obtained. Through a vacuum distillation method, the selenium is separated from the silver, the tellurium and the copper simply, quickly and efficiently in an energy-saving manner, the selenium can be purified, and the selenium dioxide isfinally obtained.

Description

technical field [0001] The invention relates to the technical field of recovery of smelting intermediate materials, in particular to a method for efficiently recovering valuable elements in a short flow of high tellurium silver selenium slag. Background technique [0002] During the pressure leaching process of copper anode slime, part of silver and selenium entered the solution, and sodium bisulfite was added to reduce silver ions and selenium ions to elemental silver and selenium by positive tetravalent sulfide ions, and then separated from the leaching solution in the form of precipitation. The precipitate was Silver selenium slag. Silver selenium slag contains about 80% selenium, and also contains valuable metals such as silver, copper, tellurium, etc., and has extremely high value. [0003] The composition of silver selenium slag is complex and difficult to handle. At present, it is mainly returned to the main process in the form of return material. Chinese patent CN1...

AI Technical Summary

Problems solved by technology

The above methods all refer to returning the silver-selenium slag to the Caldo furnace for re-smelting, but the products of the Caldo furnace have strict restrictions on the selenium content, and returning to the furnace not only affects the product quality of the Caldo furnace, but also prolongs the smelting time of the Caldo furnace and reduces the amount of heat produced by the Caldo furnace. production capacity

[0004] Selenium and tellurium belong to Group VI A of the periodic table of elements. Selenium is a non-metallic element in the fourth period, and tellurium is a non-metallic element in the fifth period. The properties of the two are similar. It is difficult to separate selenium and tellurium in high-tellurium silver selenium slag by conventional means, resulting in selenium, Tellurium Difficult to High Value Recycling

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