Wet process refining technology for purifying selenium

Abstract

The invention discloses a wet process refining technology for purifying selenium. The wet process refining technology for purifying selenium mainly comprises the steps that firstly, NaOH is added into alloy blowing tower absorption liquid to remove part of base metal, and activated carbon is used for adsorption, filtering and purification; secondly, thiourea and HCI are sequentially used for deep impurity reduction, and a pure selenous acid solution is obtained through filtering; thirdly, sulfur dioxide is used for reduction, and fine selenium powder with high purity is obtained. As a single wet process refining technology, compared with a traditional technology, the wet process refining technology for purifying selenium has the advantages of being short in process, easy to implement, low in labor intensity, small in energy consumption, low in production cost, short in production cycle, good in operation environment, free of generation of middle overstock materials and the like; the tower absorption liquid obtained through alloy blowing absorption is subjected to three times of purification, impurity removing and filtering, and the fine selenium powder with the grade up to 99.1% can be obtained as long as sulfur dioxide is introduced for reduction, the direct yield is increased to 83.5% from original 79.8%, the production cycle is shortened to 3 d from original 7 d, the processing cost can be reduced to 13 yuan / kg, and good popularization value and economic benefits are achieved.

Description

technical field [0001] The invention belongs to the technical field of rare metal metallurgy, and in particular relates to a wet refining process for purifying selenium from an absorption liquid of an alloy blowing tower. Background technique [0002] At home and abroad, after pressurized leaching of copper anode slime, the pressurized leached slag enters the alloy blowing process for blowing, and is absorbed by the power wave recovery system and press-filtered to form a tower absorption liquid, which contains a certain amount of selenium. form into the solution, and then reduced to crude selenium by sulfur dioxide. The dried crude selenium is oxidized and absorbed by an oxidation furnace in the refining process to form a selenous acid solution. That is to say, the copper anode slime has to go through the process of pressure leaching (wet)-alloy blowing (fire)-absorption reduction (wet)-oxidation absorption (fire)-sulfur dioxide reduction (wet) and other processes to obtain ...

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Problems solved by technology

[0003] There are problems in the original process: 1. The process flow is long, and the yield of selenium is low

Especially fire method is bigger to selenium loss, directly affects the yield of selenium; 2. adopt oxygen oxidation method, consume a large amount of electric energy, cause production cost height; Selenium dioxide leads to poor operating environment and greater harm to personnel; 4. The process flow is complicated, the production cycle is long, and the intermediate materials are overstocked, which is not conducive to the realization of materials; 5. The crude selenium produced by the alloy blowing furnace must be processed After washing and drying, it can enter the oxidation furnace for oxidation and absorption. There are problems such as large water consumption, large amount of waste water, high maintenance rate of special equipment oxidation furnace, and high labor intensity for post employees.

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