Method for deeply removing arsenic and mercury in crude selenium

A crude selenium and removal technology is applied in the directions of element selenium/tellurium, process efficiency improvement, chemical industry, etc., can solve the problems of insignificant mercury removal effect and low mercury content, etc., and achieves the effects of low cost and simple process flow

Pending Publication Date: 2021-10-26
KUNMING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The selenium products produced by these methods belong to industrial-grade crude selenium, and the mercury content in the processed raw materials is low, and the mercury removal effect is not obvious

Method used

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  • Method for deeply removing arsenic and mercury in crude selenium

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Weigh 200g of crude selenium whose main components are Se 96%, As 0.42%, and Hg 0.33%, put it on the stainless steel screen with an aperture of 500 mesh, put a receiving crucible under the screen, and put them together in the reaction kettle for heating and melting , after the temperature in the reactor reaches 250°C, that is, after the thick selenium inside is melted, vacuumize under the reactor, take it out after 30 minutes of heat preservation, and obtain 164.5g of selenium melt in the receiving basin; put the obtained selenium melt into the Vacuum distillation was carried out in a vacuum furnace with a vacuum degree of 1 Pa, a temperature of 270° C., and a heat preservation of 2 hours to finally obtain 162.9 g of selenium.

[0022] ICP-AES was used to quantitatively analyze the chemical composition of impurity elements arsenic and mercury. The content of arsenic and mercury in selenium products was 3.75ppm and 287ppm respectively, and the removal rates reached 99.91%...

Embodiment 2

[0024] Weigh 200g of crude selenium whose main components are Se 96%, As 0.42%, and Hg 0.33%, put it on the stainless steel screen with an aperture of 1000 mesh, put a receiving crucible under the screen, and put them together in the reaction kettle for heating and melting , after the temperature in the reactor reaches 350°C, that is, after the thick selenium in the inside melts, vacuumize under the reactor, take it out after 30 minutes of heat preservation, and obtain 159.7g of selenium melt in the receiving basin; then put the obtained selenium melt into Vacuum distillation was carried out in a vacuum furnace with a vacuum degree of 30 Pa and a temperature of 400° C. for 2 hours to obtain 157.6 g of selenium.

[0025] ICP-AES was used to quantitatively analyze the chemical composition of impurity elements arsenic and mercury. The content of arsenic and mercury in selenium products was 4.23ppm and 275ppm respectively, and the removal rates reached 99.90% and 91.67% respectivel...

Embodiment 3

[0027] Take by weighing the thick selenium 200g that main component is Se 96%, As 0.42%, Hg 0.33%, be placed on the stainless steel screen cloth of 1500 meshes of aperture, put one deck screen cloth again below the screen cloth, then put a receiving crucible below, will They are put together in the reaction kettle and heated and melted. After the temperature in the reaction kettle reaches 500°C, that is, after the crude selenium inside is melted, vacuumize under the reaction kettle, take it out after keeping warm for 30min, and obtain 156.8g of selenium melt in the receiving basin ; Then the obtained selenium melt was placed in a vacuum furnace for vacuum distillation, the vacuum degree was 10Pa, the temperature was 500° C., and the temperature was kept for 2 hours, and finally 154.2 g of selenium was obtained.

[0028] ICP-AES was used to quantitatively analyze the chemical composition of impurity elements arsenic and mercury. The content of arsenic and mercury in selenium pro...

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Abstract

The invention discloses a method for deeply removing arsenic and mercury in crude selenium, which belongs to the technical field of purification of scattered metals. As arsenic and mercury are easy to volatilize together with selenium through distillation, and impurities arsenic and mercury in selenium are relatively complex in components and partially exist in the form of compounds, and are difficult to deeply remove through simple filtration. The method comprises the following steps of melting a crude selenium raw material in a reaction kettle, carrying out suction filtration under a negative pressure condition to realize separation of a main element selenium from large-particle arsenic and mercury so as to obtain a selenium melt with relatively high purity, carrying out vacuum distillation on the collected selenium melt or a condensed selenium ingot in a vacuum furnace, volatilizing and condensing selenium in a steam form, thereby realizing further separation of the main elements selenium, arsenic and mercury, deeply removing arsenic and mercury in the crude selenium slag, and well realizing recycling of hazardous wastes.

Description

technical field [0001] The invention belongs to the technical field of purification of scattered metals, and in particular relates to a method for deeply removing arsenic and mercury in crude selenium. Background technique [0002] Selenium is a sparse metal with an abundance in the Earth's crust of only 5×10 -6 %, and exists in a dispersed state. Selenium is widely used in materials, metallurgy, chemical industry, agriculture, medical treatment and other fields. With the development of semiconductors, solar cells, thermoelectric materials and the rise of selenium-rich agriculture, the demand for selenium is increasing day by day. Selenium has become a support for high-tech development and new materials. key materials for development. In recent years, with the different sources of coarse selenium residues, selenium residues high in arsenic and mercury are more common, and their treatment is more complicated. Both arsenic and mercury are highly toxic substances, listed as h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B19/02C22B30/04C22B43/00
CPCC01B19/02C22B30/04C22B43/00C01P2006/80Y02P10/20Y02P20/10
Inventor 徐宝强刘浪杨斌蒋文龙罗欢甄甜甜查国正李一夫田阳刘大春王飞吴鉴曲涛杨佳孔令鑫孔祥峰
Owner KUNMING UNIV OF SCI & TECH
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