Impurity removing refining process of high pure bismuth

Abstract

This invention relates to an electrolysis technique of ore magma of fluorosilicic acid of bismuth mine. Bismuth concentrate is used as raw material of ore magma to enter into slurry tank, after slurry and add chlorhydric acid to adjust acid, the above-mentioned serofluid is consecutively added into electrolyte tank of ore magma, extraction and electroextraction of bismuth are completed simultaneously by effect that electrolyte tank is imported direct current, cathode that has electrolysed scorifys bismuth powder falling on bottom of membrane bag with sponginess, spongio-bismuth is pressed into pressure filter of spongio-bismuth by equipment of drawing powder and spongio-bismuth is pressed to be block and dewatered, smelted to metallic crude bismuth, hypso-pure bismuth of which the final content is 99.999% is epurated by importing chlorine gas, natrium hydroxydatum to eliminate miscellaneous object.

Description

technical field [0001] The invention relates to a process for removing impurities and refining high-purity bismuth, and belongs to the technical field of pyrometallurgy of nonferrous metals. Background technique [0002] Bismuth is in group 5 of the periodic table, its chemical atomic weight is 208.9804, and the outer electron is 6S 2 6P 3 , usually shown as +3 valence and +5 valence, and in a few cases it is shown as +2 valence, +1 valence, -3 valence and -1 valence; metal bismuth is a silver-gray shiny solid, brittle, easy to break, and hard. The specific gravity is 9.78, soluble in dilute HNO 3 , hot H 2 SO 4 and concentrated hydrochloric acid. [0003] Bismuth is a rare metal with very little stock in nature. Most of it coexists with lead, tungsten and molybdenum deposits, and it has no mining value itself. In industry, it is mainly recovered from the by-products of lead-zinc mines and copper mines, and bismuth can also be recovered from tin mines. The crude bismu...

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Problems solved by technology

[0007] This method has following shortcoming in practice: (1), above-mentioned reaction is gas-liquid reaction, and its speed of reaction is restricted by the contact area of ​​chlorine gas and bismuth liquid, therefore, the impurity removal time is longer, especially in the lead removal later stage, lead is in Concentration reduction and diffusion speed slow down in the bismuth liquid, which is not conducive to removing impurities as soon as possible; (2), impurities such as chlorine remain after the bismuth liquid is refined and need further alkaline refining to obtain qualified products; (3) Passing chlorine gas for a long time at high temperature will seriously corrode the equipment and pollute the environment; (4), the refining slag contains high bismuth, and the later stage slag often reaches 3 to 5% bismuth, which obviously reduces the recovery and recovery rate of bismuth refining

However, the operation process needs to be heated for a long time and the chlorine gas is introduced twice, polluting the environment, and the problems of high energy consumption have not been well resolved.

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