Copper electrolyte purifying technology

Abstract

The invention discloses a copper electrolyte purifying technology which comprises the following steps: adding a crystallizing agent into copper electrolyte or pre-decoppering post-liquid or adding a crystallizing agent into copper electrolyte after adsorption impurity removal treatment or pre-decoppering post-liquid; crystallizing to obtain copper-nickel compound salt; and separating and recycling copper and nickel from the obtained copper-nickel compound salt to realize purification of the copper electrolyte, wherein in the adsorption impurity removal treatment, an oxide of antimony and / or bismuth and the hydrate thereof are adopted as adsorbents to selectively adsorb the impurities As, Sb and Bi in the copper electrolyte, and the generation of black copper sludge, black copper plates and AsH3 gas can be thoroughly eliminated in a copper electrolyte purifying process. The technology disclosed by the invention has the advantages of simple process, simplicity and convenience in operation, low cost, high efficiency, good operation environment and the like, and is suitable for the industrial production of copper electrolyte purification.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy, and in particular relates to a copper electrolyte purification process, which is suitable for the separation of impurities such as arsenic, antimony, bismuth and nickel in the copper electrolyte. Background technique [0002] In the copper electrolytic scouring process, impurities such as arsenic, antimony, bismuth and nickel in the anode copper are electrochemically dissolved together with the copper into the electrolyte. These impurities exhibit different behaviors during electrorefining and are classified according to their electrochemical order and their solubility in the electrolyte as follows: [0003] The first type of impurities include zinc, iron, nickel, lead, tin, etc. They are more electronegative than copper and thus dissolve electrochemically at the anode. Among them, lead and tin form a sulfate that is insoluble in the electrolyte——PbSO 4 and Sn(OH) 2 SO 4 , the content of these...

AI Technical Summary

Problems solved by technology

There are many defects in the traditional copper electrolyte purification process using electrowinning to remove impurities As, Sb, and Bi: the effective utilization rate of electricity in the electrowinning process is very low, generally less than 20%; the energy consumption is high, and the purification of 1m 3 The electrolyte consumes 100-120kwh of electricity and 0.8-1 ton of steam; the operating environment of the clean liquid is poor, producing a large amount of black copper sludge and black copper plates, and releasing harmful gas AsH 3 ; The direct recovery rate of copper is low, and the black copper sludge and black copper plate produced need to be returned to the fire process system to recycle the copper, causing copper and impurities arsenic, antimony, and bismuth to circulate in the smelting system

However, these methods can only be used to remove impurities such as arsenic, antimony, and bismuth, but cannot remove impurities such as nickel and iron.

Therefore, these methods can only be used as a supplement to electrowinning copper removal and impurity removal, and cannot completely replace the traditional copper electrolyte purification process.

Another reason why these methods cannot replace the traditional process of copper electrolyte purification is that the separation of copper and nickel in the electrolyte can only rely on electrowinning.

[0009] The separation and recovery of nickel in the purification process of copper electrolyte is not only because the recovery of nickel has certain economic value, but more importantly, with the increase of Ni concentration, the resistance of the electrolyte increases, and the unit power consumption of the copper electrolytic refining process increases

The forced freezing and crystallization of the liquid after the second decopper removal can separate some impurities such as nickel and iron, but the separation efficiency is not high. Generally, the crystallization of nickel is less than 60%. 24h, the liquid still contains 15-20g / L Ni after crystallization

In short, the traditional purification process of copper electrolyte has defects such as low purification efficiency, high production cost, and poor working environment.

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