A process for producing cathode copper by electrolytic refining of low-grade copper anode plates

Abstract

The present invention discloses a process for producing cathode copper by electrolytic refining of low-grade copper anode plates. The process comprises the following steps: the electrolyte composition used in the electrolytic refining is: 2 SO 4 190-200 g / L; Ni 2+ ≤15g / L; As≤15g / L; Cu 2+ 42-46g / L; the additives are ADT, gelatin, thiourea and hydrochloric acid, the amount of ADT added is 10-15g / t.Cu, the amount of gelatin added is 20-30g / t.Cu; the amount of thiourea added is 50-60g / t.Cu, the amount of hydrochloric acid added is 200-300ml / t.Cu, the electrolyte temperature is 62-64°C, and the single tank circulation volume is 30-35L / min. tank. The process control of the present invention is stable, the product quality rate is high, the goal of process adaptation to raw materials is achieved, and good conditions are created for broadening the procurement channels of copper raw materials and reducing costs and increasing efficiency of enterprises.

Description

Technical Field

[0001] The invention belongs to the field of cathode copper production and relates to a process for producing cathode copper by electrolytic refining of low-grade anode plates. Background Art

[0002] The electrolytic refining process of low-impurity, high-grade anode plates is very mature, and the requirements for the main electrolytic process technical conditions such as electrolyte copper content, electrolyte nickel content, electrolyte arsenic content, single tank circulation volume, temperature, etc. are not high. The additive system consists of three additives: gelatin, thiourea, and hydrochloric acid. Under low-impurity conditions, 7-degree gelatin can fully meet the quality control needs of cathode copper.

[0003] With the increasingly tight supply of copper raw materials and the complexity of the raw material composition structure, the supply of low-grade, high-impurity copper concentrate and crude copper has now become normalized. Under the current pyrometallurgical smelting process, the produced anode plates have the characteristics of high arsenic content, high nickel content and low copper content. The original electrolytic process technical conditions and additive system under low-impurity conditions are no longer suitable for the treatment of such anode plates, and it is impossible to guarantee the production of qualified cathode copper with good physical appearance and chemical composition. Summary of the invention

[0004] The purpose of the present invention is to address the problem that the electrolytic process technical conditions and additive system under the above-mentioned low-impurity raw material conditions cannot meet the electrolytic refining treatment of high-arsenic, high-nickel and low-copper anode plates, and to propose a process with strong pertinence, stable process control and high product quality rate.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A process for producing cathode copper by electrolytic refining of low-grade copper anode plates, the main electrolytic process technical conditions and unique additive system include:

[0007] 1. In order to enhance the conductivity of the electrolyte and reduce the cell voltage, the acid content of the electrolyte is controlled at 190-200g / L; due to the high dissolution rate of nickel, in order to reduce the viscosity of the electrolyte, the nickel content of the electrolyte is controlled at ≤15g / L; in order to reduce the amount of floating anode mud, the arsenic content of the electrolyte is controlled at ≤15g / L.

[0008] 2. Since the copper anode plate contains arsenic ≥0.3%, nickel ≥0.3%, and copper <99%, copper ions will inevitably become depleted after entering the electrolysis tank. In order to ensure the quality of cathode copper precipitation, it is necessary to dissolve crystalline copper sulfate to make new solution or add high copper solution (such as copper stripping solution) to supplement copper. According to production practice, the copper content of the electrolyte needs to be controlled at 42-46g / L.

[0009] 3. In view of the low copper content of copper anode plates, in order to reduce concentration polarization, the upper limit of the single-cell circulation volume is controlled (30-35L / min. cell).

[0010] 4. In order to accelerate the migration rate of copper ions and enable the additives to fully play their role, and ensure the production of cathode copper with good physical appearance and chemical quality, the electrolyte temperature is controlled at 62-64°C.

[0011] 5. Additive system:

[0012] (1) Since copper anode plates contain high arsenic and nickel, the anode mud rate is high and the anode mud output is large during electrolytic refining. In order to flocculate and settle the anode mud in time and ensure the quality of the cathode copper produced is good, the additive ADT is added. However, the amount of ADT added should not be too much. According to production practice, the amount of ADT added is 10-15g / t.Cu.

[0013] (2) Because 12-degree gelatin has a large molecular weight and a stronger action than 7-degree gelatin, it is better to select 12-degree gelatin to inhibit the formation of granulation on the cathode copper surface in view of the characteristics of high arsenic, high nickel and low copper anode plates. According to production practice, the addition amount of 12-degree gelatin is 20-30g / t.Cu.

[0014] (3) The amount of thiourea added is 50-60g / t.Cu. At the same time, through field practice, for this kind of high arsenic, high nickel, low copper anode plate, in order to ensure the good quality of the cathode copper produced, the ratio of thiourea added to gelatin added needs to be controlled at 1.5:1-3:1.

[0015] (4) Hydrochloric acid is used as an auxiliary additive. On the one hand, it refines the plate surface. On the other hand, it combines with silver ions in the electrolyte to form silver chloride precipitation, which enters the anode mud to reduce the silver content in the cathode copper. According to production practice, the amount of hydrochloric acid added is 200-300ml / t.Cu.

[0016] The beneficial effects of the present invention are as follows: the optimal main electrolytic process technical conditions are determined for the electrolytic treatment of anode plates with high arsenic content, high nickel content and low copper content; suitable additive formulas, the amounts of various additives added and the core urea-gel ratio are provided for the electrolytic treatment of anode plates with high arsenic content, high nickel content and low copper content; the process control is stable, the product quality rate is high and the technical and economic indicators are excellent. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with specific embodiments.

[0018] Example 1

[0019] A process for producing cathode copper by electrolytic refining of low-grade copper anode plates, wherein the electrolyte composition used in the electrolytic refining is: H2SO4: 190g / L; Ni 2+ :10g / L;As:10g / L;Cu 2+: 42g / L; the additives are ADT, gelatin, thiourea and hydrochloric acid, the amount of ADT added is 10g / t.Cu, the amount of 12-degree gelatin added is 20g / t.Cu; the amount of thiourea added is 60g / t.Cu, the amount of hydrochloric acid added is 200ml / t.Cu, and the ratio of thiourea to 12-degree gelatin added is 2.5:1.

[0020] The electrolyte temperature is 62°C, the current density is 270A / m 2 , the cell voltage of the electrolytic cell is: 0.28V, the center distance of the same pole is: 105mm, and the circulation volume of a single cell is 30L / min.

[0021] The specifications of the high-arsenic, high-nickel, and low-copper anode plates are 1000×960×48mm, the weight is 375kg / piece, and the chemical composition is (see Table 1).

[0022] Table 1 Chemical composition of anode plate (%)

[0023] Cu As As Sb The S O 98.83 0.32 0.34 0.053 0.017 0.0093 0.14

[0024] The composition of the cathode copper obtained after electrolysis is:

[0025] Table 2 Chemical composition of cathode copper (%)

[0026] This Whereas The Cr Mn Sb Cd As P 0.000045 0.000045 0.000072 0.00009 0.000072 0.000072 0.000054 0.00018 0.0001 Pb S Sn As Fe If Zn Co Ag 0.00009 0.00036 0.00009 0.00009 0.00011 0.0006 0.00009 0.00009 0.001

[0027] Example 2

[0028] A process for producing cathode copper by electrolytic refining of low-grade copper anode plates, wherein the electrolyte composition used in the electrolytic refining is: H2SO4: 195g / L; Ni 2+ :12g / L;As:13g / L;Cu 2+ : 44g / L; the additives are ADT, gelatin, thiourea and hydrochloric acid, the amount of ADT added is 12g / t.Cu, the amount of 12-degree gelatin added is 30g / t.Cu; the amount of thiourea added is 50g / t.Cu, the amount of hydrochloric acid added is 250ml / t.Cu, and the ratio of thiourea to 12-degree gelatin added is 1.67:1.

[0029] The electrolyte temperature is 63°C, the current density is 275A / m 2 , cell voltage of the electrolytic cell: 0.30V, center distance of the same pole: 105mm, single cell circulation volume is 30L / min.

[0030] The specifications of the high-arsenic, high-nickel, and low-copper anode plates are 1000×960×48mm, the weight is 375kg / piece, and the chemical composition is (see Table 3).

[0031] Table 3 Chemical composition of anode plate (%)

[0032] Cu() As(%) As() Sb() The(%) S(％) O(％) 98.8 0.35 0.34 0.06 0.016 0.0044 0.11

[0033] The composition of the cathode copper obtained after electrolysis is:

[0034] Table 4 Chemical composition of cathode copper (%)

[0035]

[0036] Example 3

[0037] A process for producing cathode copper by electrolytic refining of low-grade copper anode plates, wherein the electrolyte composition used in the electrolytic refining is: H2SO4: 200g / L; Ni 2+ :14g / L;As:14g / L;Cu 2+ : 46g / L; the additives are ADT, gelatin, thiourea and hydrochloric acid, the amount of ADT added is 15g / t.Cu, the amount of 12-degree gelatin added is 25g / t.Cu; the amount of thiourea added is 55g / t.Cu, the amount of hydrochloric acid added is 300ml / t.Cu, and the ratio of thiourea to 12-degree gelatin added is 2.2:1.

[0038] The electrolyte temperature is 64°C, the current density is 300A / m 2 , cell voltage of the electrolytic cell: 0.31V, center distance of the same pole: 105mm, single cell circulation volume is 35L / min. cell.

[0039] The specifications of the high-arsenic, high-nickel, and low-copper anode plates are 1000×960×48mm, the weight is 375kg / piece, and the chemical composition is (see Table 5).

[0040] Table 5 Chemical composition of anode plate (%)

[0041] Cu() As(%) As() Sb() The(%) S(％) O(％) 98.6 0.45 0.40 0.055 0.017 0.01 0.10

[0042] The composition of the cathode copper obtained after electrolysis is:

[0043] Table 6 Chemical composition of cathode copper (%)

[0044]

Claims

1. A process for producing cathode copper by electrolytic refining of low-grade copper anode plates, characterized in that: The low-grade copper anode plate contains arsenic ≥ 0.3% and nickel ≥ 0.3%; the electrolyte composition used in the electrolytic refining is: H2SO4 is 190-200g / L; Ni 2+ ≤15g / L; As≤15g / L; Cu 2+ 42-46g / L; the additives are ADT, gelatin, thiourea and hydrochloric acid, the amount of ADT added is 10-15g / t.Cu, the amount of gelatin added is 20-30g / t.Cu; the amount of thiourea added is 50-60g / t.Cu, the amount of hydrochloric acid added is 200-300ml / t.Cu, the electrolyte temperature is 62-64°C, and the single tank circulation volume is 30-35L / min; The ratio of the added amount of thiourea to gelatin is (1.5:1)-(3:1); The gelatin used is 12 degree gelatin.

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