阅读说明：本技术 一种镍电解过程中抑制杂质铅、锌在阴极析出的方法 (Method for inhibiting impurities of lead and zinc from being separated out at cathode in nickel electrolysis process ) 是由 郑军福 冯建华 卢晓锋 周通 郭勇 苏兰伍 张峰瑞 李亦婧 张四增 宛顺磊 刘军 于 2020-05-20 设计创作，主要内容包括：本发明公开了一种镍电解过程中抑制杂质铅、锌在阴极析出的方法,包括以下步骤：(1)将镍电解液与氧化剂混合后搅拌5min～20min,得到混合液；镍电解液与氧化剂的体积比为1：(0.0001～0.001)；(2)以钛板为阴极、高冰镍板为阳极进行电解,同极间距为15～25cm,阳极液为镍电解液,阴极液为混合液,钛板位于装有混合液的隔膜袋中,阴极液与阳极液的液位差为2cm～4cm；隔膜袋中的混合液进行循环；隔膜袋中的温度为50℃～80℃；电解的工艺条件为：电流密度为200A/m<Sup>2</Sup>～250A/m<Sup>2</Sup>、通电时间为8h～48h。本发明效果好且操作简便。(The invention discloses a method for inhibiting impurities of lead and zinc from being separated out at a cathode in a nickel electrolysis process, which comprises the following steps: (1) mixing the nickel electrolyte and the oxidant, and stirring for 5-20 min to obtain a mixed solution; the volume ratio of the nickel electrolyte to the oxidant is 1: (0.0001 to 0.001); (2) electrolyzing by taking a titanium plate as a cathode and a high nickel matte plate as an anode, wherein the homopolar distance is 15-25 cm, anolyte is nickel electrolyte, catholyte is mixed liquid, the titanium plate is positioned in a diaphragm bag filled with the mixed liquid, and the liquid level difference between the catholyte and the anolyte is 2-4 cm; circulating the mixed liquid in the membrane bag; the temperature in the membrane bag is 50-80 ℃; the process conditions of electrolysis are as follows: the current density is 200A/m 2 ～250A/m 2 The electrifying time is 8-48 h. The invention has good effect and simple operation.)

1. A method for inhibiting impurities of lead and zinc from being separated out at a cathode in a nickel electrolysis process is characterized by comprising the following steps:

(1) mixing the nickel electrolyte and the oxidant, and stirring for 5-20 min to obtain a mixed solution; the volume ratio of the nickel electrolyte to the oxidant is 1: (0.0001 to 0.001);

(2) electrolyzing by taking a titanium plate as a cathode and a high nickel matte plate as an anode, wherein the homopolar distance is 15cm-25cm, anolyte is nickel electrolyte, catholyte is mixed liquid, the titanium plate is positioned in a diaphragm bag filled with the mixed liquid, and the liquid level difference between the catholyte and the anolyte is 2 cm-4 cm; the mixed liquid in the membrane bag circulates, and the circulation amount is 1m per minute³The volume of the mixed liquid of the diaphragm bag is 8L-12L; the temperature in the membrane bag is 50-80 ℃; the process conditions of electrolysis are as follows: the current density is 200A/m²～250A/m²The electrifying time is 8-48 h.

2. The method for inhibiting the separation of impurities of lead and zinc at the cathode in the nickel electrolysis process according to claim 1, wherein the pH of the nickel electrolyte is 4.5-5.0, and the nickel electrolyte comprises the following substances in concentration: 65g/L-75g/L of nickel ions, 0.0002g/L-0.0005g/L of zinc ions, 30g/L-35g/L of sodium ions and 0.0002g/L-0.0005g/L, H g/L of lead ions₃BO₃5g/L-10g/L, 55g/L-65g/L of chloride ions and 95g/L-105g/L of sulfate ions.

3. The method for inhibiting the separation of lead and zinc impurities at the cathode in the nickel electrolysis process according to claim 1, wherein the oxidant in the step (1) is sodium hypochlorite or hydrogen peroxide.

4. The method for inhibiting the separation of impurities of lead and zinc at the cathode in the nickel electrolysis process according to claim 3, wherein the effective chlorine concentration in the sodium hypochlorite is 5% -8%; the mass percentage concentration of the hydrogen peroxide is 25-30%.

Technical Field

The invention relates to the technical field of nickel electrolysis, in particular to a method for inhibiting impurities of lead and zinc from being separated out at a cathode in a nickel electrolysis process.

Background

The rapid development of high-temperature alloys for aeroengines and gas turbines and the national defense science and technology industry puts an urgent need for forming high-quality nickel products special for high-temperature alloys. The main production method of high-quality nickel product is electrolytic process, in which the content of lead and zinc elements is an important index for evaluating the quality of nickel product, and for reducing the content of lead and zinc in the nickel product the chemical purification or ion exchange resin method can be adopted, and the above-mentioned method can be adopted, and the equipment and position are required to be increased so as to greatly raise production cost.

Disclosure of Invention

The invention aims to provide a method for inhibiting the precipitation of impurities of lead and zinc on a cathode in a nickel electrolysis process, which has good effect and simple and convenient operation.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

a method for inhibiting impurities of lead and zinc from being separated out at a cathode in a nickel electrolysis process is characterized by comprising the following steps:

(1) mixing the nickel electrolyte and the oxidant, and stirring for 5-20 min to obtain a mixed solution; the volume ratio of the nickel electrolyte to the oxidant is 1: (0.0001 to 0.001);

(2) electrolyzing by taking a titanium plate as a cathode and a high nickel matte plate as an anode, wherein the homopolar distance is 15cm-25cm, anolyte is nickel electrolyte, catholyte is mixed liquid, the titanium plate is positioned in a diaphragm bag filled with the mixed liquid, and the liquid level difference between the catholyte and the anolyte is 2 cm-4 cm; the mixed liquid in the membrane bag circulates, and the circulation amount is 1m per minute³The volume of the mixed liquid of the diaphragm bag is 8L-12L; the temperature in the membrane bag is 50-80 ℃; the process conditions of electrolysis are as follows: the current density is 200A/m²～250A/m²The electrifying time is 8-48 h.

The method for inhibiting the impurities of lead and zinc from being precipitated at the cathode in the nickel electrolysis process is characterized in that the pH of the nickel electrolyte is 4.5-5.0, and the nickel electrolyte comprises the following substances in concentration: 65g/L-75g/L of nickel ions, 0.0002g/L-0.0005g/L of zinc ions, 30g/L-35g/L of sodium ions and 0.0002g/L-0.0005g/L, H g/L of lead ions₃BO₃5g/L-10g/L, 55g/L-65g/L of chloride ions and 95g/L-105g/L of sulfate ions.

The method for inhibiting the impurities of lead and zinc from being precipitated at the cathode in the nickel electrolysis process is characterized in that the oxidant in the step (1) is sodium hypochlorite or hydrogen peroxide.

According to the method for inhibiting the impurities of lead and zinc from being separated out at the cathode in the nickel electrolysis process, the method is characterized in that the effective chlorine concentration in the sodium hypochlorite is 5-8%; the mass percentage concentration of the hydrogen peroxide is 25-30%.

The invention has the beneficial technical effects that: the invention relates to a method for inhibiting reduction of lead and zinc ions as impurities on a cathode by adding an oxidant to change the oxidation-reduction atmosphere of electrode liquid. According to the invention, the oxidant is added into the catholyte in the electrolytic process, so that the contents of impurity elements of lead and zinc in the electrolytic nickel can be effectively reduced, and the quality of the electrolytic nickel product is effectively improved; the method is simple and convenient to operate, low in use cost and easy to realize in actual production.

Detailed Description

The invention discloses a method for inhibiting impurities of lead and zinc from being separated out at a cathode in a nickel electrolysis process, which comprises the following steps: (1) mixing the nickel electrolyte and the oxidant, and stirring for 5-20 min to obtain a mixed solution; the volume ratio of the nickel electrolyte to the oxidant is 1: (0.0001 to 0.001); the pH of the nickel electrolyte is 4.5-5.0, and the nickel electrolyte comprises the following substances in concentration: 65g/L-75g/L of nickel ions, 0.0002g/L-0.0005g/L of zinc ions, 30g/L-35g/L of sodium ions and 0.0002g/L-0.0005g/L, H g/L of lead ions₃BO₃5g/L-10g/L, 55g/L-65g/L of chloride ions and 95g/L-105g/L of sulfate ions. The oxidant is sodium hypochlorite or hydrogen peroxide. The concentration of the effective chlorine in the sodium hypochlorite is 5-8%; the mass percentage concentration of the hydrogen peroxide is 25-30%. (2) Electrolyzing by taking a titanium plate as a cathode and a high nickel matte plate as an anode, wherein the homopolar distance is 15-25 cm, anolyte is nickel electrolyte without adding an oxidant in the step (1), catholyte is mixed liquor, the cathode plate is placed in a diaphragm bag made of a polyester cotton canvas bag filled with the mixed liquor, and the catholyte and the anolyte keep a liquid level difference of 2-4 cm; the mixed liquid in the membrane bag circulates with the circulation amount of 8L/min/m³～12L/min/m³(volume of mixed solution flowing into a unit volume of membrane bag per unit time); the temperature in the membrane bag is 50-80 ℃; the process conditions of electrolysis are as follows: the current density is 200A/m²～250A/m²The electrifying time is 8-48 h. The nickel sheet is used as an oxidation group, and the content of lead and zinc is analyzed.

And simultaneously, carrying out a blank control test, under the condition that other conditions are not changed, using nickel electrolyte without adding an oxidant as catholyte, producing a blank sample nickel sheet, and analyzing the content of lead and zinc in the nickel sheet.

The production of electrolytic nickel is essentially an electrolytic cell reaction, Ni²⁺Electrons obtained on the surface of the cathode of the electrolytic cell are reduced into a nickel simple substance, and trace Pb contained in the mixed solution is reduced in the process²⁺、Zn²⁺Electrons obtained at the cathode are included in the nickel product in a simple substance form for stabilizing and controlling the qualityThe invention adds oxidants NaClO and H into the mixed solution to produce high-quality electrolytic nickel products₂O₂Because the standard electrode potential is more positive than that of lead and zinc, the lead and zinc ions are reduced preferentially at the cathode in the electrolytic cell, so that the reduction of impurities of lead and zinc ions is prevented; meanwhile, as the concentration of the main metal nickel ions is up to dozens of grams per liter, a small amount of oxidant can not influence the precipitation of nickel. The standard electrode potentials for each element are as follows:

Zn²⁺/Zn＝-0.763V

Pb²⁺/Pb＝-0.129V

Ni²⁺/Ni＝-0.23

ClO-/Cl₂＝1.63V,

H₂O₂/H₂O＝1.776V

the invention is further illustrated by the following specific examples.