CN110812888A

CN110812888A - Method for removing silicon by nickel solution adsorption

Info

Publication number: CN110812888A
Application number: CN201911014207.3A
Authority: CN
Inventors: 王甲琴; 胡家彦; 李兰兰; 柴艮风; 王国超; 陈天翼; 王杰伟; 张明兰
Original assignee: Jinchuan Lanzhou Science And Technology Park Co Ltd; Jinchuan Group Co Ltd
Current assignee: Jinchuan Lanzhou Science And Technology Park Co Ltd; Jinchuan Group Co Ltd
Priority date: 2019-10-23
Filing date: 2019-10-23
Publication date: 2020-02-21

Abstract

The invention relates to a method for removing silicon by nickel solution adsorption, which adopts prefabricated colloidal nickel hydroxide precipitate as an adsorbent, adsorbs silica gel in the nickel solution under certain conditions, achieves the purpose of deep silicon removal after solid-liquid separation, reduces the silicon content in the nickel solution from about 1g/L to below 0.005g/L, and ensures that the yield of valuable metal nickel is above 99 percent. The method for deeply purifying and removing the silicon is simple and easy to implement, does not need to introduce other impurities, has high direct yield of valuable metals, is beneficial to the next procedure, and can realize industrialized continuous production.

Description

Method for removing silicon by nickel solution adsorption

Technical Field

The invention relates to the technical field of nickel production, and relates to a method for deeply removing silicon from a nickel solution by using a nickel hydroxide colloid.

Background

The nickel solution obtained in the nickel hydrometallurgy contains impurities such as cobalt, calcium, magnesium, lead, silicon and the like, and is used for preparing nickel plates and nickel salt crystals after the cobalt, calcium, magnesium and lead are subjected to targeted impurity removal by an extraction method and a precipitation method, but no corresponding treatment process is carried out on impurity silicon, and the silicon content in the system is maintained between 0.1 and 1 g/L. With the continuous application of nickel salt products in the anode materials of lithium ion batteries, the requirements on the impurity content of the nickel salt products are higher and higher, and particularly, the impurity silicon is inevitably introduced again in the production process, so the requirements on the silicon content in the raw materials are higher.

Regarding the research of the deep desiliconization method in the solution, the research mainly focuses on the desiliconization research of the sodium aluminate solution in the alumina production process, and the known Chinese patents are CN1569639, CN101857254, CN101891227A, CN102923745A, CN102951667A, CN103739010A and CN103803614A, and the method of removing the desiliconization in the sodium aluminate solution under normal pressure or pressure by using different desiliconization agents is mainly disclosed.

The Chinese patents CN1569639 and CN101857254 reduce the content of silicon dioxide in the sodium aluminate solution to about 1g/L by a method of crystal seed activation treatment or red mud addition. CN101891227A and CN103739010A Friedel salts (3 CaO. Al) prepared from wastes in alkali industry₂O₃·CaCl₂·10H₂O) or magnesium-aluminum hydrotalcite (Mg) prepared from bittern containing magnesium chloride₆Al₂(OH)₁₆CO₃·4H₂O) as desiliconizing agent, capable of removing at least 60% or 80% of the silica from the sodium aluminate solution, deeply desiliconizedAnd meanwhile, the reutilization of waste resources is realized. CN102923745A utilizes calcium oxide and EDTA to carry out pressurization to deeply remove silicon and iron in the sodium aluminate solution, so that the silicon concentration in the solution is lower than 0.67 mg/L. The iron concentration is less than 0.1 mg/L. CN102951667A adopts fly ash as desiliconization seed crystal, and adds the fly ash into sodium silicate solution to carry out desiliconization under normal pressure or medium pressure, the A/S in the sodium aluminate solution can be increased from 15-25 to 110-1000, and the fly ash separated after desiliconization can be used as raw material ingredient to produce alumina.

In addition, the method for desiliconizing in the high-silicon zinc sulfate solution is introduced in the national non-ferrous metals journal of "Vol.4 No.4, 1994, 38-40 by Mo Ding Cheng et al, iron and carbon powder are used for treating impurity silicon in the high-silicon acid solution, the test conditions are optimized, under the optimized test conditions, the silicon content is reduced to below 0.2g/L from about 23g/L, the desiliconization rate reaches above 99%, and the recovery rate of main metal zinc reaches about 98%. The principle is that by utilizing the electrochemical property of the system, the potential difference of about 1.2v is generated between iron and carbon particles in aqueous solution, which is favorable for the deposition of colloidal silica, and in addition, the iron reacts with acid under the acidic condition to generate Fe²⁺And Fe³⁺Fe (OH) formed when the pH is raised₂And Fe (OH)₃Simultaneously, the adsorption and bonding bridging functions are exerted, and the generated silica gel is condensed to achieve the aim of desilication.

The silicon removal method in the patent and the article mainly aims at removing impurity silicon in high-silicon solution of other systems, and a deep silicon removal method in nickel solution is not reported, the silicon content in the solution after impurity removal by the method is still more than 0.2g/L, and the method can not achieve the purpose of deep silicon removal; meanwhile, in the impurity removal process, the silicon removal agent is added to introduce other impurity ions into the solution, so that the impurity removal burden of the subsequent process is increased.

Disclosure of Invention

In order to avoid the defects in the silicon removal method and solve the problem of deep silicon removal in the nickel solution, the invention provides a method for removing silicon by nickel solution adsorption. The invention utilizes the characteristics of silica gel, adopts nickel hydroxide colloid as an adsorbent, adsorbs the silica gel in a nickel solution by nickel hydroxide precipitation at a certain temperature, and achieves the purpose of deep silica removal after solid-liquid separation after stable adsorption, and the specific contents are as follows: a, preparation of an adsorbent: preparing the pure nickel sulfate crystal into a nickel solution with the concentration of 20-25 g/L, heating to 50-80 ℃, adding a sodium hydroxide solution to precipitate a nickel hydroxide colloid, wherein the concentration of the added sodium hydroxide solution is 100-400 g/L, and performing solid-liquid separation to obtain the nickel hydroxide colloid;

heating the solution B: putting the nickel-rich solution into a container, and heating to 50-80 ℃; the solution rich in nickel is nickel sulfate, nickel chloride, a mixed solution of nickel sulfate and nickel chloride, a nickel-cobalt sulfate solution, a mixed solution of nickel-cobalt sulfate and nickel chloride, the total concentration of nickel is 15 g/L-150 g/L, and the content of silicon is 0.01 g/L-1 g/L;

c, adsorption and silicon removal: after the temperature of the solution reaches a preset value, adding a proper amount of nickel hydroxide colloid prepared in the step A for precipitation, and continuously stirring for a period of time, wherein the stirring time is 1-10 hours;

d, separating reactants: and D, performing solid-liquid separation on the substance subjected to the operation in the step C to obtain a purified nickel solution and a nickel hydroxide colloidal precipitate.

It is preferable that: and D, performing solid-liquid separation in the step A and the step D by adopting suction filtration separation or filter pressing separation.

Further, the method comprises the following steps: and D, reusing the nickel hydroxide colloidal precipitate obtained in the step D in the step C, wherein the nickel hydroxide colloidal precipitate can be continuously used for 3-4 times.

The invention has the beneficial effects that: the process is simple, the impurity removal effect is good, the silicon content of the nickel solution after impurity removal and purification is less than 0.005g/L, the silicon removal rate is greater than 95%, the nickel yield is greater than 99%, and the problem of deep silicon removal in the nickel solution is solved. No other impurities are introduced in the process of removing silicon, the direct yield of valuable metals is high, the pH of the solution after impurity removal is stable, the next procedure is facilitated, and the industrial continuous production can be realized.

Drawings

FIG. 1 is a block diagram of the process flow of the present invention.

Detailed Description

Example 1

Weighing 5g of sodium hydroxide, adding 20mL of water to prepare a 250g/L sodium hydroxide solution, preparing a 25g/L nickel sulfate solution by using a nickel sulfate crystal (with the purity of 99%), heating 300mL of the nickel sulfate solution to 50 ℃, adding the prepared sodium hydroxide solution while stirring, stirring for reacting for 2 hours, carrying out vacuum filtration, and washing the nickel hydroxide colloidal precipitate after solid-liquid separation for 2-3 times by using hot pure water. And taking 1L of silicon-containing nickel sulfate solution, heating to 50 ℃, adding the nickel hydroxide colloid for precipitation while stirring, stirring for reaction for 2 hours, carrying out reduced pressure suction filtration, and washing filter residue obtained after solid-liquid separation with hot pure water for 2-3 times. The solution indexes before and after silicon removal are compared in table 1. The yield of nickel was calculated from the volume of the solution before and after the removal of silicon and the nickel content in the solution to be 99.21%.

TABLE 1 comparison of solution indexes before and after desiliconization of nickel sulfate solution

Example 2

Weighing 8g of sodium hydroxide, adding 20mL of water to prepare a 400g/L sodium hydroxide solution, preparing a 20g/L nickel sulfate solution by using a nickel sulfate crystal, heating 600mL of the nickel sulfate solution to 80 ℃, adding the prepared sodium hydroxide solution while stirring, stirring for reacting for 2 hours, carrying out reduced pressure suction filtration, and washing a nickel hydroxide colloidal precipitate after solid-liquid separation for 2-3 times by using hot pure water. Taking 2L of silicon-containing nickel chloride solution, heating to 80 ℃, adding the nickel hydroxide colloid for precipitation while stirring, performing vacuum filtration after stirring reaction for 3 hours, and washing filter residue after solid-liquid separation with hot pure water for 2-3 times. The comparison of the indexes of the solution before and after silicon removal is shown in Table 2, when the reaction temperature is higher, the concentration of nickel in the solution after silicon removal is increased due to evaporation and concentration of the solution, and the yield of nickel is calculated to be 99.13% according to the volume of the solution before and after silicon removal and the content of nickel in the solution.

TABLE 2 comparison of solution indexes before and after desiliconization of nickel chloride nickel solution

Example 3

Weighing 150g of sodium hydroxide, adding 375mL of water to prepare a 400g/L sodium hydroxide solution, preparing a 25g/L nickel solution by using nickel sulfate crystals, heating 9L of the nickel sulfate solution to 70 ℃, adding the prepared sodium hydroxide solution while stirring, stirring for reacting for 2 hours, carrying out reduced pressure suction filtration, and washing the nickel hydroxide colloidal precipitate after solid-liquid separation for 2-3 times by using hot pure water. Taking 70L of silicon-containing nickel cobalt sulfate solution, heating to 70 ℃, adding the prepared sodium hydroxide solution while stirring, stirring for reaction for 5 hours, performing pressure filtration, and washing filter residue after solid-liquid separation for 2-3 times by using hot pure water. The comparison of the indexes of the solution before and after silicon removal is shown in Table 3, when the reaction temperature is higher, the concentration of nickel in the solution after silicon removal is increased due to evaporation and concentration of the solution, and the yield of nickel is 99.46% and the direct yield of cobalt is 99.37% calculated by the volume of the solution before and after silicon removal and the contents of nickel and cobalt in the solution.

TABLE 3 comparison of solution indexes before and after desiliconization of nickel sulfate solution

As can be seen from the above examples, the content of impurity silicon in various nickel solutions can be reduced from about 1g/L to less than 0.005g/L by the method of the invention, the yield of valuable metals is more than 99%, and the purpose of deep silicon removal is achieved.

Claims

1. A method for removing silicon by nickel solution adsorption is characterized in that: the method comprises the following process steps:

a, preparation of an adsorbent: preparing the pure nickel sulfate crystal into a nickel solution with the concentration of 20-25 g/L, heating to 50-80 ℃, adding a sodium hydroxide solution to precipitate a nickel hydroxide colloid, wherein the concentration of the added sodium hydroxide solution is 100-400 g/L, and performing solid-liquid separation to obtain the nickel hydroxide colloid;

2. The method for removing silicon by adsorption of nickel solution as claimed in claim 1, wherein: and D, performing solid-liquid separation in the step A by adopting suction filtration separation or filter pressing separation.

3. The method for removing silicon by adsorption of nickel solution as claimed in claim 1, wherein: and D, carrying out solid-liquid separation by adopting suction filtration separation or filter pressing separation.

4. The method for removing silicon by adsorption of nickel solution as claimed in claim 1, wherein: and D, reusing the nickel hydroxide colloidal precipitate obtained in the step D in the step C, wherein the nickel hydroxide colloidal precipitate can be continuously used for 3-4 times.