A formulation, preparation method and application of a choline compound in electrolytic manganese

Abstract

This invention discloses a formulation, preparation method, and application of choline compounds in electrolytic manganese. Choline is used as an additive, and divalent manganese ion salts, ammonium salts, and the additives are dissolved in a solvent to form an electrolyte. The electrolyte is introduced into an electrolytic cell, the pH value is adjusted, and inert electrodes are used as the cathode and anode. Electrolysis is performed by setting the voltage, current, and temperature of the electrolytic cell, yielding high-purity metallic manganese. This invention has the technical advantages of high-purity metallic manganese, high current efficiency, and no environmental pollution.

Description

Technical Field

[0001] This invention belongs to the field of metallurgy, specifically relating to the formulation, preparation method and application of choline compounds in electrolytic manganese. Background Technology

[0002] Manganese metal has a wide range of applications. In the steel industry, manganese consumption is second only to iron, with 90% of manganese used in the steel industry and 10% used in non-ferrous metallurgy, chemicals, electronics, batteries, and agriculture. my country has relatively abundant manganese ore resources with large reserves, mainly distributed in Guangxi, Hunan, Chongqing, and Guizhou. Among them, the proven manganese ore reserves in Tongren, Guizhou are approximately 700 million tons. Due to overcapacity and economic conditions, product prices have continued to decline. High-purity manganese can be widely used in magnetic materials, battery materials, and sputtering targets. With the technological advancement of the metallurgical industry, new trends in metallurgical manganese use have placed special demands on the refinement and diversification of high-purity manganese. The demand for special metallic manganese in the non-ferrous metallurgical industry is constantly increasing. Therefore, developing high-value-added high-purity manganese is particularly important.

[0003] The existing process for producing metallic manganese mainly involves: grinding manganese carbonate ore—leaching manganese ore powder—sulfidation for impurity removal—electrolysis in an electrolytic cell—artificial passivation, washing, and drying—product stripping—packaging. This process suffers from the following problems leading to low purity of metallic manganese: ① During the impurity removal process, sodium dimethyl dithiocarbamate (SMDC) is added to remove metal ions from the solution. SMDC is a water-soluble substance with the chemical formula C3H6NS2Na. It is relatively stable in alkaline media but easily decomposes under acidic and high-temperature conditions, generating extremely fine colloidal particles such as CS2 that are suspended in the manganese sulfate solution. During electrolysis, these particles are adsorbed and encapsulated by the metallic manganese, causing excessive levels of C and S in the product; ② The electrolysis process uses a stainless steel plate as the cathode and a lead-tin-antimony-silver quaternary alloy as the anode, inevitably leading to excessive levels of Fe and Pb; ③ The sulfuric acid produced at the anode during electrolysis easily returns to the electrolysis system, resulting in a low pH value, hydrogen evolution reaction, and the re-dissolution of metallic manganese, severely reducing current efficiency and increasing energy consumption.

[0004] Furthermore, during the electrolysis process, the addition of SeO2 triggers a series of hydrolysis reactions. SeO2 can promote the manganese electrolysis reaction and inhibit the hydrogen evolution reaction. However, the hydrolysis of SeO2 in the electrolyte, and its dissolution, raises the following issues: ① According to international research on the toxicity and toxicology of selenium, excessive selenium intake in humans can lead to selenium poisoning, manifesting as fatigue, vomiting, irritability, hair loss, nail loss, nervous system damage, cirrhosis, pulmonary edema, weakened coordination, paralysis, and other neurological disorders, even death in severe cases. For other organisms in nature, excessive selenium intake can cause neurological disorders; fish and waterfowl in aquatic environments may exhibit deformities or even death. ② Selenium dioxide can form selenium precipitates during electrolysis, clogging the diaphragm and affecting process operation. ③ Selenium dioxide is reduced at the cathode, forming an alloy with manganese and entering the product, affecting product purity. ④ Some selenium residue remains in the wastewater, anode mud, and manganese slag from manganese electrolysis, causing environmental pollution.

[0005] Patent application CN 113293408 A discloses a method for electrolytically depositing high-purity manganese from a manganese chloride electrowinning solution. The method involves preparing a manganese chloride solution, adding colloidal sulfur (at a mass-volume concentration of 10-14 g / L), and thoroughly mixing the solution at room temperature. The pH of the solution is then adjusted to 5.0 with ammonia to obtain the electrowinning solution. This solution is then poured into an electrowinning tank, and the tank temperature, cathode and anode current densities, and electrowinning voltage are adjusted. Electrowinning is carried out for 24 hours to obtain high-purity manganese with a purity of 99.99-99.999%. This technology uses high-purity manganese chloride and high-purity ammonium chloride as raw materials to prepare a solution, adding colloidal sulfur as an additive or a composite additive mainly composed of colloidal sulfur. This replaces the traditional method of adding toxic selenium dioxide or sulfur dioxide to the manganese electrowinning solution, producing high-purity manganese with a purity of 99.99-99.999%. The process is short, easy to operate, environmentally friendly, and meets the requirements of clean production. This technology incorporates a large amount of colloidal sulfur, with a mass-volume concentration of 10-14 g / L. This colloidal sulfur reduces the purity of metallic manganese. The patent discloses a purity of 99.99-99.999%. However, the colloidal sulfur is insoluble in water and remains suspended. This technology has limited practical application in industrial production due to its complex operation and excessive colloidal sulfur content, resulting in metallic manganese products that do not meet the requirements of the industry standard YB / T051-2015 for electrolytic manganese. Summary of the Invention

[0006] The purpose of this invention is to provide a formulation, preparation method and application of choline compounds in electrolytic manganese, and to prepare high-purity metallic manganese by using choline compounds as additives.

[0007] The technical solution of this invention. A formulation for a choline compound in electrolytic manganese, wherein the electrolyte for electrolytic manganese includes a choline compound.

[0008] The above-mentioned formulation of choline compounds in electrolytic manganese, wherein the choline compounds are choline, choline sulfate, choline chloride, or choline hydroxide.

[0009] The above-mentioned formulation of choline compounds in electrolytic manganese, wherein the electrolyte comprises a solvent, a divalent manganese ion salt, an ammonium salt, and a choline compound.

[0010] In the above-mentioned formulation of choline compounds in electrolytic manganese, the divalent manganese ions are manganese chloride or manganese sulfate, the purity of manganese chloride or manganese sulfate is above 99.7%, the manganese ion concentration is 1-50 g / L, and the solvent is deionized water or ethylene glycol.

[0011] In the above-mentioned formulation of choline compounds in electrolytic manganese, the ammonium salt is ammonium sulfate or ammonium chloride, with a concentration of 20-140 g / L.

[0012] The above-mentioned formulation of choline compounds in electrolytic manganese, wherein the concentration of the choline compounds is 0.01-0.1 g / L.

[0013] A method for preparing choline compounds in electrolytic manganese includes the following steps:

[0014] Step 1: Prepare the electrolyte by dissolving divalent manganese salt, ammonium salt, and choline compound in a solvent;

[0015] Step 2: Pour the electrolyte prepared in Step 1 into the electrolytic cell, adjust the pH value, and use inert electrodes as the cathode and anode.

[0016] Step 3: Electrolyze in an electrolytic cell to obtain high-purity metallic manganese.

[0017] In the above-mentioned method for preparing choline compounds in electrolytic manganese, step 2 involves adjusting the pH value to 5.5-8.5 with ammonia.

[0018] In the above-mentioned method for preparing choline compounds in electrolytic manganese, the inert electrode is made of gold, platinum, ruthenium, ruthenium-coated titanium, or stainless steel as the cathode, and graphite or lead alloy as the anode, with a cathode-cathode distance of 20-50 mm.

[0019] The above-mentioned method for preparing choline compounds in electrolytic manganese involves an electrolysis temperature of 40-60℃, a voltage of 0.1-10V, and a cathode current density of 200-500A / m. 2 .

[0020] The application of choline compounds in electrolytic manganese, where choline compounds are used as additives in the electrolyte of electrolytic manganese.

[0021] The above-mentioned choline compounds are used in the electrolysis of metallic manganese, wherein the choline compounds contain a choline structure. Compounds.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0023] ①In the process for preparing high-purity manganese in this invention, divalent manganese ion salts, ammonium salts, and salts containing choline structures are used. A mixed solution of compounds and alcohols serves as the electrolyte. Choline-structured compounds are used in the electrolysis of high-purity manganese, but this technology is not yet publicly available. Studies have found that choline-structured compounds have a wide electrochemical window, broad solubility range, and good pH stability, without increasing impurities in the electrolyzed manganese. However, choline-structured compound electrolytes have a neutral pH, while colloidal sulfur electrolytes have a weakly acidic pH. Using colloidal sulfur as an additive in electrolyte preparation requires the addition of sodium citrate solution, polyacrylamide solution, ascorbic acid solution, and boric acid solution, which not only increases production costs but also complicates the production process. Furthermore, colloidal sulfur is insoluble in water and suspends in it, limiting its practical application in industrial production and making the process complex.

[0024] ② The inert electrode materials are gold, platinum, ruthenium, graphite and ruthenium-coated titanium electrodes, which avoids the electrode materials carrying impurities into the electrolysis system, thus preventing the low purity of metallic manganese and improving the purity of metallic manganese.

[0025] ③ The choline structure has certain catalytic activity and plays a certain catalytic role in the deposition of metallic manganese.

[0026] ④ Furthermore, the choline structure has good thermal stability, the ionic liquid is not easily volatile, its saturated vapor pressure is almost zero, and it will not pollute the environment during use.

[0027] ⑤ Choline has high electrical conductivity and large heat capacity, making it easier to control the temperature during electrolysis. Detailed Implementation

[0028] The present invention will be further described below with reference to embodiments and comparative examples, but these are not intended to limit the present invention.

[0029] Example

[0030] A formulation for the use of a choline compound in electrolytic manganese, wherein the electrolyte for electrolytic manganese includes the choline compound.

[0031] Furthermore, the choline compound is choline, choline sulfate, choline chloride, or choline hydroxide.

[0032] Furthermore, the electrolyte is a solvent, a divalent manganese ion salt, an ammonium salt, and a choline compound.

[0033] Furthermore, the divalent manganese ions are manganese chloride or manganese sulfate, the purity of manganese chloride or manganese sulfate is above 99.7%, the manganese ion concentration is 1-50 g / L, and the solvent is deionized water or ethylene glycol.

[0034] Furthermore, the ammonium salt is ammonium sulfate or ammonium chloride, with a concentration of 20-140 g / L.

[0035] Furthermore, the concentration of the choline compound is 0.01-0.1 g / L.

[0036] A method for preparing choline compounds in electrolytic manganese includes the following steps:

[0037] Step 1: Prepare the electrolyte by dissolving divalent manganese salt, ammonium salt, and choline compound in a solvent;

[0038] Step 2: Pour the electrolyte prepared in Step 1 into the electrolytic cell, adjust the pH value, and use inert electrodes as the cathode and anode.

[0039] Step 3: Electrolyze in an electrolytic cell to obtain high-purity metallic manganese.

[0040] Furthermore, in step 2, the pH value is adjusted to 5.5-8.5 using ammonia.

[0041] Furthermore, the inert electrode uses gold, platinum, ruthenium, ruthenium-coated titanium electrode or stainless steel as the cathode, and graphite or lead alloy as the anode, with a cathode-cathode distance of 20-50 mm.

[0042] Furthermore, the electrolysis temperature is 40-60℃, the voltage is 0.1-10V, and the cathode current density is 200-500A / m. 2 .

[0043] The application of choline compounds in electrolytic manganese, where choline compounds are used as additives in the electrolyte of electrolytic manganese.

[0044] The above-mentioned choline compounds are used in the electrolysis of metallic manganese, wherein the choline compounds contain a choline structure. Compounds.

[0045] The technology of the present invention will be further illustrated below with specific examples.

[0046] Example 1

[0047] A mixed aqueous solution containing 35 g / L manganese sulfate, 100 g / L ammonium sulfate, and 0.03 g / L choline sulfate was prepared using deionized water as the solvent. The pH was adjusted to 7.2 with ammonia. A graphite electrode was used as the anode, and a ruthenium-coated titanium electrode was used as the cathode, with a cathode-cathode spacing of 35 mm, a cell voltage of 4.3 V, and a cathode current density of 360 A / m. 2 At a temperature of 40℃, electrolysis for 24 hours yielded metallic manganese with a purity of 99.992% and a current efficiency of 68%.

[0048] Example 2

[0049] A mixed aqueous solution containing 50 g / L manganese chloride, 100 g / L ammonium chloride, and 0.04 g / L choline chloride was prepared using deionized water as the solvent. The pH was adjusted to 7.5 with ammonia. A graphite electrode was used as the anode, and a ruthenium-coated titanium electrode was used as the cathode, with a cathode-cathode spacing of 45 mm, a cell voltage of 4.5 V, and a cathode current density of 350 A / m. 2 At a temperature of 40℃, electrolysis for 24 hours yielded metallic manganese with a purity of 99.993% and a current efficiency of 70%.

[0050] Example 3

[0051] A mixed solution containing 50 g / L manganese sulfate, 120 g / L ammonium sulfate, and 0.02 g / L choline was prepared using ethylene glycol as the solvent. A graphite electrode was used as the anode, and a ruthenium-coated titanium electrode as the cathode, with a cathode-cathode spacing of 35 mm, a cell voltage of 4.5 V, and a cathode current density of 330 A / m. 2 At a temperature of 45℃, electrolysis was carried out for 36 hours to obtain metallic manganese with a purity of 99.995% and a current efficiency of 72%.

[0052] Example 4

[0053] A mixed aqueous solution containing 50 g / L manganese chloride, 100 g / L ammonium chloride, and 0.05 g / L choline chloride was prepared using ethylene glycol as the solvent. The pH was adjusted to 7.5 with ammonia. A graphite electrode was used as the anode, and a ruthenium-coated titanium electrode was used as the cathode, with a cathode-cathode spacing of 55 mm, a cell voltage of 4.2 V, and a cathode current density of 330 A / m. 2 At a temperature of 45℃, electrolysis was carried out for 36 hours to obtain metallic manganese with a purity of 99.995% and a current efficiency of 74%.

[0054] Example 5

[0055] A mixed aqueous solution containing 50 g / L manganese chloride, 100 g / L ammonium chloride, and 0.05 g / L choline chloride was prepared using ethylene glycol as the solvent. The pH was adjusted to 7.5 with ammonia. A graphite electrode was used as the anode, a platinum electrode as the cathode, the anode-cathode distance was 55 mm, the cell voltage was 5 V, and the cathode current density was 330 A / m. 2 At a temperature of 50℃, electrolysis was carried out for 36 hours to obtain metallic manganese with a purity of 99.994% and a current efficiency of 75%.

[0056] Example 6

[0057] A mixed aqueous solution containing 35 g / L manganese sulfate, 100 g / L ammonium sulfate, and 0.03 g / L choline hydroxide was prepared using deionized water as the solvent. The pH was adjusted to 7.5 with ammonia. A graphite electrode was used as the anode, and a ruthenium-coated titanium electrode was used as the cathode, with a cathode-cathode spacing of 40 mm, a cell voltage of 4.4 V, and a cathode current density of 360 A / m. 2 At a temperature of 40℃, electrolysis for 24 hours yielded metallic manganese with a purity of 99.995% and a current efficiency of 72%.

Claims

1. An electrolyte for electrolysis of manganese by a choline compound, characterized by, The electrolyte is deionized water, manganese chloride, ammonium chloride and choline chloride; the purity of the manganese chloride is more than 99.7%, the manganese ion concentration is 1-50 g / L; the ammonium chloride concentration is 20-140 g / L; and the choline chloride concentration is 0.01-0.1 g / L.

2. The method of using choline compounds in the electrolyte of electrolytic manganese according to claim 1, characterized in that, The method comprises the following steps: step 1, preparing an electrolyte by dissolving a divalent manganese ion salt, an ammonium salt and a choline compound in a solvent, wherein the divalent manganese ion salt is manganese chloride, the ammonium salt is ammonium chloride, and the choline compound is choline chloride; Step 2, introducing the electrolyte prepared in step 1 into an electrolytic cell, adjusting the pH value, and using inert electrodes as the cathode and the anode; Step 3, performing electrolysis in the electrolytic cell to obtain high-purity metallic manganese; In step 2, the pH value is adjusted to 5.5-8.5 by using ammonia water; The inert electrodes are gold, platinum, ruthenium, a ruthenium-coated titanium electrode or stainless steel as the cathode, and graphite or lead alloy as the anode, and the distance between the cathode and the anode is 20-50 mm. The electrolysis temperature is 40-60°C, the voltage is 0.1-10V, and the current density of the cathode is 200-500A / m 2 .