Resource utilization method for iron-rich electrolytic manganese residues

Abstract

The invention discloses a method for resource utilization of iron-rich electrolytic manganese residues. The method mainly comprises the following steps that the iron-rich electrolytic manganese residues are placed in an anode chamber of an electrolytic cell, then water, concentrated sulfuric acid and reduced iron powder are added into the anode chamber according to a set proportion, the anode and the cathode are separated through an acid and alkali resistant filter cloth diaphragm, a cathode electrolytic iron product is collected after the electrolytic reaction is finished, electrolyte is recycled, and leaching residues are used for preparing microcrystalline glass; doping the leaching residues into a silicate material, an alkaline calcium-based material and aluminum oxide powder, carrying out ball milling, uniformly mixing, adding an adhesive, and carrying out compression molding; and sintering and cooling the pressed and molded blank to obtain a glass ceramic product. According to the method, the iron-rich electrolytic manganese residues serve as the raw material, the purity of the cathode electrolytic iron obtained through ore pulp electrolysis method recovery can reach 98% or above, and a glass ceramic product prepared from the leaching residues meets the JCT 872-2019 standard. Compared with the prior art, the method has the advantages that the resource utilization rate of the iron-rich electrolytic manganese residues is high, the operation process is simple, the treatment cost is low, and the market prospect is good.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy and inorganic non-metallic materials, and in particular to a method for resource utilization of iron-rich electrolytic manganese slag. Background Art

[0002] Manganese is one of my country's important strategic resources, and it is said that "no manganese, no steel". At present, manganese metal is mainly produced by electrolysis. The production of electrolytic manganese metal is a typical hydrometallurgical process, and iron-rich electrolytic manganese slag is the iron removal waste slag produced in the leaching process of manganese ore. At present, every ton of electrolytic manganese metal produced will produce 2 to 5 tons of iron-rich electrolytic manganese slag. The annual production of iron-rich electrolytic manganese slag in my country is about 150,000 tons. Compared with traditional electrolytic manganese slag, iron-rich electrolytic manganese slag has a higher moisture content and is more harmful to the environment. The existing method for treating iron-rich electrolytic manganese slag is mainly the stockpiling method. The stockpiling of slag not only damages the ecological environment, but also wastes a large amount of heavy metal resources such as iron and manganese contained in the iron-rich electrolytic manganese slag. For this reason, it is urgent to solve the problem of treatment and disposal of iron-rich electrolytic manganese slag. Using iron-rich electrolytic manganese slag as raw material, and preparing microcrystalline glass from its leached slag after iron extraction by slurry electrolysis is a feasible resource treatment method.

[0003] Slurry electrolysis is a hydrometallurgical process that has been developed for more than 30 years. It integrates leaching, solution purification and electrolysis. The anode leaches the ore while the cathode electrodeposits the metal. It converts the high-energy-consuming anode or cathode reaction into an efficient process of leaching metal from the slurry, reducing the voltage and power consumption of the electrolytic cell. The use of slurry electrolysis to extract iron from iron-rich electrolytic manganese slag simplifies the hydrometallurgical process. Microcrystalline glass is a new material composed of glass phase and crystal phase. It has the characteristics of glass and ceramics, and is also called glass ceramics. Microcrystalline glass has the advantages of high bending and compressive strength, low water absorption, high Mohs hardness and good wear resistance, and can be used in the building decoration industry. This type of microcrystalline glass has low requirements for raw materials. It is mainly made of various industrial waste slags as raw materials, supplemented by some auxiliary raw materials. It can absorb a large amount of solid waste without generating too much secondary pollution. It is currently a well-deserved "green and environmentally friendly building material".

[0004] At present, the slurry electrolysis method can realize the recovery of iron in solid waste as elemental iron. For example, patent CN 202211444063.7 provides a method and device for recovering iron from red mud. The invention first mineralizes the red mud slurry, and then sends the mineralized slurry into the electrolysis system for electrolysis to obtain a high-purity iron product. In addition, ordinary electrolytic manganese slag can be used to prepare microcrystalline glass. For example, patent CN 201810088487.1 provides a microcrystalline glass prepared by electrolytic manganese slag and its preparation method. It uses electrolytic manganese slag, phosphate rock, granite, silica lime, fly ash, mica, carbon, borax, magnesite, heavy calcium and zirconium oxide as raw materials in parts by weight. The mixed raw materials are first melted into glass liquid, and then the glass plate is crystallized at a lower temperature to make a microcrystalline glass sample. A large number of studies have shown that a small amount of iron components in the raw materials for preparing microcrystalline glass can reduce the crystallization temperature of microcrystalline glass, but too high an iron content will lead to a decrease in the microhardness and flexural resistance of the microcrystalline glass product.

[0005] To this end, the problems of high iron content, low resource utilization rate, and low product added value in iron-rich electrolytic manganese slag are addressed. The present invention proposes to first use slurry electrolysis to extract iron from iron-rich electrolytic manganese slag, obtain high-value-added high-purity electrolytic iron powder at the cathode, and the slurry electrolyte can be recycled; secondly, the leached slag remaining after slurry electrolysis is mixed with auxiliary raw materials by direct sintering to successfully prepare microcrystalline glass. Compared with existing traditional technologies, the present invention realizes the comprehensive high-value utilization of iron-rich electrolytic manganese slag, with a simple overall operation process, low cost, and considerable economic benefits. Summary of the invention

[0006] In view of the above problems, the main purpose of the present invention is to use an iron-rich electrolytic manganese slag with a relatively rich iron content as a raw material to prepare microcrystalline glass after extracting iron through slurry electrolysis.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is a method for resource utilization of iron-rich electrolytic manganese slag, and the specific steps are as follows: (1) The present invention uses slurry electrolysis to extract iron from iron-rich electrolytic manganese slag to obtain electrolytic iron powder with high purity, and the leached slag is mixed with auxiliary raw materials and directly sintered to prepare high-value-added architectural microcrystalline glass, and the above process is convenient, simple, environmentally friendly and safe. (2) The present invention can fully tap the utilization value of iron-rich electrolytic manganese slag, expand the road for resource treatment of iron-rich electrolytic manganese slag, and has considerable economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Attached Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0009] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0010] Embodiment 1:

[0011] Take 5 kg of crushed iron-rich electrolytic manganese slag and place it in the anode chamber of the electrolytic reactor, and separate the positive and negative electrodes with a double-layer acid-alkali resistant filter cloth diaphragm. Add 25 L of water at a solid-liquid ratio of 1:5, add 1.5 L of 98% concentrated sulfuric acid to the anode chamber and stir, and add 0.5 kg of reduced iron powder to the ore slurry in the anode chamber as the electrolyte. Use a stainless steel plate as the cathode plate and a ruthenium-plated titanium plate as the anode plate. Turn on the power supply and the constant current density is 30 mA / cm 2 , the mass of electrolytic iron powder precipitated on the cathode plate after electrolysis at 25 ℃ for 12 hours was 1.64 kg, and the leached residue was mixed with auxiliary materials to prepare microcrystalline glass. The dried cathode product and anode residue were completely digested, and the iron concentration in the digestion solution of the cathode product and anode residue and the electrolyte was measured. The calculation showed that the iron leaching rate was 80%, the iron recovery rate could reach more than 70%, the current efficiency exceeded 70%, and the iron purity exceeded 98%.

[0012] According to the mass percentage, 70% leached slag, 20% waste glass, 5% calcined raw material, and 5% alumina were weighed and sent to the mixing ball mill according to the ball-to-material ratio of 5:1. The ball-milled mixture was passed through a 100-mesh screen, and the fine powder after sieving was evenly spread in the mold with adhesive. The powder tablet press was used to press and form at a pressure of 10 MPa for 60 s. The formed blank was sent to a high-temperature resistance furnace, heated to 800 ℃ at a heating rate of 10 ℃ / min and kept warm for 120 min, and the microcrystalline glass sample was obtained after cooling with the furnace. The physical phase analysis, flexural properties and acid and alkali resistance tests were carried out. The main crystal phase of the microcrystalline glass was calcium feldspar, the flexural strength was 34.6 MPa, the acid resistance was 0.17%, and the alkali resistance was 0.07%. The product meets the JCT872-2019 standard for microcrystalline glass for architectural decoration.

[0013] Embodiment 2:

[0014] The iron extraction step is the same as in Example 1. Example 2 for preparing microcrystalline glass is as follows: 60% leached slag, 30% waste glass, 5% calcined raw material, and 5% alumina are weighed by mass percentage, and sent into a mixing ball mill to mix evenly according to a ball-to-material ratio of 5:1; the ball-milled mixture is passed through a 100-mesh sieve, and the fine powder after sieving is added with an adhesive and evenly spread in a mold, and a powder tablet press is used to press and form at a pressure of 10 MPa for 60 s; the formed blank is sent into a high-temperature resistance furnace, heated to 900°C at a heating rate of 10°C / min and kept warm for 120 min, and the microcrystalline glass sample is obtained after cooling with the furnace. The product was subjected to phase analysis, flexural properties and acid and alkali resistance tests. The main crystal phase of the microcrystalline glass was found to be calcium feldspar, with a flexural strength of 56.7 MPa, an acid resistance of 0.16%, and an alkali resistance of 0.07%. The product complies with the JCT 872-2019 standard for microcrystalline glass for architectural decoration.

[0015] Embodiment 3: The iron extraction step is the same as in Example 1. Example 3 for preparing microcrystalline glass is as follows: 60% leaching slag, 30% waste glass, 5% calcined raw material, and 5% alumina are weighed by mass percentage, and sent into a mixing ball mill to mix evenly according to a ball-to-material ratio of 5:1; the ball-milled mixture is passed through a 100-mesh sieve, and the fine powder after sieving is added with an adhesive and evenly spread in a mold, and a powder tablet press is used to press and form at a pressure of 10 MPa for 60 s; the formed blank is sent into a high-temperature resistance furnace, heated to 1000°C at a heating rate of 10°C / min and kept warm for 120 min, and the microcrystalline glass sample is obtained after cooling with the furnace. The physical phase analysis, flexural properties and acid and alkali resistance tests were carried out on it. The main crystal phase of the measured microcrystalline glass is diopside, the secondary crystal phase is calcium feldspar, the flexural strength is 83.2 MPa, the acid resistance is 0.13%, and the alkali resistance is 0.06%. The product meets the JCT 872-2019 standard for microcrystalline glass for architectural decoration.

[0016] Through specific embodiments, it can be concluded that: by adopting the method for resource utilization of iron-rich electrolytic manganese slag proposed in the present invention, iron is extracted from the iron-rich electrolytic manganese slag by slurry electrolysis, the leaching rate of Fe in the iron-rich electrolytic manganese slag can reach more than 80%, the Fe recovery rate can reach more than 70%, and the obtained Fe purity exceeds 98%; the microcrystalline glass prepared from the leached slag has good physical and chemical properties and meets the JCT 872-2019 microcrystalline glass standard for architectural decoration.

[0017] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for resource utilization of iron-rich electrolytic manganese slag, characterized in that: The method comprises the following steps: the iron-rich electrolytic manganese slag just discharged from the workshop is crushed and transported to the anode chamber of the electrolytic reactor, a certain proportion of water, concentrated sulfuric acid and reduced iron powder are added to the anode chamber, the mixture is fully stirred and mixed at a certain temperature, and the positive and negative electrodes are connected to the power supply for electrolysis. After the electrolysis is completed at a constant current density, the elemental iron precipitated on the cathode plate is collected. The electrolyte and the leached slag are separated into solid and liquid by a plate and frame filter press, and the electrolyte is recycled as the leaching liquid of the next batch of iron-rich electrolytic manganese slag. After the leached slag is dried, silicate materials, alumina and alkaline calcium-based materials are added and ball-milled to mix uniformly; the uniformly mixed materials are added with an adhesive, pressed into a blank, and then placed in a high-temperature resistance furnace for heat treatment. After the heat treatment is completed, the furnace is cooled to obtain microcrystalline glass, and the obtained microcrystalline glass samples are subjected to performance testing.

2. A method for resource utilization of iron-rich electrolytic manganese slag according to claim 1, characterized in that: In the process of slurry electrolysis iron extraction, the anode plate uses a precious metal-plated plate, wherein the precious metal-plated plate includes but is not limited to a titanium-plated plate, a ruthenium-plated plate, a tin-plated plate, etc.; the cathode plate uses a stainless steel plate; the mass ratio of concentrated sulfuric acid to iron-rich electrolytic manganese slag is 1:3-8; the mass ratio of reduced iron powder to iron-rich electrolytic manganese slag is 1:5-15; the set current density is 10-60 mA / cm 2 ; Temperature is 20~60℃; Electrolysis time is 4~48 hours.

3. A method for resource utilization of iron-rich electrolytic manganese slag according to claim 1, characterized in that: The leached residue is mixed with silicate materials, alumina and alkaline calcium-based materials to prepare microcrystalline glass, and the mass percentage of the raw materials is: 35-75% of leached residue, 30-70% of silicate materials, 5-10% of alumina, and 5-10% of alkaline calcium-based materials. Among them, the silicate materials include but are not limited to one or more of waste glass, kaolin, feldspar minerals, etc.; the alkaline calcium-based materials include but are not limited to one or more of burnt raw materials, quicklime, carbide slag, etc.

4. A method for resource utilization of iron-rich electrolytic manganese slag according to claim 1, characterized in that: The leached residue is mixed with silicate materials, alumina and alkaline calcium-based materials for ball milling with a ball-to-material ratio of 3:1 to 10:1; the ball milling time is 30 min to 180 min.

5. A method for resource utilization of iron-rich electrolytic manganese slag according to claim 1, characterized in that: The particle size range of the fine powder of the mixed material after ball milling is 60~300 mesh.

6. A method for resource utilization of iron-rich electrolytic manganese slag according to claim 1, characterized in that: The adhesive is a 5% to 20% aqueous solution of an adhesive material, and the adhesive material includes but is not limited to PVA polyvinyl alcohol, resin, etc.; 0.03 to 0.5 g of the adhesive is added to each gram of the mixed fine powder, and the pressure of the mixed fine powder being pressed into a green embryo is 10 MPa to 80 MPa.

7. A method for resource utilization of iron-rich electrolytic manganese slag according to claim 1, characterized in that: The pressed green embryo is placed in a high-temperature resistance furnace, heated to 800-1600°C at a heating rate of 3-20°C / min, and kept at this temperature for 30-240 min.

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