Gradient utilization method of industrial waste residues based on red mud and nickel sulfate residues

Abstract

The invention discloses a gradient utilization method of industrial waste residue based on red mud and nickel sulfate slag, which comprises the following steps: S1, respectively taking 1: 1-2.5 parts by mass of nickel sulfate slag and red mud mixture, and uniformly stirring to obtain a mixture a; s2, adjusting the pH value of the mixture a to 6.5-7.5; and S3, taking a plurality of groups of the mixture a after the pH value is adjusted, and respectively adding different auxiliary materials to prepare and generate the aerated concrete block, the road red mud roadbed material and the building ceramsite. The invention provides a gradient utilization method of industrial waste residues based on red mud and nickel sulfate slag, which utilizes the nature of the nickel sulfate slag and high-content Si and Ca components of the nickel sulfate slag to naturally neutralize the alkalinity of the red mud, improve the ratio of Si to Ca of the red mud and enhance the activity of the red mud, and other auxiliary materials are added to prepare aerated concrete blocks, light ceramsite, road red mud base materials and improved soil. The industrial waste is converted into various building material resources, the utilization rate of the red mud and the nickel sulfate slag is increased, and the industrialization degree of comprehensive utilization of the industrial waste is improved.

Description

Technical Field

[0001] The invention relates to the technical field of environmental protection chemical industry, and in particular to a cascade utilization method of industrial waste residue based on red mud and nickel sulfate residue. Background Art

[0002] Red mud is a solid waste produced in the process of producing alumina from bauxite. It has a fine average particle size, and its chemical composition mainly includes Al2O3, Fe2O3, SiO2, CaO, etc. It has a high alkali content and a pH value of 10.5-12.0. Under natural conditions, red mud has low strength and poor water stability. According to the difference in bauxite grade and different process methods for producing alumina, 0.8-1.6 tons of red mud will be produced for every ton of alumina produced. For the disposal of red mud, the main method used at home and abroad is to pile up and cover the soil, which not only occupies a large amount of land, but also harms the environment due to its high alkalinity and dust. Since 2019, my country has produced 100 million tons of red mud each year, and the cumulative stockpile of red mud has exceeded 800 million tons. At present, the comprehensive utilization rate of red mud in my country is only about 4%, especially for red mud as a building material resource. A lot of research and practical utilization have been carried out. However, due to the failure to properly solve the problems of low activity and high alkalinity of red mud, most red mud building materials cannot be effectively utilized; and the cost of extracting valuable metals such as iron and titanium from red mud is too high, resulting in poor economic feasibility.

[0003] At the same time, nickel is an important material for alloys and new energy, and its smelting is divided into pyrometallurgy and hydrometallurgy. Laterite nickel ore is one of the main minerals for nickel smelting and relies on imports. In hydrometallurgy, sulfuric acid (or hydrochloric acid) is often used to acid-leach laterite nickel ore, and the insoluble matter after acid leaching is solid waste. At present, my country's hydrometallurgy mainly uses sulfuric acid produced by copper smelting and imported laterite nickel for acid leaching. The solid waste after acid leaching of sulfuric acid and laterite nickel ore is commonly known as "nickel sulfate slag". Nickel sulfate slag has a low pH value and is acidic. The main components are SiO2, Ca, Al2O3, Fe2O3, etc. Calculated on a dry basis, the SiO2 content reaches 30% to 70%, and Fe, Mg, Al, Ca and other components account for 20% to 40%. Sulfuric acid hydrometallurgy of nickel will produce a large amount of nickel sulfate slag. For every ton of nickel sulfate produced, about 20 tons of nickel sulfate slag will be produced. At present, the domestic nickel sulfate slag is also stored and disposed of, which consumes a large area of ​​land, is costly, and seriously harms the surrounding environment. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a cascade utilization method of industrial waste residue based on red mud and nickel sulfate slag.

[0005] The present invention adopts the following technical solutions:

[0006] A cascade utilization method for industrial waste residue based on red mud and nickel sulfate residue comprises the following steps:

[0007] S1. Take a mixture of nickel sulfate slag and red mud in a ratio of 1:1 to 2.5 parts by mass, stir evenly, and obtain a mixture a;

[0008] S2, adjusting the pH value of the mixture a to 6.5-7.5;

[0009] S3, taking several groups of mixtures a after adjusting the pH, adding different auxiliary materials respectively, and preparing aerated concrete blocks, road red mud subgrade materials and building ceramsite.

[0010] Preferably, the method for preparing the aerated concrete block in step S3 is specifically as follows:

[0011] A1. Take 30% to 70%, 10% to 20%, 5% to 15%, 6% to 12%, 0.1% to 0.15%, 1% to 2%, and 30% to 40% by mass of mixture a, quicklime, cement, gypsum, aluminum powder, JCA-2 water reducer, and water, respectively, mix them, adjust Ca / Si to 0.6 to 0.85, and then stir to obtain mixture b;

[0012] A2. Pour the mixture b, allow it to expand by foaming, cut it statically and autoclave it to obtain an aerated concrete block.

[0013] Preferably, the method for preparing the road red mud subgrade material in step S3 is specifically as follows:

[0014] B1. Take 85% to 95%, 5% to 15%, and 1% to 5% by mass of mixture a, quicklime, and cement, respectively, mix them, and stir them evenly to obtain red mud roadbed materials.

[0015] Preferably, the preparation method of ceramsite in step S3 is specifically as follows:

[0016] C1, drying the mixture a and grinding it into powder c;

[0017] C2, take 90% to 95% by mass of powder c, add 5% to 10% by mass of carbon powder or coal gangue powder, mix and stir evenly, and then make solid particles d;

[0018] C3. Calcine and swell the solid particles d, and obtain ceramsite after cooling.

[0019] Preferably, the particle size of the solid particles d is 5 mm to 20 mm.

[0020] Preferably, the calcination swelling is carried out at a temperature of 1000° C. to 1200° C. and for a time of 20 min to 60 min.

[0021] Preferably, the mixture a after adjusting the pH value in step S2 can also be directly used as improved soil.

[0022] After adopting the above technical solution, the present invention has the following advantages compared with the background technology:

[0023] The present invention provides a cascade utilization method for industrial waste residues based on red mud and nickel sulfate slag, which utilizes the nature of the nickel sulfate slag and its high Si and Ca content components to naturally neutralize the alkalinity of the red mud, increase the Si and Ca ratio of the red mud, enhance the activity of the red mud, and add other auxiliary materials to prepare aerated concrete blocks, lightweight ceramsite, road red mud base materials and improved soil, thereby converting industrial waste into a variety of building material resources, improving the utilization rate of red mud and nickel sulfate slag, and enhancing the industrialization level of comprehensive utilization of industrial waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure is a flow chart of the method of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] Example 1

[0027] like Figure 1 As shown, the present invention discloses a cascade utilization method of industrial waste residue based on red mud and nickel sulfate slag, comprising the following steps:

[0028] S1, respectively taking 450g of nickel sulfate slag and 500g of red mud mixture, stirring evenly to obtain a mixture a;

[0029] S2, adjusting the pH value of the mixture a to 7;

[0030] S3. Take 500g of mixture a, 120g of quicklime, 90g of cement, 10g of gypsum, 2g of aluminum powder, 10g of JCA-2 water reducer, and 390g of water, mix them, adjust Ca / Si to 0.73, and then stir evenly to obtain mixture b.

[0031] The mixture b is poured, foamed and expanded, statically cut and autoclaved to obtain aerated concrete blocks.

[0032] Example 2

[0033] like Figure 1 As shown, the present invention discloses a cascade utilization method of industrial waste residue based on red mud and nickel sulfate slag, comprising the following steps:

[0034] S1. Take 500 g of nickel sulfate slag and 600 g of red mud mixture respectively, stir evenly, and obtain mixture a;

[0035] S2, adjusting the pH value of the mixture a to 7.2;

[0036] S3. Take 450g of mixture a, 110g of quicklime, 85g of cement, 8g of gypsum, 1g of aluminum powder, 8g of JCA-2 water reducer, and 360g of water respectively, mix them, adjust Ca / Si to 0.78, and then stir evenly to obtain mixture b.

[0037] The mixture b is poured, foamed and expanded, statically cut and autoclaved to obtain aerated concrete blocks.

[0038] Example 3

[0039] like Figure 1 As shown, the present invention discloses a cascade utilization method of industrial waste residue based on red mud and nickel sulfate slag, comprising the following steps:

[0040] S1, take 450g of nickel sulfate slag and 550g of red mud mixture respectively, stir evenly, and obtain mixture a;

[0041] S2, adjusting the pH value of the mixture a to 7.1;

[0042] S3, respectively taking 450g of mixture a, 500g of quicklime, and 10g of cement, mixing them, stirring evenly, to obtain red mud roadbed material.

[0043] Example 4

[0044] like Figure 1 As shown, the present invention discloses a cascade utilization method of industrial waste residue based on red mud and nickel sulfate slag, comprising the following steps:

[0045] S1, respectively taking 550g of nickel sulfate slag and 700g of red mud mixture, stirring evenly to obtain a mixture a;

[0046] S2, adjusting the pH value of the mixture a to 7.3;

[0047] S3, respectively taking 500g of mixture a, 60g of quicklime, and 12g of cement, mixing them, stirring evenly, to obtain red mud roadbed material.

[0048] Example 5

[0049] like Figure 1 As shown, the present invention discloses a cascade utilization method of industrial waste residue based on red mud and nickel sulfate slag, comprising the following steps:

[0050] S1, take 450g of nickel sulfate slag and 550g of red mud mixture respectively, stir evenly, and obtain mixture a;

[0051] S2, adjusting the pH value of the mixture a to 7.1;

[0052] S3, drying the mixture a and grinding it into powder c;

[0053] Take 450g of powder c, add 50g of carbon powder, mix and stir evenly, and use a spheroidizer to form solid particles d. The particle size of the solid particles d is 5mm to 20mm.

[0054] The solid particles d were calcined and swelled at a temperature of 1150° C. for 25 min, and ceramsite was obtained after cooling.

[0055] Example 6

[0056] like Figure 1 As shown, the present invention discloses a cascade utilization method of industrial waste residue based on red mud and nickel sulfate slag, comprising the following steps:

[0057] S1. Take 600 g of nickel sulfate slag and 800 g of red mud mixture respectively, stir evenly, and obtain mixture a;

[0058] S2, adjusting the pH value of the mixture a to 7.4;

[0059] S3, drying the mixture a and grinding it into powder c;

[0060] Take 450g of powder c, add 50g of carbon powder, mix and stir evenly, and use a spheroidizer to form solid particles d. The particle size of the solid particles d is 5mm to 20mm.

[0061] The solid particles d were calcined and swelled at a temperature of 1200° C. for 40 min, and ceramsite was obtained after cooling.

[0062] Example 7

[0063] like Figure 1 As shown, the present invention discloses a cascade utilization method of industrial waste residue based on red mud and nickel sulfate slag, comprising the following steps:

[0064] S1. Take 600 g of nickel sulfate slag and 800 g of red mud mixture respectively, stir evenly, and obtain mixture a;

[0065] S2, adjusting the pH value of the mixture a to 7.4;

[0066] S3. The mixture a after adjusting the pH value in step S2 can also be directly used as improved soil.

[0067] Among them, nickel sulfate slag refers to the waste insoluble material after nickel sulfate is prepared by leaching laterite nickel ore with sulfuric acid during the hydrometallurgical nickel smelting process. Nickel sulfate slag and red mud are complementary and neutralizing. When red mud is mixed with nickel sulfate slag, the high content of Si and Ca in nickel sulfate slag can enhance the activity of red mud. The acidity of nickel sulfate slag can naturally neutralize the alkalinity of red mud to achieve acid-base balance.

[0068] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention 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 cascade utilization method of industrial waste residues based on red mud and nickel sulfate slag, characterized in that: The following steps are involved: S1. Take a mixture of nickel sulfate slag and red mud in a ratio of 1:1 to 2.5 parts by mass, stir evenly, and obtain a mixture a; S2, adjusting the pH value of the mixture a to 6.5-7.5; S3, taking several groups of mixtures a after adjusting the pH value, adding different auxiliary materials respectively, and preparing aerated concrete blocks, road red mud subgrade materials and building ceramsite.

2. The method for cascade utilization of industrial waste residues based on red mud and nickel sulfate slag according to claim 1, characterized in that: The method for preparing the aerated concrete block in step S3 is specifically as follows: A1. Take 30% to 70%, 10% to 20%, 5% to 15%, 6% to 12%, 0.1% to 0.15%, 1% to 2%, and 30% to 40% by mass of mixture a, quicklime, cement, gypsum, aluminum powder, JCA-2 water reducer, and water, respectively, mix them, adjust Ca / Si to 0.6 to 0.85, and then stir to obtain mixture b; A2. Pour the mixture b, allow it to expand by foaming, cut it statically and autoclave it to obtain an aerated concrete block.

3. The method for cascade utilization of industrial waste residues based on red mud and nickel sulfate slag according to claim 1, characterized in that: The method for preparing the red mud roadbed material in step S3 is specifically as follows: B1. Take 85% to 95%, 5% to 15%, and 1% to 5% by mass of mixture a, quicklime, and cement, respectively, mix them, and stir them evenly to obtain red mud roadbed materials.

4. The method for cascade utilization of industrial waste residues based on red mud and nickel sulfate slag according to claim 1, characterized in that: The preparation method of ceramsite described in step S3 is specifically as follows: C1, drying the mixture a and grinding it into powder c; C2, take 90% to 95% by mass of powder c, add 5% to 10% by mass of carbon powder or coal gangue powder, mix and stir evenly, and then make solid particles d; C3. Calcine and swell the solid particles d, and obtain ceramsite after cooling.

5. The method for cascade utilization of industrial waste residues based on red mud and nickel sulfate slag as claimed in claim 4, characterized in that: The particle size of the solid particles d is 5 mm to 20 mm.

6. The method for cascade utilization of industrial waste residues based on red mud and nickel sulfate slag as claimed in claim 4, characterized in that: The calcination and swelling process is carried out at a temperature of 1000° C. to 1200° C. and for a time of 20 min to 60 min.

7. The method for cascade utilization of industrial waste residues based on red mud and nickel sulfate slag according to claim 1, characterized in that: The mixture a after adjusting the pH value in step S2 can also be directly used as improved soil.

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