Heavy metal curing baking-free brick based on copper mine tailings and preparation method of heavy metal curing baking-free brick

Abstract

The invention discloses a heavy metal curing baking-free brick based on copper mine tailings and a preparation method thereof, and belongs to the technical field of solid waste resource utilization, the heavy metal curing baking-free brick comprises the following raw materials by weight: 2-3 parts of lime, 7-9 parts of slag, 6-11 parts of cement, 65-75 parts of copper mine tailings, 0.5-1.5 parts of nano silica, and 3-5 parts of modified metakaolin. According to the method, the copper mine tailings can be effectively treated, heavy metal elements in the tailings can be solidified, environmental pollution and resource waste can be reduced, the baking-free bricks with good performance can be prepared, the using requirements of the fields such as buildings are met, remarkable economic and environmental benefits are achieved, and a feasible and effective way is provided for comprehensive utilization of the copper mine tailings. In addition, the preparation method provided by the invention is simple and convenient to popularize and apply.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solid waste resource utilization, and particularly relates to a heavy metal solidified non-burned brick based on copper mine tailings and a preparation method thereof. BACKGROUND

[0002] Long-term mining and smelting production activities have caused prominent accumulation of mineral solid waste, and the tailings stockpile has a huge stock of tailings, which has caused increasingly prominent environmental and safety problems. The tailings stockpile not only occupies land resources, but also causes heavy metal pollution of soil and water bodies. Research data show that the copper mine tailings contain harmful trace elements such as Pb, Cr, Ni, Cu, Cd, As and Zn. Compared with the Chongqing soil background value, the contents of Cd, Cu, Pb and Zn are higher than the background value. Therefore, long-term stockpiling of tailings in the tailings stockpile is easy to cause heavy metal pollution of the surrounding soil environment and even groundwater.

[0003] The copper mine tailings (WS) can be used as a mineral admixture to prepare a non-burned brick. The components are mixed according to an optimal ratio, and then pressed into shape after being mixed with cement. This not only solves the problem of environmental pollution caused by a large amount of solid waste accumulation and saves land resources, but also realizes the resource utilization of solid waste and creates economic benefits, which has important significance for environmental protection.

[0004] Therefore, how to provide a method for resource utilization of copper mine tailings is a technical problem that those skilled in the art urgently need to solve. SUMMARY

[0005] To solve the above technical problems, the application provides a heavy metal solidified non-burned brick based on copper mine tailings and a preparation method thereof.

[0006] To achieve the above purpose, the application provides the following technical solutions.

[0007] A heavy metal solidified non-burned brick based on copper mine tailings comprises the following raw materials in parts by weight:

[0008] lime 2-3 parts, slag 7-9 parts, cement 6-11 parts, copper mine tailings 65-75 parts, nano silicon dioxide 0.5-1.5 parts, and modified metakaolin 3-5 parts.

[0009] Beneficial effects: the application takes copper mine tailings as main materials, realizes the resource utilization of waste, reduces cost and is environment-friendly; M42.5 and M32.5 cement are mixed in a specific ratio to optimize performance; the addition of lime can improve the reaction activity, and the application also adds nano-silicon dioxide and modified metakaolin to enhance the strength and other performances of the brick, nano-silicon dioxide can be filled in the pores of cement stone and modified metakaolin hydration products, further refining the pore structure, improving the density and impermeability of the brick, and reducing the migration channel of heavy metal ions. At the same time, the crystal nucleus effect and chemical reaction activity of nano-silicon dioxide can enhance the solidification capacity of cement and modified metakaolin to heavy metals, and the three work together to effectively improve the solidification efficiency of heavy metals in copper mine tailings.

[0010] Preferably, the cement is M42.5 cement and M32.5 cement in a mass ratio of (3.5-6.6):(2.5-4.4).

[0011] Beneficial effects: the application selects M42.5 and M32.5 cement mixed in a specific mass ratio, which can optimize the performance of cement and make the strength and other indicators of the prepared heavy metal solidification non-fired brick better, meeting the use requirements.

[0012] Preferably, the lime is slaked lime.

[0013] Beneficial effects: slaked lime is alkaline, has high chemical activity, can fully react with other components in the system, promote the generation of cementitious materials, enhance the internal structure bonding force of the brick, effectively improve the strength and stability of the heavy metal solidification non-fired brick, and ensure the quality performance of the non-fired brick.

[0014] Preferably, the preparation method of the modified metakaolin comprises the following steps:

[0015] The kaolin is ball milled and calcined to obtain metakaolin, and the metakaolin is mixed with an organic modifier and ball milled to obtain the modified metakaolin.

[0016] Beneficial effects: the above modification method can improve the surface performance of metakaolin, enhance its compatibility with other raw materials, improve the reaction activity in the brick, and thus improve the strength and durability of the non-fired brick.

[0017] Preferably, the organic modifier comprises one of gamma-aminopropyl triethoxysilane, gamma-methacryloyloxypropyl trimethoxysilane, sodium polyacrylate and polymethylacrylic acid.

[0018] Beneficial effects: the above modifier can be effectively combined with metakaolin to improve its dispersibility and interfacial properties, enhance the adhesion with other components in the brick body, improve the compactness of the brick body structure, and further improve the strength and durability of the heavy metal solidified non-fired brick. In addition, the active groups generated on the surface of the modified metakaolin can be combined with heavy metal ions through chemical bonding, and the heavy metal ions can be fixed in the brick body structure. Moreover, the secondary hydration reaction of the modified metakaolin consumes calcium hydroxide generated by cement hydration, promotes further hydration of the cement, and generates more hydration products that are beneficial to solidification of heavy metals. In addition, the high specific surface area and active groups of the modified metakaolin increase the adsorption and fixation capacity of heavy metal ions, and the solidification effect of cement is complementary, thereby improving the overall solidification effect of heavy metals in copper mine tailings.

[0019] Preferably, the calcination temperature is 500-900℃, and the time is 1-4h.

[0020] Preferably, the mass ratio of metakaolin to organic modifier is (200-400):1.

[0021] Beneficial effects: the above specific calcination temperature and time can fully convert kaolin into metakaolin to ensure its activity; and the suitable mass ratio allows the organic modifier to better play a role in improving the performance of metakaolin, thereby synergistically improving the strength of non-fired brick, optimizing the internal structure of the brick body, and enhancing the stability and durability.

[0022] Preferably, the particle size distribution of the copper mine tailings is as follows: the mass fraction of particles with a particle size of 0.5-2mm is 36-42%, the mass fraction of particles with a particle size of 0.1-0.5mm is 29-38%, and the mass fraction of particles with a particle size of <0.1mm is 22-28%.

[0023] Beneficial effects: the present application utilizes copper mine tailings with different particle sizes to fill each other, which can effectively improve the compactness of the brick body, reduce internal pores, enhance the stability of the brick body structure, and further improve the strength, impermeability and other properties of the non-fired brick, so that the quality is better and more durable.

[0024] A preparation method of a heavy metal solidification non-fired brick based on copper mine tailings, comprising the following steps:

[0025] (1) drying, grinding and vibrating screening of the copper mine tailings to obtain copper mine tailings with different particle gradings;

[0026] (2) dry mixing of the copper mine tailings with different particle gradings, modified metakaolin, slag, cement, nano silicon dioxide and lime, then adding water and mixing uniformly to obtain a mixed slurry, and then performing hydraulic forming, demolding and curing on the mixed slurry to obtain the heavy metal solidification non-fired brick based on copper mine tailings.

[0027] Preferably, the water is added in a water-cement ratio of 0.5-0.9.

[0028] Compared with the prior art, the present application has the following advantages and technical effects:

[0029] The present application mainly uses a large amount of copper mine tailings as a main material, realizes the resource utilization of waste, reduces the cost and is environmentally friendly; the performance is optimized by mixing M42.5 and M32.5 cement in a specific ratio; nano-silicon dioxide and modified metakaolin are added to enhance the strength and other properties of the bricks. In addition, the particle size distribution of the copper mine tailings is optimized, which is beneficial to improve the compactness of the bricks. The present application not only effectively treats copper mine tailings, reduces environmental pollution and resource waste, but also prepares well-performing baking-free bricks to meet the use requirements in the field of building, has significant economic and environmental benefits, and provides a feasible and effective way for the comprehensive utilization of copper mine tailings. In addition, the preparation method is simple and convenient for popularization and application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with specific embodiments.

[0032] Unless otherwise specified, the raw materials in the embodiments of the present application are purchased through market channels;

[0033] The copper mine tailings are from Tongling Shumuchong tailings reservoir, and the main chemical components of the copper mine tailings are Cu, Tfe, S, Au and Ag, wherein the Cu grade is concentratedly distributed between 0.04-0.16%, the Tfe grade is concentratedly distributed between 6.55-12.85%, the S grade is concentratedly distributed between 0.74-2.99%, the Au grade is concentratedly distributed between 0.1-0.25g / t, and the Ag is concentratedly distributed between 1.81-11.59g / t; the SiO2 content in the tailings is generally 35-45%, which is lower than that of high-silica quartz sandstone, the CaO content is generally 18-20%, the MgO content is generally about 2%, the TFe2O3+Al2O3 content is generally 20-25%, and the alkali oxide K2O+Na2O content is generally 1.5-2%;

[0034] The slag is S105 grade blast furnace slag, a by-product of ironmaking, which is purchased from China Fuyang Xinyuan Building Material Co., Ltd.

[0035] Unless otherwise specified, room temperature or normal temperature in the embodiments of the present application refers to 25±3℃.

[0036] Embodiment 1

[0037] A heavy metal solidified non-fired brick based on copper mine tailings, comprising the following raw materials in parts by weight:

[0038] Quicklime 2.24 parts, slag 7.36 parts, cement (the mass ratio of M42.5 cement to M32.5 cement is 3.84:2.56) 6.4 parts, copper mine tailings (the mass fraction of particle size 0.5-2mm is 40%, the mass fraction of particle size 0.1-0.5mm is 35%, and the mass fraction of particle size <0.1mm is 25%). 71 parts, nano-silicon dioxide 0.53 parts, modified metakaolin 4.87 parts.

[0039] The preparation method of the modified metakaolin comprises the following steps:

[0040] The kaolin is ball milled and calcined at 700℃ for 3h to obtain metakaolin. The metakaolin is mixed with an organic modifier (γ-aminopropyl triethoxysilane) at a mass ratio of 300:1 and ball milled for 15min to obtain the modified metakaolin.

[0041] A preparation method of a heavy metal solidified non-fired brick based on copper mine tailings, comprising the following steps:

[0042] (1) The copper mine tailings are dried, ground and sieved by vibration to obtain copper mine tailings with different particle gradations;

[0043] (2) The copper mine tailings with different particle gradations, modified metakaolin, slag, cement, nano-silicon dioxide and quicklime are stirred and dry mixed, water is added at a water-cement ratio of 0.81, and the mixture is uniformly mixed. The obtained mixed slurry is formed by a hydraulic brick press at a hydraulic pressure of 10MPa for 45s, and after demolding, it is left to stand at room temperature for 12h and then naturally cured for 28d to obtain the heavy metal solidified non-fired brick based on copper mine tailings.

[0044] Embodiment 2

[0045] A heavy metal solidified non-fired brick based on copper mine tailings, comprising the following raw materials in parts by weight:

[0046] Quicklime 2.52 parts, slag 8.28 parts, cement (the mass ratio of M42.5 cement to M32.5 cement is 4.32:2.88) 7.2 parts, copper mine tailings (the mass fraction of particle size 0.5-2mm is 36%, the mass fraction of particle size 0.1-0.5mm is 38%, and the mass fraction of particle size <0.1mm is 26%). 69 parts, nano-silicon dioxide 1.12 parts, modified metakaolin 3.08 parts.

[0047] The preparation method of the modified metakaolin comprises the following steps:

[0048] The kaolin is ball milled and calcined at 500 DEG C for 4h to obtain metakaolin, and the metakaolin is mixed with an organic modifier (sodium polyacrylate) at a mass ratio of 200:1 and ball milled for 10 min to obtain the modified metakaolin.

[0049] A preparation method of a heavy metal solidified non-fired brick based on copper mine tailings, comprising the following steps:

[0050] (1) The copper mine tailings are dried, ground and sieved by vibration to obtain copper mine tailings with different particle gradations;

[0051] (2) The copper mine tailings with different particle gradations, modified metakaolin, slag, cement, nano silicon dioxide and hydrated lime are stirred and dry-mixed, water is added at a water-cement ratio of 0.73, and the mixture is uniformly mixed to obtain a mixed slurry, the obtained mixed slurry is formed by a hydraulic brick press at a hydraulic pressure of 20 MPa for 60 s, and after demolding, the mixture is left to stand and cure at room temperature for 6 h, and then naturally cured for 28 d to obtain the heavy metal solidified non-fired brick based on copper mine tailings.

[0052] Example 3

[0053] A heavy metal solidified non-fired brick based on copper mine tailings, comprising the following raw materials in parts by weight:

[0054] Hydrated lime 2.64 parts, slag 8.36 parts, cement (M42.5 cement and M32.5 cement at a mass ratio of 6.6:4.4) 11 parts, copper mine tailings (mass fraction of particle size 0.5-2 mm is 42%, mass fraction of particle size 0.1-0.5 mm is 30%, mass fraction of particle size <0.1 mm is 28%) 67 parts, nano silicon dioxide 1.37 parts, and modified metakaolin 4.68 parts.

[0055] The preparation method of the modified metakaolin comprises the following steps:

[0056] The kaolin is ball milled and calcined at 900 DEG C for 1h to obtain metakaolin, and the metakaolin is mixed with an organic modifier (polymethylacrylic acid) at a mass ratio of 400:1 and ball milled for 20 min to obtain the modified metakaolin.

[0057] A preparation method of a heavy metal solidified non-fired brick based on copper mine tailings, comprising the following steps:

[0058] (1) The copper mine tailings are dried, ground and sieved by vibration to obtain copper mine tailings with different particle gradations;

[0059] (2) Copper mine tailings with different particle size distribution, modified metakaolin, slag, cement, nano-silica, and hydrated lime were dry mixed, and then water was added with a water-cement ratio of 0.59 to obtain a mixed slurry. The mixed slurry was formed into a brick by a hydraulic press at 30 MPa for 30 s, and then demolded and cured at room temperature for 12 h, and then cured naturally for 28 d to obtain a heavy metal solidified unfired brick based on copper mine tailings.

[0060] Comparative Example 1

[0061] The difference from Example 1 is that the copper mine tailings are composed of particles with a particle size of 0.5-2 mm. The remaining process steps and parameters are the same as those of Example 1.

[0062] Comparative Example 2

[0063] The difference from Example 1 is that only M42.5 cement is used, i.e., the M32.5 cement is replaced with an equal amount of M42.5 cement. The remaining process steps and parameters are the same as those of Example 1.

[0064] Comparative Example 3

[0065] The difference from Example 1 is that only M32.5 cement is used, i.e., the M42.5 cement is replaced with an equal amount of M32.5 cement. The remaining process steps and parameters are the same as those of Example 1.

[0066] Comparative Example 4

[0067] The difference from Example 1 is that the cement is replaced with an equal amount of copper mine tailings. The remaining process steps and parameters are the same as those of Example 1.

[0068] Comparative Example 5

[0069] The difference from Example 1 is that the modified metakaolin is replaced with an equal amount of metakaolin. The remaining process steps and parameters are the same as those of Example 1.

[0070] Comparative Example 6

[0071] The difference from Example 1 is that no nano-silica is added. The remaining process steps and parameters are the same as those of Example 1.

[0072] Technical effects:

[0073] 1. Mechanical properties

[0074] The flexural strength and compressive strength of the cement mortar materials obtained in Examples 1-3 and Comparative Examples 1-6 were tested according to the test methods of GB / T4741-1999 Ceramic Materials Flexural Strength Test Method and GB / T21144-2007 Compressive Strength Test Method, and the results are shown in Table 1:

[0075] Table 1

[0076]

[0077]

[0078] As can be seen from Table 1, the compressive and flexural strengths of the copper mine tailings-based heavy metal solidified unburned bricks prepared in Examples 1-3 are both high, indicating that the unburned bricks prepared according to the given raw material ratio and process have good mechanical properties. In Comparative Example 1, only the particle size composition of the copper mine tailings is changed, and the strength is greatly reduced, indicating that a reasonable particle size distribution plays a key role in the strength; in Comparative Examples 2-3, the type of cement is changed, and the strength is reduced, reflecting the advantages of mixing the two types of cement in a certain proportion; in Comparative Example 4, the cement is removed, and the strength is greatly reduced, highlighting the important role of cement; in Comparative Example 5, kaolin is used to replace modified metakaolin, and in Comparative Example 6, no nano-silicon dioxide is added, and the strength is reduced, which shows that the two have a certain synergistic effect to some extent, and together improve the mechanical properties of the bricks.

[0079] 2. Heavy metal content test of unburned brick

[0080] 2.1 From Table 2, the occurrence of heavy metals in copper mine tailings and unburned bricks of Examples 1-3 and Comparative Examples 1-6 can be known.

[0081] Table 2 Average value of total heavy metal elements mg / kg

[0082]

[0083]

[0084] In the unburned bricks of Examples 1-3, the total amount of the four heavy metal elements exceeds the soil environmental background value of Tongling City, the Cd element exceeds the standard by 1.45-2.33 times, the Cu element exceeds the standard by 7.35-10.30 times, the As element exceeds the standard by 1.69-2.09 times, the Pb element exceeds the standard by 0.98-1.37 times, and the Zn element exceeds the standard by 1.92-2.44 times. The total amount of the four heavy metal elements in the unburned bricks of Comparative Examples 1-6 also greatly exceeds the soil environmental background value of Tongling City.

[0085] 2.2 Heavy metal solidification effect of copper mine tailings-based heavy metal solidified unburned brick

[0086] Based on the copper mine tailings of heavy metal solidification of leaching toxicity of brick, the use of three kinds of solid waste leaching toxicity of the People's Republic of China environmental protection industry standard leaching method, strictly in accordance with the standard method of leaching procedure, copper mine tailings of heavy metal toxicity of leaching were determined, the leaching solution of heavy metal elements using the recommended method - inductively coupled plasma atomic emission spectrometry for determination. The concentration of harmful ingredients in the three methods of toxicity leaching solution value see table 3.

[0087] Sulfuric acid nitric acid method with nitric acid / sulfuric acid mixed solution as leaching agent, simulation of waste in not standard landfill disposal, storage, or after the waste of land use, the harmful components in the acid rain under the influence of, from the waste into the environment and the process of leaching. According to the "hazardous waste identification standard leaching toxicity identification" (GB 5085.3-2007), based on the copper mine tailings of heavy metal solidification of brick according to the sulfuric acid nitric acid method (HJ / T 299-2007) preparation of solid waste leaching solution, Cd, Cu, Pb and Zn four kinds of heavy metal element concentration value did not exceed the concentration limit value listed in the "hazardous waste identification standard leaching toxicity identification", so as to determine the copper mine tailings of heavy metal solidification of brick does not have the characteristics of leaching toxicity.

[0088] Horizontal oscillation method (HJ 557-2010) with pure water as leaching agent, simulation of solid waste in the specific occasion by surface water or groundwater leaching, the harmful components in the process of leaching into the environment. Based on the copper mine tailings of heavy metal solidification of brick horizontal oscillation method leaching solution of Cd, Cu, Pb and Zn four kinds of heavy metal element concentration value did not exceed the concentration limit value listed in the "hazardous waste identification standard leaching toxicity identification".

[0089] Acetic acid buffer solution method (HJ / T300-2007) with acetic acid buffer solution as leaching agent, simulation of industrial waste into sanitary landfill, the harmful components in the landfill leachate under the influence of leaching from the waste. Based on the copper mine tailings of heavy metal solidification of brick acetic acid buffer solution method leaching solution of Cd, Cu, Pb and Zn four kinds of heavy metal element concentration value did not exceed the concentration limit value listed in the "hazardous waste identification standard leaching toxicity identification".

[0090] In addition, according to the "surface water environmental water environmental quality standard" (GB3838-2002), based on the copper mine tailings of heavy metal solidification of brick three kinds of toxicity leaching method, the concentration of Cd in the leaching solution reached the I class water quality standard, Cu and Pb concentration value reached the II class water quality standard, the concentration of Zn reached the I-II class water quality standard.

[0091] According to the Groundwater Quality Standard (GB / T 14848-2017), the concentration of Cd in the leaching solution of the copper mine tailings-based heavy metal solidified unfired brick reaches the Class I water quality standard, the concentration of Cu reaches the Class II water quality standard, the concentration of Pb reaches the Class IV water quality standard, and the concentration of Zn reaches the Class I-II water quality standard.

[0092] Table 3: Concentration of hazardous components in the leaching solution / mg / L

[0093]

[0094]

[0095] Note: ND represents not detected.

[0096] The acidity of the leaching agent in the sulfuric acid-nitric acid method is pH 3.20±0.05, and the acidity of the leaching agent in the acetic acid buffer solution method is 4.93±0.05, which is relatively extreme compared with the pure water (pH=7.0±0.05) of the horizontal oscillation method, simulating the heavy metal leaching under the influence of acid rain and landfill leachate. Therefore, the copper mine tailings-based heavy metal solidified unfired brick has good solidification effect on Cd, Cu, Pb and Zn under extreme acid conditions or neutral conditions, and the solidification effect of the copper mine tailings-based heavy metal solidified unfired brick of Example 3 is better than that of Example 2 and Example 1. In addition, it can be seen from the experimental data of the comparative example that the nano-silicon dioxide, the particle size distribution of the copper mine tailings and the modification of the kaolin in the present application can effectively inhibit the precipitation of heavy metals, and have good effect of solidifying heavy metals.

[0097] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A heavy metal stabilized non-fired brick based on copper mine tailings, characterized in that, The raw materials include the following components in parts by weight: lime 2-3 parts, slag 7-9 parts, cement 6-11 parts, copper mine tailings 65-75 parts, nano-silica 0.5-1.5 parts, and modified metakaolin 3-5 parts.

2. A heavy metal stabilized fired brick based on copper mine tailings according to claim 1, characterized in that, The cement is M42.5 cement and M32.5 cement in a mass ratio of (3.5-6.6):(2.5-4.4).

3. A heavy metal stabilized fired brick based on copper mine tailings according to claim 1, characterized in that, The lime is slaked lime.

4. A heavy metal stabilized fired brick based on copper mine tailings according to claim 1, characterized in that, The preparation method of the modified metakaolin includes the following steps: ball-milling and calcining kaolin to obtain metakaolin, and ball-milling the metakaolin and an organic modifier to obtain the modified metakaolin.

5. A heavy metal stabilized fired brick based on copper mine tailings according to claim 4, characterized in that, The organic modifier includes one of γ-aminopropyl triethoxysilane, γ-methacryloyloxypropyl trimethoxysilane, sodium polyacrylate, and polymethylacrylic acid.

6. A heavy metal stabilized fired brick based on copper mine tailings according to claim 4, characterized in that, The calcining temperature is 500-900 DEG C, and the time is 1-4 h.

7. A heavy metal stabilized fired brick based on copper mine tailings according to claim 4, characterized in that, The mass ratio of the metakaolin to the organic modifier is (200-400):

1.

8. A heavy metal stabilized fired brick based on copper mine tailings according to claim 1, characterized in that, The particle size distribution of the copper mine tailings is as follows: the mass fraction of particles with a particle size of 0.5-2 mm is 36-42%, the mass fraction of particles with a particle size of 0.1-0.5 mm is 29-38%, and the mass fraction of particles with a particle size of <0.1 mm is 22-28%.

9. A process for the production of a heavy metal stabilized unburnt brick based on copper mine tailings according to any one of claims 1 to 8, characterized in that, The method includes the following steps: (1) drying and grinding the copper mine tailings and sieving by vibration to obtain copper mine tailings with different particle gradations; (2) stirring and dry mixing the copper mine tailings with different particle gradations, modified metakaolin, slag, cement, nano-silica, and lime, adding water in a water-cement ratio of 0.5-0.9, and uniformly mixing to obtain a mixed slurry, and then performing hydraulic forming, demolding, and curing to obtain the heavy metal solidification baking-free brick based on copper mine tailings.

10. A process for the production of a heavy metal stabilized sintered brick based on copper mine tailings according to claim 9, characterized in that, The water is added in a water-cement ratio of 0.5-0.9.

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