Tailing mud aggregate inorganic stone paint and preparation method thereof

Abstract

This invention discloses an inorganic stone-like paint using tailings sludge aggregate and its preparation method. The inorganic stone-like paint consists of five parts: an inorganic cementitious main component, a setting regulator component, a pigment component, an anti-efflorescence component, and a viscosity-adjusting and thickening component. This invention uses tailings sludge instead of traditional construction sand as aggregate, and inorganic cementitious materials instead of polymer emulsions as the matrix. It also utilizes the ion exchange properties of calcium-based bentonite to solve the problem of efflorescence in cement-based mortar when exposed to water. The paint features good adhesion to building substrates, high hardness, environmental friendliness, water resistance, durability, no efflorescence, low cost, fast curing speed, and a simple preparation process.

Description

Technical Field

[0001] This invention relates to a novel building material, specifically to an inorganic stone-like paint made from tailings mud aggregate and its preparation method, belonging to the field of civil engineering materials technology. Background Technology

[0002] Tailings are industrial waste generated during mining and mineral processing. In recent years, due to the limited mining and shortage of natural building sand and gravel aggregates, coarse particles in tailings have been screened out and used as manufactured sand. However, the fine tailings mud remaining after screening is too fine, has a large specific surface area, and a high water absorption rate, making it unsuitable for use as construction sand. Currently, it has no suitable use and is piled up in tailings ponds. The accumulation of these tailings mud not only occupies land and pollutes the environment but also easily leads to safety hazards such as dam failures and debris flows, becoming a public nuisance. Therefore, the development and utilization of tailings mud can not only turn waste into treasure but also reduce environmental pollution and eliminate safety hazards.

[0003] Stone-like paint, also known as sand-textured coating, is a commonly used exterior wall decoration material. As one of the alternatives to dry-hanging stone cladding on building exteriors, stone-like paint is mainly formulated with natural stone powder of various colors and polymer film-forming substances, giving the building exterior a stone-like effect. The film-forming substances in traditional stone-like paint are mainly polymer emulsions and their additives. After coating, they form a continuous network, which not only binds various inorganic particles together but also provides waterproofing for the coating. Therefore, they are indispensable substances in traditional stone-like paint. However, the use of these polymer emulsions and their additives not only increases the cost of stone-like paint but may also lead to VOC pollution or aging problems.

[0004] Cement finishing mortar is also a commonly used building exterior wall decoration material. Also known as cement-based multi-colored decorative powder (or simply colored mortar), it features natural color and texture, soft visual appeal, low cost, and ease of application. However, traditional cement finishing mortar is prone to efflorescence when exposed to water, affecting the decorative effect. Furthermore, like stone paint, traditional cement finishing mortar uses high-quality colored sand or quartz sand, at least meeting construction standards, resulting in a higher cost.

[0005] Therefore, if an inorganic stone-like paint product can be prepared using tailings mud as aggregate without the need for polymer film-forming substances, and the problem of "efflorescence" in cement-coated mortar can be solved, the cost of stone-like paint can be reduced and its durability improved. This is of great significance for the resource utilization of tailings mud and the development of building exterior wall decoration materials. Summary of the Invention

[0006] This invention addresses the resource utilization of tailings mud, the cost and environmental issues of real stone paint, and the "efflorescence" problem of decorative mortar. The purpose is to provide an inorganic real stone paint material using tailings mud as aggregate and its preparation method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An inorganic stone-like paint based on tailings sludge aggregate is disclosed. This inorganic stone-like paint comprises five parts: an inorganic cementitious main component, a setting regulator component, a pigment component, an anti-efflorescence component, and a viscosity-adjusting and thickening component. The inorganic cementitious main component consists of white silicate cement, tailings sludge, silica fume, a water-reducing agent, and water. The setting regulator component consists of calcium formate, aluminum sulfate, and triethanolamine. The pigment component consists of titanium dioxide and inorganic colored pigments. The anti-efflorescence component is calcium-based bentonite. The viscosity-adjusting and thickening component consists of hydroxypropyl methylcellulose and sodium dodecyl sulfate.

[0009] The aforementioned inorganic stone-like paint using tailings sludge aggregate comprises: cement of strength grade 42.5 white silicate cement in the inorganic cementitious main component; tailings sludge with a particle size smaller than the requirements of national standard GB / T 14684-2011 and industry standard JGJ 52-2006, an apparent relative density >2.5, a methylene blue MB value <1.4, and whose harmful substance content, soundness, and alkali-aggregate reaction index all meet the requirements of GB / T 14684-2011; and a polycarboxylate-based high-efficiency water-reducing agent. The weight ratio of each raw material is: cement : tailings sludge : silica fume : water-reducing agent : water = (13-21) : (79-87) : 1.5 : (0.2-0.4) : (13.5-16.5).

[0010] The aforementioned inorganic stone-like paint made from tailings mud aggregate has a setting-regulating component that mainly plays the role of regulating the curing and setting speed of the stone-like paint. Calcium formate, aluminum sulfate, and triethanolamine are composed in a ratio of (0.2-0.5):(0.5-0.8):0.03.

[0011] The aforementioned inorganic stone-like paint for tailings sludge aggregate uses one or more of the following inorganic color pigments: iron oxide red, chrome green, ochre yellow, and cadmium orange. The weight ratio of the inorganic color pigment to titanium dioxide is 3.0:6.0.

[0012] The aforementioned inorganic stone-like paint using tailings sludge aggregate comprises 2.0 parts by weight of calcium-based bentonite as its anti-efflorescence component. The purpose is to utilize the ion exchange function of calcium-based bentonite, allowing alkali metal ions such as sodium and potassium in the inorganic stone-like paint system to exchange with calcium ions between the aluminosilicate layers of bentonite, thus enabling these ions to enter the aluminosilicate layers. This ion exchange not only prevents the efflorescence of alkali metal ions from the coating upon contact with water, thus avoiding its impact on appearance, but also improves the plasticity and adhesion of the bentonite by transforming it into artificial sodium-based or potassium-based clay, thereby enhancing the suspension stability, viscosity, and workability of the coating. The calcium ions exchanged from the bentonite can then participate in the cement hydration process, generating hydraulic hydration products.

[0013] The aforementioned inorganic stone-like paint for tailings mud aggregate comprises a viscosity-adjusting and thickening component consisting of 0.001 parts by weight of sodium dodecyl sulfate and 0.002 parts by weight of hydroxypropyl methylcellulose with a viscosity of 5-100,000 mPa·s.

[0014] This invention also provides a method for preparing inorganic stone-like paint from tailings mud aggregate, comprising the following steps:

[0015] Step 1: Weigh the titanium dioxide, silica fume, colored pigments and calcium-based bentonite separately and put them into a ball mill. Mix and grind for 0.5 hours to obtain dry material A;

[0016] Step 2: Mix and stir the water-reducing agent, cellulose, sodium dodecyl sulfate and 80% water until they are evenly dissolved to obtain liquid A;

[0017] Step 3: Mix calcium formate, aluminum sulfate, and triethanolamine with the remaining 20% ​​water and stir until dissolved to obtain liquid B;

[0018] Step 4: Add white cement and tailings mud to a mixer and mix for 2 minutes to obtain dry material B;

[0019] Step 5: Mix dry material B and dry material A in a mixer for 2 minutes; then add liquid A and mix for another 2 minutes; finally add liquid B and mix thoroughly to obtain inorganic stone paint. The obtained stone paint should be sprayed and used immediately, and should be used within 1.0-2.0 hours.

[0020] The advantages of this invention are:

[0021] 1. This invention uses white silicate cement combined with setting regulator as a cementing material, and generates an inorganic composite cement as a matrix through rapid reaction, which replaces the traditional polymer emulsion film-forming material. This not only reduces costs, but also avoids the VOC pollution and aging problems of polymer film-forming materials.

[0022] 2. This invention utilizes the ion exchange properties of calcium-based bentonite to solve the problems of efflorescence and whitening that easily occur when cement-based decorative mortar materials come into contact with water;

[0023] 3. The inorganic hydration products generated by the reaction in this invention have good adhesion to the building substrate, and the products themselves have high hardness, good water resistance, and strong durability.

[0024] 4. The addition of the setting-regulating component in this invention can adjust the setting time of the coating after spraying. Compared with ordinary cement-based mortar, it shortens the curing time and construction cycle, and improves the construction efficiency of the coating.

[0025] 5. This invention uses industrial waste tailings mud as aggregate and combines it with inorganic colored pigments to replace traditional colored sand, construction sand or quartz sand. The raw materials are inexpensive, the production process is simple, and the construction is convenient. Example

[0026] The present invention will be further described below with reference to specific embodiments.

[0027] I. Raw Materials

[0028] (1) Building materials raw materials

[0029] It uses 42.5# white silicate cement, polycarboxylate superplasticizer, triethanolamine, tap water and silica fume, which comply with current national and industry standards.

[0030] (2) Tailings slime

[0031] Iron ore tailings mud or gold ore tailings mud is used, with a fineness modulus of 0.6, apparent relative density of 2.6, methylene blue test MB value <1.4, and the content of harmful substances, soundness, and alkali-aggregate reaction index all meet the requirements of GB / T 14684-2011 standard.

[0032] (3) Chemical raw materials

[0033] The products used are industrial-grade calcium formate, aluminum sulfate, hydroxypropyl methylcellulose, sodium dodecyl sulfate, calcium bentonite, titanium dioxide, and colored pigments such as iron oxide red, chrome green, ochre yellow, and cadmium orange, all of which conform to national or industry standards.

[0034] II. Formulation and Preparation Process

[0035] (1) Preparation of powder A

[0036] The ingredients were prepared according to the mass ratio of titanium dioxide: silica fume: colored pigment: calcium bentonite = 6.0: 1.5: 3.0: 2.0, and then put into a ball mill for mixing and grinding for 0.5 hours to obtain powder A.

[0037] (2) Preparation of liquid A

[0038] The ingredients are prepared according to the mass ratio of polycarboxylate superplasticizer: hydroxypropyl methylcellulose: sodium dodecyl sulfate: water = (0.2-0.4): 0.002: 0.001: (10.8-13.2), and stirred to dissolve and mix evenly to obtain liquid A;

[0039] (3) Preparation of liquid B

[0040] Prepare the mixture according to the mass ratio of calcium formate: aluminum sulfate: triethanolamine: water: (0.2-0.5): (0.5-0.8): 0.03: (2.7-3.3), and stir to dissolve and mix evenly to obtain liquid B;

[0041] (4) Preparation of dry material B

[0042] The materials are mixed in a mass ratio of cement to tailings mud of (13-21): (79-87), and then mixed in a mixer for 2 minutes to obtain dry material B.

[0043] (5) Preparation of Inorganic Stone Paint

[0044] Mix the prepared dry materials B and A in a mixer for 2 minutes; then add liquid A and mix for another 2 minutes; finally add liquid B and stir immediately until homogeneous to obtain inorganic stone paint. Apply immediately and use within 1.0-2.0 hours.

[0045] III. Performance Test Results

[0046] The table below shows the formulation ratios of the inorganic stone paint in each embodiment and the performance of the inorganic stone paint tested according to the methods of JC / T 1024-2019 and GB / T50081-2019.

[0047]

[0048]

[0049] The table above shows that the performance of the inorganic stone paint in each embodiment meets the performance requirements of current standards.

[0050] The inorganic stone paint of this invention uses industrial waste tailings mud as aggregate, inorganic cementitious materials to replace polymer emulsion as matrix, and utilizes the ion exchange characteristics of calcium-based bentonite to solve the problem of efflorescence in cement-based mortar when exposed to water. It has the characteristics of good adhesion to building substrate, high strength, environmental protection, water resistance, durability, no efflorescence, low cost, fast curing speed, and simple preparation process.

[0051] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An inorganic stone-like paint for tailings mud aggregate, characterized in that, This inorganic stone-like paint consists of five parts: an inorganic cementitious main component, a setting modifier, a pigment component, an anti-efflorescence component, and a viscosity modifier and thickener. The inorganic cementitious main component is composed of white silicate cement, tailings sludge, silica fume, water-reducing agent, and water. The setting modifier is composed of calcium formate, aluminum sulfate, and triethanolamine. The pigment component is composed of titanium dioxide and inorganic colored pigments. The anti-efflorescence component is calcium-based bentonite. The viscosity modifier and thickener is composed of hydroxypropyl methylcellulose and sodium dodecyl sulfate.

2. The inorganic stone-like paint made from tailings mud aggregate according to claim 1, wherein the weight ratio of each raw material in the inorganic cementitious main component is: white silicate cement: tailings mud: silica fume: water-reducing agent: water = (13-21): (79-87): 1.5: (0.2-0.4): (13.5-16.5); The weight ratio of each raw material in its coagulation regulating component is: calcium formate: aluminum sulfate: triethanolamine = (0.2-0.5): (0.5-0.8): 0.03; the weight ratio of inorganic color pigment to titanium dioxide in its pigment component is 3.0:6.0; the anti-efflorescence component uses 2.0 parts by weight of calcium-based bentonite; Its viscosity-adjusting and thickening components consist of 0.001 parts by weight of sodium dodecyl sulfate and 0.002 parts by weight of hydroxypropyl methylcellulose with a viscosity of 50,000-100,000 mPa·s.

3. The inorganic stone-like paint for tailings mud aggregate according to claim 1, its preparation method includes the following steps: Step 1: Weigh the titanium dioxide, silica fume, inorganic color pigments and calcium-based bentonite separately and put them into a ball mill. Mix and grind for 0.5 hours to obtain dry material A; Step 2: Mix and stir the water-reducing agent, hydroxypropyl methylcellulose, sodium dodecyl sulfate and 80% water until they are evenly dissolved to obtain liquid A; Step 3: Mix calcium formate, aluminum sulfate, and triethanolamine with the remaining 20% ​​water and stir until dissolved to obtain liquid B; Step 4: Add white silicate cement and tailings sludge to a mixer and mix for 2 minutes to obtain dry material B; Step 5: Mix dry material B and dry material A in a mixer for 2 minutes; then add liquid A and mix for another 2 minutes; finally add liquid B and mix evenly to obtain inorganic stone paint.

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