Active powder based on coal chemical by-products and its preparation method and application

Abstract

The present invention discloses an active powder based on coal chemical by-products, and its preparation method and application. The active powder based on coal chemical by-products of the present invention comprises the following components in parts by mass: activated gasification fine ash: 60 to 75 parts; enhanced regulator: 1.5 to 3 parts; dispersed regulator: 0.4 to 1 part; calcium-containing powder: 25 to 40 parts. The preparation method of the active powder based on coal chemical by-products of the present invention comprises the following steps: mixing the calcium-containing powder and the enhanced regulator, then adding the dispersed regulator and then ball milling, then adding the activated gasification fine ash and mixing, thereby obtaining the active powder based on coal chemical by-products. The active powder based on coal chemical by-products of the present invention has the advantages of high hydration activity, adjustable performance, simple preparation process, etc. It has a large dosage for cement concrete, good comprehensive effect, high adaptability, and is suitable for large-scale promotion and application.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial solid waste resource utilization, and in particular to an active powder based on coal chemical by-products, and a preparation method and application thereof. Background Art

[0002] Cement concrete is the most important structural engineering material and the largest man-made material in the modern world. Humanity's industrialization is inseparable from the support of cement concrete-based infrastructure and construction. However, in today's world where resource conservation and environmental protection are emphasized, the traditional extensive growth of the cement concrete production industry, which disregards environmental and resource costs, is facing increasing restrictions. Cement is the primary binder in cement concrete. Using industrial solid waste to partially or completely replace cement not only achieves resource utilization but also aligns with the sustainable development concept of green concrete.

[0003] Currently, the use of industrial waste residues (such as fly ash, granulated blast furnace slag, phosphorus slag, and steel slag) as supplementary cementitious materials for concrete mixing to reduce cement clinker usage has become widely accepted and applied. From a demand perspective, the current large-scale infrastructure construction, coupled with the need to construct new and complex structures, is driving an increasing demand for supplementary cementitious materials (especially high-quality ones). From a supply perspective, amidst industrial transformation and upgrading and the new energy revolution, the types and sources of commonly used, stable bulk solid wastes, such as power plant fly ash, will undergo significant changes, potentially leading to future scarcity. Furthermore, industrial transformation and upgrading are accompanied by the generation of new, typical, and difficult-to-treat industrial waste residues (such as circulating fluidized bed fly ash, lithium slag, and coal gasification slag). Therefore, given this supply-demand imbalance, typical, difficult-to-treat solid wastes with potential pozzolanic activity need to be considered for inclusion in the building materials industry.

[0004] Coal gasification slag is a typical difficult-to-treat solid waste, containing a high concentration of silicon and aluminum active substances. While it has potential for pozzolanic activity, its unique carbon-ash structure results in limited utilization. Coal gasification slag is divided into coarse gasification slag and fine gasification ash based on the discharge method of industrial waste. Coarse gasification slag has a relatively low carbon content and can be readily utilized after simple treatment. However, fine gasification ash contains a large amount of residual carbon on the ash surface, which is difficult to remove and has low activity, making its treatment and disposal a major challenge.

[0005] The building materials industry uses large amounts of industrial solid waste from other industries as a supplementary cementitious material to replace cement, thereby saving costs and reducing the industry's carbon emissions. This typically requires that the performance of the cementitious material or concrete after replacing some of the cement (especially early workability and strength after setting and hardening) should not be significantly reduced. Due to its high carbon content (25% to 50%), adding aerated fine ash directly to cement will absorb a large amount of water, seriously affecting the cement's early mixing process and reducing the strength after hardening, severely restricting its use as a supplementary cementitious material in cement concrete.

[0006] Therefore, there is an urgent need to find a method that can realize the large-scale application of gasified fine ash in the cement concrete industry. Summary of the Invention

[0007] The purpose of the present invention is to provide an active powder based on coal chemical by-products and a preparation method and application thereof.

[0008] The technical solution adopted by the present invention is:

[0009] An active powder based on coal chemical by-products, comprising the following components in parts by weight:

[0010] Active gasification fine ash: 60 to 75 parts;

[0011] Enhanced regulator: 1.5 to 3 parts;

[0012] Dispersing regulator: 0.4 to 1 part;

[0013] Calcium powder: 25 to 40 parts.

[0014] Preferably, the median particle size D of the activated gasification fine ash is 50 The particle size is 7 μm±1 μm, and the mass percentage of particles with a particle size of 2 μm to 20 μm is greater than 80%.

[0015] Preferably, the activated gasification fine ash has a carbon content of less than 3% and a water content of less than 3%.

[0016] Preferably, the activated gasified fine ash is prepared by subjecting gasified fine ash to microwave activation.

[0017] Further preferably, the activated gasification fine ash is prepared by the following method: the gasification fine ash is crushed and then wet-screened, and then filtered until no obvious water is precipitated, and then placed in a container made of absorbing material and placed in a microwave push plate kiln for microwave activation, and then discharged and rapidly air-cooled until the powder temperature is 40°C to 60°C higher than room temperature, thereby obtaining the activated gasification fine ash.

[0018] Preferably, the gasification fine ash comes from the black water precipitate after the crude synthesis gas in the coal gasification technology is washed and purified and then subjected to filter press treatment. The main components are amorphous silicon oxide and aluminum oxide minerals, accounting for 45% to 65% of the total mass, and also contain carbon components, accounting for 25% to 40% of the total mass, and also contain calcium oxide and iron oxide, accounting for 10% to 25% of the total mass.

[0019] Preferably, the particle size of the gasified fine ash after wet screening is less than 0.1 mm.

[0020] Preferably, the absorbing material is one or more of silicon carbide, manganese dioxide, and ferrosoferric oxide.

[0021] Preferably, the microwave activation is carried out under the conditions of microwave power of 800W to 1200W and temperature of 550°C to 575°C.

[0022] Preferably, the enhanced regulator is prepared by evaporating and crystallizing coal chemical wastewater that has undergone COD treatment.

[0023] Preferably, the COD value of the coal chemical wastewater treated with COD is ≤30 mg / L, the pH value is 7-9.5, the ammonia nitrogen content is <5 mg / L, and the salt content is ≥4000 mg / L.

[0024] Preferably, the enhanced regulator contains Ca 2+ , K + 、Na + 、SO4 2- and Cl - , and SO4 2- 、Cl - The molar ratio is 1:0.4~2.5.

[0025] Preferably, the dispersion type regulator comprises triethanolamine, polyaspartic acid and naphthalenesulfonate formaldehyde condensate.

[0026] Further preferably, the dispersed regulator comprises the following components in parts by mass:

[0027] Triethanolamine: 3 to 6 parts;

[0028] Polyaspartic acid: 20 to 40 parts;

[0029] Naphthalenesulfonate formaldehyde condensate: 5 to 10 parts;

[0030] Water: 50 to 80 parts.

[0031] Preferably, the polyaspartic acid has a weight average molecular weight of ≥14,000 and has amide and polyether side chains.

[0032] Preferably, the dispersed regulator is in a solution state with a solid content of 20% to 50%.

[0033] Preferably, the calcium-containing powder comprises slag powder, carbide slag and desulfurization gypsum.

[0034] Further preferably, the calcium-containing powder comprises the following components in parts by mass:

[0035] Slag powder: 90 to 98 parts;

[0036] Carbide slag: 1 to 5 parts;

[0037] Desulfurization gypsum: 1 to 5 parts.

[0038] Preferably, the slag powder is industrial solid waste slag formed by quenching and granulating a melt containing calcium aluminosilicate as a main component when smelting pig iron in a blast furnace in an ironmaking plant.

[0039] Preferably, the carbide slag is waste slag with calcium hydroxide as the main component formed after acetylene gas is obtained by hydrolysis of carbide in the coal chemical industry chain.

[0040] Preferably, the desulfurization gypsum is the flue gas desulfurization gypsum recovered from the slurry discharged from the absorption tower of the desulfurization device in the factory after passing through a dehydration device, and its main component is calcium sulfate dihydrate.

[0041] Preferably, the median particle size D of the calcium-containing powder is 50 <30μm, water content <3%.

[0042] A method for preparing the active powder based on coal chemical byproducts as described above comprises the following steps: mixing the calcium-containing powder and the enhancing regulator, adding the dispersing regulator and then ball milling until the specific surface area of the powder is 400 m 2 / kg~560m 2 / kg, and then add activated gasification fine ash and mix well to obtain activated powder based on coal chemical by-products.

[0043] A cement concrete comprises the above-mentioned active powder based on coal chemical by-products.

[0044] The beneficial effects of the present invention are as follows: the active powder based on coal chemical by-products has the advantages of high hydration activity, adjustable performance, simple preparation process, etc., is used in a large amount of cement concrete, has good comprehensive effects, and is highly adaptable, and is suitable for large-scale promotion and application.

[0045] Specifically:

[0046] 1) The active powder based on coal chemical byproducts of the present invention has high hydration activity and can be used in large amounts in cement concrete. The resulting cement concrete has advantages such as high early and late strength and good overall effect. This overcomes the problem of slow strength development and low early strength of traditional industrial waste residues as auxiliary cementitious materials due to low early activity. It also solves the problem that gasified fine ash is difficult to use on a large scale in the building materials field due to its high carbon content.

[0047] 2) The present invention's activated powder based on coal chemical byproducts contains activated gasified fine ash, significantly reducing the adverse effects of residual carbon in the gasified fine ash, which hinders binder hydration and bonding, and degrades fluidity due to high water absorption. The original gasified fine ash contains loose, porous, lamellar carbon, smooth and rough spherical mineral particles, and amorphous flocculent structures attached to or independently of the spheres, all of which absorb a significant amount of water. However, after microwave activation, the residual carbon in the original gasified fine ash (which has high humidity, high carbon content, and relatively high iron content, making it a good microwave absorbing material) is partially reduced to ashing (residual carbon content <3%). , excess water vapor evaporates, amorphous silicate-alumina minerals (SiO2+Al2O3) are enriched (accounting for more than 60%), the total activity is improved, and it has hydration activity. It can be secondary stimulated to generate hydration products under the action of an alkaline environment dominated by cement, which is beneficial to improving the later activity of the auxiliary cementitious material; after the gasified fine ash is microwave-treated, air cooling measures are taken to achieve rapid cooling, which is beneficial for the amorphous or glassy aluminum silicate minerals in it to convert the unreleased heat energy into chemical energy for storage, thereby improving the potential chemical activity and making the prepared active gasified fine ash have considerable stability and reliability;

[0048] 3) The active powder based on coal chemical by-products of the present invention is added with an enhancing regulator and a dispersing regulator, both of which come from the coal chemical industry chain. They can improve the problems of increased water demand and reduced mechanical strength caused by residual trace carbon in the active powder, and adjust the working performance, mechanical properties and durability of the active powder after being added to cement-based materials, reflecting the concept of using local materials and turning waste into treasure; the enhancing regulator mainly plays the role of improving mechanical properties, and the key component is solid mixed salt and miscellaneous salt prepared from salt-containing wastewater of coal chemical industry. This type of salt is a difficult-to-treat solid waste and should not be directly discarded. The recycling and processing cost is relatively high, and special equipment is usually required for salt separation; the solid mixed salt is used as an enhancing regulator, and the ions dissolved after it is dissolved in water can participate in and promote the dissolution-precipitation process of the active powder during the hydration process, and the strength of the hardened matrix is enhanced by promoting the speed of the hydration reaction and the generation of hydration products, which is beneficial to resisting external erosion. , extending the life of the structure; the dispersing regulator mainly plays the role of improving working performance, among which the key component polyaspartic acid is a biodegradable water-soluble amino acid polymer with an amide bond similar to that of protein. It has great advantages as a dispersant for carbon components (such as carbon nanotubes), and the side chains are attached with amide and polyether functional groups, which can significantly improve the dispersion and stability of active powders in the slurry; the amino and hydroxyl functional groups in the organic additive triethanolamine can enable it to adsorb on the mineral surface, reduce the surface tension of the powder, and thus improve the problem of low grinding efficiency caused by agglomeration of fine particles during the grinding process, thereby improving the grinding efficiency, refining the particles and optimizing the particle grading; naphthalenesulfonate formaldehyde condensate as an anionic surfactant, its anionic properties, macromolecular configuration, naphthalenesulfonate groups and formaldehyde condensation groups and other dispersion mechanisms work synergistically to reduce the surface tension of carbon and ash, and improve the fluidity and uniformity of the slurry;

[0049] 4) The active powder based on coal chemical by-products of the present invention is added with calcium-containing powder composed of three kinds of calcium-based solid wastes, namely slag powder, carbide slag and desulfurized gypsum, which makes up for the deficiency of calcium-containing active minerals in the chemical composition of gasified fine ash to a certain extent; the active powder undergoes hydration reaction in an alkaline environment, and the amount and form of the generated hydration products depend on the content ratio of calcium and silicon elements in the minerals. Too low calcium-silicon ratio will affect the polymerization degree of the hydration products in the three-dimensional network structure; slag powder contains more than 95% of glass and minerals such as dicalcium silicate, calcium feldspar, wollastonite, etc., which is a highly active mineral admixture, supplements the total amount of calcium-containing minerals in the active powder, and has a good water-reducing effect, while improving the later strength of the hydrated cementitious material; the main component of carbide slag is calcium hydroxide, which can provide an additional alkaline environment for the hydration of gasified fine ash, and at the same time, carbide slag is also a calcium-containing substance, and its Ca 2+The introduction of participates in the dissolution-precipitation process of hydration products, and to a certain extent contributes to the formation of hydration products; the main component of desulfurized gypsum is dihydrate gypsum, and the sulfate ions it provides promote the formation of hydrated calcium silicate gel, and additional ettringite is generated. The two products are staggered and overlapped to form a dense spatial network skeleton, which improves the density, strength and durability of the material; the three calcium source substances give full play to their composite superposition effect. After a large number of experiments and repeated demonstrations, it was found that by adjusting the proportions of different components and the dosage of performance regulators, the performance of the active powder based on coal chemical by-products can be adjusted and controlled to meet or match the requirements of different cement concrete materials, thereby greatly improving its adaptability and application range;

[0050] 5) This invention fully embodies the concept of using waste to treat waste. All raw materials are sourced from the coal chemical industry chain, with industrial by-products accounting for the majority. This not only solves the problem of handling and disposing of gasified fine ash, a typical difficult-to-treat solid waste, thereby enhancing resource recycling, but also reduces the damage to the air and soil caused by in-situ storage of gasified fine ash. Furthermore, when used as an active powder to replace cement, it also helps reduce greenhouse gas emissions.

[0051] 6) The active powder based on coal chemical by-products of the present invention has a wide range of applications and is suitable for use in projects such as mine filling, road and airport runway subgrades, environmentally friendly building structures, and secondary structural components. The related engineering structure supporting facilities are beneficial to the construction of the upstream and downstream industrial chains of the coal chemical industry. DETAILED DESCRIPTION

[0052] The present invention will be further explained and illustrated below with reference to specific embodiments.

[0053] Example 1:

[0054] An active powder based on coal chemical by-products, the composition of which is shown in the following table:

[0055] Table 1 Composition of an active powder based on coal chemical by-products

[0056]

[0057]

[0058] Note:

[0059] The activated gasification fine ash is prepared by the following method: the gasification fine ash (derived from the black water precipitate obtained by washing and purifying the crude synthesis gas in the coal-to-gas technology and then subjected to filter press treatment, mainly composed of amorphous silicon oxide and aluminum oxide minerals, accounting for 45% to 65% of the total mass, and also containing carbon components, accounting for 25% to 40% of the total mass, and a small amount of calcium oxide and iron oxide, accounting for 10% to 25% of the total mass) is crushed and wet-screened to obtain a particle size of less than 0.1 mm after wet screening. The ash is then filtered until no obvious water is precipitated, and then placed in a bowl-shaped container made of silicon carbide and placed in a microwave push-plate kiln for activation for 60 minutes under conditions of a microwave power of 1200 W and a temperature of 550° C. The ash is then discharged and rapidly air-cooled until the powder temperature is 50° C. higher than room temperature, thereby obtaining the activated gasification fine ash.

[0060] Enhanced regulator: It is made by evaporation and crystallization of COD-treated coal chemical wastewater (COD value is 15 mg / L, pH value is 7.3, ammonia nitrogen content is 1 mg / L, and salt content is 10,000 mg / L).

[0061] Dispersed regulator: composed of triethanolamine, polyaspartic acid (weight average molecular weight of 19420, with amide and polyether side chains), naphthalenesulfonate formaldehyde condensate and water in a mass ratio of 3:35:9:53.

[0062] Calcium-containing powder: composed of slag powder (industrial solid waste slag formed by water quenching and granulation of the molten material with calcium aluminosilicate as the main component produced when the ironworks smelt pig iron in the blast furnace), carbide slag (waste slag with calcium hydroxide as the main component formed after acetylene gas is obtained by hydrolysis of calcium carbide in the coal chemical industry chain) and desulfurization gypsum (flue gas desulfurization gypsum recovered after the slurry discharged from the absorption tower of the desulfurization device in the factory passes through the dehydration device, and its main component is calcium sulfate dihydrate) in a mass ratio of 95:4:1.

[0063] The method for preparing the active powder based on coal chemical by-products comprises the following steps:

[0064] The calcium-containing powder and the enhanced regulator are mixed evenly, and then the dispersed regulator is evenly sprayed on the surface of the mixed powder and then transferred to the ball mill for ball milling until the powder has a specific surface area of 550m 2 / kg±10m 2 / kg, and then add activated gasification fine ash and mix evenly to obtain activated powder based on coal chemical by-products.

[0065] Example 2:

[0066] An active powder based on coal chemical by-products, the composition of which is shown in the following table:

[0067] Table 2 Composition of an active powder based on coal chemical by-products

[0068]

[0069]

[0070] Note:

[0071] The activated gasification fine ash is prepared by the following method: the gasification fine ash (derived from the black water precipitate obtained by washing and purifying the crude synthesis gas in the coal-to-gas technology and then subjected to filter press treatment, mainly composed of amorphous silicon oxide and aluminum oxide minerals, accounting for 45% to 65% of the total mass, and also containing carbon components, accounting for 25% to 40% of the total mass, and a small amount of calcium oxide and iron oxide, accounting for 10% to 25% of the total mass) is crushed and wet-screened to obtain a particle size of less than 0.1 mm after wet screening. The ash is then filtered until no obvious water is precipitated, and then placed in a bowl-shaped container made of silicon carbide and placed in a microwave push-plate kiln for activation for 60 minutes under conditions of a microwave power of 1200 W and a temperature of 550° C. The ash is then discharged and rapidly air-cooled until the powder temperature is 50° C. higher than room temperature, thereby obtaining the activated gasification fine ash.

[0072] Enhanced regulator: It is made by evaporation and crystallization of COD-treated coal chemical wastewater (COD value is 15 mg / L, pH value is 7.3, ammonia nitrogen content is 1 mg / L, and salt content is 10,000 mg / L).

[0073] Dispersing regulator: composed of triethanolamine, polyaspartic acid (weight average molecular weight of 19420, with amide and polyether side chains), naphthalenesulfonate formaldehyde condensate and water in a mass ratio of 4:32:8:56.

[0074] Calcium-containing powder: composed of slag powder (industrial solid waste slag formed by water quenching and granulation of the molten material with calcium aluminosilicate as the main component produced when the ironworks smelt pig iron in the blast furnace), carbide slag (waste slag with calcium hydroxide as the main component formed after acetylene gas is obtained by hydrolysis of calcium carbide in the coal chemical industry chain) and desulfurization gypsum (flue gas desulfurization gypsum recovered after the slurry discharged from the absorption tower of the desulfurization device in the factory passes through the dehydration device, and its main component is calcium sulfate dihydrate) in a mass ratio of 95:3:2.

[0075] The method for preparing the active powder based on coal chemical by-products comprises the following steps:

[0076] The calcium-containing powder and the enhanced regulator are mixed evenly, and then the dispersed regulator is evenly sprayed on the surface of the mixed powder and then transferred to the ball mill for ball milling until the powder specific surface area is 550m 2 / kg±10m 2 / kg, and then add activated gasification fine ash and mix evenly to obtain activated powder based on coal chemical by-products.

[0077] Example 3:

[0078] An active powder based on coal chemical by-products, the composition of which is shown in the following table:

[0079] Table 3 Composition of an active powder based on coal chemical by-products

[0080]

[0081]

[0082] Note:

[0083] The activated gasification fine ash is prepared by the following method: the gasification fine ash (derived from the black water precipitate obtained by washing and purifying the crude synthesis gas in the coal-to-gas technology and then subjected to filter press treatment, mainly composed of amorphous silicon oxide and aluminum oxide minerals, accounting for 45% to 65% of the total mass, and also containing carbon components, accounting for 25% to 40% of the total mass, and a small amount of calcium oxide and iron oxide, accounting for 10% to 25% of the total mass) is crushed and wet-screened to obtain a particle size of less than 0.1 mm after wet screening. The ash is then filtered until no obvious water is precipitated, and then placed in a bowl-shaped container made of silicon carbide and placed in a microwave push-plate kiln for activation for 60 minutes under conditions of a microwave power of 1200 W and a temperature of 550° C. The ash is then discharged and rapidly air-cooled until the powder temperature is 50° C. higher than room temperature, thereby obtaining the activated gasification fine ash.

[0084] Enhanced regulator: It is made by evaporation and crystallization of COD-treated coal chemical wastewater (COD value is 15 mg / L, pH value is 7.3, ammonia nitrogen content is 1 mg / L, and salt content is 10,000 mg / L).

[0085] Dispersing regulator: composed of triethanolamine, polyaspartic acid (weight average molecular weight of 19420, with amide and polyether side chains), naphthalenesulfonate formaldehyde condensate and water in a mass ratio of 5:32:7:56.

[0086] Calcium-containing powder: composed of slag powder (industrial solid waste slag formed by water quenching and granulation of the molten material with calcium aluminosilicate as the main component produced when the ironworks smelt pig iron in the blast furnace), carbide slag (waste slag with calcium hydroxide as the main component formed after acetylene gas is obtained by hydrolysis of calcium carbide in the coal chemical industry chain) and desulfurization gypsum (flue gas desulfurization gypsum recovered after the slurry discharged from the absorption tower of the desulfurization device in the factory passes through the dehydration device, and its main component is calcium sulfate dihydrate) in a mass ratio of 95:3:2.

[0087] The method for preparing the active powder based on coal chemical by-products comprises the following steps:

[0088] The calcium-containing powder and the enhanced regulator are mixed evenly, and then the dispersed regulator is evenly sprayed on the surface of the mixed powder and then transferred to the ball mill for ball milling until the powder specific surface area is 550m 2 / kg±10m2 / kg, and then add activated gasification fine ash and mix evenly to obtain activated powder based on coal chemical by-products.

[0089] Example 4:

[0090] An active powder based on coal chemical by-products, the composition of which is shown in the following table:

[0091] Table 4 Composition of an active powder based on coal chemical by-products

[0092]

[0093] Note:

[0094] The activated gasification fine ash is prepared by the following method: the gasification fine ash (derived from the black water precipitate obtained by washing and purifying the crude synthesis gas in the coal-to-gas technology and then subjected to filter press treatment, mainly composed of amorphous silicon oxide and aluminum oxide minerals, accounting for 45% to 65% of the total mass, and also containing carbon components, accounting for 25% to 40% of the total mass, and a small amount of calcium oxide and iron oxide, accounting for 10% to 25% of the total mass) is crushed and wet-screened to obtain a particle size of less than 0.1 mm after wet screening. The ash is then filtered until no obvious water is precipitated, and then placed in a bowl-shaped container made of silicon carbide and placed in a microwave push-plate kiln for activation for 60 minutes under conditions of a microwave power of 1200 W and a temperature of 550° C. The ash is then discharged and rapidly air-cooled until the powder temperature is 50° C. higher than room temperature, thereby obtaining the activated gasification fine ash.

[0095] Enhanced regulator: It is made by evaporation and crystallization of COD-treated coal chemical wastewater (COD value is 15 mg / L, pH value is 7.3, ammonia nitrogen content is 1 mg / L, and salt content is 10,000 mg / L).

[0096] Dispersing regulator: composed of triethanolamine, polyaspartic acid (weight average molecular weight of 19420, with amide and polyether side chains), naphthalenesulfonate formaldehyde condensate and water in a mass ratio of 6:32:6:56.

[0097] Calcium-containing powder: It is composed of slag powder (industrial solid waste slag formed by water quenching and granulation of the molten material with calcium silicate as the main component produced when the ironworks smelt pig iron in the blast furnace), carbide slag (waste slag with calcium hydroxide as the main component formed after acetylene gas is obtained by hydrolysis of calcium carbide in the coal chemical industry chain) and desulfurization gypsum (flue gas desulfurization gypsum recovered after the slurry discharged from the absorption tower of the desulfurization device in the factory passes through the dehydration device, and its main component is calcium sulfate dihydrate) in a mass ratio of 94:3:3.

[0098] The method for preparing the active powder based on coal chemical by-products comprises the following steps:

[0099] The calcium-containing powder and the enhanced regulator are mixed evenly, and then the dispersed regulator is evenly sprayed on the surface of the mixed powder and then transferred to the ball mill for ball milling until the powder specific surface area is 550m 2 / kg±10m 2 / kg, and then add activated gasification fine ash and mix evenly to obtain activated powder based on coal chemical by-products.

[0100] Comparative Example 1:

[0101] Fly ash (main chemical composition: SiO2 54.3wt%, Al2O3 28.1wt%, CaO 6.4wt%, Fe2O35.3wt%, Na2O 0.2wt%, MgO 2.6wt%, SO3 0.7wt%, LOI (loss on ignition) 1.6%, water content <3%, specific surface area 451m 2 / kg).

[0102] Comparative Example 2:

[0103] An active powder, the composition of which is shown in the following table:

[0104] Table 5 Composition of an active powder

[0105]

[0106] Note:

[0107] The activated gasification fine ash is prepared by the following method: the gasification fine ash (derived from the black water precipitate obtained by washing and purifying the crude synthesis gas in the coal-to-gas technology and then subjected to filter press treatment, mainly composed of amorphous silicon oxide and aluminum oxide minerals, accounting for 45% to 65% of the total mass, and also containing carbon components, accounting for 25% to 40% of the total mass, and a small amount of calcium oxide and iron oxide, accounting for 10% to 25% of the total mass) is crushed and wet-screened to obtain a particle size of less than 0.1 mm after wet screening. The ash is then filtered until no obvious water is precipitated, and then placed in a bowl-shaped container made of silicon carbide and placed in a microwave push-plate kiln for activation for 60 minutes under conditions of a microwave power of 1200 W and a temperature of 550° C. The ash is then discharged and rapidly air-cooled until the powder temperature is 50° C. higher than room temperature, thereby obtaining the activated gasification fine ash.

[0108] Calcium-containing powder: composed of slag powder (industrial solid waste slag formed by water quenching and granulation of the molten material with calcium aluminosilicate as the main component produced when the ironworks smelt pig iron in the blast furnace), carbide slag (waste slag with calcium hydroxide as the main component formed after acetylene gas is obtained by hydrolysis of calcium carbide in the coal chemical industry chain) and desulfurization gypsum (flue gas desulfurization gypsum recovered after the slurry discharged from the absorption tower of the desulfurization device in the factory passes through the dehydration device, and its main component is calcium sulfate dihydrate) in a mass ratio of 95:4:1.

[0109] The preparation method of the active powder comprises the following steps:

[0110] The activated gasification fine ash and calcium-containing powder are mixed evenly to obtain the activated powder.

[0111] Comparative Example 3:

[0112] An active powder, the composition of which is shown in the following table:

[0113] Table 6 Composition of an active powder

[0114]

[0115] Note:

[0116] The treatment process of gasification fine ash: the gasification fine ash (derived from the black water precipitate of the crude synthesis gas in the coal-to-gas technology after washing and purification and filter pressing, the main components of which are amorphous silicon oxide and aluminum oxide minerals, accounting for 45% to 65% of the total mass, and also contains carbon components, accounting for 25% to 40% of the total mass, and a small amount of calcium oxide and iron oxide, accounting for 10% to 25% of the total mass) is crushed and wet-screened. The particle size after wet screening is <0.1mm, and then filtered until no obvious water is precipitated. Then, the gasification fine ash is placed in a drying oven at 105°C for thorough drying to obtain the gasification fine ash.

[0117] Enhanced regulator: It is made by evaporation and crystallization of COD-treated coal chemical wastewater (COD value is 15 mg / L, pH value is 7.3, ammonia nitrogen content is 1 mg / L, and salt content is 10,000 mg / L).

[0118] Dispersed regulator: composed of triethanolamine, polyaspartic acid (weight average molecular weight of 19420, with amide and polyether side chains), naphthalenesulfonate formaldehyde condensate and water in a mass ratio of 3:35:9:53.

[0119] Calcium-containing powder: composed of slag powder (industrial solid waste slag formed by water quenching and granulation of the molten material with calcium aluminosilicate as the main component produced when the ironworks smelt pig iron in the blast furnace), carbide slag (waste slag with calcium hydroxide as the main component formed after acetylene gas is obtained by hydrolysis of calcium carbide in the coal chemical industry chain) and desulfurization gypsum (flue gas desulfurization gypsum recovered after the slurry discharged from the absorption tower of the desulfurization device in the factory passes through the dehydration device, and its main component is calcium sulfate dihydrate) in a mass ratio of 95:4:1.

[0120] The preparation method of the active powder comprises the following steps:

[0121] The calcium-containing powder and the enhanced regulator are mixed evenly, and then the dispersed regulator is evenly sprayed on the surface of the mixed powder and then transferred to the ball mill for ball milling until the powder has a specific surface area of 550m 2 / kg±10m 2 / kg, then add gasified fine ash and mix evenly to obtain active powder.

[0122] Performance testing:

[0123] The mortar fluidity and activity index of the powders of Examples 1 to 4 and Comparative Examples 1 to 3 were tested with reference to "GB / T 1596-2017 Fly ash for cement and concrete". The cement used in the test was PO42.5 cement and the sand was ISO standard sand. The test results are shown in the following table:

[0124] Table 7 Test results of mortar fluidity and activity index

[0125]

[0126] From Table 7 we can see that:

[0127] 1) The fluidity of the mortars made from the active powders of Examples 1 to 4 is very similar to that of the mortar made from fly ash of Comparative Example 1, and both can meet the fluidity requirements required for engineering construction. In addition, the mortars made from the active powders of Examples 1 to 4 have higher compressive strength and activity index.

[0128] 2) The mortars made with the active powder of Comparative Example 2 (without the addition of a performance regulator) and the active powder of Comparative Example 3 (with the gasified fine ash not activated) developed slowly in strength, while the mortars made with the active powders of Examples 1 to 4 showed obvious early strength characteristics, with the 28-day activity index exceeding 90%, demonstrating good application effects.

[0129] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. An active powder based on coal chemical by-products, characterized in that: The composition comprises the following components in parts by weight: Active gasification fine ash: 60 to 75 parts; Enhanced regulator: 1.5 to 3 parts; Dispersing regulator: 0.4 to 1 part; Calcium powder: 25 to 40 parts; The median particle size D of the activated gasification fine ash 50 The mass percentage of particles with a particle size of 7μm±1μm and a particle size of 2μm to 20μm is greater than 80%; The activated gasification fine ash has a carbon content of <3% and a water content of <3%; The activated gasified fine ash is made by subjecting gasified fine ash to microwave activation and air cooling; The gasification fine ash comes from the black water sediment after the crude synthesis gas in the coal gasification technology is washed and purified and then filtered. The main components are amorphous silicon oxide and aluminum oxide minerals, accounting for 45% to 65% of the total mass, and also contain carbon components, accounting for 25% to 40% of the total mass, and calcium oxide and iron oxide, accounting for 10% to 25% of the total mass. The enhanced conditioning agent is made by evaporating and crystallizing the coal chemical wastewater after COD treatment; The calcium-containing powder comprises slag powder, carbide slag and desulfurized gypsum.

2. The active powder based on coal chemical by-products according to claim 1, characterized in that: The activated gasification fine ash is prepared by the following method: the gasification fine ash is crushed and then wet-screened, then filtered until no obvious water is precipitated, then placed in a container made of a microwave-absorbing material, and then placed in a microwave push-plate kiln for microwave activation, and then discharged and rapidly air-cooled until the powder temperature is 40° C. to 60° C. higher than room temperature, thereby obtaining the activated gasification fine ash.

3. The active powder based on coal chemical by-products according to claim 2, characterized in that: The absorbing material is one or more of silicon carbide, manganese dioxide, and ferrosoferric oxide.

4. The active powder based on coal chemical by-products according to any one of claims 1 to 3, characterized in that: The microwave activation is carried out under the conditions of microwave power of 800W to 1200W and temperature of 550°C to 575°C.

5. The active powder based on coal chemical by-products according to any one of claims 1 to 3, characterized in that: The enhanced regulator contains Ca 2+ , K + 、Na + 、SO4 2- and Cl - , and SO4 2- 、Cl - The molar ratio is 1:0.4~2.

5.

6. The active powder based on coal chemical by-products according to any one of claims 1 to 3, characterized in that: The dispersion type regulator comprises triethanolamine, polyaspartic acid and naphthalenesulfonate formaldehyde condensate.

7. The active powder based on coal chemical by-products according to any one of claims 1 to 3, characterized in that: The median particle size D of the calcium-containing powder 50 <30μm, water content <3%.

8. A method for preparing active powder based on coal chemical by-products according to any one of claims 1 to 7, characterized in that: The process comprises the following steps: mixing calcium-containing powder and an enhancing regulator, adding a dispersing regulator, and then ball milling until the specific surface area of the powder is 400 m 2 / kg~560m 2 / kg, and then add activated gasification fine ash and mix well to obtain activated powder based on coal chemical by-products.

9. A cement concrete, characterized in that: The active powder based on coal chemical by-products comprises any one of claims 1 to 7.

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