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CN-122010486-A - Preparation method of coal gasification slag concrete

CN122010486ACN 122010486 ACN122010486 ACN 122010486ACN-122010486-A

Abstract

The invention relates to the technical field of concrete and discloses a method for preparing coal gasification slag concrete, which comprises the steps of mixing stone, sand and coal gasification slag mixed fine aggregate, cementing material, composite activator and water, wherein the total mass of the stone, the sand and coal gasification slag mixed fine aggregate, the cementing material, the composite activator and the water is 100 parts, the use amounts of the stone, the sand and coal gasification slag mixed fine aggregate, the cementing material, the composite activator and the water are 40-45 parts, 24-40 parts, 15-22 parts, 1-5 parts and 5-10 parts respectively, the coal gasification slag mass is 35-65% of the sand and coal gasification slag mixed fine aggregate mass, and the composite activator comprises CaO-based early strength agent, phosphogypsum, lithium salt and alkali solution. The invention greatly improves the compactness of the concrete matrix, thereby effectively improving the mechanical property and durability index of the concrete, and particularly remarkably improving the compressive strength and the chloride ion permeation resistance.

Inventors

  • CHEN PENG
  • YUAN QIAN
  • LI BO
  • WANG XIAOLI

Assignees

  • 国家能源集团宁夏煤业有限责任公司
  • 宁夏煤炭基本建设有限公司

Dates

Publication Date
20260512
Application Date
20260116

Claims (10)

  1. 1. A method of preparing coal gasification slag concrete, the method comprising: Mixing stones, sand, coal gasification slag, cementing materials, a composite activator and water, wherein: The method comprises the following steps that the total mass of stones, sand, coal gasification slag, cementing materials, compound excitant and water is 100 parts, the amounts of the stones, the mixture of the sand and the coal gasification slag, the cementing materials, the compound excitant and the water are 40-45 parts, 12-40 parts, 8-22 parts, 1-5 parts and 5-10 parts respectively, the mass of the coal gasification slag is 35-65% of the mass of mixed fine aggregate of the sand and the coal gasification slag, and the compound excitant comprises CaO-based early strength agent, phosphogypsum, lithium salt and alkali solution; The grain composition of the coal gasification furnace slag comprises less than or equal to 10% of screen residue of a 4.75mm square sieve, less than or equal to 25% of screen residue of a 2.36mm square sieve, 10-50% of screen residue of a 1.18mm square sieve, 41-70% of screen residue of a 600 mu m square sieve, 70-92% of screen residue of a 300 mu m square sieve and 90-100% of screen residue of a 150 mu m square sieve; The grain composition of the sand comprises the screen residue of 4.75mm square sieves which is less than or equal to 5%, the screen residue of 2.36mm square sieves which is less than or equal to 25%, the screen residue of 1.18mm square sieves which is 10-50%, the screen residue of 600 mu m square sieves which is 41-70%, the screen residue of 300 mu m square sieves which is 70-92% and the screen residue of 150 mu m square sieves which is 80-94%.
  2. 2. The method according to claim 1, wherein the amount of the fine aggregate of the stone, the mixed fine aggregate of the sand and the coal gasification slag, the cementing material, the composite activator and the water is 42 to 44 parts, 25 to 30 parts, 18 to 20 parts, 2 to 4 parts and 6 to 9 parts, respectively, based on the mass of the lithium salt being 1 part and the total mass of the fine aggregate of the stone, the sand and the coal gasification slag, the cementing material, the composite activator and the water being 100 parts.
  3. 3. The method according to claim 1 or 2, wherein the amount of the CaO-based early strength agent is 5 to 16 parts by mass of the lithium salt, the amount of the phosphogypsum is 10 to 30 parts by mass, the amount of the alkali solution is 3 to 10 parts by mass, and the concentration of the alkali in the alkali solution is 8 to 12mol/L.
  4. 4. A method according to any one of claims 1 to 3, wherein the cementitious material is portland cement.
  5. 5. The method of any one of claims 1-4, wherein the alkaline solution comprises at least one of a sodium hydroxide solution and a potassium hydroxide solution.
  6. 6. The method of any one of claims 1-5, wherein the lithium salt comprises at least one of Li 2 CO 3 and LiCl.
  7. 7. The method according to any one of claims 1-6, characterized in that the specific process of the method comprises: s1, mixing CaO-based early strength agent, phosphogypsum, lithium salt and alkali solution to obtain a composite activator solution; And step S2, mixing the composite activator solution with coal gasification furnace slag, cementing material, sand, stones and water.
  8. 8. The method according to claim 7, wherein the mixing condition in the step S1 comprises a stirring speed of 150-250 r/min and a stirring time of 20-50S.
  9. 9. The method according to claim 7 or 8, wherein the specific process of step S2 comprises mixing the composite activator solution with the cementitious material, coal gasification slag and a portion of water, sequentially adding sand and stone, mixing, and finally adding the remaining water, mixing.
  10. 10. The method according to any one of claims 7 to 9, wherein in step S2, the mixing conditions include a stirring speed of 50 to 55r/min and a stirring time of 100 to 150S.

Description

Preparation method of coal gasification slag concrete Technical Field The invention relates to the technical field of concrete, in particular to a preparation method of coal gasification slag concrete. Background The 'two carbon' strategy in China is a profound and significant measure for influence, aims to actively cope with global climate change challenges, and promotes the development of the economic society to be comprehensively and environmentally-friendly. Under the macro strategic framework, the realization of the resource utilization of a large amount of solid wastes becomes an unprecedented rigidity requirement. The method is not only related to the efficient recycling of resources, but also is one of key paths for reducing environmental pollution and carbon emission, and has irreplaceable important roles for constructing a resource-saving and environment-friendly society. The production of building materials by utilizing coal gasification slag is a main research direction of clean utilization and sustainable development of coal at present, in the prior art, bricks, test blocks, cement or concrete doping and the like are mainly carried out based on the aggregate action and pozzolanic effect of low-carbon coal gasification slag, but when the coal gasification slag is practically applied to the production of building materials, some technical problems still exist, such as poor durability of concrete based on the coal gasification slag. Disclosure of Invention The invention aims to solve the problem of poor durability of concrete based on coal gasification slag in the prior art, and provides a preparation method of coal gasification slag concrete, which has high strength and good durability. In order to achieve the above object, the present invention provides in one aspect a method for preparing coal gasification slag concrete, the method comprising: Mixing fine aggregate of stone, sand and coal gasification slag, cementing material, compound excitant and water, wherein: The method comprises the following steps that based on the total mass of 100 parts of mixed fine aggregate of stones, sand and coal gasification slag, cementing materials, compound excitant and water, the amounts of the mixed fine aggregate of stones, sand and coal gasification slag, cementing materials, compound excitant and water are 40-45 parts, 24-40 parts, 15-22 parts, 1-5 parts and 5-10 parts respectively, the mass of the coal gasification slag is 35-65% of the mass of the mixed fine aggregate of sand and coal gasification slag, and the compound excitant comprises CaO-based early strength agent, phosphogypsum, lithium salt and alkali solution; The grain composition of the coal gasification furnace slag comprises less than or equal to 10% of screen residue of a 4.75mm square sieve, less than or equal to 25% of screen residue of a 2.36mm square sieve, 10-50% of screen residue of a 1.18mm square sieve, 41-70% of screen residue of a 600 mu m square sieve, 70-92% of screen residue of a 300 mu m square sieve and 90-100% of screen residue of a 150 mu m square sieve; The grain composition of the sand comprises the screen residue of 4.75mm square sieves which is less than or equal to 5%, the screen residue of 2.36mm square sieves which is less than or equal to 25%, the screen residue of 1.18mm square sieves which is 10-50%, the screen residue of 600 mu m square sieves which is 41-70%, the screen residue of 300 mu m square sieves which is 70-92% and the screen residue of 150 mu m square sieves which is 80-94%. Preferably, the total mass of the mixed fine aggregate of the stone, the sand and the coal gasification slag, the cementing material, the compound excitant and the water is 100 parts, and the use amounts of the mixed fine aggregate of the stone, the sand and the coal gasification slag, the cementing material, the compound excitant and the water are 42-44 parts, 25-30 parts, 18-20 parts, 2-4 parts and 6-9 parts respectively. Preferably, the mass of the lithium salt is 1 part, the dosage of the CaO-based early strength agent is 5-16 parts, the dosage of the phosphogypsum is 10-30 parts, and the dosage of the alkali solution is 3-10 parts. Preferably, the cementitious material is portland cement based on 100% total mass of sand and coal gasification slag. Preferably, the alkali solution includes at least one of a sodium hydroxide solution and a potassium hydroxide solution. Preferably, the lithium salt includes at least one of Li 2CO3 and LiCl. Preferably, the specific process of the method comprises: s1, mixing CaO-based early strength agent, phosphogypsum, lithium salt and alkali solution to obtain a composite activator solution; And step S2, mixing the composite activator solution with cementing materials, coal gasification furnace slag, sand, stones and water. Preferably, the mixing condition in the step S1 comprises the stirring speed of 150-250 r/min and the stirring time of 20-50S. Preferably, the specific process of the step S2