Method for producing precise foundry sand from high-aluminum coal ash

A high-aluminum fly ash and precision casting technology, which is applied in the field of waste resource utilization, can solve problems such as low thermal expansion rate, and achieve the effects of low water absorption rate, wide source and cheap raw materials

Active Publication Date: 2017-09-26
INST OF PROCESS ENG CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Aiming at the deficiencies in the prior art, the object of the present invention is to provide a method for producing precision casting sand using high-alumina fly ash, the precision casting sand obtained by the method has good fluidity, high refractoriness, high strength, thermal expansion It not only solves the problem of raw materials in the production process of precision casting sand, but also successfully handles industrial solid waste, achieving the purpose of turning waste into treasure, and has good economic and social value.

Method used

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  • Method for producing precise foundry sand from high-aluminum coal ash

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Experimental program
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Effect test

Embodiment 1

[0073] The method for producing precision casting sand by utilizing high alumina fly ash comprises the following steps:

[0074] The high alumina fly ash is purified according to the process of acid activation-desiliconization-dilute pickling. The acid activation conditions are: acid concentration 250g / L, activation temperature 70°C, activation time 2h, activation liquid-solid ratio 5mL / g; desiliconization conditions: alkali concentration 180g / L, desiliconization temperature 90°C, desiliconization time 60min, desiliconization liquid-solid ratio 5mL / g; dilute pickling conditions: washing temperature 60°C, washing time 50min , the mass ratio of the first washing liquid to the second solid is 3. The mass percent content of prepared alumina is 65%, ω[(Na, K) 2 O] is 0.5% high-purity fly ash powder, granulated in the swing granulator, and then sieved in the sieving machine, the particles greater than 10 meshes are the primary particles, and the fine particles are granulated in a ...

Embodiment 2

[0076] The method for producing precision casting sand by utilizing high alumina fly ash comprises the following steps:

[0077] The high alumina fly ash is purified according to the process of acid activation-desiliconization-dilute pickling. The acid activation conditions are: acid concentration 260g / L, activation temperature 90°C, activation time 2h, activation liquid-solid ratio 4mL / g; desiliconization conditions: alkali concentration 200g / L, desiliconization temperature 90°C, desiliconization time 70min, desiliconization liquid-solid ratio 5mL / g; dilute pickling conditions: washing temperature 70°C, washing time 40min , the mass ratio of the first washing liquid to the second solid is 3. The mass percent content of prepared alumina is 68%, ω[(Na, K) 2 O] is 0.5% high-purity fly ash powder, granulated in the swing granulator, and then sieved in the sieving machine, the particles greater than 10 meshes are the primary particles, and the fine particles are granulated in a ...

Embodiment 3

[0079] The method for producing precision casting sand by utilizing high alumina fly ash comprises the following steps:

[0080]The high alumina fly ash is purified according to the process of acid activation-desiliconization-dilute pickling. The acid activation conditions are: acid concentration 270g / L, activation temperature 85°C, activation time 2h, activation liquid-solid ratio 4mL / g; desiliconization conditions: alkali concentration 200g / L, desiliconization temperature 95°C, desiliconization time 70min, desiliconization liquid-solid ratio 5mL / g; dilute pickling conditions: washing temperature 80°C, washing time 40min , the mass ratio of the first washing liquid to the second solid is 4. The mass percent content of prepared alumina is 66%, ω[(Na, K) 2 O] is 0.45% high-purity fly ash powder, granulated in the swing granulator, and then sieved in the sieving machine, the particles greater than 10 meshes are the primary particles, and the fine particles are granulated in a ...

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Abstract

The invention provides a method for producing precise foundry sand from high-aluminum coal ash. The method comprises the following steps of: purifying high-aluminum coal ash, pelletizing, drying, roasting and post-treating the purified high-aluminum coal ash to obtain the precise foundry sand, wherein the step of purifying the precise foundry sand adopts an acid activation-alkali desilicication-diluted acid washing process. The precise foundry sand obtained by the method has the advantages of good mobility, high refractoriness, high strength, a low thermal expansion coefficient, good sand sticking resistance, solves the raw material problem in a production process of the precise foundry sand, successfully treats industrial solid waste, achieves the purpose of changing waste into things of value, and has a good economic and social value.

Description

technical field [0001] The invention belongs to the technical field of resource utilization of waste, and relates to a method for producing precision casting sand by using fly ash. Background technique [0002] High-alumina fly ash is a solid waste produced by burning high-alumina coal in thermal power plants in central Inner Mongolia and northern Shanxi. It contains a large amount of resources such as alumina and silica. Currently, the utilization rate is low, and a large amount of unused High aluminum fly ash not only pollutes the environment but also causes a huge waste of resources. [0003] Foundry sand is a granular refractory material used in the metal casting process. The particle shape and grading of foundry sand have an important impact on its fluidity, compactness, air permeability, strength and resistance to liquid metal penetration. The foundry sand currently used is mainly silica sand with silica as the main component and quartz as the main crystal phase, as ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22C5/00B22C1/00
CPCB22C1/00B22C5/00
Inventor 李占兵李会泉李少鹏
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
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