A method for preparing multi-stage calcined kaolin by suspending calcination of coal series kaolin

Abstract

A method for preparing multi-stage calcined kaolin by suspending and calcining coal-based kaolin, comprising the following steps: (1) crushing and grinding the coal-based kaolin; (2) transporting the kaolin to a suspension dehydration calciner and heating it to 200-300° C. for dehydration reaction, The dehydration material is formed and discharged; (3) enters the first cyclone separator for separation and enters the suspension dehydroxylation calciner, is heated to 700-900°C for dehydroxylation reaction, and forms the dehydration material to be discharged; (4) enters the second cyclone separator After separation, enter the suspension decarburization calciner, carry out decarburization reaction at 850-950°C, and discharge the decarbonized material; (5) enter the third cyclone separator and enter the cooler after separation, the temperature drops to 150-250°C and discharges; (6) ) through the first-stage cyclone classifier, the second-stage cyclone classifier and the third-stage cyclone classifier in turn to separate the first-stage calcined kaolin, the second-stage calcined kaolin and the third-stage calcined kaolin respectively. The invention has simple technological process, stable equipment and system operation, large processing capacity, low energy consumption and cost, and uniform product properties.

Description

technical field [0001] The invention belongs to the technical field of mineral processing, and in particular relates to a method for preparing multistage calcined kaolin by suspending and calcining coal series kaolin. Background technique [0002] Kaolin is an important industrial basic raw material, which can be widely used in many industries, such as ceramics, papermaking, coatings, plastics, rubber, building materials, etc.; as the consumption of kaolin continues to increase, there are fewer and fewer refined raw kaolin that meet industrial requirements , It is of great significance to develop and utilize new kaolin resources. Coal-measure kaolin has the characteristics of large reserves, wide distribution, and stable ore seams, and its kaolin content is often above 90%, which is a high-quality kaolin resource; but due to technical reasons, coal-measure kaolin has not been fully utilized; coal-measure kaolin Kaolin products have problems such as poor uniformity and white...

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Problems solved by technology

[0003] Patent CN201210311548.9 discloses a gaseous suspension calcination method of coal-based kaolin, which proposes to use gas to make the coal-based kaolin violently fluidized in the furnace for calcination. According to product requirements, the calcination temperature is controlled at 600-1400°C. The material is further whitened through the reburning heat exchange system outside the furnace. Compared with the traditional static calcination, this method has higher efficiency and larger processing capacity, but dehydroxylation and decarburization calcination are carried out at the same time. The pressure drop will lead to incomplete combustion of organic matter and carbon deposition, resulting in a decrease in the whiteness of the product, so further whitening treatment is required

Patent CN201510755157.X discloses a whitening method of coal-based kaolin, which proposes to mix coal-based kaolin powder with charcoal powder with a fineness of more than 2000 mesh, and then calcine and keep warm after mixing. ~4 hours, natural cooling, this method realizes the whitening of coal series kaolin, but it can only reach 85-90%, which cannot meet the needs of the paper industry, etc., and additional charcoal powder needs to be added, the process is complicated and the cost is high; there is calcination Long holding time, poor product uniformity, low processing capacity and low heat utilization efficiency

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