SU1721010A1 - Method of sintering phosphorite fines - Google Patents

Abstract

The invention relates to the phosphorus industry and can be used in the technology of the agglomeration of phosphate raw materials. The aim of the invention is to increase the specific productivity of the process, the yield of the product and its mechanical strength. The method consists in mixing phosphate fines, returning and coke, moistening the mixture with an aqueous suspension containing 0.3-0.7 May. % kaolin and up to 0.5 May. % fatty acid carbon atoms of at least 21, pelletizing the mixture, ignition of coke and sintering, followed by separation of the product fraction plus 6 mm. 1 hp f-ly, 2 tab.

Description

The invention relates to agglomeration and thermal preparation of fine fractions of phosphate ore for the electrothermal production of phosphorus and can be used in the phosphorus industry.

The purpose of the invention. is to increase the specific productivity of the process, the yield of the product and its mechanical strength.

PRI me R. 30 kg of the mixture, containing 67.8% of phosphorite fines, 20.5% of return and 5.1% of coke, are moistened in the granulator with 2.1 kg of suspension of kaolin in a 0.5% aqueous solution of fatty acids and for 3 min granulated. The content of kaolin in suspension 0.7 wt.%. The optimum moisture content of the charge before sintering is 6-8%. The resulting mixture is loaded into the aglochash and dried at 250-300 ° C for 2-3 minutes. Then, the mixture is heated to the ignition temperature of coke (800-850 ° C) and after that the supply of natural gas to the hotplates is stopped. The sintering of the charge occurs due to the burning of coke for 18-20 minutes. The temperature in the layer of the mixture reaches 1300 ° C. Upon completion, the sintering process is cooled and the product of the fraction plus 6 mm is isolated. The yield of the product is 83.6%, the compressive strength is 304.1 kg / pc, the specific process capacity is 0.715 t / m2.h.

In tab. Figure 1 shows the dependence of the process indicators on the kaolin content in the suspension. As can be seen from the table. 1, when using a suspension of kaolin below 0.3 wt.%, The agglomeration indicators (yield of a suitable fraction, strength) decrease, and an increase in concentration above 0.7 May. % is impractical because the agglomeration indicators do not noticeably improve,

In tab. 2 shows the values of the process indicators when used for wetting various combinations of components

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moisture, as well as comparative data by a known method.

As can be seen from the table. 2, the proposed method makes it possible to increase the specific productivity by 12% (of the process and by | 13% the yield of the product and almost twice its mechanical strength.

As a fatty acid, the product of saponification of the bottoms from the oxidative processing of paraffins containing C21 and higher carbon atoms is used.

An increase in the concentration of fatty acids in an aqueous solution from 0 to 0.5 wt.% Leads to an increase in material clodiness and an increase in the agglomeration during subsequent calcination, and an increase in the concentration of fatty acids in excess of 0.5 wt.% Is impractical, because it is not

leads to a noticeable improvement in agglomeration indicators.

FORUMAWLAH AND ISLANDS

Claims (2)

1. Method of agglomeration of phosphoric fines, including its mixing with return and coke, moistening the kaolin with an aqueous suspension, granulation and sintering the resulting mixture, followed by separation of the product fractions plus 6 mm, in order to increase the yield, product and its mechanical strength kaolin aqueous suspension is used with a concentration of 0.3-0.7 wt.% and fatty acids are additionally introduced into it. the number of carbon atoms is not less than 21. 2. The method according to claim 1. characterized in that the fatty acids are administered in an amount that ensures their concentration in the suspension is up to 0.5 May. % Table 1 the charge (1% by weight charge) 0 ,, 569,5 Moisturizing blend 1 & aq. Kaolin water suspension (known method) 0.63 161, 72.5 Moisturize the mixture with kaolin suspension in an aqueous solution of polycrylamide 0.66 168.5 72.5 Moisturizing the blend with kaolin suspension in a solution of partially saponified polyvinyl acetate O. bA 161.8 70.6 Moisturize batch sus-. kaolin pension in a liquid glass solution of 0.67 171.0, 0 Moisturizing the mixture with kaolin suspension in an aqueous solution of humates: sodium 0.65 163.8 72.6 Moisturizing the mixture with kaolin suspension in an aqueous solution of sulphate liquor 0., 63 71.1 Moisturizing the mixture with kaolin suspension in an aqueous solution of ferrous sulfate 0.6 159.7 69.8 Moisturizing the mixture with a suspension of kaolin in an aqueous solution of fatty acids (the proposed method) 0,71530,183,6