SU1583352A1 - Method of sintering initial phosphate materials - Google Patents

Abstract

This invention relates to a process for preparing phosphate feedstock for the production of phosphorus by the electrothermal method. The aim of the invention is to increase the yield of the product. The method consists in mixing phosphate raw materials with solid fuels and carbonaceous shales, wetting and pelletizing the mixture, sintering it with sucking through a layer of a pelletized air mixture and cooling the cake with a gaseous agent containing not more than 8.1% by volume of oxygen and mono- and carbon dioxide with bulk their ratio, respectively, equal to 1: (1.8-2.2). At the same time, the waste gases from the sintering stage, formed between 13 and 15 minutes from the start of the sintering process, are used as the gaseous agent. 1 hp f-ly, 1 tab.

Description

This invention relates to the preparation of phosphate raw materials by agglomeration for electrothermal phosphorus production.

The aim of the invention is to increase the yield of the product.

PRI me R. Phosphate raw materials with a particle size of 0-10.0 mm of the following chemical composition, wt.% Are used as the ore component of the charge: P40ff 21.6; SiOa 21.4; CaO 36.8; MgO 2.43; A140S 1, Fe703 0.64; F 0.78; ppt 14.8; S 0.05.

Carboniferous shales have the following chemical composition, wt.%: Si04 52.6; A140E 2.0; ppt 20.0; Siel 15.0; Ug6do, 4; Na, 0 0.5; 0.3; Fe, pj 5.0; impurities 4.8.

As solid fuel, use is made of metallurgical coke fines with a particle size of 0-3 mm of the following composition, wt%: Snelet 80,98; ash 17.0; S 0.52; volatile 1.5.

27.54 kg (81%) of phosphorite, 1.70 kg (5%) of solid fuels and 4.76 kg (14%) of carbonaceous shale are mixed. The resulting mixture is moistened to a moisture content of 8.0% and pelletized on a plate granulator for 4 minutes. The pelletized mixture in the amount of 36.7 kg is loaded into an agglomeration bowl with a diameter of 400 mm and is sintered at a height of a loading layer of 230 mm; ignition mode: 1.5 min at 1250 ° C and a vacuum under the grate 300-500 mm water; Art .;

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thirty

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vacuum during sintering of 1000 mm of water. Art.

At the end of the process, the cake is cooled by gas with the following parameters: content 07 7.952; the ratio of CO: CO 1: 1.8. These parameters of the cooling gas correspond to the parameters of the agglomeration flue gases for 13 minutes from the start of the process.

After the end of the experiment, the following results are obtained: a spec. Mass of 27.9 kg; the usable sinter weight is determined according to the standard procedure) 24.4 kg, the residual carbon content is 1.8%, the process time is 21 min, the yield of the sinter is 0.55 t / m.h.

During the sintering process, the solid fuel of the charge does not burn out completely, and part of the residual carbon in the cooling zone of the sinter re-ignites when the cooling air interacts with oxygen, which leads to the appearance of microcracks in the finished product and, as a result, an increase in the amount of fines generated, t. e. to a reduction in yield. At the same time, the residual carbon content in the agglomerate decreases, i.e. carbon is lost, which could be used on the subsequent electric smelting,

The table presents data on the yield of the product, depending on the parameters of the cooling gaseous refrigerant.

As can be seen from the table, when the oxygen content in the gaseous refrigerant is more than 8.1%, the outbreak of residual carbon and a decrease in product yield occur.

When the content of C0g in the aglogas 45 is less than 158 per unit CO, the reaction-reaction CO + 0.5 O g with

0

five

five

about

five

0

five

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the formation of carbon black, which is ignited, and the release of oxygen and the increase in temperature also contribute to the burning of residual carbon and a decrease in product yield.

The C0rH content of aglogas over 2.2 per CO unit leads to a noticeable development of the CO2 + reaction, the flow of which in the finished sinter layer as well as the ignition of residual carbon causes the appearance of microcracks and a decrease in the yield of the suitable product.

Claims (2)

1. A method of agglomerating phosphate raw materials, including mixing it with solid fuel and carbonaceous shale, moistening and pelletizing the mixture, sintering it with sucking through the layer of the pelletized air mixture and cooling the cake with a gaseous agent, characterized in that to increase the yield of the product, for cooling, a gaseous agent containing not more than 8.1% by volume of oxygen and carbon mono- and carbon dioxide at a volume ratio of 1: (1.8-2.2), respectively, is used. 2. Method pop. 1, differing from that by the fact that the gases from the sintering stage, formed between 13 and 15 min of the beginning of the process of sintering. 6 (famous ) Air 0.6 0.53