Electric furnace phosphorus preparation method

Abstract

The invention discloses an electric furnace phosphorus preparation method, comprising phosphorite pretreatment and phosphorus preparation in a furnace, wherein the phosphorite pretreatment comprises steps of: mixing phosphorite powder with a binder to obtain mixed ore powder; pressing the mixed ore powder into pellets; performing first high temperature roasting and cementing on the pellets to obtain pretreatment pellets. The phosphorus preparation in the furnace comprises the steps of: feeding the pretreatment pellets into a yellow phosphorus electric furnace, and performing second high temperature roasting cementing by furnace gas; reacting in a melting zone to prepare the yellow phosphorus. The method can effectively use powdery phosphorite, obviously improve finished product quality and obviously reduce energy consumption.

Description

technical field [0001] The invention relates to the preparation of phosphorus, in particular to the technical field of preparation of yellow phosphorus. Background technique [0002] Yellow phosphorus is an important chemical raw material, mainly used in the preparation of thermal acid and phosphate, widely used in fertilizers, food, medicine, pesticides, electronics and other fields. [0003] The preparation of yellow phosphorus includes direct refining of high-grade lump ore or refining of low-grade phosphate ore. As time goes by, the grade of phosphate ore available for direct use will gradually decrease. The cost of production will increase day by day, so it is an inevitable trend to change the way of refining lump ore. [0004] In the preparation method of yellow phosphorus, the most commonly used method is the electric furnace method, which mainly mixes phosphate rock, coke, and silica in proportion and then adds it to the electric furnace. 2 o 5 Yellow phosphorus i...

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Problems solved by technology

[0005] The pretreatment methods of phosphate rock include sintering method, pelletizing method, nodulation method, briquetting / tabletting method, etc. my country has introduced rhubarb phosphorus calcination technology, and its calcination temperature is 400~500°C, the calcination time is long, and the heat consumption is high , and is not friendly to the environment; for fine ore, the pelletizing method is a better method, but in the process of pelletizing fine ore, it is necessary to spread carbon powder on the fine ore first, and then carry out high-temperature sintering Agglomeration, the sintering temperature required is generally higher, the sintering time is longer, and the energy consumption is high. The reduction reaction at high temperature will easily lead to the loss of phosphorus resources with the gas.

[0006] In the prior art, part of the binder needs to be added during the pelletizing process to enhance the enrichment capacity. Currently, clay, water glass, sodium humate, etc. are mostly used as binders, all of which have side effects on the subsequent production of phosphorus in an electric furnace: Using clay as a binder will reduce the grade of phosphate rock and increase the amount of slag. If the P in the raw ore 2 o 5 The mass fraction is 25%, and after adding 5-8% clay to make balls, P in dry balls 2 o 5 The mass fraction drops to 23%, and the mass increases by 1.3 to 1.5 times. The clay in the sintered ball is finally discharged in the form of slag, so the quality of the slag will usually increase by 1.5 to 2.0 times, resulting in a decline in economic benefits; at the same time, the clay (slag) is discharged. It will bring out a lot of heat energy and cause huge heat loss; water glass (sodium silicate) is used as the adhesive, although it is an efficient water-soluble adhesive, it has good bonding performance, the hardness of the pellets is large and the surface of the pellets is gloss, but the obtained pellets will carry part of the sodium silicate along with the furnace gas to the refining system during the electric furnace refining, and the sodium silicate will react with the fluorine in the refining system to form oily sodium fluorosilicate, which seriously affects the The normal operation of the refining system brings new pollution to the circulating water system at the same time; sodium humate is used as an adhesive, and sodium humate is a commonly used adhesive with good adhesion, but it is an organic matter. The complete thermal decomposition temperature is about 550°C. When phosphate rock pellets are refined in an electric furnace, they are in the raw material layer at this temperature. If a large amount of binder decomposes at this time, the pellets will burst and affect normal production.