EA030670B1 - Method for producing briquettes for ferrochrome production - Google Patents

Abstract

The invention is related to metallurgy, in particular, to preparation of charging materials for production of ferro-alloys. The technical result consisting in simplification of the method, reduction of energy consumption and provision of utilization of fine fractions of ore raw stock is attained by provision of a method for producing briquettes for ferrochrome production comprising preparing, by mixing, small-grained chrome-containing raw material, a carbonaceous reducing agent and a binder, pressing to form briquettes and drying of briquettes, wherein, in accordance with the invention, chromium ore of grain size lower than 5 mm is used as a chromium-containing raw material, and power-generating coal of grain size lower than 5 mm is used as the carbonaceous reducing agent, with the following proportion of the components, wt.%: chromium ore of grain size lower than 5 mm - 65-75; power-generating coal of grain size lower than 5 mm: - 20-25; binder - the balance. Pressing briquettes is performed at a pressure of at least 5 MPa, and drying is carried out at a temperature of 20-40°C.

Description

The invention relates to metallurgy, in particular to the preparation of charge materials for the production of ferroalloys. The technical result is a simplification of the method, reduction of energy costs and ensuring the utilization of small fractions of ore raw materials is achieved by the fact that in accordance with the invention, Chrome ore with a fraction of less than 5 mm is used as a chromium-containing raw material, and coal with less than 5 coal is used as a carbonaceous reducing agent. mm, in the following ratio, wt.%: chrome ore fraction less than 5 mm - 65-75; coal energy fraction less than 5 mm - 20-25; binder rest. Pressing briquettes is carried out at a pressure of at least 5 MPa, and drying is carried out at a temperature of 20-40 ° C.

030670

The invention relates to metallurgy, in particular to the preparation of charge materials for the production of ferroalloys.

A method of obtaining chrome briquettes for the production of ferrochrome, including mixing chrome-containing dust trapped in the gas cleaning system in the smelting of ferrochrome, with a binder, briquetting and subsequent drying of briquettes. Dust directly from the gas cleaning system is reloaded into metal containers, in which it is kept for a period of time before feeding for mixing, which reduces the volume by 10-20%, while water is used as a binder in an amount of 5-10% of the mass of dust, and drying the obtained briquettes are carried out in natural conditions by their aeration (RF patent No. 2083693, cl. SW 1/24, 1997).

This method does not allow to recycle waste in the form of ore dust sent to the sludge dump.

A known method of manufacturing briquettes for the production of chromium ferroalloys, including the preparation by wetting, thorough mixing of fine fraction and powdered chromium-containing raw materials, carbonaceous reducing agent and complex inorganic binder, pressing the mixture, briquetting and drying briquettes. As a complex inorganic binder using liquid glass in the amount of 8-12 wt.% Of the charge and the concentrate of aluminum slag in the amount of 55-60 wt.% Carbonaceous reducing agent, and drying is carried out in two stages in the temperature range of 80-350 ° C in an atmosphere containing CO ₂ . The main components of the mixture are melkofraktsionny chromite raw materials (fraction <3 mm), dust and sludge from gas cleaning and aspiration installations in the production of ferroalloys, carbonaceous reducing agent - coke fines fraction <3 mm and the concentrate of aluminum slag in a ratio, wt.%: Chromite ore raw materials - 75-80, carbonaceous reducing agent - 15-17, concentrate aluminum slag - 4-9, mix thoroughly with the addition of moisture 2.5% by weight of the mixture. After obtaining a homogeneous charge mixture, 8-12 wt.% Of liquid glass with a density of 1.4-1.45 g / cm are added to it. Pressing the prepared mixture is carried out with roller presses at a pressure of 25-35 MPa, drying is carried out first at a temperature of 80-90 ° C, and then at 280350 ° C, the drying time is 65-90 minutes (RF Patent No. 2000345, class С22В 1/243, 1993).

The disadvantage of this method are significant energy consumption in the implementation of the drying, as well as the need for drying in two stages, which complicates the method. In addition, this technology does not allow to dispose of small fractions of ore raw materials and involves the use of expensive carbonaceous reducing agent in the form of coke.

The objective of the invention is to develop a method of producing briquettes for the production of ferrochrome from industrial waste in the form of small fractions of ore raw materials and small fractions of coal, which are not used in normal production and sent to the sludge disposal site.

The technical result is a simplification of the method, reduction of energy costs and ensuring the utilization of small fractions of ore raw materials is achieved by the fact that in accordance with the invention, Chrome ore with a fraction of less than 5 mm is used as a chromium-containing raw material, and coal with less than 5 coal is used as a carbonaceous reducing agent. mm in the following ratio, wt.%: chrome ore fraction less than 5 mm - 65-75; coal energy fraction less than 5 mm; 2025; binder - the rest; pressing briquettes carried out at a pressure of not less than 5 MPa, and drying is carried out at a temperature of 20-40 ° C.

Implement the method as follows.

Example 1. To obtain briquettes use the following equipment: a roller press, mixers, a hopper for receiving raw materials with a metering device, conveyor belts.

The raw materials are chrome ore less than 5 mm and coal energy fraction less than 5 mm. As a binder, liquid glass or another component can be used.

The raw materials are fed into the bunker, from the bunker it goes to the conveyor belts, after which, through a sieve, strictly in a certain amount, according to the recipe, the conveyors are fed into the mixers. Then a binder is fed into the mixers and the components are mixed, and water is added if necessary. Then the mixture of conveyor belts delivered to the receiving hopper press, where from the hopper in equal portions served on the pressing at a pressure of 5 MPa. The press leaves the finished product in the form of briquettes, which pass the necessary drying at a temperature of 40 ° C for 3 days. Next, the finished product is sent to the metallurgical furnaces, which produce high carbon ferrochrome.

Components taken in the following ratio, wt.%: Chrome ore fraction less than 5 mm - 65; coal energy fraction less than 5 mm - 25; liquid glass - 10.

Example 2. The method is carried out according to example 1, but the components are taken with the following ratio, wt.%: Chrome ore - 73; energy coal - 20; liquid glass - 7.

Pressing is carried out at a pressure of 25 MPa, drying the briquettes at a temperature of 20 ° C for 7 days.

The main advantages of the proposed method are as follows:

- 1 030670

utilization of small fractions of ore raw materials that are not used in furnaces separately; the use of a fine fraction of coal, replacing them with expensive imported coke. This technology allows the use of waste in the form of dust, which are not used in normal production and go to the sludge disposal site.

Claims (1)

CLAIM The method of producing briquettes for the production of ferrochrome, including preparation by mixing small-fraction chromiferous raw materials, carbonaceous reducing agent and binder, pressing briquettes and drying them, characterized in that chromium ore fraction less than 5 mm is used as chromium-containing raw material fractions less than 5 mm, in the following ratio of components, wt.%: chrome ore fraction less than 5 mm - 65-75; coal energy fraction less than 5 mm - 20-25; binder - the rest; pressing briquettes carried out at a pressure of not less than 5 MPa, and drying is carried out at a temperature of 20-40 ° C.