Method for producing ferrochromium alloy by two-step smelting reduction of chromite powder

Abstract

The invention discloses a method for producing a ferrochromium alloy by two-step-process smelting reduction of ferrochromium mineral powder. The method comprises the following steps: (1) preparing raw materials, namely uniformly mixing the ferrochromium mineral powder with coke powder, and pelletizing on a disk pelletizing machine; (2) performing pre-reduction, namely uniformly distributing green pellets on a chain grate, preheating and drying the green pellets, loading the green pellets which are preheated and dried into the rotary kiln for pre-reduction, and burning by using coal gas generated by a final reduction section iron bath furnace for heat supply, wherein an adopted heat source is kiln tail waste gas from a rotary kiln; (3) performing final reduction, namely adding high-temperature pre-reduction pellets from the top of the iron bath furnace through a spiral discharger, thermally loading the pellets into the iron bath furnace for melt separation, spraying coal powder and oxygen into an iron bath by utilizing a coal oxygen spraying gun, burning the coal powder and the oxygen in the iron bath, supplying heat needed by the melt separation, after the melt separation is completed, performing slag iron separation, and discharging iron and slag. According to the method, the ferrochromium mineral powder can be largely treated, and utilization of powder mines is improved, so that the production cost of the ferrochromium alloy is reduced, and large-scale production is facilitated.

Description

technical field [0001] The invention relates to an alloy production method, in particular to a method for producing ferrochrome alloy by using a two-step smelting reduction method of chromite powder, which belongs to the field of non-blast furnace ironmaking. Background technique [0002] Ferrochrome alloy is an essential raw material for the production of stainless steel. A large amount of ferrochrome alloy is used in the production of stainless steel. Therefore, the ferrochrome industry has a great influence on the stainless steel industry. Electric furnace is currently the main production equipment of ferrochromium alloy, and smelting needs to consume a lot of electric energy and coke. my country's chrome ore resources are poor, and most of the chromite ore has to rely on imports. At present, fine ore accounts for about 80% of the chromium ore mined every year in the world. The fine ore grade is high and the price is relatively low, but too much fine ore during the smel...

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Problems solved by technology

However, the rotary hearth furnace has the following disadvantages and technical difficulties: the hot air flow does not pass through the material layer, mainly relying on radiation heat transfer, and the thermal efficiency is low; the material layer is only 2 to 3 balls thick, and to achieve a certain production capacity, the equipment occupies an area It must be large, so the production capacity and equipment size are difficult to match with the iron bath final reduction reactor

This method uses an electric furnace as the final reduction reactor for smelting ferrochrome alloys, which consumes a lot of power and is not suitable for promotion in areas with tight power or high costs.

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