Smelting process for high carbon ferro-chrome through sealed open arc electric furnace

Abstract

The invention discloses a smelting process for high carbon ferro-chrome through a sealed open arc electric furnace. The smelting process for the high carbon ferro-chrome through the sealed open arc electric furnace comprises the following steps of compounding and mixing 400 to 600 parts of chrome ore, 40 to 50 parts of bentonite and 60 to 80 parts of magnesium-containing accessory ingredient; thenconveying into a rotary kiln through a belt; utilizing the burning heat of the magnesium-containing accessory ingredient for drying and / or preheating the raw materials; and sintering powdery chrome ore into massive chrome ore required for an electric furnace through a cementing action of the bentonite. Mixing and compounding are carried out through a compounding center, the materials are added into the sealed open arc electric furnace through a furnace top bin, the chrome ore is utilized as the raw material, coke powder or pulverized coal is adopted as a reducing agent for smelting the high carbon ferro-chrome, the powdery chrome ore and the powdery reducing agent are used by 100 percent for the new process, and the coke powder or the pulverized coal is used as the reducing agent replacing an old process using lump coke for producing, so that the aims of saving resources and reducing the production cost are achieved; and the smelting process for the high carbon ferro-chrome through the sealed open arc electric furnace provided by the invention comprises a sealed direct-current electric furnace technology, equipment is simple, the safety in operation is realized, and the convenience in maintenance is realized.

Description

[0001] Technical field: [0002] The invention relates to the technical field of ferroalloy smelting technology and ferroalloy production equipment, and more specifically relates to a smelting technology of high-carbon ferrochrome in a closed open-arc electric furnace. [0003] Background technique: [0004] High-carbon ferrochromium is used as an alloying agent in steelmaking; steel with a chromium content of about 0.5% will significantly improve toughness and hardness; steel with a chromium content of 2% to 6% has good wear resistance and corrosion resistance Steel with a chromium content of more than 12% has the advantage of high temperature strength; stainless steel is the most common type of steel with a high chromium content; the ferrochrome consumed in the production of stainless steel accounts for more than 80% of the chromium-based ferroalloys, and the high-carbon ferrochrome The raw material is chromite; an important feature of chrome ore resources is that lump ore re...

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Problems solved by technology

[0004] High-carbon ferrochromium is used as an alloying agent in steelmaking; steel with a chromium content of about 0.5% will significantly improve toughness and hardness; steel with a chromium content of 2% to 6% has good wear resistance and corrosion resistance Steel with a chromium content of more than 12% has the advantage of high temperature strength; stainless steel is the most common type of steel with a high chromium content; the ferrochrome consumed in the production of stainless steel accounts for more than 80% of the chromium-based ferroalloys, and the high-carbon ferrochrome The raw material is chromite; an important feature of chrome ore resources is that lump ore resources are becoming less and less; there are not many chrome ore reserves with a chromium content greater than 42% in nature; currently the mainstream of the chrome ore market is concentrate and friable ore; Lump chromium ore is close to depletion, and the most important equipment for ferroalloy smelting is submerged arc electric furnace; submerged arc electric furnace produces high-carbon ferrochrome mainly using artificially agglomerated powder such as massive chromium ore, pellet ore, sinter or cold-pressed ball. Chromium ore, powder chromium ore pelletizing, agglomeration, and sintering are indispensable processes for ferrochromium production today; if the proportion of fine ore in the furnace ore is too high, the power consumption of smelting will increase, the recovery rate of chromium will decrease, and the occurrence of smelting will occur. Severe equipment and personnel casualties occurred due to collapse accidents; the proportion of powder ore in the ore into the furnace generally cannot exceed 15%; for this reason, the production of high-carbon ferrochrome requires pretreatment and sintering of chromium ore into balls or blocks; the production process is long, High energy consumption and high cost. At present, most ferroalloy smelting uses cold ore directly into the furnace for smelting; although the technology of preheating ore can significantly reduce power consumption, the technology of ore preheating and hot charging is difficult, the process is long, and the investment in equipment is large. Bottom anode conduction and cooling are the key technologies for smelting DC electric furnaces; currently used technologies mainly include: conductive furnace bottom type, contact pin type, ring steel sheet type, etc. The development of DC electric furnace smelting is a restrictive link. The temperature of flue gas in open arc smelting is extremely high, and it is very difficult to recover gas by dry method. Foreign DC electric furnaces all use wet gas dust removal. The equipment is complex and expensive, consumes a lot of water resources, and easily causes water pollution. , the high voltage of the furnace shell will bring safety hazards

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