In August 2022, this Mongolian customer saw our independent website and asked us about ferrochromium. Our business manager Tina carefully shared our ferrochrome product details, company qualifications, and other information with customers. Customers have great trust in zxferroalloy and have been maintaining close communication with business manager Tina. The customer’s factory visit plan was postponed until after the Spring Festival due to the epidemic. The customer required Medium Carbon Ferro Manganese.
Medium Carbon Ferro Manganese Specification the Customer Required
|Grade||Mn||C max||Si max||S max||P max|
|Size: 30-70 mm|
The company strictly controls the product quality of medium-carbon ferromanganese. Chemical content detection of raw materials before production, detection of manganese content and residue content during production, chemical content detection, and particle size processing of products before leaving the factory. SGS quality inspection.
The raw materials for the production of low carbon ferromanganese by electrosilicothermal process are manganese ore, manganese silicon alloy and lime.
The requirements for manganese ore are: Mn> 40%, Mn/Fe> 7, P<0.1%, SiO2<15% manganese-rich oxide ore, smelting medium and low carbon ferromanganese should not be used sinter and manganese-rich slag, manganese ore particle size is not greater than 50mm, moisture should be less than 6%.
The requirements for manganese silicon alloy are: the carbon content should be determined according to the carbon content of medium and low-carbon ferromanganese in the chain, and the higher the manganese content, the better. The usual manganese content is 67%-69%. When cold loading is adopted, the particle size of the manganese silicon alloy is less than 30mm, and the high carbon layer is removed. The liquid silicomanganese alloy blending method is used to remove the slag during hot blending.
The requirements for lime are :CaO> 85%, P≤0.02%, SiO2≤3%, particle size 8-40mm, no carbonaceous inclusions, should not be used powder, unburned lime.
Medium Carbon Ferro Manganese Production & Delivery
Cold loading is a traditional method to produce low carbon ferromanganese. The refining furnace used is the tilting graphite electrode arc furnace. The smelting process of middle and low carbon ferromanganese includes recharging, arc starting, charging, melting, refining, and iron draw.
Furnace filling: furnace lining is made of magnesium material: The furnace lining is eroded by slag and metal and arc high temperature at the high temperature of smelting, furnace bottom and furnace refractory materials gradually thin, iron outlet are more easily damaged, after the completion of iron on the furnace, it is necessary to plug out the iron and repair the furnace immediately.
Arc starting, charging and melting: After the completion of the furnace, first lay a layer of lime extracted from the batch at the bottom of the furnace, then add some manganese silicon alloy arc, and then add the rest of the mixture into the furnace at one time. After the charge is added, electricity is fed to the full load. In order to reduce heat loss and shorten the melting period, the charge at the edge of the furnace should be pushed near the electrode and the core in time, but the slag should be prevented from turning over and spraying: after the basic melting of the charge (at this time the alloy silicon content has been reduced to 3%-6%, the slag basicity and manganese content are close to the final slag), the refining period will be entered.
Refining: Since the slag temperature at the end of melting has reached 1500-1600 ° C, the desilication reaction has basically ended, so the desilication rate during the refining period is slowed down. In order to accelerate desiliconization and shorten the refining time, the molten pool should be stirred several times, and periodic sampling to determine the silicon content of the alloy and determine the iron time. The silicon content of the alloy is generally controlled in the range of 1.5%-2.0%. After refining for a period of time, the silicon content of the alloy is still high, and some manganese ore and lime can be added to the furnace, and it can be refined until the silicon content is qualified before it can be baked: extending the refining time can reduce the manganese content in the slag, but it will lead to the evaporation loss of manganese and the increase of electric energy consumption. Therefore, it is not appropriate to overemphasize the manganese content in slag.
Iron: When the silicon content of the alloy basically meets the requirements, the power can be cut off for sedation, so that the metal particles in the slag fully settle, and then the iron is produced. When the iron is drawn, the alloy and the slag flow into the hot metal ladle together. Due to the mixed impact between the slag and the alloy during the iron drawing, 0.2%-1.0% of the silicon can be removed outside the furnace. Fresh hot metal temperature is high, and mixed with slag, not immediately pouring, to prevent burning ingot mold and resulting in slag inclusion in the iron, should be calm and cooling for a certain time after pouring, the use of covering slag insulation pouring. The depth of the casting mold should not exceed 300mm, otherwise the central part of the alloy will be cooled too slowly, resulting in segregation, impurity enrichment, and product scrap in serious cases.