High-quality production methods, there are 5 kinds, one is the use of selected furnace to produce high-purity , the second is the use of external blowing chlorine refining method to produce high-purity and low-carbon , the third is the use of furnace external blowing oxygen method to produce high-purity and low-aluminum ferrosilicon Five is the use of selected furnace method to produce low-aluminum, low-carbon ferrosilicon.
The production of high purity by using selected furnace material is mainly through the selection of quartz stone and petroleum coke, wood block, charcoal and silicon steel sheet raw materials for smelting production, in order to reduce the content of impurity elements in the product. Because of the large fluctuation of raw material quality, the smelting production process inevitably brings some impurities, so the reduction rate of impurity content in the product is limited, the product quality is not high, the yield is low, and the production furnace condition is difficult to maintain, the furnace mouth operation is more difficult, the product production cost and energy consumption is larger, the economic index is poor.
Furnace method to remove calcium, aluminum effect is better, but the exhaust gas is more, and the production often produces leakage and the release of chlorine graphite pipe break and stop refining and so on, which seriously pollute the environment, endanger the health of workers, and the production equipment corrosion is greater. The method of blowing oxygen outside the furnace is refined outside the furnace, and the removal of impurity calcium, aluminum and carbon elements in the product is also better. However, in the use of the process, due to the heavy iron tumble, splash loss is large, the temperature of molten iron drops rapidly, resulting in large loss of sticky packets, iron, the statistical loss of data in 12%-20%. The graphite tube for blowing oxygen also often breaks the accident and stops refining, the finished product rate is low, and the economy is also very uneconomical.
Selection of furnace methods for the production of low-aluminum, low-carbon is mainly through a selection of reducing agents, such as blue carbon, gas coke and other raw materials for smelting production, in order to reduce the impurity elements in the product, mainly aluminum content of the purpose. Because of the large fluctuation of raw material composition, the smelting process inevitably brings some impurities, so the reduction rate of impurity content in the product is limited, the aluminum content can generally be reduced to 1.6%, the maximum can only be reduced to 1.2%, the carbon content of 0.2%, can only produce some brands of products.