Need Quality Reduced Iron Powder Production Controls Which Processes?
Need quality reduced iron powder production controls which processes?
At present, reduced iron powder, magnetic materials industry mainly depends on scale and super pure iron concentrate powder, due to the scale components, complex chemical composition, and supply is limited, it is difficult to meet the needs of high grade iron powder products. Super pure iron concentrate powder for large production scale, composition is not chaos, few harmful impurities, many developed countries are as a raw material in the production of reduced iron powder products, and magnetic materials. With the development of China's high-tech industry, and also increasing demand for high-grade iron powder. According to powder metallurgy industry statistics in 2012, needs about 30~50 million t of reduced iron powder, and years of iron powder production is far from enough to meet the demand, the market potential is huge. Meanwhile, for some iron ore business is also a rare market opportunity. Production technology of super pure iron concentrate powder for iron powder, magnetic material industry technology innovation to provide high quality materials guarantee. Key process control in quality reduced iron powder production focused on the following:
1, during a restore, skip restoring the finish process system should be used to make sponge iron does not appear cooked, or severe burns, cementite (Fe ≥ 98%,C=0.20~0.30%). Rolling iron oxide as raw materials, powder coke as reducing agent, reducing temperature 1100~1150℃ is appropriate.
2, sponge iron process, quality should be paid attention to in the control of crushing, screening will be on separate collection in each stage through product, to keep a variety of bulk specific gravity, sieve analysis and particle shape, should be dealt with separately later in the process, to ensure that the many varieties of iron powder has its own advantages.
3, secondary reduction process optimal process conditions should be based on a reduction of iron oxide, carbon to determine. As your reduced iron powder but not serious when overburning (Fe ≥ 98%,C=0.02~0.03%), better secondary reduction technology to select a temperature of 900 degrees Celsius, about time 60min suitable. Iron powder is generally had lower H2 loss and carbon and sulfur content, with high compression performance.
4, due to decomposition of ammonia in secondary reduction value, oil removal measures to be used to prevent residual oils with liquid ammonia in ammonia decomposition of carbon effect affecting the atmosphere. The decomposition temperature of 950 degrees Celsius should be used and good nickel catalyst, ensure good effect. On the decomposition of gas molecular sieve purification should be used in order to reduce the amount of residual ammonia to prevent micro-nitride and effect of attenuation caused by residual ammonia. In the end when intake reduction furnace II, protection of the atmosphere should be lower than the dew point-11.5 degrees centigrade in order to avoid the oxidation of iron powder.