Improvement in segregation of sinter-mix through incorporation of magnetic charging chute at Sinter Plants

摘要

In conventional sintering process of uniform solid fuel distribution with sloping chute for charging the materials,heat deficiency at top layer and low permeability are commonly observed process deficiencies.These process shortfalls affect the quality,cost and productivity of sinter making.These process deficiencies are effectively tackled by incorporation of a “magnetic charging chute” in place of the conventional “sloping chute” in sinter machines.Magnetic field induced on charge materials by a permanent magnet provided in the charging chute,improves size segregation of charge materials by charging the coarser particles to the far side of the charging chute and finer particles to near the charging chute,into the continuously forward moving pallets.This improved segregation of charge materials effects in formation of highly permeable sinter-bed in the pallet facilitates improved permeability of the sinter bed.The magnetic field on the charge materials also helps in efficient segregation of magnetic ferrous metals consists mill scales and returns sinter fines,which are heat generative and low temperature melting capabilities,provide additional heat at the top for efficient sintering operation through improvement in yield at top layer of sinter bed.Laboratory trials with sinter raw materials were conducted by simulating the charging conditions in proportional scale to estimate the optimal magnetic field requirement in the magnetic chute applications.Mathematical equations were used to validate the magnetic strength,estimated through laboratory tests.On the basis of the laboratory tests,‘magnetic segregation chute’ has been designed,developed and successfully installed at commercial scale in one of the sinter machines of Durgapur Steel Plant and Bokaro Steel Plant.The industrial trials have witnessed various technological benefits such as increase in average air-filtration velocity,strength of sinter,machine speed,productivity and reduction in solid-fuel consumption and return-sinter fines.