GB1415430A - Method of manufacturing pellets from iron-containing particulate material - Google Patents

Abstract

1415430 Pelletizing siderurgical waste SOC D'EXPLOITATION DES SOUS PRODUITS SIDERURGIQUES SOPS ID and SOC LORRAINE DE LAMINAGE CONTINU 12 Dec 1973 [12 Dec 1972 2 Oct 1973] 57548/73 Heading B5A Iron-containing particulate material is pelletized with a binder, the mixture before pelletizing comprising by wt.: up to 7% water, up to 6% binder, up to 25% dry fines of particle size less than 100 Á and the remainder being fines of particle size at least 100 Á. As shown in Fig. 2, waste products are fed from heaps 1 to hopper 2 and to magnetic screen 3. Non-magnetic waste is fed to collector 4 and heaps 5 for removal. Magnetic waste of particle size at least 10 mm. are recycled via crusher 6 and circuit 7 to screen 3, the magnetic product of size < 10 mm. is fed via mixer 8, oven 9, metering unit 10 to mixer 11 which has three additional inputs: a liquid bituminous binder from tank 13 via heating trough 12, siderurgical decantation sludge from reservoir 14 fed by a sludge tank 15 and dry dust from reservoir 21. The outlet of mixer 11 feeds a cell press 16, e.g. having two moulding wheels to produce pellets which are transported on cooling grating 17 to a stock pile 20, fines or residues being collected at 18 and recycled to mixer 8. Sensors 22-24 sense the humidity, temperature and mass flow rate respectively at the outlet of mixer 11. Sensor 22 is connected to controller 25 to regulate the flow rates of sludge and dust and keeps the ratio therebetween constant by control means 30, 31. Sensor 23 is connected to flow controller 27 acting on means 28 which regulates the fuel fed to the burner of oven 9. Sensor 24 regulates the binder flow rate by flow rate controller 26 and control means 32. The product pellets typically contain 66-68% iron and small amounts of phosphorus, sulphur, silica, lime and water and may be used in blast furnaces, steel works etc.