The Research And Development Of The Techniques For Siderite Powder Roasted And Magnetized In The State Of Fluidization

For the problems of existing siderite process as low efficiency and high energy consumption, the technique of fluidization was introduced into the magnetized roasting of siderite.Siderite is a kind of iron ore widely existing in nature while less than 10 per cent has been exploited. As the easy-to-concentrate iron ore resource is gradually exhausted nowadays, the new industrial beneficiation technologies of roasting and magnetic separation should be introduced into siderite processing.This research is aiming at developing a new technology and techniques for siderite as "dry grinding - fluidizing magnetized roasting - low-intensity magnetic separation" with the siderite in Daxigou, Zhashui county, Shaanxi province. The deposit of the ore body amounts to about 3.02 hundred million tons and the main ferric component is siderite. The grinding property and the thermal kinetics research were conducted. The process of siderite magnetized roasting was investigated both in piled state and in the state of fluidization. The essential parameters resulted are suggested for the technics of suspending roasting. The influences of cooling mode and the intensity of magnetic separation on the result of beneficiation were also discussed. The conclusion could be drawn as follow:1. Siderite is a kind of easy grinding material with the grinding work requirement being 5.95kW·h/t. It is expected that roller mill could be used for the grinding of siderite.2. The kinetic study of thermal decomposition shows that siderite is a kind of material which decomposes easily. The temperature of the decomposition ranges from 410℃ to 610℃ and the activation energy is 355.95kJ mol^-1.3. The iron grade and iron recovery of concentrate obtained from roasted ore by roasting for 15minutes under 750℃ in piled state reaches 59.12% and 89.87% separately.4. The siderite powder in the state of fluidization can be roasted and magnetizedefficiently and rapidly. The concentrate of roasted ore obtained by 3min roasting under 700°C results in favorable indexes, with iron grade being 57.20% and iron recovery being 94.36%.5. Water quenching is the best way to cool the roasted ore. On the other hand, the oxidation of the products could also be prevented by cooling rapidly in the air. This suggests that it is feasible to cool the roasted ore by air stream in suspension state. In summary, a rapid magnetized roasting of siderite was achieved via adapting the technology of roasting in fluidization and the essential parameters are offered for reference to the establishment of a new approach scheme of suspending roasting. It is expected that this will promote the industrial utilization of siderite greatly.