Recovery Of Titanium And Iron From Vanadium Bearing Titanomagnetite Based On Direct Reduction Technology

Vanadium bearing titanomagnetite ore is quit rich in Panxi zone of China and its explored reserve is up to 98.49 billion tons, which accounts for 95%of total vanadium bearing titanomagnetite resource in China. Therefore, how to realize the high efficiency utilization of vanadium bearing titanomagnetite resource is important for promoting the development of our national economy.Vanadium titanium magnetite from Pansteel as raw material and coal as reduction agent are used to make pellets in the study. Then the method of direct reduction is used to reduce the raw pellets to metallized pellets. After that iron and slag are separated in the high temperature smelting separation progress. With the theoretics methods of thermodynamics and kinetics, modern microscopic test technology of X-ray diffraction, optical microscopy, scanning electron microscopy and etc, modern means of monitoring like ICP, XRF, the study of direct reduction and high temperature smelting separation of vanadium bearing titanomagnetite is undertaken. The conclusion is as follows:(1) The thermodynamic study of vanadium bearing titanomagnetite reduction reaction indicates, in the temperature range of 1300 K-1600 K, oxides of iron can be reduced by fixed carbon while those of titanium can't, and the CO can't reduce them. So the separation of iron and titanium is possible by controlling the reduction reaction in the temperature range.(2) Vanadium bearing titanomagnetite pellets containing carbon dynamics model in the process of direct reduction is discussed preparatory. The restrictive link in the process of reduction and The activation energy of the reaction is determined through the calculation.(3) The effect of C/O, reduction temperature and reaction time on metallized rate of pellets is investigated in the direct reduction experiments and the direct reduction experiments in which C/O is decreased is undertaken. The conclusion is as follows: ? In the same condition of temperature and time, the high metallized rate of pellets can be achieved easily while the C/O of pellets is high; ? In the same condition of time, increasing temperature is better for the increase of metallized rate of pellets; ? In the initial stage of the reaction, the metallized rate of pellets will increase with the prolongation of time, and after that it differs with the difference of reaction atmosphere and C/O.(4) Reaction atmosphere, melting temperature, constant temperature time and the effects of carburizing on the melting is investigated in the high temperature smelting separation experiment. The conclusion is as follows: ? under the protection of nitrogen, iron crystal grew up gradually with the melting temperature increasing in the exploration stage; ? under the condition of reducing atmosphere and carburizing in full, separation of slag and iron can be realized; ? By using scanning electron microscopy and analysising the elements distribution of melting samples, it is can be known that metallic iron phase is the main phase in the metal sample and titanium oxide and compound oxides of Si, Al, Mg is the main phase in the slag sample; ? under the condition of reducing atmosphere and limited carburizing, separation of slag and iron can be realized by improving slag composition and proper prolonging melting time.