Effect Of K, Na, F On The Reduction Kinetics For Bayan Obo Iron Ore

Bayan Obo Multi-metal resources are rare in the world which contain71kinds ofelements, including iron, niobium, rare earths, thorium, potassium, sodium, fluorine and soon. The current traditional blast furnace process for Bayan Obo iron ore requires newmethods and new technologies, and basic researches on the carbon reduction of Bayan Oboiron ore is thus highly anticipated.This thesis mainly research carbon reduction process of Bayan Obo iron ore bythermogravimetric(TG) mass spectrometry(MS). The related kinetics was caculated andthe speed limitation was analyzed. Since the composition of Bayan Obo iron ore iscomplicated, on the basis of the works previouly reported, we probed the effects of thecomposition of Bayan Obo iron ore on its carbon reduction process by studying the effectsof K,Na,F on the reduction of synthesized ore. in the experiments, K2CO3and Na2CO3instead of K2O and Na2O were used.The experimental results proved that the carbon reduction process of Bayan Obo ironore is divided into three stages. The reaction with carbon begins at384℃and ends at1318℃. During the reduction process, only CO and CO2are escaped, and the highercarbon content corresponds to higher degree of reduction and the higher rate ofmetallization. According to the Arrhenius equation, the activation energy of carbongasification reaction and gas phase diffusion is96.8and76.5kJ/mol, respectively.Therefore, under the conditions in this study, the carbon reduction is co-controlled bycarbon gasification reaction and gas phase diffusion. The addition of K2CO3, Na2CO3andCaF2decreases the reduction temperature and time, The reaction activation energy and theabsorbed heatby the reduction reaction are also reduced due to the addition of differentcontents of K2CO3, Na2CO3and CaF2.