Titanium And Ferroalloy Were Prepared By Molten Salt Electrolysis Of Waste Slag Containing Titanium

Titanium containing waste slag is the smoke and dust generated in the Kroll process of TiCl₄ production,which is directly returned to the smelting furnace.Due to the relatively small particle size,the furnace will be clogged with the addition amount of more than 15%,resulting in a low utilization rate.Due to the large storage,the environment is polluted and resource are wasted.The electrolysis method of molten salt is a simple and green material preparation method.In view of the slow electrode-oxidation rate of molten salt and the controversial mechanism of ferrotitanium alloying,this paper takes the titanium-containing waste residue as the raw material,on the basis of the electrolysis of molten salt to prepare titanium metal,and prepares ferrotitanium alloy by doping Fe₂O₃.The influences of cathodic micro-structure and electrolysis parameters on electrode-oxidation were mainly studied,and the titanium-ferro alloying mechanism and impurity behavior of titanium concentrate were compared.The main conclusions are as follows.The preparation conditions of the cathode have an important effect on its micro-structure.When the average particle size is 4.55?m,the forming pressure is 4MPa,and the sintering temperature is 1050?,the porosity of the cathode plate is 41.21%,the electrochemical activity is good,the electrolytic product is obviously spongy,and the content of titanium reaches 98.32%.When Fe₂O₃ is doped with Ti/Fe atomic ratio of 1.2:1,the porosity of the cathode plate is 39.96%at forming pressure of 2MPa and sintering temperature of 950?.The cathode plate has good electrochemical activity,and only Fe Tiphase is detected in the product.Electrolytic temperature,cell voltage,electrolytic time and doping amount of Fe₂O₃have obvious effects on the product.Increasing electrolytic temperature is conducive to the electrode-oxidation reaction.When the temperature is higher than 1050?,the cathode will undergo sintering,resulting in densification of the structure and restricting the migration of ions inside the cathode.The increase of cell voltage and electrolytic time is beneficial to increase product purity.With the increasing of doping amount of Fe₂O₃,the content of impurity elements decreases,but the structure is loose.Ti/Fe atomic ratio is 1.2:1,900?electrolysis temperature,3.1V cell voltage is more suitable,electrolysis 9h product is spongy,the phase is mainly Fe Ti,no impurity element detected.Electrolysis process of titaniferous waste slag and titanium concentrate:the first stage is the generation of intermediate products CaTiO₃,Fe and reducing agent Ca.The second stage is the titanium-ferroalloy process.The main alloying mechanism of the titanium-containing waste residue is as follows:CaTiO₃ and TiO₂ are deoxidized step by step to form the low price oxide of titanium and the metal titanium,which is combined with Fe to form the titanium-ferroalloy.In the early stage of electrolysis,part of CaTiO₃ reacts with the surrounding enrichment Fe to form ferrotitanium alloy in one step due to the uniform distribution of Ti-Fe element in the titanium concentrate.At the later stage of electrolysis,the low oxide of titanium and the metal titanium and Fe are combined to form ferrotitanium alloy.The impurity behavior of titanium-containing waste slag and titanium-iron concentrate prepared by electrolysis is similar:most impurity elements are reduced to elemental substance and migrated to Ca Cl₂ molten salt;a small part of the residue in the cathode can be removed by pickling.At the same time,part of the impurities will form the corresponding chloride volatilization.