Steam Hydrolysis Titanium Tetrachloride Dust Collection Slag Process

In the process of producing titanium tetrachloride by boiling chlorination,a large number of dust collecting slag will be produced.These dust collecting slag will deliquescence in the air,and then produce acid mist.When it meets with water,it will form strong acid aqueous solution,which will cause serious pollution to the environment.At present,there is potential pollution in the treatment of dust collecting slag,which can not fundamentally solve the problem.In this paper,the method of steam hydrolysis of chlorinated dust collection slag is used.The hydrolysis rate of chloride ion reaches 90.9%,and 80%Ti O₂and C can be recovered.The harmless,resource-based and reduced treatment of chlorinated dust collection slag is realized,which has engineering significance and application value.The results are as follows(1)According to the theoretical basis of the reaction between the relevant components of chlorinated slag and water,the steam hydrolysis reaction of chlorinated dust collection slag was studied by analyzing the thermal efficiency of the reaction The calculation of?=W/Q shows that the hydrolysis reaction has little heat consumption and can be carried out at 0?500?.The hydrolysis of Mg C1₂occurs at 300?500?,and the molar ratio of HC1/H₂O is between 0?0.5.According to the gas-liquid equilibrium phase diagram of the binary system of HCl-H₂O,the co boiling point of hydrogen chloride is obtained.Theoretically,the concentration of recovered hydrochloric acid will not exceed 21%.According to the calculation of dew point temperature under different partial pressures of HCl-H₂O,the highest dew point temperature is 121?.(2)The steam hydrolysis behavior of pure substances of related components in raw materials was studied.Hydrochloric acid concentration and chloride ion hydrolysis rate of magnesium chloride steam hydrolysis increased with the increase of reaction temperature.The hydrolysis rate of chloride ion reached 92%at 250?.The hydrochloric acid concentration and chloride ion hydrolysis rate of manganese chloride basically flatten out to 97%after 300?.The study of combustion characteristics of petroleum coke shows that the combustion rate of petroleum coke reaches 95%at 450?.(3)The hydrolysis process of chlorinated slag was studied.The influencing factors of steam hydrolysis reaction temperature,reaction time,water vapor flow rate and air flow rate were studied to determine the optimal process parameters.The results show that when the reaction temperature is 350?,the reaction time is 30min,the water vapor flow rate and the air flow rate are 400L/h and 250L/h respectively when the cross-sectional area of the furnace is 9?cm²,more than 90%chlorine in the titanium tetrachloride slag is converted into hydrochloric acid.(4)After the treatment of hydrolyzed solid products,it was found that the p H value of 3 hydrochloric acid solution was the best medium for the treatment of solid powder after steam hydrolysis.The chlorine ion leaching amount of the treated residue is 150mg/L.at the same time,the petroleum coke in the light phase can be used as the raw material for carbon tetrachloride production after beneficiation,and the Ti O₂in the heavy phase can be used as the raw material for electrofusion smelting.The residual residue needs to be discharged only accounting for 24%of the amount of chlorinated dust collection residue,realizing the resource utilization and reduction of chlorinated dust collection residue.The treatment of chlorinated dust collection residue by steam hydrolysis mineral processing method can solve the problems of harmless,resource and reduction of chlorinated dust collection residue.