利用钛白废酸浸出钛石膏铁杂质及技术经济分析

Study on extraction of iron oxide from leaching titanium gypsum using titanium dioxide waste acid and technical&economic performance

钛石膏与钛白废酸是钛白粉生产过程中的副产品,其综合利用一直是难题。为了解决此难题,提出了用钛白废酸浸出钛石膏、浸出的滤渣干燥后成为去铁石膏(白石膏)、含铁滤液经过结晶处理得到绿矾的综合利用途径。通过热力学计算分析了实验原理,并在原料分析的基础上进行了优化浸出工艺条件试验,结果表明:在反应温度为70℃、废酸稀释比(酸水比)为1∶2、固液比为1∶7.5(g/mL)的条件下,铁的浸取率可高于90%。最后对此工艺进行了技术经济分析,结果表明,采用此工艺可以达到低成本、短流程大量消解堆存钛石膏的目的。

Titanium gypsum and titanium dioxide waste acid are by-products resulted from the production of titanium dioxide,and their utilization has become a hard job.To come up with a solution to this problem,a process for the utilization was presented,which includes leaching titanium white gypsum with titanium dioxide waste acid,drying the residue from leaching process to obtain iron free gypsum(white gypsum),crystallization of the iron-bearing filtrate to produce ferrous sulfate.The experimental principle was studied with thermodynamic calculation,and the experiments on optimization of leaching process conditions were carried out on the basis of chemical analysis of raw materials.The results show that the iron leaching rate of over 90%can be achieved at reaction temperature of 70℃with a dilution ratio(waste acid to water)of 1∶2 and solid-liquid ratio(g/mL)of 1∶7.5.Finally,the technical and economic analysis of this process was conducted and the results indicate that the application of this process in massive decomposition of stockpiled titanium gypsum is featured by low cost and simple process flow.