中国有色冶金

The titanium containing blast furnace slag and titanium extraction waste liquid contain various valuable metals. Recycling and utilizing them can not only solve environmental pollution problems, but also improve enterprise profitability by preparing industrial products during the recycling process. According to the leaching process, the titanium extraction waste liquid can be divided into sulfuric acid titanium extraction waste liquid, hydrochloric acid titanium extraction waste liquid, ammonium sulfate roasting sulfuric acid titanium extraction waste liquid, and nitric acid titanium extraction waste liquid. The waste liquid from sulfuric acid titanium extraction contains a large amount of Al³⁺, which is often extracted to prepare aluminum ammonium sulfate and aluminum hydroxide, and the waste acid is recycled for comprehensive utilization. However, the method of preparing by-products has a low aluminum removal rate, and the filtration of the resulting Al(OH)₃ colloids is difficult; For hydrochloric acid titanium extraction waste liquid, precipitation method is often used to recover metal ions, but this method ultimately treats the waste liquid containing Cl^-, which cannot achieve green discharge; The comprehensive utilization of ammonium sulfate titanium extraction waste liquid is often achieved through solvent recovery, solvent recycling, leaching, and crystallization separation of components such as aluminum and silicon, which has good industrial application value. However, this process requires high equipment requirements, and the flocculation product is a gel like liquid, which is difficult to filter; The method of preparing aluminum hydroxide, calcium carbonate, magnesium carbonate by precipitation and ammonium nitrate fertilizer by evaporating the mother liquor is commonly used for comprehensive utilization of nitric acid extraction waste liquid. This method does not consume nitric acid in the acid leaching process and has a simple process, which has good application prospects. In the future, while focusing on the efficiency of titanium element extraction, this field should also develop recycling processes for other valuable elements, research and develop more environmentally friendly treatment technologies such as biological leaching and electrochemical leaching, reduce the generation of harmful by-products, and achieve a more sustainable treatment process.