Method for recovering scandium and titanium in titanium white wastewater

Abstract

The invention discloses a method for recovering scandium and titanium from wastewater in the production of titanium white powder. The method comprises the following steps of: carrying out single stage extraction in titanium white wastewater with P2O4, TBP and kerosene, wherein a phase ratio O / A is 1:50 to 1:10, and balance time is 10-20 min; then, stripping with alkali, filtering and dissolving a stripped substance with acid; heating a solution in a reaction kettle, adjusting a pH value, hydrolyzing titanium, filtering and recovering titanium, repeating the above process to process supernatant fluid, secondarily extracting and dissolving a stripped substance alkali cake with acid; precipitating scandium with oxalic acid and burning to obtain scandium oxide with the purity of 95 percent; and further refining to obtain high-pure scandium oxide. In the invention, titanium is recovered under the condition of ensuring scandium recovery without adopting a titanium washing process of sulfuric acid and hydrogen peroxide, and a hydrolysis mode is adopted to recover titanium, and the recovery cost of scandium is decreased. In addition, a degreasing device and oil-absorbing felt are adopted in waste liquid generated after extraction. The invention has the advantages of environmental protection and simple process, the wastewater contains the organic phase of less than 50 mg / l and reaches an emission standard.

Description

technical field

[0001] The invention relates to a method for recovering valuable elements in industrial waste water, in particular to a method for recovering scandium and titanium and purifying scandium oxide from titanium white waste water produced in the production process of titanium dioxide. Background technique

[0002] Scandium is a rare element, which is mainly extracted from other minerals, such as rare earth ore, ilmenite, bauxite, tungsten ore, etc. With the expansion of the civilian application of scandium, a large amount of cheap scandium is needed. The cost is high, and a large amount of scandium is lost from the titanium dioxide wastewater without recycling. There are two main production methods of titanium dioxide (titanium dioxide): chloride method and sulfuric acid method, and sulfuric acid method is mainly used in my country; in the process of producing titanium dioxide by sulfuric acid method, a large amount of waste acid water will be generated, and every...

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