Method for deeply purifying titanium dioxide copperas

Abstract

The invention belongs to the field of comprehensive utilization of titanium dioxide byproducts, and particularly relates to a method for deeply purifying titanium dioxide copperas. The technical problem to be solved by the invention is to provide a method for deeply purifying titanium dioxide copperas, and the method comprises the following steps of: A. dissolving a titanium dioxide byproduct copperas in sulfuric acid, adding iron powder, performing heating to boiling, keeping boiling, and carrying out solid separation to obtain a liquid 1; B. adding ammonium hydrogen sulfide or ammonium sulfide and ammonium phosphate into the liquid 1, adding ammonia water to adjust the pH value to 3-4, adding a flocculating agent, performing aging for layering, and conducting separating to obtain a liquid 2; and C, adding sulfuric acid into the liquid 2 to adjust the pH value to 2-3, conducting heating, concentrating, cooling and crystallizing to obtain the high-purity ferrous sulfate. According to the basic principle that the solubility of a double salt is smaller than that of a single salt, magnesium ions are precipitated and separated in the form of the double salt, deep separation of magnesium ion impurities is achieved, and the method has the advantages of simple process, high iron yield and good impurity removal effect.

Description

technical field [0001] The invention belongs to the field of recovery of by-products of titanium dioxide, and in particular relates to a method for deep purification of titanium dioxide greenite. Background technique [0002] At present, my country produces about 3 million tons of titanium dioxide per year, most of which are produced by the sulfuric acid method. Every ton of titanium dioxide produced from titanium concentrate will produce about 3.5 tons of by-product ferrous sulfate. According to incomplete statistics, the national The by-product of titanium dioxide, ferrous sulfate, is as high as 5 million tons per year, because it contains TiO 2+ , Mn 2+ , Mg 2+ 、Al 3+ Such a large amount of ferrous sulfate by-products not only affects the environment, but also wastes iron resources, which largely restricts the development of the titanium dioxide industry. develop. At present, ferrous sulfate is mainly used as water purifier, feed additive, fertilizer, paint, etc., but...

AI Technical Summary

Problems solved by technology

The main disadvantage of this method technology is that the purification effect is limited, especially for the high vitriol raw material effect of impurity content, because in the ferrous sulfate salting-out process, impurities such as magnesium sulfate / manganese will also be salted out simultaneously, resulting in product The impurity content is high, and the salting-out process needs to be repeated for further analysis of impurities, which further causes a large loss of ferrous iron and low yield

The main disadvantage of this method is to use fluoride to precipitate magnesium ions in ferrous iron, but ferrous fluoride and magnesium fluoride are both slightly soluble, and the selectivity is poor. To remove magnesium, a large amount of iron must be precipitated at the same time. And the amount of fluoride is also relatively large, which greatly increases the cost of raw materials

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