Method for removing fluorine from zinc sulfate solution after roasting of zinc smelting silicon residues

Abstract

The invention discloses a method for removing fluorine from a zinc sulfate solution after roasting of zinc smelting silicon residues. The method comprises the following steps that A, the silicon residues are prepared, specifically, the silicon residues generated in the zinc hydrometallurgy process are roasted under the condition of 300-650 DEG C; B, sediment defluorination is conducted, specifically, the roasted silicon residues obtained in the step A are added into the zinc sulfate solution with the pH value no larger than 5.0 and washed at a room temperature till the concentration of fluorine ions in the solution is decreased to 60-80%; C, the sediment residues are subjected to alkaline cleaning, specifically, the residues obtained in the step B are subjected to alkaline cleaning, and the fluorine ions adsorbed to the silicon residues are desorbed; and D, alkaline cleaning residues are washed, specifically, the alkaline cleaning residues obtained in the step C are washed through clear water to enable zinc in the residues enter an aqueous solution to be recycled, and the washed residues are continuously defluorinated. By adoption of the method, the number of cyclic times can reach 40 or above, and the defluorination effect can still be kept at 50% or above. The method has the advantages of being extensive in raw material resource, short in technological process, easy to operate, high in defluorination rate, low in operation cost, remarkable in economic benefit and the like.

Description

technical field [0001] The invention belongs to the field of hydrometallurgy in nonferrous metallurgy, and in particular relates to a method for removing fluorine in zinc sulfate solution after roasting zinc smelting silicon slag, and is especially suitable for defluorination treatment of high-fluorine zinc sulfate solution. Background technique [0002] At present, more than 80% of zinc smelting is carried out by wet process (roasting-leaching-purification-electrowinning). With the continuous development and improvement of hydro-metallurgy zinc process, some smelters have adopted zinc sulfide concentrate oxygen pressure leaching and Atmospheric pressure oxygen-enriched leaching process realizes real full-hydro zinc smelting. With the decline of mineral resources in recent years, the raw material zinc concentrate used by zinc smelters is of low grade, complex and high content, and the content of fluorine and chlorine in the raw material is very high. For zinc hydrometallurg...

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Problems solved by technology

[0003] In order to solve the above problems, many scientific researchers have done a lot of research on this. Some researchers have shown that silica gel has the ability to remove fluorine. It is believed that silica gel mainly interacts with fluorine in acidic solution in the state of hydrogen fluoride through the adsorption of surface porous structure. Silica gel polymerization, but the removal rate of this method can only reach 30-60%

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