Defluorination method for zinc sulphate solution

Abstract

The invention discloses a defluorination method for a zinc sulphate solution, comprising the following ordered steps of: A, a ball-milling process: milling coarse grains Ce2(CO3) with water by a ball mill, wherein the Ce2(CO3) is milled to have the grain size of less than 1 micrometer so as to form slurry, and the slurry is used for a sedimentation defluorination process; B, the sedimentation defluorination process: adding the slurry formed by the step A into the zinc sulphate solution with the pH value of 5.0-5.4, adding sulfuric acid to regulate the pH value to be 3.0-4.5, making the Ce2(CO3) react with the fluorine in the zinc sulphate solution to generate the CeCO3F sediment, wherein the concentration of fluorine ions in the solution is reduced to be less than 0.1g / L, the solution is filtered, the filtrate is used for regular zinc hydrometallurgy, and the filter residue is used for a sedimentation residue filtering and washing process; C, the sedimentation residue filtering and washing process: adding water for filtering and washing the filter residue obtained by the step B, wherein the filtered and washed liquid is used for the regular zinc hydrometallurgy, and the filtered and washed residue is sold. The method provided by the invention is featured by being short and easy, low in energy consumption, pollution free, low in technical operation difficulty, excellent in defluorination effect, low in operating cost, remarkable in economic benefits, 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, which is especially suitable for defluorination treatment of high-fluorine zinc sulfate solution. Background technique [0002] At present, metal zinc is basically produced by the hydrometallurgy process, which is because hydromethod zinc smelting has the characteristics of environmental protection, low cost and high recovery rate compared with pyromethod zinc smelting. However, in the hydrometallurgy process, the fluorine content in the electrolytic solution needs to be strictly controlled, if the fluorine content is too high (F - >0.1 g / L), the cathode zinc produced by electrolysis will stick to the cathode aluminum plate, causing production failures such as cathode zinc is difficult to peel off, resulting in a reduction in the production capacity of the enterprise, and even a standst...

AI Technical Summary

Problems solved by technology

The common methods for removing fluorine from high-fluorine raw materials include fire method and wet method. The fire method uses a rotary kiln or a multi-hearth furnace to roast the raw material to volatilize the fluorine in the raw material. Although this method is mature in technology, there is a relatively high energy consumption per unit. High, unsatisfactory removal effect and large pollution, this method is not ideal in the environment of rising global energy prices and advocating energy conservation and emission reduction; the wet method uses alkaline solution to wash the raw material to dissolve the fluorine in the raw material In solution, although this method has low energy consumption and good working environment, the process is complicated, and different process parameters are required for raw materials from different sources, so the operability is poor.

[0004] In order to overcome the above problems and develop a method with good operability, low energy consumption and ideal defluorination effect, various metal smelting enterprises and individuals have done a lot of research, such as "A fluorine absorbing agent for electrolyte in zinc electrolytic smelting and a method for removing fluorine using a fluorine absorbing agent" disclosed in Chinese patent literature (publication number: CN101001693, publication date: 2007.07.18), which discloses four types of zinc The fluorine absorbing and desorbing agent for the electrolyte and the fluorine removal method using the fluorine absorbing and desorbing agent are respectively alkaline ferric sulfate fluorine absorbing and desorbing agent, ferric peroxyhydroxide fluorine absorbing and desorbing agent, iron oxide fluorine absorbing and desorbing agent, hydrogen Iron oxide fluorine absorbing agent, due to the limited ability of the absorbing agent to absorb fluorine, the amount of fluorine absorbing agent used is huge, a large amount of waste water is generated during desorption, the pollution is serious, and the process is long, the investment in equipment is large, and the production cost of the enterprise High; another example is the "Fluorine and Chlorine Removal Technology by Ion Exchange Method for Zinc Wet Metallurgy Industrialization" disclosed in Chinese patent literature (publication number: CN101492772, publication date: 2009.07.29), which adopts the adsorption and desorption cycle process of anion exchange resin D201, Removing the fluorine in the high-fluorine zinc sulfate solution, this method is similar to the technology with the publication number CN101001693, and has the disadvantages of large wastewater discharge and serious pollution during desorption; another example is the "zinc sulfate solution defluorination process" disclosed in Chinese patent documents (Publication No.: CN1966407, Publication Date: 2007.05.23), which discloses a method of producing Al2(PO3F)3 precipitate A method for removing fluorine in a high-fluorine zinc sulfate solution, the method adopts Al2(SO4)3·12H2O and Na3PO4 · 12H2O as raw materials, there are large amounts of raw materials added, large amount of slag and zinc sulfate solution Disadvantages of large loss of zinc

[0005] To sum up, at present, my country's metal smelting industry is deeply troubled by excessive fluoride ions in hydrometallurgy, and lacks a good solution. A Simple, Pollution-free, Economical, Reliable and Practicable Method for Removing Fluoride in Zinc Sulfate Solution

Images