Method for efficiently removing fluorine ions in manganese sulfate solution

Abstract

The invention provides a method for efficiently removing fluorine ions in a manganese sulfate solution. The method is characterized in that a certain quantity of to-be-processed manganese sulfate solution is added into reaction equipment, the content of the fluorine ions in the solution is measured, solid cerium hydroxide with a certain fluorine ion content proportion is added under the conditionsthat the temperature is 30-50 DEG C and the pH value is 2-6, the material is stirred for 8-12 h at the rotational speed of 150-350 r / min, then stirring is stopped, the material is left to stand for 12-18 h and then transferred into filtering equipment for filtration, the filtrate is a fluorine-removed qualified manganese sulfate solution, filter cake is added into reverse osmosis water at a solid-liquid mass ratio of 1:(1-6), stirring and washing are performed for 0.5 h, and filtering is performed to obtain fluorine-containing cerium hydroxide which is then fed into a regeneration procedure.According to the method, lots of residual fluorine ions in a manganese sulfate solution system can be removed, the content of a fluoride in the processed solution can be reduced to 100 ppm or below, and the fluorine removal agent cerium hydroxide can be recycled after being regenerated, so that the production cost is greatly lowered.

Description

technical field [0001] The invention relates to a method for removing impurities, in particular to a method for removing fluoride ion impurities in a metal salt solution, and more particularly to a method for efficiently removing fluoride ions in a manganese sulfate solution. Background technique [0002] As the most common manganese salt solution, manganese sulfate solution is widely used in battery industry and electrolytic manganese metal industry. At present, manganese sulfate in my country is mainly made of manganese ore leached by sulfuric acid and then removed from impurities. In the commonly used manganese sulfate production process, in order to remove metal ions such as calcium and magnesium, one or more of manganese fluoride, zinc fluoride, sodium fluoride, potassium fluoride and ammonium fluoride are usually used as additives to remove Removal of calcium and magnesium ions, such as the technical solutions disclosed in Chinese Patent Publication Nos. CN101875507A,...

AI Technical Summary

Problems solved by technology

[0003] In existing industrial production, the commonly used method for removing fluoride ions in manganese sulfate solution is to add milk of lime, that is, to make calcium hydroxide and fluoride ions form insoluble calcium fluoride, which is then adsorbed by silicon dioxide in the solution; The disadvantage of this method is that in the process of adding milk of lime, the local pH value of the solution will be greater than 7, which will easily cause the loss of manganese sulfate, and the insoluble calcium fluoride formed when the pH is less than 6 will reverse dissolve, resulting in the removal of fluorine. Ions exist in the solution in the form of ions, so it is difficult to reduce the fluoride ion in the manganese sulfate solution to below 100ppm by this method

[0004] The Chinese patent application with the application number 201210084081.9 discloses a method for removing fluoride ions in manganese sulfate solution for the production of electrolytic manganese metal. The disadvantages are: (1) the use of calcium carbonate under acidic conditions will introduce calcium ions into the manganese sulfate solution, resulting in a high residual calcium ion in the solution; (2) the operating temperature is high, and the manganese sulfate solution is mostly Acidic solution, the use of calcium carbonate in an acidic environment will produce a large amount of carbon dioxide, there are certain safety hazards

[0005] The Chinese patent application with the application number 201510260553.5 discloses a method for removing fluoride ions in a high-purity manganese sulfate solution. The disadvantages are: (1) The rare earth sulfate salt has a certain solubility in the aqueous system. Although the introduction of the rare earth sulfate salt into the acidic system can inhibit its hydrolysis, it will still cause one or more rare earth ions Residues in the manganese sulfate solution will affect the use of manganese sulfate solution, and even cause damage to production equipment; (2) Rare earth is a non-renewable mineral resource with high economic value, its recycling is of great significance, and the use of rare earth in this plan The amount is large and the used rare earth sulfate has not been recovered, and the defluoridation agent cannot be recycled effectively, fully and environmentally friendly, and the cost is high; (3) This scheme is used in the treatment of sulfuric acid containing high concentration of fluoride ions (> 1000ppm) When manganese solution is used, more rare earth sulfate salts must be added, which will cause a large amount of rare earth ions to remain in the manganese sulfate solution, and the remaining rare earth ions, especially those with +III valence, need to be removed by adding oxalate or adjusting High pH value causes rare earth ions to precipitate, and this process will produce manganese oxalate precipitation or trigger hydrolysis reaction to produce manganese hydroxide precipitation, resulting in the loss of manganese sulfate material, so this technology is difficult to use in practice

[0006] At present, for the manganese sulfate solution system with high concentration of fluoride ion residues in actual production, the fluoride treatment process is not yet mature, which severely limits the industrial application of manganese sulfate solution