Method for harmlessly treating and recycling magnesium fluoride waste acid in zinc smelting process

Abstract

The invention relates to a method for harmlessly treating and recycling magnesium fluoride waste acid in a zinc smelting process. The method comprises the following steps of (1) harmlessly recycling the waste acid; (2) removing magnesium from a desorbed solution, adding a seed crystal, a modifier, a magnesium removal agent, lime and the like into the desorbed solution, heating, stirring and filtering to obtain a magnesium-removed solution and magnesium fluoride concentrate, adding tannic acid into the magnesium-removed solution to precipitate germanium, recovering germanium, filtering to obtain tannin germanium slag and a germanium-precipitated solution, firing the tannin germanium slag to obtain germanium concentrate, and feeding the germanium-precipitated solution to leached air for oxygen purification to remove iron and fluorine; (3) removing iron and fluorine from the germanium-deposited liquid through air oxidation; and (4) dechlorinating the liquid copper slag after iron and fluorine removal. According to the method, magnesium oxide is opened, harm of the magnesium oxide in a zinc hydrometallurgy solution system is reduced, and magnesium, fluorine and acid are recycled harmlessly; active agent is added, a problem of colloid formation in high zinc solution is solved, characteristics of the magnesium fluoride slag in the high zinc ion solution are changed, so that the magnesium fluoride slag formed a spongy structure and was easy to separate liquid from solid.

Description

technical field [0001] The invention belongs to the technical field of nonferrous metallurgy, and in particular relates to a method for harmlessly treating and recovering magnesium-fluorine polluted acid in a zinc smelting process. Background technique [0002] With the continuous impoverishment of zinc mineral resources and the continuous improvement of national environmental protection awareness, it actively responds to the requirements of national environmental protection and comprehensive recycling of limited resources and sustainable development. [0003] In the production process of zinc hydrosmelting, the raw materials used generally contain about 0.5wt% magnesium oxide, and even some raw materials contain about 3.0wt% magnesium oxide. Such raw materials cause great difficulties to the production of zinc hydrosmelting. Magnesium ions are a continuous accumulation process in production, and the saturation is different under different conditions. Magnesium ion salts en...

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Problems solved by technology

[0005] The existing problems include: (1) the high-magnesium ion salt causes great difficulties in the production of zinc by hydrometallurgy; (2) the polluted acid is directly neutralized by lime, which causes a waste of acid and fluorine resources; (3) in the treatment A large amount of sulfur dioxide gas will be released during the process, causing environmental pollution and occupational health hazards

[0008] (1) Neutralizing zinc-precipitating and magnesium-expelling method. This method uses lime to hydrolyze and precipitate zinc into the slag, and the magnesium is left in the solution to be discharged, realizing the separation of zinc and magnesium, but the large amount of gypsum slag produced will cause secondary pollution. , magnesium resources and water resources cannot be recycled;

[0009] (2) Zinc ore pickling and magnesium removal method, this method can only remove part of the magnesium, and some valuable metals will also be pickled out, which is difficult to recycle, resulting in the loss of valuable metal resources;

[0010] (3) concentrated crystallization separation magnesium method, this method zinc, magnesium separation effect is not good enough, and magnesium still stays in solution;

[0011] (4) High-efficiency extractant separation zinc and magnesium method, this method can realize the high-efficiency separation of zinc and magnesium, but the equipment is complicated and the cost input is high

This method will directly cause the loss of acid and fluorine, resulting in waste of resources. The key point is that a large amount of sulfur dioxide gas will be released during the treatment process, causing environmental pollution and occupational health hazards.

[0023] In short, in the high zinc solution using traditional fluoride to remove magnesium, the magnesium fluoride crystal particles are too fine and the viscosity is too high. In the case of magnesium fluoride crystals as seeds, although the magnesium fluoride crystal particles will increase Large, but it is also easy to form colloids in such a high-zinc solution, which makes sedimentation very difficult, and the solution has poor filtration performance, or even cannot be filtered, so it is difficult to apply to actual production

It can be seen that there is still no good and practical method to solve the comprehensive treatment of high zinc, high magnesium and dirty acid in the zinc hydrometallurgy process. In view of the above problems, it is necessary to invent a method for harmless treatment and recycling Magnesium Fluorine Polluted Acid Method

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