A kind of method for recovering magnesium fluoride polluted acid by harmless treatment in zinc smelting process

Abstract

The invention relates to a method for harmless treatment and recovery of magnesium fluoride polluted acid in a zinc smelting process, comprising: 1) harmless reuse of polluted acid; Seeds, modifiers, demagnesiasing agents, lime, etc., heat up and stir, filter to obtain demagnesium solution and magnesium fluoride concentrate, add tannic acid to the demagnesium solution to precipitate germanium, recover germanium, and filter to obtain germanium tannin Slag and germanium precipitation liquid, tannin and germanium slag are burned to obtain germanium concentrate, and the post germanium precipitation liquid is sent to leaching air for oxygen purification to remove iron and fluorine; 3) air oxidation to remove iron and fluorine after germanium precipitation; 4) iron removal After fluorine, the liquid copper slag is dechlorinated. The invention achieves the open circuit of magnesium oxide, reduces the harm of magnesium oxide in the hydrometallurgical zinc solution system, and recovers magnesium, fluorine and acid harmlessly; by adding active agent, the problem of easy formation of colloid in high zinc-containing solution is solved, and fluorine is changed. The characteristics of magnesium fluoride slag in high zinc ion solution make magnesium fluoride slag form a spongy structure, which is easy for liquid-solid separation.

Description

technical field [0001] The invention belongs to the technical field of non-ferrous 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 barrenness 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 and sustainable development of limited resources. [0003] In the production process of zinc hydrometallurgy, the raw materials used generally contain about 0.5wt% of magnesium oxide, and even some raw materials contain about 3.0wt% of magnesium oxide. Such raw materials cause great difficulties to the production of zinc hydrometallurgy. Magnesium ion is a continuous accumulation process in production, and the saturation is different under different conditions. Magnesium ion sal...

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Problems solved by technology

[0005] The existing problems include: (1) The high magnesium ion salt has caused great difficulties in the production of zinc by hydrometallurgy; (2) The contaminated acid is directly neutralized with lime, resulting in 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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