Treatment method for waste acid containing iron and zinc and water purifying agent and zinc product obtained through treatment method

Abstract

The invention provides a treatment method of waste acid containing iron and zinc and a water purifying agent and a zinc product obtained by the treatment method, and relates to the technical field of chemical engineering. According to the treatment method, iron and zinc in the stock solution are directly separated in a solvent extraction mode, iron and zinc in the stock solution are completely separated, and the quality of the obtained product is stable. Meanwhile, in the waste acid treatment process, zinc ions in an organic phase are separated out through a detergent, other acid-base raw materials do not need to be consumed in the process, and meanwhile new impurities cannot be introduced into backwashing liquid. Moreover, when the stock solution is treated by the method, industrial equipment can be continuously operated, so that the production efficiency of the water purifying agent and the zinc product raw material is relatively high, meanwhile, the production cost is low, and the production process is environment-friendly. Besides, by means of the treatment method, the water purifying agent and the zinc product which are high in use value can be obtained from the waste acid, the value of the waste acid is maximized, the principle of recycling, reducing and harmlessness is met, and the environmental protection property is higher.

Description

technical field [0001] The invention relates to the field of chemical technology, in particular to a method for treating iron and zinc-containing waste acid and a water purifying agent and zinc products obtained therefrom. Background technique [0002] At present, the waste acid containing zinc and iron mainly comes from the galvanizing plant. Before the galvanizing or spraying starts, the rust and oxide film on the steel surface need to be pickled, and the unqualified steel needs to be backwashed with hydrochloric acid. The galvanized layer on the surface is subjected to zinc removal treatment. When the hydrochloric acid content of the two is reduced to a certain concentration, it can no longer be used and becomes waste liquid. This type of waste liquid generally contains high concentrations of hydrochloric acid, ferrous chloride and zinc chloride. It has good utilization value and application prospect. However, due to the difficulty of the separation process of iron and z...

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Problems solved by technology

The disadvantage of this method is that not only the amount of solid slag is large, it is difficult to handle, and it is easy to cause secondary pollution, but also the precious resources in the waste liquid cannot be fully utilized, and the dual purposes of protecting the environment and recycling resources cannot be achieved.

Another method is to use reducing iron powder, zinc powder or a mixture of the two to replace the heavy metal ions in the waste acid to achieve the purpose of purifying the waste acid, and then use the volatility of hydrochloric acid at a higher temperature to replace the hydrochloric acid with concentrated sulfuric acid. However, the waste liquid produced by this method is not easy to handle, and the process is more complicated, and the exothermicity of the reaction and the volatility of hydrochloric acid are not conducive to the recovery of hydrogen chloride gas.

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