Method for preparing ferric chloride by quickly oxidizing iron dichloride

Abstract

The invention belongs to the chemical engineering technical field, in particular to a method for preparing ferric chloride by quickly oxidizing iron dichloride, the specific steps of which are as follows: the mixed liquor of iron dichloride solution crystal and hydrochloric acid or steely hydrochloric acid pickling solution is well stirred in a reactor in the room temperature, an injector and a circulating pump are used for causing the liquid to be in recurrent state, and then in the normal atmosphere condition, oxygen, sodium nitrite or nitric acid are added so as to realize the oxidation reaction of the iron dichloride solution and obtain liquid ferric chloride solution. If the liquid ferric chloride solution is further concentrated, the solid ferric chloride crystal can be obtained. The preparation method is simple, does not need chlorine to serve as the oxidant and is characterized by safety and high effective; meanwhile, raw materials are easy to be gotten, has low cost, extensive development valve and application prospect.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method for preparing ferric chloride by rapid oxidation of ferrous chloride. Background technique [0002] At present, many iron and steel processing units in my country use hydrochloric acid pickling process, and this part of waste acid has not been fully utilized yet. Usually, waste acid is reacted with iron filings to form ferrous chloride, and then reacted with chlorine gas to produce ferric chloride solution. Although ferric chloride solution is a highly corrosive inorganic coagulant, it is a very good coagulant in the iron salt series coagulant. [0003] In the way that ferrous chloride is oxidized to form ferric chloride, the mechanism of reaction of chlorine gas and ferrous chloride solution is widely used at home and abroad at present, for example: [0004] 2FeCl 2 +Cl 2 =2FeCl 3 (Formula 1) [0005] Because the pickling waste liquid often...

AI Technical Summary

Problems solved by technology

[0009] The use of chlorine gas oxidation has great advantages. For example, the speed of chlorine gas oxidation of ferrous ions is very fast, and there is no problem of introducing impurities. However, chlorine gas is a highly toxic first-class dangerous product, which has strict requirements for storage, transportation and use. Dozens of air leakage accidents occurred during the transportation and use of chlorine gas. Small accidents caused local air pollution and personnel poisoning, and major accidents often caused the transfer of thousands of residents or employees. Therefore, the use of chlorine gas has a very large Hidden danger