Method for preparing ferric chloride through rapid oxidation of ferrous chloride

Abstract

The invention relates to the technical field of chemical engineering, in particular to a method for preparing ferric chloride through rapid oxidation of ferrous chloride. The method comprises the following steps: conveying chlorine into a reactor to react with an atomized ferrous chloride solution to obtain a ferric chloride solution; mixing P507, methyl tert-butyl ether and cyclohexane, adding into a ferric chloride solution, stirring, separating out an organic phase, adding a hydrochloric acid solution into the organic phase, stirring, and separating out a water phase; heating and evaporating the water phase, introducing nitrogen for protection when crystals appear in a solution, cooling and crystallizing, standing and filtering, leaching a filter cake by using cyclohexane, and drying under reduced pressure, thereby obtaining the product. According to the method, ferrous chloride atomized and then subjected to convection reaction with chlorine gas for rapid oxidation is adopted, so that the oxidation reaction is more sufficient and thorough, and the method has the characteristics of high efficiency, rapidness and safety; after extraction and back extraction, the yield of ferric chloride is reduced to a small extent, the purity is greatly improved, so that the method has a positive effect on recycling iron ions in the steel hydrochloric acid pickling waste liquid.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a method for rapidly oxidizing ferrous chloride to prepare ferric chloride. Background technique [0002] At present, many iron and steel processing units in my country use hydrochloric acid pickling process. This part of waste acid has not been fully utilized at present. This high-concentration waste liquid is directly discharged into rivers, which has an impact on the local ecological environment, urban water use and farmland irrigation water. It cannot be ignored that the current general recycling method is to react waste acid with iron filings to form ferrous chloride, and then react with chlorine gas to produce ferric chloride. Although ferric chloride is a highly corrosive inorganic coagulant, it is a very good coagulant in the iron salt series coagulant. [0003] However, due to the addition of Fe in the waste liquid of iron and steel hydrochloric acid pickling ...

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Problems solved by technology

[0003] However, due to the addition of Fe in the waste liquid of iron and steel hydrochloric acid pickling 2+ Also contains other impurity metal ions in addition, causes the ferric trichloride purity that finally obtains is not high, and impurity is more, in view of this, the present invention proposes a kind of ferrous chloride fast oxidation method for preparing ferric chloride, the obtained Ferric chloride has high purity and less impurities, and it is used as an inorganic coagulant with better coagulation effect

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