Method for extracting bromine-magnesium compound from Grignard reaction wastewater and mother liquor

Abstract

The invention relates to a method for extracting a bromine-magnesium compound from Grignard reaction wastewater and mother liquor, and belongs to the technical field of Grignard reaction wastewater and mother liquor treatment. The method comprises the following steps: adding composite alkali into the Grignard reaction wastewater and mother liquor for distillation and ammonia removal; performing solid-liquid separation on the ammonia-removed wastewater twice, and performing water washing and drying to obtain Mg(OH)2; mixing supernatant obtained after the two times of solid-liquid separation, acidifying, heating for evaporation, and cooling to obtain a bromine-magnesium compound solid product. According to the method, the composite alkali is added for evaporation to remove ammonia, solid-liquid separation is performed twice, the solid phase is washed with water and dried, and the liquid phase is acidified, evaporated and crystalized to obtain high-purity high-value Mg(OH)2, MgBr2.6H2O and MgCl2.6H2O. The method has high yield and high purity, and is suitable for industrial amplification, the problem of wastewater discharge is solved, and the valuable bromine-magnesium compound can beextracted efficiently.

Description

technical field [0001] The invention relates to the technical field of Grignard reaction wastewater and mother liquor treatment, in particular to a method for extracting bromine-magnesium compounds from Grignard reaction wastewater and mother liquor. Background technique [0002] Grignard reaction, as one of the most industrially valuable organic chemical reactions, was invented by French scientist Victor Grignard in 1899 and won the Nobel Prize in Chemistry in 1912. In anhydrous solvents (generally anhydrous ether, tetrahydrofuran), magnesium can react with halogen compounds of many aliphatic hydrocarbons and aromatic hydrocarbons to form magnesium organic compounds, which is called Grignard reaction, generally expressed as follows. Because the reactivity of haloalkyl groups varies, it is generally necessary to use elemental iodine as the initiator. [0003] The Grignard reaction is mainly used to construct the combination of carbon-carbon bonds. The main functional groups...

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Problems solved by technology

At present, the yield of most Grignard reactions is greater than 75%. Due to the following factors: after a long induction period, adding haloalkanes, iodine tablets or heating at the same time in advance, the reaction that has actually started slowly is suddenly accelerated, and excessive iodine is added after the reaction stops. The flakes will react violently and exothermic. In addition, the complexity of the reaction of some halogenated benzene and polyhalogenated methylbenzene compounds will produce by-products, which will cause the reaction yield to decrease.

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