Method of extracting bromine from bromine-bearing liquids or wastewaters

Abstract

The invention discloses a method of extracting bromine from bromine-bearing liquids or wastewaters. The method includes the steps of (1) acidifying a bromine-bearing liquid or wastewater, and introducing chlorine into the acidified liquid to oxidize bromine ions into free bromine so as to obtain an oxidized liquid; (2) feeding both the oxidized liquid and an extracting agent into a centrifugal extractor to carry out counter-current extraction so as to obtain extract and raffinate; (3) feeding both the raffinate and a stripping agent solution into the centrifugal extractor to carry out counter-current stripping so as to obtain hydrobromic acid-bearing absorption liquid and the extracting agent; (4) feeding the absorption liquid into a distilling column, introducing chlorine into the absorption liquid, generating hydrogen chloride and free bromine by reaction of the chlorine with hydrobromic acid in the absorption liquid, allowing the hydrogen chloride to turn into hydrochloric acid uponcontact with water, and distilling the free bromine during distilling to obtain finished bromine. The method herein is continuous, high in automation level, high in establishment speed of phase balance, and low in extracting agent consumption.

Description

technical field [0001] The invention relates to a method for extracting bromine from bromine-containing material liquid or waste water. Background technique [0002] Bromine is widely used in modern chemical industries such as pesticides, medicines, petroleum, and dyes. It is an important chemical raw material for the production of flame retardants, fire extinguishing agents, and photosensitive materials. A wide variety of inorganic bromides and organic bromides derived from it are in the national It plays a special role in economic and technological development. Bromine mainly exists in the ocean, oil and gas field water, underground brine and salt lake brine, and also exists in the feed liquid or wastewater of some chemical plants. [0003] The traditional bromine extraction methods are steam distillation and air blowing. The steam distillation method uses chlorine gas to oxidize the bromine ions in the bromine-containing liquid or waste water into elemental bromine, and...

AI Technical Summary

Problems solved by technology

Carbon tetrachloride is resistant to bromine and chlorine oxidation, but it is banned as an ozone-depleting substance. Other halogenated hydrocarbons and halogenated aromatics are highly toxic and easily cause environmental pollution.

The traditional solvent extraction method generally uses a box-type mixing and settling tank extraction method, which has the following disadvantages: 1. The extraction process requires a large amount of organic phase, the volume of the organic phase that needs to be filled in the extraction tank is large, and the extraction tank occupies a large area; 2. 1. The extraction efficiency is low, the total flux of the extraction tank is small, and the processing capacity of the feed liquid is small; 3. The number of stages required is large, and it is difficult to obtain high-purity products; 4. It takes a long time to re-establish phase equilibrium; 5. The raffinate during the extraction process The organic phase in the

The above reasons have hindered the popularization and application of solvent extraction in the process of extracting bromine

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