Method and equipment for extracting bromine from seawater by using air blowing method

Abstract

The invention discloses a method and equipment for extracting bromine from seawater by using an air blowing method. The method comprises the following steps: introducing sulfuric acid and chlorine gasinto seawater, and reacting bromine ions into free bromine; introducing a raw material solution containing free bromine from a blow-off tower, spraying downwards through a liquid distributor, introducing air from the lower portion of the blow-off tower, and performing countercurrent contact with the raw material solution containing free bromine in the blow-off tower; introducing air carrying freebromine, an absorption liquid circulated from the bottom of an absorption tower and sulfur dioxide gas introduced from the outside from the top of the absorption tower together in a forward flow manner, and reacting to generate a hydrobromic acid-containing absorption liquid; discharging the absorption liquid from the bottom of the absorption tower, circularly introducing the absorption liquid into the top of the absorption tower through a pump, discharging the free-bromine-removed air from the lower portion of the absorption tower, and sending the air out of the blow-off tower so as to be recycled after the entrained liquid foam is removed; and sending the finished liquid to a distillation tower, oxidizing again, distilling, condensing, and refining to obtain liquid bromine. The method is suitable for transformation of the existing bromine extraction device or newly-built bromine extraction devices, bromine extraction energy consumption is effectively reduced, investment is reduced,and economic benefits are improved.

Description

technical field [0001] The invention relates to a bromine extraction technology, in particular to a bromine extraction method and equipment which use seawater as a raw material and mainly use structured packing. Background technique [0002] Bromine is widely used in pesticides, pharmaceuticals, petroleum industry, fuel and other industries, and is one of the basic chemical raw materials for the production of flame retardants, fire extinguishing agents and photosensitive materials. In my country, underground brine in Shandong is mainly used as raw material, and bromine is extracted by air blowing method. For example, the authorized patent 201210524036.X proposes a method for extracting bromine in brine. However, as the total amount and grade of underground brine are decreasing day by day, only using brine as a raw material to extract bromine can no longer meet the increasing demand for bromine in my country. On the other hand, because brine has many impurities and high salt...

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Problems solved by technology

[0003] Aiming at the defects that the sources of bromine resources in the existing bromine extraction industry are decreasing day by day, and the energy consumption for extracting bromine is high, the present invention provides a method and equipment for extracting bromine from seawater (i.e. the method and equipment for extracting bromine from seawater by air blowing method) equipment), can make full use of the advantages of low salt concentration in seawater, clean water without scaling, and large total bromine storage to replace the original underground brine as a new source of bromine resources, and at the same time make full use of structured packing with large specific surface area, high porosity, It replaces the stepped ring in the traditional bromine extraction packed tower with the advantages of sufficient gas-liquid two-phase contact and high mass transfer efficiency, and optimizes the internal parts of the tower such as liquid distributor and gas distributor, which can effectively reduce the energy consumption of bromine extraction , to increase the output of a single tower

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