The invention relates to a production method of superfine
powder of
magnesium hydroxide by distilling
seawater. The method adopts desalted water as
raw material.
Calcium carbonate deposition is formed and separated out by adding precipitator
carbonate. Then filtrate that contains
magnesium is adopted as raw liquid and a proper amount of dispersant polyglycol 1000 is added, a mixture is formed. Then the mixture is driven into an ejector by a
centrifugal pump and reacts with alkali solution in a
static mixer. The alkali solution is driven by a
metering pump from an alkali solution tank into the
static mixer. A material, in which
solid material content is more than 15 percent, is made by concentration through a 10-100nm
ceramic ultrafiltration membrane. Then the material is washed until the washing
water conductivity permeating the
ceramic membrane is less than 200.0 Mus / cm. Finally, the
slurry of
magnesium hydroxide is dried by a spray drier. The technique of the invention is simple and has high
automation degree, high profit, but low cost, and is easy to be operated, and overcomes the problem of low
yield rate caused by the next two reasons that particle agglomeration of magnesium
hydroxide can not be controlled and the fine particles can not be closured by adopting the
conventional technique in prior art. Meanwhile, the concentration and the washing are realized in a
ceramic ultrafitration membrane unit, and the problem of particle agglomeration of the magnesium hydroxide caused by the existence of large quantities of
chloride ion is thoroughly solved.