Caustic soda production process.
2017-04-26 12:26:07

The caustic soda flake caustic soda is an alias, sodium hydroxide, sodium hydroxide in the industry known as the industrial base, caustic soda, caustic, according to existing forms can be divided into liquid, alkali, alkali protopine, solid particle. The protopine, solid alkali, alkali particles are three forms of solid sodium hydroxide.

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 The following chart, followed by caustic soda solid alkali alkali lye particle: 1 from 32% to 61% concentration, this stage in film evaporator. The heating source adopts medium pressure steam and two steam, and is evaporated under vacuum. 2.61% by lye falling film concentrator, using molten salts as heat carrier, will be concentrated into molten alkali lye under atmospheric pressure, and then made the solid caustic soda flake caustic soda machine (molten salt method in the legend). The mass fraction of ionic membrane caustic soda by 32% 1 evaporator (vacuum, two times concentrated to 47% by steam) pump and steam condensate and II evaporator heat exchanger, in the second evaporator further concentrated to 61%, and by 61% in the final of pump alkali concentrator, molten salt heating to concentrate from 98% to 99%, and then made the solid caustic soda flake caustic soda machine. Since the 1 MPa saturated steam power plant to enter the first effect evaporator, condensate and alkali heat I effect after entering the recycling pool, as water supplement, two steam generated II effect and the final concentration of the two steam in the first evaporator as a heat source, 32% alkali evaporation. 415 ~ 430 DEG C molten salt by the molten salt pump into the molten salt furnace into the final concentrator after heating, as heat source alkali evaporation to 98% ~ 99%, and finally back to the molten salt tank, recycling. Molten salt furnace system is a system of closed loop heating by burning furnace, heating coil heating and above the molten salt with the ignition of gas through the pump head, the molten salt cycle in circulation in the system, and because of isolation, minimizing the decomposition of molten salt. In the production of primary heating molten salt should pay attention to the following points. (1) the melting point of molten salt is about 143 DEG C, and the molten salt pipeline should be accompanied by steam. It is better to use the electric heating to prevent the molten salt from freezing in the pipeline. (2) in molten salt gradient heating process, to carefully check valve with hot molten salt, molten salt proceed big circulation in the whole system, especially the small circulation valve is not closed, must rotate in a circle, in order to prevent the molten salt valve die. (3) the molten salt mixture, density is not very uniform, but the initial heating and melting, the moisture content in molten salt is higher, so in the molten salt circulation process, should pay attention to the pump current, if the pump current fluctuation, and lasts for a long time, should immediately stop the pump check, identify the reasons for the problem. Under normal circumstances, the pump current will fluctuate, but the wave

With the increase of molten salt temperature, pump current will gradually decrease and tend to be stable. Caustic soda as a basic chemical raw materials, widely used in papermaking, synthetic detergent and soap, viscose, rayon and cotton and textile industry, pesticides, dyes, rubber and chemical industry, oil drilling, oil refining oil and tar refining oil industry and national defense industry, machinery industry, wood processing and metallurgical industry. Medicine industry and city construction. It is also used in the manufacture of chemicals, paper, soap and detergent, rayon and cellophane.