Background
Compared with membrane electrolysis alkali production technology, ion membrane electrolysis alkali production has been recognized by the world as more advanced and economical sodium hydroxide production method, which is the development direction of current electrolysis alkali production technology. Therefore, ion membrane electrolysis alkali production technology has developed rapidly. This method has the characteristics of energy saving, high product quality, no environmental pollution, low operating costs, and significant economic benefits, and is widely used by caustic soda manufacturers around the world.
Caustic soda production by Ion membrane technology has several major parts: 1） Primary brine purification equipment; 2）Secondary brine purification; 3）Refined brine electrolysis; 4） Chlorine and hydrogen treatment. Primary brine purification sector is very important,since it can greatly effect the post steps on quality and running cost.
Saturated crude brine from dissolving bath goes into reaction tank, to be mixed with reagent NaOH, Na2CO3. After reaction,CaCO3 and Mg(OH)2 will be precipitated, then flows to buffer tank. Ceramic Membrane system will run at crossflow mode to remove all suspended solid and sediment. Because of the fine nano meter pore size and abrasive membrane layer, the permeated brine quality after CRBR membrane system can be very high and keep stable on long period operation, even the quality of feed crude brine specification is fluctuating badly.
Compared with polymeric filter process and clarifier process, there is much less pre-treatment for crude brine before going to CRBR system because of the advanced performance of ceramic membranes in nanometer size.The primary brine process by means of CRBR membrane technology can be One-step filtration. After CRBR membrane system, the SS and concentration of Ca+Mg can be controled at very low level.
Quality of Filtrated brine from CRBR membrane system:
Suspended Solid: ≤0.5mg/L
Ca2++Mg2+：≤0.5mg/L
Wide adaptability to all kind of raw salts: Sea salt, Lake salt ,Rock salt, Well salt
CRBR membrane technology have been widely and successfully applied for primary brine purification in many chloralkali plants in countries like China, India, Turkey, Russia,Mexico,USA,etc.
Process Diagram
Process Advantages
● A simplifed refining process with one step filtration
● High and stable quality of refined brine
● No use of flocculant agent
● Low operating cost
● No need of precoating process
● Wide adaptability to all raw salts
● Reliable and stable performance
● Long membrane worklife
● Benefit for post chelate resin and electrolyzer system
● Low labor and maintenance cost
● Compact design with small foot print
If you need more details about ceramic membrane process for CRBR & SRS technology in chloride alkali industry ,please do not hesitate to contact with us or send email to us. TANGENT is willing to communicate and share information with you on engineering process issues. We are looking forward to developing more market and more applications with your help, bring this new technology to end users, create more values and benefits for all parties.
