Experimental Investigation On Membrane Separation Used In Recycling Baking Soda Mother Liquor

Compared with the synthesis, it is more competitive to product and process baking soda with trona as raw materials. While its baking soda mother liquor recycling, the alkali is extracted in the mother liquor, leading to salt accumulating. It affects recovery rate and utilization rate of trona,and makes the baking soda product quality declining. Especially for solution mining method, the mother liquor reinjection will cause pollution to the original trona. Furthermore,some useful basic ingredients with baking soda liquor drained, which can result in resource waste and environmental pollution. So It is required to separat salt from aking soda mother liquor.Nowadays the basic principle in salt separation is to use the different inorganic salt solubility with temperature change characteristics. Specifically the solubility of the sodium carbonate, sodium bicarbonate and sodium chloride under different temperature is different, and it could choose the optimal parameter separation according to saline liquid system phase diagram. Considering the factors such as economy of the process to establish and salt separation effect, this topic proposed separating baking soda mother liquor by using membrane separation technology, which is based on the selection of nanofiltration membrane for different valence ion permeability.This paper preliminarily studies on the feasibility of the Nanofiltration membrane separation technique to desalination and explores new salt separation technology. Experiments first for nanofiltration membrane separation methods, discusses how the different operating pressure, operating temperature and the running time as operating factors contribute to separation efficiency of nanofiltration membrane alkali, then select salinity has good separation performance that is more suitable for technologize of nanofiltration membrane. Next, the experiment of baking soda sodium salt separation is carried on, which comes to a conclusion of the various parameters in the process of nanofiltration technology change law by analyzing and summarizing experimental data. At the last, the following Experiments examine the salt containing saline liquid separation effect for nanofiltration process device on the actual production.Experimental results show that salinity separation device of using nanofiltration membrane process is feasible, for transmittance of sodium chloride and intercept rate of sodium carbonate are above80%, which basically meet the subject requirements. Specifically Koch membrane is superior in salt separation effect. And it also determines the optimal operating conditions of nanofiltration process, studies the change law of process parameters, which can be taken as reference to the next industrial design and operation.