Split-precipitation — An ecological alternative in the purification of crude sodium chloride brine

摘要

Due to the impurities of rock salt, crude sodium chloride brine requires purification. Only purified brine is capable to be used in modern evaporators or for the production of soda ash in a Solvay process. The brine purification process causes the onset of solid precipitates in the form of sludge. If this mud cannot be made use of in any way, it is washed into waters where it covers the ground and accumulates over years and decades. A novel brine purification process, Split-Precipitation, helps significantly reduce the amount of solids in the sludge (by about 30 wt%). The principal idea of Split-Precipitation is to initially precipitate Ca2+ and Mg2+ ions using soda ash and to work up the carbonates at the end with gypsum. This process does not require many additional expenses, but combines several ecological advantages.