Utilization of distiller waste from ammonia-soda processing

摘要

The purpose of the research was to examine the utilization of basic waste of soda ash industry: distiller waste. The aim of the process described is to obtain calcium sulphate in the form of gypsum by means of calcium ions contained in distiller waste liquid. Another raw material is sludge, a suspension which is created during the process of brine evaporation in the salt processing industry. The process of calcium sulphate precipitation is based on calcium ions contained in distiller waste liquid and sulphate ions contained in sludges. CaCl_2 + Na_2SO_4 + 2H_2O→CaSO_4·2H_2O↓ + 2NaCl (1) Results of research have shown that the production of gypsum based on soda ash waste materials is possible. The new products achieve the standards necessary for production of building-quality gypsum. The additional advantage of the described method is obtaining not only gypsum sediment, but also sodium chloride solution (semi-brine). Soda ash factories may also benefit from the introduction of the technology (sale of gypsum, sale of semi-brine, release from environment pollution fees).