Utilisation of synthetic soda-ash industry by-products

A method of soda-ash industry waste utilisation was analysed in this study. Two waste streams, distiller waste and sludge, were considered. The method described is based on calcium sulphate precipitation. The aims of this study were to find the optimal precipitation parameters and to perform simple economic analysis of the process. Except for calculating the direct (running) costs, the authors applied a simple method for environmental cost estimation. The optimal precipitation conditions were obtained by using the simplex optimisation method. Based on optimal conditions of calcium sulphate precipitation, the material balance was calculated. The provided economic analysis takes into account both the investment costs and the running costs. For the Polish case study, this technology can generate 135,000[euro] profit per year. The overall effect (direct plus environmental) is estimated to be 363,000[euro] per year.