Sludge conditioning after pipe-rolling mill aggressive sewage waters neutralization

Abstract

. Many sewage treatment facilities of metallurgical plants are physically obsolescent. Frequent practice is joint neutralization of spent pickling solutions (SPS) and rinsing waters (RW) by lime mortar followed by discharge of such “neutralized” aggressive sewage water in collectors of wastes. Therefore, implementation of modern equipment and technologies for cleaning of aggressive sewage water is an extremely actual task. The purpose of the work – to select a scientifically based type of flocculants and their optimal dozes for sludge, formed at the SPS and RW neutralization, processing. Results of the studies of flocculants processing of existing sewage treatment facilities (neutralization stations) sludge of one of pipe-producing plant of Ural quoted. Really formed sludge of two types were studied: the sludge after neutralization of pickling solutions and the sludge of rinsing water. In the course of the work, the effectiveness of application of high-molecular flocculants of cation, anion and non-ion types was estimated for conditioning of the sludge. As the criteria of the flocculants effectiveness the minimal time of capillary water suction from the processed by flocculants sludge, determined by special timer of capillary suction and chromatographic paper Whatman 17 Chr. As a result of the studies carried out, it was determined that for conditioning of a sludge of SPS neutralization, the non-ion flocculants Praestol 2500 (the doze 5 kg/t) was most effective. For a sludge of RW neutralization the anion flocculants Praestol 2540 (the doze 2 kg/t) was found to be most effective. After proposed flocculants, processing the sludge can be directed for concentration and mechanical dewatering. The conditioning of the sludge by flocculants will enable to increase the productivity of dewatering equipment.