Drainless Technology for Processing Highly Moist Iron-Containing Sludge and Dust

A drainless energy-saving technology for processing highly moist iron-containing sludge from metallurgical production has been developed. The patterns of the combined process of chemical dewatering of highly moist iron-containing sludge with pulverized lime and dolomite wastes, hardening and caking by pressing in a single technological cycle at the developed experimental facility are investigated. In the course of laboratory studies, the temperature of the mass, rate of dehydration, chemical composition of the mixtures, appearance of the resulting briquettes, weight loss during caking, moisture content of the mixtures, and mechanical strength of the briquettes were monitored. New patterns have been established that have made it possible to develop an annealing-free method for producing iron-containing materials and self-healing briquettes. The essence of this method, which is one of the main provisions of scientific novelty, combines the processes of dehydration self-curing of the mixture with the process of forming by applying external pressure to the hardening mixture in molds to obtain a lumped material in the form of briquettes in a single technological cycle. The proposed technology does not require drying and firing, and a set of strength properties occurs as the material cools in the air during the day. A new energy-efficient and waste-free method for the production of iron-containing briquettes has been developed, combining the processes of chemical dehydration and condensation in one technological cycle. The proposed project and technology will make it possible to organize production for the processing of highly moist iron-containing sludge and the production of complex iron-containing material as a secondary metal-containing raw material for metallurgical plants for the production of steel and rolled metal. This technology will make it possible to fully utilize not only iron-containing sludge but also finely ground limestone and dolomite roasting waste (limestone and dolomite dust of dry gas purification) as dehydrating and binders, as well as screening coke and coal as reducing agents. The proposed technology also solves the problems of environmental pollution and the allocation of land for the storage of industrial waste.