The potential of using of alkaline earth bentonite clays of Ukraine in the production of iron ore pellets

Abstract

Objective: to analyze and determine the potential of alkaline earth bentonite clays of Ukraine for use as a binder in the production of iron ore pellets. Methods: performing rheological studies of bentonite clay samples and their chemical analysis, electron microscopic studies of samples. Results: the analysis of the chemical composition and requirements for the rheological characteristics of bentonite clays used in the production of iron ore pellets at metallurgical enterprises of Russia and Ukraine is carried out. The swelling indicators and water absorption of monoionic forms of bentonites of some deposits in water of different hardness are given. The quality of pellets with bentonites, that have a different exchange complex, during an industrial water of various hardness usage is examined. The analysis of the mineralogical and chemical composition, as well as the size and composition of the exchange complex of alkaline-earth bentonite clays of the Cherkassk deposit (Ukraine), which has the largest reserves of such clays in the CIS is carried out. It is shown that clays suitable for the production of pellets are located near the surface of the earth. A comparative analysis of the strength characteristics of pellets using bentonites with an alkaline and alkaline-earth exchange complex is presented. Scientific novelty: it was shown that despite the low swelling of alkaline-earth bentonites, the quality of pellets with these bentonites, in some cases, is slightly lower, and in certain conditions is not inferior to the quality of pellets with alkaline bentonites at the same flow rate. Practical significance: for real industrial conditions it is shown that the increase in water hardness leads to partial or complete (depending on the value of hardness) replacement of alkaline exchange complex with alkaline earth and conversion of alkaline bentonite clay into alkaline earth with corresponding rheological characteristics, deterioration of lumps and the need to increase the content of bentonite in the charge. In the case of increased hardness of water in the concentrate, it is economically feasible to use in the production of alkaline earth pellets bentonite clay, if it is cheaper than alkaline.