Objective: to analyze and determine the influence of bentonite clays of different deposits and exchange ionic complexes on the metallurgical properties of iron ore pellets. Methods: performing rheological studies of bentonite clay samples and their chemical analysis, electron microscopic studies of samples. To assess the metallurgical characteristics of the pellets obtained, the moisture of the pellets, the compressive strength of the wet and dry pellets, the number of dumpings without destroying the wet pellets, and the temperature of the «shock» have been determined. Results: laboratory tests were conducted to determine the suitability of bentonite clays of different mineralogical composition and exchange ion complex for the production of pellets. Tests have shown that the impact resistance and compression resistance of raw pellets at a slightly increased specific consumption of bentonite Cherkasy alkaline-earth bentonite does not concede to the same properties of pellets with the use as a binder alkaline Saryugyhsky bentonite. It is demonstrated that to ensure good quality of raw pellets, an auspicious variety of clays of the Cherkasy deposit are clays of the IV layer, which are a natural mixture of alkaline-earth bentonite of the II layer and palygorskite (III layer). Tests of composite mixtures of clays IV with II and II with III layers showed that the quality of raw pellets with Cherkassky bentonite is slightly worse than with Sarygyuhsky, however, the absolute values of their indicators satisfy the industry requirements. Comparative tests of pelletizing of charges with different humidity and with the addition of 0.5% alkaline bentonite and a mixture of clays of the IV and II layers of the Cherkassky deposit have been carried out. It is shown that with increasing humidity in granules with both types of binders, the dynamic strength, porosity and temperature of the “impact” of granules increase with a minimum difference in the absolute values of indicators with different binders. To objectively confirm the possibility of using alkaline-earth bentonite of the Cherkassky deposit (II-III-IV layers) in the production of pellets, it is necessary to conduct comparative industrial tests at a pelletizing plant (for example, SevGOK), using a concentrate with the in-creased hardness of industrial water. Scientific novelty: the influence of alkaline bentonite replacement in charge for pellet production with alkaline earth, paligorskite clays and mixtures of their forms has been studied. The comparative influence of moisture content of raw pellets on their porosity and strength characteristics with alkaline and alkaline earth bentonites in the charge was studied. Practical significance: using the properties of raw, dry and calcined pellets as an example, the possibility of using less scarce and expensive local bentonite clays instead of expensive exported alkaline clays without impairing the production technology and characteristics of the pellets is shown.

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.