The results of experiments on manganese pellets based on beneficiated manganese-containing sludge and the melting of ferromanganese alloy with their use are presented. Via beneficiating manganese-containing sludge (16.32% Mn), a concentrate with a manganese content of 35.2% was obtained. The composition of the charge used to prepare manganese pellets is proposed, and the conditions affecting their strength are determined. It was established that manganese is present in the composition of calcined pellets in the form of jacobsite MnFe₂O₄ and hausmannite Mn₃O₄. The formation of a phase of ferrobustamite (Ca_0.79Fe_0.21)SiO₃, a ferrosilico-calcium binder that helps increase the strength of pellets, was found. Ferromanganese alloy was obtained as a result of the melting of calcined manganese pellets in a high-temperature Tamman-type unit. The Fe-Mn-Si alloy corresponds to the DIN 17 564 as-grade FeMn70Si in terms of manganese (63.76%) and silicon (17.21%) contents. The content of limiting impurity elements—carbon and phosphorus—in ferromanganese alloy is within acceptable limits. The structure of Fe-Mn-Si alloy and slag formed during their smelting process were studied.

The review covers existing modern technologies and researches on applying diatomaceous minerals as silicate additives to building materials. Specialists of industrially developed countries actively work in this direction and there are some of the works on the stage of implementation now. The article also describes researches of the authors on synthesis of calcium silicate and hydrated forms of ferro-calcium silicates using different kinds of Kazakhstani diatomaceous minerals from Zhalpak deposit (Aktobe region) as main siliceous component. Main topological and physical-and-mechanical characteristics of natural diatomaceous minerals were studied. It was found out that using thermally activated diatomite mixed with a plasticizing agent enlarges strength under compression and raises the brand of building materials while lowering water absorption and specific weight. It was observed that use of thermally activated highly ferriferous diatomite (20-30 % of Fe2O3) increases the strength of building materials dramatically. X-ray phase analysis of the samples of cubes from obtained composites exposed to semi-dry pressing with thermally activated ferrous diatomite followed by steam tempering showed that there were Ca(Fe, Mg)Si2 and FeAl2SiO5(OH)2 in their composition in the amount up to 1 mas. %.The technical characteristics of cubes of composition obtained with the use of thermally activated diatomite, in particular its highly ferriferrous forms, are completely meet requirements of inter-state standards GOST 379–95 to siliceous stones and bricks and sometimes overcome this norms. In future, the technology for obtaining the synthesized materials can become a base to organize new and to improve the existing industries producing dry building mixtures and strong silicate bricks in Kazakhstan.

Hexavalent chromium Cr (VI) compounds present in ilmenite concentrate not only pose significant environmental hazards due to their toxicity but also complicate further processing, interfering with technological operations in industrial production. The high chromium content in ilmenite concentrates hinders their conversion into titanium-containing slag, necessitating the removal of chromium ions to permissible residual levels to produce titanium dioxide. In this study, various sorbents were investigated for the removal of chromate ions from the industrial effluents generated during ilmenite concentrate processing. The sorbents examined included natural and modified diatomite, activated carbon, taurite (shungite), and the ion-exchange resin Lewatit M500. The structures of both natural and modified diatomite were analyzed using scanning electron microscopy (SEM). It was determined that natural diatomite samples consist of diatom frustules of various shapes and their fragments, with structural element sizes ranging from submicron dimensions to 50 µm. A mathematical analysis of the sorption data for hexavalent chromium ion removal from solutions was performed. The results demonstrated high sorption efficiencies for Lewatit M500 (98.34%) and diatomite modified with iron compounds (98.95%). The findings suggest that diatomite is a promising sorbent for chromate ion removal from wastewater due to its availability and potential for chemical modification.

Substandard ores and technogenic wastes can be considered as an additional source of raw materials due to the limited resources of mineral raw materials with a high content of manganese. The article presents an overview of studies intended to process low-quality manganese-containing raw materials by beneficiation of them with the production of manganese concentrates, agglomeration of manganese fines with the formation of pellets, and smelting of agglomerates into ferromanganese alloys. The main raw material sources of manganese are characterized. Manganese ores are divided into three main types - oxide, siliceous and carbonate ones. The method to beneficiate the raw material is chosen depending on the raw material type. The application areas of manganese alloys are described - they are used in the form of ferromanganese and ferrosilicomanganese to produce steel and cast iron in ferrous metallurgy; as an alloying metal in bronze, brass, most aluminum and magnesium alloys in non-ferrous metallurgy. The beneficiation processes for low-quality manganese-containing raw materials - sub-standard ores and technogenic wastes are considered. A promising direction in the beneficiation of ferromanganese ores is magnetic separation. The extraction of manganese from technogenic sources - ore fines, sludge tailings of processing plants is of great ecological and practical importance. Methods for agglomeration of manganese fines with the production of pellets, briquettes, the influence of the content of acidic and basic oxides, the composition of binder materials on the properties of pellets are described. Data on the influence of various factors on the manganese ferroalloy smelting process, the reduction of manganese ore pellets, and the phase transformations occurring during the process are specified.