BACKGROUND At present, the volumes of use of electric arc furnace (EAF) dust are extremely insignificant. The volumes of their formation amount to thousands of tons per month. During storage, they have a negative impact on the environment. At the same time they are a material that has a valuable composition (oxides of iron, non‐ferrous metals, etc.) and is promising for recycling. However, the secondary use of zinc‐containing EAF dust in ferrous metallurgy leads to the accumulation of zinc in the lining of blast furnaces and frequent malfunctions. RESULTS It has been established that zinc oxide is mainly in the bound state in the composition of the franklinite phase (Zn,Mn,Fe)(Fe,Mn)2O4. The processes of solid‐phase reduction of EAF dust with the production of zinc concentrate and sponge iron, which are in demand as raw materials for non‐ferrous and ferrous metallurgy, have been studied. The optimal conditions for the reduction process were determined and the physicochemical characteristics, granulometric and phase composition of the initial materials, and reduction products were investigated. CONCLUSIONS It has been established that the use of a combination of reducing agents of different nature (coal coke and H2) during heat treatment at 1100 °C and cooling in a reducing medium (Ar/H2, 5 vol%) makes it possible to obtain sponge iron with impurities (the highest degree of iron metallization was 97.5%), and zinc oxide with a basic substance content of about 98.4 wt.%. © 2022 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

BACKGROUNDSelf‐propagating high‐temperature synthesis was used to create mesoporous CeO2 and MgO powders as well as nanocomposites based on them for efficient degradation of organic dyes.RESULTSIt has been investigated how magnesium oxide and cerium oxide interact to affect the crystal structure, morphology and microstructure of the materials produced. It was assumed that CeO2 forms on the surface of MgO while the material's developed surface is preserved. The values of the specific surface area and average pore diameter of the studied samples depend on the composition and vary in the ranges of 16–41 m2 g−1 and 11.919 nm, respectively.CONCLUSIONIt has been established that the sizes of CeO2 crystallites in the composition of nanocomposites change insignificantly and range from 6.5 to 7.4 nm. The photocatalytic activity of the studied samples is at least two times higher compared to analogs. The samples MgO–CeO2 (30 mol%) and MgO–CeO2 (50 mol%) showed the maximum photodegradation efficiency of acid telon blue and direct bright blue dyes at levels of 98.5% and 92.5%, respectively. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).

The process of modifying aqueous powder suspension materials (APS) based on solid epoxy film-forming agents with highly dispersed powders of magnesium oxide was studied: production by ChemPur (n-MgO – primary size of particles is 36 nm), and magnesium oxide synthesized by a template method from the concentrated bischofite solution (MgOlab – primary size of particles is 102.8 nm). It was shown that presence of active functional surface OHgroups in both samples of magnesium oxide leads to the formation of secondary structures: aggregates and agglomerates. The nature of the influence of the size of aggregates of MgO particles and the conditions of dispersion on the properties of protective coatings is established. The nature of the influence of particle size and dispersion conditions on the properties of protective coatings is established. Optimal properties of coatings based on APS, sedimentation and aggregative stability of suspensions are implemented only under the condition of effective mechanical dispersion in a bead mill, when the most intensive destruction of large aggregates of n-MgO up to 50–60 nm occurs. The distribution of nanoparticle agglomerates in APS at the micro level (700–800 nm) using the MgO-lab does not lead to a significant change in the properties of APS and coatings based on them.It is shown that the introduction of n-MgO into APS allows reduces the curing temperature of the coatings from 110 to 90–100 °С. It is caused by the increase in the density of cross-linking of the spatial structure of polymer. The strength of modified coatings upon impact and tension increases by 2 times in comparison with the base composition, which does not contain nanomodifier, during curing of coatings at100 °C. In comparison with the known water-borne epoxy paints and varnishes, APS compositions are one-pack, they are more technological in use, have a long lifetime (up to 12 months in comparison with the viability of known two-pack epoxies, 1-8 hours). Materials can be used in industry for the protection of metal products, both as primers and as independent coatings.

Currently, the volumes of use of dust from gas-cleaning devices (DGD) of electric steel furnaces are extremely insignificant, as they have an impact on the environment during storage, but at the same time, they represent the material that has a valuable composition (oxides of iron, non-ferrous metals, etc.) and is promising for recycling. However, the secondary use of zinc-containing DGD in ferrous metallurgy leads to the accumulation of zinc in the lining of blast furnaces and frequent malfunctions. It has been established that zinc oxide remains mainly in the bound state in the franklinite phase (Zn,Mn,Fe)(Fe,Mn)2O4. The processes of solid-phase reduction of dust from gas-cleaning devices of electric steel furnaces with the production of zinc concentrate and sponge iron, that are raw materials in demand for non-ferrous and ferrous metallurgy, are studied. The optimal conditions for the reduction process were determined, the physicochemical characteristics, granulometric and phase composition of the starting materials and reduction products were studied. It has been established, that the use of a combination of reducing agents of different nature (coal coke and H2) during heat treatment at 1100 °C and cooling in a reducing medium (Ar/H2) makes it possible to obtain sponge iron with a high degree of metallization - 97,5 %.

The process of forming epoxy powder compositions with the participation of highly dispersed magnesium oxide in the preparation of compositions by extrusion mixing of components in the melt is investigated. It is established that highly dispersed MgO particles participate in the polymerization process and act as additional crosslinking units of defective regions of the polymer network, which improves the functional properties of epoxy powder compositions. Coatings based on modified compositions are characterized by high physicomechanical properties at low temperature curing (130 °С) and can be used to form protective coatings on heat-sensitive products.