Yu. A. Dmitrienko

Advanced periclaselime powders for converter refractories

Kombinat Magnezit JSC has developed a process for manufacturing densely sintered large-grain periclase-lime powders that are resistant to hydration due to formation of enclosing films on the surface of the grains. A performance test of pitch-impregnated periclase-lime converter refractories at the Krivorozhstal’ Works has shown their advantages over dolomite-periclase refractories. The service life of a converter lining produced from the test powders was increased from 690 to 946 heats.

Improving lining resistance using high-magnesia fluxes in the converter steelmaking process

Tests carried out at the Severstal Joint-Stock Co. and Magnitogorskii Iron-and-Steel Works JSC showed that a lime-magnesia flux containing 30 – 35% MgO used in the converter steelmaking process produced a favorable effect on the refractory lining resistance. Compositions for high-magnesia granules (50 – 65% MgO) were developed, their properties characterized, and the rate of solution in the slag melt was determined. Using these granules in the converter process makes it possible to increase the service life of periclase-carbon refractories for converter linings.

A STUDY OF MAGNESITES OF PROVENANCE FROM THE GOLUBOE DEPOSIT (KRASNOYARSKII KRAI) AND THEIR LABORATORY TESTS FOR TECHNOLOGICAL APPLICATIONS AT THE KOMBINAT MAGNEZIT JOINT-STOCK CO.

Results of a preliminary study of the composition and properties of magnesites of provenance from the Goluboe deposit (Krasnoyarskii Krai, Russia) are reported. All magnesites, irrespective of their varietal, structural, and textural features, can be considered as acceptable raw materials. The concentration of impurities and inclusions in a high-quality magnesite does not exceed 1.5%, whereas in low-quality magnesites (2nd grade) they are within 3 – 8% of the total mineral composition. The heat-assisted beneficiation or calcination of raw magnesite yields a material with 98% MgO and a CaO-to-SiO2 ratio greater than 3, which provides means for producing high-quality periclase powders. Tests conducted under industrial conditions show that using technologies of fine grinding, pelletizing, and calcination at 2100°C makes it possible to prepare dense periclase clinker. Calcination of lumpy magnesite at still higher temperatures is not an efficient technique for dense periclase powders. Clinker technology is shown to be the best way towards obtaining periclase and periclase-containing powders using raw magnesite from the Goluboe deposit.

Electroseparation of sintered periclase powders

A laboratory separator and an industrial prototype developed by the Magnezit Integrated Works in cooperation with the Kola Branch of the Mekhanobr Institute for electroseparation of magnesite ores with an elevated content of dolomite and dolomitized magnesite are described.

Resource-saving technology for producing periclase powders with 92-95% MgO

A brief characterization of magnesite of the Satkinskoe Deposit and a technology for the production of periclase powders using two-stage firing of the raw material are presented. The quality of the fired product and the technical and economic parameters of the production of powders for basic refractories are described. Results on extraction of MgO into the fired products and an elemental analysis of caustic magnesite are presented. A possibility of two-stage firing in industrial conditions of reduced waste gases and quote of raw material consumption in the production process.

Properties for obtaining magnesia products from the Zabakal'sk group of magnesites

ConclusionsAn all-round investigation of the properties of refractories made from Zabaikalsk magnesites showed that they can be widely used in very diverse areas of metallurgy, engineering, medicine, perfume production, and other industries.

Investigation of refractories based on hollow periclase-containing granules

ConclusionsThe investigation into the possibility of obtaining periclase-spinel refractories of the PShPKh type based on fused materials and hollow KhGSh granules obtained on the “Plazmatron” equipment, showed unsatisfactory sintering of the granules with finely milled bond and, as a result, poor factors for compressed strength and refractoriness- under-load.In order to improve the production technology for refractories based on hollow KhGSh it would be of interest to activate the surface of the granules with various mineralizers and to choose finely milled bond.