A Study of Quartzites of the Koitashskoe Deposit for Their Applicability to the Production of Dinas Parts

Various samples of quartzite of the Koitashskoe deposit are studied for checking their applicability as a raw material for the production of dinas. In accordance with the degree of devolution, the refractoriness, the heat resistance, the water absorption, and the porosity, quartzites of the Koitashskoe deposit meet the requirements of the GOST 9854–81 standard and can be used for the production of dinas parts.     

Examination of the defective structure of tungsten powers by the electron-positron annihilation method

Powder Metallurgy and Metal Ceramics -     

Study of the material properties of micaceous vermiculite minerals of the Tebinbulak deposit

Studies are performed on the material composition of micaceous minerals of the vermiculite series in the Tebinbulak deposit. It is established that the micaceous materials studied consist of Mg-biotite, Mg-, Na-and Ca-hydrobiotite, and the chemical formula for the minerals is worked out. Results of the studies are of considerable practical value for developing the technology for preparing expanded vermiculite and preparing various materials based upon it. __________ Translated from Novye Ogneupory, No. 10, pp. 57–62, October 2007.     

Triangulation and Specific Features of the Phase Formation in Strontium Aluminosilicate Glass-Forming Systems

The SrAl₂Si₂O₈–Sr₂Al₂SiO₇–SrSiO₃ system obtained by the triangulation of the SrO–Al₂O₃–SiO₂ ternary system is studied. The ternary eutectic is determined at a temperature of 1310°C. In this region of the system, homogeneous glasses that correspond to the eutectic composition and garnet stoichiometry are synthesized at a temperature of 1350°C. It is established that the main phases formed upon crystallization of the glasses are strontium anorthite, strontium helenite, and strontium metasilicate.     

Processing of refractory materials using various magnesium sources derived from Zinelbulak talc-magnesite

Magnesia(MgO)is widely used in the production of refractory materials due to its high melting point,high thermal shock,and excellent slag resistance.The properties of refractory materials depend upon magnesia sources and processing parameters.In this work,three different magnesium sources,namely,magnesium hydroxide concentrate,magnesium carbonate concentrate,and intermediate flotation concentrate,were obtained from the Zinelbulak talc-magnesite,Uzbekistan,by causticization-hydration and flotation processes,respectively.A series of refractory materials were prepared on the basis of these magnesium sources,and their effects on physico-mechanical properties and microstructures were investigated as a function of sintering temperature,molding pressure,and the particle size of magnesium sources.The experimental results showed that a refractory material obtained from the magnesium hydroxide concentrate at 16000C for 4 h demonstrated favorable parameters due mainly to a higher degree of contact among fine particles.The results obtained from X-ray diffraction and optical microscopy confirmed the presence of periclase and forsterite as the predominant phases in refractory specimens.The prepared refractory materials meet the requirements of the State Standards(Nos.4689-94 and 14832-96)for magnesia and forsterite refractories,respectively.It is,therefore,suggested herein that the use of different magnesium sources derived from the Zinelbulak talc-magnesite will offer the potential to provide economic benefits in the refractory industry.     

Processing of refractory materials using various magnesium sources derived from Zinelbulak talc-magnesite

Magnesia(MgO) is widely used in the production of refractory materials due to its high melting point,high thermal shock,and excellent slag resistance.The properties of refractory materials depend upon magnesia sources and processing parameters.In this work,three different magnesium sources,namely,magnesium hydroxide concentrate,magnesium carbonate concentrate,and intermediate flotation concentrate,were obtained from the Zinelbulak talc-magnesite,Uzbekistan,by causticization-hydration and flotation processes...