Evaluating coking resources. 2. State standard GOST 25543-88 as a coding system for coal and coal mixtures in evaluating their technological properties

The codification of coal in State Standard 25543-88 is compared with the international codification of coal of medium and high rank. The ranking of coking coal on the basis of State Standard GOST 25543-88 is evaluated.     

Advantage of heat insulation made of materials with natural porosity

Various heat insulation materials produced at home and abroad are compared. The advantage of using natural nano-structured materials is substantiated. Translated from Novye Ogneupory, No. 7, pp. 41–44, July 2008.     

Tellurium clusters in channels of the porous silica ZSM-11

The distribution and structure of tellurium nanoclusters synthesized in crystal channels of the porous silica ZSM-11 are investigated using the maximum-entropy method and the Rietveld analysis. It is shown that the intercalated tellurium atoms are arranged in channels of the ZSM-11 zeolite not randomly but in the form of scraps of infinite chains similar to those observed in massive tellurium. The distances between the nearest neighbor tellurium atoms vary in the range 2.53(4)–2.70(3) ?. The clusters Te₄ are formed at the intersections of channels in the structure. These clusters have the form of distorted tetrahedra in which the tellurium atoms are separated by distances of 2.53(4) and 2.90(4) ?. Original Russian Text ? A.E. Lapshin, Yu.F. Shepelev, Yu.I. Smolin, E.A. Vasil’eva, 2008, published in Fizika i Khimiya Stekla.     

Study of medium-cement concrete based on mixed Chamotte-periclase chromite filler

The possibility is demonstrated of using an addition of periclase-chromite filler (PCF) prepared from PCF grade broken material articles in medium-cement concrete with chamotte filler. The effect of this addition on cement hardening duration, strength and heat resistance is considered. Translated from Novye Ogneupory, No. 8, pp. 42–46, August 2008.     

Software for computing dusty air flows in ventilation systems

Programs are presented for calculating dusty air flow in ventilation systems, which have been derived from the method of singular integral equations. They allow one to construct flow lines and determine the velocity pattern for the air in a closed rectangular region with outlet, flow, and extraction holes; a study is made on the dust particle behavior in the aerodynamic field in which there may be a rotating cylinder or pumping cylinder; determinations are made of the concentration and grain-size composition of the dust in the extraction hole; one can construct flow lines and single-particle paths in multicoupled regions of potential flows containing any number of rotating cylinders and cylinder pumps. Translated from Novye Ogneupory, No. 5, pp. 53–58, May, 2008.