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Abstract. Methods and results of experimental study of explosive and wetting characteristics of coal dust are presented. Modified evaluation method of explosive characteristics of coal dust allows estimating critical concentrations of suspended dust at variation of temperature of ionizing ignition source corresponding to beginning of flame propagation by means of approximation method. Method of measuring the contact angle of particles of coal powder is based on visualization of the drop placed on the pressed coal.

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Work is underway on investigation of dust formation character and the method of air pollution survey dust content reduction on a site chamotte preparation is offered.The considerable air dustiness is one of the adverse factors of industrial environment on manufacture of wall building materials. Dust emissions worsen ecological conditions of regions, cause premature wear of the industrial equipment, promote occurrence of occupational disease of the attendants. Is especially sharp there is a problem of collecting escaping with gases of fine dust. Having small density it dissipates and moves OR the large spaces by blasts. The anaiysis of air pollution survey on industrial objects ZAO "Mine Management" shown that the workshop N23 branch of chamotte preparation i s the most intensive source of atmosphere pohtion. Air dustiness researches along a technological line and on workplaces, both granulometric and mineralogical compositions of airbome dust and sunken dust are carried out for an estimation of sanitary-hygienic working conditions, and also the receptions of necessary nonproduction measures given for development, on air pollution survey reduction.The concentration of a dust in air was measures by a weight method with the help of AFA filters. The gaugings were carried out in a zone of workplaces and aIong a technological line at height 1.5 meter fiom ground with lee side along dust torch on distance 1 m fkom dust source. The equipment aspiration, irrigation and a material moistening before splitting were absent, and the crushing product humidity made on average 0.6 -0.8 %.For reliability of results air dustiness measurements in the same point was carried out not less than 5 times, and then the average measures of dust concentration was determined.As measurements results show air dust content on a chamotte preparation site is unequal in various places.The least air dustiness is registered nearby a rotary crusher and hammer crusher. The conducted researches have shown that a dust on primary splitting site characterizes the greatest size. The dispersion ability rises on the next technological stage and it reaches the maximum in a ready material distribution pface. The dust granulometric composition researches were executed by a microscopic method. The chamotte dust study has shown that particles basic mass have mainly an oval form with even outlines without a rough indent and a ledge. From the air dustiness analysis follows that practically all sizing plant manufacturing equipment becomes an atmosphere poIlution source, at absence primary dust source (crushers) dedusting. But the dust concentration in air exceeds considerably extreme allowable noms.Harmful impurity receipt character and intensity in an atmosphere are caused in the basic conducting works accepted technology. Two line splitting circuit is used by chamotte manufacture at a factoy (Fig. 1). Fig. I The grinding-sorting equipment processing line scheme1 -a brick charging bunker; 2 -a conveyor J%I; 3 -a rotary crusher C-634; 4 -a conveyor NE^; 6 -a fumace; ...