Abstract: The wet flow characteristic of water-insoluble solid particles such as coal is enhanced by forming on the surface of the solid particles a coating of a fluid having the property of lowering surface tension in aqueous solution, preferably a water solution of a substance from the group consisting of methyl and dimethyl naphthalene sulfonates and ethoxylated linear secondary alcohols, the substances being highly water soluble and the water solution having a low viscosity, a high flash point and low toxicity.

Abstract: Low temperature discharge of particulate material from a hopper or the like is facilitated by coating the hopper walls with a water solution of an inorganic freeze point depressant, the solution having a freezing point below about -20.degree. C. and being thickened by the addition thereto of a compatible thickening agent, whereby the substance can be readily applied to the wall and will remain in position on the wall. When the substance is to be used to coat steel or aluminum walls the pH of the substance is modified if necessary to prevent corrosion of the wall without adversely affecting the viscosity of the substance.

Abstract: The collection characteristics of particles entrained in a particle-laden gas for separation by the commonly used methods for removing particles from a gas stream are improved by injecting into the gas stream a conditioning agent comprising diammonium phosphate and urea. The conditioning agent can be added to the gas stream either at low temperatures or at high temperatures, in both cases giving rise to significant improvements in emission characteristics. The additive of the present invention has a very significant advantage over prior art additives of substantially equal emission improvement characteristics of greatly reducing or substantially eliminating buildup of hard-to-remove deposits.

Abstract: The collection characteristics of particles entrained in a particle-laden gas for collection by an electrostatic precipitator are improved by injecting finely divided sodium and ammonium phosphate salts into a particle-laden gas stream formed by the burning of coal. Sufficient additive is injected to provide 24-1200 grams per metric ton of coal burned to form the gas. After injection, the stream is directed through a heat exchange means and finally into the precipitator to collect the particles therein.

Abstract: The bulk density and throughput characteristics of coking coal are improved by treating the coal with a surfactant and a combination of fuel oil and alcohol or of solid lubricant and water, the surfactant being soluble in, and increasing the spreading coefficient of, fuel oil or water, as the case may be.

Abstract: The resistance of particulate material to clumping or solidification at below-freezing temperatures is improved by applying to the particles a coating of a polymer emulsion in water which drys to a water-insoluble film. A freeze-point-depressing substance is preferably combined with the emulsion in order to prevent the emulsion itself from freezing at the temperatures to which the particulate material is subjected. It is believed that said coating minimizes the strength of adhesion between the particles and any ice which may form between them and also minimizes the strength of such ice.

Abstract: The effectiveness of electrostatic precipitators, and particularly existing electrostatic precipitator installations, is enhanced by introducing into the gas stream in advance of the precipitator a spark-inhibiting additive, and then increasing the voltage applied to the precipitator over that which otherwise could be applied. The spark-inhibiting additive is preferably an ammonium salt introduced into the gas stream at a relatively low temperature and preferably in combination with the introduction into the gas stream at a relatively higher temperature of known conditioning additives from the group consisting of sodium bisulphate, ammonium bisulphate, ammonium sulphate and mixtures thereof.