Abstract: When a bituminous emulsion is added to a water-containing sludge, the sludge is instantaneously separated into an aqueous layer and a solid layer. But, heavy metals other poisonous pollutants cannot be removed from the separated aqueous layer. In contrast, when a sulfur compound or colloidal sulfur is added to such sludge in combination with a bituminous emulsion, heavy metals and other poisonous pollutants are converted to water-insoluble or hardly soluble sulfur compounds and they are readily removed from the separated water layer. When an inorganic coagulant or organic polymeric coagulant is added in combination, the coagulating and solidifying effects can be further increased. Moreover, the heavy metals and other pollutants fixed in the solid layer are hardly dissolved out and therefore, the separated solid cakes can be used for reclaiming or as water shielding walls.

Abstract: A paving composition comprising asphalt and micro-granular coal which are uniformly combined integrally with each other without thermal decomposition of said coal and a method for producing a paving composition which comprises triturating a mixture of asphalt and coal at a temperature below the thermal decomposition point of the coal thereby to reduce the diameter of the resulting micro-granular coal to 1 to 100.mu. and, at the same time, to achieve the uniform integral combination of asphalt and coal. Thereby, there is provided a paving composition which is excellent in thermal stability, weather resistance, adhesive property, sticking strength, viscoelasticity and workability. Moreover, besides the main components, asphalt and coal, various modifying agents or additives may be further incorporated so that the properties of the paving composition can be further improved.