Additive for carbonaceous solid-water slurry, method for production thereof, and carbonaceous solid-water slurry composition

摘要

An additive for a carbonaceous solid-water slurry which excels preeminently in the ability to disperse a finely powdered carbonaceous solid in water and, when used only in a small amount, permits production of a carbonaceous solid-water slurry which possesses high concentration, exhibits high fluidity, and precludes change of viscosity due to aging, a method for the production of the additive, and a slurry composition are provided. The additive to be used for high concentration of carbonaceous solid-water slurry comprises a specific water-soluble copolymer and contains a low molecular copolymer (a) having a weight weigh-average molecular weight in a range of from 1000 to 39000 and specific ratios of adsorption relative to a carbonaceous solid and a clayish mineral and a high molecular copolymer (b) having a weight weight-average molecular weight of not less than 40000 and specific ratios of adsorption relative to a carbonaceous solid and a clayish mineral at a weight ratio, (a)/(b), in the range of from 10/90 to 99/1, the met hod is for the production of the additive, and the slurry composition is produced by the incorporation of the additive.