An additive for an aqueous coal - water sludge, a method for its production and aqueous coal - water atomized slurry concentration has

摘要

PURPOSE: To obtain the subject additive, containing a specific copolymer mixture, good in dispersibility and capable of providing a highly fluid and high-concentration carbonaceous solid-water slurry without changing the viscosity with time by adding a small amount thereof. ;CONSTITUTION: This additive contains (A) a low-molecular weight copolymer, having 1000-39000 weight-average molecular weight 5-40% surface coverage for a carbonaceous solid, etc., and a high-molecular weight copolymer, having ≥40000 weight-average molecular weight and ≥50% surface coverage described above, etc., and selected from water-soluble copolymers prepared by copolymerizing (A) a nonionic monomer of formula I [R¹ is CH₂, CO, etc.; A¹ to A³ are each H or CH₃; A¹ and A² are each H, COOX (X is H, an alkali metal, etc.), etc., (with the proviso that A¹ and A² are not simultaneously COOX); A³ is H, CH₂COOX, etc., when R¹ is CO or CH₂CO; A¹ and A² are each H or CH₃; R² is a 2-4C alkylene when A³ is COOX or CH₂COOX; (n) is 1-100; R³ is a 1-30C alkyl, alkenyl, etc.] with (B) an anionic monomer of formula II (R⁷ is H or CH₃; Z is a 1-4C alkylene; Y is X] such as a sulfo-alkyl (meth)- acrylate-based monomer.;COPYRIGHT: (C)1996,JPO