Polycarboxylate water-coal-slurry dispersing agent and preparation method thereof

Abstract

The invention provides a polycarboxylate water-coal-slurry dispersing agent and a preparation method thereof, the general formula of the dispersing agent is that M is hydrogen or sodium or potassium or amino group; R1 is that n is 9-107; R2 is hydrogen, phenyl group or C1-C4 alkyl group; R3 represents hydrogen, C1-C4 alkyl group, C2-C4 hydroxyl alkyl group, C1-C4 alkoxy, phenyl or aromatic substituent group substituted by halogen, alkoxy and alkyl group. The preparation method is as follows: firstly, evenly stirring polyethylene glycol and polymerization inhibitor, then adding itaconic acid and catalyzer in sequence; preserving heat for 5 hours at the temperature of 90 DEG C to obtain an intermediate product; taking deionized water, sulphonate,intermediate product I and sodium hydrogensulfite, stirring while heating, adding aqueous solution of methacrylic acid and the aqueous solution of persulfate at the temperature of 75 DEG C, then preserving and reacting for 3 hours and cooling; and finally, adjusting the pH value to obtain polymer solution of the polycarboxylate water-coal-slurry dispersing agent, and the dispersing agent of the invention has good stability and low cost.

Description

【Technical field】 [0001] The invention relates to a coal-water slurry dispersant and a preparation method thereof, in particular to a polycarboxylate coal-water slurry dispersant and a preparation method thereof. 【Background technique】 [0002] Coal Water Slurry (CWS for short) is a new type of coal-based liquid fuel, prepared from 60-70% coal, 30-40% water and a small amount (about 0.2-1.0% of coal) of chemical additives The resulting solid and liquid two-phase coarse dispersion system. Low viscosity, high concentration, good fluidity and stability are the most important properties of CWS. However, coal is a lipophilic substance, and coal-water slurry basically belongs to a coarse particle suspension system. Even if it is an easy-to-slurry coal with a particle size distribution with a high accumulation rate, the slurry-forming property is often poor when there is no dispersant, and it is often placed for 12~ After 24 hours, the slurry will produce hard deposits, which ser...

AI Technical Summary

Problems solved by technology

It is characterized by pulping property, strong viscosity-reducing effect, and good pulp flow pattern, but poor stability. It will produce hard precipitate after 24 hours of storage and has high water absorption rate; (2) Lignosulfonate: mainly produced by wood pulp The prepared coal-water slurry dispersant has the advantages of good stability, less water separation, abundant raw materials, and low price. The disadvantages are: high viscosity, rough flow pattern, and needs to be used in combination with other dispersants; (3 ) Humic acid system: this kind of dispersant is extracted from low-rank coal, and its dispersion performance is better than that of lignosulfonate, and it is easy to form hard precipitates. However, the slurry has poor stability and is sensitive to metal ions. High water quality requirements; (4) Polyolefin series: Polystyrene sulfonate sodium (PSS) researched and developed by Lion Company of Japan is a representative of this type of dispersant. The advantages are: less dosage, excellent pulping and stability Compared with traditional dispersants, but the price is very expensive; (5) Polycarboxylic acid series: This type of dispersant is commonly grafted and copolymerized with unsaturated carboxylic acid monomers such as (meth)acrylic acid, maleate and other monomers. For example, acrylic acid and polyethylene glycol are used as raw materials to obtain polyethylene glycol monoester acrylic acid, which is then grafted and copolymerized with unsaturated carboxylic acid monomer acrylic acid, styrene sulfonate and other monomers. Dual function of dispersing and stabilizing, however, the price of this dispersant is higher

However, the cationic charges introduced after the coal particles of the coal water slurry contact with the zwitterionic dispersant lead to a significant decrease in Zeta potential, the repulsion between coal particles is weakened, and the coal water slurry system shows a tendency to agglomerate. Therefore, macroscopically, it shows poor dispersion retention it is good

Images