Coal water slurry dispersant and preparation method thereof

Abstract

The invention discloses a coal water slurry dispersant and a preparation method thereof. The preparation method comprises the following steps: (1) dissolving sodium sulfite in water, adding acetone, reacting for 20-40 minutes at 30-40 DEG C, heating to 45-55 DEG C, adding formaldehyde, and reacting for 20-40 minutes at 80-100 DEG C to obtain red liquid; (2) performing reduced pressure distillation on the red liquid, adding p-methylbenzene sulfonic acid and acrylic acid, and reacting for 4-8 hours at 80-100 DEG C to obtain a mixed solution; (3) mixing the mixed solution with acrylamide and potassium persulfate, and reacting for 2.5-4 hours at 80-100 DEG C to obtain a reaction solution; and (4) after the reaction solution is cooled, adjusting the pH value to 6.5-7.5, and centrifuging, depositing and drying to obtain the coal water slurry dispersant. The coal water slurry dispersant has better binding capacity with particles and can achieve a better dispersion viscosity reduction effect, and the structure of the coal water slurry dispersant has better matching property with that of a type of coal.

Description

technical field [0001] The invention relates to the technical field of environmental protection energy, in particular to a coal water slurry dispersant and a preparation method thereof. Background technique [0002] Coal slime is the main by-product of the coal washing process. It is a sticky substance composed of fine coal powder, minerals and water. Its main characteristics are small particle size, developed pores, high water content, high ash content and low calorific value. In 2010, my country's coal output reached 3.24 billion tons, the raw coal selection capacity was 1.75 billion tons per year, and the washing rate reached 50.9%. With the deepening of coal mining mechanization and the increase of the proportion of raw coal washing, the output of coal slime will further increase. Due to the improvement of coal preparation technology, the calorific value of coal slime produced is low, and because of the addition of medium powder in the flotation process, the civil use v...

AI Technical Summary

Problems solved by technology

[0005] Anionic dispersant: (1) Naphthalene sulfonate polycondensate: This type of dispersant is a widely used product in the coal-water slurry industry. Poor performance, after 24 hours of storage, it will produce hard precipitate and high water absorption rate; (2) Lignosulfonate: a coal water slurry dispersant mainly prepared from wood pulp, the advantages are: good stability, less water precipitation , and the raw materials are abundant and cheap. The disadvantages are: high viscosity, rough flow pattern, and need to be used in combination with other dispersants; (3) Humic acid series: this kind of dispersant is extracted from low-rank coal, and its dispersant performance is low. It is better than lignosulfonate, and it is easy to form hard precipitates. However, the slurry has poor stability and is sensitive to metal ions. Therefore, it has higher requirements for pulping water quality; (4) Polyolefin system: Polyolefin researched and developed by Japan Lion Company Sodium styrene sulfonate (PSS) is the representative of this type of dispersant, and its advantages are: less dosage, better pulping and stability than traditional dispersants, but very expensive; (5) polycarboxylic acid series: this Dispersants are usually formed by graft copolymerization of 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. It is then grafted and copolymerized with unsaturated carboxylic acid monomer acrylic acid, styrene sulfonate and other monomers. It has dual functions of dispersing and stabilizing coal water slurry. However, the price of this dispersant is relatively high

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

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