RU2795848C1 - Coal dust wetting agent - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: invention is used as one of the most important components of prophylactic agents against freezing and dusting of bulk cargo, as well as agents for irrigating sources of dust suppression during coal mining, loading and transportation. The agent for wetting coal dust includes the preparation of an aqueous solution of a mixture of substances, including 5-25 wt.% beet molasses, 0.5-5 wt.% starch syrup, 5-10 wt.% sodium lignosulfonate, 15-35 wt.% ethylene glycol or propylene glycol. The mixture includes 10-30 wt.% nonylphenyl ether of ethylene glycol or polyethylene glycol and water - the rest. The mixture is stirred for 10 minutes.

EFFECT: increasing the efficiency of suppression of fine coal dust by improving the wetting properties of the composition and reducing the likelihood of freezing and clumping of bulk materials.

1 cl, 1 tbl, 1 ex

Description

The invention relates to the mining industry and is used as one of the most important components of prophylactic agents against freezing and dusting of bulk cargo, as well as agents for irrigating sources of dust suppression during coal mining, loading and transportation.

Known composition for wetting coal dust based on surface-active substances (surfactants) and water. As surfactants, diethanolamides of synthetic fatty acids are used at a concentration of 0.05-0.20 wt.% in an aqueous solution. The disadvantage of this method is the limitation of its application, namely the unequal degree of wetting of various coals, especially their fine dusts. Closest to the invention is a composition for wetting coal dust, including surfactant, electrolyte and water. However, the known composition is not effective enough to wet fine coal dust.

Known wetting agent for the suppression of coal dust, containing the following components, wt.%: alkylbenzosulfonic acid 11.3-14.3; sodium hydroxide 6.0-9.05; neonol 14.0-17.9; ethyl alcohol 1.25-1.75; urea 1.3-1.7; calcium chloride 1.25-1.75; bischofite 1.25-1.75; fragrance 0.2-0.5 and water 50-53.5 (RF Patent No. 2495250 C1, priority date 23.04.2012, publication date 10.10.2013, author Glebov A.F., RU).

The disadvantages of the known wetting composition include its complexity and multicomponent nature, which complicate the process of its preparation, may have a negative impact on the quality of the deposited dust in terms of its further use, and individual components may be harmful to human health and adversely affect the environment.

Known foaming composition used in the known method of dust suppression, according to which the binding and coagulation of dust is carried out in an aerosol air stream, including air-filled water (98%) high expansion foams in the following ratio, wt.%: oleic acid 0.8-1.2 ; caustic soda 0.4-0.6; glycerin 0.2-0.4; water - the rest (RF Patent No. 2332572 C1, priority date 02.26.2007, publication date 08.27.2008, authors: Shuvalov Yu.V. et al., RU, prototype).

The disadvantages of the known technical solution are the short duration of the time interval in which the effectiveness of the foaming composition is maintained, as well as the low efficiency of dust suppression of dust that has settled earlier - dust aerogel, which, when swept up, becomes the main source of air pollution with dust.

EFFECT: increased efficiency of suppression of finely dispersed coal dust by improving the wetting properties of the composition and reducing the likelihood of freezing and clumping of bulk materials.

The improvement of wetting properties is achieved due to the adhesion of dispersed particles of coal dust (any dust), due to this, the weighting and deposition of larger particles stuck together.

This goal is achieved in that the composition for wetting coal dust, including surfactants, electrolyte, binders and water.

The component composition is presented in Table 1.

Table 1 No. p / p Component name Content, % 1 Beet molasses 5-25 2 Molasses starch 0.5-5 3 Sodium lignosulfonate 5-10 4 Ethylene (propylene) glycol 15-35 5 Nonoxylate (nonylphenyl ether of ethylene glycol or polyethylene glycol) 10-30 6 Water up to 100%

The sodium lignosulphate component is used in an aqueous solution where the NaOH concentration is 0.05 g/l. As studied in the article "Surfactant properties of sodium lingosulfate" (UDK 668.473:678.0:541.183, authors D.P. Savitskaya, K.V. Makarova, A.S. Makarov), the concentration is optimal for the surface tension of an aqueous solution. Sodium lignosulfonate reduces interfacial tension at the water-air-solid interface, thereby trapping hydrophobic fine particles. A content range of 5 to 10% is sufficient when mixed with other ingredients.

Beet molasses is used as a buffer solution. The presence of strong bases and weak acids in molasses gives it buffering properties. Mixtures consisting of a weak acid and its salt with a strong base, or a weak base with a salt of a strong acid, have the ability to counteract changes in the pH of a solution when some acid or base is added to it. Molasses creates a thin, durable hydrated layer, thereby causing less dusting of fine particles. A content range of 5 to 25% is sufficient to show buffering properties. Less than 5% is lost the effect of the application, more than 25% is not cost-effective, because. an increase in the concentration of molasses reduces the concentration of other components of the mixture, and therefore the effect of other components is reduced.

Starch molasses gives the viscosity of the mixture, which allows fine dust particles to stick together into larger ones, and, consequently, heavy and quickly deposited. The feature allows to increase the efficiency of wetting. Molasses, like molasses, creates a thin, durable hydrated layer, thereby causing less dusting of fine particles. A range of 0.5 to 5% is optimal. The use of a concentration below 0.5% makes the solution practically non-viscous. And the use of a concentration of more than 5% significantly increases the viscosity and makes it difficult to spray, which practically reduces the effectiveness of the solution.

Ethylene glycol is a dihydric alcohol used in the manufacture of antifreezes and coolants. Alcohols are classified as substances with surface-active properties. A concentration of 15 to 35% is optimal. The concentration below 15% in the composition of the mixture does not allow to achieve the desired cooling effect, and above 35% the cooling effect does not increase, but the mixture is not profitable.

Nonoxylate (nonylphenyl ethers) - is a mixture of nonionic surfactants, also needed to reduce interfacial tension. The optimal range is from 10 to 30%. Within these limits, the content in the mixture makes the mixture easy to spray, helps to increase the dispersion of the sprayed droplets.

The proposed active wetting agent is added to water and a concentration of an aqueous solution of 0.1-5.0% is obtained.

Water is added depending on the concentration of the remaining elements and the content of ethylene glycol to obtain a liquid solution, stirred for 10 minutes to obtain a well-dispersed composition. A mixing time of 10 minutes is sufficient to obtain a well-dispersed composition, which in turn improves the wetting properties of the entire mixture, in which the components are evenly mixed.

The properties of all components make it possible to obtain a slightly viscous, freezing-resistant substance, which, when dissolved in water, allows irrigating dusty areas and effectively settling dust particles, coarsening them. At the same time, without causing sticking, damage and clumping of goods.

In addition, it has been experimentally confirmed that in the given ratios, all components of the mixture successfully perform their functions to achieve a technical result. Violation of the concentration below the stated ranges reduces the effect and makes the mixture either very thick and difficult to spray, or reduces the properties of the mixture for long-term sticking of dust particles. An increase in the concentration of individual elements violates the concentration of other elements and makes the mixture either ineffective in achieving the desired functions, or unprofitable and very expensive.

Example.

The active wetting agent has been tested in the manufacture of prophylactic agents against freezing and dusting of bulk cargoes. The working concentration of the activating wetting agent is 0.2-0.6 wt.%. A prophylactic agent using an active wetting agent has the properties of enveloping fine particles and retaining a hydrated layer of a prophylactic agent on the surface of these particles. The tests carried out make it possible to evaluate the effectiveness of wetting within 1-5 minutes after the introduction of a prophylactic agent based on an active wetting agent, fine hydrophobic particles.

Claims (3)

Agent for wetting coal dust, including the preparation of an aqueous solution of a mixture of substances in the following ratio of components, wt.%: beet molasses 5-25 molasses starch 0.5-5 sodium lignosulfonate 5-10 ethylene glycol or propylene glycol 15-35 ethylene glycol nonylphenyl ether or polyethylene glycol 10-30 water rest, while stirring the mixture for 10 minutes.