SU1710777A1 - Method of consolidation of dusty surface - Google Patents

Abstract

This invention relates to the surface treatment of a layer of material with a bonding coating, and may be. used in construction materials, in the metallurgical, coal, chemical and other industries of the national economy, in particular for bonding the dust separation layer when transporting bulk materials in open railway platforms, barges, cars on conveyor belts and etc. The goal is to increase the fixing efficiency and simplify the method. To do this, the surface of the bulk material is treated with a dust-containing compound containing sulphite-alcohol bard, water-soluble salts of styrene-maleic acid copolymer and water, to form a protective layer with a thickness of 10-20 mm. The dust-binding compound contains, in wt%, 1 sulfite alcohol bard 5–20; water-soluble salts of a copolymer of styrene and maleic acid 1.5-5.0; water the rest. 1 tab.

Description

The invention relates to the field of surface treatment of a layer with a bonding coating and can be used in the building materials industry, in the metallurgical, coal, chemical and other sectors of the national economy, in particular, to bond the dust release layer in the building materials industry during transport. bulk materials in open railway platforms, barges, cars, on conveyor belts, etc.

In open bulk shipments, the top surface is last treated with a binder for

elimination of dust formation and blowing of loose materials during transportation.

A known composition for the suppression of pressure, which is an aqueous solution of organic substances and inorganic acid salts.

The composition contains sulphite-yeast mash and vegetable oil stock as organic substances in the living substance, and sodium nitrite as the salt of inorganic acid.

The disadvantages of this composition are the low adhesion strength of the particles, the multicomponent composition of the binder, and the use of soap stock as one of the components of the food product.

vegetable oil, which is economically impractical.

The closest in technical essence to the present invention is a method of fixing a dusty surface, including treating the surface first with a solution of a surfactant, an alkylsulfoethoxydate, and then a dust-binding compound containing polyacrylamide (PAA), sulfite-alcohol bard (PRB) and water at a ratio component, wt.%: PAA 0,2-0,5; PRS 5,010, 0; water the rest.

The disadvantage of this method is the necessity of treating the surfactant surface with an aqueous solution of alkyl sulphoethoxylate, and then applying the binder compound. In addition, the low adhesion strength of the particles of the surface layer is caused by the weak binding capacity of the PAA polymer, the effectiveness of the functional groups of which is manifested in an alkaline medium. While PRS are mainly calcium lignosulphonates, aqueous solutions of which give an acidic medium (pH 4-5). Therefore, the full binder action of the polymer does not appear. To increase the strength of the coating, it is proposed in the well-known solution to pretreat the surface of the bulk material with an aqueous solution of alkyl sulfo-ethoxylate and to process the compound 2-3 times in 1-2 hours, which accordingly complicates the process.

The aim of the invention is to increase the strength of the coating and simplify the method of its application to the dusting surface.

The surface of the bulk material is treated to a crust thickness of 10-20 mm with a binder compound containing PRS, water-soluble styrene-maleic acid copolymer salts and water in the following ratio, wt.%:

PRS5-20

Water soluble

salts of copolymer styrene and maleic

acids1.5-5.0

Water the rest.

A comparative analysis with the known one allows us to conclude that the proposed method differs from the known one in that the surface of the bulk material is treated with a dust-binding compound, which, in addition to the PRS, contains water-soluble salts of styrene-maleic acid copolymer, to form a protective

a layer 10-20 mm thick, and the composition of the dust-binding compound differs from the known one, as follows: May. %: PRS5-20

Water soluble

salts of styrene and maleic copolymer

acids 1,5-5,0,

WaterEverything

0 Analysis of the known dust-binding compound compositions used to treat the top layer of bulk material and to obtain a fixing layer on the last layer in order to prevent dust formation, shows that some of the substances introduced are known, for example, PRS and water, but their use in these dust-binding compounds in combination with other components does not provide

For compositions, such properties that they show in the proposed solutions, namely, a significant increase in the strength of the surface layer of the material and the exclusion of dust formation and blowing loose

5 materials in the open transport of the latter.

The use of small additives of water-soluble salts of a copolymer of styrene and maleic acid eliminates the need to treat the surface layer of the drying materials with a solution of alkyl sulphoethoxylate. The latter is explained by the presence in the polymer of the hydrophobic component of styrene (-CH-CH2-) and hydrophilic

 С-сн-сн-) k /. pg, l d maleic acid.

MeEP COOMe

where Me Na, NH4 k.

The presence in the binder composition of a polymer containing hydrophobic and hydrophilic parts, allows to treat polymineral dispersed substances having different surface filaments. As a result, the number of

5 contacts of the polymer with the dispersed substance and the strength of the protective layer as a whole. Moreover, the latter is achieved when the content of the polymer in the compound is 1.5–5.0%. It has been established that the surface treatment of the dusty dispersed material must be carried out before a protective layer with a thickness of 10–20 mm is formed. The latter is achieved by varying the consumption of the binder compound. With a smaller thickness, the resulting coating is fragile and cracks under dynamic loads. Increasing the thickness of the crust above 20 mm leads to an increase in the consumption of components, which is not economically feasible,

Thus, the use of water-soluble styrene-maleic acid copolymer salts as a polymer imparts new properties to the dust-binding compound, which eliminates the pretreatment of the dusting surface with surfactant solution, as well as the repeated treatment of the surface of the dispersed material with a dust-binding compound. Surface treatment of the bulk material with the developed composition to form a crust 10–20 mm thick results in a more durable coating.

The PRS is a waste product from wood processing at pulp and paper mills and is produced in liquid form with a dry matter content of 47-52% or powder. The mass fraction of the reducing substances to the mass of dry substances is 9-12%, the pH of a 20% aqueous solution is 4.30-4.01, the viscosity on the VZ-1 viscometer is 302 s, the density is 1.25 g / cm. Studies show that the content of the PRS in the compound should be 520%, with a content of the proposed polymer of 1.5-5.0%. .

The polymer component of the composition is obtained by neutralizing a styrene-maleic anhydride copolymer with an aqueous alkali solution. The initial copolymer is obtained by radical copolymerization of styrene with maleic anhydride in an organic solvent medium, the characteristic viscosity of the obtained copolymer G} is 0.5-0.6. The structure of the salt of a copolymer of styrene and maleic acid can be represented as follows:

t-CHj-CH-CH - CH-CgH COOMe COOMe

Thus, each component of the dust-binding compound performs certain functions.

PRI me R. Fine powdered apatite is used as a dusting material. The binder compound is prepared by mixing the components, which are then applied to the surface of the bulk material with a sprinkler. The condition of the coating is evaluated both in the wet state and after drying under normal room conditions. The strength of the coating is checked by a jet of air at a speed of 10-15 m / s, and the surface condition after

aerodynamic tests visually, noting the presence of cracks and damage in it. Wetting the surface of the bulk material assessed visually. Thickness

The crusts are determined using calipers to reach certain sizes by varying the flow rate of the binder compound. The test results are presented in the table.

As can be seen from the table, the proposed method for fixing the surface of a dispersed material with compositions 2-4 increases the effectiveness of fixing the surface of the bulk material by forming

more durable protective peel that prevents dust from blowing up by the wind.

The use of the composition 6 leads to the formation of a thin protective film in view of

increased viscosity of the binder composition. While the content of the components is below optimal (composition 5) a thick crust is formed, which, however, has low strength, cracks and collapses during dynamic testing. The latter is due to the low content of binding components.

The use of the invention in comparison with the known one allows to improve the ecological situation on the territory of transportation of bulk materials, to exclude unnecessary losses of material during its transportation by excluding dust emissions into the atmosphere,

Claims (1)

improve economic performance by reducing the loss of dispersed materials. Claims method of fixing a dusty surface, including surface treatment bulk material with a dust-binding compound containing sulphite-alcohol bard, polymer and water, characterized in that, in order to increase the strength of the coating and simplify the process, The surface treatment is carried out before the formation of a protective layer with a thickness of 10–20 mm by a dust-removing compound containing water-soluble styrene-maleic acid copolymer salts as a polymer, in the following ratio of components: May: Sulfite-alcohol bard5-20 Water soluble salt copolymer sti-. rola and maleic acid 1,5-5,0 WaterEverything Rest 1 0.35 7.5 123.2 Else 15 1.5 Remaining 10 Cracks, destruction, blowing up dust The crust is not destroyed, there is no dusting up No damage, minor cracks, no uplifting Famous