RU2453574C1 - Deicing composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: deicing composition contains the following (wt %): bischofite 51.2-57.6, alkali metal hydrophosphate 0.3-0.7, alkali and/or alkali-earth metal acetate 0.5-3.0, alkali metal carbonate 0.3-0.5 and talc 0.01-0.05, water - the balance. The solution has pH 6.5-8.5 and density 1240-1260 kg/m³.

EFFECT: deicing composition provides low icing temperature, has low corrosive activity and does not destroy road surfaces and building structures.

5 tbl, 3 ex

Description

The invention relates to substances designed to combat icy and snow on roads and pedestrian roads, with icing of industrial, transport and other structures. In addition, it can be used for transportation of freezing bulk goods, for thawing frozen soil, etc.

Anti-icing compositions based on alkali and alkaline earth metal chlorides are widely known, including based on a salt of magnesium chloride (MgCl ₂ ) with various inhibitory additives to reduce corrosion activity. For example, an anti-icing composition containing magnesium chloride (MgCl ₂ ) and / or carnallite (KCl, MgCl ₂ ), an inhibitory additive in the form of an acetate (or formate) of an alkali and / or alkaline earth metal (Na and / or Ca), and may also contain diethanolamine in addition to further reduce corrosion activity (RF patent No. 2141500, 1998) (1).

This drug, like all drugs based on alkali and alkaline earth metal chlorides, has high corrosion activity, and the introduction of diethanolamine into it with a slight decrease in corrosion activity significantly increases the cost, and most importantly, its harmful effect on wildlife and the environment as a whole. The use of this composition in dry form creates inconvenience in use due to its high hygroscopicity.

Known anti-icing compositions based on natural bischofite, which is based on hexahydroic magnesium chloride MgCl ₂ · 6H ₂ O (90-96 wt.%), Also contain other salts of alkali, alkaline earth and rare earth metals and more than fifty elements of the periodic table.

Closest to the proposed is an anti-icing composition, consisting of, wt.%:

- bischofite  20-40 superphosphate or disodium phosphate 0.6-2.8 - water rest

(RF patent No. 1249057, 1984) (2).

In this preparation, the use of bischofite as a low-freezing base reduces the destructive effect of the composition on road surfaces and the inhibitory effect on plants, and its corrosion activity decreases due to the phosphate additive.

The disadvantage of this composition is the insufficient icing temperature of the composition, respectively, a limited temperature range for use and a sufficiently high corrosion activity.

An object of the invention is to increase the efficiency of the composition by lowering the icing temperature, increasing the adhesion coefficient to improve road safety, reduce corrosion activity in relation to metals and increase its environmental safety.

The problem is solved in that in the anti-icing composition containing bischofite, a phosphate additive and water, it contains an alkali metal hydrogen phosphate as a phosphate additive and additionally contains an alkali and / or alkaline earth metal acetate, an alkali metal carbonate and talc at a pH of 6, 5-8.5 units and density 1240-1260 kg / m ³ in the following ratio of components, wt.%:

- bischofite 51.2-57.6 - alkaline acetate and / or alkaline earth metal 0.5-3.0 - alkali metal hydrogen phosphate 0.3-0.7 - alkali metal carbonate 0.3-0.5 - talc 0.01-0.05 - water rest

The technical result is achieved, first of all, by a significant increase in the amount of bischofite in the composition, which allowed to reduce the icing temperature to minus 51 ° C, i.e. to increase the efficiency of the composition and expand technical capabilities in temperature conditions below minus 10 ° C.

The presence in the acetate composition of an alkali and / or alkaline earth metal (e.g., Na, K, Ca, Mg) due to the hydrophilic-hydrophobic structure and mixed with bischofite contributes to a more effective destruction of the crystal structure of ice formations, which in turn increases the efficiency of the composition.

Alkaline metal phosphate (sodium or potassium) is an effective corrosion inhibitor in the composition and provides corrosion protection for metal structures. In this case, it is preferable to use potassium hydrogen phosphate, as environmentally more valuable for wildlife, especially in a mixture with bischofite.

Alkali metal carbonate (sodium or potassium) allows you to adjust the pH of the solution in a given range of 6.5-8.5 units, i.e. in the region of neutral values, which in turn reduces the corrosiveness of the composition and increases its environmental safety. In this case, the use of potassium carbonate is preferable (see above).

It is preferable to use potassium compounds, which has a beneficial effect on vegetation and wildlife.

Finely ground talcum powder is needed to increase traction and improve road safety.

The composition is prepared by mixing the components in the calculated volume of water in accordance with the recipe (table 1) to obtain a solution with a density of 1240-1260 kg / m ³ and a pH in the range of 6.5-8.5 units.

Table 1 shows the options for the proposed composition.

Table 1 Options for the proposed composition No. p / p Components Amount, wt.% BUT B AT The density of the composition, kg / m ³ 1240 1250 1260 one. Bischofite 51,2 54,4 57.6 2. Potassium Acetate (optional) 3.0 1.8 0.6 3. Potassium hydrogen phosphate (as an option) 0.3 0.5 0.7 four. Potassium carbonate (as an option) 0.3 0.4 0.5 5. Talc 0.01 0,03 0.05 5. Water Rest

Table 2 shows the main technical characteristics of options for composition A, B, C according to table 1.

table 2 Characteristic Compositions BUT B AT 1. Density, kg / m ³ 1240 1250 1260 2. Icing temperature, ° C -49 -fifty -51 4. Corrosion activity to carbon steel (st.3, 10, 20) at 20 ° C, mm / year 0.128 0.122 0.118 5. Viscosity, MPa · s. 3,1 3.2 3.3 6. Cohesion coefficient, units 0.428 0.425 0.422

The main indicator that determines the anti-icing qualities of the composition is its operating temperature range, i.e. the icing temperature when mixing the initial solution with melting ice and snow, resulting in the formation of an aqueous solution of lower density.

Table 3 shows the icing temperature of anti-icer solutions of various concentrations and, accordingly, densities.

Table 3 No. p / p Dilution with water (de-icer: water) Density, aqueous solution, kg / m ³ Actual icing temperature, ° C one Concentrate produced 1250 -51 2 3: 1 1190 -45 3 2: 1 1165 -36 four 1.5: 1 1150 -thirty 5 1: 1 1125 -22 6 1: 2 1085 -eleven 7 1: 3 1065 -7 8 1: 4 1050 -5 9 1: 5 1045 -four

As can be seen from table 3, the composition works effectively when diluted with water in a ratio of 1: 1 in temperature conditions to minus 22 ° C in a ratio of 1: 2 to minus 11 ° C, and with a noticeable dilution with water 1: 5 to minus 4 ° C.

Table 4 shows the technical characteristics of the working solutions of the defroster

Table 4 Characteristic Compositions one 2 3 four 5 1. Density, kg / m ³ 1100 1125 1150 1175 1190 2. Freezing temperature, ° C -13 -22 -thirty -40 -45 3. Viscosity, MPa · s. 1.4 1,6 1.8 2.0 2.2 4. Cohesion coefficient, units 0.452 0.448 0.452 0.448 0.438

Table 5 shows the results of experimental tests of the proposed composition, where its consumption rate was determined depending on the type of winter slippage per 1 m ^{2 of} road and ambient temperature in the presence of 1 mm of precipitation in terms of water (1 mm of atmospheric precipitation on an area of 1 m ² equal to 1 kg of sediment or 1 liter of water).

The proposed anti-icing composition provides a low icing temperature, has a low corrosion activity, does not adversely affect (in comparison with analogues) wildlife (vegetation and living organisms), does not destroy road surfaces and building structures.

According to the test results (Tables 3, 4, 5), it was found that the most effective and economical is the use of this composition at an air temperature of at least minus 20 ° C.

Claims (1)

An anti-icing composition containing bischofite, a phosphate additive and water, characterized in that it contains an alkali metal hydrogen phosphate as a phosphate additive and further comprises an alkali and / or alkaline earth metal acetate, an alkali metal carbonate and talc, at a solution pH in the range of 6.5 -8.5 units and density 1240-1260 kg / m ³ , with the following ratio of components, wt.%:
bischofite 51.2-57.6 alkali and / or alkaline earth metal acetate 0.5-3.0 alkali metal hydrogen phosphate 0.3-0.7 alkali metal carbonate 0.3-0.5 talc 0.01-0.05 water rest