SU910678A1 - Composition for producing foamed plastic - Google Patents

Description

(S) COMPOSITION FOR GETTING FOAM

The invention relates to compositions for the preparation of foams based on urea-formaldehyde resins and can be used in potash plants to protect the salt dumps surface from dissolution by precipitation, for example, as an equalizing (intermediate) layer of the combined coating. li Salt dumps are the accumulation of waste rock, which is formed as a result of the processing of sylvinite ore at the processing plants of the potash industry. By chemical composition, waste dumps for 88-92% consist of sodium chloride. The remaining part contains H (ebols), potassium chloride, magnesium chloride, calcium sulfate and insoluble (clay) residue - up to 5%. Salt dumps have a shape approaching the shape of a truncated cone with a slope angle of 20 "O and height up to 50 K and more. The hydro-isolation of this type of waste is an important problem, since its dissolution leads to salinization of groundwater, surface water bodies and nearby land. At present, due to the increasing amount of waste entering the dumps and increasing requirements for nature conservation, the problem of isolating salt dumps from dissolving by precipitation is very topical, however, the specific micro-relief in the form of roughness resulting from precipitation, as well as the considerable porosity of the surface, create certain difficulties in arranging water-protective coatings. the use of some foams, in particular PensUplasts on the foundations of mymo-formaldehyde resins. The suitability of carbamide foams for isolating salt dumps is determined by their ability to cure and transfer to a harder and water-insoluble product at ordinary temperatures in the presence of sodium chloride and other salts that are part of salt wastes. a rather thick layer, on which then it is easy to apply a layer of film-forming material. A known composition for the preparation of a foam, comprising a Urea-formaldehyde resin, a frother, a septer, and water tl. I The disadvantages of foam plastic are low mechanical strength, as well as reduced crack resistance. The resulting coatings based on these materials. The closest to the technical essence of the invention is the well-known position of 21 for obtaining foam, including unlimited water-soluble urinary formaldehyde resin, as a frother, sulfonol, as a hardener, benzenesulfonic acid and water with the following ratio of components, hmdna resin Sulfonol (foaming agent) 0.8-0.9 Benzene sulphonic acid (curing agent) 1, -1.6 Water Rest Urea-formaldehyde foam obtained on the basis of this composition, has a low other awn compressive 0.5-0.6 kgf / cm and lower treHimichesky composition phosphogypsum feedstock wt.%

32.5 1.2 1.5

Depending on the conditions of production, Phosphogypsum can be obtained in two-water or semi-water forms.

When using semi-aquatic phosphogypsum, the resulting foam has .9

Apatite Tables

of

0.5 0.8

nineteen,

0.1

low mechanical strength (less than 1.0 kgf / cm). This is due to the fact that, during the process of foam foam curing, the field of the middle binder (carbamide resistance to 84) is quickly dehydrated. These drawbacks greatly inhibit the possibility of using this material as an equalizing (intermediate) layer for insulating solid salt wastes (salt dumps). from dissolution by atmospheric precipitation. The invention’s core is to increase the strength and crack resistance of the final product. The goal is achieved by the composition for producing a foam, including unrestrictedly soluble in water; urea-formaldehyde resin; foaming agent, hardener and water, additionally contain two-water phosphogypsum with the following ratio of components, parts by weight: Urea-formaldehyde resin (MFS) 125-175 Double-water phosphogypsum 150-250 Water 150-50 Frother iS 3 Orthophosphoric acid and other known compounds are used as hardeners. Sulfonol can be used as a foaming agent. Phosphogypsum is a waste generated during the processing of apatite raw materials. It is a white powder with a relatively large specific surface area. In terms of chemical composition, Phosphogypsum differs from natural gypsum in that, in addition to gypsum, it contains various phosphorus compounds, as well as a small amount of silica and one-and-a-half oxides (see Table 1).

resin) during the transition of gypsum from the semi-aquatic form Q to the form of a double hydrate.

The introduction of the bicurved phosphogypsum into the foam provides a material with increased mechanical strength, as a result of which it becomes possible to move people and light mechanisms along the flattened surface of salt dumps during the process of constructing and operating a protective coating.

In addition, the resulting foam has an increased crack resistance, as the two-water phosphogypsum introduced into the composition has a fibrous structure.

Example .. There are several mixtures, .. containing various amounts of unlimitedly water-soluble urine in the wine-formaldehyde, two-water phosphogypsum, sulfonol, orthophoric acid and water (see, Table 2, mixtures 1-5).

Before the introduction into the composition, the dowvod phosphogypsum is dried to a constant weight at CO-AO C and from a table. 2 shows that the greatest strength and the greatest crack resistance of the leveling (intermediate) layer will occur at flow. two-water phosphogypsum in the composition of the day composition from 150 to 250 weight.h. 125-175 weight. m. Urea through OITO with a size of 0.5 mm.

The preparation of a foam based on this composition provides the paths for mixing all of the above-mentioned components in a high-speed mixer in the presence of air. The mixture is poured into a cylindrical shape / meter and a height of 50 mm. After one day, the samples are removed and the next 9 days are kept in air-dry conditions at room temperature. After that, the samples are tested for compression.

To determine trecino resistance, a freshly prepared mixture of foam is cast in a form of plates about 10 mm thick on plywood 10 mm thick. After 10 days of hardening under the same conditions, the degree of cracking (in%) of the plates is determined in accordance with GOST 6992-60. The method for determining the stability of the coating in atmospheric conditions.

I.;

The test results are presented in Table. 2,

table 2

10 3 2

3 It

aldehyde resin (compounds 2-, tab. 2).

Within the specified intervals, the resulting foam has the best properties in terms of its possible use for salt dumping coatings.

79106788

Claims (2)

The invention of the hardener 2-3 Composition to obtain a foam-Water 150-200 one that includes urea formaldehyde two-phosphorus resin, a foaming agent, otverdi-gypsum 150-250 body and water, I distinguish you with information sources, so that, in order to increase the strength, taken into account in the examination of the final and crack resistance of the final pro-1. Valgin V.D. and Borodkina N.I. duct, it additionally contains Urea-formaldehyde foam bicarbonate phosphogypsum with the following co-MFP 2. Plastics, 197. the ratio of components, parts 10, s. kft-kj. Urea-formalde-2. USSR author's certificate hydama resin 125-175№, cl. 08 J 9/30, 1976 Frother -8 (prototype).