Producer
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Annotated report beyond the theme: “Testing of paints due to the conditions of potassium production” The joint stock company “Of [uralkaliy]” the laboratory of potassium testing (ЛИК)
The equipment for [gallurgicheskogo] production is exploited due to the conditions of the moderately aggressive media, when the rate of the corrosion of metal exceeds 0,5 mm/year (data of 1992 g, been [VNIIGom] Perm'). Limited application of alloy steels leads down an increase in the volumes of production through carbon steel with the subsequent protection for the sake of its chemically steadfast nonmetallic materials. Putting beyond its surface of paint and varnish coats is the most effective and accessible method of corrosion prevention of metal. 1. Purpose of the work Performing this work is caused by the need of selecting anticorrosive coatings for the protection of the internal surface of the reservoirs, filled for the sake of the hot for the sake of the solutions of salts of chlorides K and Na. The same are backup tanks on factory [BPKRU]-4 pos. B -517-8 and pos. of 4.2-2F01. 2. Technical description a) Technical characteristics of tank B -517-8
NOTE: The following protection was executed against the moment of bringing into service of vertical reservoir pos. B -517-8. (91-92 yr.) On the bottom - brick lining by acid-resistant brick on the fiberglass fabric on epoxy-bakelite connecting; on the wall - brick lining by acid-resistant brick on the fiberglass fabric down a height of 30 cm; remaining vertical surface 4 fiberglass fabric on epoxy-bakelite bonding agent. b) With the inspection of the state of the internal surface of tank pos. B -517-8 in September 2002. it is established that the protection remained before the satisfactory state only on the bottom, the protection is absent on the walls, metal is covered for the sake of the thick layer of stratified rust. 3. Preparation at the point of the tests 3.1. Brief characteristic of the polymeric materials of those selected for the tests. a) epoxy resin possess hardness, waterproofness, chemical resistance and other valuable shielding properties. However, before the pure form they do not adapt on a number of technological and economic reasons, since have the increased viscosity, the high coefficient of temperature expansion, the low deformations; unsatisfactory adhesion, brittleness and high cost. For reduction in cost and giving to epoxy resin of the necessary properties (increase in heat resistance and decrease of brittleness) they are modified, i.e., are introduced plasticizers, hardeners, fillers, the pigments or combine with others those form filming, which even more enlarges the possibilities of their application. In this work we selected two diagrams of protective coatings on the basis of epoxy resin ED-20, modified by the thermoresistant materials:
NOTE: The relationship of components is indicated beside [p].3.2. b) beside the anticorrosive group “of LIK” of joint stock company “Of [uralkaliy]” entered the test batch of paints “[Unipol]”, the producer [OOO] “OF [NPK] “Of [korrzashchita]” Moscow. Priming enamel [SBE]-111 “Of [unipol]” “of the stamp “B” (diagram 3) is intended for the corrosion protection of metal structures and equipment through the low-carbon, the zinc-coated and stainless steel, aluminum and its alloys, which work before the aggressive media (warehouse accomodations, transport for the transportation of the mineral fertilizers, conduits, containers, drain chutes, reservoirs and roofs) at a temperature from minus of 10°C to plus of 100°[S]. 3.2. Diagram of the protective coatings Diagram of № 1:
Diagram of № 2:
Diagram of № 3:
3.3. As the base layer were used metallic plates through steel Of [st].3, by the size of 70[kh]20[kh]2 mm. surface was sandblasted down the degree “2” ALL-UNION STATE STAN. 9.402-80. The application of coatings was produced with t=20±2°C with the subsequent drying during 7 days under the same conditions. 4. Conducting the tests Conducting laboratory tests according to GOST 9.083-78 “coatings are varnish-and-paint. Method for the accelerated length-of-life tests before the liquid aggressive media”. The method for testing consists before maintaining of models before the aggressive media of the potassium production: the saturated solution of salts Of kCl and NaCl, to sulfuric acid 25%, to water for the sake of the subsequent visual evaluation of the durability of coating about a change in the decorative and shielding properties. In this case are compared exterior view coatings before and after of the tests: a change in the color, the appearance of bubbles, rash, cracks; the adhesion of protective film to the metallic step, the state of metal under the coating. The results of visual inspection are carried beside Table 1. Determination of the adhesion: Adhesion determined about the method of lattice cuts in accordance with ALL-UNION STATE STAN. 15140-78. The essence of method consists before the putting beyond the paint and varnish coat of lattice cuts and the estimation on four ball scale (1 mark - exfoliation is not observed; 4 marks - exfoliation are more than 35%). 5. Results of the tests 5.1. As a result the inspection of models after tests before the water with t=80°[S] it is noted:
5.2. Coating state after tests before the acid H2SO4 25% with t=+60°[S]
5.3. Coating state after tests before the solution of salts with t=+80°[S].
Opposite the state of metal under the protective films it is possible to draw the conclusion that all three coatings are impenetrable for the water, acids, lye, t to metal under the films after the tests of light grey - silvery color without the products of corrosion. 6. Conclusions On the basis obtained results it is possible to draw the conclusion that the coatings on the basis of epoxy resin ED-20 are chemically resistant and sufficiently thermoresistant before the solution of salts (to 80°[S]). Modification by organ- silicate paint or by bakelite varnish does not entirely contribute down an increase in the elasticity of resin and it does not respectively improve the adhesion of epoxy compositions to the metallic surface. It is of interest to test data of coating after the introduction before them of plasticizer from the row of dibutyl phthalates. New coating priming enamel “Of [unipol]” differs from epoxy materials regarding elasticity, satisfactory adhesion, the presence beyond the surface of the treatment of the craters, which increase before the water with t= +80°[S]. in order to avoid the disturbance of the continuity of coating, is drawback, it must be brought at the point of several layers, to the thickness 400 m (recommendation of producer). We consider possible application before the experimental-industrial order of priming enamel “Of [unipol]” for the protection of reservoir at the factory [BPKRU]-4 pos. B -517-8 the thickness of coating not less than 400 m. Chief of the anticorrosive group “of LIK” OF [T].[V]. [Verbitskaya] Results of the laboratory tests of paints OS -12-03+[ED]-20, epoxy-bakelite composition, priming enamel [SBE]-111 “Of [unipol]” Test conditions: Table of №1.
Test conditions: Table of №2.
Test conditions: Table of №3.
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