SU667315A1 - Burn-on preventing coating for moulds and cores - Google Patents

Description

FIELD OF THE INVENTION The invention relates to the field of alcoholic beverage production, namely to anti-stick coatings for casting molds and cores. A nonstick coating for casting molds and cores, containing refractory filler, phosphoric acid, aluminum hydroxide, chromium oxide, water and fluorite, is known. However, the WTO coating must be dried at a high temperature, and it has insufficient strength and refractoriness. The closest to the invention in its technical essence and the achieved result is a nonstick coating based on distane sillimanite, water of bentonite, sublum lye, sulphite-arzhej brew and chromomagnesite {2 The disadvantages of nonstick coal are the necessity of drying it at high temperature, low surface strength, heat resistance and fire resistance. The purpose of the invention is to provide the ability to self-harden a nonstick coating, increase surface strength, fire resistance and heat resistance. This goal is achieved by the fact that the non-stick coating additionally contains concentrated phosphoric acid in the following ratio of ingredients, wt.%: Chromomagnesite6-18 Bentonite1-2 Sulfite yeast cream5-10 Orthophosphoric acid concentrated 1О-20 Water5-10 Piston-hydroaluminate. Instead of kyanite-sillimanite, dust-like materials, crystalline or fused quartz, electrocorundum, chamotte, zircon, etc. are used as a filler. Self-hardening of the nonstick coating at ceramics temperature occurs due to the interaction of orthophosphoric acid and chromium magnesite powder. High strength magnesium and capsid phosphates are formed: MgHPOv / iO; Mdsch) 2ENLSaPRO Co (H, RO,) - N. O; SANRO, SAS.RO,); Ca (OH) - (PO). The formation of phosphate compounds contributes to the preparation of a highly heat-resistant phosphate composition at the interface of the metal-farming mixture, which has a high chemical resistance to the molten metal and its oxides. The orthophosphoric acid in the composition of the nonstick coating increases its heat resistance and refractoriness, since under the action of high temperatures it condenses to polymerized metaphosphoric acid (). The latter, under the action of high temperatures, during the casting of molds with metal, turns into a coke residue with high mechanical properties, capable of withstanding a certain time, like magnesium phosphates, a high temperature. The sulphite-yeast brew participates in the formation of phosphate compounds and contributes to an increase in the adhesion strength of the nonstick coating to quartz grains. At the same time, it will increase the adhesion strength of the nonstick coating, which is important for mechanical effects on the shape or core. Chromomagnesite (GOST 10888-64) is ground in ball mills to a fraction of no more than 100 microns. Phosphoric acid is taken concentrated with a specific weight of 1.601, 80 g / cm. Sulfite yeast brew is taken with a specific weight of 1.18-1.22 g / cm. First a liquid composition is prepared consisting of phosphoric acid sulphite-yeast brew and water. Then a liquid composition is poured into the paint-sheet and bentonite and kyanene-sillimanite are introduced, after mixing for 1–15 min, chromium magnesite is introduced and mixed for another 15 min. The compositions and properties of nonstick coatings are given in table. 1 and 2. Table 1

58 9 10

1014 16 2O

57 10 6

1222 Specific gravity, g / cm Viscosity according to B3-4, with Self-sealing time, min

four

1O

2

Table 2 1.68 1.66 22 21.5 5O 45 1.6781.67 1.79 2222 19 404 It does not harden

Abrasion resistance, g sand

Refractoriness, C

Heat resistance after heating at YuOO C for Yu min, g of sand

Claims (2)

Sedimentation: stable,% When the content of chromomagnesite exceeds 18%, the self-sintering speed of the coating increases and decreases: zhivuchuyu. The implementation of the invention improves the quality of castings and labor productivity, reduces the complexity and cost of manufacture of castings. Claims of non-stick coating for casting molds and cores, include, in particular, kyanite-sillimanite, sulphite-yeast mash, chromomagnesite, bentonite, water, different from the fact that; In order to ensure its self-solidification, increase surface strength, heat resistance Continued table. 2 4450 4780 5650 7O 1930 193JA 194O 1920 1900 1950 21OO DA 4 bones and refractoriness, it additionally contains concentrated orthophosphoric acid in the following ratio of ingredients wt.%: Chromomagnesite6-18 Bentonite1-2 Sulphite yeast cream5-10 Concentrated orthophosphoric acid10-2O Water5-1O Pistan-sillimanite Ostno Sources of text objects that are also used to be used by the syllables of the rest of the ingredients. attention during examination 1. USSR author's certificate number 4O7625, cl. In 22 С З / ОО, .1972. 2. USSR author's certificate number 529822. class. B. 22 C 3 / OQ 1975.