FIRE-RESISTANT MIXTURE AND MULTICOMPONENT MATERIAL FOR PROTECTIVE COATINGS OF HEATING ELEMENTS BASED ON LANTHANUM CHROMITE MADE FROM SAID MIXTURE Russian patent published in 2010 - IPC C04B35/505 C04B41/87 

FIELD: chemistry.

SUBSTANCE: invention relates to heat-resistant nonmetallic materials and can be used to make effective protective coatings of heating elements based on lanthanum chromite working in an air atmosphere. The invention involves use of a heat-resistant mixture composed of lanthanum chromite, frits from oxide phases and aluminoborosilicate glass with the following ratio of ingredients, in wt %: lanthanum chromite 32-44, frit 43-48, aluminoborosilicate glass 13-20. The frit from oxide phases contains the following components, in wt %: yttrium oxide Y₂O₃ 63-65, aluminium-magnesium spinel MgAl₂O₄ 13-21, lanthanum aluminate LaAl₁₁O₁₈ 6-13, mullite Al₆Si₂O₁₃ 6-13, aluminoborosilicate glass SiO₂ 53-55, CaO 18-20, Al₂O₃ 13-15, B₂O₃ 9-11, MgO 2-4. The multicomponent material for protective coatings obtained from the mixture contains crystalline phases and a glass phase in the following ratio, in wt %: LaCrO₃ 29-42, Y₂O₃ 30-31, MgAl₂O₄ 6-8, LaAl₁₁O₁₈ 3-5, Al₆Si₂O₁₃ 3-5, aluminoborosilicate glass phase 16-22.

EFFECT: fire-resistant mixture and multicomponent material provides strong adhesion of protective coatings to the surface of heating elements based on lanthanum chromite, prevention of crack formation and flaking of protective coatings during thermal cycles, longer life of heating elements with the protective coating.

2 cl, 7 ex, 4 tbl, 1 dwg