Insulating coatings; coatings of insulating materials; industrial coatings (insulating); surface coatings; wet coating materials for use in the ferrous and non-ferrous metal melting industries; ceramic coatings; binding agents; surface coatings and binding agents for ceramic fibre and other fibrous insulation material; zircon coating; zircon based refractory composition powders; coatings for improving fibre surfaces; insulating coatings in dry powder form; refractory materials; refractory coatings; refractory coatings of zirconium powder; insulating refractory materials; industrial ceramic materials