| 摘要 |
Process for treating the surface of a solid article made of a material having a vitreous structure, such as crystal, lead glass and the same, and containing som e amounts of heavy metals such as lead, said surface being liable to be into conta ct with products of acid character, such as alcohols e.g cognac, whisky, wines or f ruit juices, or acid foodstuffs, with a view to prevent said heavy metals from drifti ng into said acid products, characterized in that it comprises forming in a superficial area of said surface, after partially removing the lead ions from said area, a silico-al uminous diffusion barrier opposing said drift into said acid product, by ion exchange be tween said material having a vitreous structure and a coating temporarily laid upon sa id surface, said coating comprising a silico-aluminous crust resulting from the hea ting of a kaolin layer laid upon said surface under the form of a thixotropic barboti ne of pure hydrated aluminium silicate.
|
