| 摘要 |
Removal of silicates, i.e. glass and silicate melt from fireproof lining, from the surface of platinum objects, is performed by intermittent short-term submersion both into a dissolution bath, containing hydrofluoric acid above 25 % by weight at the temperature of the surroundings, and into a rinsing bath containing sulphuric acid at a concentration above 63 % by weight, at a temperature above 64 degrees C. Gaseous products of dissolution are sucked off and subsequently absorbed. Dissolution occurring insoluble salts are rinsed in the rinsing bath, which preferably is subject to intensive agitation, for example by pressurised air, mixing, and mechanical movement of the platinum objects. The solution is relatively fast, accessible, safe and hygienically safe.
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