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  4. METALS AND THEIR TREATMENT
化學(xué)配方數(shù)據(jù)庫(kù)
配方類型： METALS AND THEIR TREATMENT
配方說(shuō)明： Cleaning Old Coins
配方組成：
配制方法： Use a small stainless steel pan as an anode and the corroded coins as cathodes. The pan is filled with a 2% solution of sodium hydroxide, and the coins dangle from alligator clips into the bath. When a direct current from a small battery charger (12 volts, 950 milliamps) is applied across the circuit the coins literally clean themselves.

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