Rouge to be used as abrasive for buffing after copper plating is made by calcining iron ore, ocker, etc., but rouge for buffing gold, silver and other soft metals made by calcining salts of iron.
Electron-microscopic observations on size and shape of grains produced by calcining salts of iron being made, the following results were obtained;
1. As for rouge made by calcining ferrous sulphate or iron-ammonium sulphate, the grain becomes larger in size with higher calcining temperature and with longer heating-time. The shape of the grain is round or subangular in any cases.
2. As for rouge made by calcining ferric chloride, the shape of its grain is sub-angular or subcrystalline of needle style. In order to make rouge of fine grain, it is essential to calcine the material at low temperature and in short time.
抄録全体を表示