| 摘要 |
1,242,277. Reducing,alkaline,descaling bath. VALCOVNY PLECHU NARODNI PODNIK. Nov. 21, 1968 [Dec.5, 1967], No.55308/68. Heading C7E. A reducing alkaline descaling bath is prepared by making a preformed composition containing an alkali metal hydride, and as stabilizer therefor, an alkali metal oxide, and adding said preformed composition to a descaling bath containing an alkali metal hydroxide. The preformed composition may contain 40-50 wt% a.m. hydride, 1-20% a.m. oxide, and 30-59% a.m. hydroxide, and is made either by mixing the components together, or by reacting H2 at 1-100 atm at 250- 450‹C. with a mixture of 5 to 50 wt% alkali metal and an alkali metal hydroxide, and is added to an alkaline descaling bath, which may have been previously used, at 0-450‹C., preferably as a solid at 0-50‹C., or as a melt at 320-450‹C. The alkali metal is preferably sodium in all cases. |
