| 配制方法： |
Ammonium bifluoride solutions containing some additional ammonia will remove siliceous materials from steel parts without materially corroding the steel. hence, steel tanks are suitable for containers for such applications. the castings can be cleaned in a solution of 350 parts of ammonium bifluoride and 75 parts of aqua ammonia 26 Baume in 500 parts of water, at or near the boiling point of the solution, in ventilated steel tanks. The length of treatment may vary from five minutes to one hour, depending upon the depth of scale. It is often advisable to immerse only long enough to soften the scale so that it can be readily brushed from the parts. |