五十年代初,我国一些选煤厂如本溪、滴道等大都采用斗子捞坑。而五十年代末及六十年代初,因外援建的厂,例如双鸭山、马头等选煤厂均予舍弃。多年来的生产实践表明,斗子捞坑的优点不仅在于简化流程、水力分级效果良好;同时对稳定生产系统的可靠运行亦发挥了巨大的缓 In the early 1950s, some coal preparation plants in our country, such as Benxi and Dadao, adopted bucket cranes. In the late 1950s and early 1960s, plants built for foreign aid, such as Shuangyashan and Matou, were abandoned. Years of production practice have shown that the advantages of a bucket pit are not only to simplify the process but also to have a good hydraulic grading effect; at the same time, the reliable operation of a stable production system has also been tremendously slow