在铸钢件生产中,除耗用一定数量的新砂外,还必须回收大量的旧砂作为填充砂。根据测定,每吨铸钢件的旧砂需用量为2～2.5吨,如以我厂为例,每天就要处理旧砂20吨左右。过去我厂制备填充砂是将打箱后的旧砂用人工筛分,筛分是在一个用一木棍支撑起来的大筛孔筛上进行(工人用铁锹将旧砂扬上去)。这样筛分,如每天需 Cast steel production, in addition to consumption of a certain amount of new sand, you must also recover a lot of old sand as filling sand. According to the test, the required amount of used sand per ton of steel castings is 2 ~ 2.5 tons, for example, in our factory, about 20 tons of used sand should be treated daily. In the past, the factory prepared sand filling sand was used to screen the artificial sand after boxing. The sieving was carried out on a large sieve supported by a wooden stick. This screening, such as daily needs