我厂在土铁土焦利用中遇到了严重的困难,由于土铁硫高,含磷、硅低,土焦灰分大,含硫也高,燃烧温度低,每炉只能化3—4吨铁水。由于铁水温度低,流动性差,冷却快,常常发生出铁口堵塞以致冻炉而被迫停炉事故;加以我厂缝纫机零件的特点是小而薄,最厚的铸件为8公厘,大多数的铸件厚度在3—5公厘,如 I plant in the iron soil coke utilization encountered serious difficulties, due to iron soil high sulfur, phosphorus, silicon low, large soil ash, sulfur is also high, the combustion temperature is low, the furnace can only 3-4 tons molten iron. Due to the low temperature of molten iron, poor fluidity and fast cooling, it is often the case that the taphole is clogged to freeze the hearth and forced to shut down. The features of our sewing machine parts are small and thin, the thickest castings are 8 mm, and most The casting thickness of 3-5 mm, such as