我厂20m~3小高炉冶炼用的是利国块矿,共分三级:大块35—45mm,中块10—22mm,小块5—8mm(由于矿石供应不足,为维持生产将破碎筛下的粉矿重新用5×5mm筛网过筛筛出5—8mm小粒矿)。三级矿石分别分阶段入炉,所作试验比较如下: 一、分级入炉试验情况我厂共用了4200吨矿石分级入炉其中大块约占1000吨,中块700吨、小块2500吨,每种粒度矿石冶炼10—20天,冶炼周期由大块到小块。在分级分阶段冶 I plant 20m ~ 3 small blast furnace smelting is the country block ore, is divided into three levels: large 35-45mm, in the block 10-22mm, small 5-8mm (due to lack of ore supply, to maintain production will be broken sieve Under the re-use of 5 × 5mm powder sieved sieve 5-8mm sieve small particles). Three ore were staged into the furnace, the test is compared as follows: First, the classification into the furnace test situation I plant a total of 4,200 tons of ore classification into the furnace which accounted for about 1,000 tons of large, 700 tons in the block, 2500 tons of small pieces, each Grain size ore smelting 10-20 days, smelting cycle from large to small pieces. Staged in the metallurgical grade