先讲几个理念。第一,废钢是一种炼钢不可缺少的资源,没有废钢就不能炼钢,这是由炼钢工艺决定的。第二,废钢铁是铁矿石的唯一替代品,但是铁矿石不能完全替代废钢,只能部分替代废钢。第三,铁矿石是一种原生资源,原生资源是有限的,总有采尽的时候。废钢铁是再生资源,是无限的。也 First talk about a few ideas. First, scrap is an indispensable resource for steelmaking, and steelmaking can not be done without scrap, as determined by the steelmaking process. Second, scrap iron is the only alternative to iron ore, but iron ore can not completely replace scrap and can only partially replace scrap. Third, iron ore is a native resource, with limited resources available and when it is exhausted. Scrap iron is a renewable resource that is unlimited. and also