A.密封B.潤(rùn)滑C.磨損嚴(yán)重
A.細(xì)粒級(jí)物料得不到有效分選B.精煤質(zhì)量下降C.精煤質(zhì)量提高D.無(wú)影響
A.8%~15%B.10%~15%C.5%~10%