the test results show that the whiteness of high-grade grammite powder can be increas4ed from 72 to 84 by using single high-intensity magnetic separation, and the one of low-grade grammite powder containing carbonaceous materials from 62 to about 81 by using the hims-airflow pulverising-flotation flowsheet 試驗結(jié)果表明,采用單一強磁選方法可將硅灰石富礦粉的白度由72提高到84;采用強磁選-氣流粉碎-浮選新工藝可將含碳質(zhì)物的硅灰石貧礦粉的白度由62提高到81左右。