某铁矿为含铜混合矿石,铁矿物以磁铁矿、赤褐铁矿和菱铁矿的形式存在,铜矿物主要有黄铜矿、少量斑铜矿,含有少量黄铁矿,伴生有金钴等贵重元素。分选过程中除回收铁矿物外,要求同时得到铜精矿和硫精矿。根据矿石性质,通过浮选条件试验和流程试验,采用混合浮选-分离浮选-弱磁选-强磁选原则流程,一段磨矿(磨矿细度为75%-0.076mm),可以获得含铜16%以上的铜精矿、含硫36%以上的硫精矿、含铁62%以上的弱磁铁精矿,强磁铁精矿铁含量仅32%-36%;采用铜硫粗精再磨(磨矿细度为90%-0.076mm)再选流程,试验指标进一步提高,铜回收率提高4.44%、硫精矿品位提高1.10%、硫回收率提高1.78%,强磁铁精矿铁含量提高3.84%。由于试样磁黄铁矿含量较高,致使弱磁铁精矿含硫偏高,采用弱磁选精选无法进一步降低,建议对弱磁铁精矿进行反浮选脱硫提铁处理。
A mixed iron ores containing copper has iron minerals in the forms of magnetite,hematite limonite and siderite,and copper minerals mainly in chalcopyrite and a small amount of bornite,in addition a small quantity of pyrite,associated gold,cobalt and other precious elements.Besides the recovery of iron minerals in mineral process,copper concentrate and sulfur concentrate are required.According to the nature of the ore,condition flotation tests and process flotation tests were finished.With mineral process of bulk flotation-separation flotation-low intensive magnetic separation-high intensive magnetic separation,a copper concentrate with copper content above 16%,a sulfur concentrate with sulfer content above36%,a low intensive magnetic iron concentrate with iron content above 62%,and a high intensive magnetic iron concentrate with iron content of 32%~36%were achieved in the primary grinding with fineness of 75%-0.076 mm.By copper and sulfur concentrate regrinding and flotation processing at grinding fineness of 90%-0.076 mm,results of the tests were improved further.Copper recovery,grade of sulfur concentrate,recovery of sulfur,iron content of high intensive magnetic iron concentrate were respectively increased by 4.44%,1.10%,1.78%,3.84%.High pyrrhotite content in the ore resulted in high content of sulfur in low intensive magnetic iron concentrate,which cannot be further reduced by low intensity magnetic separation.Thus,a reverse flotation desulfurization was recommended to increase iron content.