内蒙某多金属矿微细粒锡富中矿回收选矿试验研究

Experimental Study on Beneficiation of Fine-grained Tin-rich Middlings from a Polymetallic Ore in Inner Mongolia

内蒙某含砷铁锌铜锡钨多金属矿选矿厂采用磁—浮—重—浮原则工艺流程综合回收铁、铜、锌、锡、钨后的尾矿中还含有Sn 0.25%的微细颗粒锡石,采用锡石浮选获得含Sn 3.58%的浮选精矿,即锡富中矿。锡富中矿虽然矿物组成简单,但主要有价矿物锡石结晶粒度细,与铁、脉石等矿物共生关系密切,这对锡石的回收影响较大;同时,富锡中矿中-5μm粒级产率高达40.03%,锡金属分布率达到10.22%,对锡石的分选极为不利,增加了锡石回收的难度。为了更好地回收这部分锡石,采用浮选、摇床+皮带溜槽重选及新型振旋球面选矿机选矿的方法进行了详细试验研究,结果表明,采用新型振旋球面选矿机进行全粒级入选获得的试验指标优于锡石浮选和重选。因此,最终推荐采用以新型振旋球面选矿机重选—重选精矿浮选除砷的联合选矿工艺流程,获得了锡精矿含锡32.59%、锡回收率为78.13%的良好指标。

A concentrator of a polymetallic ore containing As,Fe,Zn,Cu,Sn and W in Inner Mongolia adopted the flowsheet of magnetic separation-flotation-gravity separation-flotation to comprehensively recover Fe,Cu,Zn,Sn and W.The tailings contained 0.25%Sn-containing cassiterite and the cassiterite flotation was adopted to obtain a flotation concentrate containing 3.58%Sn,namely Sn rich middling.Although the mineral composition of tin-rich middlings was simple,the main valuable mineral cassiterite had a close paragenesis relationship with iron and gangue minerals,which had a great influence on the recovery of cassiterite.At the same time,the yield of-5μm fraction in tin-rich middling is up to 40.03%,and the tin distribution rate was up to 10.22%,which was extremely unfavorable to the separation of cassiterite and increases the difficulty of cassiterite recovery.In order to recover this part of cassiterite better,flotation,tabling+belt chute gravity separation and new type of vibrating and rotating spherical concentrator were used to conduct a detailed experimental study.The results showed that the test indexes obtained by using the new type of vibrating and rotating spherical concentrator for full size fraction separation was better than that of cassiterite flotation and gravity separation.Therefore,a combined beneficiation flowsheet of gravity separation by a new type of vibrating and rotating spherical concentrator and flotation for arsenic removal from the gravity concentrate was finally recommended,and a tin concentrate containing 32.59%tin with a tin recovery of 78.13%was obtained.