云南某胶磷矿AMICS工艺矿物学研究及其难选机理探讨

Mineralogical analysis of collophane in Yunnan using AMICS and exploration of difficult flotation mechanisms

为了深入探讨胶磷矿难选的具体原因,采用化学分析、X射线衍射以及矿物自动分析系统(AMICS)测试手段对云南某胶磷矿浮选给料进行了系统深入的工艺矿物学研究,探索了该矿样难浮选分离的内在机理.结果表明:该样品中磷主要以氟磷灰石形式存在,其脉石矿物以白云石和石英为主.氟磷灰石的嵌布粒度较细,主要分布于10~75μm的粒度范围,其单体解离度为59.17%.除了以单体的形式存在以外,氟磷灰石主要与白云石、石英连生,连生体的质量分数分别为26.23%和9.92%.而白云石和石英的单体解离度相对较低,分别为46.82%和39.10%.进行了粗选脱镁、一粗两扫脱硅的闭路流程浮选试验,获得了精矿P_(2)O_(5)品位为29.75%、P_(2)O_(5)回收率为81.95%,SiO_(2)品位为12.63%的浮选指标.结合工艺矿物学分析结果,指出该浮选样品中胶磷矿嵌布粒度细、难以获得较好的解离度、泥化严重是浮选难于获得更好指标的主要原因.

It is a global fact that the mineral ores degrade to the poor grade status and the various properties of ores are adversely altered such as fine dissemination and complex composition due to the continuous exploitation and utilization of phosphate rock resources.Consequently,separation of minerals has become a difficult and daunting task.The automatic mineral identification and characterization system(AMICS)is mostly used only for mineral characterization.There is no much research and literature on process mineralogy that integrates research parameters with flotation test results to quantitatively explore the mechanism of difficulties or problems faced during mineral separation.In this paper,to further explore and analyze the specific reasons for difficult problems faced while separating collophanite,a systematic in-depth mineralogical analysis based on the chemical analyses,X-ray diffraction,and AMICS has been performed on a refractory collophane flotation feed sample from Yunnan,China.The results show that the phosphorus in the sample mainly exists in the form of fluorapatite and also present in the gangue minerals,which are primarily dolomite and quartz.Fluorapatite has a fine dissemination particle size,which is in the range of 10-75μm with a degree of mineral liberation 59.17%.Apart from existing in the form of liberated particles,fluorapatite is also present in dolomite and quartz as a composite particle and the mass fraction of composition in dolomite and quartz is found to be 26.23%and 9.92%,respectively.Further,dolomite and quartz relatively have a low degree of mineral liberation with the liberation degree of 46.82%and 39.10%,respectively.The closed-circuit flotation test was carried out with a rougher flotation to remove magnesium.Further a roughing and two stages of scavenging is performed which obtained the flotation performance of concentrate P_(2)O_(5) grade of 29.75%,P_(2)O_(5) recovery of 81.95%,and SiO_(2) grade of 12.63%.When the results were studied together with the mineralogical analysis results,it is found that the fine dissemination particle size of collophanite,the poor degree of mineral liberation,and the serious slime generation are the main causes for not able to achieving a better performance in separation of minerals.