高镁磷尾矿中钙、镁、磷赋存状态研究

The Study on Existing State of Calcium,Magnesium and Phosphorus in Phosphorite Tailings with High Magnesium Content

选择了贵州省重要磷矿生产基地—瓮福磷矿浮选尾矿为代表,对其中钙、镁、磷的矿物学重要特征进行了比较系统的研究,获得了一些重要结论,从而为高镁磷尾矿的综合利用、白云石与胶磷矿的分离等提供理论依据,对实现磷尾矿资源的二次利用、指导开发者设计科学合理的矿石选冶工艺流程都有十分重要的意义。按照元素赋存形态分析的方法,选用了化学成分、化学物相、电子能谱、扫描电子显微镜、X射线粉晶衍射分析方法等多种手段系统、全面地测定了磷尾矿结构、形貌的重要特征,获得了钙、镁、磷赋存状态的重要结论,发现了尾矿及其原矿的异同性:磷尾矿中含量最高的组分及其含量分别是:氧化钙34.11%,氧化镁17.65%,五氧化二磷5.30%;镁主要以白云石的形式赋存,并有少量以磷酸盐、硅酸盐形式存在,其在各相占的比例分别为99.80%、0.10%、0.10%;磷主要以磷灰石的形式赋存(占97.08%),并有少量以铁氧化物(1.04%)、独居石(0.19%)、磷钇矿(1.83%)形式存在;钙主要以白云石的形式赋存(占96.95%),并有少量以方解石(1.11%)、磷酸盐(1.94%)形式存在。贵州瓮福地区高镁磷尾矿中的镁、磷、钙主要赋存形式分别为白云石、磷灰石、白云石。

In this paper, we chose the floated phosphorite railings in Wengfn, a key base for producing phosphorus in Guizhou province, as an example for conducting systematic research on the mineralogical characteristics of calcium, magnesium and phosphorus in the tailings. We drew a few important conclu- sions from the research, which provides the theoretical bases for developing the comprehensive methods for utilization of phosphorite tailings with high magnesium content as well as for the separation of dolomite and collophanite. Furthermore, the applications of the method will be significant for the re-utilization of phosphorite tailings and designing reasonable ore extraction process.A few analytical approaches for characterizing element existing state, which include chemical analysis,chemical phase analysis, electron spectroscopy analysis, scanning electronic microscope analysis and X-ray diffraction analysis, were utilized to systematically and thoughtfully characterize the structure of phosphor- ite tailings and their important topographic features. The vital analytical results for the study of existing state of calcium,magnesium and phosphorus were obtained. The similarity and difference between tailings and its originals were also analyzed. According to the measurement of phosphorite, the highest content of the tailings are calcium oxide, magnesium oxide and phosphorus pentoxide with the concentrations of 34. 11%, 17.65% and 5.30%, re- spectively. Meanwhile, the phase analysis indicates that the existing state of magnesium is mainly dolo- mite, which accounts for 99.80% of the studied phosphorite tailings. And there are also a small amount of phosphate and silicate in it and each has the concentration of 0.10%. Additionally, phosphorus exists pre- dominantly in the form of apatite with the percentage of 97.08, and it also contains a bit of iron oxide, monazite and xenotime with the concentration of 1.04%, 0.19% and 1.83%, respectively. Contemporari- ly, calcium exists primarily in the form of dolomite, with the content of 96.95%, and it also contains a small amount of calcite and phosphate with the percentage of 1.11 and 1.94, respectively. Therefore, dol- omite, apatite and dolomite are the main existing states of magnesium, phosphorus and calcium in the phosphorite, respectively.