黔西南册亨板其磷矿矿石结构与成矿过程

Ore Structure and Mineralizing Process of the Banqi hosphorite deposit in Ceheng County,Southwestern Guizhou,China

在矿床分类中并未对洞穴堆积磷矿床的矿质沉淀过程及制约因素进行分析。本文通过显微镜结合双束扫描电镜对贵州板其磷矿矿石结构研究中发现,洞穴堆积磷矿床矿物组成成分有磷灰石、菱锰矿、软锰矿、少量的菱铁矿、自生石英及方解石等,矿石主要为胶状结构,条带状、栉壳状及蜂窝状构造。板其磷矿矿物构造特征与潜水带喀斯特溶洞内的微型流水石具有极其相似的特征,推测洞穴堆积磷矿床中磷质及锰质的沉淀实际为水介质pH值的变化导致其溶解度变小而析出的过程。与钙华形成机制对比后,将因水介质pH值变化后导致磷质析出的磷灰石命名为"磷华"。

In the classification of deposits,the process and controlling factors of mineral precipitation of the cave phosphorus deposit are not analyzed.In this paper,by using the combination of optical microscope and double beam scanning electron microscope,ore structures of the Banqi phosphorite deposit in Guizhou Province have been studied.It is found that ores of the cave phosphorus deposit contain mineral components of apatite,rhodochrosite,pyrolusite,and a small quantity of siderite,authigenic quartz and calcite,etc.,and have dominant colloidal,banded,ctenoid,and honeycomb structures.It is inferred from the high similarity of the mineral structure characteristics of the Banqi phosphorite deposit and micro flow stones in Karst caves of the phreatic zone that the deposition of phosphorus and manganese in the cave phosphorus deposit was actually resulted from the decrease of phosphorus and manganese solubilities caused by the change of pH value of water medium.After comparing with the formation mechanism of calc-sinter,the apatite formed by the precipitatation of phosphorus due to the change of pH value of water medium has been named"phos-sinter".