湖北鹤峰磷矿走马矿区岩湾矿段风化磷块岩特征及其形成的制约因素

湖北鹤峰磷矿走马矿区岩湾矿段的原生磷矿经化学风化作用后,矿层的厚度、矿石的品位、组分、类型、结构构造和其他物化特征产生了一系列变化,所形成的风化磷块岩主要特征表现为易溶的碳酸盐组分大量流失,磷酸盐组分相对富集;矿石结构疏松,呈“砂状”构造,从而使原生贫矿富集为风化富矿——风化磷块岩。形成该矿床的制约因素,除其固有的特征外,酸性地下水是风化矿形成的化学基础,适宜的气候条件以及地形、岩溶地貌等,对风化磷块岩的形成和分布有着重要的控制作用。

CHARACTERS AND GENETICALLY CONTROLLING FACTORS OF WEATHERED PHOSPHORITES FROM YANWAN MINING BLOCK,ZOUMA MINING DISTRICT,HEFENG PHOSPHATE DEPOSIT,HUBEI

The primary phosphate rocks from the Yanwan mining bolck of the Zoumamining district of the Hefeng phosphate deposit,with chemical weathering conductingall the time,have become reformed in many ways,such as thickness,grade,paragenesis,ore type,texture and structure,and other physicochemical natures.Such'a series of reformations led eventually to what is called weathered phosphoritecharacteristic of considerable loss of the soluble carbonate components,relativeenrichment of usful phosphate components and textural looseness of ores to take assandlike.All this means the primary poor ores have developed into rich ones,asweathered phosphorite is called today.The preconditions concerned with the depositformation,we conclude,in addition to the intrinsic physicochemical attributes of itsown,still include acid subsurface waters flowing about the mining area andfavorably climatic and geographic(particularly karst landform)envirnments whichhave contributed much to its enrichment and distribution.