黔北地区浣溪铝土矿床地质特征及控矿因素分析

黔北浣溪铝土矿床为产于石炭系黄龙组灰岩古侵蚀风化面或志留系韩家店组黏土岩、页岩、砂岩等侵蚀间断面之上的一水硬铝石沉积型大型铝土矿床,初步探明铝土矿资源量2000×104余吨。研究表明,浣溪铝土矿床地表矿体质量总体优于深部,地表矿体具有中铁、低硫特征,深部矿体具有中铁、高硫特征。矿石主要化学组分为Al2O3、SiO2、Fe2O3、TiO2及烧失量,占矿石组分的95%~98%,Al2O3与SiO2呈负相关关系;镓、锂是矿床的伴生有益元素。矿床的形成主要受地层岩性、向斜构造、古气候、古沉积环境等因素控制;炎热潮湿的古气候条件和半封闭海湾环境利于成矿。

Geological characteristics and ore-controlling factors of Huanxi bauxite deposit in northern Guizhou province

Huanxi Bauxite Deposit belongs to diasporite sedimentary bauxites deposit which was formed on paleo-erosion weathering surface of carbonate rock of Carboniferous Huanglong formation, or erosion discontinuity surface of clay rock, shale, sandstone of Silurian Hanjiadian formation. The amount of bauxite resources exceeds 20 million tons. Study of the deposit showed that the quality of ores at surface was better than those to depth, i.e., medium content of iron and low sulfur; ores to depth are of medium Fe content and high sulfur; the ore is mainly composed of Al₂O₃, SiO₂, Fe₂O₃ and materials of ignition loss, about 95%~98% of the total, and Al₂O₃ is negatively correlated with SiO₂; Gallium, lithium were major beneficial elements. The formation of ore deposit was controlled by lithology, syncline structure, paleoclimate and paleo-sedimentary environment. Bauxite ore occur under condition of semi-closed bay and warm and wet paleoclimate environment.