钪的有关问题暨滇中地区基性-超基性岩含钪性研究

Some Problems concerning Scandium and Scandium-bearing Potential of the Mafic-ultramafic Intrusions in Central Yunnan Province

钪是飞机、宇航器、原子能电站、高效多功能激光器、固体电解质、特种陶瓷、汽车、船舶、大功率金属卤素灯、太阳能蓄电池、体育器材等领域不可替代的战略矿产资源。滇中地区的基性-超基性侵入体,位于西昌-元谋基性超基性岩带的南端。这些岩体均属于热侵位的"阿拉斯加型"基性超基性岩,其成因与晚二叠世峨眉山地幔柱活动有关。在成矿特征和构造背景上均不同于哀牢山蛇绿混杂岩带内的冷侵位的"阿尔卑斯型"基性超基性岩(如双沟超基性岩)。滇中地区的基性超基性-碱性杂岩体的成矿作用,除了以往关注的铁(钒钛)矿化以外,普遍富含钪。尤以西昌—牟定地区基性-超基性岩含钪性好。二台坡杂岩体分异作用明显,由暗色端元和浅色端元两部分组成。其中的浅色端元,是一个由深灰色-浅灰色-灰白色的含磁铁矿正长辉石岩-角闪正长岩-二长岩组成的杂岩体,底部含磁铁矿正长辉长岩,磁铁矿含量20%左右,全铁(TFe)含量达9%,含Sc2O360～110g/t。目前,二台坡岩体已初步控制钪(Sc2O3)资源量720余吨。此外,在二台坡、凹溪河、碗厂等矿区也初步控制Sc2O3资源量6500吨。牟定-绿汁江基性-超基性岩带南北全长130余km,共发现同类基性-超基性岩体(群)60余个,含钪情况相当。由此推算滇中地区基性-超基性岩带中Sc2O3的资源远景有数万吨之巨,有望达到甚至超过四川攀枝花地区Sc2O3的资源量(3.87万吨),潜在经济价值巨大。

Scandium is a strategic mineral resource with irreplaceable importance for utilization in such fields as airplane,spacecraft,atomic power station,high-effective multi-function laser,solid electrolyte,special ceramics,motor vehicle,ships,high-power metal halogen lamp,solar energy storage battery,and sport equipment.The basic-ultrabasic intrusions in central Yunnan are located at the southern end of the Xichang-Yuanmou basic-ultrabasic intrusion zone.These intrusions,tectonically assigned to the ＂Alaska type＂ basic-ultrabasic intrusions and characterized by thermal emplacement,are products of the activities of Late Permian Emeishan Large Igneous Province （ELIP）.They are different in mineralization and tectonic setting from the ＂Alpine-type＂ intrusions resulting from the cold emplacement in the Ailaoshan Ophiolitic Melange Zone （such as the Shuanggou ultrabasic rock）.Mineralization of the basic-ultrabasic-alkaline intrusions in central Yunnan,besides iron （vanadium-titanium） mineralization focused previously,is generally of scandium mineralization.The Ertaipo complex,in particular,is characterized by distinctive fractionation,forming two end members：light-color and deep-color members.The Ertaipo intrusion （complex） is a light-colored member,consisting of dark gray magnetite-bearing pyroxene syenite,light gray hornblende syenite,grayish white monzonite,and magnetite-bearing syenitic gabbro （with magnetite 20%,or total iron 9%;Sc2O3 60-110 g/t）.The basic-ultrabasic intrusions are rich in scandium,of which the Ertaipo intrusion possesses Sc2O3 resource of above 720 tons.Together with the other intrusions in neighboring areas,such as Aoxihe and Wanchang,the total Sc2O3 resources have been up to 6500 tons,as revealed by work of recent years.The basic-ultrabasic intrusion belt from Mouding to Lüzhijiang is 130 km in length,within which there are more than 60 basic-ultrabasic intrusions （groups） of this kinds.It is estimated that the resources potential of Sc2O3 is up to several ten thousand tones,and the reserves are hopeful of attaining or excessing the Sc2O3 resources of 38700 tones in Panzhihua area,Sichuan.