陕西华阳川铀多金属矿床矿石特征及铀的赋存状态

华阳川矿床位于秦岭造山带后陆冲段褶皱带的小秦岭成矿带内,是国内外成矿类型特殊的大规模铀多金属矿床。为了深入了解陕西华阳川铀多金属矿床矿石组成和铀的赋存状态,本文通过采用光学显微镜、扫描电子显微镜、电子探针等现代分析测试方法,对华阳川铀多金属矿床进行了系统的工艺矿物学研究。测试结果显示:(1)主要的铀矿物为贝塔石、晶质铀矿和少量的铀钍石,与长白矿、褐帘石、榍石、磷灰石等相共生。(2)铌钛铀矿多呈自形-半自形粒状结构嵌入在钾长石与方解石内或其裂隙中,粒度主要集中在0. 04mm～0. 64mm,占总量的57. 58%。(3)铀主要以独立铀矿物(贝塔石、晶质铀矿)的形式存在,其中铀赋存于贝塔石与晶质铀矿中,占比分别为78. 20%和15. 02%,其余的铀可能以类质同象或吸附的形式存在。

Ore characteristics and occurrence state of uranium in the Huayangchuan uranium polymetallic deposit, Shaanxi Province

The Huayangchuan deposit is located in the Little Qinling metallogenic belt of the Houluchong fold belt in the Qinling orogenic belt. It is a special large-scale uranium polymetallic deposit in China and elsewhere in the world. The objective of this work is further understanding composition and occurrence of uranium in this deposit. Modern analysis tools have been employed to perform tests on samples, such as optical microscopy, scanning electron microscopy and electron probe. The test results show that (1) the main uranium minerals are betafite, uraninite and a small amount of uranothorite, which are symbiotic with Changbai ore, allanite, titannite and apatite. (2)The betafite is mostly automorphic-hypautomorpuic granular embedded in potassium microcline and calcite or its fissures. The particle size concentrates in 0.04mm~0.64mm, accounting for 57.58% of the total. (3) Uranium mainly exists in the form of independent uranium minerals ( betafite, uraninite), in which uranium is present in the betafite and uraninite, accounting for 78.20% and 15.02%, respectively. The remaining uranium may be present in the form of isomorphism or adsorption.