澳大利亚兰杰一号铀矿之生命周期：地质、资源、生产与修复

The life of Ranger 1 uranium mine in Australia:Geology, resources, production and rehabilitation

兰杰一号铀矿及其所属的鳄鱼河铀矿田产于北澳太古宙克拉通内古元古代裂谷背景下发展起来的松溪造山带,矿体产于新太古代-古元古代结晶-变质基底/晚古元古代-中元古代康博尔吉红层建造不整合界面之下,铀矿化分3个时代,U1为1720~1680Ma,U2为1420~1040Ma,U3为474±6Ma,U1是主矿化时代。该矿床于1969年后期通过航空放射性测量被发现,1970’s经勘探圈定了No.1和No.3两个铀矿体,总计资源储量124681t@0.23%U3O8。1980年10月正式露采,至2018年12月,总计生产了128739t U3O8。1985财年开始,ERA(澳大利亚能源资源有限责任公司)向世界核能市场共计销售了产于兰杰铀矿的119882t U3O8。2009年,发现了No.3深部矿,探明资源储量为43857t@0.22%U3O8,这部分资源将以地下开采方式利用。预计到2026年,采区地貌景观和生态环境将得到恢复。进一步讨论了澳北元古宙不整合面型铀矿找矿的方向,持续稳定的铀矿开采与生产的意义,以及投资澳大利亚铀矿业需要注意的政治与法律问题。这些内容可以为国内矿业企业及地勘单位合理部署澳洲铀矿勘查与开发提供参考。

The tectonic setting of Ranger uranium deposit, also ARUF, is Pine Creek orogen, which was developed from the Paleoproterozoic rift in the Archean craton of North Australia. The orebodies lie under the interface between the NeoarchaeanPaleoproterozoic crystallization-metamorphic basement and Late Paleo-Mesoproterozoic Kombolgie red bed formations. There are three epochs of uranium mineralization, which are U1:1720~1680 Ma, U2:1420~1040 Ma and U3:474 ± 6 Ma. U1 is the main mineralization epoch.The deposit was discovered by aerial radioactivity survey in late 1969. No. 1 and No. 3 orebodies were delineated by exploration in the 1970’s, with a total resource of 124681 t@0.23% U3O8. From October 1980 to December 2018, a total of 128739 t U3O8 was produced by open-pit mining. Since fiscal year 1985, ERA has sold 119882 t U3 O8 from Ranger uranium mine to the nuclear energy market in the world. In 2009, No. 3 deep orebody was discovered, with reserves of 43857 t@0.22% U3O8,which will be exploited by underground mining. It is expected that the geomorphological landscape and ecological environment of the mining area will be restored by 2026.This paper further discusses the prospecting direction of Proterozoic unconformity uranium deposits in northern Australia, the significance of sustained and stable uranium mining and production, and the political and legal issues that need attention in investing in Australian uranium mining. These contents can provide references for China’s mining enterprises and geological exploration units to rationally deploy Australian uranium exploration and development.