准噶尔盆地南缘硫磺沟地区中侏罗统头屯河组铀的赋存状态研究

Study on the Occurrence State of Uranium in the Toutunhe Formation of Middle Jurassic in Liuhuanggou Region,Southern Margin of Junggar Basin

准噶尔盆地南缘硫磺沟铀矿是近年来“煤铀兼探”发现的砂岩型铀矿床。详细研究该矿铀的赋存状态,对其矿床成因认识及选冶开采均具有重要的意义。通过扫描电镜、α径迹蚀刻、逐级化学提取等方法,对该区重要含矿层头屯河组发育的铀的赋存状态进行了研究。结果发现,铀主要以铀矿物产出,主要是沥青铀矿,另外存在少量钛铀矿和含U、Si、P、Y等元素的未知铀矿物;其次呈吸附态产出。这些铀矿物多呈不规则状、胶状、肾状、葡萄状和超显微状,分布在粘土矿物、黄铁矿及有机质中。逐级化学提取分析发现,各形态铀的含量不均一,其中主要为残渣态,平均为87.71%;其次为弱酸提取态和可氧化态,分别平均占6.51%和5.09%。综上所述,硫磺沟地区头屯河组铀的赋存状态主要为铀矿物和吸附态两种形式。含U、Si、P、Y等元素的未知铀矿物还需进一步研究,可能有发现新矿物的可能。

The Liuhuanggou uranium deposit in the southern margin of Junggar basin is a sandstone-type uranium deposit discovered in the coal-uranium exploration in recent years.Study on the occurrence state of uranium is of great significance for understanding the genesis and the mining of the deposit.The occurrence state of uranium developed in Toutunhe formation,an important ore-bearing layer in this area,was studied by scanning electron microscopy,alpha track etching,and sequential extraction.The results showed that uranium was mainly produced by uranium minerals,followed by adsorption state.The uranium minerals are mainly pitchblende,and there are a small amount of ilmenite and unknown uranium minerals containing U,Si,P,Y and other elements.These uranium minerals are mostly irregular,colloidal,kidney-like,grape-like and ultra-microscopic,and are distributed in clay minerals,pyrite and organic matter.The result of sequential extraction analysis found that the content of uranium in each phase behavior was uneven,the main was in residual,with an average of 87.71%;the second were weak acid extractable and oxidizable,accounting for 6.51%and 5.09%respectively.In summary,the occurrence of uranium in the Toutunhe formation in the Liuhuanggou region is mainly in the forms of uranium minerals and adsorption.Unknown uranium minerals containing U,Si,P,Y and other elements need further study,which may be possible to find new minerals.