某砂岩铀矿床不同岩性铀矿石浸出性能研究

Study on leaching behavior of different uranium ores from a sandstone uranium deposit

某矿床发育有砂岩和泥质砂岩2种类型铀矿体,铀资源主要存在于泥质砂岩型铀矿体中。工艺矿物学和室内酸法搅拌浸出试验结果表明:原矿铀品位与黏土矿物含量呈正比,以蒙脱石为主的黏土矿物既是铀富集的重要吸附剂,也是导致矿石渗透性较低的主要因素;在液固体积质量比为5L/kg,硫酸质量浓度≥5g/L条件下,砂岩铀矿石和泥质砂岩铀矿石的浸出性能均较好,其四价铀和六价铀均能达到较好的浸出效果,总铀浸出率均可达75%以上。

There are two kinds of uranium ores in a sandstone uranium deposit, which are sandstone type and clayey sandstone type uranium ores, and uranium resources are mainly found in the clayey sandstone type uranium ores. The results of technological mineralogy study show that the content of initial uranium and the percentage of U^6＋ in total uranium are growing with the increase of clay content. Smectite is the dominant component of clay mineral which are not only an important adsorbent for uranium enrichment, but also the main factor which lead to the low permeability. The results of the acid agitation leaching experiments show that the leaching rate is over 75% when liquid-to-solid ratio is 5 L/kg, and sulfuric acid concentration is above 5 g/L. Through in-depth analysis of the lea- ching behavior of U^8＋ and U^4＋ , U^8＋ and U^4＋ all are easily leached out in the leaching process with good effects of the leaching rate.