摘要
为分析某砂岩铀矿酸法地浸试验初期的酸化进程,对与地浸水岩作用密切相关的SO42-、H+、Ca2+、Mg2+、Fe2+和Fe3+等溶质离子运移特征进行了研究。结果表明,下注溶液最快8d抵达抽液孔,40d形成由注液控制的稳定渗流场;H+在水岩作用过程中被部分消耗,其运移羽前沿扩散至抽液孔的时间晚于SO42-离子13d,由H+溶蚀出来的Ca2+、Mg2+则与SO42-同步运移;66d地浸流场实现H+的补给与消耗平衡并形成稳定的浸铀化学场,但需进一步增加注液酸度以达到酸化要求。Fe2+、Fe3+的运移受H+的控制和氧化还原作用的影响,运移与H+基本同步。持续增高的SO42-导致大部分时间内硫酸钙处于过饱和状态,引起浸出液Ca2+浓度和抽液流量的下降。
In order to investigate acidification process during acid leaching test of sandstone uranium ore, the transportation characteristics of solute ions, such as SO42- , H＋ , Caz＋ , Mg2＋ , Fe2＋ and Fe3＋ , which are closely related with water-rock interaction of in-situ uranium leaching, were analyzed. The results show in case of SO42- , it takes 8 days for the earliest leaching solution to reach extraction well, and 40 days to form a stable flow field by leaching solution. Ca2＋ and Mg2＋ move synchronously with SO42- Retarded by water-rock interaction, the forefront of H＋ plume reaches extraction well 13 days later than SO42- , and it takes 66 days to stablish balance between supply and consumption of H＋ , in other words, formation of stable geochemical field for uranium leaching. But a further increase of acidity is still necessary to meet acidification requirements when the stable geochemical field is just built. The transportation process of Fe2＋ and Fe3＋ are controlled by H＋ and affected by oxidation-reduction reaction, resulting in synchronous transportation of Fe2＋ and Fe3＋ with H＋. Gypsum remains saturated most of the time during leaching process due to high concentration of SO42- and Ca2＋ , and chemical blockage caused by gypsum precipitation is also conformed by drop of Ca2＋ concentration and extraction flux.
出处
《有色金属（冶炼部分）》
CAS
北大核心
2015年第6期50-54,共5页
Nonferrous Metals（Extractive Metallurgy)
基金
国家自然科学基金资助项目(40872165)
关键词
砂岩型铀矿
酸法地浸
溶质运移
矿层酸化
sandstone uranium ore
in-situ acid leaching
solute transportation
acidification of ore body
