摘要
硅化合物广泛存在于铀矿石中,在酸法地浸采铀过程中,部分硅酸盐矿物与硫酸反应形成硅酸。针对酸法地浸采铀过程中硅的迁移及其对生产系统的影响开展了研究。结果显示,硅酸随浸出液进入离子交换吸附系统,其中99%以上又返回到矿层。仅有极少量的硅酸因聚合作用被吸附系统截留,部分附着于树脂表面,部分随溶液流动而进入萃取系统和注液钻孔。硅酸对生产系统的影响主要表现在3个方面:1)聚合度较低的硅酸会在离子交换树脂表面不断聚合,堵塞离子交换树脂的通道,导致离子交换速度和操作容量下降;2)硅酸胶体进入萃取系统会导致三相物生成量增加,严重时可导致乳化;3)硅酸凝胶进入钻孔会导致钻孔堵塞。总的来说,硅大量溶出会导致设备紧张、成本上升、生产能力下降等一系列问题。为降低硅对生产系统的影响,可使用氢氧化钠进行树脂脱硅,以恢复其离子交换性能,使用氢氧化钠+空压机洗井恢复钻孔过液能力。
Silicon compounds are widely found in uranium ore.Part of silicate mineral reacts with sulfuric acid to form silicic acid in in-situ leaching of uranium by acid.Migration of silicon and its influence on production system in in-situ leaching of uranium by acid method was carried out.The results show that silicic acid enters ion exchange adsorption system with leachate,and more than 99% of it returns to ore bed.Only a very small amount of silicic acid is trapped by adsorption system due to polymerization,part of it is attached to surface of resin,and part of solution flows into extraction system and injection hole.Impact of silicic acid on production system is mainly manifested in three aspects.1)Silicic acid with a low degree of polymerization will continuously polymerize on surface of ion exchange resin,blocking channel of ion exchange resin,resulting in drop of ion exchange speed and operating capacity.2)Entry of silicic acid colloid into extraction system will lead to an increase in production of three phases,which can lead to emulsification in severe cases.3)Silicic acid gel entering borehole will cause borehole to be blocked.In general,massive dissolution of silicon will cause a series of problems such as equipment strain,cost raise,and decrease of production capacity.In order to reduce impact of silicon on production system,sodium hydroxide can be used for resin desiliconization to restore its ion exchange performance,and sodium hydroxide+air compressor can be used to wash well to restore the ability of drilling fluid.
作者
胡鹏飞
邢拥国
刘金辉
HU Peng-fei;XING Yong-guo;LIU Jin-hui(Inner Mongolia Mining Co.,Ltd.,CNNC,Huhhot,010010,China;School of Water Resources Environmental Engineering,East China University of Technology,Nanchang 330013,China;China Nuclear Mining Technology Group Co.,Ltd.,Beijing 101149,China)
出处
《有色金属（冶炼部分）》
CAS
北大核心
2021年第8期56-64,共9页
Nonferrous Metals（Extractive Metallurgy)
基金
国家国防科技工业局核能开发项目(科工计[2012]1523号)
国家自然科学基金核技术创新联合基金资助项目(U1967209)
中核集团公司科技重大专项(中核科发[2012]181号)。
关键词
硅酸
地浸采铀
离子交换
萃取
钻孔堵塞
silicic acid
in-situ leaching of uranium
ion exchange
extraction
borehole blockage
