摘要
赣南离子型稀土浸矿开采过程中,因大量使用(NH_4)_2SO_4作浸矿剂造成土壤氮化物累积,引发矿区土壤及水体氮化物的持续严重污染。通过模拟土柱实验,测定原矿土壤(未开采的稀土矿土壤)和一般土壤(矿山周边的普通土壤)在模拟浸矿过程中氮化物的污染含量,研究氮化物在土柱实验中的迁移特征及规律。结果表明:浸矿过程中,原矿土壤和一般土壤中氮化物主要以铵态氮形式存在,说明铵态氮是导致稀土矿区土壤污染和水环境污染的主要原因;同时由于土壤的固氮作用、淋滤过程中铵态氮向下迁移及减少的共同作用,致使试验中原矿土壤和一般土壤铵态氮含量总体随天数表现为降低、升高、再降低趋势;并且与一般土壤相比,原矿土壤中稀土离子和NH^+_4会发生交换解析作用增加原矿土壤的固氮作用,同时稀土的存在会增加土壤本身对氮化物的吸附能力。研究结论为赣南离子型稀土矿浸矿过程中氮化物的迁移规律提供基础依据。
Because of using large amounts of ammonium sulfate as a leaching agent during mining of South China ion-adsorption rare earth ore,soil and water were polluted seriously. By simulating soil column experiment,the nitride pollutants content,characteristics and regularity of nitride compounds in the soil column migration were determined. The results showed that the ore in soil and soil nitride mainly existed in the form of ammonium nitride and ammonium nitride loss was the main cause of water pollution in mining area and the surrounding soil. With test ore and general soil ammonium nitride content in the overall performance with a number of days to reduce,higher and lower reciprocating,the reason was that the soil nitride fixation and leaching ammonium nitride processed downward migration to reduce the result of joint action. Ores were compared with general soil,the soil ores of rare earth ions in the soil and NH＋_4exchange,parsing happened to increase ore soil nitride fixation,and the existence of the rare earth could increase the soil nitride adsorption capacity.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2016年第3期363-372,共10页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金项目(51464014)资助
关键词
离子型稀土矿
氮化物
土柱试验
迁移规律
ionic type rare-earth ore
nitride
soil column experiment
migration patterns
