基于GIS的离子型稀土堆浸尾矿区稀土和浸取剂分布规律研究

发布时间：2018-03-03 05:00

本文选题：堆浸尾矿　切入点：形态分析　出处：《江西理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：堆浸技术以其投资少、工艺简单、管理简单及见效快等特点在风化壳淋积型稀土早期开采中受到重视,但浸矿后堆积如山的矿渣释放出的稀土元素及浸取剂等污染物改变原土壤的特性,影响生态环境。本论文以江西赣州市赣县风化壳淋积型稀土堆浸尾矿为研究区域,采用地统计分析方法研究土壤中稀土、稀土形态、残留浸取剂及其次生物含量和分布空间变异性,并通过克里金法(Kriging)进行空间含量插值。研究结果表明:(1)尾矿中La元素的变异强度最大,变异系数为170%,其他稀土含量变异系数属于中等变异强度。尾矿中稀土元素含量的均值来看,存在很大差异,Tb的含量为3.49mg/kg,而Nd、Eu和Dy分别为1479.22 mg/kg,3642.81 mg/kg,1919.56 mg/kg。插值结果显示,尾矿中La元素含量由北到南成阶梯状逐渐减少,而Eu元素的分布情况由北到南逐渐增加,其余稀土元素分布情况大致相似,由西北方位到东南方位逐渐增加。尾矿东南方位矿渣中稀土含量高,可进行二次开采,其他含量低的矿渣可用于建材或催化剂研制等行业。(2)尾矿中可交换态稀土元素大量富集于南面,是由于稀土可交换态具有较强的活性,容易溶解到雨水中,因雨水的冲刷,稀土元素被带到地势低的地方;稀土碳酸盐结合态含量分布相对均匀,并未出现明显的局部含量突出的现象;稀土铁锰氧化物结合态在西北方位含量相对较低,在尾矿的东面含量相对富集;对于稀土有机物结合态含量分布并没有明显的分布趋势,尾矿的东南方位比其他区域的含量相对小,同时局部有明显的稀土富集;稀土残渣态含量由西到东逐渐增加。尾矿中稀土元素容易被释放出来,被植物吸收利用,对植物的生长危害大,同时也危害周边的生态环境。(3)尾矿土壤p H值在3.75~5.57之间,呈现极强酸性或强酸性,有机质的含量最小值只有2.50 mg/kg,最大值为32.76 mg/kg,总体属于极缺等级;尾矿中p H值与铵态氮、硝态氮之间呈现负相关;通过对尾矿中残留浸取剂及其次生物数据进行空间含量分布模拟,尾矿中铵态氮含量基本在3.0~7.0 mg/kg之间,含量变化比较稳定;对比铵态氮与硝态氮空间分布图,铵态氮含量低的位置反而硝态氮含量高;硫酸根含量在西北方位比较低,而西南-东南方位含量比较高。矿区植被恢复建议构建以豆类植物、马尾松、蕨类植物等为主的群落。
[Abstract]:Heap leaching technology has been paid attention to in the early mining of weathered crust leaching rare earths because of its characteristics of low investment, simple process, simple management and quick effect. However, the rare earth elements and extractant released from the heap slag after leaching change the characteristics of the original soil and affect the ecological environment. In this paper, the tailings of weathered crust leaching type rare earth in Ganxian County, Ganzhou City, Jiangxi Province, are taken as the research area. The methods of geostatistical analysis were used to study the spatial variability of rare earths, forms of rare earths, residual extractants and their secondary biological contents in soils. The results show that the variation intensity of La element in the tailings is the largest. The coefficient of variation is 170, and the coefficient of variation of other rare earth contents is of moderate variation intensity. There is a significant difference in the average content of rare earth elements in tailings between 3.49 mg / kg, and 1479.22 mg / kg ~ (-1) mg / kg ~ (-1) mg 路kg ~ (-1) 路kg ~ (-1) 路kg ~ (19. 56) mg 路kg ~ (-1) 路kg ~ (-1) of Ndnau EU and D _ y, respectively. The content of La in tailings decreases gradually from north to south, while the distribution of EU increases from north to south, and the distribution of other rare earth elements is similar. From the northwest to the southeast, the tailings have a high content of rare earths in the southeastern tailings, which can be used for secondary mining. Other low-content slag can be used in industries such as building materials or catalyst development, etc.) the exchangeable rare earth elements in tailings are enriched in large quantities in the south, because the exchangeable rare earths have strong activity and are easily dissolved in Rain Water and washed by Rain Water. The rare earth elements are brought to the low terrain; the content of rare earth carbonate binding state is relatively uniform, but there is no obvious local content prominent phenomenon; the content of rare earth iron and manganese oxide bound state is relatively low in the northwest, On the east side of the tailings, there is no obvious distribution trend of the bound content of rare earth organics, the southeast orientation of the tailings is smaller than that of other regions, and there is obvious rare earth enrichment in the parts of the tailings. The content of rare earth residue gradually increases from west to east. The rare earth elements in tailings are easy to be released, absorbed by plants, and harmful to the growth of plants. At the same time, they also endanger the surrounding ecological environment. The pH value of tailings soil is between 3.75 and 5.57. The content of organic matter was only 2.50 mg / kg and the maximum value was 32.76 mg / kg. Through the spatial distribution simulation of residual leaching agent and its secondary biological data in tailings, it is found that the content of ammonium nitrogen in tailings is between 3.0 mg/kg and 7.0 mg/kg, and the change of content is relatively stable, and the spatial distribution of ammonium nitrogen and nitrate nitrogen is compared. On the contrary, the nitrate content was higher in the lower ammonium content, lower sulfate content in the northwest and higher in the southwest and southeast. The vegetation restoration in the mining area suggested the establishment of legume, Masson pine and pteridophyte communities.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD955

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