铜陵硫铁矿基地集中开采区水文地球化学特征

铜陵是我国重要的硫铁矿基地,矿业活动对周边环境造成了较大的影响。本文对研究区的地下水环境综合指标进行了计算,利用piper三线图对地下水化学类型进行了划分,通过离子比例系数、相关性、三种矿物水溶液的饱和指数计算方法分析了地下水化学成分的形成过程,并对研究区的地下水进行了重金属污染分析。结果表明:研究区地下水普遍呈弱碱性,为淡水、软水;全区地下水化学类型主要为HCO_3-Ca型;地下水化学成分主要来源于碳酸盐岩溶解,伴有硅酸盐的溶解; Ca~(2+)、Mg~(2+)多来自阳离子交换作用; SO_4~(2-)多来自硫化物氧化,与矿业活动密切相关;地下水离子的控制因素主要为岩石风化作用;方解石相对水溶液大多处于过饱和状态,白云石和石膏相对水溶液处于非饱和状态;重金属对地下水的影响区域较小,影响区主要分布于钟鸣硫铁矿一带。

Hydrogeochemical Characteristics of Concentrated Mining Areas in the Tongling Pyritic Base

Tongling is an important pyrite base in China, and mining activities in the area have a great impact on the surrounding environment. In this paper, the comprehensive index of the groundwater environment of the study area was calculated and the heavy metal pollution in the groundwater of the study area was analyzed, using piper trilinear diagram to determine the groundwater chemical type, using methods of ion ratios, correlations and saturation indexes of three kinds of mineral water solution for analysis of the formation of chemical compositions of the groundwater. The results showed that the groundwater in the study area was weakly alkaline, fresh and soft. The main chemical type of the groundwater in the region was the HCO₃-Ca type. The chemical compositions of the groundwater mainly came from the dissolution of carbonate rocks, and accompanied by the dissolution of silicates. Ca²⁺ and Mg²⁺ came mostly from cation exchanges. SO^2-₄ related closely to the mining activity mostly came from the oxidation of sulfides. The main controlling factor of ions in the groundwater was the rock weathering. The groundwater was mostly supersaturated to calcite and unsaturated to dolomite and gypsum. The areas of groundwater influenced by heavy metals were small, distributed mainly in the Zhongming pyrite area.