中关铁矿地下水水化学特征简析

Brief analysis of hydro-chemical characteristics of groundwater in Zhongguan iron mine

为了使中关铁矿的开采过程能够顺利进行,明确研究区地下水水化学特征及水力联系状况是非常重要的一环。选取研究区2021年39个地下水水样(分别于-170 m、-230 m、-245 m这3个水平工作面取样)进行水质检测,运用统计分析、Piper三线图等方法对研究区地下水水化学特征及成因进行分析。结果表明:由-170水平至-245水平,随采样深度的增加SO_(4)^(2-)浓度和TDS质变逐渐递增,随SO_(4)^(2-)离子浓度的增加HCO_(3)-的浓度逐渐减小,水化学类型由上至下从Ca·Mg-HCO_(3)向Mg·Ca-SO_(4)·HCO_(3)和Ca·Mg-SO_(4)演化。分析结果说明有部分区域奥陶系灰岩水从帷幕底部进入帷幕内,并与围岩发生了离子交换,因底部蚀变闪长岩基底为相对隔水层,所以该部分水流经闪长岩蚀变带,从帷幕外侧绕过帷幕体底部流经闪长岩蚀变带进入帷幕内侧。

In order to make the mining process of Zhongguan iron mine proceed smoothly,it is very important to clarify the water chemical characteristics and hydraulic relations of groundwater in the study area.Thirty-nine groundwater samples in 2021(sampled from three horizontal working faces of-170 m,-230 m and-245 m respectively)in the study area were selected for water quality testing.Statistical analysis and piper three-line diagram were used to analyze the chemical characteristics and causes of groundwater in the study area.The results show that:From-170 level to-245 level,the concentration of SO_(4)^(2-)and the qualitative change of TDS gradually increased with the increase of sampling depth,and the concentration of HCO_(3)^(-)gradually decreased with the increase of the concentration of SO_(4)^(2-)ions.The hydro-chemical type evolved from Ca·Mg-HCO_(3)to Mg·Ca-SO_(4)·HCO,and Ca·Mg-SO_(4)from top to bottom.The analysis results show that:In some areas,the Ordovician limestone water enters into the curtain from the bottom and has ion exchange with the surrounding rock.Because the base of the altered diorite at the bottom is a relative water-proof layer,the water flows through the diorite alteration zone and enters the inner part of the curtain from the outside of the curtain,by-products the bottom of the curtain body and flows through the diorite alteration zone.