华北隐伏型煤矿主要充水含水层水化学组分来源及演化机制分析

Analysis on the sources and evolution mechanisms of hydro-chemical components in major water-filled aquifers of concealed coal mines in North China

为了确定华北型煤矿区主要充水含水层水化学组分的主要来源及演化机制,以平顶山矿区为研究对象。基于平顶山矿区内285个水样常规离子(K^(+)+Na^(+)、Ca^(2+)、Mg^(2+)、Cl^(-)、SO_(4)^(2-)、HCO_(3)^(-)、CO_(3)^(2-))、pH及TDS等数据,利用Gibbs图分析其主要控制因素、Piper图分析其主要水化学类型、离子组合比及主成分分析揭示其水化学组分的主要来源及演化机制。结果表明:寒灰水主要水化学类型为HCO_(3)^(-)Ca·Mg及HCO_(3)·SO_(4)-Ca·Na·Mg型,其中HCO_(3)^(-)、Ca^(2+)、Mg^(2+)、SO_(4)^(2-)主要来自碳酸盐岩(白云石)、硫酸盐岩(石膏)的溶解,Na^(+)主要来自岩石中,这是Ca^(2+)-Na^(+)、Mg^(2+)-Na^(+)的负交替吸附作用;七灰水主要水化学类型为HCO_(3)^(-)Ca及HCO_(3)·SO_(4)-Na·Ca·Mg型,其中HCO_(3)^(-)、Ca^(2+)、Mg^(2+)主要来自碳酸盐岩(方解石)的溶解,SO_(4)^(2-)来自黄铁矿的氧化作用;砂岩水的主要水化学类型为HCO_(3)^(-)Na型,其中HCO_(3)^(-)、Na^(+)主要来自硅酸盐岩的溶解;二灰水主要水化学类型为HCO_(3)^(-)Ca及HCO_(3)·SO_(4)-Na·Ca·Mg型,也有部分HCO_(3)^(-)Na型,其中HCO_(3)^(-)、Ca^(2+)、Mg^(2+)和SO_(4)^(2-)的来源与七灰水的来源相同,Na^(+)含量高是由于砂岩水的混和作用。此外采煤扰动作用导致研究区地下水径流条件发生改变,影响了水化学组分的来源及演化机制,这对以后矿井防治水有深远影响。

In order to determine the main source and evolution mechanism of the hydro-chemical components of the main water filling aquifer in the North China type coal mine area,Pingding mountain mining area is taken as the research object.Based on the data such as conventional ions(K^(+)+Na^(+)、Ca^(2+)、Mg^(2+)、Cl^(-)、SO_(4)^(2-)、HCO_(3)^(-)、CO_(3)^(2-)),pH and TDS of 285 water samples in Pingdingshan mining area,Gibbs diagram was used to analyze the main controlling factors,Piper diagram was used to analyze the main hydro-chemical types,the ion combination ratio and principal component analysis was used to reveal the main source and evolution mechanism of the hydro-chemical components.The results show that the main hydro-chemical types of cambrian limestone groundwater are HCO_(3)-Ca·Mg and HCO_(3)·SO_(4)-Ca·Na·Mg,the HCO_(3)^(-)、Ca^(2+)、Mg^(2+)、SO_(4)^(2+)mainly derived from the dissolution of carbonate rocks(dolomite)and sulfate rocks(gypsum),and Na+mainly derived from rocks,which is the negative alternating adsorption of Ca^(2+)-Na^(2+)、Mg^(2+)-Na^(+);The main hydro-chemical types of groundwater in the seventh limestone aquifer of Taiyuan Formation are HCO_(3)-Ca and HCO_(3)·SO_(4)-Na·Ca·Mg.The HCO_(3)^(-)、Ca^(2+)、Mg^(2+)mainly come from the dissolution of carbonate rocks(calcite),and SO_(4)^(2-)derived from the oxidation of pyrite;The main hydro-chemical type of sandstone water is HCO_(3)-Na,in which HCO_(3)、Na^(+)mainly derived from the dissolution of silicate minerals;The main hydro-chemical types of groundwater in the second limestone aquifer of Taiyuan Formation are HCO_(3)^(-)、Ca^(2+)、HCO_(3)^(-)·SO_(4)-Na·Ca·Mg and some HCO,-Na.The sources of HCO_(3)^(-)、Ca^(2+)、Mg^(2+)、SO_(4)^(2-)are consistent with of groundwater in the seventh limestone aquifer of Taiyuan Formation.The high concentration of Na^(+)is due to the mixing of sandstone water.In addition,the disturbance of coal mining results in the change of groundwater runoff conditions in the study area,which affects the origin and evolution mechnism of hydro-chemical components.This will have a far-reaching impact on mine water control in the future.