海底金矿矿坑涌水水源判识及演化研究

RECHARGE SOURCE IDENTIFICATION AND EVOLUTION OF INFLOWING WATER IN A SEABED GOLD MINE

为查明新立海底金矿浅部裂隙涌水在开采条件下的演化规律,从水文地球化学的角度出发,提出采用主成分分析法和最大似然概率法对裂隙涌水水源及其混合比进行判识和计算,并采用数值模拟法间接验证计算结果的可靠性。研究表明:该方法能够有效识别矿山涌水水端元的组合模型及其变化,计算出可能性最大的端元混合比;新立金矿浅部裂隙涌水端元模型经历了由Ⅰ类基岩水+海底地下水到Ⅰ类基岩水+海底地下水+现代海水的演化过程;海底地下水和现代海水易从采空区两侧肩部进入矿坑,且涌水中海水含量呈现先增加后减小的变化规律。

This paper aims to capture the evolution rules of fracture-inflowing water at the shallow depth of Xinli gold deposit exploited under seawater. From a hydrogeochemical point of view,it uses the principal component analysis and maximum likelihood method to identify the water-recharging sources of the inflowing water and estimate their mixing ratios. Using numerical modeling,the paper verifies indirectly the inflowing water evolutionary character and calculates it with the proposed method. The research shows that the method can effectively identify the combined patterns and variations of end-members of mine inflowing water,and calculate the most possible mixing ratios. The end-member model of the fracture-inflowing water of the Xinli gold mine has been changed from the typeⅠbedrock saline water＋ seabottom groundwater to the type Ⅰ bedrock saline water ＋ seabottom groundwater ＋ seawater. The sea bottom groundwater and seawater are prone to percolating into the mine pit from the shoulders of its both sides. The seawater percentage of the mine inflowing water goes through an increasing first and decreasing history.