Journal of MMIJ
Online ISSN : 1884-0450
Print ISSN : 1881-6118
ISSN-L : 1881-6118
大塚 啓司村上 進亮山冨 二郎小出 瑠所 千晴
ジャーナル フリー

2014 年 130 巻 10_11 号 p. 488-493


Acid Mine Drainage (AMD), high acid water containing heavy metals discharged from mines, not only from the operating ones but also from the already abandoned ones, has been recognized as major cause of mine pollution. In Japan, the government spends billions of yen every year to prevent pollution caused by AMD in about 80 abandoned mines. It is widely believed that the treatment will continue for decades or an even century,but it is difficult to predict how long it will be and how much it will cost.Therefore, a predictive model is quite helpful. In our previous work, a two-steps predictive model for solution composition and neutralization chemical requirements of AMD in future was constructed based on the regression analysis and geochemical modeling. The model requires the past historical water quality data from AMD monitoring, such as metal concentration and pH in the solution, instead of the sample rocks as other conventional prediction methods. In this paper, two more case studies were carried out for Japanese abandoned mines. In each case study, future solution composition, neutralizer dosage and sludge generation were estimated. Then, the time when the water quality satisfies Japanese effluent standard was estimated. The results of this study demonstrate the effectiveness of our model for the prediction of AMD quality and chemical requirements of neutralization treatment after mine closing. These results were analyzed in the context of TMR (Total Material Requirement) and the environmental burden of this neutralization process is relatively small comparing to the burden of operations and the long time span of neutralization seems more serious concern. Comparing the result of this paper with that of our previous works, it is revealed that we have to carry out more case studies in order to obtain the general idea of future AMD treatment.

© 2014 The Mining and Materials Processing Institute of Japan
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