Presented paper

IMWA2019 Students work

Hydrochemical Characteristics Analysis and Water Source Recognition for the Mixed Mine Water: A Case Study of the Jinggezhuang Mining Area

Dong, Donglin (1); Lin, Gang (2); Gao, Yixuan (3); Zhang, Yiyan (4)
1: China University of Mining and Technology; 2: China University of Mining and Technology; 3: China University of Mining and Technology; 4: China University of Mining and Technology

Hydrochemical analysis is one of the most efficient and simple methods to distinguish the source of mine water inrush. However, in reality, its applicability has been restricted hugely due to the mine water inrush source are usually the mixed one.

In this study, taking Jinggezhuang mining area as an example, the hydrochemical characteristics of the mixed mine water (the mixture of the ordovician limestone water, k6-coal 12, coal 9-coal 7, coal 5 roof sandstone water and the alluvial loose aquifer at a ratio of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 and 9:1, respectively) were firstly investigated by the water quality test; secondly, the mixed reaction mechanism was rapidly obtained using the irreversible reaction simulation model of PHREEQC, and also established a water mixed reaction model applied for Jinggezhuang mining area by the error analysis of hydrochemical compositions of water bursting point and the standard values.

The result indicates that the concentrations of main ions in the mixed water all showed an increase tendency with continuously extend of ordovician limestone water. The variation of Na+, SO42-, HCO3- is smoother, K++Na+ increased from 12.5 mg/L to 20.5 mg/L, SO42- is extended from 17.9 mg/L to 37.9 mg/L, and HCO3- shifted from 155.7 mg/L to 200.6 mg/L. In addition, Total Dissolved Solids (TDS) and the mineralization is also gradually increasing with a large percentage of ordovician limestone water, whereas the total hardness and PH getting smaller.

By discriminant analysis of the 4 unknown water points, the recognition precision of the model is up to more than 90%, it is expected to provide a scientific basis for the rapid identification of mine water inrush sources.