Improvement in pH and Total Iron Concentration of Acid Mine Drainage after Backfilling: A Case Study of an Underground Abandoned Mine in Japan
If the excavated underground veins are not backfilled, they may be a factor in the continued outflow of acid mine drainage (AMD). The flow rate of AMD can be reduced by backfilling underground drifts from abandoned mines. In addition, the quality of AMD may be improved as the flow rate of AMD reduce...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-11-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/11/11/1297 |
| _version_ | 1797509266969460736 |
|---|---|
| author | Kohei Yamaguchi Shingo Tomiyama Toshifumi Igarashi Saburo Yamagata Masanori Ebato Masatoshi Sakoda |
| author_facet | Kohei Yamaguchi Shingo Tomiyama Toshifumi Igarashi Saburo Yamagata Masanori Ebato Masatoshi Sakoda |
| author_sort | Kohei Yamaguchi |
| collection | DOAJ |
| description | If the excavated underground veins are not backfilled, they may be a factor in the continued outflow of acid mine drainage (AMD). The flow rate of AMD can be reduced by backfilling underground drifts from abandoned mines. In addition, the quality of AMD may be improved as the flow rate of AMD reduces. In this paper, the quality of the AMD after backfilling was evaluated by a three-dimensional geochemical analysis model when the groundwater level was recovered after backfilling. The measured dissolved iron (Fe) and sulfate ion (SO<sub>4</sub><sup>2−</sup>) concentrations and pH before backfilling the drift were reproduced by the calibration of the simulation. Using the calibrated model, the pH at the outlet of the drift was changed from about pH 3 before backfilling to about pH 4 to 5 after backfilling. When calcite was contained in the filling materials of the drift, the pH approached neutral. However, when gypsum was formed, the neutralization was inhibited. The Fe concentration discharged from the drift was calculated at approximately 0.002 mol/L before backfilling. The total Fe concentration was calculated at 0.0004 mol/L or less after backfilling, and the dissolved Fe concentration decreased by several orders of magnitude after backfilling. A geochemical model quantitatively evaluated the improvement in water quality after backfilling the drifts. This method can be applied to the other abandoned mines with similar hydrogeological conditions. |
| first_indexed | 2024-03-10T05:15:17Z |
| format | Article |
| id | doaj.art-ed4fb8f8063a4e579ddc0e715ebdf2ee |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T05:15:17Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-ed4fb8f8063a4e579ddc0e715ebdf2ee2023-11-23T00:33:15ZengMDPI AGMinerals2075-163X2021-11-011111129710.3390/min11111297Improvement in pH and Total Iron Concentration of Acid Mine Drainage after Backfilling: A Case Study of an Underground Abandoned Mine in JapanKohei Yamaguchi0Shingo Tomiyama1Toshifumi Igarashi2Saburo Yamagata3Masanori Ebato4Masatoshi Sakoda5Division of Sustainable Resources Engineering, Graduate School of Engineering, Hokkaido University, Sapporo 060-8628, JapanFaculty of Engineering, Hokkaido University, Sapporo 060-8628, JapanFaculty of Engineering, Hokkaido University, Sapporo 060-8628, JapanMitsubishi Materials Corporation, 3-2-3, Marunouchi, Chiyoda-ku, Tokyo 100-8117, JapanOyo Corporation, 2-10-9, Daitakubo, Minami-ku, Saitama-shi, Saitama 336-0015, JapanJapan Oil, Gas and Metals National Corporation (JOGMEC), 2-10-1, Toranomon, Minato-ku, Tokyo 105-0001, JapanIf the excavated underground veins are not backfilled, they may be a factor in the continued outflow of acid mine drainage (AMD). The flow rate of AMD can be reduced by backfilling underground drifts from abandoned mines. In addition, the quality of AMD may be improved as the flow rate of AMD reduces. In this paper, the quality of the AMD after backfilling was evaluated by a three-dimensional geochemical analysis model when the groundwater level was recovered after backfilling. The measured dissolved iron (Fe) and sulfate ion (SO<sub>4</sub><sup>2−</sup>) concentrations and pH before backfilling the drift were reproduced by the calibration of the simulation. Using the calibrated model, the pH at the outlet of the drift was changed from about pH 3 before backfilling to about pH 4 to 5 after backfilling. When calcite was contained in the filling materials of the drift, the pH approached neutral. However, when gypsum was formed, the neutralization was inhibited. The Fe concentration discharged from the drift was calculated at approximately 0.002 mol/L before backfilling. The total Fe concentration was calculated at 0.0004 mol/L or less after backfilling, and the dissolved Fe concentration decreased by several orders of magnitude after backfilling. A geochemical model quantitatively evaluated the improvement in water quality after backfilling the drifts. This method can be applied to the other abandoned mines with similar hydrogeological conditions.https://www.mdpi.com/2075-163X/11/11/1297AMDbackfillinggeochemical analysispyritedissolved oxygen |
| spellingShingle | Kohei Yamaguchi Shingo Tomiyama Toshifumi Igarashi Saburo Yamagata Masanori Ebato Masatoshi Sakoda Improvement in pH and Total Iron Concentration of Acid Mine Drainage after Backfilling: A Case Study of an Underground Abandoned Mine in Japan Minerals AMD backfilling geochemical analysis pyrite dissolved oxygen |
| title | Improvement in pH and Total Iron Concentration of Acid Mine Drainage after Backfilling: A Case Study of an Underground Abandoned Mine in Japan |
| title_full | Improvement in pH and Total Iron Concentration of Acid Mine Drainage after Backfilling: A Case Study of an Underground Abandoned Mine in Japan |
| title_fullStr | Improvement in pH and Total Iron Concentration of Acid Mine Drainage after Backfilling: A Case Study of an Underground Abandoned Mine in Japan |
| title_full_unstemmed | Improvement in pH and Total Iron Concentration of Acid Mine Drainage after Backfilling: A Case Study of an Underground Abandoned Mine in Japan |
| title_short | Improvement in pH and Total Iron Concentration of Acid Mine Drainage after Backfilling: A Case Study of an Underground Abandoned Mine in Japan |
| title_sort | improvement in ph and total iron concentration of acid mine drainage after backfilling a case study of an underground abandoned mine in japan |
| topic | AMD backfilling geochemical analysis pyrite dissolved oxygen |
| url | https://www.mdpi.com/2075-163X/11/11/1297 |
| work_keys_str_mv | AT koheiyamaguchi improvementinphandtotalironconcentrationofacidminedrainageafterbackfillingacasestudyofanundergroundabandonedmineinjapan AT shingotomiyama improvementinphandtotalironconcentrationofacidminedrainageafterbackfillingacasestudyofanundergroundabandonedmineinjapan AT toshifumiigarashi improvementinphandtotalironconcentrationofacidminedrainageafterbackfillingacasestudyofanundergroundabandonedmineinjapan AT saburoyamagata improvementinphandtotalironconcentrationofacidminedrainageafterbackfillingacasestudyofanundergroundabandonedmineinjapan AT masanoriebato improvementinphandtotalironconcentrationofacidminedrainageafterbackfillingacasestudyofanundergroundabandonedmineinjapan AT masatoshisakoda improvementinphandtotalironconcentrationofacidminedrainageafterbackfillingacasestudyofanundergroundabandonedmineinjapan |