Recovery of calcium carbonate from steelmaking slag and utilization for acid mine drainage pre-treatment

2012 ◽  
Vol 65 (12) ◽  
pp. 2236-2241 ◽  
Author(s):  
J. Mulopo ◽  
M. Mashego ◽  
J. N. Zvimba
Keyword(s):  
Calcium Carbonate ◽  
Hydrochloric Acid ◽  
Acid Mine Drainage ◽  
Flow Rate ◽  
Mine Drainage ◽  
Steelmaking Slag ◽  
Carbonation Reaction ◽  
Acid Mine ◽  
Pre Treatment ◽  
Co2 Flow

The conversion of steelmaking slag (a waste product of the steelmaking process) to calcium carbonate (CaCO3) was tested using hydrochloric acid, ammonium hydroxide and carbon dioxide via a pH-swing process. Batch reactors were used to assess the technical feasibility of calcium carbonate recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effects of key process parameters, such as the amount of acid (HCl/calcium molar ratio), the pH and the CO2 flow rate were considered. It was observed that calcium extraction from steelmaking slag significantly increased with an increase in the amount of hydrochloric acid. The CO2 flow rate also had a positive effect on the carbonation reaction rate but did not affect the morphology of the calcium carbonate produced for values less than 2 L/min. The CaCO3 recovered from the bench scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with the commercial laboratory grade CaCO3.

Regeneration of barium carbonate from barium sulphide in a pilot-scale bubbling column reactor and utilization for acid mine drainage

2012 ◽  
Vol 65 (2) ◽  
pp. 324-331 ◽  
Author(s):  
J. Mulopo ◽  
J. N. Zvimba ◽  
H. Swanepoel ◽  
L. T. Bologo ◽  
J. Maree
Keyword(s):  
Acid Mine Drainage ◽  
Flow Rate ◽  
Mine Drainage ◽  
Barium Carbonate ◽  
Pilot Scale ◽  
Carbonation Reaction ◽  
Column Reactor ◽  
Acid Mine ◽  
Sulphate Removal ◽  
Co2 Flow

Batch regeneration of barium carbonate (BaCO3) from barium sulphide (BaS) slurries by passing CO2 gas into a pilot-scale bubbling column reactor under ambient conditions was used to assess the technical feasibility of BaCO3 recovery in the Alkali Barium Calcium (ABC) desalination process and its use for sulphate removal from high sulphate Acid Mine Drainage (AMD). The effect of key process parameters, such as BaS slurry concentration and CO2 flow rate on the carbonation, as well as the extent of sulphate removal from AMD using the recovered BaCO3 were investigated. It was observed that the carbonation reaction rate for BaCO3 regeneration in a bubbling column reactor significantly increased with increase in carbon dioxide (CO2) flow rate whereas the BaS slurry content within the range 5–10% slurry content did not significantly affect the carbonation rate. The CO2 flow rate also had an impact on the BaCO3 morphology. The BaCO3 recovered from the pilot-scale bubbling column reactor demonstrated effective sulphate removal ability during AMD treatment compared with commercial BaCO3.

Recovery of calcium carbonate from waste gypsum and utilization for remediation of acid mine drainage from coal mines

2012 ◽  
Vol 66 (6) ◽  
pp. 1296-1300 ◽  
Author(s):  
J. Mulopo ◽  
V. Radebe
Keyword(s):  
Calcium Carbonate ◽  
Acid Mine Drainage ◽  
Sodium Carbonate ◽  
Mine Drainage ◽  
Coal Mines ◽  
Molar Ratio ◽  
Slurry Concentration ◽  
Acid Mine ◽  
Waste Gypsum ◽  
Pre Treatment

The recovery of calcium carbonate from waste gypsum (a waste product of the reverse osmosis (RO) desalination process) was tested using sodium carbonate. Batch recovery of calcium carbonate from waste gypsum slurries by reacting with sodium carbonate under ambient conditions was used to assess the technical feasibility of CaCO3 recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effect of key process parameters, such as the slurry concentration (%) and the molar ratio of sodium carbonate to gypsum were considered. It was observed that batch waste gypsum conversion significantly increased with decrease in the slurry concentration or increase in the molar ratio of sodium carbonate to gypsum. The CaCO3 recovered from the bench-scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with commercial laboratory grade CaCO3.

scholarly journals TEKNOLOGI PENGOLAHAN AIR ASAM TAMBANG BATUBARA “Alternatif Pemilihan Teknologi”

2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Nusa Idaman Said
Keyword(s):  
Acid Mine Drainage ◽  
Flow Rate ◽  
Active Treatment ◽  
Mine Drainage ◽  
Passive Treatment ◽  
Low Flow ◽  
Active Systems ◽  
Acid Mine ◽  
Reducing Conditions ◽  
Suitable Treatment

Acid Mine Drainage (AMD) treatment systems can be broadly categorised as either active or passive systems, which differ according to their ability to handle Acidity, flow rate and Acidity Load of the influent AMD.  Most passive and active systems utilise aggregate carbonate to neutralise the pH and encourage precipitation of metals as hydroxides or sulphide minerals.  In addition, passive treatment systems often use organic matter to provide alkalinity and create reducing conditions which favour the precipitation of metal sulphides.Active treatment systems can be engineered to accommodate essentially any acidity, flow rate and acidity load. Active treatment of AMD can be achieved using fixed plants or portable equipment for in-situ treatment. Passive treatment systems are almost invariably used for post closure treatment scenarios, and are best suited to AMD with low Acidity and low flow rates. The key factors in selection and design of active and passive AMD treatment systems are water chemistry including pH, metals, sulphate levels and redox state and flow rate of influent AMD, and the objectives of AMD treatment. Other important factors include capital and operating costs, availability of suitable treatment reagents or materials and sludge management issues. Keywords: Acid Mine Drainage, Active Treatment, Passive Treatment, Coal Mining.

scholarly journals Study of Inorganic Pollutants Removal from Acid Mine Drainage by Hemp Hurds

2016 ◽  
Vol 11 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Stefan Demcak ◽  
Magdalena Balintova
Keyword(s):  
Heavy Metals ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Mining Industry ◽  
Infrared Spectrometry ◽  
Acid Mine ◽  
Industrial Operations ◽  
Major Producer ◽  
Pollutants Removal ◽  
Pre Treatment

Abstract Sulphates in wastewaters have an origin as the by-products of a variety of industrial operations. A specific and major producer of such effluents, which contained sulphates and heavy metals, is the mining industry. These contaminants should be removed from wastewater using an adequate process of treatment. The paper deals with selected heavy metals (iron, cooper, and manganese) and sulphate removal from acid mine drainage outflowing from an abandoned mine in Smolnik (Slovakia) using the modified biosorbent - Holland hemp hurds. Pre-treatment of acid mine drainage was based on oxidation of ferrous cations from acid mine drainage by hydrogen peroxide and subsequent precipitation. The precipitate were analysed by infrared spectrometry which found the precipitate containing hydroxide and sulphate functional groups. During this process the concentration of sulphate decreased by 43.8 %. Hemp hurds modified by NaOH decreased concentration of Cu2+ in solution by about 70 %

scholarly journals Ferrite Formation Using Precipitates Neutralized by Calcium Carbonate in the Treatment of Acid Mine Drainage

2005 ◽  
Vol 121 (10/11) ◽  
pp. 521-531
Author(s):  
Haruka MARUYAMA ◽  
Toshifumi IGARASHI ◽  
Kuniomi ASAKURA ◽  
Hiroko MIYAMAE ◽  
Nobuyoshi IYATOMI ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Ferrite Formation ◽  
Acid Mine

scholarly journals Effects of Backfilling Excavated Underground Space on Reducing Acid Mine Drainage in an Abandoned Mine

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 777
Author(s):  
Kohei Yamaguchi ◽  
Shingo Tomiyama ◽  
Toshifumi Igarashi ◽  
Saburo Yamagata ◽  
Masanori Ebato ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Groundwater Flow ◽  
Flow Rate ◽  
Mine Drainage ◽  
Three Dimensional ◽  
Abandoned Mines ◽  
Abandoned Mine ◽  
Underground Space ◽  
Groundwater Levels ◽  
Acid Mine

Three-dimensional groundwater flow around an abandoned mine was simulated to evaluate the effects of backfilling the excavated underground space of the mine on reducing the acid mine drainage (AMD). The conceptual model of the groundwater flow consists of not only variable geological formations but also vertical shafts, horizontal drifts, and the other excavated underground space. The steady-state groundwater flow in both days with high and little rainfall was calculated to calibrate the model. The calculated groundwater levels and flow rate of the AMD agreed with the measured ones by calibrating the hydraulic conductivity of the host rock, which was sensitive to groundwater flow in the mine. This validated model was applied to predict the flow rate of the AMD when backfilling the excavated underground space. The results showed that the flow rate of the AMD decreased by 5% to 30%. This indicates that backfilling the excavated space is one of the effective methods to reduce AMD of abandoned mines.

Comparison of limestone, dolomite and fly ash as pre-treatment agents for acid mine drainage

2006 ◽  
Vol 19 (5) ◽  
pp. 454-462 ◽  
Author(s):  
S.S. Potgieter-Vermaak ◽  
J.H. Potgieter ◽  
P. Monama ◽  
R. Van Grieken
Keyword(s):  
Fly Ash ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Acid Mine ◽  
Pre Treatment

scholarly journals Improvement in pH and Total Iron Concentration of Acid Mine Drainage after Backfilling: A Case Study of an Underground Abandoned Mine in Japan

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1297
Author(s):  
Kohei Yamaguchi ◽  
Shingo Tomiyama ◽  
Toshifumi Igarashi ◽  
Saburo Yamagata ◽  
Masanori Ebato ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Flow Rate ◽  
Mine Drainage ◽  
Iron Concentration ◽  
Three Dimensional ◽  
Abandoned Mines ◽  
Analysis Model ◽  
Geochemical Model ◽  
Acid Mine

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 (SO42−) 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.

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