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.

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.

Effects of Acid Mine Drainage of Coal Mines on Some Haematological Parameters of Channa punctatus (Bloch)

2017 ◽  
Vol 40 (2) ◽  
pp. 91-94
Author(s):  
B. Talukdar ◽  
H. K. Kalita ◽  
R. A. Baishya ◽  
S. Basumatary ◽  
A. Dutta ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Coal Mines ◽  
Channa Punctatus ◽  
Haematological Parameters ◽  
Acid Mine

An evaluation of waste gypsum-based precipitated calcium carbonate for acid mine drainage neutralization

2012 ◽  
Vol 65 (9) ◽  
pp. 1577-1582 ◽  
Author(s):  
J. N. Zvimba ◽  
J. Mulopo ◽  
L. T. Bologo ◽  
M. Mathye
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Acid Neutralization ◽  
Precipitated Calcium Carbonate ◽  
X Ray ◽  
Neutralization Capacity ◽  
Acid Neutralization Capacity ◽  
Acid Mine ◽  
Waste Gypsum ◽  
Major Oxide

Precipitated CaCO3 compounds recovered from pulped waste gypsum using some carbonate and hydroxide-based reagents were evaluated for their utilization in acid mine drainage (AMD) neutralization. The neutralization potentials, acid neutralization capacities and compositions of the CaCO3 compounds were determined and compared with some commercial CaCO3. It was observed that CaCO3 recovered from waste gypsum using Na2CO3 significantly neutralized AMD compared with commercial CaCO3 and that recovered using both (NH4)2CO3 or NH4OH-CO2 reagents. Moreover, a higher acid neutralization capacity of 1,370 kg H2SO4/t was determined for CaCO3 recovered from waste gypsum using Na2CO3 compared with an average of 721 and 1,081 kg H2SO4/t for ammonium-based CaCO3 and commercial CaCO3 respectively. The inorganic carbon content for the CaCO3 recovered using Na2CO3 and ammonium-based reagents of 49 and 34% respectively confirmed their observed neutralization potentials and acid neutralization capacities, while energy dispersive X-ray fluorescence suggested absence of major oxide impurities, with the exception of residual SO42− and Na2O which still requires further reduction in the respective compounds.

Geochemistry and stable isotope investigation of acid mine drainage associated with abandoned coal mines in central Montana, USA

2010 ◽  
Vol 269 (1-2) ◽  
pp. 100-112 ◽  
Author(s):  
Christopher H. Gammons ◽  
Terence E. Duaime ◽  
Stephen R. Parker ◽  
Simon R. Poulson ◽  
Patrick Kennelly
Keyword(s):  
Stable Isotope ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Coal Mines ◽  
Acid Mine ◽  
Abandoned Coal Mines ◽  
Central Montana

scholarly journals Effects of Long-Term Discharge of Acid Mine Drainage from Abandoned Coal Mines on Soil Microorganisms: Microbial Community Structure, Interaction Patterns and Metabolic Functions

2021 ◽  
Author(s):  
Di Chen ◽  
Qiyan Feng ◽  
Haoqian Liang
Keyword(s):  
Microbial Community ◽  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Coal Mines ◽  
Interaction Patterns ◽  
Nitrogen Fixing ◽  
Acid Mine ◽  
Metabolic Functions ◽  
Abandoned Coal Mines

Abstract More than twenty abandoned coal mines in the Yudong River basin of Guizhou Province have discharged acid mine drainage (AMD) for a long time. The revelation of microbial community composition, interaction patterns and metabolic functions can contributes to the ecological remediation of AMD pollution. In this study, reference and contaminated soils were collected along the AMD flow path for high-throughput sequencing. Results showed that the long-term AMD pollution promoted the evolution of γ-Proteobacteria, and the acidophilic iron-oxidizing bacteria Ferrovum (relative abundance of 15.50%) and iron-reducing bacteria Metallibacterium (9.87%) belonging to this class became the dominant genera. Co-occurrence analysis revealed that the proportion of positive correlations among bacteria increased from 51.02% (reference soil) to 75.16% (contaminated soil), suggesting that acidic pollution promotes the formation of mutualistic interaction networks of microorganisms. Metabolic function prediction (Tax4Fun) revealed that AMD contamination enhanced the microbial functions such as translation, repair, and biosynthesis of peptidoglycan and lipopolysaccharide etc., which may be an adaptive mechanism for microbial survival in extremely acidic environment. In addition, the acidic pollution promoted the high expression of nitrogen fixing genes in soil, and the discovery of autotrophic nitrogen fixing bacteria such as Ferrovum provided the possibility of bioremediation of AMD pollution.

scholarly journals Covellite (CuS) Production from a Real Acid Mine Drainage Treated with Biogenic H2S

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 206 ◽  
Author(s):  
Patricia Magalhães Pereira Silva ◽  
Adriano Reis Lucheta ◽  
José Augusto Pires Bitencourt ◽  
Andre Luiz Vilaça do Carmo ◽  
Ivan Patricio Ñancucheo Cuevas ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Raw Materials ◽  
Industrial Applications ◽  
Molar Ratio ◽  
High Concentration ◽  
Dissolved Metals ◽  
X Ray ◽  
Synthesis Conditions ◽  
Acid Mine

Acid Mine Drainage (AMD) is an environmental problem associated with mining activities, which resulted from the exposure of sulfur bearing materials to oxygen and water. AMD is a pollution source due to its extreme acidity, high concentration of sulfate, and soluble metals. Biological AMD treatment is one alternative to couple environmental amelioration for valuable dissolved metals recovery, as a new source of raw materials. Covellite (CuS) particles were synthetized from an AMD sample collected in a Brazilian copper mine, after 48 and 96 h of exposure to hydrogen sulfide (H2S) produced in a bioreactor containing acidophilic sulfate reducing bacteria (SRB). The time of exposure affected the morphology, nucleation, and size of CuS crystals. CuS crystals synthetized after 96 h of H2S exposure showed better ordination as indicated by sharp and intense diffractograms obtained by X-ray diffraction (XRD), and the predominance of placoid sheets with hexagonal habit structure as observed by scanning electrons microscopy (SEM). Energy dispersive X-ray fluorescence (EDXRF) spectrometry indicated a Cu:S molar ratio in agreement with CuS. Granulometric analysis demonstrated that 90% of CuS particles were less than 22 µm size. AMD biological treatment is a potential economical CuS recovery option for metallurgical process chain incorporation, or new industrial applications, since the alteration of synthesis conditions can produce different crystal forms with specific characteristics.

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