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.

scholarly journals The Physico-Chemical and Mineralogical Characterization of Mg-Rich Synthetic Gypsum Produced in a Rare Earth Refining Plant

2021 ◽  
Vol 13 (9) ◽  
pp. 4840
Author(s):  
Fatai Arolu Ayanda ◽  
Mohd Firdaus Mohd Anuar ◽  
Syaharudin Zaibon ◽  
Shamshuddin Jusop
Keyword(s):  
Rare Earth ◽  
Acid Soils ◽  
Acid Neutralization ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Neutralization Capacity ◽  
Acid Neutralization Capacity ◽  
Refining Plant ◽  
Calcium Magnesium

The physical, chemical and mineralogical characterization of the constituents of magnesium-rich synthetic gypsum produced in a rare earth-refining plant located in Gebeng, Pahang, Malaysia was conducted through elemental chemical analysis, scanning electron microscopy with Energy Dispersive X-ray (EDX)-analyzer, thermal analysis, X-ray fluorescence and X-ray diffraction. The crystalline nature of the by-product was studied using FTIR spectroscopy. Elemental analysis confirmed the presence of Ca and Mg, which are essential macronutrients required by plants and this Ca alongside the high pH (9.17) of MRSG may confer on the material a high acid neutralization capacity. From the result, it was observed that the studied by-product is a heterogeneous crystalline material comprising of gypsum (CaSO4.2H2O) and other major components such as calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate) and sulfur. These aggregates may contribute to give an acid neutralization capacity to MRSG. The XRD study of MRSG indicated a high content of gypsum (45.4%), shown by the d-spacing of 7.609 Å (2-theta 11.63) in the diffractogram. The infrared absorption spectra of MRSG indicate close similarities to mined gypsum. The results of the characterization indicated that MRSG has valuable properties that can promote its use in amending soil fertility constraints on nutrient-deficient tropical acid soils.

Preliminary Study of Neutralization and Inhibition of Chemolitotrophic Bacteria in an Acid Mine Drainage from Rio Tinto Site

2009 ◽  
Vol 71-73 ◽  
pp. 677-680 ◽  
Author(s):  
D. Carnicero ◽  
E. Díaz ◽  
O. Escolano ◽  
D. Rubinos ◽  
O. Ballesteros ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Red Mud ◽  
Mine Drainage ◽  
Initial Conditions ◽  
Microbial Populations ◽  
Low Grade ◽  
Neutralization Capacity ◽  
Acid Mine ◽  
Rio Tinto ◽  
Río Tinto

Limestone is commonly used for neutralization of acid mine drainage (AMD). Its main advantages are its lower price, sustained generation of alkalinity and production of low sludge volumes. Nevertheless, armouring of limestone by ferric hydroxides is a problem in oxic limestone drains and in active limestone treatment systems, reducing the efficiency of the process. Due to these disadvantages, there is a permanent search for cheaper and more effective neutralization agents. Many alkaline industrial wastes are gaining importance in the treatment of AMD. The possibilities to use two different industrial by-products, red mud from a bauxite exploitation and low grade magnesium hydroxide from a magnesite mine, as neutralizing and bacterial inhibiting agents, and the comparison with conventional limestone treatment has been studied in this paper. An AMD from Rio Tinto mine site with an initial pH of 2.4 and a ferric concentration of 1 g/L was used. Comparative test were done percolating the AMD in a continuous form with a peristaltic pump through three different columns filled with limestone, red mud and low grade magnesite, during one month and in same conditions of flow rate and amount of each compound used to fill the columns. The evolution of pH, iron and heavy metals, sulphates and microbial populations in the percolate were monitored at different times. The results showed that the best neutralization capacity was obtained with low grade magnesite during the month treatment. By contraire limestone and red mud loosed their neutralization capacity after 10 and 13 days respectively. The control of microbial populations showed that there is an inhibition of chemolithotropic bacteria as long as the materials maintain their neutralization capacity, reverting to the initial conditions when this capacity was loosed.

scholarly journals Arsenic (V) Removal by an Adsorbent Material Derived from Acid Mine Drainage Sludge

2020 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Erdenechimeg Byambaa ◽  
Jaeyoung Seon ◽  
Tae-Hyun Kim ◽  
Shin Dong Kim ◽  
Won Hyun Ji ◽  
...  
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Ferric Hydroxide ◽  
Health Concern ◽  
Maximum Adsorption Capacity ◽  
Arsenic Adsorption ◽  
Successful Operation ◽  
X Ray ◽  
Acid Mine ◽  
Bet Analysis

Arsenic is a toxic element that is often found in drinking water in developing countries in Asia, while arsenic poisoning is a serious worldwide human health concern. The objective of this work is to remove arsenic (V) (As(V)) from water by using an adsorbent material prepared from mine waste, called MIRESORBTM, which contains Fe, Al. The performance of the MIRESORBTM adsorbent was compared with granular ferric hydroxide (GFH), which is a commercial adsorbent. Adsorbents were characterized by using scanning electron microscopy (SEM), X-ray fluorescence spectroscopy (XRF), X-ray diffractometry (XRD), and N2 sorption with Brunauer–Emmett–Teller (BET) analysis. The kinetics, isotherms, and pH-dependency of arsenic adsorption were interrogated to gain insights into arsenic adsorption processes. The maximum adsorption capacity of MIRESORBTM was 50.38 mg/g, which was higher than that of GFH (29.07 mg/g). Moreover, a continuous column test that used environmental samples of acid mine drainage was conducted to evaluate the MIRESORBTM material for practical applications. The column could be operated for more than 5840 bed volumes without a breakthrough. Successful operation of a pilot plant using MIRESORBTM adsorbent was also reported. Thus, these studies demonstrate MIRESORBTM as a highly efficient and economical adsorbent derived from recycled mine sludge waste.

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.

Mineralogy and chemistry of ochre sediments from an acid mine drainage near a disused mine in Cornwall, UK

Clay Minerals ◽  
1999 ◽  
Vol 34 (2) ◽  
pp. 301-317 ◽  
Author(s):  
Balwant Singh ◽  
M. J. Wilson ◽  
W. J. McHardy ◽  
A. R. Fraser ◽  
G. Merrington
Keyword(s):  
Acid Mine Drainage ◽  
Photoelectron Spectroscopy ◽  
Mine Drainage ◽  
Close Association ◽  
Ammonium Oxalate ◽  
X Ray Diffraction ◽  
Thermal Methods ◽  
X Ray ◽  
Acid Mine ◽  
Transmission Electron

AbstractOchre sediments from acid mine drainage in Cornwall have been investigated using X-ray diffraction, thermal methods, infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy and chemical methods in order to determine their mineralogical and chemical composition. Fresh sediments consist of ferrihydrite and goethite. Large fractions of these minerals are dissolved by the ammonium oxalate treatment reflecting their poorly crystalline structure. Fresh sediments contain large amounts of surface-adsorbed SO4 (up to 9.3%) which is readily desorbed by the PO4 treatment. Goethite is the only mineral present in relatively older sediments and the mineral is well crystallized with rod-shaped morphology. Environmental conditions, such as pH and SO4 content, are not favourable for the presence of schwertmannite at the site. Iron minerals appear to be precipitating around filamentous algae and the shape of algae is preserved in the Fe oxide matrix. The ubiquitous presence of algae in close association with Fe minerals indicate their possible role in the crystallization of Fe oxides.

scholarly journals Analysis of the potential of acid mine drainage generation from the neutralized coal mining tailings

2021 ◽  
Vol 8 (4) ◽  
pp. 2925-2930
Author(s):  
Mihloti Nwamahoza Mdumela ◽  
Fhatuwani Sengani
Keyword(s):  
Acid Mine Drainage ◽  
Coal Mining ◽  
Mine Drainage ◽  
Environmental Crisis ◽  
Contributing Factors ◽  
X Ray ◽  
Mining Tailings ◽  
Acid Mine ◽  
Neutralizing Potential ◽  
Ultimate Objective

Mining activities specifically Coal Mining have been long testified to be one of the major contributing factors to environmental crisis, with Acid Mine Drainage (AMD) as one of the leading indicators. The purpose of this study was to assess the potential of AMD generation from neutralized coal mining tailings. In order to achieve the ultimate objective of the study, analysis of chemical composition and mineral content of the tailings using XRF (X-Ray Fluorescence) and XRD (X-Ray Diffraction) respectively, lastly, a static analysis such as ABA (Acid Base Accounting) and TCLP (Toxic Characteristic Leaching Procedure) were also conducted. The results have shown that the studied tailing samples had relatively higher Acid Potential (19 kg CaCO3/t to 20 kg CaCO3/t) versus the Neutralizing Potential (NP) (14 kg CaCO3/t to 18 kg CaCO3/t). It was also found that the Net Neutralizing Potential Ratio (NNPR) is less than zero (-1.5 kg CaCO3/t to -5.40 kg CaCO3/t which indicates that the tailings have the potential to generate acid. The low concentration of CaO indicates acidic potential of the samples because CaO is a buffering mineral. Based on the results of the study, it was concluded that Mine Tailings has the potential to generate acid; therefore, the contamination to the nearby watercourses is extremely possible if necessary remedial actions should be considered.

Neutralization of Acid Mine Drainage with Wood Ash

2018 ◽  
Vol 68 (12) ◽  
pp. 2768-2770
Author(s):  
Constantin Horia Barbu ◽  
Petronela Bianca Pavel ◽  
Cristina Maria Moise ◽  
Camelia Sand ◽  
Mihai Radu Pop
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Research Work ◽  
Wood Ash ◽  
Neutralization Capacity ◽  
Acid Mine ◽  
Research Activities ◽  
Mn Content ◽  
Mine Acid ◽  
Ash Disposal

The paper presents the research activities oriented to solving two environmental issues of concern: acid mine drainage that poses a great risk to soils and water, and wood ash disposal, which can be done only under strict conditions, with high costs. After trials with synthetic acid waters, the behavior of four types of ash has been investigated. The ashes used were originated from two boilers belonging to a fiberboard manufacturer, individually and mixed according to their production process, using acid mine drainage from a copper mine. Acid mine drainage has been characterized in what concern pH, fix and mineral residues, as well as Fe, Cu, Zn and Mn content. For all ashes and their mixtures, the pH (water suspension 1:5), humidity, as well as their neutralization capacity have been determined. The obtained results have been very good, proving that wood ash has better neutralization capacity than calcium carbonate, thus enabling to pursue and extend the present research work.

scholarly journals Initial pH and K+ concentrations jointly determine the types of biogenic ferric hydroxysulfate minerals and their effect on adsorption removal of Cr(VI) in simulated acid mine drainage

2018 ◽  
Vol 78 (10) ◽  
pp. 2183-2192 ◽  
Author(s):  
Yongwei Song ◽  
Jianyu Zhang ◽  
Heru Wang
Keyword(s):  
Acid Mine Drainage ◽  
Photoelectron Spectroscopy ◽  
Mine Drainage ◽  
Practical Significance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acid Mine ◽  
Adsorption Removal ◽  
Initial Ph ◽  
Strong Ability

Abstract It is of practical significance to promote the transformation of Fe in acid mine drainage (AMD) into ferric hydroxysulfate minerals with strong ability to remove heavy metals or metalloids. To investigate the types of biogenic ferric hydroxysulfate minerals generated in AMD by Acidithiobacillus ferrooxidans (A. ferrooxidans), different pH and K+ concentrations are tested for the formation of precipitates in media containing 160 mmol/L Fe2+. The Cr(VI) removal efficiencies of ferric hydroxysulfate minerals in AMD with different acidities are also compared. Results indicate that the mineralizing abilities of the initial pH levels (pH 3.0 > pH 2.5 > pH 2.0) and K+ concentrations (53.3 mmol/L > 3.2 mmol/L ≈ 0.8 mmol/L) differ, with cumulative Fe precipitation efficiencies of 58.7%, 58.0%, and 44.2% (K+ = 53.3 mmol/L), and 58.7%, 29.9%, and 29.6% (pH 3.0) after 96 h of A. ferrooxidans incubation, respectively. X-ray diffraction indicates that K-jarosites are formed in the treatments n(Fe)/n(K) = 0.1 and 3 at pH 2.0–3.0, while only schwertmannite is generated in a system of pH 3.0 and n(Fe)/n(K) = 200. X-ray photoelectron spectroscopy reveals that HCrO4− may be adsorbed as an inner-sphere complex on schwertmannite when the AMD pH is 3.0.

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