scholarly journals Geometallurgy of Trace Elements in the Hrazdan Iron Deposit

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1085
Author(s):  
Rob Bowell ◽  
Christopher Brough ◽  
Andrew Barnes ◽  
Arman Vardanyan
Keyword(s):  
Trace Elements ◽  
Iron Ore ◽  
Mine Drainage ◽  
Mine Waste ◽  
Mitigation Strategies ◽  
Iron Deposit ◽  
Acidic Ph ◽  
Metal Release ◽  
Waste Storage ◽  
Alkaline Mine Drainage

This study presents an evaluation of arsenic and other trace metals in the Hrazdan Iron-Ore project in Armenia using a methodology typically associated with Geometallurgical characterization. The principal host of the trace elements is pyrite and oxidized equivalents. Pyrite is a mineral of elemental concern as it has the potential to generate acidic pH in water that it contacts and thus mobilize metals of concern. In the Hrazdan deposit, there is a general excess of neutralizing carbonate minerals that result in adequate buffering of generated acid and limiting the mobility of metal cations in solution. However, metalloids that form oxyanions species such as those of arsenic or chromium tend to be more mobile in neutral to alkaline mine drainage. From the geometallurgical assessment of the mine waste, the results of the geochemical testwork can be explained and the information used to assess potential issues with mine waste storage, timing of metal release and provide a baseline for mitigation strategies.

scholarly journals Characterisation of Solid Mine Wastes Produced during Iron Ore Mining and Processing and their Potential Environmental Impacts

2021 ◽  
Author(s):  
Francis Xavier
Keyword(s):  
Environmental Impacts ◽  
Iron Ore ◽  
Mine Waste ◽  
Sampling Strategy ◽  
Mitigation Strategies ◽  
Petrographic Analysis ◽  
Mine Wastes ◽  
Waste Dump ◽  
High Concentration ◽  
X Ray

Abstract Solid waste deposited on the surface acts as a potential source of environmental pollution. High concentration of toxic elements in solid mine wastes can pose serious environmental risks. This study aims at characterising solid mine wastes produced due to iron ore mining and processing for their geochemistry and mineralogy. Samples were collected using a stratified sampling strategy. X-ray Fluorescence (XRF), X-ray Diffraction (XRD), and Petrographic analysis techniques were used. XRD analysis revealed a high abundance of Hematite (29%), with low amounts of Quartz stockpile samples. Berlinite (33%) amounts were high in waste dump samples, where Quartz was in high concentrations (34%) in the overburden samples. XRF analysis revealed a high amount of iron in the stockpile and waste dump, while Silica was highest in the overburden. Petrography analysis revealed major minerals in the solid mine waste: magnetite, Hematite, and Quartz with traces of mica, olivine, feldspar, and biotite. The minerals were characterised by a lamellar structure with mutual grain boundaries. Sulfide minerals that may cause acid drainage and various heavy metals were in considerable amounts. These elements have the potential of causing adverse environmental impacts hence the need for such characterisation to devise mitigation strategies and rehabilitation.

Colloid-borne uranium and other heavy metals in the water of a mine drainage gallery

2000 ◽  
Vol 88 (9-11) ◽  
Author(s):  
H. Zänker ◽  
W. Richter ◽  
V. Brendler ◽  
Heino Nitsche
Keyword(s):  
Heavy Metals ◽  
Trace Elements ◽  
Mine Drainage ◽  
Acidic Ph ◽  
Water Acidification ◽  
Toxic Trace Elements ◽  
Colloidal Form ◽  
Colloid Particles

The water of a mine drainage gallery was investigated for its contents of colloid-borne heavy metals with emphasis on uranium. About 1 mg/L of colloid particles of 100 to 300 nm were found. They consist of a matrix of Fe and Al oxyhydroxides and are formed when anoxic slightly acidic shaft waters mix with oxic near-neutral gallery water. The colloid particles bear toxic trace elements such as As, Pb, and Cu. Almost 100% of the As and Pb and about 70% of the Cu contained in the water are colloid-borne. Carbonato complexes prevent the uranyl from being adsorbed on the colloids in the unaltered gallery water. Acidification destroys these complexes: up to 50% of the uranium is attached to the colloids in the slightly acidic pH region. Further acidification converts the uranyl again to a ‘non-colloidal’ form.

scholarly journals Bioleaching of Pyrrhotite with Bacterial Adaptation and Biological Oxidation for Iron Recovery

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 295
Author(s):  
Bong-Ju Kim ◽  
Yong-Kwon Koh ◽  
Jang-Soon Kwon
Keyword(s):  
Mine Drainage ◽  
Mine Waste ◽  
Point Of Zero Charge ◽  
Biological Oxidation ◽  
Indigenous Bacteria ◽  
Bacterial Adaptation ◽  
Valuable Metals ◽  
Initial Ph ◽  
Dominant Member ◽  
Corrosion Pits

The microbially mediated recovery of valuable metals contained in mining waste presents an economical alternative to conventional hydrometallurgical processes. In order to investigate the effect of bacterial adaptation and biological oxidation on bioleaching, the microbially mediated bioleaching of a pyrrhotite sample from mine waste, with indigenous bacteria existing in acid mine drainage, was studied. The indigenous bacteria were sub-cultured repeatedly for iron adaptation, and Acidithiobacillus ferrooxidans was identified as the dominant member of the microbial consortium. The point of zero charge (PZC) of pyrrhotite sampled from mine waste was determined as 3.0. The performance of bioleaching by contact and non-contact biological oxidation was compared by conducting bioleaching under different initial pH (pHini) conditions (2.8 and 3.2). Negatively charged bacteria could be attached onto the pyrrhotite, which has a positive surface charge at lower pHini (2.8) than the PZC (3.0). Bacteria attachment and corrosion pits on the surface of the pyrrhotite residues were observed at pHini of 2.8. Under bacteria-adapted conditions, the leaching concentration of Fe (44.2 mg/L) at pHini of 2.8 was 2.1 times greater than that (21.3 mg/L) at pHini of 3.2. Under non-adapted bacteria conditions, the extent of Fe leaching was not significantly different between the pHini of 2.8 and 3.2. This could be attributed to the fact that the adapted bacteria could more easily attach onto the pyrrhotite surfaces at pHini 2.8, allowing contact biological oxidation during the bioleaching experiments. We demonstrate here that the bioleaching of pyrrhotite could increase Fe recovery through bacterial adaptation and contact biological oxidation.

scholarly journals A Test of Two Methods for Waste Rock Drainage Quality Prediction: Aqua Regia Extraction and Single-addition Net-acid Generation Test Leachate Analysis

2021 ◽  
Author(s):  
Teemu Karlsson ◽  
Lena Alakangas ◽  
Päivi Kauppila ◽  
Marja Liisa Räisänen
Keyword(s):  
Mine Drainage ◽  
Mine Waste ◽  
Extraction Methods ◽  
Drainage Water ◽  
Waste Rock ◽  
Quality Prediction ◽  
Aqua Regia ◽  
Acid Generation ◽  
Leachate Analysis ◽  
Single Addition

AbstractThe mobility of contaminants from mine waste can be assessed using different extraction methods. Aqua regia (AR) extraction is the most commonly used method in Finland. Another method is the analysis of leachate from net acid generation (NAG) tests, which is primarily designed for acid production potential assessment. We investigated the performance of single-addition NAG test leachate analysis and AR extraction in drainage quality prediction, using waste rock and drainage water samples from several Finnish waste rock sites. Our objective was to improve interpretation of the AR and single-addition NAG test leachate analysis results in drainage quality prediction. The AR extraction effectively reflected elements that occurred in elevated concentrations in drainage water, though it over-predicted Al, As, Cd, Co, Cu, and Ni in some circumneutral drainages, and Cr in general. The single-addition NAG test leachate analysis also performed well in assessing the mobility of contaminants including Al and Cr at acid mine drainage sites. As the contaminants tend to precipitate in neutral NAG test solution, the usability of the method in neutral mine drainage cases should be further investigated. Furthermore, the conclusions presented in this study are limited to waste rock samples collected from the surface of piles; future work will examine waste rock history, dump cores, drainage quality changes, etc. in more detail.

scholarly journals Effect of Cadmium, Copper and Lead on the Growth of Rice in the Coal Mining Region of Quang Ninh, Cam-Pha (Vietnam)

2018 ◽  
Vol 10 (6) ◽  
pp. 1758 ◽  
Author(s):  
J. Marquez ◽  
Olivier Pourret ◽  
Michel-Pierre Faucon ◽  
Sebastian Weber ◽  
Thi Hoàng ◽  
...  
Keyword(s):  
Trace Elements ◽  
Trace Metal ◽  
Contaminated Soils ◽  
Mine Waste ◽  
Local Population ◽  
Rice Paddy ◽  
Coal Extraction ◽  
Open Pit ◽  
Metal Concentrations ◽  
Rice Paddy Soils

The goal of this study was to quantify the mobility and partitioning of trace elements originating from mine waste rocks derived from open pit coal extraction activities. The results showed that native rice plants were adapted to growing in metal contaminated soils, posing a severe health risk to local population. Sequential extraction procedures and bulk soil chemical analyses both suggest enrichment of Cd, Pb and Cu in rice paddy soils. Lead was shown to be evenly partitioned among all mineral and organic phases. Copper was associated with carbonates and organic matter. Smaller fractions of Pb and Cu were also bound to Fe and Mn oxides. Only 25% of Cd, 9% of Pb and 48% of Cu were associated with the exchangeable fraction, considered mobile and thus bioavailable for plant uptake. Effects of Cd, Cu and Pb on local Cam Pha Nep cai Hoa vang, and control Asia Italian rice, showed marked differences in growth. The local Vietnamese variety grew close to control values, even upon exposure to higher trace metal concentrations. Whereas the development of the control rice species was significantly affected by increasing trace metal concentrations. This result suggests toxic trace elements accumulation in the edible parts of crops.

Spreading of pollutants from alkaline mine drainage. Rodalquilar mining district (SE Spain)

2012 ◽  
Vol 106 ◽  
pp. 69-74 ◽  
Author(s):  
V. González ◽  
I. García ◽  
F. del Moral ◽  
S. de Haro ◽  
J.A. Sánchez ◽  
...  
Keyword(s):  
Mine Drainage ◽  
Mining District ◽  
Se Spain ◽  
Alkaline Mine Drainage

scholarly journals Characterisation of Tailings from Itakpe Iron Ore Mine, Itakpe, Nigeria

2021 ◽  
Vol 4 ◽  
pp. 1-8
Author(s):  
R.A. Adebimpe ◽  
A.O. Fatoye
Keyword(s):  
Specific Gravity ◽  
Food Chain ◽  
Iron Ore ◽  
Mine Waste ◽  
Cadmium Concentration ◽  
Metal Mobility ◽  
Residual Fraction ◽  
Base Line ◽  
Iron Ore Mine ◽  
Waste Dumps

Knowledge of tailings characteristics is required for utilisation and management purposes in the mining and construction industry. Tailings from the mine waste dumps at Itakpe iron ore mine were collected and analysed in the laboratory to determine their chemical and physical characteristics and these include; permeability, porosity, specific gravity, particle size distribution, chemical composition and bioavailability factor of element. Geochemical speciation with quantitative X-ray powder diffraction was used to evaluate the chemical and mineral composition of Itakpe iron ore tailings. The aim is to offer base line data necessary to assess metal mobility and bioavailability. The distribution of heavy metals such as Cu, Ni, Cd, Cr, Zn and Fe was determined using multi- step sequential extraction. The results obtained indicate that the permeability is 6.24 x 10-3 cm/sec; porosity is 35%; and specific gravity is 3.58. The tailings is well graded and is sand gravel. Nickel and Zinc was found to be considerably high in exchangeable and bound to carbonates fraction which are mobile region and is bound to Fe – Mn oxides which is slightly mobile region but the higher concentration of Ni found in residual fraction. The implication of this result is that Nickel and Zinc partially enter into the food chain. Chromium and Cadmium concentration result indicated that these metals can easily enter into the food chain because of their presence in the mobile region and their higher mobility percentage.

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