Mining Residues Research Articles

Anthropogenic influence on surface changes at the Olivares glaciers; Central Chile

We have investigated the source and role of light-absorbing impurities (LAIs) deposited on the glaciers of the Olivares catchment, in Central Chile. LAIs can considerably darken (lowered albedo) the glacier surface, enhancing their melt. We combined chemical and mineralogical laboratory analyses of surface and ice core samples with field-based spectral reflectance measurements to investigate the nature and properties of such LAIs. Using remote sensing-based albedo maps, we upscaled local information to glacier-wide coverage. We then used a model to evaluate the sensitivity of surface mass balance to a change in ice and snow albedo. The across-scale surface observations in combination with ice core analysis revealed a history of over half a century of LAIs deposition. We found traces of mining residuals in glacier surface samples. The glaciers with highest mass loss in the catchment present enhanced concentrations of surface dust particles with low reflectance properties. Our results indicate that dust particles with strong light-absorbing capacity have been mobilized from mine tailings and deposited on the nearby glacier surfaces. Large-scale assessment from satellite-based observations revealed darkening (ice albedo lowering) at most investigated glacier tongues from 1989 to 2018. Glacier melt is sensitive to ice albedo. We believe that an accelerated winter and spring snow albedo decrease, partially triggered by surface impurities, might be responsible for the above-average mass loss encountered in this catchment.

Trace element adsorption from acid mine drainage and mine residues on nanometric hydroxyapatite.

Mining Ag, Cu, Pb, and Zn sulfides by flotation produces great volume of residues, which oxidized through time and release acid solutions. Leachates from tailing heaps are a concern due to the risk of surface water pollution. Hydroxyapatite nanoparticles may remove trace elements from acid leachate collected from an oxidized tailing heap (pH ranged 1.69 ± 0.3 to 2.23 ± 0.16; [SO42-] = 58 ± 0.67 to 60.69 ± 0.39mmol). Based on the batch experiments under standard conditions, the average removal efficiency was 96%, 92%, 86%, and 67% for Cd, Pb, Zn, and Cu, respectively. The Zn adsorption was modeled by the Freundlich equation, but Cd, Cu, and Pb isotherms do not fit to Freundlich nor Lagmuir equations. Adsorption and other mechanisms occur during trace elements removal by hydroxyapatite. In the polymetallic system, trace elements saturate the specific surface of hydroxyapatite in the following order Zn, Cd, Cu, and Pb. The pH values must be higher than 7.5 to adsorb trace elements. The dose of 3.8% of hydroxyapatite to acid mine drainage removed efficiently > 80% of the soluble Fe, Cu, Mn, Zn, Cd, Ni, and Pb: 4020.0, 37.3, 34.8, 432.0, 4.4, 0.7, and 0.11mg L-1 from leachate A and 3357.1, 46.6, 27.8, 569.0, 4.7, 0.6, and 1.7 from leachate B, respectively. The application of 0.7% of hydroxyapatite decreased the extractable Pb in unoxidized tailing heaps from 272 to 100mgkg-1. It is likely to use hydroxyapatite to control trace element mobility from mine residues to surrounding soils and surface water.

Changes in fatty acid in Tecoma stans grown in mine residues after compost amendment

Amendment tailing heaps with compost may deplete metal(loid)s concentration and improve the conditions for plant development. This research aimed to compare the Tecoma stans ability to grow on soil from the Sonora desert and mining waste (MW) after amendment with compost. Amendment the MW, with compost, decreased soluble As, Cd, Cu, Mn, Pb, and Zn up to 47, 33, 11, 34, 69, and 34%, respectively; increased ten times the leaves weight, and thirteen times the leaf area of the plants. Arsenic, Cd, Pb, Cu, and Zn in plants tissues decreased 27, 28, 27, 12, and 11%, respectively. The bioaccumulation and translocation factors were lower than one, so T. stans do not accumulate these elements. Polyunsaturated fatty acids 18:2ω6 and 18:3ω3 were increased, suggesting lower alteration of thylakoidal membrane integrity due to compost treatment. But, the amendment to the tailing was not enough to deplete the abiotic stress.

Clinkering design of sulfobelite cements using clay overburden residue from bauxite mining

Sulfobelite (belite-rich calcium sulfoaluminate (BCSA)) cements are promising alternatives to ordinary Portland cement (OPC) due to their lower carbon dioxide generation and lower energy consumption in the clinkering process. Additionally, they are cost effective because of their less-restrictive raw meal composition compared with that of calcium sulfoaluminate (CSA), in which expensive bauxites are used as the alumina source. Diverse mining residues have been proved to be reliable alumina sources for BCSA production, including the clay residues that cover bauxites (Belterra Clay (BTC)) in the Brazilian Amazon region. The clinkering settings of BCSA using a different (less alumina) BTC were examined in this work. The mineralogy of the BCSA clinkers was optimised by a design of experiments and studied using X-ray powder diffraction, scanning electron microscopy and thermal analysis. The raw meal composition, boron doping and firing temperature were investigated to obtain the optimal clinker composition. Hydration of the cement pastes was investigated by calorimetry and the strength development of mortars was tested and compared with that of a commercial OPC. The BCSA mortars produced with gypsum additions developed compressive strength comparable to that that OPC within 28 days. The main hydrated phase was ettringite, with minor amounts of kuzelite, straetlingite and gibbsite.

Environmental assessment, microstructural behaviour, stress-strain characteristics, and effect of exposure to extreme temperature on sustainable concrete made with dolomite mining residues.

Mining and extraction of stones and minerals play a significant role in many countries economic growth in the world. The production of dolomite minerals in various industries in India and other countries produces vast amounts of waste in different fractions. Disposal of these types of industrial wastes in an immense quantity causes environmental pollution. The performance of dolomite mining residues on concrete properties as a fine aggregate substitute was examined. The microstructural analysis was conducted on the concrete samples to find the effect of dolomite mining residues in concrete. The stress-strain behaviour of the dolomite mining residues concrete was studied. The effect of exposure to elevated temperature and freeze-thaw on concrete properties containing dolomite mining residues was found up to 100% at 10% incremental order. The thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) tests were conducted on the dolomite mining residues and concrete samples. As a test result, concrete properties influence with the incorporation of the dolomite mining residues as a substitution of river sand, but no significant effect is observed in the concrete properties containing 10% dolomite mining residues. Up to 10% of dolomite production waste can be used as a sand substitute in concrete and other applications for sustainable development.

Technogenic Placer Deposits of the Artic Zone of Yakutia

The northern parts of the Arctic Zone of the Sakha Republic (Yakutia) are the most industrialized regions of the Republic. Since the 1930s, there has been intensive mining of alluvial and primary tin and gold placers. The 60-70-year mining operation has accumulated huge mining residues in the region, leaving behind useful components owing to deficiencies in mining technology at the time and deviations from mining technology. These wastes are considered technogenic placer deposits. The study of these wastes has identified the following types of technological s: 1 – technogenic placers of tin and gold; 2 - technogenic combined placers of gold and kularit; 3 - technogenic placers of tailings ponds consisting of mining wastes of gold and tin ore placers.

A study of hydromagnesite and nesquehonite precipitation in indirect aqueous carbonation of thermally-activated serpentine in a batch mode

To control and decrease the amount of greenhouse gases in the environment, the process of carbonation is attracting particular attention. Via carbonation, it is possible to control carbon dioxide (CO2) emissions by using mining residues. This study focuses on the precipitation step of aqueous indirect carbonation of serpentine mining wastes using the actual carbonated solution. To our knowledge, studies of magnesium carbonate precipitation have been based on synthetic solutions only, unlike the process in the present study. Three solutions prepared from the carbonation step with different concentrations were precipitated at temperatures ranging from 25 to 90 °C. The solution contained dissolved magnesium and inorganic carbon in addition to impurities, such as calcium and silica that are initially present in serpentine rock. Nesquehonite precipitated at reaction temperatures of 25, 40 and 50 °C. Hydromagnesite was precipitated at 60, 70, 80, and 90 °C via transition from nesquehonite. The study showed that increasing temperatures accelerate precipitation kinetics and hastens the transition period from nesquehonite to hydromagnesite. The investigation of the effects of the initial supersaturation showed that higher supersaturation promotes a better reaction yield and consequently a better sequestration potential, but lower supersaturation is better for crystal growth. However, supersaturation had no effect on the transition phenomenon from nesquehonite to hydromagnesite. Also, the grain sizes of the resulting minerals had different ranges from those obtained in synthetic solutions. The average size of the nesquehonite in our experiments was around 120 μm, while nesquehonite’s size was around 25 µm when prepared from a synthetic solution under relatively comparable operating conditions. The average size of the hydromagnesite was around 50 μm, while its size was around 30 µm when prepared from a synthetic solution, under relatively comparable the same operating conditions.

Synthesis and mechanical characterization of geopolymeric mortars derived from inorganic industrial waste from Peruvian informal mining

The geopolymeric mortars obtained by the chemical process of geopolymerization of waste from the Peruvian informal mining industry and subsequent addition of fine sand, were mechanically evaluated under ambient temperature and atmosphere conditions. The mechanical results found in the geopolymer mortars were compared with those found in conventional Portland cement mortars (control). The maximum uniaxial compressive stress values for the geopolymer mortars ranged from 7.5 to 27.1 MPa, with the best results when a binder:fine sand ratio of 1:2, molarity of the hardener solution of 20 M and a hardener solution:binder ratio of 0.6 was considered. The microstructure found for both types of mortars studied (control and geopolymeric) consisted of a continuous interconnected phase of binder (cement or geopolymerized inorganic mining residue) and a dispersed phase of small fine sand particles, located within the binder phase. The average real density and porosity of the geopolymeric materials studied were 2.71 g/cm3 and 27%, respectively.

Industrial waste management on example of Ukraine in the light of achieving sustainable development goals

This study object is industrial waste issue on the example of Ukraine: accumulation level, structure and its treatment possible ways. An analysis of waste sources available statistics on and their quantity was conducted. Іt is considered industrial wastes main component composition and corresponding types processing directions in Ukraine and abroad are analyzed. It is established the industrial waste accumulation level trends in Ukraine to increase year by year, and it's comparison with Gross Domestic Product shows an raw materials increase in the economy. Minor Downward Trends (2008–2009 and 2014–2016) illustrate decline in the industrial production during respective period. The largest industrial wastes producers are mining and processing industries. Six categories of industrial waste were identified, accounting for 4/5 of their total amount. These are sludge, «tails» and other iron ore wastes, iron ore mining wastes, limestone mining residues and waste from mining operations. Only iron ore tails enrichment technologies have been implemented at a sufficient level in Ukraine at present, but their processing level in terms of resource and energy savings is insufficient. The large relevant technologies have been introduced outside Ukraine and the most effective are includes maximum processing stages depth and included to technological production cycles. Based on this study results it is notes the best and most effective in the realities of Ukraine areas of waste management towards the implementation of 17 sustainable development goals are multi-component processing of six main categories of waste from the mining and processing industries. This approach avoids legal conflicts and has the highest environmental and economic effect.

Partitioning and mobility of arsenic (As) and lead (Pb) in an ancient Pb–Zn mine in central Mexico: Role of amorphous ferric arsenate

This study delves into the interactions between Pb and As and poorly-crystalline minerals, particularly amorphous ferric arsenate (AFA), in an ancient mine characterized by highly-dispersed pollutants due to strongly acidic conditions (pH 2.2 to 2.6) originated from mine drainage (AMD). On-site observations accompanied by laboratory-based mineral formation and transformation experiments were undertaken to examine the reactions of mobile Pb and As from abandoned mine residues on the mineralogy of the impacted sediments, as well as to examine associated controls on their mobility. Natural attenuation of Pb and As mobility predominantly occurred via formation of lead arsenate (PbHAsO4), Pb–As-rich Fe(III) minerals, and AFA, resulting in solid-phase concentrations ranging from ∼1088 to ∼1545 and from ∼278 to ∼734 mg kg−1 for Pb and As, respectively. Subsequent sorption experiments with synthetic AFA revealed the retention of Pb by the formation of anglesite (PbSO4) due to an appreciable sulfur content (up to 4 wt%) in AFA chemical composition, whereas As was effectively retained by a non-exchangeable surface adsorption mechanism. The results of this study show the occurrence of metastable phases like AFA in AMD environments as well as its role in controlling Pb and As mobility under strongly acidic conditions.

Chemical variations in mine water of abandoned pyrite mines exemplified by the Colorful Lakes in Wieściszowice, Sudetes Mountains, Poland

Study regionThis article contributes to understanding processes occurring in long-time abandoned, shallow and unremediated mining lakes exemplified by the Colorful Lakes near Wieściszowice, Southwest Poland. Study focusTemporal and spatial water chemistry variation and stable isotopic composition has been investigated in two sampling campaigns in wet and dry seasons. Novelties relating to these Lakes are that for the first time, depth and temporal dependent samples were studied chemically and isotopically. Water samples from various depths of the lakes and drainage water were analyzed for main ions, trace and semi-metals as well as sulfur and water isotopes. Data were interpreted statistically and with the chemical-thermodynamic code PHREEQC. New hydrological insights for the regionProcesses in the lakes are similar, resulting from rain and groundwater infiltrating the rocks and mine residues and leaching efflorescent salts. Differences result from the lakes’ depth, altitude, and source of inflow. They cause the Blue Lake to be in the Al- and the Yellow and Purple Lakes in the Fe-buffer-range. These lakes’ characteristics result either in stratification, evaporation influence or a well-mixed pit lake identified by the isotope variability. Isotope results further identified bacterial sulfate reduction throughout the lake water column during spring and summer. Saturation indices show an undersaturation in relation to most phases, and the species distribution in the lakes mirrors their individual buffer environment.

Project Review: SwampScapes

Project Review: <i>SwampScapes</i>

Passive treatment of acid mine drainage from the Sidi-Kamber mine wastes (Mediterranean coastline, Algeria) using neighbouring phosphate material from the Djebel Onk mine

Passive abiotic treatment of acid mine drainage (AMD) was investigated using phosphate mining residuals (raw low-grade phosphate ore, phosphatic limestone wastes, and phosphate mine tailings) from the Djebel Onk mine, Algeria. Laboratory batch tests were performed using the main expected lithologies of phosphate materials in contact with synthetic AMD, which had a low pH (3.08) and contained high concentrations of Fe (600 mg/L), Mn (40 mg/L), Mg (10 mg/L), Zn (20 mg/L), Cu (25 mg/L), As (50 mg/L), and sulfate (3700 mg/L). Phosphate materials were used as an oxic limestone drain to evaluate the increase in the pH of the AMD and metal removal by sorption and precipitation mechanisms. The results showed that all phosphatic lithologies were efficient in the passive treatment of AMD. The pH rapidly increased from 3.08 to 8.47 during water-rock interactions. The neutralization potential comparisons also showed that the phosphatic limestone wastes neutralized more acid than other lithologies. In addition, metals were efficiently removed (95.5% to 99.9%) by all materials. The results of batch sorption tests showed that the concentrations of metals in residual leachates did not exceed the Algerian criteria for industrial liquid effluents. Overall, these findings indicate that passive systems using phosphatic materials from the Djebel Onk mine can be effective for AMD treatment. The use of these mine wastes for passive treatment of AMD would allow the development of integrated management strategies for these residual materials in the context of sustainable development of phosphate mining.

Copernicus data to boost raw material source management: Illustrations from the RawMatCop programme

Earth Observation (EO) data can become an essential tool in the transformation of a raw materials sector that aims to reconfigure its model of operation. The high demand for the mineral resources necessary for the transition to a carbon neutral and circular economy conflicts with the increasing difficulties of finding new deposits. As the sector heads towards embracing circularity and reducing the environmental impacts, a clear focus has been set on developing appropriate tools to boost the efficiency of mineral resource management, both technologically and economically. In this scenario, the Sentinel satellites of the European Copernicus program come into play. Despite being satellites considered medium resolution, they provide great temporal and spatial coverage in a continuous record, which makes them tools with great potential for the raw materials sector. However, the lack of applications in the raw materials sector suggests that these technological advances have remained underrated by sectoral actors. The RawMatCop program was designed to bridge this gap. This program, co-funded by the European Commission and EIT RawMaterials, aims to develop applications and promote the use of Copernicus data in the raw materials sector to contribute to a safe and sustainable supply of mineral resources. The presented applications can be grouped into three categories covering the whole mining cycle from exploration to exploitation and post-mining. Two of the presented case studies cover the study of primary sources including exploration of Iron Oxide Copper Gold mineralisations to identify high-potential mining areas and mapping of informal gold mining and its environmental impacts. Another project focused on secondary sources tackled data applications for grade mapping and sample optimisation in mining residues. And the forth project focused on monitoring ground stability related to mining activity. The results demonstrate the high cost-effectiveness of Sentinel 1 and 2 in extending ground-based measurements to larger areas, especially when these are hard-to-reach areas. Finally, the presented projects examine the industrial and social impacts of technological innovations, as well as contribute to the achievement of prominent European Union policy objectives and the United Nations Sustainable Development Goals.

Desarrollo de morteros de bajo impacto ambiental a partir de residuos sílico-aluminosos activados alcalinamente del sector minero

Due to the environmental problems related to the generation of mine tailings, the circular economy is presented as a solution, using mine tailings as a raw material for the manufacture of construction materials. In this paper, mortars from alkaline-activated mining waste were generated. Coal mining residues (sandy-RC and clayey-RCd) and gold vein mining (flotation tails-CF) were studied, and they were activated by a mixture of NaOH and Na2SiO3 solution. Two types of mortars were analyzed to assess influence of particle size were manufactured, the first by using original granulometry tailing and the second with milled residue. In addition, for the milled residues, partial substitutions for Portland cement were used, and each type of mortar was set at 24 and 80°C. Crystalline phases in mortars were identified by X-ray diffraction (XRD), and the morphology of the fracture surfaces after the compression test was analyzed with scanning electron microscopy (SEM). The results show that the compressive strength of the specimens produced from milled residue was higher value in comparison with original granulometry specimens. In addition, setting temperature used does not represent the influence on the property evaluated. The best condition found presented a compressive strength of 17.7MPa for 24°C and 17.8MPa for 80°C, with reduction percentages of emissions and embodied energy of 32.85% and 22.73% respectively.

Influence of the fiber treatment and matrix modification on the durability of eucalyptus fiber reinforced composites

It is well known that the most important issue of cement-based composites is the durability of the natural fibers. The present study evaluates the effect of activated coal mining residues on the physical-mechanical properties of fiber cement composites reinforced by thermally treated eucalyptus pulp, before and after accelerated aging. The results showed that the partial substitution of cement by activated coal mining residues and the use of thermally treated fibers contribute to the improvement of the mechanical properties of the composites. Indeed, an increase of the values of the modulus of rupture (MOR) and the specific energy (SE) of the composites is observed under four-point bending flexural tests. Moreover, after accelerated aging tests, both fiber treatment and matrix modification contribute to mitigate the degradation of the fibers and increase the mechanical properties of the composites. According to the results of the study, the use of activated coal mining residues as partial substitution of cement and hornification treatment of the pulp, can lead to the improvement of the mechanical performance and durability of fiber cement composites.

Physical–Chemical Characterization of the Neves Corvo Extractive Mine Residues: A Perspective Towards Future Mining and Reprocessing of Sulfidic Tailings

Neves Corvo is an underground high-grade Cu–(Sn)–Zn mine, located in the Portuguese part of the world-class Iberian Pyrite Belt (IPB), which is currently producing copper, zinc, and lead concentrates. The operation is owned by SOMINCOR, a subsidiary of Lundin Mining, with a maximum capacity of 2.6 Mtpy for the copper processing plant and 1.0 Mtpy for the zinc processing plant. From 2010 till end of 2019, the mine has accumulated 7.3 Mt of waste rock and 17 Mt of thickened tailings. These mining residues are stored in Cerro do Lobo Tailings Management Facility (Cerro do Lobo TMF), which completes a volume of 47 Mt since the beginning of the operation in 1989 (30 Mt are slurry tailings). The deposition method changed in 2010 from slurry subaquatic deposition to sub-aerial thickened tailings stack (vertical expansion) in co-deposition with potentially acid-generating (PAG) waste rock. X-ray fluorescence analysis have shown copper and zinc grades variation in the waste rock between 0.12 and 0.4%, and 0.1% and 0.3%, respectively, and concentrations up to 0.6% and 1.3% of copper and zinc, respectively, in the tailings. Mineralogically, the tailings consist mainly in pyrite, sphalerite, chalcopyrite, ± arsenopyrite, ± tetrahedrite-tennantite, and gangue minerals such as quartz, phyllosilicates, carbonates, and some oxides, and have a non-uniform particle size distribution ranging between 1 and 100 µm. The waste rock fraction is millimetric to centimetric in size and is formed by the local host rocks, mineralogically consisting in quartz, chlorite (clinochlore and chamosite), calcite, and variably abundant disseminated sulfides, largely dominated by pyrite. Both mining residues might be envisaged as materials with valorization potential both for base metal recovery (tailings) and/or as non-metallic raw materials for construction or other applications (waste rock).Graphical Abstract

Impact of Tellurite on the Metabolism of Paenibacillus pabuli AL109b With Flagellin Production Explaining High Reduction Capacity.

Tellurium (Te) is a metalloid with scarce and scattered abundance but with an increased interest in human activity for its uses in emerging technologies. As is seen for other metals and metalloids, the result of mining activity and improper disposal of high-tech devices will lead to niches with increased abundance of Te. This metalloid will be more available to bacteria and represent an increasing selective pressure. This environmental problem may constitute an opportunity to search for microorganisms with genetic and molecular mechanisms of microbial resistance to Te toxic anions. Organisms from Te-contaminated niches could provide tools for Te remediation and fabrication of Te-containing structures with added value. The objective of this study was to determine the ability of a high metal-resistant Paenibacillus pabuli strain ALJ109b, isolated from high metal content mining residues, to reduce tellurite ion, and to evaluate the formation of metallic tellurium by cellular reduction, isolate the protein responsible, and determine the metabolic response to tellurite during growth. P. pabuli ALJ109b demonstrated to be resistant to Te (IV) at concentrations higher than reported for its genus. It can efficiently remove soluble Te (IV) from solution, over 20% in 8 h of growth, and reduce it to elemental Te, forming monodisperse nanostructures, verified by scattering electron microscopy. Cultivation of P. pabuli ALJ109b in the presence of Te (IV) affected the general protein expression pattern, and hence the metabolism, as demonstrated by high-throughput proteomic analysis. The Te (IV)-induced metabolic shift is characterized by an activation of ROS response. Flagellin from P. pabuli ALJ109b demonstrates high Te (0) forming activity in neutral to basic conditions in a range of temperatures from 20°C to 37°C. In conclusion, the first metabolic characterization of a strain of P. pabuli response to Te (IV) reveals a highly resistant strain with a unique Te (IV) proteomic response. This strain, and its flagellin, display, all the features of potential tools for Te nanoparticle production.

Effects of Different Fertilization Treatments on Soil Enzyme Activities in Coal Mining Residuals of Alpine Mining Area

Effects of Different Fertilization Treatments on Soil Enzyme Activities in Coal Mining Residuals of Alpine Mining Area

Life Cycle Assessment of Mortars Produced Partially Replacing Cement by Treated Mining Residues

The use of secondary mining resources to replace conventional constituents in mortars production has proved the effectiveness to preserve the quality of mechanical, physical, and chemical properties. However, minimal research has been performed to quantify the environmental impacts of mortars with mining residues. In the present work, a life cycle assessment of 10 mortars was carried out. A reference mortar (100% of cement binder) and mortars with cement substitutions in 10%, 25%, and 50% by raw, electrodialytic treated, and electrodialytic plus thermal treated mining residues were analysed. The impacts were studied in six environmental categories: (1) abiotic depletion; (2) global warming; (3) ozone depletion; (4) photochemical ozone creation; (5) acidification; and (6) eutrophication potentials. The results demonstrated that mortars formulated with raw mining residues may decrease the environmental impacts, namely in global warming potential (55.1 kg CO2 eq./t modified mortar). Considering the treatments applied to mining residues, the major mitigations were reported in photochemical ozone creation (−99%), ozone depletion (−76 to −98%), and acidification potential (−90 to −94%), mainly due to the disposal impacts avoided in comparison to the reference mortar. Analysing all mortars’ constituents and their management options, products with electrodialytic treated mining residues showed higher influence in ozone depletion (18 to 52%). Coupling a thermal procedure, mining residues contributed for 99% of the abiotic depletion potential of mortars.