Gold Mine Tailings Research Articles

Effect of cow manure mon the growth of water spinach in gold mine tailing

Gold mining activities produce abundant tailings waste. The negative impacts of tailing pollution on agriculture include soil profile loss, soil compaction, depletion of essential nutrients, organic matter, and soil pH, making it difficult for plants to grow. Cow manure (CM) is a well-known soil amendment to improve soil quality and facilitate root growth. Animal manure fertilizers contain a complete range of macro and micronutrients required by plants. In addition to its ability to enhance soil fertility, CM can also promote plant growth in former mining areas or mineral tailings. The objective of this study was to determine the effect of CM application rates on water spinach plant growth improvement. The experimental design used was a Completely Randomized Block Design (CRBD) with four treatments and six replications. The experimental treatments consisted of a control (without treatment), 10 t ha-1, 20 t ha-1, and 30 t ha-1 of CM. The results of the experiment showed that CM application increased plant height, leaf count, stem diameter, and wet weight of water spinach plants. The application of 10 t ha-1 CM showed the highest growth improvement in terms of plant height, leaf count, stem diameter, and wet weight of plants grown in gold mining tailings compared to other treatments. This experiment highlights the importance of CM for water spinach cultivation in tailing areas.

Total Bacteria and Fungi in Gold-Mine Tailing in Buru of Indonesia after Three-Year Natural Revegetation

The concern of agricultural environment damage due to amalgamation process of gold mining in Indonesia is increased. Gold mine tailing deposition in agricultural land pose a serious problem about the mercury (Hg) accumulation in soil. The objective of this study was to verify the population of heterotroph-aerobic bacteria and filamentous fungi in the tailing deposit grown with pioneer plants in comparison to both population in bare tailing after three-year revegetation. Moreover, the research was conducted to analyze the different of acidity (pH) and electrical conductivity (EC) of both sites. The study area was performed in artisanal and small-scale gold mining in Waelo village of Buru Regency, Maluku Province. The bacterial and fungal population in tailing that is naturally grown by sedges and grasses were lower than that in bare tailing without vegetation. In general, the bacterial and fungal count of tailing with vegetation was 9.3 and 4.3. while in bare tailing were 8.49 and 3.79. The acidity of both locations was not different but the pH was strongly acid ranged from 3.52-4.29. The EC was lower (21.61) in the tailing with vegetation compared to bare tailing without vegetation (58.94). This study suggested that the fungal and bacterial population as well as pH were increased after revegetation that benefit plant growth.

Effect of microbial-induced calcite precipitation on shear strength of gold mine tailings

Effect of microbial-induced calcite precipitation on shear strength of gold mine tailings

Heavy metals content in sweet potato (Ipomoea batatas L.) grown on soil contaminated by gold mine tailings with composted cow manure amendment

Artisanal gold miners usually dispose of gold mine tailings in storage ponds or agricultural land used for farming. However, the gold mine tailings still contain heavy metals such as cadmium, copper, lead, and zinc and can lead to bioaccumulation in food chains. This study investigated the influence of composted cow manure as organic fertilizer on heavy metals (Cd, Cu, Pb and Zn) content in sweet potatoes grown on soil contaminated by gold mine tailing. The MZ119 clone sweet potato plants were grown on soils added with mixtures of gold mine tailings at ratios of 0% (control), 30%, 50%, 70%, and 100% (w/w), and composted cow manure (0, 250, 500, and 750 g/10 kg of soil). The results showed that the higher the ratio of gold mine tailings to the soil, the higher the accumulation of metals in sweet potatoes. According to the translocation factor (TF) value, heavy metals (Cd, Cu, Pb and Zn) accumulated higher in the shoots than in the roots of sweet potatoes. Accumulation of heavy metals in sweet potato occurred in the following order: Zn>Cu>Pb>Cd. This study recommends that sweet potatoes could be used for the phytoremediation of heavy metals (Cd, Cu, Pb and Zn) in polluted soils, but the plants may not be used for consumption.

Selected rhizobacteria facilitated phytoremediation of barren and heavy metal contaminated gold mine tailings by Festuca arundinacea

Gold mine tailings pose a significant challenge for phytoremediation due to their poor nutrition and heavy metal pollution. Rhizobacteria-assisted phytoremediation is a promising method, yet limited research has been conducted on its application in gold mine tailings. In this study, rhizobacteria R1 (Bacillus paramycoides) and R2 (Klebsiella michiganensisW14T) were isolated from the rhizosphere of Festuca arundinacea (F. arundinacea) to enhance the phytoremediation of gold mine tailings. Our results showed that inoculation of R1 and R2 led to a significant increase in the average germination rates of F. arundinacea by 36.9% and 16.5%, respectively. Furthermore, the average plant height increased by 68.3% and 53.4%, respectively. Importantly, after inoculation with rhizobacteria, the contents of Mn, Pb, and As in F. arundinacea increased by 13.2–33.9%, 40.1–41.0%, and 98.1%–124.5%, respectively, indicating that the rhizobacteria enhanced the plant uptake of heavy metals. The improved nutrient content and enzyme activity in the tailings after inoculation with rhizobacteria were positively correlated with the heavy metal content in F. arundinacea. In addition, inoculation of rhizobacteria significantly altered the microbial community structure of the tailings, with Bacillus becoming the dominant genus in the rhizosphere tailings of F. arundinacea after R1 inoculation. Overall, our findings demonstrated that rhizobacteria R1 was better to enhance the phytoremediation of gold mine tailings. These results offer valuable insights into the mechanism of rhizobacteria-assisted phytoremediation and provide a practical method to enhance remediation of gold mine tailings.

Production and Incorporation of Calcium-Hydrolyzed Nanoparticles in Alkali-Activated Mine Tailings.

This work presented the production and incorporation of calcium-hydrolyzed nano-solutions at three concentrations (1, 2, and 3 wt.%) in alkali-activated gold mine tailings (MTs) from Arequipa, Perú. As the primary activator solution, a sodium hydroxide (NaOH) solution at 10 M was used. Calcium-hydrolyzed nanoparticles with a particle size of 10 nm were localized inside self-assembled molecular spherical systems (micelles) with diameters of less than 80 nm that were well-dispersed in aqueous solutions and acted as secondary activator, and also as additional calcium resource for alkali-activated materials (AAMs) based on low-calcium gold MTs. High-resolution transmission electron microscopy/energy-dispersive X-ray spectroscopy (HR-TEM/EDS) analyses were carried out to characterize the morphology, size, and structure of the calcium-hydrolyzed nanoparticles. Fourier transform infrared (FTIR) analyses were then used to understand the chemical bonding interactions in the calcium-hydrolyzed nanoparticles and in the AAMs. Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) and quantitative X-ray diffraction (QXRD) were performed to study the structural, chemical, and phase compositions of the AAMs; uniaxial compressive tests evaluated the compressive strength of the reaction AAMs; and nitrogen adsorption-desorption analyses measured porosity changes in the AAMs at the nanostructure level. The results indicated that the main cementing product generated was amorphous binder gel with low quantities of nanostructured C-S-H and C-A-S-H phases. The surplus production of this amorphous binder gel produced denser AAMs at the micro-level and nano-level (macroporous systems). In addition, each increase in the concentration of calcium-hydrolyzed nano-solution had a direct/proportional effect on the mechanical properties of the AAM samples. AAM with 3 wt.% calcium-hydrolyzed nano-solution had the highest compressive strength, with a value of 15.16 MPa, which represented an increase of 62% compared with the original system without nanoparticles that were aged under the same conditions at 70 °C for seven days. These results provided useful information about the positive effect of calcium-hydrolyzed nanoparticles on gold MTs and their conversion into sustainable building materials through alkali activation.

Effect of Cow Manure on Soil Organic Carbon, Total Nitrogent, and Growth of Choy Sum in Gold Mine Tailings

Mining activities in Bogor, Indonesia produce tailings contaminated with heavy metal Hg that can cause damage to physical, chemical, and soil properties. This research was carried out from October 2022 to February 2023 at greenhouse experiment was conducted in Jatinangor Campus, Faculty of Agriculture, Universitas Padjadjaran, West Java, Indonesia. The use of cow manure (CM) can improve substrate characteristics from tailings. The research was conducted to determine the effect of cow manure on plant height, number of leaves, fresh and dry shoot weight, organic-carbon, and total soil nitrogent. Greenhouse research was set up in Factorial Randomized Block Design. Choy sum plant variety is Shinta were planted 35 days with five treatments and five replications of CM. The used 450 g CM mixed with 550 g tailing gave the highest plant height, number of leaves, fresh and dry shoot weight of plant; organic-carbon, and total nitrogent in substrate. The experiment suggested that tailing mixed with CM is prominent to improve substrate characteristics and growth of choy sum.

Use of limekiln dust in the stabilization of heavy metals in Ghanaian gold oxide ore mine tailings.

Remedial action for heavy metal-contaminated soils is imperative for preventing heavy metal leachability and minimizing environmental risks. This study evaluated the use of limekiln dust (LKD) as a heavy metal stabilization agent for Ghanaian gold mine oxide ore tailing material. Heavy metal-laden tailing material (Fe, Ni, Cu, Cd, and Hg) was collected from a tailing dam site in Ghana. Stabilization was done using acid neutralization capacity (ANC) and citric acid test (CAT) while all chemical characterization was done using X-ray fluorescence (XRF) spectroscopy. Various physicochemical parameters including pH, EC, and temperature were also measured. The contaminated soils were amended with LKD in doses of 5, 10, 15, and 20 wt.%. The results revealed that the contaminated soils had concentrations of heavy metals above FAO/WHO stipulated limits of 350, 35, 36, 0.8, and 0.3mg/kg for Fe, Ni, Cu, Cd, and Hg, respectively. After 28days of curing, 20 wt.% of LKD was found to be appropriate for the remediation of the mine tailings of all the heavy metals studied except Cd. Ten percent of the LKD was noticed to be enough in remedying soil contaminated with Cd since the Cd's concentration reduced from 9.1 to 0.0mg/kg with a stabilizing efficiency of 100% and a leaching factor of 0.0. Therefore, remediation of contaminated soils of Fe, Cu, Ni, Cd, and Hg with LKD is safe and environmentally friendly.

Valorization potential of N-rich zeolite and moving bed biofilm reactor (MBBR) biomass in the revegetation of non-acid generating gold mine tailings

Treatment of ammonia nitrogen (NH3−N) in mine effluents generates N-rich residual materials, such as moving bed biofilm reactor (MBBR) biomass and spent zeolite. Using them as substitutes for mineral fertilizers in revegetation of mine tailings avoids disposal and contributes to a circular economy. The study evaluated the effect of MBBR biomass and N-rich zeolite amendments on above- and below-ground growth and foliar nutrient and trace element concentrations of a legume and several graminoid species grown on non-acid generating gold mine tailings. N-rich zeolite (clinoptilolite) was produced by treating saline (up to 60 mS/cm) synthetic and real mine effluents (250 vs 280 mg/L NH3-N). A three-month pot experiment was conducted with a dose of tested amendments equivalent to 100 kg/ha N and compared to unamended tailings (as negative control), tailings with a mineral NPK fertilizer, and a topsoil (as positive controls). Higher foliar N concentrations were found in amended and fertilized tailings vs negative control, but N was less available in the zeolite treatments than in other tailings treatments. For all plant species, the mean leaf area and above-ground, root, and total biomasses were similar in the zeolite-amended tailings to the unamended tailings, while the MBBR biomass amendment resulted in similar above- and below-ground growth to the NPK fertilized tailings and the commercial topsoil. Trace metal concentrations in water leaching from the amended tailings remained low, but tailings amended with zeolite exported NO3-N concentrations up to 10 times greater (>200 mg/L) after 28 days compared to all other treatments. Foliar Na concentrations in zeolite mixtures were six to nine times higher than in other treatments. The MBBR biomass is a promising potential amendment for revegetation of mine tailings. However, Se concentrations in plants after MBBR biomass amendment should not be underestimated, while Cr transfer from tailings to plants was observed.

Pollution assessment of mercury and other potentially toxic elements in the marine sediments of Mambulao Bay, Jose Panganiban, Camarines Norte, Philippines

In Jose Panganiban, Camarines Norte, small-scale gold miners dispose of untreated tailings into nearby rivers, which eventually flow into Mambulao Bay. In this study, nine (9) marine sediments were collected and analyzed to assess the pollution of potentially toxic elements (PTEs) in Mambulao Bay. Au concentrations in the sediments were also determined. The results showed that the Mambulao Bay sediments have high concentrations of Hg and other PTEs. The average concentrations of potentially toxic elements in the marine sediments were observed in the following order: Zn (638 mg/kg) > Pb (297 mg/kg) > Cr (283 mg/kg) > Cu (209 mg/kg) > Ni (146 mg/kg) > As (35 mg/kg) > Hg (4.4 mg/kg) > Cd (1.4 mg/kg). Geoaccumulation index values suggest that Mambulao Bay sediments close to the Danao River estuary are strongly to extremely polluted by Hg, strongly polluted by Pb, moderately to strongly polluted by Zn, and moderately polluted by Cd, Cu, Cr, Ni, and As. A high average Au concentration (0.42 mg/kg) was also reported in the sediments. The enrichment values suggest that the PTE pollution has an anthropogenic origin, most likely from the artisanal gold mine tailings of Jose Panganiban. Most of the marine sediments have Hg, Pb, Zn, and Cu concentrations above the probable effect levels for PTEs, which can result in occasional adverse biological effects on the aquatic biota of Mambulao Bay. The average Hg content of Mambulao Bay sediments is higher than those of Honda and Agusan Bays, while the average Pb and Zn contents are higher than those of Honda and Butuan Bays, Boac River estuary, and Tañon Strait. These results can help the government address marine pollution in Mambulao Bay for sustainable aquatic resources and coastal management and can serve as a baseline for future monitoring and assessment of the water body.

Analysis of the Current Legal Framework Protecting the Health of Communities Near Gold Mine Tailings in South Africa

South Africa has a robust legal framework to ensure that mine tailings do not become a health hazard. This notwithstanding, this article will show how a lack of effectiveness with regard to implementation and compliance has led to a situation where the health and safety of people living in communities near gold mine tailings are constantly threatened. This health hazard is exacerbated by human settlements being developed too close to mine tailings, a consequence of poor monitoring, planning and control. The authors explain how the problem could be remedied through effective implementation and compliance with the legal framework and concerted efforts between the government, mining companies and affected communities. Similarly, the establishment of exclusion zones is key to limiting exposure to pollution. At the same time, awareness campaigns will ensure that community members are equipped with the knowledge to safeguard themselves against health hazards caused by gold mine tailings.

Cyanide Biodegradation by a Native Bacterial Consortium and Its Potential for Goldmine Tailing Biotreatment

A native cyanide-degrading bacterial consortium was isolated from goldmine tailing sediments. Mine tailings are toxic effluents due to their metal–cyanide complexes. The bacterial consortium was able to degrade an initial sodium cyanide concentration ranging from 5 to 120 mg L−1 in alkaline synthetic wastewater (pH > 9.2), for a maximum of 15 days. The free cyanide biodegradation efficiency was 98% for the highest initial free cyanide concentration tested and followed a first-order kinetic profile, with an estimated kinetic rate constant of 0.12 ± 0.011 d−1. The cyanide-degrading consortium was streaked with serial dilutions on a specific medium (R2A). 16S rRNA gene sequencing and mass spectrometry proteomic fingerprinting of the isolates showed that the bacterial strains belonged to Microbacterium paraoxydans, Brevibacterium casei, Brevundimonas vesicularis, Bacillus cereus and Cellulosimicrobium sp. The first four genera had previously been identified as cyanide-degrading bacteria. Microbacterium and Brevibacterium had previously been found in alkaline conditions, showing resistance to heavy metals. As for Cellulosimicrobium, to our knowledge, this is the first study to implicate it directly or indirectly in cyanide biodegradation. In this research, these genera were identified as functional bacteria for cyanide degradation, and they might be suitable for mine tailing biotechnological tertiary treatment.

Biochar, compost and/or NPK fertilizer affect the uptake of potentially toxic elements and promote the yield of lettuce grown in an abandoned gold mine tailing

Background and study objectives: The low soil quality status and the high concentrations of potentially toxic elements (PTEs) found in gold mine tailings make them unfit for crop production. Assessing the possibility of mine tailings for crop production after mining is important since the presence of these PTEs harms food safety and human health. In this study, we aimed to investigate the effects of biochar, poultry litter compost, and inorganic fertilizer on the uptake of PTEs and the soil quality improvement of tailings from a decommissioned mine tailing in Ghana.Materials and methods: Rice husk biochar, poultry litter compost, and NPK were applied alone or in combination to the abandoned mine tailings at the rate of 5 t ha−1. After a 42-day pot experiment, we extracted the content of nutrients and PTEs in the soil and plant, and determined their uptake by the Lactuca sativa L.Results and discussion: Rice husk biochar, poultry litter compost and NPK applied alone or in combination significantly increased the soil pH, organic matter, available P as well as the CEC (Ca2+, K+, Mg2+, Na+) but reduced the exchangeable acidity in the mine tailings. Additionally, tailings amended with NPK increased the N uptake by 42%. Also, tailings amended with 2.5 t ha−1 biochar + 2.5 t ha−1 NPK increased both P and K uptake by 128% and 101%, respectively. For PTE uptake (i.e., Pb, Hg, As, Cd, and Cr), biochar, poultry litter compost and their combinations reduced the Hg uptake (mg kg−1) in the pot by a maximum 49% as compared to the control. Plausible formation of metal-hydroxo complexes at high pH with its consequent strong adsorption of Hg and presence of exchangeable K which contributed to the ion binding strength of the amended mine tailings reduced mobility and uptake of Hg by the lettuce. However, biochar, compost, and/or inorganic fertilizer enhanced Cd, Cr, and Pb uptake, which may pose lettuce food chain contamination problems for the inhabitants.Conclusion: As a result, we conclude that the use of inorganic NPK fertilizer and rice husk biochar can be used to improve the soil quality of abandoned gold mine tailings for safe food production, minimize Hg uptake by lettuce, and lower the associated environmental risk.

Brainstorming Business Model Canvas Pada Formulasi Strategi Optimalisasi Sedimentasi Tailing Tambang Emas Pada Pertambangan Emas Skala Kecil di Koperasi Produsen Tombang Tujuah Loge

Alluvial gold mining tailings in Logas consist of sand and mud, which are dominated by silica minerals and feldspar; the fine sand size fraction and the picking fraction are dominated by silica minerals, metals, and other high-hardness minerals. Tailings pose a new problem, namely sedimentation, which results in the silting of rivers, which causes flooding and damages community plantations. Tailings still have economic value, which can provide a source of income for the Tombang Tujuah Loge Producers Cooperative. This study formulates the idea of "stakeholders" so that all parties can participate in planning their business strategies. The Brainstorming Business Model Canvas method is able to explore potential ideas from stakeholders who are usually reluctant to convey ideas orally. The results of this study obtained the Business Model Canvas for strategy formulation regarding the development of a tailings utilization business.an bisnis pemanfaatan tailing

Heavy Metal Speciation by Tessier Sequential Extraction Applied to Artisanal Gold Mine Tailings in Eastern Cameroon

Heavy Metal Speciation by Tessier Sequential Extraction Applied to Artisanal Gold Mine Tailings in Eastern Cameroon

Physicochemical Properties, Heavy Metal Composition, and Metal Resistant Microorganisms Associated with Gold Mine Tailings in Jebba, Nigeria

Mine tailings are a source of unique microorganisms with novel characteristics. This study aims to determine the chemical composition of the soil and water from different locations of an active artisanal gold mine and the microorganisms associated with the mine tailings. The physiochemical analysis of tailings soil and water, HM species, and their carcinogenic and non-carcinogenic effects were determined. Heavy metal resistant bacteria (HMRB) were then isolated using nutrient agar supplemented with metals. The results showed that pH and temperature of the soil and water samples ranged between 6.2- 6.6 and 29–30 °C respectively. The estimated incremental lifetime cancer risk (ILCR) from one location was 7.9E − 6 was the highest. The HMs detected includes Arsenic (As), Mercury (Hg), Cadmium (Cd), and Lead (Pb). Twenty-one HMRB were isolated and they are putatively identified as Staphylococcus spp., Bacillus sp., Salinicoccus halodurans, Staphylococcus chromogenes, Paenibacillus cellulositrophicus, Paenibacillus residui, Sporosarcina globispora, and Streptococcus sp. Analysis of the 16S RNA genes sequences revealed that isolate MS2 has 98.01% similarity to Aneurinibacillus aneurinilyticus. The presence and levels of HMs elucidates the high risk of cancerous and non-cancerous effects borne by artisan gold miners. The isolated HMRB can be further analyzed for possible bioremediation of the site.

Mercury-resistant biofilm-forming bacteria and local plants in phytoremediation of small-scale gold mine tailings in Lombok Island, Indonesia

Small-scale gold mining is one of the sectors that contribute to the world's largest mercury contamination through the tailings it produces. Many efforts have been made to reduce mercury concentrations from tailings, one of which is by utilizing a combination of plants and bacteria. This study aims to analyze the combination of mercury-resistant biofilm-forming bacteria and local plants in the phytoremediation of small-scale gold mine tailings. This study used ten plant species divided into three groups and three biofilm-forming mercury-resistant bacteria (<em>Bacillus toyonensis</em>, <em>Burkholderia cepacia</em>, and <em>Microbacterium chocolatum</em>). Parameters observed included plant biomass, total chlorophyll, plant mercury content and media. The results showed that adding bacteria to each plant in the treatment had a different effect. Some plants with the addition of biofilm-forming bacteria had a higher wet weight than others. However, the addition of bacteria was not effective in increasing plant dry weight. The combination of biofilm-forming bacteria in the first and second plant groups reduced tailings mercury concentrations better than without the addition of bacteria. The combination of plants and bacteria in the third group gave higher media and plant mercury concentrations. This study shows that the addition of biofilm-forming bacteria can lead to increased remediation by plants. The second plant group treatment with a combination of <em>P. indica, P. conjugatum</em>, and <em>S. sesban</em> plants was the most effective in reducing tailings mercury content.

Mercury Removal and Gold Recovery from Artisanal Gold Mining Tailings Using Silver Electroplated Copper Plates

Mercury Removal and Gold Recovery from Artisanal Gold Mining Tailings Using Silver Electroplated Copper Plates

Diagnostic gold deportment studies and leaching behaviour of small-scale gold mining tailings from Eastern Region, Ghana

Artisanal and small-scale gold mining (ASGM) sector employs about 80% of the mining workforce but only contributes about 20-30% of Ghana’s gold production. The low gold production is linked to low recoveries associated with the activities because ofinadequate understanding of the chemical, mineralogical and metallurgical characteristics of the ores. This study examined the metallurgical characteristics of typical small-scale gold mining tailings to understand their grinding characteristics, gold deportment and cyanidation behaviour. The gold deportment results showed that 96.1% of the gold in the samples is free milling (can be leached directly with cyanide and recovered through carbon adsorption), whilst the remaining 3.9% of the gold in the samples is associated/locked up with other mineral phases (carbonates, sulphides, carbonaceous matter and quartz). The gold-by-size distribution also indicated that 73.1% of the gold is contained in coarser size fractions (+150 µm), 14.96% isfrom–150 µm to +75 µm size range, and 11.83% is contained in the finer size distribution (–75 µm). This suggests that incorporating a gravity recovery system during processing will be highly advantageous. The leaching kinetics results showed that gold recoveries achieved within 8, 16 and 24 h were 68, 73.8 and 76.4%, respectively. The corresponding total cyanide consumption rates after 8, 16 and 24 h of leaching were 550, 580 and 600 ppm, respectively. Generally, the gold recoveries and the cyanide consumption rates agree with industrial practices/results. Overall, the outcomes of the study support the view that some small-scale gold mining tailings are economically viable, and hence can be re-processed through efficient processes such as carbon-in-leach/carbon-in-pulp.

Environmental Impacts of Gold Mining—With Special Reference to South Africa

Gold mining has serious negative environmental impacts, especially due to pollution emanating from tailings storage facilities (TSFs, tailings dams, slimes dams). The most important forms of pollution from TSFs are acid mine drainage (AMD) and high levels of potentially toxic elements (PTEs). AMD arises from the high levels of pyrite in the mining ores, which become oxidised in the TSFs where the pyrite is exposed to atmospheric oxygen. The sulphate produced from oxidation of the sulphide in the pyrite dissolves in water to form sulphuric acid, a very strong acid. pH levels in the extremely low range of 3–4 are common. At such low pH the mobilities of numerous metallic PTEs present in gold mine tailings become extremely high, causing them to move into the environment in AMD. AMD acidifies soils to very low pH levels at which the mobility and plant-availability of metallic PTEs are very high, causing toxicities. Very disconcerting is that AMD and PTE pollution is in some cases continueing unabated at high rates even more than 70 years after a mine has been abandoned. Rehabilitation of TSFs to contain AMD and PTEs within them is very expensive and there seems to be reluctance to fully commit to their rehabilitation. Rehabilitation of TSFs is also extremely difficult. There does not yet seem to be any guidelines for their effective rehabilitation.