The expert panel on the mount polley disaster concluded that. Environmentally, the past 1015 years have experienced a very positive approach to improving the quality of effluents discharged from mining and milling processes, and ultimately the quality of seepage from the tailings impoundment area into the environment. Arsenic as and heavy metals may be released from the mine wastes to the ground and surface water systems, as well as the geological. The text is devoted to the many practical aspects of tailings management the concerns, the problems, the solutions where knowledge exists, and the presentation of a methodology to examine mine and metallurgical wastes for the ultimate objective of designing the best disposal option for that particular site. The microbial community composition was affected by temperature and the tailings used.
Tailings are the materials left over after the process of separating the valuable fraction from the uneconomic fraction of an ore. Water contaminated by the mining industry is also referred to as tailings. Tailings ponds a toxic legacy of albertas oilsands. Water management in oil sands mining facilities oil. Oil sands tailings ponds are engineered dam and dyke systems used to capture oil sand tailings. Literature from the results of two search engines using key words that contained oil sands tailings pond water, oil sands process water, and. Mar 30, 2017 showdown looming for albertas oilsands over cleanup of tailings ponds. Evaluation of microbial biofilm communities from an alberta oil sands tailings pond. Mine tailings size and composition depends on the mining method. Leachability of arsenic and heavy metals from mine. The alberta government is stepping up its plans to contain tailings ponds by introducing a new tailings pond framework in its.
Polymerdriven flocculation and dewatering of mature fine tailings mft is critical to improve their consolidation. New approaches for extracting and recovering metals from mine tailings. The mine tailing ponds, near the las moreras dry watercourse, are situated on. No current fine tailings treatment technology can completely eliminate tailings ponds, despite considerable efforts to address the slow settling of fines and to facilitate the consolidation of sediments. Water reclaimed from the tailings pond is over 99% water with up to 1% fine solids and trace amounts of hydrocarbons. Aug 10, 2018 tailings are a type of rock waste from the mining industry. In case of a power failure in the main building, the containment pond is. The chemical composition of tailings depends on the mineral. Most of the mines in korea have been closed since the 1970s due to various changes in the structure of the domestic industry. During this time, the tailings pond will be pumped to a low level to assist the tailings surface to gain strength. An early winter storm in 2010 forced birds to land on the toxic tailings ponds and nearly 550 of these ducks had to be destroyed this is the second. The composition of all tailing samples is characterized by the high contents of orebearing elements in each district. Tailings are the leftover material after the minerals that contain the elements of interest have been removed. Mine tailings out of those, in particular, act as a main source of environmental contamination.
Oil sands process water and tailings pond contaminant transport. Tailings turns out to be an apt title, not just for the beauty but also because tailings are toxic, veritably eternal, perfect symbols for the terrible beauty writers aspire to. Brilliant in all of its guises, tailings only makes me want to read more by kaethe schwehn. Oil sand tailings contain a mixture of salts, suspended solids and other dissolvable chemical compounds such as acids, benzene, hydrocarbons residual bitumen, fine silts and water. Tailing pond of the study area i the tailing pond of this type, where a spill channel is figure i location map of barsua iron ore mines. Every sentence in it glows like the orange remains of the mining process called tailings. Reserve began to deposit waste on an inland pond, a practice that continues with the companies that mine. Chemicals reaching tailings ponds may undergo further reaction.
At mount polley mp, the valuable elements are copper cu, gold au and silver ag and they are found most commonly in the sulphide minerals, chalcopyrite cufes 2 and bornite cu 5 fes 4. Geoenvironmental characterization of sulfide mine tailings. Below is a concept plan showing what the waste rock embankments may look like once rehabilitation is complete. Mft flocculation and dewatering depends on the size of the suspended clay particles, and on the composition and properties of the liquid in which they are dispersed. A tailings pond near the syncrude tar sands operations near fort mcmurray, alberta, on. Technological innovations in bitumen extraction and assisted tailings consolidation have resulted in more complex constituent compositions.
The influence of tailings composition on flocculation. The breach of a tailings pond at the mount polley copper and gold mine in b. Showdown looming for albertas oilsands over cleanup of tailings ponds. Tailings are a type of rock waste from the mining industry.
While the chemical composition of ospw has implications for industrial processes, including enhancement of bitumen recovery, treatment, water. These practices are now prohibited by state and federal laws. When tailings deposition ceases, there will be an initial period in which the water quality within the pond will require monitoring and treatment. The particles are transported along the settled tailings surface by siltation and rolling8. Review of the composition and toxicity of oil sands processaffected. Oil sands tailings ponds are engineered dam and dyke systems used to capture oil sand.
Earthen tailings impoundment dam at fort knox gold mine in alaska. Tailings ponds a toxic legacy of albertas oilsands the star. The chemical composition of tailings depends on the minerals mined and the extraction technique. Current knowledge of seepage from oil sands tailings ponds and its. The chemical composition of tailings depends on the minerals mined and. Biomass production on reclaimed areas tailing ponds. Samples for this project were collected from the pond areas of two impoundments, and from the tailings delivery slurry. Nov 17, 2009 furthermore, as and heavy metals from mine tailings may cause fatal diseases in humans through crops and water due to the characteristic easy accumulation in internal organs. The tailings pond is eventually drained and the tailings are disposed in a big stack of dry sand. The biggest problem with all this is wateri suspect thats the problem here.
Minimization of operating pond levels independent expert panel recommendations where should i go if i want to know more about tailings facility design and operations. Large volumes of tailings are a byproduct of bitumen extraction from the oil sands and. Certain types of extraction process, like heap leaching for example, may result in quantities of chemicals used to perform the leaching remaining in the material once leaching has been completed. Groundwater pollution in one portion of the coeur dalene mining district results from leaching of old jig tailings that are intermixed with the upper part of a sand and gravel aquifer. The olympic dam tailings solids particles have a specific gravity around 3. It is not always possible to select and control construction of the material overlying subsurface drains in tailings impoundments. Are tailings storage facilitiesdams the same as conventional water dams.
These effects should be studied for each type of tailings solution before use of the sealant in the holding pond. Planning, design, and analysis of tailings dams vick, steven g. Showdown looming for albertas oilsands over cleanup of. Paste tailings is a modification to the conventional methods of disposal of tailings pond storage. Tailings management at nrcan natural resources canada. The reclaim pond s or return pond s store the water that is being decanted from the tmf. Sep 02, 2014 tailings from bitumen mining are a mixture of water, sand, and fine clay, and also contain residual bitumen. She writes with fierce intelligence and luminous clarity on all of her subjects. The composition of this manmade material and its influence on the insitu state of tailings is of particular importance. This book assembles all the various aspects of the process and of tailings management which have an impact on the. The solids are generally composed of very fine clays that do not settle easily in the tailings pond. Leachability of arsenic and heavy metals from mine tailings.
Some treatments use coagulants and coarse solids to form composite or consolidated tailings. Tailings are stored in engineered structures called tailings impoundment areas, which can be created through the use of dams, berms, and natural features of the mine site such as valleys, hillsides, or depressions. Reclaim ponds are sometimes referred to as decant ponds which in most parts of the world is another name for the supernatant pond. The tailings pond is a necessary facility for maintaining normal production of a mine as a place for stockpiling tailings. For hardrock metal mines, tailings are usually a very fine mud or powder, which is left over after ore is crushed and valuable minerals are extracted from it. A geosynthetic protection system was required to protect the slopes and floor from the water, prevent contamination of the surrounding area and withstand heavy equipment. A reclaim pond is situated outside the confining walls of the tailings storage area a short distance away figure 7.
An early winter storm in 2010 forced birds to land on the toxic tailings ponds and nearly 550 of these ducks had to be destroyed this is the second time syncrude has been in the news in relation. In the past, mill tailings have been discharged onto hillsides or directly into lakes or streams. Once the ore has been stripped of its valuable minerals, sometimes through the addition of chemicals, it is piled up into tailings. Help get the word out about our report showing that albertas toxic oil sands tailings ponds are growing and the costs to clean them up is rising. A research program was therefore initiated at the university of pretoria, to investigate the composition and state of south african gold tailings on the far west rand gold reefs.
This value range reflects the typical acid character of stored mine tailings. So the tailings are processed to take out the suspended solids found in the water. Characteristics of the iron ore tailing pond effluent in. Tailings contain waste from the extraction processes such as equipment wash water, and from the refining process, often discharged in the form of slurry, which is a mix of fine gangue particles, chemicals and water, to large retention facilities called tailing dam or tailing ponds. Tailings are distinct from overburden, which is the waste rock or other material that overlies an ore or mineral body and is displaced during mining without being processed. Water rises to the top, while heavier materials such as metals and minerals settle at the bottom of the pond.
Tailings is a beautiful and original book by a remarkable writer. The reclaim ponds or return ponds store the water that is being decanted from the tmf. Tailings may also contain chemicals used for mineral extraction. The composition of the tailing was essentially pyrite 63.
Mining operations generally produce many types of mine wastes, including mine tailings, waste rock and slag. This paper deals with the behaviour in a tailings pond of the residues produced during the flotation of a complex sulphide ore. Now imagine that pit filled with up to 10 billion tons of tailings waste thats derived from. Water systems in modern mines are complex and an understanding of the tailings pond and plant water balance is necessary.
Tailings ponds up close oilsands miners are making progress in their efforts to shrink their tailings ponds and are being prodded to quicken their pace by a regulators recent rules, say tailings technology researchers. Today, the universal disposal method for tailings is the tailing pond. Responsible tailings management needs to consider the specific characteristics of tailings. Biomass production on reclaimed areas tailing ponds intechopen. The expert panel on the mount polley disaster concluded that the design of the tailings pond was. Now imagine that pit filled with up to 10 billion tons of tailings waste thats derived from mining that will remain there forever. When a mineral product is mined, the valuable portion is usually embedded in a rock matrix called ore. The composition of tailings is directly dependent on the composition of the ore and the process of mineral extraction used on the ore. New approaches for extracting and recovering metals from. In addition, sulphite ion and other thiosalts were present in the liquid phase. Tailings storage 2 was decommissioned for tailings deposition in 2005.
This selection and control can at best be done by cycloning the tailings material in the direct vicinity of the drains. Conventional tailings slurries are composed of a low percent of solids and relatively high water content normally ranging from 20% to 60% solids for most hard rock mining and when deposited into the tailings pond the solids and liquids separate. Over the past several years, the freshwater fisheries society of bc has delivered learn to fish programs for youth and their families, as well as participated. Tailings pond water is recycled for use as process water throughout the bitumen extraction plant. Tailings are slurried with water and pumped to tailing ponds for settling. The nerco victor project had a acre tailings pond with a subbase of coarse tailings covered by a 20 mil pvc liner. This slender memoir will stick with you much longer than many bulkier books. Control of the water balance can avoid problems such as operating losses from water shortages or hazardous releases as a result of a water surplus. These tailings are drained into settling ponds where sedimentation separates the ingredients. Grey tailings are stored in the tailings pond shown to the left of the darkcoloured berkeley pit. Dec 27, 2012 these methods can be applied with wetlands and wet landscape approaches aimed at reclaiming tailings as a land surface or a wetland.
Hazards and opportunities investing news network october 4th, 2015 tailings from gold mining operations can pose a threat to the environment and health of. However, leakage from the pond and water from the pond s decant system combine with natural ground water to compound the problem by raising the water table into old jig tailings which cover the upper portion of the aquifer. This chapter presents the results of a multiannual systematic research and development of essentially new environmental safety technology of overlapping tailing pond modelled in terms of vojany thermal power plant evo, slovakia. Reserve began to deposit waste on an inland pond, a practice. A tailings storage facility tsf is a structure one or more dams built for the purposes of storing the uneconomical ore ground up rock, sand and silt and water from the milling process. These methods can be applied with wetlands and wet landscape approaches aimed at reclaiming tailings as a land surface or a wetland. Structuralenvironmental characteristics of tailings ponds. The pond had a 12 inch compacted foundation and liner bedding in 2 inch lifts. Drainage was picked up by a coarse gravel material over the composite liner along with perforated pipe. Tailings ponds up close canadian mining journalcanadian. The trojan pond reclamation site has become an excellent community resource for environmental education and outdoor recreation. Hazards and opportunities investing news network october 4th, 2015 tailings from gold mining operations can pose a threat to the environment and health of nearby communities. New approaches for extracting and recovering metals from mine. The authors are grateful to carlos frias, at cobre las cruces s.
Tailings from bitumen mining are a mixture of water, sand, and fine clay, and also contain residual bitumen. An investigation of the use of inline thickened tailings to create composite tailings at a sand to fines ratio, sfr, of 4. The mineralogical composition of tailings, colluvial, watercourse sediments, and. For example, cyanide compounds have been used in some gold au. In general, the sealing character istics for tailings ponds should be the same except for the effect of chemical constituents in the tailings pond solutions on the sealant.
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