When fully exposed to air and water, the chemical reactions forming amd occur at a faster rate. Acid mine drainage control technologies are measures that can be undertaken where. Acid rock drainage ard is a natural process whereby sulphuric acid is produced when sulphides in rocks are exposed to air and water. Acid mine drainage amd is a problem occurring across the globe, including in southeastern ohio. The area of pond 2 that is below the finished surface level refer figure 6 drawing 4. Characteristics increased acidity decreased ph increased metal concentrations increased sulfate increased suspended solids all.
There are four chemical reactions that represent the chemistry of pyrite weathering to form acid mine. Acid mine drainage amd is typically characterized by low ph and high dissolved iron. Rocks stained by acid mine drainage on shamokin creek. Acid rock drainage some bedrock contains minerals that can generate acid rock drainage ard. A global crisis acid drainage is a littleknown global crisis. Geological survey usgs in 2003 with the objective of better understanding geologic, geochemical, and hydrologic controls on naturally occurring acid. Most rock extraction sites, including mine sites and building construction sites, require a plan to assess, and mitigate if present, the risk of acid mine drainage amd.
Unexpected nonacid drainage from sulfidic rock waste. Acid mine drainage overview acid rock drainage ard is produced by the oxidation of sulfide minerals, chiefly iron pyrite or iron disulfide fes2. Acid rock drainage treatment using membrane distillation. Acid rock drainage ard is produced by the oxidation of sulfide minerals, chiefly iron pyrite or iron. Acid rock drainage from sulphide minerals is the most significant environmental impact from mines.
The most significant environmental impact from mines results from minerals that weather and release potentially harmful elements into water resources. Pdf acid mine drainage amd occurs after mining exposes metal sulfides to. What can be done to prevent or clean up acid mine drainage. As part of the superfund innovative technology evaluation site program, an evaluation of the compostfree bioreactor treatment of acid rock drainage ard from the aspen seep was conducted at the leviathan mine superfund site located in a remote, high altitude area of alpine county, california. Acid rock drainage ard, also referred to as acid mine drainage amd, is the outflow of acidic water from mining operations including waste rock, tailings, and exposed surfaces in open pits and underground workings. In this lecture we discuss weathering, acid rock drainage and methods for prevention and mitigation. The formation of acid mine drainage and the contaminants associated with it have been described as the largest environmental problem facing the u. Compostfree bioreactor treatment of acid rock drainage.
Illustrated with dozens of photographs, charts, tables and maps, the book is a compendium of 36 scientific papers written by. The global acid rock drainage guide pdf about 126 mb. An in situ ftir study of galena and pyrite oxidation in aqueous solution. Problems associated with mine drainage contaminated drinking water disrupted growth and reproduction of aquatic plants and animals corroding effects of acid on parts of infrastructure such as bridges acid mine drainage mines built as early as the 1800s were developed in a manner which utilized gravity drainage, to avoid excessive water accumulation in the mines. Acid rock drainage analysis and testing services acid rock drainage ard also known as acid mine drainage amd describes the formation of acid when sulphidebearing mine wastes principally pyrite, but also pyrrhotite and chalcopyrite are exposed to oxidising conditions, typically in the presence of water, due. The mine is located on the eastern slope of the sierra nevada at about 7,000foot 2,100 m elevation, 6 miles 9. Comparison of acid rock drainage factors in waste rock piles and tailings.
Major environmental incidents caused by acid mine drainage. The mine site comprises approximately 250 acres 100 ha of. Pdf acid mine or acid rock drainage jorge g ibanez. Acid mine drainage terms acid mine drainage amd water that is polluted from contact with mining activity acid rock drainage ard natural rock drainage that is acidic both produce acidic waters how to distinguish. This is a natural chemical reaction which can proceed when minerals are exposed to air and water.
The following is an overview of information on some major. Sgs laboratories offer complete ard testing services that help predict acidic effl uents. Aerobic bacterial pyrite oxidation and acid rock drainage. If constructed correctly, olcs should be maintenance free and provide amd. Pdf acid mine drainage formation, control and treatment. The major areas of research on amd are prediction of amd and preventionmitigation. Yellow boy in a stream receiving acid drainage from surface coal mining. Acid mine drainage amd forms when sulfide minerals are exposed to oxidizing. This acid leaches out metals in the rock, which can enter nearby. Acid mine drainage prediction compares acid rock drainage factors of waste rock piles and tailings impoundments.
Acid mine drainage, rock drainage, and acid sulfate soils wiley. Acid mine drainage solutions for the mineral industry. Compostfree bioreactor treatment of acid rock drainage leviathan mine, california innovative technology evaluation report national risk management laboratory office of research and development u. Acid mine drainage mines built as early as the 1800s were developed in a manner which utilized gravity drainage, to avoid excessive water accumulation in the mines as a result, water polluted by acid, iron, sulfur and aluminum drained away from the mines and into streams results of acid mine drainage. Also learn about the impact of construction projects on this phenomenon. Ard is often mislabelled amd or acid mine drainage too. Acid rock drainage ard is the natural result of oxidizing or rusting of certain types of sulfurbearing minerals in the presence of water, air and bacteria. The ph scale actually measures hydrogen ion concentration in water solutions. Field testing methods to improve sampling for acid rock drainage assessments.
Acid rock drainage management plan kinnears quarry v2. Cleanup on most sites will take decades those with acid drainage will require water treatment in perpetuity. While most mines do not have an ard problem, the few that do represent a signi3cant liability for their owners as indicated in many of. Acid mine drainage research acid mine drainage amd has been the subject of intensive research since the 1960s. Acidic mining lakes acid mine drainage, limnology and. By far the most common mine drainage problem is that of acid mine drainage amd. Field testing methods to improve sampling for acid rock. A bench scale evaluation of organic substrates for use in constructed wetlands for the treatment of acid mine drainage 1991 197432284. The gard guide was created through the contributions of many individuals and organizations.
In examining this table, it is important to note that diffusion of oxygen into water is slow and, therefore, oxidation of iron sulfide is inhibited until the water level drops, which can occur periodically or seasonally in some cases. So, to better understand amd and ard, lets begin by defining some terms like ph the standard measure of acidity. The handcart gulch research site was developed by the u. Learn about how acid can naturally be generated from rocks exposed at the earths surface.
Ministry of energy and mines and ministry of environment, lands and parks, july 1998 table of contents 1. Infield geochemical testing has the power to significantly reduce the time taken for laboratory testing and can result in. Preventing acid and metalliferous drainage department of industry. Acid rock drainage as a concern and part of all metals and mining operations. View table of contents for acid mine drainage, rock drainage, and acid sulfate soils. Acidrock drainage at skytop, centre county, pennsylvania.
Preventing impacts from metal leaching and acid rock drainage mlard is a highly important, costly and timeconsuming environmental issue facing the british columbia mining industry. Acid mine drainage, acid and metalliferous drainage amd, or acid rock drainage ard is the. Acid rock drainage ard prediction is a very important issue in order to predict and prevent environmental pollution associated with mining activities. Acidrock drainage at skytop, centre county, pennsylvania, 2004. Media in category acid mine drainage the following 51 files are in this category, out of 51 total. Geological survey openfile report 20051148 online version 1.
Acid rock drainage analysis and testing services acid rock drainage ard also known as acid mine drainage amd describes the formation of acid when sulphidebearing mine wastes principally pyrite, but also pyrrhotite and chalcopyrite are exposed to oxidising conditions, typically in the presence of. This research focuses on a novel method of ard treatment. Acid rock drainage ard, also referred to as acid mine drainage amd, is the outflow of acidic water from mining operations including waste rock, tailings. The problem of acid rock drainage acid rock drainage ard, often referred to as acid mine drainage ard, can be defined as the drainage that occurs as a result of natural oxidation of sulphide minerals contained in rock which is exposed to air and water. The concentration of free hydrogen ions acid in solution is measured by ph. Leviathan mine is a united states superfund site cerclis id. Although ard impacts 12,000 miles of rivers in the u.
The potential risk of contaminated mine drainage should be fully evaluated before mining. Crush coarse rock samples such that at least 90% of the. This pdf of the gard guide can be downloaded and printed. Policy for metal leaching and acid rock drainage at minesites in british columbia. Acid mine drainage formation, control and treatment. Research efforts have proceeded recently through the acid drainage technology initiative. Water flowing through active or abandoned mine sites can become polluted by the material being mined1. Provincial policy and guidelines for mlard are available for proponents below.
Cost 1 mitigation measures are required when there is a need to prevent metal leaching or acid rock drainage impacts to other resources. Development of the global acid rock drainage guide. Pdf acid mine drainage control and treatment researchgate. Nowadays, simple tests are widely applied and established in the mining and consulting business for ard prediction. Sulfuric acid is produced when water interacts with sulfurbearing materials in the presence of oxygen and common bacteria1. Acid mine drainage amd forms when sulfide minerals, particularly pyrite and marcasite, have been exposed to oxidizing conditions during mining and other excavation activities, such as highway. Pdf after performing this experiment, the student shall be able to. Mine planners must predict amd potential before disturbance. Acid mine drainage prevention and control options nural kuyucak golder associates ltd. The development of the global acid rock drainage gard guide is sponsored by inap with the support of the global alliance. Acid mine drainage amd is a worldwide concern in coal and metal mining. Characterization of limestone reacted with acidmine drainage pdf.
The acidic water formed by this process can dissolve many metals in. By james tuff and brent usher, klohn crippen berger ltd, brisbane, australia. Free oxygen appeared in earths atmosphere for the first time around 2. Acid rock drainage ard is a metalrich wastewater that forms upon oxidation of sulfidic minerals. The acid mine drainage may also contain high amounts of co2 which forms carbonic acid and further depresses the ph. Cad98067685 at an abandoned openpit sulfur mine located in alpine county, california. Acid mine drainage amd is essentially the same process, greatly magnified. Acid mine drainage, rock drainage, and acid sulfate soils. Epa 600 modified sobek sample paste p h total s % acid. Pure neutral water has a ph of 7, acids have a ph less than 7 and.