Acid mine drainage (AMD) contains high concentrations of heavy metals …
WhatsApp: +86 18221755073
Acid Mine Drainage. Evans, Thomas 1 ; Reese, Michael 2. Acid Mine …
WhatsApp: +86 18221755073
CHEMICAL ASPECTS OF ACID MINE DRAINAGE H. L. Barnes and S. B. Romberger Water pollution by acid mine drain age has ruinous effects which have limited severely or destroyed the pro ductivity of large parts of Appalachia and other areas. Lovell (1) has esti mated that such drainage pollutes 5,000 miles (8,000 km) of streams in
WhatsApp: +86 18221755073
ACID MINE DRAINAGE (AMD) MANAGEMENT 285 Acid Mine drAinAge (AMd) MAnAgeMent r.W.gAikWAd*And d.V. guptA * Department of Chemical Engineering, Pravara Rural Engineering College, Loni, Dist. Ahmednagar 413 736, M.S., India ** University School of Chemical Technology, GGS Indraprastha Universi-ty, New Delhi …
WhatsApp: +86 18221755073
Alkalinity ¾Capability of water to neutralize acid ¾Important to aquatic life ¾Buffers against rapid pH change ¾Often related to hardness ¾Hardness is the concentration of divalent cations (e.g., Ca2+, Mg2+) ¾Water-quality criteria for some metals are hardness-dependent ¾In mining impacted systems, Ca2+, Mg2+, etc. can originate from the weathering of a …
WhatsApp: +86 18221755073
Acid mine drainage induced by the mining industry causes environmental and economic issues. Acid mine drainage contains mainly metals such as Fe, Al, Cu, Ca, Mg, Mn and Zn. Preventing the formation of acid mine drainage has not been found feasible. As a consequence, remediation treatments have been developed during the …
WhatsApp: +86 18221755073
Acid Mine Drainage (AMD) occurs when surface and groundwater pass through heavy metal or coal mines. More often than not, mines that produce acid mine drainage are abandoned mines that have not been properly maintained. ... (Equation 1) 4 Fe 2+ + O2 + 4 H+ -> 4 Fe3+ + 2 H2O (Equation 2) 4 Fe3+ + 12 H2O -> 4 Fe(OH)3 + …
WhatsApp: +86 18221755073
Formation mechanism and environmental impact of acid mine drainage2.1. Formation mechanism of acid mine drainage. The formation process of AMD is the oxidation process of sulfide minerals, which is completed by chemical oxidation and biological oxidation. Biological oxidation plays a decisive role (Kefeni et al., 2017).
WhatsApp: +86 18221755073
The acid mine drainage (AMD) that is formed can have an impact on physical, chemical, biological, ecological, and socio-economic conditions. AMD has a pH range of 2 to 5 and can result from coal ...
WhatsApp: +86 18221755073
The prediction of mine drainage can be conducted using chemical and/or mineralogical static tests and/or kinetic tests. Static tests provide a simple and rapid overview of the type of mine drainage by comparing the neutralization and acidification potentials. However, static tests may show contradictory results for the same sample.
WhatsApp: +86 18221755073
Acid mine drainage (AMD) is a worldwide concern in coal and metal …
WhatsApp: +86 18221755073
The pollution loads in surface waters, streams and rivers draining the Witwatersrand gold mining region were previously assessed and the impact of the spatial distribution, seasonality, and chemical processes of these AMD waters are well understood (Davidson, 2003, Marsden, 1986, Tutu et al., 2008).The South African Department of …
WhatsApp: +86 18221755073
The chemical reactions in acid mine drainage produce acidic water and an orange precipitate. The chemical equations of these reactions are shown below. Oxidation of ferrous ions in pyrite: {eq}Fe^{2+}(aq) + O_2(g) + 4H^+(aq) to Fe^{3+}(aq) + 2H_2O {/eq}
WhatsApp: +86 18221755073
Acid mine drainage (AMD) is created when iron–sulfur compounds come into contact with atmospheric oxygen and water. Through a series of chemical and biochemical reactions, a solution with low pH, high mineral acidity, and elevated dissolved metal (e.g. iron, aluminum, magnesium) concentrations is produced.
WhatsApp: +86 18221755073
Stream impacted by acid mine drainage from a Mid-Atlantic abandoned coal mine. acid mine drainage (the most prevalent; see below), alkaline mine drainage (this typically occurs when calcite or dolomite is present), metal mine drainage (high levels of lead or other metals drain from these abandoned mines). Acid mine drainage is the …
WhatsApp: +86 18221755073
First, the pyrite is oxidized to ferrous sulfate via the action of excess water and molecular oxygen (eq 1), which is a critical reaction for AMD generation.Subsequently, the Fe 2+ is oxidized to Fe 3+ (eq 2); this step is usually a slow process, which is considered a "rate-determining step".Then a part of Fe 3+ is precipitated as Fe(OH) 3 …
WhatsApp: +86 18221755073
Acid mine drainage is often recognised by the presence of bright orange water and …
WhatsApp: +86 18221755073
Mine drainage is surface water or groundwater that drains from an active or abandoned mine. In some cases, pyrite (an iron sulfide mineral) is exposed and reacts with air and water to form sulfuric acid and dissolved iron. Some or all of this iron can precipitate to form the red, orange, or yellow sediments in the bottom of streams containing mine drainage.
WhatsApp: +86 18221755073
For instance, coal mine wastes in addition to artificial irrigation leached acid drainages contains high concentrations of Pb, Fe, Cr and SO 4 2− etc. which reflects a typical acid mine drainage. Some of the metal sulfides and their chemical formula are shown in Table 1 .
WhatsApp: +86 18221755073
Acid Mine Drainage Prediction Acid mine drainage prediction tests are increasingly relied upon to assess the long-term potential of acid generation. This concern has developed because of the lag time at existing mines between waste emplacement and observation of an acid drainage problem (Univ. of California, Berkley 1988). The issue of
WhatsApp: +86 18221755073
Acid mine drainage (AMD) is perhaps one of the most relevant challenges the mining industry has faced during the last few decades. This issue is particularly important in the scenario of mine …
WhatsApp: +86 18221755073
Acid mine drainage (AMD) or acid rock drainage (ARD) refers to the effluents from coal and metal mines. AMD is a common phenomenon which occurs naturally as a process of rock weathering, but is increased in large scale due to human activities such as construction contracts (transportation corridors, dam build, etc.) and mining operations.
WhatsApp: +86 18221755073
Acid mine drainage can release toxic levels of heavy metals into the environment. Learn about its causes, environmental impact, and possible solutions ... The chemical reaction forms sulfuric acid ...
WhatsApp: +86 18221755073
This paper describes Acid Mine Drainage (AMD) generation and its associated technical issues. As AMD is recognized as one of the more serious environmental problems in the mining industry, its causes, prediction and treatment have become the focus of a number of research initiatives commissioned by governments, the …
WhatsApp: +86 18221755073
In abandoned open-pit coal mines, surface water and groundwater form acidic waters with high concentrations of metal ions due to chemical interactions with ores such as pyrite, and the formation of acid mine drainage (AMD) is one of the major sources of pollution of world concern. For this reason, this paper reviews the formation …
WhatsApp: +86 18221755073
The overall process of acid drainage (also referred to as acid mine drainage—AMD, or acid rock drainage—ARD ) is the chemical response to acid-producing and acid-consuming weathering reactions (Lottermoser 2010). The individual parameters significantly governing sulfide oxidation are described in this chapter for the …
WhatsApp: +86 18221755073
The redox reaction in this acid mine drainage can be summarised by the equation (as yet unbalanced): FeS ... How can you work out what the chemical formula of this mineral is? Solution is to divide each weight by its atomic weight: Cu 63:31=63:5 ˙ …
WhatsApp: +86 18221755073
Acid mine drainage (AMD) frequently results from extensive excavations that expose sulphide minerals to form acidic substances and flow into the stream. ... The chemical equation for this first step is as follows. In the process, each mol of oxidation of pyrite will contribute to 2 moles of hydrogen ion. $$ { Fe S}_2kern0.5em left(mat{s ...
WhatsApp: +86 18221755073
Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. …
WhatsApp: +86 18221755073
1. Introduction. Acid mine drainage (AMD) is a severe environmental problem associated with mining activities. AMD has been recently named the second most important global concern after global warming by the United Nations, highlighting the significance of this environmental challenge (Vasquez et al., 2022).AMD is produced …
WhatsApp: +86 18221755073
1. Introduction. Acid mine drainage (AMD) is a major problem all over the world, especially where coal and gold mine activities are common. Once AMD is generated, it is difficult to control the process and the treatment also requires high cost (Aguiar et al., 2016, Baruah and Khare, 2010, Grande et al., 2010, Qureshi et al., 2016).AMD causes …
WhatsApp: +86 18221755073حقوق النشر والنسخ؛ 2024.Aava جميع الحقوق محفوظة.خريطة الموقع