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 ...
hanna, g.p., acid mine drainage research potentialities, journal water pollution control federation 35: 275 (1963 ... scholar. huffmann, r.e., kinetics of the ferrous iron-oxygen reaction in sulfuric acid solution, journal of the american chemical society 78: 4836 (1956). google scholar. lorenz, w.c., u.s. bureau of mines information circular ...
1. 2FeS 2 + 7O 2 + 2H 2 O -> 2FeSO 4 + 2H 2 SO 4. 2. 2Fe 2+ + 1/2 O 2 + 2H + -> 2Fe 3+ + H 2 O. 3. Fe 3+ + 3H 2 O -> Fe (OH) 3 + 3H +. 4. FeS 2 (s) + 15/4 O 2 + 7/2 H 2 O <--> 4H + + 2SO 4- +Fe (OH) 3 (s) Production of acid mine drainage can …
General equations for this process are: 2FeS 2- 2 + 7O 2+ 2H2O → 2Fe2+ + 4SO + …
This water is referred to as acid and metalliferous drainage (AMD) or acid rock drainage (ARD). AMD/ARD can display one or more of the following chemical characteristics: Low turbidity or total suspended solids (TSS) (combined with one or more of the above). The generation of AMD/ML/ARD is the primary geochemical risk associated with most mine ...
4.4.3.6.6 Acid Mine Drainage Water. AMD is caused by natural oxidation of metal sulfides to metal sulfates. AMD is low in pH and consists of soluble toxic metals (such lead, copper, cadmium, arsenic, and other metals), causing pollution of aquatic systems. Cheng et al. [81] used acid mine drainage fuel cell AMD-FCs, which were structurally ...
PROBLEM SOLVING 2. CHEMICAL REACTIONS AND EQUILIBRIA 1 2.2Acid mine drainage Problem2.2 The weathering of iron sulphide minerals produces acidified water, leading to major environmental problems from abandoned metal and coal mines. If the water is then diluted or neutralised such that the pH is raised su ciently, a
Acid Mine Drainage: The major environmental concern related to the mining industry is acid mine drainage. It has a significant impact on wildlife and aquatic life. It causes water and soil pollution. Ultimately {eq}rm H_2SO_4 {/eq} will be generated during this process. Answer and Explanation: 1
The generation of acid mine drainage (AMD) and release of water containing elevated concentrations of metals from mine wastes is an environmental problem of global scale. AMD is caused by the oxidation of sulfide minerals in the mine waste that occurs when these materials are exposed to atmospheric oxygen (O2). ... (equation 2) generating ...
** University School of Chemical Technology, GGS Indraprastha Universi-ty, New Delhi 110 006, India key words : Acid mine Drainage, Environmental Effects, Treatment . ABStrAct AMd is recognized as one of the most serious environmental problem in the mining industry. the problem of acid mine drainage (AMd) has been present since …
dissociated sulphuric acid. You can see from equation (1) that in order for these reactions to happen, the pyrite must be exposed to both air and Mining is one of South Africa's most important industries, but it comes with a cost. Rebecca Garland explains about acid mine drainage. Acid mine drainage – the chemistry
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 …
Definition. Acid mine and acid rock drainage (AMD/ARD) refer to the extremely acidic (pH < 3), metal-rich waters that are derived from the weathering of sulfidic minerals when exposed to air, water, and microorganisms (Figure 1; Nordstrom and Alpers, 1999; Bond et al., 2000 ): Acid Rock Drainage. Figure 1. An AMD stream at a nickel-copper mine ...
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 …
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 ...
An introduction to acid mine drainage. Iron pyrite, FeS2, also known as 'fool's gold', is the most important source of nearly all water pollution originating from mines and their residue deposits. When pyrite is exposed to air and water, it oxidises to form sulphuric acid and iron oxides and hydroxides ('yellow boy'), which causes the pH of th ...
Pyrite is the mineral of most relevance from an acid-generation perspective, because its concentration, grain size and distribution may be the most important factors affecting the production of acidic mine waters (Nordstrom and Alpers 1999).Other sulphides commonly found in ore deposits are listed in Table 2 (Plumlee 1999).These sulphides …
Life Cycle Analysis of Power Generation Systems. Joule Bergerson, Lester Lave, in Encyclopedia of Energy, 2004. 4.6.2 Acid Mine Drainage. Acid mine drainage is the main cause of polluted water in the United States with devastating effects on biological activity in many streams. In 1995, 2400 of 54,000 miles of streams in Pennsylvania were polluted …
July 1, 2016. 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.
Acid mine drainage (AMD) contains high concentrations of heavy metals and sulfates with strong acidity. AMD exists in several major coal-producing countries such as China, the United States, Canada, etc., and it poses significant threaten to the environment and human health owing to it exists in nature for a long time and continues …
The reactions of acid generation are best illustrated by examining the …
Mine drainage forms from a chemical reaction between water and rocks containing sulfur-bearing minerals. The resulting waters become rich in sulfuric acid and dissolved iron. ... Acid mine drainage can change the color of a stream into red or orange. Mine drainage refers to any surface water or groundwater that drains from an active or ...
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 + …
Acid Mine Drainage Definition. Acid mine drainage refers to the acidic water that forms when surface water (which can mean rainwater, snowmelt, pond water, etc.) and air are exposed to iron ...
Abstract. Acid mine drainage (AMD) frequently results from extensive excavations that expose sulphide minerals to form acidic substances and flow into the stream. If untreated, the continuous oxidation of AMD may be severe in the ecological system with heavy metal pollution. One of the most significant challenges for the modern …
Acid Mine Drainage Overview. Acid rock drainage (ARD) is produced by the oxidation of sulfide minerals, chiefly iron pyrite or iron disulfide (FeS2). This is a natural chemical reaction which can proceed when minerals are exposed to air and water. Acidic drainage is found around the world both as a result of naturally occurring processes and ...
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 …
Acid mine drainage (AMD) is a worldwide concern in coal and metal mining. Mine planners must predict AMD potential before disturbance. If AMD is predicted, planners must install control measures such as spoil handling plans, alkaline amendment, and covers. Treatment of AMD uses chemicals such as Ca (OH) 2, CaO, NaOH, Na 2 CO 3, …
Abstract. 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.
Acid mine drainage (AMD) is the acidic water produced when rock containing sulphide minerals comes into contact with water and oxygen. Besides having a low pH, such water often contains high concentrations of dissolved solids, and often poses a serious threat to groundwater quality which, in turn, can affect drinking water; 1 AMD destroys aquatic life …
Regular monitoring of Acid Mine Drainage (AMD) is essential for understanding its extent and impact on water resources. Traditional manual sampling methods have limitations, such as limited representativeness and delayed lab analysis. High-frequency monitoring offers an alternative, enabling real-time analysis of AMD …
Abstract. Acid mine drainage (AMD) or acid rock drainage (ARD) is considered as one of the main pollutants of water in many countries that have historic or current mining activities. Its generation, release, mobility, and attenuation involves complex processes governed by a combination of physical, chemical, and biological factors.
metal mine drainage (high levels of lead or other metals drain from these abandoned mines). Acid mine drainage is the formation and movement of highly acidic water rich in heavy metals. This acidic …
The chemical characteristics of acid mine drainage with particular reference to sources, distribution and remediation: the Witwatersrand Basin, South Africa as a case study Appl. Geochem., 23 ( 2008 ), pp. 3666 - 3684
Acid mine drainage (AMD) represents a major problem in the mining industry worldwide due to the risk of water and soil pollution. Its active treatment involves the addition of alkaline reagents such as NaOH or Ca(OH) 2 to increase the pH and precipitate the dissolved metals, although substantial amounts of dissolved ions might …