Pyrite, or fool's gold, is a common mineral that reacts quickly with oxygen when exposed to water or air, such as during mining operations, and can lead to acid …

In this work, polyacrylamide functionalized chitosan polymers (CS-PAMs) of different structural properties were synthesized and investigated as selective depressants of pyrite (FeS 2) in the flotation process of galena (PbS) and chalcopyrite (CuFeS 2) from a complex sulfide ore.Response surface methodology (RSM) with a Box-Behnken design …

Cyanide is used in many mining plants, but its use has been questioned due to safety and environmental issues. This is because the xanthate and cyanide ions compete for the surface of pyrite, as occurs with the hydroxyl ion. The pyrite surface is covered by the Fe(CN) 6 4− ion according to the following reaction (Equation (20)) . In …

The decrease in surface hydrophobicity of pyrite particles during grinding is mainly due to two factors: (1) oxidation of pyrite surfaces by dissolved oxygen or Fe 3+ ions and (2) precipitation and adsorption of iron hydroxides/oxyhydroxides onto pyrite surfaces derived from grinding media as a result of galvanic interactions. It is generally ...

Depending on the location and scale, mining methods may include open-pit mining or underground mining. Open-pit mining involves removing the overburden and extracting pyrite from the exposed ore body. Underground mining, on the other hand, …

The mining and ore processing of sulfide-bearing deposits generates large volumes of waste rock (WR) and tailings, which often contain barren and residual iron sulfides (e.g., pyrite and pyrrhotite). Sulfide oxidation under atmospheric conditions can generate acidic leachates loaded with high concentrations of dissolved metal( oid )s …

The grinding process plays a crucial role in the floatability of mineral. The present study proposes a scheme to assist in the flotation separation of galena and pyrite by optimizing the choice of grinding media. The effects of grinding media (cast iron balls, steel balls containing 18% chromium, and steel balls containing 12% chromium) on the …

Pyrite oxidation in Na 2 CO 3 /NaHCO 3 solutions results in particles that are initially covered by a discontinuous oxide coating that grows with reaction time, thus increasing the overall pyrite surface coverage. In this case, a precipitation confined to the solid/liquid interface is favored by the higher ionic strength of the sodium carbonate ...

In 1997 Newmont USA Ltd. introduced the N 2 TEC process for the flotation recovery of auriferous pyrite and other sulfide minerals in Carlin type ores, using nitrogen as the flotation gas, and low pH to prevent oxidation and hydrolysis of the pyrite surface. However, increased amounts of carbonate gangue minerals in certain Carlin type ores …

Acid mine drainage (AMD) is a key concern of the mining industry due to its impact on the quality of water and soils surrounding mine waste deposits. Acid mine drainage derives from the oxidation of metal sulphides, e.g. pyrite (FeS 2), exposed to oxygen and water. The leachate acidity is capable of releasing heavy metals contained in …

The simulation results suggest that the variable flow rate in the vertical direction significantly enhances the pyrite oxidation near the ground surface. Peak concentration of Fe2+, Fe3+, and SO42− near the ground surface is found to be approximately 2–3 times higher in the case of variable flow. ... Opencast mining directly …

Acid mine drainage (AMD) is a major anthropogenic source of heavy metal discharge worldwide. However, little research has been carried out on the development of AMD in abandoned pyrite mines and the heavy metal contamination of mine surface water. The aim of this study was to investigate and assess heavy metal pollution in three …

1. Introduction. Acid mine drainage (AMD), primarily generated through natural oxidation, rainwater leaching, and oxidizing microbial action on metal sulfide minerals (mainly pyrite) in waste rocks and tailings, is the main source of heavy metal pollution in mining areas and their surrounding environments (Ighalo, 2022).A report …

Since 1970, coal production has been dominated by surface mining operations. In addition to exposing acid-generating FeS 2 to oxygen, surface mining also mechanically fragments large volumes of …

The Yunfu pyrite mine is located in northwestern Yunfu (22°57́–22°59́N, 112°0́-112°1́E), Guangdong Province, China. It is one of China's rare giant pyrite megadeposits, ... The surface water samples obtained from the Datai reservoir were of the Ca-SO 4 type, with the pH ranging from 2.89 to 3.25 and an average TDS concentration …

The mechanism of the initial steps of pyrite (100) surface oxidation was investigated in detail by means of density functional theory/plane-wave calculations. Pyrite oxidation is related to many environmental and …

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. ... Underground mining Surface (open pit) mining Placer mining The location and shape of the deposit, strength of the rock ...

Pyrite oxidation begins within minutes of exposure to the atmosphere, commencing with the oxidation of S 2− species. Schaufuß et al. [48] studied the …

The prevention of acid generation from sulfidic mine wastes is a problem that challenges the global scientific community for decades. A promising strategy is related to the formation of coating layer around sulfides for inhibiting surface oxidation. In the current research, the conditions favoring the formation of an efficient silicate-based coating …

For the synthetic mine waste (peak acidity ≈2000 mg·CaCO 3 ·L −1), the initial application of lime-saturated water alone (watering/flushing with Milli-Q water, thereafter) resulted in the maintenance of circum-neutral pH …

Pyrite depression in the flotation of copper ores is difficult due to the activation of Cu2+ ions on pyrite surface. In this study, the radical chain reaction involving the redox cycling of Cu(I/II) induced by sodium metabisulphite (MBS) was exploited to selectively depress the flotation of copper-activated pyrite at pH 8.0. Electrochemical …

Section snippets Methods and materials. Pyrite from the same source as Jerz and Rimstidt, 2004, Williamson and Rimstidt, 1994 was prepared in the manner described in Jerz and Rimstidt (2004) to recover the 250–420 μm size fraction with an estimated specific surface area of 1.13 × 10 −2 m 2 /g (Foust et al., 1980). The grains were sonicated in a …

H 2 O 2 oxidizes a small part of pyrite producing ferric iron (Fe 3+) anions. These cations subsequently react with the PO 4 3− anions to produce FePO 4 that precipitates on the pyrite surface producing a passive coating. This iron phosphate coating can protect the grains of pyrite from oxidation.

The new measurements reveal, among other things, that on pyrite's surface, a property called an energy bandgap — essential for making solar cells or semiconductor devices — has a value less than …

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 …

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 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.

In the case of drusy pyrite, the result is a surface that shimmers and sparkles with the reflective qualities of countless small pyrite crystals. ... One fascinating aspect of the pyrite found at the Eagle Mine is its striking brassy-yellow color and well-formed cubic or pyritohedral crystals. Some specimens may exhibit intricate intergrowths ...

Trace element contamination caused by mining is a serious environmental problem. The potential effects of exploiting the Yunfu pyrite mine (southern China) on soil were investigated by determining trace elements in 56 surface soil samples from the vicinity of the Yunfu pyrite mine. The samples were acid dissolved and measured by an …