· Request PDF | Emerging role of organic acids in leaching of valuable metals from refinery-spent Moreover, concentrated metals must be refined (Ding et al. 2019; Pathak et al. 2020 ; Wiecka et
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· 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
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· Increasing population levels, growing economies, rapid urbanization and changes in consumption patterns have increased the demand for raw materials such as base and precious metals, leading to growing concerns regarding their availability and the global efficiency of the mine supply chain. Mine tailings, consisting of process effluents
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2011. TLDR. It is found that the composition of the ore particle plays a crucial role in the ability of each acid to solubilize potassium and phosphorous, and iron ore particles that contained different combinations of the potassium bearing mineral phase’s muscovite, illite, K-feldspar and biotite were solubilant differently by the acids tested.
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The concentrated solution obtained from membrane distillation underwent sulfuric acid extraction using a popypropylene hollow fiber membrane module provided by Liqui-CellTM. The module, consisting of approximately 10,000 fibers with an effective length of 15 cm, operated at room temperature (25 ± 2 °C).
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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
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· However, if that acid is replaced by concentrated hydrochloric (12 mol l −1) or phosphoric (14.7 mol l −1) acids, the results are significantly dependent on the concentration of dissolved oxygen, in addition to the already reported drop in
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· The paper analyzes the process of incongruent dissolution of silicates taking place in close proximity to a talc mine. pseudo-total PTE content using a mix of concentrated acids (38% HCl + 65%
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The mechanisms are: (1) convection, which takes place because of the exerted pressure difference across the membrane. (2) diffusion, which takes place as a result of the concentration gradient across the membrane, and (3) charge effects, which are due to potential gradient or which take place as a result.
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· Oxidation of sulphide mining waste can generate acid mine drainage (AMD) that has the potential to seriously affect the ecosystems. Acid mine drainage is characterised by a high acidity, high concentrations of sulphates and metals. To reduce the environmental impacts due to AMD, neutralisation using limestone drains is an option
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Acid mine drainage is often recognised by the presence of bright orange water and stained rocks. As ferric hydroxide [Fe (OH) 3] precipitates out of the water, it leaves the water an orange colour. As AMD is neutralised, the precipitate appears to be growing. Increased pH causes the iron to oxidise and precipitate out.
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· Gold is a highly required material for a wide range of personal and industrial applications. The high demand for gold, together with the shortage of natural resources and high pollution potential of wastes generated during mining and ore processing activities led to search for alternative sources of gold. A possible source is
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To prepare a 0.5 M (1 N) sulfuric acid solution from concentrated sulfuric acid, pipette 28 mL of concentrated sulfuric acid into 500 mL of deionized water in a 1 L volumetric flask. Cool to room temperature, then bring to volume with Type I deionized water. Transfer
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· If a proper tailings management method is not chosen to dispose of such hazardous material, environmental problems such as acid mine drainage (AMD) will be faced due to the oxidation of
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· The roles of metals were further studied using the correlation between the weight of the phenolic monomers produced per surface Pd site and acid site quantity (Fig. 4 (f)). This correlation was positive, which indicated that acid sites facilitate lignin depolymerization.
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Q. What would you observe in the following cases? (i) Sulphur trioxide is dissolved in water on a large scale. (ii) Concentrated sulphuric acid is added to equal volumes of cold water. (iii) 100 ml of 98% sulphuric acid is kept open. (iv) Hot concentrated sulphuric acid is added to sodium chloride crystals. (v) Dilute sulphuric acid is added to
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· Concentrated acid is a solution with a high amount of solute (acid) dissolved in a solvent, whereas a strong acid is one that completely ionizes in solution, producing a high concentration of hydrogen ions (H⁺). A concentrated acid can be made dilute if we add more water to it, but a strong acid may remain strong even if we dilute it.
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· To test the effects of secondary mineral formation on cement neutralisation of acid mine drainage (AMD), cement samples were leached with AMD and dilute sulfuric acid of approximately equal acidity. In both cases the neutralising efficiency of the cements, due to dissolution of portlandite as well as the hydrated calcium silicate and aluminate
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· Lignin isolated by two-step concentrated acid hydrolysis of empty fruit bunch (EFB) was effectively depolymerized into a high-quality bio-oil using formic acid (FA) as an in-situ hydrogen source and Ru/C as a catalyst in supercritical ethanol. A bio-oil yield of 66.3 wt% with an average molecular weight of 822 g/mol and an aromatic monomer
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· For example, dissolved Hg can become strongly associated with DOM via −S and −O functional groups on the organic matter, 13,16,17,59,60 and organic acids can favor the transport of HgS
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· Sulphidic mine tailings are among the largest mining wastes on Earth and are prone to produce acid mine drainage (AMD). The formation of AMD is a sequence of complex biogeochemical and mineral dissolution processes. It can be classified in three main steps occurring from the operational phase of a tailings impoundment until the final
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· Molar fractions of reaction products as a function of time during acid-catalysed hydrolysis of the fully N-acetylated chitin tetramer (A4) in concentrated hydrochloric acid at 40 C. Theoretical values for the molar fractions are indicated by continuous lines, with k 1 = 2.5 · 10 −5 s −1 and k 2 = 1.0 · 10 −5 s −1 .
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Conclusion. Calcination is an essential tool in the conversion of spodumene concentrates to lithium compounds, with two key roles in the process. Through calcination, both decrepitation and acid roasting can be achieved in the effort to produce lithium carbonate and lithium hydroxide for use in lithium-ion batteries or other applications.
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The Role of Microorganisms in Acid Mine Drainage: A Preliminary Report. The Role of Microorganisms in Acid Mine Drainage: A Preliminary Report. Science. 1947 Sep 19;106 (2751):253-6. doi: 10.1126/science.106.2751.253.
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· Zundel et al. published IR spectra of concentrated phosphoric acid solutions (with less than one water molecule/acid molecule) showing three strong, overlapping absorptions in the 3000–2500 cm −1 region (strongly absorbing ν OH), 2400–2200 cm −1 δ OH −1
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The mining industry has an obligation to prevent the release of toxic chemicals into the environment, ensuring that humans, birds, animals, and aquatic life are not endangered by the storage and
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· Acid mine drainage (AMD) is initiated by the hydro-geochemical weathering of sulfide bearing rocks Aluminium tolerance in plants and the complexing role of organic acids Trends Plant Sci. (2001), 10.1016/S1360-1385(01)01961-6 Google
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For example, the world’s largest copper mine, Escondida in Chile, appears to have reached a peak and its production in 2025 is expected to be at least 5% lower than today. On the back of optimism for copper’s role in the energy transition, investment has been
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· Understanding the Role of Concentrated Phosphoric Acid Solutions as High -Temperature Silicon Nitride Etchants March 2021 ECS Journal of Solid State Science and Technology DOI:10.1149/2162-8777
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MILLER A, WILDEMAN T, FIGUEROA L. Zinc and nickel removal in limestone based treatment of acid mine drainage:the relative role of adsorption and co-precipitation[J]. Applied Geochemistry, 2013, 37:57-63.
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Trituradora de piedra vendida por proveedores certificados, como trituradoras de mandíbula/cono/impacto/móvil, etc.
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