Application of Laser Induced Luminescence in Ecology

1993 ◽  
Vol 27 (7-8) ◽  
pp. 547-556 ◽  
Author(s):  
M. Gaft
Keyword(s):  
New Technology ◽  
Ore Deposits ◽  
Ecological Effects ◽  
Low Grade ◽  
Ecological Damage

Exhaustion of rich ore deposits is making it necessary to bring low-grade ores into production, resulting in a sharply increased volume of excavated rock. Huge quantities of waste fill vast areas of the Earth's surface, with severe ecological effects. But the ecological damage could be reduced by extracting additional products from the tailings. Laseroluminescent sorting is a new technology by which this may be achieved. The most promising subjects are about 50 minerals including diamonds, native Au and Ag, ores of V, Pb, Zn, Sn, Li, Be, W, Mo, Zr, Sr, halite, apatite, phosphorite, fluorite, calcite, barite, anhydrite.

scholarly journals Impact of Sodium Hexametaphosphate on the Flotation of Ultrafine Magnesite from Dolomite-Rich Desliming Tailings

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 499
Author(s):  
Duong Huu Hoang ◽  
Doreen Ebert ◽  
Robert Möckel ◽  
Martin Rudolph
Keyword(s):  
Ultrafine Particles ◽  
Raw Materials ◽  
Low Cost ◽  
Froth Flotation ◽  
Open Circuit ◽  
Ore Deposits ◽  
Sodium Hexametaphosphate ◽  
Low Grade ◽  
Low Contrast ◽  
The Impact

The depletion of ore deposits, the increasing demand for raw materials, the need to process low-grade, complex and finely disseminated ores, and the reprocessing of tailings are challenges especially for froth flotation separation technologies. Even though they are capable of handling relatively fine grain sizes, the flotation separation of very fine and ultrafine particles faces many problems still. Further, the flotation of low-contrast semi-soluble salt-type minerals with very similar surface properties, many complex interactions between minerals, reagents and dissolved species often result in poor selectivity. This study investigates the flotation beneficiation of ultrafine magnesite rich in dolomite from desliming, currently reported to the tailings. The paper especially focuses on the impact of the depressant sodium hexametaphosphate (SHMP) on the following: (i) the froth properties using dynamic froth analysis (DFA), (ii) the separation between magnesite and dolomite/calcite, and (iii) its effect on the entrainment. As a depressant/dispersant, SHMP has a beneficial impact on the flotation separation between magnesite and dolomite. However, there is a trade-off between grade and recovery, and as well as the dewatering process which needs to be considered. When the SHMP increases from 200 g/t to 700 g/t, the magnesite grade increases from 67% to 77%, while recovery decreases massively, from 80% to 40%. The open circuit with four cleaning stages obtained a concentrate assaying 77.5% magnesite at a recovery of 45.5%. The dolomite content in the concentrate is about 20%, where 80% of dolomite was removed and importantly 98% of the quartz was removed, with only 0.3% of the quartz in the final concentrate. Furthermore, the application of 1-hydroxyethylene-1,1-diphosphonic acid (HEDP) as a more environmentally friendly and low-cost alternative to SHMP is presented and discussed. Using only 350 g/t of HEDP can achieve a similar grade (76.3%), like 700 g/t of SHMP (76.9%), while obtaining a 17% higher magnesite recovery as compared to 700 g/t of SHMP. Interestingly, the proportion of hydrophilic quartz minerals ending up in the concentrate is lower for HEDP, with only 1.9% quartz at a recovery of 21.5% compared to the 2.7% of quartz at a recovery of 24.9% when using SHMP. The paper contributes in general to understanding the complexity of the depressant responses in froth flotation.

Iberia and The Western Mediterranean

2014 ◽  
Author(s):  
William O'Brien
Keyword(s):  
New Technology ◽  
Western Mediterranean ◽  
Ore Deposits ◽  
Northern Spain ◽  
Metal Mining ◽  
Copper Ore ◽  
Copper Deposits ◽  
History Of ◽  
Copper Metallurgy ◽  
The 1960S

The Iberian Peninsula is one the most mineralized parts of Europe, with a long history of metal mining from prehistoric and Roman to modern times. The earliest evidence for copper metallurgy dates to the fifth millennium BC; however, distinctive Chalcolithic metalworking traditions did not emerge in most regions until 3000 BC onwards. There are widespread occurrences of copper mineralization in Spain and Portugal, including many areas with deposits of lead, tin, silver, and gold. Copper deposits occur in the Galician and Cantabrian mountain ranges of northern Spain, extending east to the Pyrenees. They are also numerous in central Spain, in the provinces of Madrid, Avila, Salamanca, and Segovia in the Central Range, and also in the Toledo and Betic mountains of Cordoba. Farther south, there are major copper deposits in the so-called Pyrite Belt, extending from Seville to Huelva into southern Portugal, and also in the Penibetic range from Cartagena to Malaga crossing the sierras of Almeria (Rovira 2002: fig. 3c; see Delibes de Castro and Montero Ruiz 1999 for regional surveys of copper deposits and indications of early mining; also Gómez Ramos 1999; Hunt Ortiz 2003). The widespread availability of ore deposits was a significant factor in the establishment of copper metallurgy in Iberia. How early is contentious, as is the means by which the new technology first developed in different parts of the peninsula. The older explanation of metal-seeking colonists from the east Mediterranean introducing this technology to southern Spain was replaced in the 1960s by a model that emphasized autonomous development (Renfrew 1967, 1973; Montero Ruiz 1994). This was based on the apparent antiquity of copper mining and metallurgy in Iberia and the distinctive technological processes that developed there relative to other parts of Europe. The earliest indication of copper metallurgy in Iberia may come from the settlement of Cerro Virtud in Almeria, south-west Spain. A single sherd from a metallurgical crucible used to reduce oxidized copper ore was discovered in a layer dated to the early fifth millennium BC (Montero Ruiz and Ruíz Taboada 1996; Ruíz Taboada and Montero Ruiz 1999).

scholarly journals Hydrogels Containing the Ferri/Ferrocyanide Redox Couple and Ionic Liquids for Thermocells

2019 ◽  
Vol 72 (2) ◽  
pp. 112 ◽  
Author(s):  
Matthew Russo ◽  
Holly Warren ◽  
Geoffrey M. Spinks ◽  
Douglas R. MacFarlane ◽  
Jennifer M. Pringle
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquids ◽  
Solid State ◽  
Waste Heat ◽  
New Technology ◽  
Redox Couple ◽  
Low Grade ◽  
Aqueous Electrolytes ◽  
Hydrogel Network ◽  
Water Based

Thermoelectrochemical cells are a promising new technology for harvesting low-grade waste heat. The operation of these cells relies on a redox couple within an electrolyte, which is most commonly water-based, and improvement of these materials is a key aspect of the advancement of this technology. Here, we report the gelation of aqueous electrolytes containing the K3Fe(CN)6/K4Fe(CN)6 redox couple using a range of different polymers, including polyvinyl alcohol (PVA), sodium carboxymethyl cellulose (Cmc), polyacrylamide (PAAm), and two commercial polyurethane-based polymers: HydroMed D640 and HydroSlip C. These polymers produce quasi-solid-state electrolytes with sufficient mechanical properties to prevent leakage, and allow improved device flexibility and safety. Furthermore, the incorporation of various ionic liquids within the optimized hydrogel network is investigated as a route to enhance the electrochemical and mechanical properties and thermal energy harvesting performance of the hydrogels.

Isolation, Identification and Screening of Manganese Solubilizing Fungi From Low-Grade Manganese Ore Deposits

2016 ◽  
Vol 34 (4) ◽  
pp. 309-316 ◽  
Author(s):  
S. Mohanty ◽  
S. Ghosh ◽  
S. Nayak ◽  
A. P. Das
Keyword(s):  
Ore Deposits ◽  
Low Grade ◽  
Manganese Ore

Chlorite and Epidote Mineral Chemistry in Porphyry Ore Systems: A Case Study of the Northparkes District, New South Wales, Australia

2020 ◽  
Vol 115 (4) ◽  
pp. 701-727 ◽  
Author(s):  
Adam Pacey ◽  
Jamie J. Wilkinson ◽  
David R. Cooke
Keyword(s):  
New South ◽  
New South Wales ◽  
Mineral Chemistry ◽  
Ore Deposits ◽  
Low Grade ◽  
South Wales ◽  
Spatial Trends ◽  
Propylitic Alteration ◽  
Mineral Partitioning

Abstract Propylitic alteration, characterized by the occurrence of chlorite and epidote, is typically the most extensive and peripheral alteration facies developed around porphyry ore deposits. However, exploration within this alteration domain is particularly challenging, commonly owing to weak or nonexistent whole-rock geochemical gradients and the fact that similar assemblages can be developed in other geologic settings, particularly during low-grade metamorphism. We document and interpret systematic spatial trends in the chemistry of chlorite and epidote from propylitic alteration around the E48 and E26 porphyry Cu-Au deposits of the Northparkes district, New South Wales, Australia. These trends vary as a function of both distance from hydrothermal centers and alteration paragenesis. The spatial trends identified in porphyry-related chlorite and epidote at Northparkes include (1) a deposit-proximal increase in Ti, As, Sb, and V in epidote and Ti in chlorite, (2) a deposit-distal increase in Co and Li in chlorite and Ba in epidote, and (3) a pronounced halo around deposits in which Mn and Zn in chlorite, as well as Mn, Zn, Pb, and Mg in epidote, are elevated. Chlorite Al/Si ratios and epidote Al/Fe ratios may show behavior similar to that of Mn-Zn or may simply decrease outward, and V and Ni concentrations in chlorite are lowest in the peak Mn-Zn zone. In comparison to porphyry-related samples, chlorite from the regional metamorphic assemblage in the district contains far higher concentrations of Li, Ca, Ba, Pb, and Cu but much less Ti. Similarly, metamorphic epidote contains higher concentrations of Sr, Pb, As, and Sb but less Bi and Ti. These chlorite and epidote compositional trends are the net result of fluid-mineral partitioning under variable physicochemical conditions within a porphyry magmatic-hydrothermal system. They are most easily explained by the contribution of spent magmatic-derived ore fluid(s) into the propylitic domain. It is envisaged that such fluids experience progressive cooling and reduction in fs2 during outward infiltration into surrounding country rocks, with their pH controlled by the extent of rock-buffering experienced along the fluid pathway.

Constraints on temperature–pressure conditions and fluid composition during metamorphism of the Sullivan orebody, Kimberley, British Columbia, from silicate–carbonate equilibria

1995 ◽  
Vol 32 (11) ◽  
pp. 1937-1949 ◽  
Author(s):  
Glen R. De Paoli ◽  
David R.M. Pattison
Keyword(s):  
British Columbia ◽  
Ore Deposits ◽  
Garnet Growth ◽  
Fluid Composition ◽  
Exchange Equilibrium ◽  
Low Grade ◽  
Metamorphic Temperature ◽  
Lower Temperature ◽  
Silicate Carbonate ◽  
Peak Metamorphic Temperature

The Sullivan mine, in southeastern British Columbia, is one of the world's largest sediment-hosted, massive sulphide deposits. It has undergone at least one period of metamorphism since it was deposited in mid-Proterozoic times. Mineral textures within the deposit are predominantly of metamorphic origin. A well-constrained estimate of metamorphic conditions is required to understand how the original, depositional character of the orebody has been modified by metamorphism. Metamorphic conditions were estimated using multiequilibrium thermobarometric techniques involving silicate–carbonate–fluid equilibria. Peak metamorphic temperature constrained by calibration of the garnet–biotite Fe–Mg exchange equilibrium is 450 ± 50 °C. Lower temperature estimates from some samples are interpreted to record the temperature of cessation of garnet growth prior to the attainment of peak metamorphic temperature. Peak metamorphic pressure as determined from equilibria applicable to the assemblage garnet–biotite–muscovite–chlorite–calcite–quartz–fluid is 380 ± 100 MPa. The fluid composition accompanying this pressure estimate is [Formula: see text], [Formula: see text]. This estimate is particular to one sample and may not be representative for the deposit as a whole. Metamorphic fluids at the estimated P–T conditions would not have contained significant concentrations of C–O–H–S species other than H2O and CO2. Textural evidence and temperature–pressure results from a titanite-bearing metamorphosed mafic intrusion in the deposit suggest published titanite ages near 1330 Ma in the area of the mine represent the age of the peak metamorphic event. The results of this study carry tectonic implications for the Sullivan area, and may have application to other metamorphosed ore deposits and low-grade metamorphic settings.

scholarly journals New technology for low-grade hardwood utilization: System 6

1982 ◽  
Author(s):  
Hugh W. Reynolds ◽  
Charles J. Gatchell
Keyword(s):  
New Technology ◽  
Low Grade

The Lavrion Pb-Zn-Ag–Rich Vein and Breccia Detachment-Related Deposits (Greece): Involvement of Evaporated Seawater and Meteoric Fluids During Postorogenic Exhumation

2019 ◽  
Vol 114 (7) ◽  
pp. 1415-1442 ◽  
Author(s):  
Christophe Scheffer ◽  
Alexandre Tarantola ◽  
Olivier Vanderhaeghe ◽  
Panagiotis Voudouris ◽  
Paul G. Spry ◽  
...  
Keyword(s):  
High Temperature ◽  
Fluid Inclusions ◽  
Meteoric Water ◽  
Ore Deposits ◽  
Metal Sulfides ◽  
Low Grade ◽  
High Grade ◽  
Base Metal Sulfides ◽  
Wide Range ◽  
Homogenization Temperatures

Abstract The formation of ore deposits in the Lavrion Pb-Zn-Ag district was associated with Miocene detachment that accommodated orogenic collapse and exhumation of high-grade nappes across the ductile-brittle transition. This district consists of (1) low-grade porphyry Mo style, (2) Cu-Fe skarn, (3) high-temperature carbonate replacement Pb-Zn-Ag, and (4) vein and breccia Pb-Zn-Ag mineralization. The vein and breccia mineralization locally contains high-grade silver in base metal sulfides that are cemented by fluorite and carbonate gangue. The rare earth element contents of these gangue minerals, chondrite-normalized patterns, and fluid inclusion studies suggest that they precipitated from a low-temperature hydrothermal fluid. Primary and pseudosecondary fluid inclusions in fluorite and calcite are characterized by a wide range of homogenization temperatures (92°–207°C) and salinities of up to 17.1 wt % NaCl equiv. Secondary fluid inclusions only represent <5 vol % of the total fluid trapped. Fluids extracted from inclusions in fluorite have values of δD = –82.1 to –47.7‰ (Vienna-standard mean ocean water [V-SMOW]) and δ18O = –10.4 to –5.1‰ (V-SMOW). These data and low ratios of Cl/Br measured by crush-leach analyses for fluids in fluorite (102–315) and calcite (162–188) are compatible with the ore fluid being the result of mixing of meteoric water with evaporated seawater. These data suggest that fluids leading to the deposition of late Pb-Zn-Ag–rich vein- and breccia-style mineralization in Lavrion were related to circulation of mixed evaporated seawater and meteoric fluids that was enhanced by brittle deformation. This contrasts with the fluids of magmatic origin related to the formation of low-grade porphyry Mo, Cu-Fe skarn, and high-temperature carbonate replacement deposits spatially related to the Plaka granodiorite.

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