Topic
Wolframite
About: Wolframite is a research topic. Over the lifetime, 760 publications have been published within this topic receiving 10004 citations.
Papers published on a yearly basis
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Papers
TL;DR: A qualitative model for the formation of mesothermal cassiterite(wolframite) deposits is derived from a review of geologic evidence and is then tested quantitatively with chemical mass transfer calculations based on published experimental and thermodynamic data.
Abstract: A qualitative model for the formation of granite-related mesothermal cassiterite(-wolframite) deposits is derived from a review of geologic evidence and is then tested quantitatively with chemical mass transfer calculations based on published experimental and thermodynamic data.Laboratory experiments and geologic, mineralogic, fluid inclusion, and stable isotope observations indicate that saline fluids of magmatic origin are involved in the formation of most tin ores that occur in veins, breccias, and replacement bodies of aluminosilicate or carbonate rocks. Transport of the ore fluid from a hot granitic source into a cooler depositional environment probably involves structural focusing and prevention of complete chemical reequilibration of the fluid with fresh quartzofeldspathic wall rocks. Under these conditions, a reduced acid fluid can transport high concentrations of Sn(II)-Cl complexes (hundreds of ppm metal) to a site of ore deposition at low temperature. Precipitation of cassiterite, Sn(IV)O 2 , requires oxidation and liberates acidity, which must be balanced by reduction and acid-consuming reactions involving other fluid and wall-rock components for cassiterite enrichment to proceed to economic concentrations. Several geologically likely deposition mechanisms have been tested, which differ in efficiency regarding the maximum tin ore grade that can be achieved in aluminosilicate host rocks. By contrast, wolframite can be precipitated by cooling of an Fe-W-bearing fluid without wall-rock reaction.Single-step acid neutralization of magmatic fluids by feldspar hydrolysis to sheet silicates (phyllic alteration) probably produces subeconomic greisen mineralization, because the maximum tin ore grade is severely constrained by the high acid content of the fluid. Progressive fluid-rock reaction and multistage ore reworking at an advancing alteration front, described by a one-dimensional finite-element reactor model assuming local equilibrium, may be a more efficient and geologically realistic process to form tin-rich greisens and breccia pipes. Loss of H 2 from a reduced tin-rich fluid by vapor separation, and simultaneous reaction with aluminosilicate rocks, is an alternative possibility for the formation of rich greisen-type deposits. Fluid mixing by injection of minor magmatic fluid into a cooler environment of convecting meteoric fluids could be a third, particularly efficient, tin-mineralizing mechanism in vein deposits without extensive wall-rock interaction. In this case and in the deposition of cassiterite by carbonate replacement, there are essentially no chemical limitations on tin ore grade, other than dilution of cassiterite by coprecipitating quartz and sulfides.
427 citations
TL;DR: In this article, the microwave dielectric properties of scheelite and wolframite AMoO4 compounds and their relations with structure have been examined using a network analyzer and X-ray powder diffraction.
Abstract: The microwave dielectric properties of scheelite (A = Ca, Sr, Ba) and wolframite (A = Mg, Mn, Zn) AMoO4 compounds and their relations with structure have been examined using a network analyzer and X-ray powder diffraction. The Mo ion polarizability has been also investigated from AMoO4 compounds using a least square refinement technique in conjunction with the Clausius–Mosotti equation. It was found that dielectric properties such as dielectric constant, temperature coefficient of resonant frequency, and quality factor were found to be correlated with the size of A-cations and the structure of compounds. The well sintered AMoO4 samples (>95% of theoretical density) exhibited dielectric constant of 7–11, quality factor of 37,000–90,000 GHz and temperature coefficient of resonant frequency of −57 to −87 ppm/°C, respectively. These investigations showed that AMoO4 ceramic could be selected as a possible candidate for microwave dielectric ceramics because of its low dielectric constant and high quality factor.
283 citations
TL;DR: In this article, four granite provinces have been delineated each with its own distinctive pattern of mineralization, including magnetite-cassiterite skarns ± base metal sulphides with antimony in Thailand.
Abstract: Four granite provinces have been delineated each with its own distinctive pattern of mineralization. 1. The Main Range Province. Endogenous greisen-bordered vein swarms of cassiterite and wolframite. 2. The Eastern Province. Magnetite–cassiterite skarns ± base metal sulphides with antimony in Thailand. 3. The Western (Peninsular Thailand–Burma) Province. Endogenous greisen-bordered vein swarms and pegmatites of cassiterite and wolframite. 4. The North Thailand Migmatitic Province. Endogenous vein and skarn replacement scheelite and fluorite deposits with some tin and local antimony. In all provinces, but particularly in the Main Range, granitoids designated as two-phase variants have been recognized where xenocrysts and xenoliths of coarse, primary texture granite are enclosed in, and corroded by an invasive, equigranular quartzo–feldspathic matrix. These rocks form an essential part of the granite sequence in all provinces and have probably resulted from the infiltration and disruption of the host granite by late stage magmatic fluids. Whole rock geochemistry from Peninsular Malaysia shows that the granites from the Main Range and Eastern Provinces comprise two contrasted suites which correspond approximately to the I and S-type categories advocated by Chappell & White (1974). In addition it is shown that individual plutons within batholiths in the two provinces have distinctive geochemical parameters. Variation diagrams of plutons having the intrusive sequence primary texture granite—two-phase granite—microgranite show linear trends with increasing SiO 2 , Na 2 O, Rb, W, Sn and U, and decreasing Sr, Ba, Th and all other major elements.
255 citations
TL;DR: In this article, the authors explore the mechanisms that lead to wolframite precipitation and evaluate whether they may exert a decisive control on tungsten global distribution, and demonstrate quantitatively that magmatic fluids at Panasqueira, Portugal, provide tungststen in solution, whereas the host rock contributes the iron required to precipitate wolframites.
Abstract: Tungsten mineralization is typically associated with reduced granitic magmas of crustal origin. While this type of magmatism is widespread, economic tungsten deposits are highly localized, with ∼90% produced from only three countries worldwide. Therefore, the occurrence of reduced magmatism, while necessary for tungsten enrichment, seems to be insufficient to form such rare deposits. Here we explore the mechanisms that lead to wolframite precipitation and evaluate whether they may exert a decisive control on tungsten global distribution. Tungsten differs from other rare metals enriched in magmatic-hydrothermal ore deposits because it is transported as an anionic species. Precipitation of the main tungstate minerals scheelite, CaWO 4 , and wolframite, (Fe, Mn)WO 4 , thus depends on the availability of calcium, iron, or manganese. We demonstrate quantitatively that magmatic fluids at Panasqueira, Portugal, provide tungsten in solution, whereas the host rock contributes the iron required to precipitate wolframite. The combination of special source conditions with specific reactive host rocks explains why major wolframite deposits are rare and confined to a few ore provinces globally.
192 citations
TL;DR: In this article, a review of various approaches to improving the beneficiation efficiency of tungsten ores are reviewed, including selective flotation of scheelite from other calcium containing minerals such as calcite and fluorite using more selective reagents.
135 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 17 |
| 2024 | 28 |
| 2023 | 59 |
| 2022 | 76 |
| 2021 | 37 |
| 2020 | 45 |