Topic
Stibiconite
About: Stibiconite is a research topic. Over the lifetime, 21 publications have been published within this topic receiving 193 citations.
Papers
TL;DR: The Kharma antimony vein in the Cordillera Oriental, Bolivia, is representative of vein-type antimony deposits that have stibnite as the only mineral of economic interest and a low gold content.
Abstract: The Kharma antimony deposit in the Cordillera Oriental, Bolivia, is representative of vein-type antimony deposits that have stibnite as the only mineral of economic interest and a low gold content. In this deposit, recovery of gold is difficult because it is not known exactly where the gold is located within the ore shoots or the manner in which it is present in the main minerals of the deposit. Vein mineralization of this type is widespread, for example, in Spain, Germany, France, and Turkey. As with similar antimony deposits in Europe, this Bolivian Sb mineralization is bound to a fault zone that cuts dark, fine- grained clastic rocks of early Paleozoic age. Field evidence suggests that the mineralization is younger than Cretaceous. The country rocks have been subjected to regional dynamic metamorphism of greenschist facies, during which minute streaks of pyrite and other base metal sulfides formed parallel to the S planes of the siliceous pelites. Gold and antimony do not form discrete minerals in this wall-rock mineralization. Our studies of the fault-hosted mineralization reveal different genetic trends of gold concentration and depletion. During an early episode of vein formation, gold was added as "invisible gold" (up to 0.2 wt % Au) in arsenopyrite of substage Ia at temperatures somewhat higher than 400 degrees C, and as native gold (gold 1) containing little silver (up to 99.9 wt % Au) in substage Ib at temperatures somewhat higher than 300 degrees C. Arsenopyrite is considered the primary host for Au. It was converted by shear stress in the fault zone into As-bearing pyrite with a maximum of 268.8 ppm Au. Neither stibnite nor antimony sulfosalts, both of which are major stage II minerals in addition to quartz, is host to appreciable gold concentrations (max 0.8 ppm). Fluid inclusion studies on stage II quartz indicate a temperature of formation of 130 degrees to 234 degrees C. Stage III is characterized by an influx of Ag-bearing solutions at temperatures below 360 degrees C, which led to the conversion of primary gold (gold I) into argentiferous gold (gold II) and reaction of gold and stibnite to form antimony and aurostibite. Native gold was included by aurostibite during stage III and by Au-Sb oxides during stage IV. This inclusion of gold was accompanied by the precipitation of kaolinite, alunite, and schafarzikite (FeSb 2 O 4 ). The temperature of formation of this late-stage redeposition of the gold can be inferred only from present-day brines that emerge near the antimony vein at temperatures below 72 degrees C. Stage V reflects the adjustment of primary Sb mineralization to near-surface conditions by the formation of stibiconite and goethite...
43 citations
TL;DR: In this article, the authors examined many specimens of antimony ochre and found that the commonest mineral in these specimens proved to be stibiconite, but others were found, and to establish their identity it became necessary to study the secondary products as a group.
Abstract: URING an investigation of stibiconite and cervantite (Vitaliano and Mason, 1952) we examined many specimens of antimony ochre. The commonest mineral in these specimens proved to be stibiconite, but others were found, and to establish their identity it became necessary to study the secondary products as a group. The mineralogy of these oxygenated secondary antimony minerals presents unusual problems on account of their earthy and often inhomogeneous nature. Our experience indicates that without X-ray powder photographs it is difficult to establish the true identity of much of this material. The purpose of this paper is to present the results of our investigations and to provide more adequate descriptions of some little-known species. We would take this opportunity of expressing our appreciation to a number of persons who aided us. Professor C. Frondel of Harvard University, Dr. G. Switzer of the U.S. National Museum, Professor A. Pabst of the University of California, and Dr. H. Neumann of the Mineralogisk Museum in Oslo, made available material from the collections under their care. Dr. D. E. White of the U.S. Geological Survey provided us with a fine collection of secondary antimony minerals from Mexican deposits, which included the new mineral bystrSmite and material of the rare iron antimonate tripuhyite. Mr. Victor Barua obtained for us specimens of the Peruvian minerals coronguite and arequipite. ~umerous spectrographic analyses were made by Mr. R. K. Leininger of the Indiana Geological Survey. Several partial and complete chemical analyses were made by Mr. M. E. Coller. To all these persons our thanks are due. Antimony oxides.
32 citations
TL;DR: In this article, the authors investigated the natural attenuation of arsenic (As) and antimony (Sb) in highly contaminated soils at the abandoned Sb-deposit Poproc in eastern Slovakia.
Abstract: This contribution investigates the natural attenuation of arsenic (As) and antimony (Sb) in highly contaminated soils at the abandoned Sb-deposit Poproc in eastern Slovakia. The studied soils were identified as technosols with pH values of 3.5–7.0 and high metal and metalloid load: antimony, arsenic, lead, and zinc up to 5757, 2484, 683, and 407 mg/kg, respectively. These toxic elements occur in the soils mainly as constituents of secondary minerals, which are products of sulphide oxidation. Bulk correlation between Fe and As is weak (p > 0.05), but inspection of micro-X-ray fluorescence maps shows that the secondary iron oxides are always associated with elevated As. Electron microprobe (EMP) and micro-X-ray diffraction analyses showed significant chemical and mineralogical heterogeneity of the secondary minerals, with wide variations of their Fe/Sb ratio and occasionally elevated Ca and Pb (> 5 wt%). The most common secondary minerals are goethite (α-FeOOH) with concentrations of Sb up to 3.14 wt% and As (1.29 wt%) and tripuhyite (FeSbO4) with increased content of As (1.14 wt%). Sb-rich secondary phases were identified as valentinite/senarmontite (Sb2O3), cervantite (Sb2O4), and a pyrochlore-group mineral stibiconite. High Sb phases with increased concentrations of Ca (up to 6.48 wt%) or Pb (20.78 wt%) were identified as stibiconite (EMP). This study shows that the secondary mineralogy in naturally attenuated contaminated soils and in Sb-containing tailings is identical. Hence, such tailings achieve their final state with respect to the Sb minerals within decades and are unlikely to change further.
26 citations
TL;DR: Raman spectroscopy has been sued to study the antimony containing mineral roméite Ca( 2)Sb(2)O(6)(OH,F,O) from three different origins.
21 citations
TL;DR: In this paper, the synthesis of nanosized hydrated antimony oxide as an ion exchange material via sol-gel process using water as a reagent to control the pH and to obtain a pure and dense hydrated Antimony oxide.
Abstract: The study focused mainly on the synthesis of nanosized hydrated antimony oxide as an ion exchange material via sol-gel process using water as a reagent to control the pH and to obtain a pure and dense hydrated antimony oxide. The obtained antimony oxide was characterized using X-ray diffractometer, scanning electron microscope, TG-DTA, and fourier transform infrared spectroscopy. The result showed the formation of stibiconite with a cubic crystal structure in nanometric range (9.54 nm). FTIR study confirmed the formation of antimony oxide with characteristic bands at about 766 and 552 cm–1 attributed to Sb–O streatching modes of Sb–O–Sb and Sb–OH, respectively. The synthesized hydrated antimony oxide demonstrated monofunctional ion-exchange characteristic and reasonably good chemical stability in acidic and basic media. The synthesized ion exchanger was then used for the removal of lanthanum(III) and samarium(III) from aqueous solutions. As can be seen from distribution studies the distribution coefficient K
d increased with increasing the reaction temperatures of the solution. Adsorption experiments were carried out using both batch and column systems. The Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) equilibrium models were used and a value q
max was 41.10 and 48.42 mg g–1 for La(III) and Sm(III), respectively. Thermodynamic parameters, ΔH°, ΔG°, and ΔS° were calculated and indicated an endothermic and spontaneous process.
20 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2019 | 2 |
| 2015 | 1 |
| 2013 | 1 |
| 2011 | 1 |
| 2010 | 4 |
| 2006 | 1 |