Results 171 to 180 of about 1,478 (213)

On the hydrothermal synthesis of wolframite

Chemical Geology, 1985
Abstract Wolframite was synthesized hydrothermally at 1 kbar between temperatures of 200° and 400°C. The pH-values and periods of cooling were varied. The crystallographic constitution and the chemical composition were investigated by electron probe microanalysis.
Josef-Christian Buhl, Alexander Willgallis   +1 more
openaire   +1 more source

Mössbauer study of natural wolframites

Hyperfine Interactions, 1991
Natural Wolframite, (FexMn1−x)WO4 withx=0.95 to 0.41, obtained from seven different sites of two quartz-wolframites deposits of Degana and Sirohi in Rajasthan. India, have been studied by Mossbauer spectroscopy down to 20 K. X-ray diffraction studies with a monochromatic Cu radiation (λKa-1.5405 A), were carried out to determine the value ofx.
J. S. Saini, V. K. Garg, K. Chandra
openaire   +2 more sources

Analytical Fingerprint of Wolframite Ore Concentrates

Journal of Forensic Sciences, 2017
AbstractOngoing violent conflicts in Central Africa are fueled by illegal mining and trading of tantalum, tin, and tungsten ores. The credibility of document‐based traceability systems can be improved by an analytical fingerprint applied as an independent method to confirm or doubt the documented origin of ore minerals.
Hans-Eike, Gäbler, Wilhelm, Schink, Simon, Goldmann, Andreas, Bahr, Timo, Gawronski   +4 more
openaire   +2 more sources

High-Pressure Synthesis of Molybdates with the Wolframite Structure

Science, 1963
A series of small cation molybdates, MgMoO 4 , MnMoO 4 , FeMoO 4 , CoMoO 4 , NiMoO 4 , and ZnMoO 4 with the wolframite structure characteristic of the corresponding tungstates have been synthesized
A P, Young, C M, Schwartz
openaire   +2 more sources

Vibrational spectra of compounds with the wolframite structure

Spectrochimica Acta Part A: Molecular Spectroscopy, 1994
The vibrational (IR absorption and Raman) spectra of the tungstates of the composition ZnWO4, CdWO4, β-LiYb(WO4)2, LiFe(WO4)2 and LiIn(WO4)2 crystallizing in the wolframite structural type, including those of lithium isotope 6Li7Li, iron isotope 54Fe58Fe and zinc isotope 64Zn68Zn substituted samples have been studied. Assignments and analysis of the
V.V. Fomichev, O.I. Kondratov
openaire   +1 more source

M�ssbauer study of natural wolframites

Physics and Chemistry of Minerals, 1982
The first Mossbauer results obtained with powdered samples of natural wolframites Fex Mn1−x WO4 from some famous Portuguese and Peruvian mines are reported here. The Mossbauer experiments have been carried out at 300, 77 and 4.2 K with four natural and one synthetic powdered samples of different compositions.
R. Guillen, J. R. Regnard, J. Amoss�
openaire   +1 more source

Mechanical Activation of Processing of Egyptian Wolframite

2015
The present work is related with mechanical activation of processing of Egyptian wolframite by simultaneous ball-milling and pressure alkaline leaching, to improve the recovery of tungsten from wolframite. The results show a total recovery of tungsten from wolframite (97.8 – 98.7%) by simultaneous ball-milling and alkaline leaching at temperature 175 ...
Aly M. Abdel-Rehim, Mohamed Y. Bakr
openaire   +1 more source

Effect of structural changes on energy content and reactive capacity of wolframite after mechanical activation of standard wolframite concentrate

Journal of Mining Science, 2017
The article shows predictability of change in energy content and reactive capacity of standard wolframite concentrate after mechanical activation based on the data of X-ray structure analysis during later-on low-temperature (under 100 °С) alkali leaching.
E. V. Bogatyreva, A. G. Ermilov
openaire   +1 more source

THE MAGNETIC PROPERTIES OF WOLFRAMITE GROUP MINERALS

International Geology Review, 1960
The study of magnetic properties of members of the wolframite group indicates that they are paramagnetic minerals. Anisotropy of magnetic susceptibility is characterized by the presence of three principal directions. Two of these directions coincide with the crystallographic axis.
openaire   +1 more source

Wolframite (wf)

2023
openaire   +1 more source