A Literature review on the Geology and Mineral Industry of Sierra Leone

September 24th, 2013  Posted by jmwarnsloh

Geologic Country Report with Emphasis on Diamonds, Gold, and Titanium (July 2011)
The Republic of Sierra Leone is located on the West Coast of Africa, between latitudes 7 and 10 north and longitudes 10.5 and 13 west.
The mining sector is a significant contributor to Sierra Leone’s economy; it accounted for about 90 % of export revenues, mainly from diamond exports, and 20 % of the gross domestic product (GDP). Sierra Leone was the world’s 10th ranked producer of diamond by volume in 2009 and the world’s third ranked producer of rutile.

Minerals of the pyrochlore group as niobium-ore

March 27th, 2012  Posted by jmwarnsloh

In comparison to other commodities, e.g. gold, niobium-ores are related to a small number of igneous rocks, in particular carbonatites and genetically-related silicate-carbonate rocks.
Within these rocks niobium is segregated principally in oxide minerals such as the pyrochlore-microlite solid solution series (Ca,Na)2(Nb,Ta)2O6(O,OH,F) and niobian perovskite (Ca,Na)(Ti,Nb)O3. At least four other Nb minerals can occur in sufficient quantities to dominate or affect the niobium content of a carbonatite. They include ferrocolumbite FeNb2O6, fersmite (Ca,REE,Na)(Nb,Ta,Ti)2(O,OH,F)6, niocalite Ca4NbSi2O10(O,F), and wöhlerite NaCa2(Zr,Nb)Si2O8(O,OH,F). Pyrochlore is the dominant niobium host and the only mineral

World-wide Niobium and Tantalum Availability

March 26th, 2012  Posted by jmwarnsloh

Niobium is a shiny, white, soft, and ductile metal with superconductive properties. Niobium products are used in a wide variety of applications. The largest end market for HSLA steel is for large diameter steel pipelines for the transmission of natural gas and oil. Price increases in oil and natural gas during the last years have created a new interest in exploration for, and