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We have a demand for the following product
Tantalite
We are buyers of tantalite, please send us your current offer
Our requirements are:
- Minimum Ta2O5 content to be 15 %
- Minimum Quantity 10 mt for low grade and 5 mt for high grade material
- Payment after delivery and inspection by A.H. Knight
TANTALUM
Tantalum ores are found primarily in Australia, Canada, Brazil, and
central Africa, with some additional quantities originating in
southeast Asia. The average yearly growth rate of about 8 to 12% in
tantalum demand since about 1995 has caused a significant increase in
exploration for this element. Tantalum minerals with over 70 different
chemical compositions have been identified. Those of greatest economic
importance are tantalite, microlite, and wodginite; however, it is
common practice to name any tantalum-containing mineral concentrate as
'tantalite' primarily because it will be processed for the tantalum
values and is sold on that basis. Tantalum mineral concentrates may
contain from two to more than five different tantalum-bearing minerals
from the same mining area. The sale of tantalum mineral concentrates is
based on a certified analysis for the tantalum oxide they contain, with
a range from 10 or 15 to over 60% depending on the mine source.
The single largest source of tantalum mineral concentrates is the
production by Sons of Gwalia Ltd. from its Greenbushes and Wodgina
mines in Western Australia. These two mines combined produce between 25
and 35% of the world's supply, with production in 2001 reported at
approximately 1.8 million pounds. Additional operating mines are the
Tanco Mine (Cabot) in Manitoba, Canada, the Kenticha Mine (Ethiopia
Minerals Development Authority) in Ethiopia, the Yichun Mine in China,
and the Pitinga Mine (Paranapanema) and Mibra Mine (Metallurg) in
Brazil. Additional quantities are available from Brazil through the
processing of small alluvial deposits by prospectors and in numerous
countries in Africa, such as Rwanda, Namibia, Uganda, DRC-Kinshasa,
Zaire, Gabon, Nigeria, South Africa, and Burundi. Mining investment in
Africa has been curtailed due to political instability and associated
risk.
The central African countries of Democratic Republic of the Congo
(DRC-Kinshasa) and Rwanda and their neighbours used to be the source of
significant tonnages. But civil war, plundering of national parks and
exporting of minerals, diamonds and other natural resources to provide
funding of militias has caused the Tantalum-Niobium International Study
Center to call on its members to take care to obtain their raw
materials from lawful sources. Members should refrain from purchasing
materials from regions where either human welfare or wildlife are
threatened.
The downsizing of the tin industry in southeast Asia and elsewhere
over the period of 1980 through about 1990 has led to the reduction of
tantalum oxide units available from tin slags, a by-product of the
smelting of cassiterite ore concentrates for tin production. Although
some tin slags are available from new tin production, the primary
source today is from the digging up of old dump areas containing 1.5 to
about 4.0% tantalum oxide. It should be noted that struverite
concentrates have been available from this general area containing
9-12% tantalum oxide.
Scrap recycling generated within the various segments of the
tantalum industry accounts for about 20 to 25% of the total input each
year.
Extraction/refining
The extraction and refining of tantalum, including the separation
from niobium in these various tantalum-containing mineral concentrates,
is generally accomplished by reacting the ores with a mixture of
hydrofluoric and sulfuric acids at elevated temperatures. This causes
the tantalum and niobium values to dissolve as complex fluorides, and
numerous impurities that were present also dissolve. Other elements
such as silicon, iron, manganese, titanium, zirconium, uranium,
thorium, rare earths, etc. are generally present. The filtration of the
digestion slurry, and further processing via solvent extraction using
methyl isobutyl ketone (MIBK) or liquid ion exchange using an amine
extractant in kerosene, will produce highly purified solutions of
tantalum and niobium. Generally, the tantalum values in solution are
converted into potassium tantalum fluoride (K2TaF7) or tantalum oxide
(Ta2O5). The niobium is recovered as niobium oxide (Nb2O5) via
neutralization of the niobium fluoride complex with ammonia, forming
the hydroxide, followed by calcination to the oxide.
The primary tantalum chemicals of industrial significance, in
addition to K2TaF7 and Ta2O5 are tantalum carbide (TaC), tantalum
chloride (TaCl5), and lithium tantalate (LiTaO3).
Tantalum metal powder is generally produced by the sodium reduction
of the potassium tantalum fluoride in a molten salt system at high
temperature. The metal can also be produced by the carbon or aluminum
reduction of the oxide or the hydrogen or alkaline earth reduction of
tantalum chloride. Capacitor grade powder is produced by the sodium
reduction of potassium tantalum fluoride. The choice of process is
based on the specific application and whether the resultant tantalum
will be further consolidated by processing into ingot, sheet, rod,
tubing, wire, and other fabricated articles.
Capacitor grade tantalum powder provides about 60% of the market use
of all tantalum shipments. Additional quantities are consumed by
tantalum wire for the anode lead as well as for heating elements,
shielding, and sintering tray assemblies in anode sintering furnaces.
The consolidation of metal powder for ingot and processing into
various metallurgical products begins with either vacuum arc melting or
electron beam melting of metal feedstocks, comprised of powder or high
purity scrap where the elements with boiling points greater than
tantalum are not present. Double and triple melt ingots achieve a very
high level of purification with regard to metallics and interstitials.
Ingots are used to produce the various metallurgical products named
earlier. Ingot stock is also used for the production of such alloys as
tantalum-10% tungsten. Ingot and pure scrap are used in the production
of land and air-based turbine alloys.
Applications for Tantalum
|
Tantalum Product |
Application |
Technical Attributes/Benefits |
|
Tantalum carbide |
Cutting tools |
Increased high temperature deformation, control of grain growth |
|
Tantalum oxide |
- Camera lenses |
- High index of refraction for lens compositions |
|
Tantalum powder |
Tantalum capacitors for electronic circuits in medical appliances such as hearing aids, pacemakers, airbag protection systems, ignition and motor control modules, GPS, ABS systems in automobiles, laptop computers, cellular phones, Playstation, video cameras, digital still cameras |
Low failure rates, operation over a wide temperature range from -55 to +125°C, can withstand severe vibrational forces, high reliability characteristics, small size per microfarad rating/electrical storage capability |
|
Tantalum fabricated sheets, plates, rods, wires |
- Sputtering targets |
- Applications of thin coatings of tantalum, tantalum oxide or nitride coatings to semi-conductors |
Please send your offers to:
E&C Trading Ltd., P.O. Box 249, CH-6343 Rotkreuz / Switzerland
Tel. +41 41 790 60 90
Fax +41 41 790 72 92 and (USA 530 280 88 77)
send an e-mail to E&C Trading Ltd.
Document last modified on: 19.02.2006
webmaster @ ectrading.com