Lithium minerals are being used increasingly as a batch
constituent. The following article reviews recent
developments
within
the lithium minerals industry and outlines the applications in which-the
raw materials are used.
The estimated consumption of lithium minerals in the western
world in 1996 as raw materials to the glass, ceramic and metallurgical industries totalled 151,000 tonnes or 19,500
tonnes lithium carbonate equivalent (LCE). This does not include lithium
minerals which are used to produce lithium carbonate.
Overall tonnage demand for lithium minerals increased by
8.6% to
12,000 tonnes in 1996 against the previous year. While this growth is in
itself significant and is almost double the average GNP of the major
western nations, it is interesting to note that during the period from
1992-1996, overall tonnage demand has increased by 77% from 85,500 to
151,000 tonnes.
There are four major lithium minerals producers.
* Gwalia Consolidated in Western Australia is the largest producer
of spodumene, supplying high grade spodumene concentrate, fine spodumene
concentrate, glass grade spodumene and chemical grade spodumene.
* Tantalum Mining Corporation (Tanco) in Manitoba, Canada produces
high grade spodumene concentrate, fine spodumene, low grade spodumene
and montebrasite.
* Bikita Minerals in Zimbabwe is the largest producer of petalite,
supplying standard grade, low alkali and container glass petalite to the
market. The company also produces spodumene concentrate.
* Sociedad Mineria De Pegmatites, Portugal produces lepidolite.
However this company sells its lithium mineral in a unprocessed form.
A full breakdown of the estimated world sales and production
capacities are shown in table I. Typical [Li.sub.2]O concentrations of
the lithium products available are outlines in table II.
Table I.
Production capacity Sales (tonnes)
(tonnes)
Gwalia Australia 150,000 (63%) 75,000 (49%)
Brazil/Namibia(*) 2000 (1%) 2000 (1%)
Bikita Zimbabwe 42,000 (18%) 34,000 (22%)
Pegmatites Portugal 25,000 (10%) 20,000 (13%)
Tanco Canada 21,000 (9%) 22,000 (14%)
Table II.
Spodumence
Concentrate Low grade
Gwalia Australia 7.6% [Li.sub.2] O
Consolidated 0.07% [Fe.sub.2] [O.sub.3] 0.08% [Fe.sub.2]
[0.sub.3]
Tantalum 7.25% [Li.sub.2] O 6.80% [Li.sub.2] O
Mining Co 0.05% [Fe.sub.2] [.sub.3]
Bikita 7.30% [Li.sub.2] O
Minerals 0.04% [Fe.sub.2] [O.sub.3]
Namibia
Lithium
Mines
Sociedada
Miniera De Unprocessed lepidolite
Pegmatite
Spodumence Petalite
Fine Standard
Gwalia Australia 5.0% [Li.sub.2] 0 7.5% [Li.sub.2] O
Consolidated 0.15% [Fe.sub.2] [O.sub.3]
Tantalum 7.1% [Li.sub.2] O
Mining Co
Bikita 4.2% [Li.sub.2] 0
Minerals 0.04% [Fe.sub.2]
[0.sub.3]
Namibia 4.1% [Li.sub.2] 0
Lithium 0.03% [Fe.sub.2]
[O.sub.3]
Mines
Sociedada
Miniera De
Pegmatite
Container Low
grade alkali
Gwalia Australia
Consolidated
Tantalum
Mining Co 2.1% [Li.sub.2] 0 4.5% [Li.sub.2] 0
Bikita 0.04% [Fe.sub.2] [O.sub.3] 0.04% [Fe.sub.2]
[O.sub.3]
Minerals
Namibia
Lithium
Mines
Sociedada
Miniera De
Pegmatite
The major developments within the lithium minerals industry, by
major producers during the year have been,-firstly, the certification of
Bikita to ISO 9002 quality standards. The company now joins Gwalia as a
holder of the quality certificate.
Secondly, the installation of an upgraded concentrator by Bikita to
meet the increasing demand for lithium mineral concentrate.
Applications
Traditional
applications are in the production of low thermal
expansion glass ceramics, low thermal expansion fully vitrified
ceramics, frits and glazes, monochromatic and colour TV components, bulk
glass packaging, high quality tableware and perfume containers.
Glass ceramics
In low thermal expansion ceramics and glass ceramics, the addition
of lithium and promotion of beta spodumene is the basis for production
of glass ware with extreme heat shock resistance. Products exploiting
this physical property include oven-to-tableware glass ceramics and
ceramic oventops. This market sector, in which lithium is an essential
part of the composition, is growing in accordance with GNP.
Vitrified ceramics
Fully and semi-vitrified ceramic manufacturers continue to use
lithium to permit lower firing temperatures and allow a faster cooling
rate and a quicker kiln turnaround.
In addition to this market sector, lithium is being used in
unglazed ceramic wall and floor tiles. It has been found that lithium
increases the activity in the glassy phase during the consolidation
process. The increased reactivity means that firing times and
temperatures are reduced.
Secondly, the linear contraction of the tiles is reduced and
consequently, losses due to imperfections in size are decreased. This
helps in the production of large pieces. Lithium enhances the surface
quality of the tiles in terms of 'spot' resistance and
improves the mechanical characteristics.
Packaging and tableware
With increased glass demand, furnaces have been operating at close
to maximum capacity. Not surprisingly, as lithium is used to increase
effective furnace capacities, demand for lithium minerals increased
throughout 1996. In addition to increasing furnace output, lithium is
used to reduce melting temperatures and improve glass quality. In both
cases improvements of up to 10% have been observed, but results vary due
to differences in furnace
operations,
raw material mixes and the
compositional method of introducing lithium into the glass batch.
Recent trials in Europe have shown that it is possible to use
lithium to help to redistribute furnace energy. High cost electrical
energy has been reduced in favour of less expensive oil or gas,
resulting in lower melting costs.
Fritz and glazes
Lithium reduces the glaze viscosity and melting temperature as well
as decreasing the thermal expansion coefficient of the finished glaze.
It also improves the thermal and chemical stability of the finished
glaze.
Traditionally lithium carbonate has been the lithium source.
However, throughout 1996 there was a continuing trend towards replacing
lithium carbonate with lithium minerals, purely for cost saving
purposes.
TV glass
Throughout 1996, the rapidly expanding economies of India and China
have provided steady demand for lithium minerals in monochromatic TV
glass compositions.
For colour television applications, lithium is not such an
essential part of the composition but is being added, in some cases, to
provide a glass with a longer working range, or to increase effective
furnace capacities.
Glassfibre
There has been movement in the market towards an increase in the
use of lithium minerals in specific glassfibre applications. Acting as
part of a compositional package, lithium is incorporated into the glass
batch for the following reasons:
* To act as a flux and thereby lower the melting temperature of
decrease the required quantities of other costly raw materials.
* To increase glass surface tension and decrease viscosity,
improving the glass flow rate.
* To improve aqueous and acid durability.
New applications
Lithium forms part of the revised glass compositions of products as
more stringent
regulations,
covering both stack emissions and
permissible raw materials, particularly fluorine and lead, for glass and
glaze compositions worldwide are implemented.
Lighting, glassfibre, lead crystal and glaze producers are moving
towards commercial production of glass compositions which have totally
eliminated or reduced the volumes of these so called environmentally
unfriendly, but efficient, elements.
Pricing
Table IV reviews the relative costs of lithium minerals in
comparison to the traditional benchmark, lithium carbonate.
Table IV.
Material % [Li.sub.2] O Approximate price
(FOB sellers warehouse)
Lithium carbonate 40.4% US$1.15/lb
Spodumene concentrate 7.6% US$350/NT
Glass grade spodumene 5.0% US$170/NT
High alkine container
glass petalite 1.8% US$115/NT
Petalite 4.2% US$175/NT
Material Price per
Lb. [Li.sub.2] [O.sub.3]
Lithium carbonate US$1.15
Spodumene concentrate US$0.93
Glass grade spodumene US$0.68
High alkine container
glass petalite US$1.29(*)
Petalite US$0.84
(*) Does not include allowance for [Na.sub.2] O + [K.sub.2] 0
As lithium minerals are a relatively low cost commodity, the cost
of freight and storage forms a significant part of the delivered price
making general comments difficult. However the lithium minerals industry
has maintained a stable pricing structure over the past six years.
Forthcoming entry into the market of two new South American lithium
carbonate sources during 1997 has already started to put downward
pressure on lithium carbonate prices.
Table III.
Readily quantifiable Subjective or yet to
and established be quantified
Lower melting temperatures at Predicted decrease in furnace
equivalent furnace load NO2 emissions as a result of
and cullet lower temperatures.
Extended furnace life as a
result of lower temperatures.
Improved melt to pack ratio as
a result of reduced mold
swabbing.
Increased effective furnace No predicted increase in
capacity at equivalent cullet [NO.sub.2] emissions as cullet
without increasing melting furnace load increases.
temperatures.
Improved glass quality through
increased refining rates. Increased melt to pack ratio as
a result of the production of
Improved glass surface appearance. fewer checks and tears.
Reduced glass batch costs.
Mike Haigh, technical marketing
manager, Gwalia Consolidated Ltd,
Perth, Western Australia. Fax +61 8 9481 1271.
Derek J McCracken, manager, Industrial Minerals and Glass Raw
Materials, F&S International Incorporated, Pittsburgh, USA. Fax +1
412 787 8670.,
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