Capability brochure
April 2016
Salt
Symbolic and sustainable
Capability brochure
Salt
Capability brochure
Salt
April 2016
April 2016
Our salt business
Rio Tinto, through its 68.4 per cent owned subsidiary, Dampier Salt Limited
(DSL), is the world’s largest salt exporter. Producing salt at three locations in
Western Australia: Dampier, Port Hedland and Lake MacLeod. Dampier Salt
is headquartered in Perth, Western Australia and its sales, marketing and
logistics are performed in Singapore.
From our operations in
the Western Australian
Pilbara, we produce
in excess of ten million
tonnes for export every
year.
The Dampier operation was the first DSL
site established in 1967 and is currently the
largest producer of the three sites, with a
capacity of 4.2 million tonnes per annum.
including alumina and polyvinyl chloride
(PVC). DSL salt products are also used
as food salt and for general purposes
including road de-icing.
The Port Hedland operation was acquired in
2001 and has a current production capacity
of 3.2 million tonnes per annum.
Sun and wind energy comprise around
99 per cent of the total energy required
to grow, process and ship DSL salt. The
sustainability strategy is founded on longterm operational viability and maximising
the use of renewable energy sources. This
is a story we are proud to tell in a world that
recognises greenhouse gas emissions are
contributing to climate change
The Lake MacLeod site was acquired in
1978 with a current production capacity of
2.7 million tonnes per annum.
DSL’s salt customers are in Asia and the
Middle East. The majority are chemical
companies who use salt as feedstock for
the production of chlorine and caustic soda,
together known as chlor-alkali production.
These are used in the manufacture of
many chemicals and downstream products
The Lake MacLeod and Port Hedland
operations have been harvesting salt for over
40 years. The demonstrated sustainability
of DSL’s approach indicates that operations
will continue well beyond the next 40 years.
Capability brochure
Salt
April 2016
Capability brochure
Salt
April 2016
Producing salt
Dampier Salt’s operations are all self-renewing as they use seawater and brine to
replenish supply.
The total area under
evaporation at DSL salt
operations is 19,500
hectares, equivalent to
27,900 football fields.
At our Dampier and Port Hedland
operations the salt is produced from
seawater. The seawater is pumped into the
operation and flows through a series of
ponds.
Evaporation, due to the energy of the
sun and assisted by the wind, results in
the water becoming progressively more
concentrated. When this brine is saturated
with salt (sodium chloride) it is pumped
into crystallising ponds (crystallisers)
where further evaporation causes pure
Sodium Chloride (NaCl) to crystallise as a
solid deposit.
The same processes for crystallisation,
harvesting, washing, stockpiling and ship
loading used at Dampier and Port Hedland
are used at Lake MacLeod. The Lake
MacLeod salt is shipped from dedicated
facilities at the port of Cape Cuvier.
Approximately once a year, each crystalliser
is harvested by a mechanical harvester
after 20 to 40 centimetres of salt has been
deposited.
The salt is then washed to remove
impurities and stockpiled for shipment.
Dedicated stockpile and ship-loading
facilities are located at Mistaken Island
(Dampier) and the port of Port Hedland.
At Lake MacLeod, the brine is naturally
concentrated sea water recovered from
a shallow aquifer below the dry lake bed.
We do not mine the salt – we grow it.
At every stage of the process we use
natural processes and renewable sources of
energy to move, grow and harvest the salt.
Capability brochure
Salt
April 2016
The majority of salt we produce at DSL
is supplied to the chemical industry for
production of chlorine, sodium hydroxide
(caustic soda) and sodium carbonate
(soda ash). These chemicals are then used
in the processing and manufacturing of
other products across the automotive,
construction and electronic industries.
Today salt is so common, so easy to obtain
and so inexpensive that it is easy to forget
that from the beginning of civilisation until
about 100 years ago, when modern geology
revealed its prevalence, salt was one of the
most sought after commodities in human
history.
Scientists believe that the harvesting of
salt from salt water dates back at least
8,000 years. A substance so valuable it
served as currency, salt has influenced
the establishment of trade routes and
cities, provoked and financed wars, secured
empires and inspired revolutions.
Across the ages and religions the ability of
salt to preserve, to protect against decay
and to sustain life, has given it a broad
metaphorical importance. Loyalty and
friendship are sealed with salt; truth and
wisdom are associated with salt and ancient
Roman soldiers were paid with special
money that could be used to purchase salt.
This special money was called salarium,
from which we get our modern word
“salary.” In fact, salt was so expensive
during the Middle Ages that it was often
called “white gold.”
April 2016
The caustic soda, chlorine
and soda ash our salt is used
to produce makes a massive
difference to the everyday
lives of people around the
world
Using salt
Dampier Salt maintains
a market leadership
position by bringing
benefits to customers
that include a
sustainable, reliable
and high quality supply
of salt
Capability brochure
Salt
Our final product – clean, white,
coarse salt crystals – is used by the
chemical industry and food markets
to make products vital for modern
life.
• glass where soda ash added to the
glass lowers the melting temperature
• detergents and soaps contain soda ash
or caustic soda
• textiles use caustic soda to break down
plant fibres, chlorine to bleach cloth
and salt to fix some dye colours
A smaller percentage of our salt is used in
food processing and some for de-icing of
roads in winter.
• industrial chemicals such as
The main end uses of our salt include:
• chlorine based plastics such as PVC and
polyurethane, which is used as insulation
in refrigeration and air conditioning
systems to reduce energy use
• food processing
hypochlorite bleach, plastic pre-cursor
chemicals and caustic soda
• road de-icing by lowering the freezing
point of ice on the roads
2
3
1
Sites
1
Port Hedland
2
Dampier
3
Lake MacLeod
Our salt operations
We operate three separate salt operations in the hot, dry climate of Western
Australia which is a region ideal for solar salt production.
Our early growth was
fuelled by the chemical
industry in Japan,
Taiwan and Korea –
and these customers
remain vital to us, as
do newer markets like
China.
The three site operating strategy, well
executed stock management policy and
freight strategy, provides greater security,
flexibility and confidence in supply to suit
our customers’ needs.
The total area under evaporation at
DSL salt operations is 19,500 hectares,
equivalent to 27,900 football fields. The
three sites evaporate an average of 1.1
billion litres of water a day, enough to fill
18,000 domestic swimming pools. Rio
Tinto’s share of salt production by DSL is
over six million tonnes a year.
Each operation operates an advanced
laboratory for quality control purposes
with processes which continually monitor
product quality. This is particularly
important during the movement of brine
through the pond and crystalliser systems.
It takes about 50 million tonnes
of seawater to produce one million
tonnes of salt
Rio Tinto plc
6 St Jame’s Square
London SW1Y 4AD
United Kingdom
Rio Tinto Limited
120 Collins Street
Melbourne, Victoria 3000
Australia
T +44 (0)20 7781 2000
T +61 (0)3 9283 3333
riotinto.com