Grains Research and Development

Date: 01.04.2002

How's this for diversification? $$ opportunities in salinity

FERTILISERS, pesticides, plastics, soaps, detergents and dyes from saline groundwater?

Been hitting the grog again, you say? Well, a new CSIRO study, taking a 'can do' approach, has listed these possibilities and a lot more. According to Hal Aral of CSIRO Minerals, substances dissolved in our salty ground waters can be used to make fertilisers, light metals, plastics, industrial chemicals, oil refining, pesticides, glass, fibre glass, ceramics, bleach, soaps, detergents, dyes, inks, sewage treatment, sugar refining, alcohol brewing - "the list is almost-endless".

Focusing on the embattled Murray-Darling Basin, Dr Aral and colleague Graham Sparrow are proposing new industries to extract valuable raw materials from the groundwater, using natural evaporation and solar energy.

For instance, ordinary salt can be crystallised out of groundwater by evaporation, then used to make chlorine, hydrochloric acid, sodium hydroxide, sodium metal, soda ash, sodium bicarbonate and table salt. Among these are substances that can be used in the processing of titanium and zirconia.

Once the salt is removed the water, known as 'bittern', still contains magnesium, potassium, sulphates, boron, strontium, bromine, iodine and other useful compounds. These range from epsom salts, worth $400-$800/ tonne, to fertiliser ingredients, cement ingredients and many other chemicals even more valuable. Bittern can be directly used in the mining industry as a dust suppressant.

The Aral plan envisions the widespread recovery of salts from saline evaporation ponds. A network of solar-powered desalination plants and energy storage ponds across the Murray-Darling Basin can then convert highly saline waters to fresh water for local communities and value-added chemicals for industry.

Solar benefit

"By generating solar energy and using solar ponds to store it, we can also make a serious move towards renewable energy use in regional Australia," Dr Sparrow says.

The plan also links into the development of major titanium and mineral sands industries in the Basin, based on the existing $13 billion resource and using value-added salts in the processing. Titanium, in turn, can be used to make corrosion-resistant parts for desalination plants.

"The Murray- Darling Basin could, potentially, become the centre of an Australian sustainable chemical industry - drawing on a vast natural resource, and integrating production so that one industry uses the waste products of another."

Dr Sparrow estimates that an early stage industry adding value to Murray- Darling salt could be worth $200 million a year, as well as helping to lower the threat to the heartland's water quality and farming industries.

If nothing is done about salinity in the Murray-Darling Basin, in 20 years Adelaide's water will be undrinkable and in 50 years the river water will be toxic to most crops, By 2100 the whole system will be carrying 10 million tonnes of salt a year.

Contact: Mr Michael Chapman. CSIRO Minerals 0409190 321 web site: www.minerals.csiro.au

Region North, South, West