[Music plays and text appears: Forging our future in green steel]
[Image changes to show foundry workers working with molten metal]
[Image changes to show Mark Cooksey, Group Leader, Sustainable Process Engineering]
Mark Cooksey: Steel making is one of the world’s largest industries and it produces over 300 million tonnes of slag every year. So slag is the waste product from iron making.
[Image changes to show the spinning disc for the slag granulation process and then moves back to Mark Cooksey]
At CSIRO we spent more than a decade working on advanced technology to deal with that slag in a way that’s more environmentally friendly.
[Image changes to zoom in on foundry workers working with a crucible of molten metal]
The current methods are dump it on the ground which is perfectly acceptable. It’s not hazardous but that means you waste a large amount of material that could be used for another use and you lose all the heat, a gigajoule of heat for every tonne of slag.
[Image changes to show Mark Cooksey]
The other way of dealing with slag is to granulate it using water.
[Image changes to show granules of slag being poured through the hands]
This produces good granules that can be used for cement manufacture.
[Image changes to show Mark Cooksey]
The trouble is you use 1,000 litres of water for every tonne of slag so that’s a large environmental cost.
[Images flash through of the process of dry slag granulation]
What we’ve developed here is dry slag granulation. We can granulate the slag, produce a good quality product that can be used for cement manufacture but do it in a way that doesn’t involve water.
[Image changes to show Mark Cooksey]
If you use our products to produce cement for each tonne you use you basically save 800 kilograms of CO2 emissions.
[Image changes to show Mark Cooksey in front of the spinning disc showing the process of moving slag into the spinning disc]
[Image changes to show the inside of the spinning disc]
Our dry slag granulation technology involves pouring molten slag from above our rig down to a spinning disc. That disc is spinning at high speed and it atomises the molten slag into small granules.
[Image changes to show molten slag being atomised and collected in the taurus]
They solidify as they are travelling through the air and are collected in a taurus that surrounds the disc. The really smart bit of the technology is the disc.
[Image changes to show Mark Cooksey]
That involved a lot of computer modelling and design to come up with a disc that can produce consistent granules reliably. Other people that have worked on this technology have struggled with that part of the process.
[Image changes to show two smaller images one of the disc and the other of the molten slag being atomised and then moves back to Mark Cooksey]
Air is used to blow the granules around the taurus. The granules are ultimately collected from various points and the hot air is extracted out of the top and that’s how we recover the heat energy.
[Image changes to show Prof Gang Wei, Director, China Engagement for CSIRO Manufacturing and Minerals Flagships]
Prof. Gang Wei: We have developed in partnership with a Chinese company M.C.C.E. Through this collaboration we can commercialise CSIRO needing technology to benefit both nations through reducing carbon dioxide emission and to save water and most importantly recover energy as well. And at the end of the day it’s a global benefit for the society.
[Image changes to show Jonathan Law, Director, Mineral Resources Flagship]
[Image changes to show the M.C.C.E. webpage]
[Image changes to show Jonathan Law, Director, Mineral Resources Flagship]
Jonathan Law: We’ll be working with a company called M.C.C.E. in China. China produces 50% of the world’s steel and they will be developing a pilot facility at one of the Chinese steel facilities to test this technology and then to take it to market, first in China but ultimately around the world.
[Camera zooms in on the M.C.C.E. webpage]
This collaboration could be really important for a number of reasons.
[Image changes to show steel works]
Firstly it brings Chinese production technologies together with Australian science and secondly if implemented around the world it’ll have a huge impact on water and energy use and greenhouse gas emissions.
[Image changes to show Jonathan Law, Director, Mineral Resources Flagship]
[Image changes to show street lights along a road to the city]
Just to give you an example, if this technology was deployed everywhere in the world it would equate to about 14% of Australia’s annual energy usage, about 10% of Australia’s greenhouse gas emissions.
[Image changes to show the CSIRO webpage]
The success is based on the CSIRO flagship programme.
[Image changes to show Jonathan Law, Director, Mineral Resources Flagship]
This lets us think strategically about what the important technologies Australia and the world will need in the future and dry slag granulation is a great example of us thinking about a demand in the future, working with our scientific collaborators to get the technology to a commercial ready stage and now we’re ready to commercialise it.
[Music plays and text appears: CSIRO Big ideas start here, www.csiro.au]
The process, known as Dry Slag Granulation, also reduces water use and greenhouse gas emissions, and is the focus of an agreement signed by CSIRO and the Beijing MCC Equipment Research & Design Corporation (MCCE).
The signing of the agreement, to demonstrate CSIRO’s Dry Slag Granulation (DSG) technology at industrial scale, is a landmark for Australia-China research collaboration and for environmentally friendly metal production, according to CSIRO Director of the Mineral Resources Flagship, Jonathan Law.
“Our collaboration is an exciting step towards the uptake of an innovation with real prospects of transforming the productivity and environmental performance of global iron smelting,” Mr Law said.
“The benefits from wide uptake of DSG technology on blast furnaces will be profound in helping the global industry to reduce water and energy use and greenhouse gas emissions while sustaining metal production.”
The DSG technology that is fitted to blast furnaces includes a spinning disc and granulation chamber that separates molten slag into droplets under centrifugal forces, uses air to quench and solidify the droplets, and extracts a granulated slag product as well as heated air.
The process produces a ‘glassy’ product that is ideal for cement manufacture, but has significantly lower associated greenhouse gas emissions than cement produced by conventional methods.
Air at 500-600°C extracted from the DSG process can be used onsite for drying, preheating or steam generation.
The technology also saves water and eliminates the underground water pollution that can be associated with alternative wet granulation processes.
“The benefits each year from full commercialisation and adoption of DSG technology are in the order of 60 billion litres of water, 800 petajoules of heat energy and 60 million tonnes of greenhouse gas emissions,” Mr Law said.
“Those savings are equivalent to 14 per cent of Australia’s energy use and about 10 per cent of our greenhouse gas emissions each year.”
In entering the collaboration with MCCE, CSIRO has recognised the R&D reputation of the Beijing-based company and its ability to scale-up the technology and introduce it into China - where 60 per cent of the world’s 300 million tonnes of iron blast furnace slag is produced each year.
Under the agreement MCCE is to scale-up and demonstrate the technology at industrial scale and, upon success, commercialise it in China and then potentially worldwide.
The agreement is the culmination of more than a decade of DSG technology development by CSIRO and industry partners including Arrium and BlueScope.
This work covered initial design and proof of concept stages through to the construction and operation of prototype DSG pilot plants at small, intermediate and large scales.
“DSG is just one of the CSIRO innovations in sustainable steel production and one of many solutions we have found for national and global challenges in the minerals industry,” Mr Law said.
“The DSG project is a good example of reward from continuous R&D investment and we look forward to working closely with MCCE to bring it to full fruition.”
