Sunday, 27 September 2009
Environs of Adelaide
Sunday, 20 September 2009
Industrial Tour- Part 3
We spent so much time on this that we didn't have time for our last port of call- a gas stabilisation plant at Port Bonython. It can just be seen across the gulf from Whyalla on this photograph. It was no particular loss to me- it can't be very different from Shell Mossmorran. But the students don't get too much exposure to more traditional Chemical Engineering and it was a pity they missed it.
Friday, 11 September 2009
Industrial Tour- Part 2
Back in the bus, we headed north about 200km to Port Pirie, the home of Nyrstar Ltd. This is a major refiner of lead, zinc, copper and precious metals. I have a beautiful aerial picture of the plant, but can't seem to get it down here. No matter- it's not really as beautiful as it is made to appear.
The process is as follows. (Non- Chemical Engineers switch off)
A feedstock made up mainly of lead concentrate is fed into a sintering machine. Other raw materials may be added, including iron, silica, limestone flux, coke, soda ash, pyrite, zinc, caustic, and particulates gathered from pollution control devices. The sintering feed, along with coke, is fed into a blast furnace for reducing, where the carbon also acts as a fuel and smelts the lead-containing materials. The molten lead flows to the bottom of the furnace, where four layers form: “speiss” (the lightest material, basically arsenic and antimony), “matte” (copper sulfide and other metal sulfides), blast furnace slag (primarily silicates), and lead bullion (98% by weight). All layers are then drained off. The speiss and matte are sold to copper smelters for recovery of copper and precious metals. The blast furnace slag, which contains zinc, iron, silica, and lime, is stored in piles and is partially recycled. Sulfur oxide emissions are generated in blast furnaces from small quantities of residual lead sulfide and lead sulfates in the ore.
The whole thing is a great deal more complex- the zinc is recovered by reducing the slag and copper is hydrometallurgically and then electrolytically refined. I've got the flow diagrams if anyone is interested. There is also significant production of silver and cadmium as byproducts.
The plant is the major employer locally and environmental concerns are very real. They have a campaign to reduce the lead concentration in the residents' blood to below 10ppb, for example. If it were a new plant, there's be a lot more protests. But they can't do without it.
This is a view which doesn't include the plant and does take in the Flinders ranges- but the weather was a bit poor for photography.
We headed next round the head of the Spencer Gulf, which is the big inlet you can see on the maps cutting into the centre of the South coast of Australia. This is the bridge across the head of the gulf.
Next stop was OneSteel at Whyalla. It's situated in this rather remote region because there's abundant iron ore in three separate deposits within 20 miles. It's brought in using hydrotransport in pipelines. They're very proud that it was a major site of Australian shipbuilding during the war (steel close, good deep water anchorages and as far from Japan as it's possible to be in Australia.) The corvette is memorial to this activity- completely dead now.
Update
She will be staying in Dublin a few days longer to sort things out in her mother's house before it is put on the market. She will then set off for California to stay with her sister and attend her nephew's wedding in Paso Robles, arriving back in Adelaide early in October.
The effect of all this on the blog is that she has the camera with her and, therefore, there will be no new pictures until she gets back. Blogs will be either purely verbal, like this one, or retrospective- like the next.
Friday, 4 September 2009
South Australia tour- first leg
On leaving Adelaide we crossed the River Murray at Murray Bridge and then cut towards the coast, going through a wetlands district called the Coorong which is where the Murray discharges into a series of coastal lagoons, the latter rather under stress. Their salinity has increased markedly due to over-abstraction of water upstream in Victoria and NSW.
The first plant we visited was a paper mill and tissue products factory (Kimberley Clarke) at Millicent. What we saw was the tissue forming and packaging side- more interesting to mechanical than chemical engineers. The pulp mill would have been a better visit and this will be arranged next year.
Here's a picture of the front of the bus and the students- not markedly different from any other student year worldwide. This lot in particular are a rather good advertisement for Australia- responsible, intelligent and friendly (but don't let on that I said so.)
From Mount Gambier, we returned to Adelaide via Wynn's Coonawarra winery. This was not very busy when we were there, as the workload is at its greatest at the grape harvest time. They take on a lot of seasonal labour and the technology is deliberately selected to make training easier. The person who took us round had encyclopedic knowledge of the wine business. What I learned was:
(1) unlike European wines, it is not legal to use extraneous enzymes to help the fermentation of Australian wines. On the other hand, it's quite legal to add tartaric acid to adjust the pH and even sugars to increase the initial gravity. This accounts for the very high alcoholic content of some of the local products.
(2) The difference between whites and reds is that the former are imemdiately filtered after crushing and before fermentation, whereas the latter ferment with the skins. So there is a higher filtration cost with the whites. They are also subject to chilling and sedimentation processes after fermentation to remove as far as possible the proteins that lead to clouding.
(3) They don't recover the CO2. This would only be attractive if they produced much more sparkling wine than in fact they do.
The only photos were taken at the very hospitable tasting session after the tour.... I make no apology for the anorak. It was really quite cold.