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30/06/2003
Project duration: 1st semester, 2003
Student: Kazuya Hosokawa, QUT B.Mechanical Engineering
BACKGROUND
Boral Bricks, part of the Boral Group, manufactures clay bricks and other ceramic products on their 64 hectare site at Darra. The company, originally Brittain Bricks and Pipes Limited, first made bricks in 1899 and became a subsidiary of Boral Limited in 1969.
The Darra plant contains 2 separate brick plants, producing over 90 million bricks per annum. About 10% of the raw materials (clay/shale) are mined within the Darra site and the remainder is mined around the Brisbane area. The raw materials are transported to Darra by trucks and stockpiled in a way that ensures the desired mixtures of raw materials area ready for processing.
As the Darra site is a mining site as well as a manufacturing site, the water runoff from the site carries relatively large amounts of clay and may contain contaminates, therefore cannot be directly discharged into the surrounding environment.
The runoff water is currently collected in large sediment ponds on-site, which theoretically, cannot cope with all the runoff water. Also, a large amount of town water is used during the manufacturing process and discharged into the atmosphere as vapour.
Victor Guerra, Process Manager at the Darra Plant recognised that the company needed a better understanding of the inputs/outputs related to water balance across the site. He wanted to quantify his “gut feel”. Victor believed that a CEED project would give Boral “an opportunity to groom a fresh mind to an old problem, giving a fresh perspective and allowing a different outcome”.
METHODOLOGY
Firstly, Kazuya conducted a water audit, which assessed the current water balance of the Darra site by looking at its water input such as rainfall and town water as well as water output such as water discharged into the environment from the manufacturing process, including water vapour discharged into the atmosphere. This was the most time consuming phase of the project, according to Kazuya. But he understood that it was crucial to accurately complete the audit before moving onto the analysis and, later, recommendations.
Secondly, he conducted a literature review about water management, treatment and recycling, which corresponded to the Darra site.
Finally, Kazuya presented a Site Water Management Plan to Boral, making ecological and economical recommendations for the future site water management, based on the water audit and literature review.
RESULTS
According to Victor Guerra, Kazuya’s final report was comprehensive. Boral now have tangible information that can be used as a platform for site optimisation.
A couple of Kazuya’s recommendations were:
· Utilisation of water collected from roof structures – recycle into the manufacturing process, contributing towards the required process water (plus reduce amount of town water used, i.e. less impact on local infrastructure and lower operating costs)
· Longer term – possible recycling of other sorts of water, eg: recycle gases from kilns & dryers back into the manufacturing process. This recommendation needs to be assessed for economic viability
Kazuya’s plan will now be presented to Boral management for consideration in line with their current review of environmental strategy.
The information contained in Kazuya’s report also serves as an information database for future site work, eg. water conservation. According to Victor Guerra, Kazuya’s report has “given perspective to the relative significance of various inputs/outputs and therefore what sort of priorities need to be exercised against each input output” – very valuable management information.