The building boom of the recent years has created an exceptional demand for concrete as a major building material. Water use is a big challenge for the concrete industry. Clearmake helps to solve it.
Clearmake’s customer Hanson Concrete (formerly Pioneer) was able to increase its turnover by 9.8%. More and more concrete batching plants grow out of the ground and with them an increasing demand for raw materials – one of them, water. While the water used for concrete batching is mostly bound in the concrete and lost, water plays an important role in many other areas of the operation.
On a daily basis the East Perth Concrete Batching Plant uses about 25 KL of water for the washout of their 18 trucks. The annual concrete production is about 120,000 m3 which is delivered in lots of 0.6 – 6.8 m3. Before Hanson engaged Wave Engineering to develop a concept for the reclamation of their wash down water, they used two 40 KL settling pits, which needed to be pumped out every 2-3 days.
The annual cost for the sludge / waste water handling was about $ 60,000. In addition, the requirements for additional growing business required more space which was not available.
“Replacing the existing sludge beds with the Clearmake Treatment System had many positive effects for us,” Stuart Wright, Operations Manager at Hanson, East Perth says.
Based on Wave Engineering’s analysis, Clearmake designed a system which was implemented in November, 2005 and since has been slightly changed and significantly improved. The wash down waste water contains a significant amount of aggregate and sand larger than 1 mm.
In the first step, this waste stream gets put through a “Trommel” rotating screen, which separates the larger solids (which are reused in the batching process). The water goes from there to a holding tank from which the system pumps the water into the treatment phase. After treatment, the water is put back into a storage tank, from where it is pumped back for wash down and batching.
“When Hanson looked for a system, there was nothing in the market,” Reg Chaponnel, Clearmake’s Chief Engineer says. “Sludge handling and timing were the biggest challenges. Once we got them right, the system worked very well. The water Quality is actually very good and we were even able to reduce the requirements for pH adjustment and treatment chemicals (Flocculants).”