A Holcim quarry in New South Wales’ Illawarra region gains commercial and sustainability advantages with the Kayasand V7-60 sand plant.
Holcim’s Albion Park quarry extracts and supplies hard rock and sand to the construction industry in the region as well as the wider Sydney market.
In the highly competitive market, plant efficiency is as important as product quality and consistency. Maximising the value of what’s extracted from the ground is critical to the long-term sustainability of the industry.
Holcim quarry manager Darren Essex spoke to Quarry about how Holcim gained an advantage with Kayasand’s V7-60 plant, increasing its saleable dust levels by about 50 to 60 per cent and creating value out of waste.
“We had two issues at the site,” said Essex.
“We wanted to reduce our crusher dust stockpiles and improve the shape of our manufactured sand.”
Only a small percentage of Albion Park’s crusher dust was being utilised in concrete.
The dust was both poorly shaped and high in 75 micron content, rendering it unsuitable for concrete applications above a 20 percent natural sand replacement.
Stockpiles were growing each year, so the decision was made to invest in new plant machinery and technology.
Kayasand ticked all the boxes for Holcim during the plant selection process, Essex said. Shape and consistency were big factors – most off the shelf plant technology that Holcim looked at tended to create a lot of fines and it was hard to get shape in the lower sieves.
“The V7-60 technology is cutting edge as far as improving shaping in a sand product. When you look at our product now, you see a noticeable improvement in its shape.”
The air screens that feed oversize material back through the plant ensure the end-product consistently meets specifications, while undersize dust particles are collected in a filler silo.
“Today we produce a better-quality product without an excessive amount of 75 micron by-product,” Essex said.
This of course is a highly desirable quality to the high-demand Sydney market, where large projects need reliable supplies.
“The Kayasand plant has been instrumental in us getting a significant portion of our manufactured sand into the Sydney market,” Essex said.
“In a market where you’ve got lots of other sand, it might not stack up so high. But in one that’s depleted of natural sands, or one with fine dune sand around to complement it, manufactured sand is a really good solution.”
To be sure the plant was going to benefit Albion Park, Kayasand sent Albion Park quarry samples to Japan.“The Japanese market seemed to be a bit further along in the use of manufactured sand,” Essex said.
“In fact, I heard of some examples using Kayasand’s plant to produce material at around 100 per cent replacement of natural sand.”
“I haven’t seen any other off the shelf plant achieving that level of replacement.”
Of course, selling more manufactured sand means less waste. In 2017 Holcim was awarded with the Environmental Innovation Award by Cement, Concrete and Aggregates Australia (CCAA) for dramatically reducing their dust stockpiles at Albion Park.
The Albion Park Quarry has reduced that waste even further by turning it into a value-added product.
“There’s a waste product that comes out of the Kayasand process that’s a dry 75 micron material,” Essex explained.
“We add that to asphalt dust and road base through a pugmill to improve our product quality. We’ve managed to use about 70 per cent of the by-product in other products.”
For more information, visit kayasand.com
This feature first appeared in the July issue of Quarry.