Search Stories by: 

Recycling, Crushing, Screens & Feeders, Mobile Plant, Load & Haul

Articles from CRUSHERS PLANT & EQUIPMENT (665 Articles), SCREENING PLANT & EQUIPMENT (591 Articles), MOBILE CRUSHERS (447 Articles)

Recycled aggregates: a solution to future demand, says industry leader

Delta Group has been one of the leading Australian companies to promote alternative quarry products as quarries experience difficulties meeting booming infrastructure demand. Damian Christie spoke to James Georgiou about the company’s recycled aggregates division.

Since 1974, Delta Group has engaged in industrial demolition projects across Australia. Its core activities have included civil works, excavation, landscaping, commercial bin hire and heavy equipment hire. Its clients have included construction companies, government departments, municipal councils and developers.

In the past three decades, Delta’s demolition division has been involved in some of Australia’s landmark redevelopments in and around Australia’s capital cities. These include the Canberra International Airport, Melbourne’s Crown Casino promenade, Amcor paper mill and the Melbourne Convention and Exhibition Centre/South Wharf redevelopment, the International Convention Centre and Wynyard Place in Sydney, the Queens Wharf development and Lady Cilento’s Children’s Hospital in Brisbane, and the Fiona Stanley Hospital, the Cockburn cement plant and the Kwinana power station in Perth.

The company has also been involved in numerous regional projects, including the Hazelwood mine and power station and Balmoral Quay (Victoria), the Woodsreef mine and Kurri Kurri aluminium smelter (New South Wales), the Abbot Point coal terminal (Queensland), the Kimberley Clark mill (South Australia), and BHP sites at Boodarie and Nelson Point (Western Australia).

Delta’s “impressive fleet” consists of primary, secondary and tertiary jaw and cone crushers, impactors, screens and stacker conveyors.
Delta’s “impressive fleet” consists of primary, secondary and tertiary jaw and cone crushers, impactors, screens and stacker conveyors.

Impressive output

Delta Group actively recycles more than 90 per cent of all the materials it collects from its demolition projects, including non-reusable ferrous and non-ferrous materials, salvaged metal and steel, timber and, of course, concrete and other construction materials.

The company became involved in the recycled construction materials business in 1999. This market is only slightly older than the company itself – no more than 30 years – and today, Delta, along with the likes of the Alex Fraser Group and Benedict Industries, is considered a leader in recycled concrete materials, which is believed in Melbourne alone to have an output of two to three million tonnes per year.

In fact, James Georgiou, Delta’s project manager of concrete recycling and contract crushing, estimates that Delta’s fixed and mobile recycling operations are “capable of processing more than one million tonnes per year in the Melbourne Metro area alone”.

Delta’s concrete recycling division has enjoyed a very successful joint venture (JV) with Boral Quarries in Victoria and New South Wales to crush, process and treat commercial demolished concrete into a product called Envirocrete, which functions as an approved substitute for crushed virgin quarry rock. Envirocrete is typically used as a pavement material for roadworks, carparks, factory sites and landscaping.

“Envirocrete is a VicRoads-approved substitute for virgin quarry crushed rock,” Georgiou said. “It can be supplied in classes 2, 3 and 4, wet- and cement-treated, if required. It is largely utilised in applications such as base and sub-base layers under concrete and road works, hardstands, backfilling and capping.

“Envirocrete has been supplied to many high profile projects across Melbourne. These include but are not limited to freeway and highway upgrades, level crossing removal projects, pipeline renewals and large volumes of subdivision work.”

The Delta/Boral partnership encompasses a fixed concrete recycling plant, as well as mobile operations at multiple sites elsewhere in Melbourne and Sydney.

“Our impressive fleet consists of jaw and cone crushers capable of primary, secondary and tertiary applications, impactors, screens, stacker conveyors and earthmoving gear of all sizes and capabilities, effectively increasing our scope of work,” Georgiou said of the concrete recycling division’s mobile plant and earthmoving operations.

The total output of Delta’s Group’s Australia-wide concrete recycling operations exceeds one million tonnes annually. Delta not only crushes and processes the recycled concrete aggregate from its demolition projects but also accepts construction and demolition (C&D) materials from other demolition and civil contractors, infrastructure suppliers, and major projects at sites throughout Melbourne and Sydney. It will also crush overburden and waste rock generated in quarries, and this is steadily becoming a lucrative part of its business.

“Our contract crushing arm of the business has never been healthier,” Georgiou said. “We regularly service the major quarry players across the Melbourne Metro area by providing the additional supply required to meet their sales demands. Delta has extensive experience in producing materials like concrete and asphalt aggregates, rail ballast, crushed rock, rubbles and toppings.”

It is believed the total output of Delta’s Group’s Australia-wide concrete recycling operations (including its Sunshine plant, pictured) exceeds one million tonnes annually.
It is believed the total output of Delta’s Group’s Australia-wide concrete recycling operations (including its Sunshine plant, pictured) exceeds one million tonnes annually.

Recycled vs Virgin

The theory goes that if C&D materials can be recycled in close proximity to infrastructure projects, then there is a significant saving in terms of the extraction and cartage of virgin materials. While it is difficult to quantify exactly what the measurable savings are (between one and three million tonnes per year in Melbourne alone is hardly something to be dismissed), Georgiou says savings can be found more in the processing steps, not just the quantities of extracted rock.

“There’s always a difference in the cost of crushed concrete versus hard rock,” Georgiou said. “This is generally due to the resources involved in getting the virgin rock prepared for crushing, that is, drilling and blasting, hammering and hauling. Concrete raw feed [in a recycling operation] on the other hand is accepted free of charge and tipped off in an adjacent area to the crushing plant.”

Otherwise, Georgiou doesn’t see much divergence between the quarrying and recycled aggregates industries. “Both streams operate quite similarly, except for the rubbish extraction process, which requires the addition of picking labour to ensure the cleanest finished product,” he explained.

“We regularly rotate our resources within both divisions of concrete recycling and contract crushing as the objectives are very much the same in appropriately preparing the raw material and then processing it with a majority of the same machinery,” Georgiou added. “The main difference really [is] the steel reinforcement and rubbish extraction requirement when processing demolition waste.”

Georgiou anticipates that there will be significant growth in the recycled aggregates market, “for as long as the country’s population continues to grow and requires further infrastructure improvement. We can clearly foresee a drastic increase in the demand for recycled materials across Melbourne in the very near future,” he added, attributing this to the commencement of major projects and a shortage of readily available quarry materials across Victoria to meet construction demand (the reserves are there, it’s simply the speed and time to process them is not).

Nevertheless, Georgiou is optimistic about the ability of the quarrying and recycled aggregates sectors to collaborate and innovate as “plant and equipment continues to improve with new operational systems and technology”.

“Should recycling plants digitise and automate to the point where this process can be carried out to the same standard without manual labour, both operational systems will be seen to converge further,” he said.

Delta Group recycles more than 90 per cent of all the materials it collects from its demolition projects.
Delta Group recycles more than 90 per cent of all the materials it collects from its demolition projects.

Damian Christie
Editor • Quarry Magazine

Damian Christie is the editor and a chief writer of Quarry magazine. To contact Damian, please click here.

Sunday, 22 July, 2018 09:01pm
login to my account
Username: Password:
Free Sign Up

Receive FREE newsletter and alerts