Washing experts say waste stockpiles are the key to unlocking full potential of an operation.
As the rate of global resource extraction continues to accelerate, finite natural materials continue to deplete, and barriers to gain approval for new mineral extraction sites mount, CDE is encouraging materials producers to reappraise their waste streams to get more value from their operations.
Sand and aggregates are amongst the most important resources for everyday life. They’re needed for the construction of the roads and pathways we travel on, the buildings we live and work in, the microchips powering our technology, and so much more. They are indispensable resources for modern living, yet they are finite and require careful resource management.
In 2018, mineral wastes and soils accounted for 63% of total waste generation in the UK[i], meanwhile the latest Global Resources Outlook report, published by the United Nations Environment Programme, suggests resource extraction could rise by 60% to 160 billion tonnes over the next three decades[ii].
Uncovering Buried Profits
Mining and quarrying operations generate significant volumes of waste by-product as part of their process but within these waste streams there is opportunity to repurpose the overburden, scalpings, and crushed rock fines that come as part of the mining and quarrying process.
Where overburden concerns the clay-bound top layers of soil and subsoil above bedrock that are removed as quarries and mines expand, scalpings are the contaminated stones removed during primary screening in dry processing plants, and crushed rock fines are a by-product of the dry rock crushing process, which typically produces a low-value product with very high fines content.
Old materials, new opportunities
The traditional approach to managing waste by-product such as overburden, scalpings, and crushed rock fines is to stockpile them on site, which is generally symptomatic of the limitations of the technology employed on site at the time.
CDE’s patented washing and processing allows quarry operators to transform unwanted waste materials that may have been sent to landfill into high-value sand and aggregate products that can be sold straight off the belt.
Longcliffe Quarries, based in Derbyshire, had historically discarded its clay-bound limestone scalpings, but feasibility studies and material testing found a market for products recovered from this waste stream.
Powered by a 220 tonnes per hour (tph) state-of-the-art CDE wet processing plant, up to six different products are being extracted from clay-contaminated material, which is creating new, high-value revenue streams and helping reduce net emissions on site.
Conventional dry processing equipment has its drawbacks with quarry waste by-products, which typically have high clay and fines content, but advances in washing technology is shown to overcome these challenges to produce high-quality sand and aggregates and maximise product yield from quarry waste.
Recently, CDE designed and engineered such a solution to support Peter Fitzpatrick Ltd, a quarrying and contracting company based in Northern Ireland, to reprocess excess crushed rock fines and blinding material at its quarry in Newry. Processing up to 130tph of quarry waste overburden per hour, the CDE wash plant is enabling the firm to produce five saleable outputs, including: concrete sand, 6mm grit, 10mm, 20mm, and +20mm aggregates.
Commenting on the value of repurposing waste streams, CDE’s William Melanophy, head of business development for the UK and Ireland, says: “Too often these masses are categorised as ‘waste’ or low value material when in reality they possess significant potential to quarry operators. When processed with the right technology, most of these seemingly low-quality by-products can be marketed quite profitably.
“It is crucial we start to maximise the available reserves and tackle more complex material. CDE is committed to providing solutions which address the industry’s waste burden in a bid to meet the everyday needs of our customers”.
For more information about CDE and its washing solutions for tackling quarry waste, visit CDEGroup.com.
