Glendinning boosts sustainability credentials through sand manufacturing

EJW Glendinning, the Devon based independent supplier of quarrying and concrete products, has successfully begun manufacturing sand from limestone at its Linhay Quarry in Ashburton, Devon. The use of a CV217 VSI from Sandvik Construction has enabled the company to successfully produce sand for its own requirements, and in the future, it is hoped to offer the manufactured sand to other cement manufacturers.

Ernest and Jack Glendinning acquired Linhay Hill Quarry in 1958, showing a passion and commitment to the industry and their customers which is as prevalent today as it was then. Since then, the company has gone from strength to strength, becoming a commercially successful concern whilst retaining the integrity of a true 'family business'. This has been achieved with a strong sense of pride that has driven the company forward, providing a foundation to the way it operates, the quality of its products and services, whilst enabling it to continually look for improvements to enhance its own and its customers’ operations.

Today, Glendinning is still wholly owned by the founders' families, with many family members remaining actively involved in the day to day running of the business. The company can also be said to be a ‘family’ business in the broader context of the word, as it employs over 230 predominantly local people. This is essential to the Glendinning business model, as it is a company that relies on teamwork, loyalty and a strong sense of community, with generations of the same families being employed. It is this sense of community, with an ongoing commitment to training and locality that ensures that Glendinning is able to continue to provide the very highest levels of service to its many thousands of customers.

Glendinning’s limestone quarry at Linhay Hill, Ashburton in Devon, is where the main hub of the business operates from, and has been in operation since the company purchased it in 1958. From here Glendinning has for over half a century supplied aggregates, ready-mix concrete, asphalt, blocks, paving, sand and lime for new roads and highways maintenance, as well as providing the materials for the construction of schools, homes and hospitals and agricultural use. Expansion of the business now sees it operate across six sites in Devon - Ashburton, Exeter, Paignton and Plymouth - and one in Cornwall, Pigsdon Quarry near Bude.

The local focus of the Group is reflected in Glendinning’s customers who are predominantly located in the Exeter, Teignbridge, Torbay and the Plymouth areas. These customers include approximately 1,800 small building firms, as well as the general public for home improvements materials and, increasingly, larger national concerns. The sheer variety of products the company is able to supply means that it is able to also cater for the requirements of various local authorities, major construction companies and house builders, civil engineering contractors, national and regional builders’ merchants, as well as agricultural merchants and farmers.

One reason for Glendinning’s success in catering to the varied requirements of the local market is the company’s local knowledge. This enables the supplying of aggregates specifically for local construction projects, which are the most suitable for the task at hand. Hence Glendinning is pleased and able to advise on materials to fit with the requirements of any given project, then through its own transport fleet, is able to supply the materials where they are required in a highly cost effective manner.

As well as the Linhay Hill quarry, Glendinning also owns a highly successful gritstone quarry at Pigsdon. Here the company is able supply a broad range of crushed rocks for aggregate and other associated requirements. Production at the quarry has been enhanced through the use of mobile crushing and screening equipment from Sandvik Construction. This comprises of a tracked cone crusher, as well as two highly productive new generations tracked screens.

It was through discussions with Sandvik, who had previously supplied mobile equipment to Glendinning, which led to the acquisition of a new, state of the art VSI, which is proving to be invaluable in the manufacture of sand for Glendinning’s concrete operations. Through its ready-mix business, which is based around Exeter, Plymouth and Ashburton, the company is able to comprehensively supply the Devon construction market. The manufactured sand has had to be of a high quality as all of Glendinning’s ready-mixed concrete products conform to BS EN 206 and BS 8500-2 performance criteria, and are quality assured through ISO 9001 accreditation.
This focus on quality has also seen Glendinning at the forefront of endeavours to demonstrate sustainability credentials by adopting the principals of the WRAP protocol. As well as sourcing quality waste arising’s, the company’s wide range of products assist in contributing towards environmental assessments. These commitments towards sustainability are backed by the ISO 14001 environmental accreditation.

These ongoing processes of quality, and enhancing environmental considerations, were major reasons behind Glendinning beginning manufacturing its own sand from limestone aggregate at the Linhay Hill quarry. For many years the company has been able to supply a limited range of sands from its quarries, but customer demand has also seen it import a range of different sands. Glendinning has produced a washed limestone sand for many years, but on a limited scale only, producing sufficient volumes to supply its own in-house concrete plants. However, recent technological advances in crusher design by Sandvik Construction have enabled Glendinning to produce much greater quantities on shorter production hours through the use of a CV217 VSI, therefore enabling the company to explore the external market.

Introduced in 2002, Sandvik’s line of autogenous crushers utilise a rock lined rotor to accelerate material. This is then impacted in a highly energized rock lined crushing chamber which impacts with material falling through the biflow system. The crushers incorporate the Sandvik Hurricane™ rotor, which became a major breakthrough in VSI autogenous rotor design due to its decreased vibration levels and wear part design. This results in increased crusher bearing life combined with reduced maintenance.

The CV217 was principally chosen for its ability to crush feed material in order to produce a high quality sand product, of a consistent small size, at high rates of production. Hence Glendinning’s CV217 is now being fed a minus 40mm limestone product which then produces a minus 5mm “sand”. The VSI is able to process between 50/60tph of the manufactured sand end product. The manufactured sand is currently being used for internal concrete production, but when the operation is in full swing it is hoped that it will be offered to external customers as well.

Richard Webb, Glendinning’s Operations Manager, Quarrying and Concrete Products, says of the sand manufacturing process: “Although the VSI is now working to expectations, and ideal for our own requirements, it is not yet producing the grading’s that we require if we are to offer the manufactured sand to other cement manufacturers. New cyclones from MEP (Mineral Engineering Processes) are due to be installed in the very near future and through their use we hope to produce manufactured sand that is the equal to, if not superior to, naturally occurring sand.”

The modern design and construction of the CV217 produces additional benefits for Glendinning as its 2nd generation rotor and wear parts allows for greater production, but using less power, for a more efficient and environmentally focused operation. Furthermore as it mirrors nature’s action using rock-on-rock action for breakage, the VSI uses fewer parts, meaning a reduction in spare parts replacement during the operational life time of the production facility, thereby maximizing investment. All of these factors mean that Glendinning is able to maximise its existing limestone resource, produce a valuable cost efficient sand product for its own use, and continue to operate in a more environmentally focused manner.