Manufactured sand success in Norway
In 2008, the Norwegian quarry Velde Pukk made a bold decision to invest in a unique, complete manufactured sand process, making use of air classification technology. Today, in close cooperation with Metso, the quarry runs a highly successful sand plant, serving the region’s concrete and asphalt industries with high-quality manufactured sand.
Run by three brothers, Harald, Egil and Reidar Velde, Velde Pukk operates a highly sustainable and efficient quarry, industrial sand-making, ready-mix concrete and asphalt production. The key elements of the quarry’s success include the correct rock type, a sophisticated plant control system, efficient logistics and a company-owned R&D laboratory.
Located on the outskirts of the Norwegian oil city Stavanger, Velde Pukk is a pioneer in the production of manufactured sand in Norway and Europe. Globally, the only comparable process that makes use of the fractionizing of fine sands and dry air classifying is found in the US.
“Even though the aggregates production plant is the heart of our operation, we prefer to be called an industrial park rather than a quarry. With our investment in manufactured sand, we changed our focus from being an aggregates supplier to a problem solver,” says Managing Director Egil Velde.
“With manufactured sand, it’s all about consistent moisture, gradation and shape. After a lot of testing, we can now say with confidence that Velde Pukk can accurately achieve the gradation that our customers require for their asphalt and concrete production.”
“The future of cement aggregates”
Superior particle shape, consistent gradation and the flexibility to balance the sand mix with the air classified fines, accurately and according to the customer’s needs, are the main benefits of the manufactured sand.
Local cement producers in Stavanger have achieved cement savings of up to 10–15% using manufactured sand. In pre-tensioned concrete element production, manufactured sand also provides faster hardening compared to natural sand.
Spenncon, a Stavanger-based, regional producer of pre-tensioned concrete elements, made the switch from natural sand to Velde Pukk’s manufactured sand in August 2009 and has used about 5,000 tons per month ever since. The plant has found the change to be quite positive.
“Based on the experience gained in concrete element manufacturing, we can really see that the future of aggregates for the concrete industry is in manufactured sand. It contains a constant, stable quality and gives us better control of our element production,” says Spenncon’s Plant Manager Tore Aasen.
According to Aasen, the plant now requires 10% less cement for the production of concrete.
“In addition, the pre-tensioned elements now reach high strength 30 minutes earlier that when using natural sand. This has a positive impact on our productivity,” he adds.