CEMEX – Kingsmead case study

Material source:

Stone rich sand and gravel from a 2.5 million tonne supply.

Project requirements:

To redevelop an existing site that had come to the end of its useful life, using new plant with the capacity to process up to 300,000 tonnes a year from a stone-rich dig.

Duo’s solution:

Duo installed a new washing and crushing system, based on a simple modular arrangement. Raw materials derived from a wet dig dragline excavation could be drained, Powerscreened, rinse screened, and crushed to create 10 mm, 20 mm and sharp washed sand products together with a 40 mm single size product – materials that are used for Cemex’s own concrete production and commercial sale.

Project success:

The design, manufacture and installation of the fixed conveyors including the installation of a fully galvanised heavy gauge steelwork with guarding throughout, has increased Cemex’s throughput to 150tph.

As the company’s South East Director of Aggregates Matt Wild explains: “If we were to do a 40 down product, we can up the quantity by about 20% to 180 tph, however the best balance between mass and quality of product is 150 tph – providing our optimum throughput.”

Working flexibility has also improved significantly with the use of screen modules which are easily switched from producing 20 mm, 10 mm and sharp washed sand, to making the 40 mm product.
The system’s dewatering screen speeds up drying, as it allows the sand to drain and be loaded out within 3-4 hours, as opposed to one or two days.

Furthermore, a feed conveyor enables Cemex to stockpile materials as a failsafe when the production situation requires.