Prince Minerals - developing a reliable solution for abrasive materials

At its site in Stoke-on-Trent, Prince Minerals Limited, a leading international processor of speciality industrial minerals, mills silica sands to produce powders. Milled silica is transported by bucket elevator from the ball mill up through the building so that it can fall under gravity through a desk sieve, and then onto an  air classifier.

Cost-effective in terms of initial capital outlay and energy efficiency, bucket elevators are a sound choice for this application but Prince Minerals had encountered a number of reliability-related issues with an earlier system. In a recent upgrading project the brief to Guttridge and SGH Equipment, the project engineers responsible for installation, was to engineer a solution that would significantly enhance reliability.

The highly abrasive nature of milled silica makes this a relatively demanding application. To tackle it, Guttridge designed and manufactured a system with a number of special features calculated to deliver the low maintenance, high reliability solution required. These included:

• Steel buckets with wear resistant metal bands to extend working life.
• Hardox wear plates on the inlet and outlet of the conveyor to minimise wear in these high throughput areas.
• A cage and cone boot pulley system to prevent material getting in between the pulley and the belt and causing damage.
• Stand off bearings with integral air purge to prevent the ingress of dust into the bearings and enhance reliability.
• Larger casings to reduce the risk of material build up and the likelihood of damage to the buckets in the event of any belt tracking problems.

This solution runs smoothly with minimal attention and has eliminated the reliability issues encountered with previously installed systems. Features such as these may, in some instances, add extra cost, but over the long run deliver the reliability that operators increasingly require. Understanding not simply what options are available, but exactly when they are needed, delivers significant value to the customer.