Standing the test of time

Paul Boughton

After five years and 15m tonnes of granite, ceramic linings have 'negligible' levels of wear.

The ongoing benefits to production and reliability of a well specified and designed wear protection system are being demonstrated at Lafarge’s super quarry at Mountsorrel in Quorn, Leicestershire, UK.

Five years ago, Kingfisher Industrial provided the combination of its K-BAS, cast basalt, and K-ALOX ceramic linings to the sides and discharge sections of a number of storage bins at the quarry.

The installation was recently inspected as part of Kingfisher’s 10-year warranty, and was found to have negligible levels of wear, despite having handled over 15-million tonnes of the hardest type of granite over the previous five-year period.

The problem the company faced in achieving this objective was the nature of the material itself. The granite handled at Mountsorrel is among the hardest known. [Page Break]

Storage hoppers

Unfortunately, this fact was brought home by the excessive levels of wear being experienced in the storage hoppers and conveyor transfer points at the railhead.

The existing steel and rubber liners used within the system were not lasting six months, due to the high levels of impact and sliding induced abrasion from handling of the granite

Clearly, greater service life from the chosen lining system was required if throughput from the hoppers and the transfer system was to be increased: and this increased life would also mean reduced maintenance of the plant.

When Kingfisher surveyed the hoppers it saw that a two-stage wear protection system was required. The top section of the sloping walls of the storage hoppers were subject to sliding abrasion, but the bottom sloping walls and discharge sections suffer from both sliding and impact induced abrasion.[Page Break]

Ceramic liners

The combination chosen had proven itself over long periods in very demanding applications. It comprised of 40mm thick K-BAS, cast basalt lining, for the top sloping section of the hopper sides, and 50mm thick 92P K-ALOX ceramic liners on the high wear areas in the bottom sloping and discharge chute sections.

The K-BAS fused basalt lining is designed for conveying and storage systems that require high resistance to friction induced abrasion. The material has an extremely hard and smooth surface, which offers the added advantage of improving material flow.

The 92P K-ALOX liner used in the discharge section is in the form of high alumina ceramic tiles. These are easy to shape and fit, and have a smooth low-friction surface that progressively polishes during use, preventing material build-up and improving material flow.

After detailed planning, engineering and procurement of raw materials Kingfisher engineers installed the lining system on all 20 storage hoppers and various transfer chutes, during a shutdown period in compliance with CDM regulations and Lafarge’s strict safety culture.

Five years later, the warranty inspection was due, to identify any areas of concern. This was carried out in late February 2012, and the findings were highly satisfactory.

The installation looked largely ‘as new’; the only difference from the initial installation being the highly polished nature of the lining surfaces, thus assisting material discharge.
 
Fig. 1. A granite conveyor.

Fig. 2. Discharge section of holding hopper from granite at Mountsorrel.

Fig. 3. Granite storage hopper.

Fig. 4. Feed system for storage hoppers.

Fig. 5. Kingfisher A-LOX ceramic lined systems.

Fig. 6. Conveyor feed systems for storage hoppers.

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