Extracting limestone and processing quicklime products for various sectors of industry form the portfolio of the Wuppertal-based company Oetelshofen Kalk. 75 % of its products are supplied by road or rail to local industry in a radius of 80 km. Around 100 000 tpa limestone flour is supplied, for example, to the flue gas desulphurization plants of the power stations along the River Rhine. Annual production currently totals 2 mill. t. To maintain this output rate and ensure environmentally compatible production in the future too, Oetelshofen has made some investments – in new firing technology from QualiCal as well as wear protection and noise control systems from Sandvik.
“In a pilot project, we have installed new firing technology at our facility. With an efficiency rate of 90 %, the PFR kiln (parallel flow regenerative principle) has attracted worldwide attention,” reports Moritz Iseke, Managing Director and great-grandson of the company founder. In addition, great importance has been attached to reducing noise emissions. And for that reason, the company contacted Sandvik. The company could draw on first, positive experience with Sandvik WT7000 rubber wear plates (Fig. 1) installed six months previously as part of the lining of an around 6 m2 larger hopper for the kiln feed. Key features of the modular system are easy fitting of the plates and the reduction of the noise level by around 20 dB. The human ear perceives this as a 50-% reduction in noise emissions. Convinced by this, the company management opted to fit the new 120 m2 tipping hopper with WT7000 rubber plates (Fig. 2).
It was essential to select the right material to meet the demands and requirements of the hopper, which is designed to handle around 500 000 t rock per year. After a planning and consultation phase, the company decided to buy 1 500 rubber plates, in a thickness of 50 mm, attached with welded studs, to meet the requirements for up to 60 t rock per trough, with a particle size up to 140 mm. If the sharp-edged rock does cause any damage, this can be quickly remedied, at low cost and without any danger, by the easy replacement of individual plates, each plate weighing 5 kg and measuring 300 x 300 mm in size.
“The base element of the hopper is protected against cracks and deformation by the patented modular plate system, it remains in its original shape, the special lip on the plates avoids the ingress of fines into any gaps, and the at least three times longer service life is another plus. You won’t get these advantages from conventional solutions with metal or composite materials,” explains Selim Sahin from Sandvik. The 100-% rubber plates boast other advantages, like, for example, simple cutting and high environmental compatibility thanks to being made from recyclable material. In addition, the quarry is home to the biggest population of eagle owls in Europe. With double-shift operation in the quarry, the nocturnal hunters are also grateful to Sandvik for peace and quiet during the day.
Sandvik Mining and Construction Central Europe GmbH, Essen (D), Selim Sahin, Sales Manager Wear Protection/Screening Media, Tel. +49 201 1785-361,
E-Mail: firstname.lastname@example.org, www.sandvik.com