During the latter part of 2007, the management team of Lafarge Cendere Aggregate Plant in Istanbul, Turkey noted that they were experiencing high material costs resulting from the replacement of steel wire meshes in their screening plants. High operational costs were due to operational breakdowns during the change of the steel wire screening media in their final product screens.
Birol Bozkurt, the manager of the Lafarge plant, found when production was at the highest levels that the steel wire meshes in the first and second decks were not lasting more than a month.
The steel screening media was having difficulty in processing the main volcanic sandstone product (Wi=23, 6 and Ai=0, 21) at the plant, as it can be wet and sticky during the rainy seasons. The capacity of the screen averages 150 tonnes per hour (tph), which can increase up to 250 tph in periods of high production, with the screens being used in the production of 800,000 to 1.5 million tonnes of aggregates on an annual basis.
The first step for Lafarge was to contact Sandvik in Turkey, as Lafarge were aware that there have been some exciting developments in its screening technology. Eren Alp Ozol, sales manager of crushing and screening at SMC Turkey, and Dirk Vander Elst, sales manager of wear protection and screening media for Sandvik in South and Eastern Europe, had already been in contact about the latest developments in Sandvik?s screening media product range. Lafarge was interested in these developments and a meeting was arranged for the Sandvik team to visit the site and propose a solution to Lafarge?s problem.
After initial inspections of the existing situation, the use of WM6000 (former Stepdeck) for the first deck, and WM4000 (former Flexdeck) for the second deck were decided upon.
The first deck was designed to use 15mm thick WM6000 modules with 27mm square holes, while 8mm thick WM4000 modules with 15mm square holes covered the second deck. The installation was completed in March 2008 by the SMC Turkey engineering team.
As the existing screen was built for conventional screening media, the installation was mainly focused on the conversion of the structure to a modular system, with the conversion work being completed in three working days.
The focus was then to assess the performance of the new screening media. Sandvik had guaranteed a considerable difference compared to steel wire, with the difference producing savings that would be in excess of the initial investment in converting the plant to modular screening system and media.
The final scheduled inspection visit to the plant was in early December 2009, almost 20 months after installation and conversion to the modular system. Bilal Ekici, Lafarge Cendere?s plant quality technician, declared the conversion a great success.
?We have only stopped the screen to change some spare parts, and to add lubricants,? he explained. ?We have not needed to replace the screening media since the installation.?
The screen is currently working at a throughput of 150 to 250 tph, and since the installation not even a single module has had to be replaced in either of the decks. This has been quite spectacular progress, especially in comparison to the steel wire mesh panel?s performance.
Lafarge plant manager Birol Bozkurt is extremely pleased with the current state of affairs. ?We changed from a cheaper product to a comparatively quite expensive product for our screen panels,? he said. ?The result today proves this was the correct decision, and has resulted in a high reduction of operating costs, both in supplying the screening media, and also in reduction of downtime due to replacement times.?
He further adds that in Lafarge?s Cendere Plant, where all the crushers and screens are from the Sandvik range, the modular screening media has become ?the number one performing product, and that?s in comparison with the best products available on the market today?.
The OYAK Group purchased the plant at the beginning of 2010.
Source: Sandvik Mining and Construction