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Development of a diamond wire capable of cutting limestone/ chert economically

Investigation into why state-of-the-art diamond tools cannot
cut limestone/chert mixtures economically by analysing the
construction, diamond-bond structure and machine parameters
and subsequently develop the appropriate tool.

FEELYSTONE KILKENNY quarry and process limestone in the quarries located in Paulstown, Co. Kilkenny. Limestone is a sedimentary rock and there is quarried in its naturally occurring beds. In some of these beds there are deposits of chert, which occur normally in bands but which can also occur randomly in a bed. This chert is a very abrasive/ hard stone that causes excessive wear to the tools that are used to quarry and process it. FEELYSTONE KILKENNY quarry the limestone and then process the blocks into slabs, or finished pieces. To date we have quarried 19 beds of limestone of which 8 have contained chert. This chert usually occurs in horizontal bands in the beds, which allows them to quarry the block and then turn it vertically. By turning the block vertically, we can saw each side of the band of chert. In this situation we incur between 33% and 50% waste from the block. In more recently opened beds, the chert has occurred in thicker bands and in the last bed that we opened, the chert occurred randomly throughout the bed. In these beds we have incurred wastage figures of between 66% and 100%. When using diamond wire to cut limestone, the production figures are usually in the region of 40-45 square metres of stone cut, per metre of wire used. When these wires are used in beds which contain chert, the average production figures fall drastically to about 6-10 square metres of stone cut per metre of wire used. This is more than a 400% decrease in the productivity of the wire. Since chert causes so much wear to the diamond tools, it is uneconomic to process and thus material which contains chert becomes waste. Unfortunately, though, to get to the better beds of stone in the quarry, we have to quarry through the beds containing chert and thus endure the added cost of doing so. Limestone which contains chert is perfectly sound and suitable for construction work. This means that by developing this product correctly, we would both decrease our cost of quarrying and also make a present waste stone into a marketable product. Working with BUDIAM Diamond Tools, a German tool manufacturer, on a joint venture we would hope to develop the required diamond tool. We have a long working relationship with this firm and the company has both the expertise and machinery to develop the required diamond wire. At present the type of wire that we use has been developed for the Belgian market. This means that it is not ideally suited to Irish limestone, because it is slightly different to that of BELGIUM. In this project we are proposing to develop a diamond wire that will be specifically developed for Irish limestone and the flint contained in this limestone. The results should be beneficial to the Irish limestone industry as a whole.
Acronym: 
CHERT
Project ID: 
1 612
Start date: 
01-09-1996
Project Duration: 
24months
Project costs: 
340 000.00€
Technological Area: 
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.