Lakhasly

Diamond blade produces smoother slabs, but presents greater problems of linearity, especially in the case of very hard rocks.The magnetic fraction includes metals covered by the European Union CRM (Critical Raw Material), so their recovery is essential.The technology with diamond wire seems to be the best, both for slabs productivity and for the low percentage of metals in the sludge that can be recycled as it is. Instead, the sludge produced with the frame saw technology has high percentages of Cr, Ni, and Cu, requiring magnetic separation before its reuse.In this way it is possible to obtain two fractions that can be recovered separately.

Diamond blade produces smoother slabs, but presents greater problems of linearity, especially in the case of very hard rocks. It produces more sludge than the other technologies.
The technology with diamond wire seems to be the best, both for slabs productivity and for the low percentage of metals in the sludge that can be recycled as it is. Instead, the sludge produced with the frame saw technology has high percentages of Cr, Ni, and Cu, requiring magnetic separation before its reuse.
The magnetic separation could be part of the ‘normal industrial practice’, indicated by the legislation, as it does not change the status of the waste, but simply makes a separation. In this way it is possible to obtain two fractions that can be recovered separately. The magnetic fraction includes metals covered by the European Union CRM (Critical Raw Material), so their recovery is essential. For example, taking into account the M1 sludge sample obtained from frame saw cutting, the quantities involved are: of 1800 t of sludge produced in a year, 3% is composed of CRM, corresponding to 54 t a year for only one plant. Taking into account that, in Piedmont alone in the year 2015, there were 29,149 t of stone sludge produced, making the average percentage of metals present 2%, a total of 583 t of CRM metals could be recovered, instead of going to special landfills.