Combining mechanochemistry and innovative diamond wire saws for improving productivity in granite quarries.

Granite quarrying technology has evolved from the rock breaking techniques borrowed from mining technology to specifically designed techniques that rely on diamond wire for cutting the rock. These advances have resulted in substantial improvements in productivity, waste reduction and safety, resulting in significant reductions in overall costs. Thanks to cooperation between machinery manufacturers and quarry operators, by the turn of the 20th century, granite quarrying had become an important contributor to Italy's economy. However, narrowing profit margins due to competition from foreign producers forced operators to take urgent remedial action. Over the last 10 years, major efforts have been devoted to improving granite-cutting techniques. These innovations have pursued two directions: improvement of the tool/rock interaction utilizing current knowledge about the effect of the physicochemical environment on rock breakage and improvements to rock cutting machinery from the study of innovative mechanical designs. The first approach relied on the exploitation of the mechanochemical effects discovered by the Russian scientist Rehbinder in the 1930s. This led to the development of a series of additives for reducing granite hardness, resulting in productivity increases of conventional and innovative granite block cutting machines ranging from 30 percent to 100 percent. Productivity enhancement of conventional diamond wire saws operating in plants and quarries were not so encouraging, probably because of the lack or flexibility of their mechanical adjustment devices. The second approach was pursued by a manufacturer who patented an innovative, hydraulically powered diamond wire saw, achieving productivity enhancements of up to 50 percent as a result of its efficient performance. The specific features of these machines lend themselves well to optimization of performance in terms of mechanochemical applications. Productivity increases in diamond cutting performance of between 15 percent and 40 percent were achieved daring a patent validation campaign carried out in four granite quarries in Northern Sardinia and financed by C21, a public agency for fostering synergies between academia and industry. [ABSTRACT FROM AUTHOR]