Lanning of quarrying operations of ornamental stones in northern portugal by using cut-off grade as a criterion of quality control(Article)

The planning of quarrying operations of ornamental stones has unfortunately not achieved much success, in the past, in relation to quarry planning and control. The present paper presents an innovative methodology utilizing the concept of cut-off grade as a quality control criterion of nepheline syenite production in the Monqchiue quarry during the production of ornamental stones blocks of four different qualities. This innovative management approach is considered to be the first successful attempt of ornamental stone quarry management with excellent results.