Aplicação do método RQD para análise do quartzito bacarat da mina Coreaú

Abstract

The ornamental stone market is one of the mining sectors that has shown great growth in Bra- zil. Several Brazilian states have the production of ornamental rocks with different character- istics, although in the same lithology, as well as having difficulty in the exploitation of each material, given the geological conditions of each mine. At the same time, there is a constant market demand for new products that adapt to the needs of use. From such perspectives, there is a mine in operation in Ceará with the production of white quartzite, commercially called Bacarat. It has in its mining process some difficulties related to the presence of cracks, at the same time it plans to expand the mining fronts and, for that, it carried out a drilling campaign, in order to carry out a structural analysis of the cores recovered through the method RQD and analysis of material characteristics in terms of color. Thus, once the drill cores were recovered and analyzed, the material was classified, according to the parameters of the method, as frag- ile and quite fragile, being generally below 25%, a condition attributed to the families of joints and cracks identified on the faces of the material throughout the entire geological body. At the same time, the recovered material presented, in general, the same characteristics of the mined material regarding the white tone. In this way, the mining should tend to a vertical pat- tern, while mechanisms available on the market are proposed that enhance recovery and pro- duction, such as the enveloping of blocks and benches, the reduction of the cutting height of the latter and also the variation of the sequence. of cuts with diamond wire to detach the benches.