Modelamento informatizado da lavra de rochas ornamentais: granito Casablanca.

Abstract

The primary objective of this dissertation is to verify the conditions of application of a block modeling software, already with wide and proven use in the modeling of mineral deposits and mines in operation, for the specific case of an ornamental granite - Casablanca Granite , located in the State of Ceara. In the alternative, the work aims to review and consolidate the techniques for collecting and analyzing geological and geotechnical data relevant to the activity of extraction of ornamental granites, through a case study. The research involved the steps: bibliographic review, data collection in the field, data analysis, computer implementation and interpretation. The bibliographic review includes: general aspects the mining of ornamental rocks; geology and other characteristics of the area surrounding the quarry chosen for the study; and about previous research focused on the application of programs aimed at modeling ornamental stone deposits. The collection and analysis of data in the quarry area involved a plani-altimetric survey and a detailed measurement of the foliation of the massif by measurements made on the mining fronts. Subvertical fractures were raised and plotted on the concession area, but have not yet been detected in the quarry area. Fractures of relief were not incorporated into the model due to the lack of outcrops at the time of field. The computer deployment phase consisted of digitizing the topography of the quarry area. The quarry reserve was then modeled with blocks in dimensions suitable for the Company's looms (3.30m by 1.90m by 1.60m), using the DATAMINE application. A model was made with a horizontal cut of the blocks, resulting in a reserve of 19,201 blocks (78% recovery), having been considered as sterile the rock partitions in the periphery of the model that do not reach the standardized dimensions. A second model simulated blocks cut at an angle of 32 ° in relation to the horizontal, according to the foliation of the rock, resulting in 19,571 blocks (81% recovery). It is important to emphasize that the reserve calculated here will be reduced, in view of the defects always present in the rock, causing the disposal of blocks without commercial value for use as ornamental rock. The model using a lower-cut piano inclined to the blocks may be useful in those massifs presenting anisotropy or non-horizontal fractures, being one of the contributions of the present research. With the calculation of the block reserve and visualization of the quarry in several graphical output options, the data interpretation phase is complete. As a suggestion for future works we can mention: monitoring and simulation of the advance of the mining, with control of different rock varieties from the same quarry; side dish reserve blocks calculated by the software compared to the commercial value blocks removed, thus obtaining an estimate of mining recovery; quarry modeling with tablet division, as the previous phase of block modeling; and incorporation of physical and petrographic properties as regionalized variables aiming at geostatistical modeling.