# Blasting Fragmentation Study Using 3D Image Analysis of a Hard Rock Mine
of trucks, by the truck hauling time over short distances, by the hauling productivity, or by the productivity of primary crushing [10; 11; 16]. The evaluation of blasting fragmentation by defining the particle size distribution curve has been performed via image analysis using equipment and software available on the market, such as Split-Desktop [1; 12; 15], WipFrag [2; 17; 18], and Fragblast PortaMetricsTM [17; 18; 19; 20]. These technologies have no limitation on the sizes of the samples that can be analyzed. The errors inherent to the method can be minimized by capturing many high-quality images for analysis [2]. Some of these methods require the use of a scale object to help determine the sizes of the fragments, which may require the presence of humans in the field and may not be the safest alternative. Some methods have better data processing than other equipment available on the market, providing immediate and accurate fragmentation analysis [18]. A well-known example of the distribution of rock fragmentation analysis, known as RFD, is currently widely used in order to simulate and optimize drilling and blasting operations, with this movement being reflected even in the primary stages of crushing. An example is the operations of the Sarcheshmeh copper mine [1]. It is worth mentioning that the increase in the amount of material to be fragmented increases the cost of drilling and reduces loading and transportation costs. However, there are problems that can be generated from the definition of mining to be adopted, such as the need for secondary and even tertiary blasting [1; 17; 18]. According to [1], when using Split-Desktop software, seeking the analysis of fragmentation using the RFD method, five steps are necessary, which are image dimensioning, the automatic or manual limitation of the fragments, the estimation of fines, the evaluation of the results, and the export of the analysis result to a Kuz-Ram curve plotted in Excel, demonstrated in the work performed by the same authors, with an d80 of 13.06 cm and a d50 of 6.48 cm, post-blasting. In the work developed using the same method in [12; 15], it was possible to delimit the effectiveness of the method in the dismantling carried out, analyzing the size of the fragment and the effect of loading through the operational variables. It was possible to observe that the Kuz-Ram method, for such a methodology, overestimated the RFD from coarser granulometry and underestimated the fine granulometry. In addition, the Split-Desktop method involves at least five steps, which are considered to be the following: sizing the image, segmenting the fragments, the possibility of editing the fragments, analyzing the marked parts, and the distribution diagram of size [4]. Another technique that is widely used is the analysis of fragmentations via WipFrag with the help of the empirical model of Kuz-Ram. In the work developed by [2], when developing a project for the evaluation and optimization of blasting, images captured from a Muck pile were used. The results obtained by the method can vary significantly; therefore, three tests were carried out, and all of which presented satisfactory and similar results. However, it is worth noting that the Kuz-Ram model presents idealistic results due to the variation in rock characteristics, being widely used for the preliminary assessment of blasting [2]. When describing the operation of the equipment [17; 18], a post-dismantling 2D cam-corder is used to record images of the dismantled pile. For the record to be conducted efficiently, photos must be taken from different angles, and the image must be transformed into a fragmentation map. This equipment is considered to be good for more superficial analyses, mainly generated via underground mine dismantling, with the possibility of using PortaMetrics as a more efficient method for open pit mining [18].