En los últimos años, la minería se ha enfrentado a una disminución paulatina del precio de los metales, generando una reducción de la rentabilidad del negocio producto de menores reservas minerales. Esto ha ocasionado que se adopten esquemas operativos enfocados en la mejora continua de cada uno de los procesos dentro del ciclo de minado, a fin de reducir los costos. Por tal motivo, es necesario visualizar cada una de las actividades involucradas, como la perforación y voladura, las cuales tienen un impacto productivo y económico en el proceso global. En consecuencia, la presente investigación se enfoca en optimizar la fragmentación de rocas, a través de un diseño de malla de perforación y voladura, mediante la integración de los conceptos de ingeniería de la voladura y caracterización del macizo rocoso. Para esto, se aplicará el modelo matemático de Pearse, a fin de calcular los parámetros controlables del diseño y obtener los resultados esperados. Asimismo, el alcance del trabajo abarca el análisis de la productividad del ciclo de minado, así como, la cuantificación del impacto de la propuesta en materia de costos. Se comienza con el análisis de línea base, que consta de la medición de resultados producto de los diseños actuales de malla de P&V, con la finalidad de determinar las variables que están generando fragmentación gruesa de rocas. Posteriormente, se plantea la propuesta de diseño de malla considerando la mayor cantidad de datos e información del tajo Tacaza. Luego se ejecutan los trabajos en campo, que consta del seguimiento y control de actividades, a fin de cumplir con los parámetros diseñados. Finalmente, se miden los resultados de fragmentación en el software Wipfrag, y se analiza la productividad y costos en el ciclo de minado. De los resultados se obtiene una mejora en la fragmentación, ya que se logra reducir el diámetro de rocas de 13.0 a 5.0 pulgadas en promedio. Esto conlleva a un incremento en el rendimiento efectivo de los equipos y una reducción de costos de US$ 9,600 mensuales aproximadamente. Estas nuevas medidas generan valor agregado a la compañía, a través de una operación minera sostenible, que busca hacer rentable el negocio desde una visión holística del proceso. / In recent years, mining has faced a gradual decrease in the metal´s prices, generating a reduction in the profitability of the business as a result of lower mineral reserves. This has led to the adoption of operational schemes focused on the continuous improvement of each of the processes within the mining cycle, in order to reduce costs. For this reason, it is necessary to visualize each of the activities involved, such as drilling and blasting, which have a productive and economic impact on the global process. Consequently, this research focuses on optimizing rock fragmentation, through a drill and blast mesh design, by integrating the engineering concepts of blasting and characterization of the rock mass. For this, the Pearse mathematical model will be applied, in order to calculate the controllable parameters of the design and obtain the expected results. Likewise, the scope of the work includes the analysis of the productivity of the mining cycle, as well as the quantification of the impact of the proposal in terms of costs. It begins with the baseline analysis, which consists of measuring the results of current P&V mesh designs, in order to determine the variables that are generating coarse rock fragmentation. Subsequently, the mesh design proposal is proposed considering the greater amount of data and information from the Tacaza pit. Then the field work is carried out, consisting of the monitoring and control of activities, in order to comply with the designed parameters. Finally, the fragmentation results are measured in the Wipfrag software, and the productivity and costs in the mining cycle are analyzed. From the results, an improvement in fragmentation is obtained, since it is possible to reduce the diameter of rocks from 13.0 to 5.0 inches on average. This leads to an increase in the effective performance of the equipment and a cost reduction of approximately US $ 9,600 per month. These new measures generate added value for the company, through a sustainable mining operation, which seeks to make the business profitable from a holistic view of the process. / Tesis

The Nigeria economy is wholly dependent on revenue from oil. However, bitumen has been discovered in the country since 1903 and has remained untapped over the years. The need for the country to complement oil exploration with the huge bitumen deposit cannot be overemphasized. This will help to improve the country's gross domestic product (GDP) and revenue available to government. Bitumen is classifled as heavy crude with API (American petroleum Institute) number ranging between 50 and 110 and occurs in Nigeria, Canada, Saudi Arabia, Venezuela etc from which petroleum products could be derived. This dissertation looked at the Canadian experience by comparing the oil and tar sand deposit found in Canada with particular reference to Athabasca (Grosmont, Wabiskaw McMurray and Nsiku) with that in Nigeria with a view of transferring process technology from Canada to Nigeria. The Nigeria and Athabasca tar sands occur in the same type of environment. These are the deltaic, fluvial marine deposit in an incised valley with similar reservoir, chemical and physical properties. However, the Nigeria tar sand is more asphaltenic and also contains more resin and as such will yield more product volume during hydro cracking albeit more acidic. The differences in the components (viscosity, resin and asphaltenes contents, sulphur and heavy metal contents) of the tar sands is within the limit of technology adaptation. Any of the technologies used in Athabasca, Canada is adaptable to Nigeria according to the findings of this research. The techno-economics of some of the process technologies are. x-rayed using the PTAC (petroleum technology alliance Canada) technology recovery model in order to obtain their unit cost for Nigeria bitumen. The unit cost of processed bitumen adopting steam assisted gravity drainage (SAGD), in situ combustion (ISC) and cyclic steam stimulation (CSS) process technology is 40.59, 25.00 and 44.14 Canadian dollars respectively. The unit cost in Canada using the same process technology is 57.27, 25.00 and 61.33 Canadian dollars respectively. The unit cost in Nigeria is substantively lesser than in Canada. A trade off is thereafter done using life cycle costing so as to select the best process technology for the Nigeria oil/tar sands. The net present value/internal rate of return is found to be B$3,062/36.35% for steam assisted gravity drainage, B$I,570124.51 % for cyclic steam stimulation and B$3,503/39.64% for in situ combustion. Though in situ combustion returned the highest net present value and internal rate of return, it proved not to be the best option for Nigeria due to environmental concern and response time to production. The best viable option for the Nigeria tar sand was then deemed to be steam assisted gravity drainage. An integrated oil strategy coupled with cogeneration using MSAR was also seen to considerably amplify the benefits accruable from bitumen exploration; therefore, an investment in bitumen exploration in Nigeria is a wise economic decision. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2010.

The Nigeria economy is wholly dependent on revenue from oil. However, bitumen has been discovered in the country since 1903 and has remained untapped over the years. The need for the country to complement oil exploration with the huge bitumen deposit cannot be overemphasized. This will help to improve the country's gross domestic product (GDP) and revenue available to government. Bitumen is classifled as heavy crude with API (American petroleum Institute) number ranging between 50 and 110 and occurs in Nigeria, Canada, Saudi Arabia, Venezuela etc from which petroleum products could be derived. This dissertation looked at the Canadian experience by comparing the oil and tar sand deposit found in Canada with particular reference to Athabasca (Grosmont, Wabiskaw McMurray and Nsiku) with that in Nigeria with a view of transferring process technology from Canada to Nigeria. The Nigeria and Athabasca tar sands occur in the same type of environment. These are the deltaic, fluvial marine deposit in an incised valley with similar reservoir, chemical and physical properties. However, the Nigeria tar sand is more asphaltenic and also contains more resin and as such will yield more product volume during hydro cracking albeit more acidic. The differences in the components (viscosity, resin and asphaltenes contents, sulphur and heavy metal contents) of the tar sands is within the limit of technology adaptation. Any of the technologies used in Athabasca, Canada is adaptable to Nigeria according to the findings of this research. The techno-economics of some of the process technologies are. x-rayed using the PTAC (petroleum technology alliance Canada) technology recovery model in order to obtain their unit cost for Nigeria bitumen. The unit cost of processed bitumen adopting steam assisted gravity drainage (SAGD), in situ combustion (ISC) and cyclic steam stimulation (CSS) process technology is 40.59, 25.00 and 44.14 Canadian dollars respectively. The unit cost in Canada using the same process technology is 57.27, 25.00 and 61.33 Canadian dollars respectively. The unit cost in Nigeria is substantively lesser than in Canada. A trade off is thereafter done using life cycle costing so as to select the best process technology for the Nigeria oil/tar sands. The net present value/internal rate of return is found to be B$3,062/36.35% for steam assisted gravity drainage, B$I,570124.51 % for cyclic steam stimulation and B$3,503/39.64% for in situ combustion. Though in situ combustion returned the highest net present value and internal rate of return, it proved not to be the best option for Nigeria due to environmental concern and response time to production. The best viable option for the Nigeria tar sand was then deemed to be steam assisted gravity drainage. An integrated oil strategy coupled with cogeneration using MSAR was also seen to considerably amplify the benefits accruable from bitumen exploration; therefore, an investment in bitumen exploration in Nigeria is a wise economic decision. / Thesis (M.Ing. (Development and Management))--North-West University, Potchefstroom Campus, 2010.