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En la presente tesis se estudia la aplicación de los principios matemáticos de Holmberg y sus colaboradores. Dichos principios se encuentran descritos en el libro Rock blasting and explosives engineering que tiene como finalidad demostrar de manera práctica la importancia de realizar un adecuado diseño de la malla de perforación y voladura. Esto se llevó acabo, en primer lugar, con el mapeo geomecánico (RMR), el análisis del arranque a utilizar, así como la longitud de barrenos y el explosivo óptimo para el cebo y la columna de carga. Esta investigación se realizó en la Unidad Minera Santa María de Compañía Minera Poderosa S.A., donde se demostró que el cambio de diámetro en los taladros de alivio del arranque de 38 mm a 64 mm y el uso adicional de barrenos de 8 pies para la sección de 2.5 m x 2.7 m, contribuye a ser eficientes en cada disparo. En esta misma instancia, se demostró que, aplicando de manera óptima los principios matemáticos utilizados se puede reducir notablemente la cantidad del uso de explosivos, viéndose reflejado en un ahorro económico por disparo. Los resultados obtenidos con el nuevo diseño son: el factor de potencia pasó de 1.23 a 1.15 kg/t reduciendo un 6.8 %, el avance por disparo de 1.51 a 2.10 m aumentando un 39.2 % y el factor de carga lineal de 23.24 a 21.02 kg/m reduciendo un 9.6 %; lo cual se traduce en un ahorro mensual por frente de trabajo de S/. 21,421.12. / This thesis explores the application of the mathematical principles of Holmberg and his collaborators.These principles are described in the book Rock blasting and explosives engineering which aims to demonstrate in a practical way the importance of proper drilling and blasting mesh design. This was completed, first of all, with geomechanical mapping (RMR), analysis of the start to be used, as well as the length of holes and the optimal explosive for the bait and the loading column. This research was carried out at the Santa María Mining Unit of Compañía Minera Poderosa S.A., where it was shown that the diameter change in the starter relief drills from 38 mm to 64 mm and the additional use of 8-foot holes for the 2.5 m x 2.7 m section, contributes to being efficient in every shot. In this same instance, it was demonstrated that, optimally applying the mathematical principles used the amount of explosives use can be significantly reduced, reflected in economic savings per shot. The results obtained with the new design are: the power factor went from 1.23 to 1.15 kg/t reducing a 6.8 %, the advance per shot from 1.51 to 2.10 m increasing a 39.2 % and the linear load factor from 23.24 to 21.02 kg/m reducing a 9.6 %; which translates into a monthly savings on the work front of S/. 21,421.12. / Tesis

Thesis (MBA (Business Management))--University of Stellenbosch, 2006. / ENGLISH ABSTRACT: Globalisation and increased communication flow in the world has increased competition tremendously over the last decade. For organisations to stay ahead of their competition it became essential to adapt quickly. Flexible low cost organisations will become leaders in the industry. Collaboration and teamwork in organisations, especially across functions, could maximise flexibility and productivity. Matrix structures were introduced in the sixties by multinational companies and by the early Seventies many other companies followed suit with mixed success. Academic interest faded after the mid Eighties. The challenge of continual, fast growing organisations is opening a debate for project management and cross-functional structures as teamwork and effective collaboration between functional departments become key to success. This study will focus on application of matrix management structures in the new millennium and project management principles applied by a literature search. The best practice model is compiled with specific application to Skorpion Zinc. Skorpion Zinc is a newly commissioned zinc mine and refinery, applying new technology to produce Special High Grade zinc. Application of this model is verified by personnel from the organisation by means of a questionnaire. Research indicates that most project orientated organisations prefer and use matrix management structures to manage their business. Successes and challenges related to crossfunctional structures are similar to those experienced in the Eighties. Implementation and management of the structure is the key to success. Selecting the correct type of matrix structure that will best support the business is vital. The study reveals that the Weak Matrix Management structure applied in the Refinery Department will enhance personnel management, project management and enable optimal utilisation of resources. In addition to the implementation of the structure focus is required in improvement of project management principles. Enabling factors to the Weak Matrix Structure that needs to be encouraged is a cooperative culture, teamwork, open and effective communication. Skorpion Zinc can use their strength of trust within departments and expand this to an interdepartmental trust. It is concluded that the study has identified the latest trends and success factors related to matrix management structures. Best practice suitable to Skorpion Zinc has been identified and verified. By applying this knowledge, the organisation can look forward to producing zinc cost effectively with a contented workforce, thus becoming a world leader in its class. / AFRIKAANSE OPSOMMING: Internasionalisering en toenemende kommunikasie vloei regoor die wereld het kompetisie geweldig laat toeneem oor die laaste dekade. Vir organisasies om kompeterend te bly het dit al belangriker geword om vinnig te kan aanpas by veranderende omstandighede. Aanpasbare, lae koste besighede sal leiers in die industrie word. Spanwerk en samewerking in organisasies, veral tussen funksionele departemente sal lei tot aanpasbaarheid van die maatskappy en produktiwiteit van werknemers. Matriks strukture was in die sestiger jare bekend gestel deur internasionale maatskappye wie se voorbeeld gevolg was deur ander maatskappye in die vroeer sewentiger jare met gemengde sukses. Akademiese belangstelling het gekwyn na die later tagtiger jare. Uitdagings van vinnig groeiende, dinamiese organisasies het opnuut debat rondom projek bestuur en matriks strukture laat opvlam as gevolg van sukses wat bereik word deur samewerking tussen funksionele departemente. Fokus van die literatuur navorsing studie sal val op die jongste toepassing van matriks organisasie strukture en projek bestuur beginsels. 'n Model van beste praktyke van toepassing op Skorpion Zinc is saamgestel. Skorpion Zinc is 'n jong sink myn en raffinadery, onlangs in gebruik gestel, wat nuutste tegnologie aanwend om Spesiale Hoe Graad sink te ontgin en produseer. Werknemers het die toepaslikheid van die model bevestig deur middel van 'n vraelys. Navorsing dui aan dat meeste projek ge-orienteerde organisasies vierkies en wend matriks strukture aan om hul besighede te bestuur. Vandag se suksesse en uitdagings verwant aan matriks strukture is baie eenders as wat ondervind was in die tagtiger jare. Implementering en bestuur van die strukture is die sleutel tot sukses. Die keuse van die matriks struktuur wat die onderneming sal ondersteun is van kardinale belang. Navorsing dui daarop dat die Afgewaterde Matriks struktuur, soos toegepas in die Produksie Afdeling, personeel bestuur, projek bestuur en optimale benutting van menslike hulpbronne sal bevorder. Dit is belangrik dat aandag toegespits word op verbetering van projek bestuur beginsels tesame met implementering van die struktuur. 'n Samewerkende kultuur, spanwerk, effektiewe en op die man af kommunikasie is ondersteunende faktore vir matriks strukture wat bevorder moet word. Die gevolgtrekking kan gemaak word dat die navorsing beste gebruike en sukses faktore van matriks bestuur uitlig. Gebruike van toepassing op Skorpion Zinc is geidentifiseer en bevestig. Deur die kennis toe te pas kan die maatskappy uitsien daarna om 'n wereld leier op sy gebied te word met lae koste sink produksie en 'n bevredigde arbeidsmag.

Recognizing the complexity of coal mining management, e.g., the scarcity of financial resources and the high level of uncertainty, a mixed binary programming model has been developed as an aid for generating production schedules which maximize the associated net present value. Defining the mine layout as a precedence network, with the nodes representing mining blocks, a solution procedure is developed, based on Benders' partitioning scheme. That is, the procedure iterates between two problems, namely, the master (primal) problem, solved by a combination of heuristic and exact methods, and the subproblem (dual problem), solved partly by inspection and partly as a minimal cost network flow problem. The heuristic methods are based on improvements of existing algorithms for scheduling precedence-related jobs on m processors. Computational experiences are presented and the procedure is demonstrated on a mining case. / Ph. D.

La finalidad de este trabajo de investigación es producir cemento geopolímero para la elaboración de shotcrete o concreto lanzado a partir de la activación alcalina de relaves mineros, el cual pueda mejorar sus propiedades físicas y mecánicas, principalmente la resistencia a la compresión. Para llevar a cabo este proceso se utilizarán activadores alcalinos como el silicato de sodio (Na₂SiO₃) e hidróxido de sodio (NaOH). Por otro lado, para la validación de esta investigación se realizará el ensayo normalizado para la determinación de la resistencia a la compresión de concreto en muestras cilíndricas, con el objetivo de analizar las propiedades mecánicas alcanzadas por el shotcrete producido a base de cemento geopolímero de 12 y 15M de concentración de NaOH. Los principales resultados indican que es posible obtener concreto ecoeficiente con una resistencia a la compresión de hasta 19 MPa a los 28 días de curado. Asimismo, es una alternativa sostenible, porque utiliza los relaves y presenta una reducción de un 73% en emisiones de CO2 en comparación con la producción del cemento Portland. En síntesis, este trabajo se centra en desarrollar cemento geopolímero sostenible, el cual se utilizará como material para la elaboración de shotcrete. / The purpose of this research work is to produce geopolymer cement for the manufacture of shotcrete or shotcrete from the alkaline activation of mining tailings, which can improve its physical and mechanical properties, mainly its resistance to compression. To carry out this process, alkaline activators such as sodium silicate (Na₂SiO₃) and sodium hydroxide (NaOH) will be used. On the other hand, for the validation of this research, the standardized test will be carried out to determine the compressive strength of concrete in cylindrical samples, with the aim of analyzing the mechanical properties achieved by the shotcrete produced from 12 and 15M NaOH concentration. The main results indicate that it is possible to obtain eco-efficient concrete with a compressive strength of up to 19 MPa after 28 days of curing. It is also a sustainable alternative, because it uses tailings and presents a 73% reduction in CO2 emissions compared to the production of Portland cement. In summary, this work focuses on developing sustainable geopolymer cement, which will be used as a material to produce shotcrete. / Trabajo de investigación

El presente trabajo de investigación busca implementar una metodología de diseño de mallas de perforación y voladura en la empresa Minera Sotrami S.A, perteneciente al rubro de pequeña minería, con fines de estandarizarlo. La ejecución de dicha investigación se realiza mediante la utilización del algoritmo matemático de Holmberg que permite definir un modelo numérico para el diseño de una malla de perforación, y con la consideración de criterios operacionales encontrar una malla técnica que permita mejorar los rendimientos en las labores de exploración y desarrollo. Para el logro del mismo, se consideró como variable fija el tipo de roca (tipo III A) y las características geomecánicas presentes en ella; el diámetro del taladro de perforación como variable fija; y, el tipo de explosivo y accesorio de voladura como cambiantes, ya que se reemplazó la utilización de guías, mecha de seguridad y dinamita por el empleo de detonadores no eléctricos (Exaneles) y emulsiones encartuchadas. La oportuna y pertinente estandarización del proceso de perforación y voladura permitió obtener los siguientes resultados: el avance por disparo pasó a 1.62 m, el factor de carga se redujo a 13.46 kg/m y el factor de potencia disminuyo considerablemente. / This research work seeks to implement a design methodology for drilling and blasting meshes in the company Minera Sotrami S.A, belonging to the small mining sector, with finality to standardize it. This research is carried out by using the Holmberg mathematical algorithm that allows defining a numerical model for the design of a drilling mesh, and with the consideration of operational criteria, finding a technical mesh that allow improving the performance of exploration and development labors. To achieve it, the type of rock (type III - A) and the geomechanical characteristics present in it were considered as a fixed variable; the diameter of the drill as a fixed variable; the type blasting attachment and explosives as changeable, since the use of guides, safety wick and dynamite was replaced with the use of non electric detonators (Exaneles) and encapsulated emulsions. The opportune and pertinent standardization of the drilling and blasting process allowed obtaining the following results: the advance per shot was to 1.62 m, the load factor was reduced to 13.46 kg/m and the power factor decreased considerably. / Tesis

Business Intelligence (BI) applications are consulted by their users on a daily basis. BI information obtained assist users to make business decisions and allow for a deeper understanding of the business and its driving forces. In a mining environment companies need to derive maximum benefit from BI applications, therefore these applications need to be used optimally. Optimal use depends on various factors including the usability of the product. The documented lack of usability evaluation guidelines provides the rationale for this study. The purpose is to investigate the usability evaluation of BI applications in the context of a coal mining organization. The research is guided by the question: What guidelines should be used to evaluate the usability of BI applications. The research design included the identification of BI usability issues based on the observation of BI users at the coal mining organization. The usability criteria extracted from the usability issues were compared and then merged with general usability criteria from literature to form an initial set of BI usability evaluation criteria. These criteria were used as the basis for a heuristic evaluation of the BI application used at the coal mining organization. The same application was also evaluated using the Software Usability Measurement Inventory (SUMI) standardised questionnaire. The results from the two evaluations were triangulated to provide a refined set of criteria. The main contribution of the study is the heuristic evaluation guidelines for BI applications (based on these criteria). These guidelines are grouped in the following functional areas: visibility, flexibility, cognition, application behaviour, error control and help, affect and BI elements. / Information Science / M.Sc. (Information Systems)

Business Intelligence (BI) applications are consulted by their users on a daily basis. BI information obtained assist users to make business decisions and allow for a deeper understanding of the business and its driving forces. In a mining environment companies need to derive maximum benefit from BI applications, therefore these applications need to be used optimally. Optimal use depends on various factors including the usability of the product. The documented lack of usability evaluation guidelines provides the rationale for this study. The purpose is to investigate the usability evaluation of BI applications in the context of a coal mining organization. The research is guided by the question: What guidelines should be used to evaluate the usability of BI applications. The research design included the identification of BI usability issues based on the observation of BI users at the coal mining organization. The usability criteria extracted from the usability issues were compared and then merged with general usability criteria from literature to form an initial set of BI usability evaluation criteria. These criteria were used as the basis for a heuristic evaluation of the BI application used at the coal mining organization. The same application was also evaluated using the Software Usability Measurement Inventory (SUMI) standardised questionnaire. The results from the two evaluations were triangulated to provide a refined set of criteria. The main contribution of the study is the heuristic evaluation guidelines for BI applications (based on these criteria). These guidelines are grouped in the following functional areas: visibility, flexibility, cognition, application behaviour, error control and help, affect and BI elements. / Information Science / M.Sc. (Information Systems)