Búsqueda de modelos matemáticos para la determinación del espaciamiento óptimo del muestreo sistemático en depósitos minerales tipo Veta
Abstract
Gran parte de los yacimientos minerales que se explotan en el Departamento de Oruro y en el país son vetiformes; vale decir, son estructuras mineralizadas tabulares aproximadamente verticales con una potencia (ancho) muy reducido respecto a las otras dimensiones. Los métodos utilizados para la explotación de estos yacimientos son básicamente dos: Corte y Relleno (cut and fill) y rajos de acopio (Shrinkage). Estos métodos para su aplicación exigen la perforación de galerías horizontales (corridas) separadamente entre 30 m y 40 m; y de excavaciones verticales (chimeneas) separadas también entre 30 m y 40 m. las corridas y chimeneas definen unidades de explotación denominadas "blocks" de explotación. Para la planificación de la explotación del yacimiento es necesario estimar con la mayor confiabilidad posible el contenido promedio (ley media) del mineral de interés de cada uno de los "blocks" de explotación. Para la estimación de la ley media de los "blocks" de explotación se efectúa un muestreo denominado sistemático en las corridas y las chimeneas. El muestreo sistemático se refiere a excavar pequeñas canaletas perpendiculares a la dirección del yacimiento mineralizado tanto en los techos de las corridas como en una de las paredes de las chimeneas. El material obtenido en cada canaleta es embolsado y enviado a un laboratorio de análisis químico para la determinación del contenido mineralógico (ley) del mineral de interés. El muestreo sistemático de un yacimiento mineralizado y el procesamiento de las muestras en un laboratorio de análisis químico forman parte de los costos de explotación de yacimientos; este componente en el costo de explotación puede ser alto o bajo dependiendo fundamentalmente del número de muestras obtenidas. En la actualidad, las canaletas de muestreo tanto en las corridas como en las chimeneas son excavadas cada dos (2) metros, sin tomar en cuenta en absoluto el mineral de interés, el tipo de mineralización, la precisión del muestreo y los costos asociados. La pregunta permanente es ¿Por qué muestras de cada dos (2) metros? El presente proyecto, pretende identificar o en su caso desarrollar modelos matemáticos que permiten definir el espaciamiento óptimo entre muestras para el muestreo sistemático en yacimientos minerales tipo veta. Optimo en el sentido de lograr el mayor conocimiento posible del yacimiento mineralizado al menor costo. El o los modelos matemáticos obtenidos serán aplicados a un caso específico (una veta en algún yacimiento en el que se puedan conseguir datos).
A large part of the mineral deposits that are exploited in the Department of Oruro and in the country are vetiform; that is to say, they are approximately vertical tabular mineralized structures with a power (width) very reduced with respect to the other dimensions. The methods used for the exploitation of these deposits are basically two: Cut and fill and cuttings (Shrinkage). These methods for its application require the perforation of horizontal galleries (runs) separately between 30 m and 40 m; and of vertical excavations (chimneys) also separated between 30 m and 40 m. Runs and chimneys define exploitation units called "blocks" of exploitation. For the planning of the exploitation of the deposit, it is necessary to estimate with the highest possible reliability the average content (average grade) of the mineral of interest of each one of the exploitation blocks. For the estimation of the average grade of the "blocks" of exploitation a systematic sampling is carried out in the runs and chimneys. Systematic sampling refers to excavating small channels perpendicular to the direction of the mineralized deposit both in the ceilings of the runs and in one of the walls of the chimneys. The material obtained in each channel is bagged and sent to a chemical analysis laboratory for the determination of the mineralogical content (law) of the mineral of interest. The systematic sampling of a mineralized deposit and the processing of the samples in a chemical analysis laboratory are part of the costs of exploitation of deposits; this component in the cost of exploitation can be high or low depending mainly on the number of samples obtained. At present, the sampling channels in both runs and chimneys are excavated every two (2) meters, without taking into account at all the mineral of interest, the type of mineralization, the precision of the sampling and the associated costs. The permanent question is Why do you sample every two (2) meters? The present project aims to identify or, where appropriate, develop mathematical models that allow to define the optimal spacing between samples for systematic sampling in vein-type mineral deposits. Optimal in the sense of achieving the greatest possible knowledge of the mineralized deposit at the lowest cost. The mathematical model (s) obtained will be applied to a specific case (a vein in a deposit in which data can be obtained).
A large part of the mineral deposits that are exploited in the Department of Oruro and in the country are vetiform; that is to say, they are approximately vertical tabular mineralized structures with a power (width) very reduced with respect to the other dimensions. The methods used for the exploitation of these deposits are basically two: Cut and fill and cuttings (Shrinkage). These methods for its application require the perforation of horizontal galleries (runs) separately between 30 m and 40 m; and of vertical excavations (chimneys) also separated between 30 m and 40 m. Runs and chimneys define exploitation units called "blocks" of exploitation. For the planning of the exploitation of the deposit, it is necessary to estimate with the highest possible reliability the average content (average grade) of the mineral of interest of each one of the exploitation blocks. For the estimation of the average grade of the "blocks" of exploitation a systematic sampling is carried out in the runs and chimneys. Systematic sampling refers to excavating small channels perpendicular to the direction of the mineralized deposit both in the ceilings of the runs and in one of the walls of the chimneys. The material obtained in each channel is bagged and sent to a chemical analysis laboratory for the determination of the mineralogical content (law) of the mineral of interest. The systematic sampling of a mineralized deposit and the processing of the samples in a chemical analysis laboratory are part of the costs of exploitation of deposits; this component in the cost of exploitation can be high or low depending mainly on the number of samples obtained. At present, the sampling channels in both runs and chimneys are excavated every two (2) meters, without taking into account at all the mineral of interest, the type of mineralization, the precision of the sampling and the associated costs. The permanent question is Why do you sample every two (2) meters? The present project aims to identify or, where appropriate, develop mathematical models that allow to define the optimal spacing between samples for systematic sampling in vein-type mineral deposits. Optimal in the sense of achieving the greatest possible knowledge of the mineralized deposit at the lowest cost. The mathematical model (s) obtained will be applied to a specific case (a vein in a deposit in which data can be obtained).
Description
No. 4