The use of roadheader (RH ) equipment for the underground mining of zinc ores in the San Vicente reservoir is analyzed. The characteristics of the ore bodies of the deposit is described in terms of technical and economic terms for removal by continuous mining system . Compared with the method of room and pillar mining with filling up currently applied , through the present value (PV ) of the cost of the two mining systems determining the continuous mining method has the lowest present value cost . The alternative of continuous mining equipment with RH without the use of explosives to break the rock, compared to the current system of mined with explosives, has other advantages , such as reducing the rocky Massif instability caused by vibrations , surface generation uniform in the excavations , reducing environmental pollution by noise, dust and gases that produce the shots and diesel equi...

Reliable pillar design is of great importance for low cost and safe underground mining support for long periods of time in under ground exploitation.This study analyses pillar variables which have a bearing on underground pillar resistance and stress generation. Two dimensional models were prepared and tested simulating underground mining excavations supported by pillars. Laboratory tests were performedon transparent doubly refracting plates tested in the field of a plane polarized light of a polariscope. On compression the plategenerates fringes of many orders which have values in terms of shear. The level of importance of each variable is obtained bycorrelation and regression analysis of the data. Values of the pillar stress was generated as a function of each of the independentvariables and also as a function of the inter relationships of independent variables and the influence of e...

En yacimientos tabulares inclinados puede establecerse la dirección de profundización óptima, expresada como la ruta del mínimo índice de desencapado, que se traduce como la mínima extracción de estéril y máxima recuperación de mineral. Sea que el yacimiento tenga ley uniforme o variable, hay un punto de inicio de la excavación en superficie y a cualquier profundidad que rinde los mayores ingresos si se elige una dirección óptima de profundización, lo cual puede trazarse conociendo los parámetros geológicos y geométricos del yacimiento y usando conceptos matemáticos fundamentales. Estos límites finales se fijan en secciones verticales geológicos y no requieren la división del yacimiento en bloques. Considerando que cualquier yacimiento mineral tabular irregular o diseminado puede traducirse aproximadamente en un cuerpo tabular regular, el método se aplica a todo yac...

Este estudio presenta una aplicación del método Montecarlo de muestreo estadístico de variables aleatorias que influyen en el comportamiento de un modelo de acarreo minero. Dos variables importantes de ciclo de acarreo son las llegadas de cargas desde los frentes de avance a un punto de transferencia y las salidas de estas cargas desde la estación de transferencia a los botaderos de estéril. Ambas variables se estiman aleatoriamente, utilizando números aleatorios de una distribución de probabilidad. La estimación de estas variables nos permite dimensionar la flota de acarreo y el tamaño de la estación de transferencia analizando tres posibles casos.

The different factors that influence the spacing of levels and chimneys were analyzed. Some of these factors common to all mining operations that influence the spacing of levels are: Characteristics of the mineral and the encasing rock, economic conditions and the possibility of discovering ore in depth. In the case of chimneys, the most influential factors are geological considerations, the mining method and economic aspects. The most important quantifiable specific variables were considered to be the maintenance of chutes between levels and chimneys, the cost of which increases with the time of use and the volume of material that passes through them, that is, the spacing, and also the efficiency and safety translated into incremental cost. with spacing. Combining variables, two graphs were obtained showing the spacing of levels vs. incremental cost per tonne of ore in chute maintenance...

The study minimizes the cycle waiting time of loading and hauling equipment between loading points of the underground mining operation and unloading points on surface. For this purpose the existing loading and hauling system is first analyzed. Present system consists of four underground loading points and 4 unloading spots on surface. The waiting cost is estimated and then the increment in loading points underground is proved for reducing haulage cost which is a bearing component of the mining cost. By applying queuing techniques the possible reduction in waiting cost is obtained by increasing the number of loading points. The information gathered comes from loading and hauling times measured at site. Evaluated variables were number of loading points vs. waiting time cost of haulers and unit cost of underground ore and waste bins.

This study presents a simplified analytical model for ore deposit evaluation for either an orebody in a stage of project or in actual exploitation. Model variables are average ore grades of contained metals, annual rate of ore mined and ore deposit reserves. The model estimates annual net cash income, return on investment and net value of the ore deposit at the investor’s fixed annual interest rate after discounting the total investment. An example of the model application is shown for a copper-zinc ore deposit mined by the open pit method. All three variables of the model are considered to be the most important factors and were chosen from a number of known variables of the annual income flow. The criteria for variables selection follow the 80/20 Pareto rule which shows that 20 percent of the factors account for 80 percent of the results. The surface mining method was chosen by compar...

The anchor bolt or tendon is an effective, simple and quick installation and lower cost support device than any of the known support methods. There is a wide variety of bolts and tendons to fix the rock, ranging from wooden bolts to iron pipe bolts and smooth and corrugated steel rods with anchors that are generally of two kinds: point and longitudinal. The most widespread at present is the longitudinal anchor, of which the cement grout anchor is used more for its ease of application and low cost. The cement grout, however, has deficiencies for its application in anchorage due to its low resistance to tension and shear, volumetric contraction when setting, low adherence capacity, long setting period, low resistance to corrosion, humidity , to weathering and vibrations. The alternative is resin, but its high cost has practically eliminated its use as an anchor for bolts and tendons, espec...

The feasibility of co-disposal of tailing and clearance is been evaluated in Yauricocha Mine, for which one it is been studied the involved variables such as cut and compression resistance, permeability, density, particle size, chemical composition for tailing and clearance of the mine, leaching facility of minerals in both, influence of seismic acceleration in the stability of tailing and clearance’s slopes. It was found that the most stable mixture from a physical and chemical point of view is three of clearance to one of tailing (3C/1T). The safety factor calculated by the Bishop algorithm SLIDE, is above 1.1 in pseudo-static conditions. In addition, there were evaluated more forms of joint storage for clearance-tailing, concluding that for the Yauricocha conditions, it can be used injections of thickened tailings through perforated pipes placed in the advancing front of the landfil...

The productivity of a rock charger operates on a front surface mining is influenced by many variables. We identified those considered most important and for a type charger model number measurements were taken in the field. Using linear regression expressions that allow predicting the dependent variable as a function of the independent variables were deducted. The dependent variables were identified : production tonnage , fill factor , and delay characteristics of the excavation. The independent variables were : bench height , boot size and fragmentation. Least squares system is used to predict the performance and cost given certain values ​​of the remaining variables in the regression equation but there is the problem of selecting the dependent variable. Two or more variables in the system might seem equally dependent , since the process to test significance of the variable can be if...

On-site mining is a poorly understood technique for recovering minerals and metal elements from mineral deposits. It comprises methods of dissolving in water and leaching using aqueous chemical compounds that are injected into mineral deposits. There are a large number of minerals that can be recovered by these two methods: By dissolution taking advantage of the solubility in water and the massive form of geological occurrence; by leaching on site using chemical solutions similar to surface leaching. By leaching in situ, metals can be recovered from mineral deposits in which conventional methods of mechanized mining are not applicable due to their low grade, depth of location, dissemination and which have a high degree of natural permeability or artificially created by techniques such as hydrofracturing of the Deposit. In the past it was successfully applied in uranium mineral deposits a...

Through probabilistic analysis may prove the truth or falsity of a hypothesis. The application of the 3 basic laws of probability theory can prove the certainty of the location of points of a network of triangulation surveying several adjacent mining concessions whose location accuracy was questioned by one of the parties. The names of the vertices of the triangles are true and were taken to demonstrate the method.

Drilling and blasting is generally used for fragmenting hard in situ rock in mine excavation. This method however, in addition of being expensive, it causes environmental pollution by noice, dust, vibrations and gases. It may also generate social conflicts with native communities around the mining operation as it disturbs and alters the inhabitants safety and health. Consequently, it is important to develop non drilling and blasting rock breackage methods. This can be achieved by both appropriate usage of continuous mining systems in hard rock and ingenious use of the rock tensile resistance which is ten to thirty times lower than its compressive strength. Most of the current drilling systems make use of the compressive resistance to drill and blast rock with explosives. There is no domestic experience of hard rock mining with continuos miners. The unique continuous miner adquired by an ...

In situ metalic mining are sistems of metal elements recovery through leaching at their primary emplacements in hard rock ore deposits by appropriate chemical solutions. The methods involve recuperation of metals from ore bodies by circulating solutions through the ore in its undisturbed geologic state and recovering these solutions for processing. In order to attain acceptable orebody permeability for flowing of leach solutions, fragmentation is a basic variable. It should be obtained by drilling and blasting with explosives or by hydrofracturing. Examples are some Southern USA in situ mining operations where rock fragmentation with explosives was succesfully tried in coyote holes or open pit blasting grids. Other significant in situ mining variables are the mineral geologic genesis which works in opposite direction to the insitu leach treatment, the natural rock porosity, the ore left ...

Accesible and non accesible underground fires in metal mines may be generated but they are not so frequent as in coal mines. However, metal mine fires generally develop more extensively causing greater losses but with few deaths as compared with coal mine fires. There are many causes of fires in mining operations but those fires in unstable pyrites are more dangenous because of the rapid fine graned sulphyde oxidation in contac with oxigen in air or water. Fires in underground mines may be controlled by flooding of the affected area, suffocation and filling of the area by mud or tailings, this last being the efective way of fire fighting particularly in fires of large extension. Effective ways of fire prevention consist of preventing subsidence of the mined area by appropriate election of the mining method, no use of inflammable materials either as excavation support or insulating barrie...

The Sub drilling length in surface mining production drilling grids, can be reduced or eliminated by addition of air chambers at the bottom of drill holes in blasting rounds. Sub drilling removal means surface mine operations revenue increase due to lower drilling and blasting costs, seismic vibrations decrease at inside and outside excavation areas, stable berms and slopes, productivity increase of drilling, loading, excavation, haulage and primary crushing equipment due to better ore fragmentation. The method was satisfactorily tested in a medium hardness rock at a quarry operation.

Mine equipment selection is a complex task due to numerous technical, geometrical and economical variables involved. The variety of equipment manufacturers and agents carrying different models, types and sizes make the selection procedure even more complex. The mine planner does not have a tool to correctly select the equipment or fl eet for a project. Simulation fi lls the gap and contributes to this goal. This study tries to apply deterministic and probabilistic simulation approaches in selecting mining equipment using fi eld data from two surface mine operations. The deterministic model uses a one year production plan from a quarry. The equipment fl eet is selected on the basis of minimum unit cost for both drilling and excavation-haulage equipment fl eets. For the probabilistic approach the GPSS language is applied. Programs were prepared for various combinations of loaders and haule...

The Antilla ore body open pit mining equipment is estimated for a total movement of 544 million metric tons of ore and waste in 20 years of active operation. Mining equipment is evaluated from the point of view of 3 working systems and time savings on the performance system. Three working alternatives are analyzed: Alternative 1 consists of three-8 hour shifts per day, six day per week operation. Alternative 2 includes three-8 hour shifts per day, 7 day per week and alternative 3 consists of four-six hour shifts per day 7 day per week work. Equipment size is chosen as a function of daily production, pit geometry, bench height, working angle and space requirements for safe operation of each equipment. Performance parameters used in equipment estimation were taken from 3 similar mining operations. Lost time analysis on the equipment performance were also considered in order to improve util...

The GPSS/H (General Purpose Simulation system), is both a computer programming language and a discrete random simulation system. It is versatile, easy to write and can solve a wide range of problems many of them concerned with the mining industry. This language is non procedural designed for a special purpose which tries to anticipate what the programer is doing. Programs are of short computational code and similar to the problem being solved. The application example shows that for an 8 truck fleet hauling ore and waste from 4 hydraulically operated underground bins onto two unloading points at surface for ore and waste, it is required to add one additional bin to avoid queues and attain minimum operating cost.

La fragmentación de roca dura in situ en una operación minera, generalmente se efectúa por perforación y voladura. Pero este método además de ser costoso, origina polución del medio ambiente por ruido, polvo, vibraciones, gases y hasta conflictos con las comunidades cercanas a la operación minera porque perturba la tranquilidad y seguridad de los pobladores. Urgen, por lo tanto, métodos de fragmentar la roca sin perforación y voladura. Esto puede lograrse con el conocimiento apropiado de los métodos de minado continuo en roca dura y con el eficiente aprovechamiento de la resistencia a la tensión de la roca que es del orden de 10 a 30 veces menor que la resistencia a la compresión. La mayoría de los equipos de perforación actuales hacen uso de la resistencia a la compresión de la roca para perforar y usar explosivos para fragmentar roca. No hay experiencia en el uso de min...