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The accuracy of mineral resource estimation is nowadays one of the most important issues in Geology and Mining industry. The development of automated systems in this field has contributed to improving the quality of the estimation of several types of mineral deposits. There even exist elements with a subjective approach having a direct influence on the precision and accuracy of calculations: one of them is the size of the estimation block. The selection of the size of the estimation block is based mainly on economic and mining criteria. This work presents the influence of the estimation block size on the precision and accuracy of resource estimation using geostastistics estimation and simulation procedures. The procedure is applied to the Mariel deposit of raw materials for cement making. The proposed methodology can be applied to other study cases. [ABSTRACT FROM AUTHOR]

In the corners of podiform bodies of chromites from Merceditas Ore Bodies, located in the Eastern side of Cuba, the continuity and the quantity of information decrease, then the possibility to use the classic methods of geological correlation for underline the ore bodies shape an calculate it volume decrease considerably. For give solution to this problem we use methods that let as to know the probability of occurrence of each rock types in a point or volume in the space and a robust estimation of the error or degree of uncertainness of the estimation of the above mentioned probabilities, that will be used to classified the chromium resources and reserves. Was used ordinary indicator kriging with categorical variables, those categories was defined by tree rock types: peridotites, dunites and chromites. The result was corrected for set the estimation of the tree categories in the interval [0,1] and it sum equal to one. Was created a block model with information of possible proportion that covers each rock type and the grades of the chemistry elements. These last was estimated by the square inverse of the distance in the blocks were the probability of occurrence of the chromites was higher. For determinate the degree of uncertainness relate with the information in existence and the behavior of spatial variability was simulated the rock type by sequential indicator simulation, as criteria of uncertainness we used the standard deviation of the simulations, it was more representative of the uncertainness than the kriging indicator variance. [ABSTRACT FROM AUTHOR]

The Geostatistic Simulation is mainly sustained in the generation values from the variability characteristics of the available information of the studied phenomenon, that is the Non Conditional Simulation. These values are conditioned to experimental data, obtaining one of the possible realizations representative fro the studied reality. The generation of simulations is performed observing a fixed covariance function, having several methods in the stochastic processes. One of the most used methods in the Geostatistic Simulation is presented in this paper: the Turning Bands Method for Three Dimensions. [ABSTRACT FROM AUTHOR]

In this article is exposed an algorithm that allows to diminish, substantially, the number of operations that are usually required to carry out the estimation of the value of a variable, starting from the known values of the same, in a group of points of the space or the plane. The algorithm can be used to accelerate estimation by Kriging, or by the autocorrelation functions method, and permit, therefore, greater speed in the generation of maps and other associated calculations. [ABSTRACT FROM AUTHOR]