Sample size for a crosssectional, cohort, or clinical trial studies kevin m. Sampling and estimation of ore deposits alaska division. Derekoy copper ore reserve is selected to apply uncertainty assessment in npv of ore reserves. Usually but not necessarily, the points of time are equally spaced. Matherons geostatistical method the estimation of ore reserves has been developed to the point at which reallife problems may be handled effectively. The various stages of a geostatistical orereserve estimation procedure are explained, leading to the production of block local reserves and overall global reserves. Kan and zhang 14, 1999 show that the risk premium estimate of a useless factor converges to infinity with probability one as. Resource estimation is used to determine and define the ore tonnage and grade of a geological deposit, from the developed block model. Consistent estimation of crosssectional models in event studies. Developed originally to predict probability distributions of ore grades for mining operations, it is currently applied in diverse disciplines including petroleum geology, hydrogeology, hydrology, meteorology, oceanography, geochemistry, geometallurgy, geography, forestry, environmental control, landscape.
All reserve estimates involve some degree of uncertainty. Ore resource and reserve estimation free download as word doc. Matheron, geoslalislical method or the estimation of ore reserves has been developed to the point al which. Initial mineral resource estimates for the arrowhead and rhodes ridge. Section 4 estimation and reporting of ore reserves. Parlaktuna chapter 2 reserves estimation volumetric calculations the following equation is used in the volumetric calculation of reserves. Example of a drill section through a copper ore body to illustrate ore reserve calculations by the crosssectional method. Geostatistical ore reserve estimation for a rollfront. Cim mineral resource and mineral reserve committee. All basement samples consist of diamond drill core nq, nq2, hq and pq cut with a manual or. Each manual describes in detail all the program capabilities, limita tions, and sample.
The invention provides a threedimensional visual geological exploration reserve estimation method. While cross sectional studies collect data from many subjects at a single point in time, longitudinal studies collect data repeatedly from the same subjects over time, often focusing on a smaller group of individuals that are connected by a common trait. A government of india estimate, shared in the countrys parliament in august 2011, puts the recoverable reserve at 846,477 tonnes. The method is applied to a model of horizontal mergers in section 2, and crosssectional parameters ate estimated in section 3. Consistent estimation of crosssectional models in event. An underground mining method was selected given the deposit geometry and the. Ore reserve estimation and depletion planning for a beach. Ore resource and reserve estimation normal distribution. The simple yet accurate ore reserve estimation technique used are classical methods. The carat is a weight measurement used for diamonds. May 08, 2020 cross sectional vs longitudinal studies. Using gis, 3d model of the studied region, most suitable section planes and grade distributions were obtained and reserve estimation by crosssection method was approached. The mining method is hydraulic mining, which base titanium has used successfully since 2017. The final stage of the whole exercise is the construction of a gradetonnage curve.
Introduction, exploration and geology techniques, ore reserve estimation, feasibility studies and project financing, planning and design of surface mines, mine operations, mine capital and operating costs, management and organization, and case studies. Ore reserve estimation techniques by cross section method. South dune ore reserves estimates is shown in figure 2 below. Sinclair and m vall6e the canadian institute of mining and metallurgy. Cohort and crosssectional statcalc user guide support. Pdf on sep 5, 2003, ben whiting published ore reserve and mineral resource estimation methods current practices and comparisons find, read and cite all the research you need on researchgate. Vb bulk volume of the reservoir rock, bbl ng netgross ratio of formation thickness, fraction porosity, fraction sw water saturation, fraction bo oil formation volume factor, rbblstb stoiip.
This gadir ore reserves calculation is based on the maiden. Table of contentsassay maps and sectionsvolume and tonnage estimatesore volume calculationore tonnage calculationsore grade estimationestimates based on drillhole dataore reserve estimate example 1ore reserve estimate example 2estimates based on underground samplingweighting of assays of individual sampleserratic high assayscomputation of tonnage and grade of ore by. Classical methods employ simple geometric function and rules that are easily applied to simple uncomplicated orebodies. Purchase geostatistical ore reserve estimation 1st edition. A a cross section of boreholes is depicted in white and the intercepts. There are different estimation methods see below used for different scenarios dependent upon the ore boundaries, geological deposit geometry, grade variability and the amount of time and money available. It builds upon a solid base of college algebra and basic concepts in probability and statistics. The uncertainty depends mainly on the amount of reliable geologic and engineering data available at the time of the estimate and. Ore reserve estimation method by using geographic information. Part i contains a comprehensive treatment of the comparative study of the geostatistical ore reserve estimation method over the conventional methods. These methods greatly reduce the uncertainty in reserves. Pdf mineral resources and their subsequent conversion to ore reserves are of key importance to mining companies. Chapter 1 an overview and outline overview j t baldwin, j h lew and m f whitham managing risk in feasibility studies p l mccarthy common sense and good communication effective teambased estimation and classification of mineral resources and ore reserves j vann, p r stephenson, s jackson and g pilger jorc and the canadian.
Geostatistical ore reserve estimation tutorial geologyhub. Methods for ore reserve and mineral resource estimation august 2003. Carrapateena 2019 mineral resources and ore reserves. Types of crosssectional study descriptive a crosssectional study may be purely descriptive and used to assess the frequency and distribution of a particular disease in a defined population. The method comprises the following steps of firstly calculating the attitude direction, the strike and the dip of an ore body, and projecting the ore body on a horizontal plane or a vertical plane. In an effort to obtain information on mineral reserve estimation practices for precious. Pdf geostatistical ore reserve estimation by m david. Ore reserve estimation international nuclear information system. Survey field procedures manual prepared by the division of. The calculation procedure was developed in the following phases. The geostatistical ore reserve estimation method or geostatistics in short is a relatively.
Geostatistics is a branch of statistics focusing on spatial or spatiotemporal datasets. A plan and cross section of the underground mine development of the. This chapter presents definitions of the various factors and criteria used in the production of mine metal, or mineral, inventories and ore reserves. At the end of the study, all possible net present values and their probabilities are given as a probability distribution. Proposed open pits as supported by the ore reserve estimate are presented in figure 2. Another method which also described here is inverse distance weighting idw technique. Plan view 3d, permit boundary area illustrated by green line. Using gis, 3d model of the studied region, most suitable section planes and grade distributions were obtained and reserve estimation by crosssection method.
The study has been marked by a number of changes ed to call it a manual but this was abandoned in. A variety of manual and data checks are in place to check against human error of. As production and pressure data from a field become available, decline analysis and material balance calculations, become the predominant methods of calculating reserves. Sample size for a crosssectional, cohort, or clinical trial. Ore reserves estimation methods will involve sensitivity on open pit shell choice and underground stope size optimization. In the case of gold data, high values are usually cut and the block estimation is performed using truncated grades. Resource estimation additional factors, which are required for the competent person to be confident that there are. The simple yet accurate ore reserve estimation technique used is classical methods. The conventional methods chosen for comparison were. Reserve estimation free download as powerpoint presentation. Conventional methods of resource reserve estimation. Oct 10, 2019 discuss empirical methods of mineral reserve estimation, including sectional methods, polygonal and triangular methods, and inverse distance and contouring methods. Geostatistical ore reserve estimation for a rollfront type.
The iaeas 2005 report estimates indias reasonably assured reserves of thorium at 319,000 tonnes, but mentions recent reports of indias reserves at 650,000 tonnes. Conventional and computer aided ore reserve estimation ijetsr. Cim estimation of mineral resources and mineral reserves best. The following example demonstrates how to calculate a sample size for a cohort or crosssectional study. The stochastic discount factor representation provides a rich set of conditional moment condition based on which estimation and asset pricing tests in principle can be carried out. The techniques used in ore reserve estimation vary from the simple method of polygons through heuristics such as distance weighting methods to quite sophisticated kriging procedures of geostatistics. The discounted cash flow method dcf method, or npv method, based on income approach, is recognized as the fundamental method of mineral assets evaluation, both in international and the russian practice valmin, ivss, methodical guidelines of the state commission on reserves due to its universal. Iron ore mineral resources and ore reserves pdf, 5. Ore reserve estimation methods, models and reality proceedings of the symposium sponsored by the geology division of clm, and held in montreal, quebec, may 1o11, 1986 edited by m. Ore reserve estimation using localized trend analysis. The available drill holes for minable ore reserve estimation numbered 800. The results from the method of polygons are usually inferior to.
Updated kwale south dune mineral resources and ore reserves. Pdf ore reserve and mineral resource estimation methods. Classical methods of ore reserve estimation basic mining. An ore reserve is an estimate of the tonnage and grade that is expected to be delivered to the mill or treatment plant. Pdf errors and uncertainty in mineral resource and ore reserve. Ore reserve estimates and changes in commodity price a.
Reserve classification material type ore mined au gold mined mt gt koz probable rom ore reserve 2. The application will show three different sample size estimates according to three different statistical calculations. Resource and reserve calculation in seamshaped mineral. Introduction in all our statistical work to date, we have been dealing with analyses of timeordered data, or time series. Realistically assumed modifying factors mining, metallurgical, economic, marketing, legal. Jul 01, 1988 mining science and technology, 7 1988 161165 elsevier science publishers b. Alaphia wright department of mining engineering, university of zimbabwe, p.
This type of crosssectional analysis is in contrast to a timeseries regression or longitudinal regression in which the variables are considered to be associated with a sequence of points in time. Geostatistical estimation techniques, such as kriging, block modelling, and. Value and extent of a mineral deposit can be estimated using classical methods or geostatistical methods. Chapter 2 begins with the simple linear regression model, where we explain one vari. Example of a 3d ore deposit block model showing the distribution of low grade blue and. Box mp 167, mount pleasant, harare zimbabwe received february 18, 1988. The results from the method of polygons are usually inferior to those of both the heuristics and geostatistics. But the approach suggested in this paper can be directly applied to the generalized leastsquare gls crosssectional estimation, as well. In this study, a reserve estimation attempt in a silver ore deposit was carried out by the help of geographic information systems gis. Fact sheet mineral resources and reserves estimation. The grade as used cor diamond ore reserve cajculalions can be either the carats per square area normally square metre or the carats per volume of ore normally the cubic metre.
These methods greatly reduce the uncertainty in reserves estimates. The opposite of a cross sectional study is a longitudinal study. Apr 29, 2017 introduction reserves are those quantities of petroleum which are anticipated to be commercially recovered from known accumulations from a given date forward. Pdf ore reserve estimation and strategic mine planning. Descriptions are also provided of the methods available for the production of an overall estimate of grade, tonnage and metalmineral content of a deposit.
Three main groups of ore reserve estimation methods are presently. Estimation practices for reserves of gold deposits springerlink. It is the economically mineable part of a mineral resource. In statistics and econometrics, a crosssectional regression is a type of regression in which the explained and explanatory variables are all associated with the same single period or point in time. Cross section method is another type of conventional estimation techniques in which normally a series of cross sections are constructed to the. The assumed mining method is conventional truck and shovel open. Their reliable estimation is critical to both the confidence in a feasibility study, and. For example a random sample of schools across london may be used to assess the burden or prevalence of asthma among 1214 year olds.
Cross sectional data 23 p art 1 of the text covers regression analysis with cross sectional data. Methods for ore reserve and mineral resource estimation. Crosssectional estimation biases in risk premia and zero. In some ore deposits, the grade distribution is heavytailed and high values make the inference of first and secondorder statistics nonrobust. Pdf handbook of applied advanced geostatistical ore reserve. Geostatics ore reserve estimation of iron ore free download as pdf file. Table of contentsassay maps and sectionsvolume and tonnage estimatesore volume calculationore tonnage calculationsore grade estimationestimates based on drillhole dataore reserve estimate example 1ore reserve estimate example 2estimates based on underground samplingweighting of assays of individual sampleserratic high assayscomputation of tonnage and grade of ore by blocksrevision of. Edumine conventional methods of resource reserve estimation.
Get ore reserve estimation and strategic mine planning. The author in this book describes everything in chapters mainly 1, 3. It was intended as a discussion of various important aspects of reserve estimation that in our view are often neglected in the real world, and for that reason, it does not necessarily follow the normal progression of exploration and deposit development. Matheron, geoslalislical method or the estimation of ore reserves has been developed to the point al which reallife problcllll may be handled effectively. A plan or longitudinal section of the mineral deposit showing exploration. Ore reserve estimation worked example basic mining techniques. Grade g j x0, 66 where fj is an estimate of the average number of stones per.
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