Though the results thus obtained may not represent the true average value of the deposit, it is on these results that estimates of practically all large orebodies are. Jan 01, 1977 a f t e r williamson and mueller 1 9 7 6. Selection and gradetonnage relationships springerlink. Geostatistical simulations for orebodies can be used to obtain grade tonnage curves, and determine uncertainty and risk assessments. Computeraided cutoff grade optimisation for open pit mines. The tonnagegrade curve can be considered the thumbprint for the deposit. In this paper, the computational principles of the fuzzy tonnage average grade curve and a case study. Forecasting the grade tonnage curves and their uncertainty at the mehdiabad deposityazd, central iran. If the exploration of a possible deposit is well advanced, one can work with geostatistical methods, which take the spatial interdependence of drill hole data into account see e. Grade tonnage cutoff curve representation of escalones copper deposit, showing actual values. Dec 14, 2012 figure 5 grade tonnage tables and graphs for indicated and inferred resources this shows conceptual grade tonnage relationships only and is derived from inferred and indicated resources for which economic viability of realising tonnage above any given grade cutoff has not been assessed at this time. The distributions and relationships of grade and tonnage among.
Sedimenthosted gold deposits of the worlddatabase and. Figure 1 grade tonnage curve for the niobium mineral. At a more detailed level of investigation, mine design software can. Many exploration projects have a chequered history with many owners. Both tonnage and grade of sulfide deposits associated with komatiitic rocks follow lognormal distributions. A cumulative metal tonnage curve is constructed to display the simulation results. The grade tonnage curve for the oxidised zone is shown in figure 2 below.
These are unusual concentrations of gold, mercury, and chromium, but researchers question whether they are unique. Metallurgical contentore reserve calculationsmineral ore reserve case 1mineral ore reserve case 2mineral ore reserve case 3 the usual method of sampling mineral deposits is to drill holes and assay the sludge or core. The only requirement is that the logarithmic variance of the small b l o c k s w e can select at mining be k n o w n t o be equal t o 0. In practice, blocks are selected according to their estimated value and not according to their true unknown value. A mineral deposit includes tonnages with different grades and other attributes positioned according to a. Appendix a gives the summary statistics for the new grade tonnage models and appendix b displays the country codes used in the database. Though the results thus obtained may not represent the true average value of the deposit, it is on these results that estimates of practically all large orebodies are made. Curve resistance curve resistance is an estimate of the added resistance a locomotive or car must. Tonnagecutoff model and average gradecutoff model for a. Volcanogenic massive sulfide deposits of the world. For the deposits in this file, the following spatial rule was used to determine which ore deposits were combined. The length of vertical curve l is the projection of the curve onto a horizontal surface and as such corresponds to plan. View academics in grade tonnage curves on academia. Understanding cutoff grade 4 tonnage, grade, and costs or.
Other cruder methods have to be applied to arrive at approximate estimates of grade and tonnage or potential grade and tonnage. Vancouver, british columbia, may 19, 2020 globe newswire k92 mining inc. Waveformpac provides a comparison of actual tonnage waveform to press capacity curve user to input up to 15. The basic principle of this design is the creation of curved shapes from the intersection of straight lines. Luc is application of uc, where the uc results are presented as a localised grade model rather than as a grade tonnage curve representing a large volume. In order to avoid serious errors in calculating a grade tonnage curve, we must be able to define clearly the relationships existing between estimates and the corresponding true values. Sedimenthosted gold deposits of the worlddatabase and grade. Sillitoe 1995 examined the history of 53 circumpacific producing baseand precious metal mines. Calculations ofgradeandtonnage fortwo coproducts from.
Mineral resource classification is the classification of mineral resources based on an increasing level of geological knowledge and confidence. Calculations of grade and tonnage for two coproducts from a projected south african gold mine by e. Its purpose is to show how to correctly set a gradetonnage problem. In the mining industry, from the geology and mine planning areas to management, the grade tonnage curve has been applied in economic and financial analysis probably being one of the most important tools used in determining the volume and grade of material in face of variations of the cutoff grade. In an effort to achieve a standard set the classifications, representative bodies from australia, canada, south africa, the usa and the uk reached a provisional agreement in 1997 on the definitions of each of the various mineral classifications. For every ton of train weight in a grade, 20 pounds of tractive effort is needed for each 1% of slope. A monte carlo simulation model that uses the tonnage grade relationship for the porphyry copper deposits is used to construct metal distribution scenarios. Jul 19, 2011 the risk quantification in grade tonnage curves is critical for capital investment in mining projects.
Provide a name for the grade tonnage graph in the windows toolbar. Its purpose is to show how to correctly set a grade tonnage problem. The tonnage grade curve provides two key characteristics for the deposit under investigation. The grade tonnage curve under the model validation compares the block model grade tonnage curve with the expected theoretical grade tonnage curve for that support in other words the block size that has been read directly from the loaded block model. Dynamic visualisation of single or multiple planes through advanced reserve reporting with ability to break down by support for a large number of blocks with options to add, delete or modify variables in real time. The process of grade and tonnage curve construction involves the following steps. Design grade for railways ideal maximum for railway grade. Forecasting the gradetonnage curves and their uncertainty. Figure 1 grade tonnage curve for the niobium mineral resource estimate mrima hill deposit figure 2 surface plan view of resource model showing continuity of high grade zone grade nb205 06 tonnage curve mrima orebody inferred. Finally, the fields of the data file are explained. You can click the add button under curves to add more grade tonnage curves to the graph. A common variation of grading on a curve is to use a variety of different methods to adjust the test grade in some way.
Pdf significance of the cut offaverage gradetonnage. Cutoff grade determination for the maximum value of a small. Grade tonnage curves and change of support youtube. Therefore, the metal tonnage cutoff curve and tonnage average grade curve are achieved, as shown in fig.
A range of cut offs can be defined by entering a starting and ending value and the step change. The new grade tonnage curve features include optional configurations for mass and grade as well as a report data table which summarizes the quantities in the. The oxidised zone displays the following grade tonnage relationship. The traditional grade tonnage curve represents an optimistic scenario since it considers that all tonnage above one cutoff is available to be mined. Grading on a curve and how it affects students through. Forecasting grade tonnage curves at the mehdiabad deposit boll.
A 1% grade is defined as a vertical increase of one foot for each 100 feet of horizontal distance. Figure 5 grade tonnage tables and graphs for indicated and inferred resources this shows conceptual grade tonnage relationships only and is derived from inferred and indicated resources for which economic viability of realising tonnage above any given grade cutoff has not been assessed at this time. Starting from the definition of ore and ore reserves, the different parameters influencing the. The maf approach proves itself to be an efficient method for joint simulation. You will be asked to provide a file name and storage location for the new pdf file. Grade nb205 06 tonnage curve mrima orebody inferred resources no cutoff applied cutoff. Locomotive power calculations greenville, south carolina. The grade and tonnage model of mineral deposits cox and singer, 1986. Dynamic visualisation of single or multiple planes through advanced reserve reporting with ability to break down by support for a large number of blocks with. What is the optimal and sustainable lifetime of a mine.
The important features tokeepinmind arethat themarginal distributionsandthecorrelation coefficient areapplicable toore blockvalues that areconsidered tobeofanappropriate sizeforselective mining. Cutoff grade determination for the maximum value of a. The grade tonnage curve is usually calculated with the insitu resources or reserves and shows. In the mining industry, from the geology and mine planning areas to management, the grade tonnage curve has been applied in economic and financial analysis. A given locomotive, then, can haul only half the tonnage up a.
Grading on a curve means that you as a student and your grade in an exam is relative to the grades of your classmates. Grade and tonnage data are available to varying degrees for districts, deposits, and mines. Figure 47 schematic grade tonnage curve for scarce elements. Improvements in grade tonnage curve prediction via. Grade and tonnage curves grade and tonnage curves graphically describe the distribution of tonnage and average deposit grades.
Either geologically or politically defined regions may be used depending on the reasons for the analysis. In these notes we will mainly be concerned with plane curves n 2 and space curves n 3, but in order to treat both cases simultaneously it is convenient not to specify n. All mineralized rock within 500 meters was combined into one deposit. While its not required for all teachers to practice curving on a grade, plenty of teachers in all types of formal education do this when they think its necessary to help more students pass. Thus, as knowledge of a deposit improves, so does the gradetonnage curve. Pdf the sensitivity analysis applied to the grade tonnage relationship in mining. When a teacher grades on a curve, they adjust their class scores accordingly. Gradetonnage curves, orewaste selection and planning problems. In order to avoid serious errors in calculating a grade tonnage curve, we must be able to define clearly the relationships existing between estimates and the. Fuzzy tonnageaverage grade model based on extension. Pdf first estimates of grade and tonnages and potential. Grade tonnage curve tujuh bukit oxide resource 2012 0.
Grade tonnage curves to compare the estimates produced from the face sampling with the actual values in the stopes we have constructed grade tonnage. Wintriss smartpac systems equipped with the advanced waveformpac load monitor can help you determine if your work is within the rated capacity of the machine. Gold grade and tonnage models of the gold deposits, china. A section of highway has vertical and horizontal curves with the same design speed. Forecasting the gradetonnage curves and their uncertainty at. The cutoff grade g can now be calculated from the equation. Gradetonnage curves, orewaste selection and planning. A parametrized continuous curve, for which the map i rn is dif. Usually the grade tonnage curve is not calculated with mineable reserves which depends on the mining method. The basic curve design is achieved by connecting equally spaced points that are placed on. Pvi is the point of intersection of the two adjacent grade lines. Gt gold files technical report for saddle north project. Feb 17, 2018 the tonnage grade curve provides two key characteristics for the deposit under investigation. For each percent of ascending grade, there is an additional resistance to constantspeed movement of 20 lbs.
Forecasting the gradetonnage curves and their uncertainty at the. Pdf significance of the cut offaverage gradetonnage sensitivity. This extrapolation is misleading, however, for both statistical and geological reasons. Block tonnage was estimated from volumes using an average density per lithological unit. Simple horizontal curves types of curve points by studying tm 5232, the surveyor learns to locate points using angles and distances. Figure 1 grade tonnage curve for the niobium mineral resource estimate mrima hill deposit figure 2 surface plan view of resource model showing continuity of high grade zone. The intention of this project is to describe uc and luc in an understandable manner, discuss approaches for how to. Volcanogenic massive sulfide deposits of the worlddatabase.
Grade tonnage curves and change of support snowden. The grade tonnage curves for each realisation are plotted and compared with the generated one by the kriging estimate. Revisiting the cumulative gradetonnage relationship. Kntnf is pleased to announce results from the updated resource estimate that has been completed on the kora deposit, at its producing kainantu gold mine in papua new guinea. If a horizontal curve on this highway is on a twolane section with 12ft lanes, has a central. Predicted grade tonnage curve allows you to quickly generate grade tonnage curves at any given block size without the need to import a block model. Rather than using the minimum lengths of curve calculated, consideration should be given to increasing the curve lengths to provide additional sight distance and reducing the length of the 5 percent grade. Grading on a curve austin community college district. Most of the time, this type of grading boosts the students grade by moving his or her actual percentage up a few notches or boosting the letter grade. The model usedforthegrade tonnage calculation for oreabove ajoint pay limit isthe bivariate lognormal model asoutlined in fig. This compares with a resistance on level, straight track of about 5 lbs.
A notable change is in the reporting of silver in more than 10 percent of deposits. Grade tonnage curve for underground resource at nsr cutoffs 0. Plot the data are plotted as quantilequantile plots plot. Any curvature on the maximum grade is assumed to be grade compensated, as. Grade tonnage curve for open pit resource at nsr cutoffs figure 2. Extrapolation on the basis of the negative grade tonnage correlation shown for the mixed population seems to imply the occurrence of large tonnage very low grade deposits, which could be important in supplying future copper needs. Summary statistics of grade tonnage models for nevada logarithms base 10 except fe, which is percent. It is an unconstrained grade tonnage curve which, although very common, it is based in an assumption that can hardly be considered realistic especially in underground mining methods. Applying these in multielement deposits can be a difficult practice, as the related attributes using the traditional cosimulation approaches require intensive. Horsepower to trailing tonnage ratio for different types of trains general merchandise or manifest freight train low horsepower. Jul 24, 2018 the grade tonnage curve for the fresh zone is shown in figure 3 below. One percent of a ton or 2000 pounds equals 20 pounds. A resource analysis based on porphyry copper deposits and.
Firstly, the blue line represents the cumulative tonnage y1axis of all blocks with grade at or. Understanding cutoff grade 4 tonnage, grade, and costs. For the fresh zone the following relationship is seen from the grade tonnage curve. This new grade and tonnage model is remarkable in that the estimated parameters of the resulting grade and tonnage distributions are comparable to the previous model of mosier and others 1992. Grade tonnage cutoff curve representation of escalones copper deposit. Creation of customised reports including grade tonnage curves. Grade and tonnage relationships among copper deposits. At a cutoff grade of 2% tgc the deposit will have a balance of 20. Risk quantification in gradetonnage curves and resource. This early idea about grades and tonnages we will call grade potential and tonnage potential. The export button in the windows toolbar saves the current grade tonnage graph as a pdf file. A grade tonnage curve combines two or three equations together to produce one of the more important tools for analysing the data indicating the potential.
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