共查询到20条相似文献，搜索用时 683 毫秒
1.
目前,在我国使用双指标体系圈定矿体,即用边界品位与最低工业品位两项品位指标圈定矿体。在用双指标法圈定矿体时,矿床或矿体中不可避免含有部分矿块品位介于边界品位与工业品位之间的资源储量。在我国矿山露天开采、地下-露天联合开采中,边际品位最优化的经济 相似文献
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金矿床品位—储量数学模型的建立及应用 总被引：2，自引：0，他引：2
本文通过研究云南某金矿床的品位分布规律，建立了该矿床三参数对数正态分布的数学模型，即边界品位－储量数学模型，并首次提出“工业 矿体含矿率”的概念，以此作为划分表内矿和表外矿界线的标准；建立了块段最低工业品位－表内矿石储量的数学模型。最后运用这两个数学模型对不同品位指标方案进行了储量计算，经验证该模型可行，计算结果可信。 相似文献
3.
再论双品位指标圈矿与尚难利用(表外)储量 总被引：1，自引：0，他引：1
通过对工业品位应用和产生条件的分析,揭示了单工程或块段最低工业品位（ 文中简称工业品位）并非圈矿指标和储量分类的标准。提出了在技术条件允许的前提下,普查阶段的矿床最低工业品位是勘查各阶段划分储量类别的标准,质量介于边界品位与单工程或块段最低工业品位之间的、不能成为独立开发对象的储量部分属于表内储量。在现行储量计算方法下,边界品位是合理的圈矿用品位指标 相似文献
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试论市场经济条件下圈定矿体的4项品位指标 总被引：10，自引：0，他引：10
阐述了在我国市场经济条件下，圈定矿体和划分不同储量／资源量的方法。提出了圈定矿体的4项品位指标的概念和确定方法。这4项品位指标依次为边界品位、边际品位、经济品位和矿床平均品位。利用前3项品位指标可以分别圈定矿体边界、次边际的资源量、边际经济的储量、经济储量。利用矿床平均品位可以衡量矿床是否具有投资价值。 相似文献
5.
本文通过研究云南某金矿床的品位分布规律,建立了该矿床三参数对数正态分布的数学模型,即边界品位-储量数学模型,并首次提出“工业矿体含矿率”的概念,以此作为划分表内矿和表外矿界线的标准;建立了块段最低工业品位-表内矿石储量的数学模型,最后运用这两个数学模型对不同品位指标方案进行了储量计算,经验证该模型可行,计算结果可信。 相似文献
6.
指出，目前我国推行的矿产工业指标中，无论对矿化不均匀还是较均匀的矿床执行三项品位指标，均有利于正确评价矿床的工业价值。认为，矿床最低工业品位虽不是一项圈定矿体、计算储量的直接指标，但却是决定矿床能否被工业利用的关键品位。建议，以矿床最低工业品位为界，在能利用储量（表内储量）一类中划分出应盈利的能利用储量（应盈利的表内储量）和尚难盈利的能利用储量（尚难盈利的表内储量）两个亚类。 相似文献
7.
矿石的工业品位是重要的矿石工业指标,随着国家经济政策、科学技术的进步、矿床地质条件及矿石需求程度而变化。开展矿产资源综合评价及综合利用,不仅可以降低圈定矿体的矿石工业品位,增加矿产资源储量,而且可以综合回收共伴生矿产资源,从而提高资源利用的经济效益、社会效益和环境效益。文章以甘肃省白崖沟金矿为实例,说明了综合指标在该矿矿体圈定、资源量估算中的应用情况。该矿床中主要有用组分为Au,共生矿产为Ag,且与Au为同体共生矿产,但矿床中Au、Ag单独均达不到工业品位一般要求。为综合利用矿产资源,采用Ag对Au 0.016的折算系数,制定了(Au品位+0.016×Ag品位)的综合品位Ⅰ方案:边界品位0.5 g/t、工业品位1.5g/t和Ⅱ方案:边界品位1 g/t、工业品位2 g/t两套方案,经论证,从资源利用率、开采技术条件、经济效益等方面比较,确定Ⅱ方案较优。采用Ⅱ方案的综合指标对白崖沟金矿进行矿体圈定连接,比利用一般工业指标估算的资源量大幅增加,金矿工业矿石量增加3.5倍、金属量增加1.7倍,符合矿产资源综合勘查评价规范的要求,达到了充分利用矿产资源、增加经济效益的效果。 相似文献
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10.
张清 《有色金属矿产与勘查》1997,6(2):110-112
铜坑矿床由细脉状矿体组成，据市场价格将锡、铅、锌品位换算成对就原锡当量品位，并据生产系统经济分析所得的品位盈亏点，重新确定锡当量边界品位为０．８５％，据总体矿化趋势圈定出几个富矿体开采，其间的贫带，夹石留作矿柱，大幅度降低了成本，提高了效益。 相似文献
11.
Ali Parhizkar Mohamad Ataei Parviz Moarefvand Vamegh Rasouli 《Arabian Journal of Geosciences》2012,5(6):1279-1288
Many of the open-pit mines suffer from the lack of reconciliation between estimated and actual grades. In a mining operation, grade reconciliation is the comparison between the values of the estimated grade calculated in exploration stage and the actual grade obtained from more reliable data such as blast holes?? samples. Many different factors affect the degree of reconciliation in a mining operation. In this paper, the factors related to estimated grade which affect the reconciliation process in the exploration stage of the orebody are investigated. These factors constitute the sources of uncertainty for the upcoming phases of the mining life. Among these parameters, the inherent variability, statistical uncertainty, and systematic uncertainty are the most important factors. In this work, these parameters are studied in further detail, and, accordingly, for each of these uncertainties, a correction factor is determined in the proposed model. The model was applied to the study of real data taken from an iron open-pit mine in Iran. The results of the case study indicated that the systematic uncertainty, inherent variability, and statistical uncertainty are, in order, the main sources of uncertainty on grade reconciliation process. Applying the correction factors to estimated grade values has increased the amount of grade reconciliation from 10%, at original condition, to 50%, at new condition, in the case study. 相似文献
12.
Roland Froidevaux 《Mathematical Geology》1984,16(4):327-350
One of the tasks routinely carried out by geostatisticians is the evaluation of global mining reserves corresponding to a given cutoff grade and size of selective mining units. A long with these recovery figures, the geostatistician generally provides an assessment of the global estimation variance, which represents the precision of the overall average grade estimate, when no cutoff is applied. Such a global estimation variance is of limited interest for evaluating mining projects; what is required is the reliability of the estimate of recovered reserves or, in other words, the conditional estimation variance. Unfortunately, classical linear geostatistical methods fail to provide an easy way to estimate this variance. Through the use of simulated deposits (representing various types of regionalization)the present paper reviews and discusses the effects of changes in cutoff grade and selective mining unit size on the conditional estimation variance. It is shown that, when the cutoff grade is applied to a pointsupport (sample-size)distribution, the conditional estimation variance appears to be readily accessible by classical formulas, once the conditional semivariogram is known. However, the evaluation of the conditional estimation variance seems to be less straightforward for the general case when a cutoff is applied to the average grade distribution of selective mining units. Empirical approximation formulas for the conditional estimation variance are tentatively proposed, and their performance in the case of the simulated deposits is shown. The limitations of these approximations are discussed, and possible ways of formalizing the problem suggested. 相似文献
13.
Forecasting of recoverable reserves aims to predict the tonnages and grades that will be recovered at the time of mining. The main concern in this forecasting is the imprecision in the selection of ore/waste resulting from both the so-called information effect or information that becomes available during grade control, and the support effect or mining selectivity during mining. Existing approaches to recoverable reserve estimation account for mining selectivity; however, they largely ignore the information effects from future data becoming available through grade control practices. An application at the Morila gold deposit, Mali, is utilized in this paper to document a new simulation-based approach for recoverable reserve forecasting that incorporates the potential effects of future grade control data. This accounts for the information effect as well as changes in data quantity and quality over time. In addition, the case study at the Morila mine elucidates the use of a newer, very efficient, and practical alternative to traditional simulation techniques. This direct block simulation method forecasts recoverable reserves directly into the selective mining unit (support) size under consideration. The case study demonstrates the practical uncertainty assessment of the recoverable reserves within the deposit, so that expected inaccuracies in the selection of ore /waste can be accounted for. This allows for fully informed mining decisions to be made that incorporate the effects of information and selectivity while quantifying the potential impact of uncertainty on the mine operation and its final economic outcome. 相似文献
14.
Improvements in Grade Tonnage Curve Prediction via Sequential Gaussian Fractal Simulation 总被引：1，自引：0，他引：1
An application of sequential Gaussian fractal conditional simulation is presented, using actual sparse, irregularly spaced open cut gold data, to predict the grade tonnage curve associated with a single mining bench. It is shown that this constitutes an improvement over the prediction of the grade tonnage curves obtained via standard sequential Gaussian simulation and median indicator simulation. The fractal conditional simulation method uses the model of the covariance of increments of fractional Brownian motion together with the fractal co-dimension derived from a truncated power semivariogram model to create conditional simulations from irregularly spaced data. The grades and tonnages above several discrete cut offs are calculated for each of one hundred simulations, and the mean and variance of the grade and tonnage values for each cut off are computed to give an average grade tonnage curve with associated confidence limits. 相似文献
15.
Andrew Richmond 《Mathematical Geology》2003,35(2):195-215
Traditional mining selection methods focus on local estimates or loss functions that do not take into account the potential diversification benefits of financial risk that is unique to each location. A constrained efficient set model with a downside risk function is formulated as a solution. Estimates of this nonlinear mixed-integer combinatorial optimization problem are provided by a simulated annealing heuristic. A utility framework that is congruent with the proposed efficiency model is then used to choose the optimal set of local mining selections for a decision-maker with specific risk-averse characteristics. The methodology is demonstrated in a grade control environment. The results show that downside financial risk can be reduced by around 33% while the expected payoff is only reduced by 1% when compared to ore selections generated by traditional cut-off grade techniques. 相似文献
16.
地下与露天复合采动影响下边坡岩体稳定性评价方法的研究 总被引：15，自引：3，他引：12
矿产资源的开采, 有些是按地下与露天复合开采方式进行。依据采区的空间对应关系, 两种采动影响域中的一部分相互重叠, 导致采动效应相互作用和相互叠加, 从而组成一个复合动态系统, 因此边坡岩体变形机理更加复杂, 与单一露天开采相比有较大的差异;然而, 过去在处理此类问题时近似地应用单一露天采动影响下的分析方法, 结果与实际情况存在一定差异;本文在理论分析的基础上, 推导出边坡稳定性的评价方法, 为此类矿山后续采矿设计及安全生产提供科学依据。 相似文献
17.
Since 1998, BHP Billiton has mined diamonds at the Ekati Diamond Mine™ near Lac de Gras in the Northwest Territories of Canada. Current operations are based on mining multiple pipes by the open-pit method, but as some pits deepen, converting to underground mining is being considered.
As a test of underground mining methods and to provide access to the lower elevations of the Panda and Koala pipes, the Koala North pipe is being developed for underground mining. Initially, the top 40 m of the pipe were mined as an open pit to provide grade information and a prepared surface for the transition to underground mining. Currently, Koala North is being developed as an open-benching, mechanized, trackless operation. Although the method was successfully used at several De Beers diamond operations in South Africa, it has never been tested in an Arctic environment.
This case study describes basic geology, mining method layout and ongoing geological and geotechnical investigation. From the beginning of underground development, geotechnical daily routines have been fully integrated within the technical services department, which supports the operation. Geotechnical, geological and structural information obtained from underground mapping and core logging is compiled, processed, reviewed and analyzed on site by the geotechnical staff. Conclusions and recommendations are implemented as part of the operations in a timely manner. This ongoing “live” process enables the operators to make the most efficient use of resources both for ground support and excavations as well as to address safety issues, which are the top priority. 相似文献
18.
In open pit mining, cutoff grade is one of the most important factors in production planning, which is simply defined as a grade that discriminates between ore and waste. It is also a sensitive parameter can have a major impact on the net present value and cash flow of the projects. On the other hand, dilution is one of the most important and sensitive parameters in the mining projects, which is closely related to the cutoff grade. Choosing the optimum cutoff grade is of considerable importance, since it has a significant impact on the mining operations. One of the most popular algorithms for determination of the optimum cutoff grade is the Lane’s algorithm. But in the Lane’s algorithm, mining dilution and its cost is not considered during the cutoff grade optimization. In this paper, effects of dilution on the cutoff grade are studied using Lane’s theory. Dilution and its cost is inserted directly into cutoff grade optimization process. The cutoff grades obtained using suggested method will be more realistic rather than ones by using the original form of the Lane’s formulation. Results of the study showed that with an increase of dilution, average grade decreases and consequently the cutoff grade increases. As a result of dilution, the quantity Q m increases and the quantities Q c and Q r decrease. Therefore, the annual profit and NPV of project is very significantly reduced. 相似文献
19.
内蒙古锡林郭勒盟乌兰图嘎锗矿地质特征及勘查工作简介 总被引：9，自引：0，他引：9
乌兰图嘎锗矿是在内蒙古自治区境内首次发现的与褐煤共生的特大型锗矿床,计算锗金属量达１６００ 余吨。该矿床不仅规模大、品位富,而且矿床地质条件简单,埋藏浅、易露采。本文将该矿床成矿地质背景、矿床规模、形态及其品位变化,锗的赋存状态、富集规律等地质特征,和矿床地质勘查工作及锗煤提锗加工技术等主要内容作一简单介绍 相似文献
20.
Ore grade is the most important source of uncertainty in a mining operation which plays an important role to classify run-of-mine (ROM) material into ore and waste parcels. As a widely used method, kriging estimator is used to estimate the grade of ore blocks. In conventional mining practices, if the estimated grade of a parcel is above the cut-off grade, this parcel is classified as ore, otherwise, is labelled as a waste parcel. An alternative approach is to simultaneously consider the grade of parcels and the economic consequences of sending parcels to destinations by applying simulation-based methods. In this study, kriging and simulation-based methods including loss and profit functions are applied on a real-world case study to classify ore/waste material based on the initial exploration data. Then, the actual known data, collected from blast holes samples, are compared with the estimated results in order to validate the performance of the presented methods. Outcomes show that simulation-based methods can perform better and show more adjustability with real data. 相似文献