Ore value-tonnage diagrams for resource assessment

An ore value-tonnage diagram has been proposed for assessing mineral resources. Diagrams of W+Mo, and Pb+Zn deposits show a good linearity between ore value and logarithms of cumulative ore tonnage. Diagrams of the massive sulfide, orthomagmatic, placer, porphyry, replacement, and stratabound types are also linear. It is assumed, therefore, that deposits of each of these commodities and these types belong to a single population. In contrast, the ore value-tonnage relations of all the deposits analyzed here is approximated by the combination of two exponential functions. The same feature is seen for deposits of the Cu+W+Mo, Cu+Pb+Zn, and Au+Ag commodities, and of the vein and unconformity-related types. This suggests that deposits belonging to each of such categories are divided into the high and low value groups. We can expect, accordingly, to find high value deposits of such categories.     

Radial Basis Function Network for Ore Grade Estimation

This paper highlights the performance of a radial basis function (RBF) network for ore grade estimation in an offshore placer gold deposit. Several pertinent issues including RBF model construction, data division for model training, calibration and validation, and efficacy of the RBF network over the kriging and the multilayer perceptron models have been addressed in this study. For the construction of the RBF model, an orthogonal least-square algorithm (OLS) was used. The efficacy of this algorithm was testified against the random selection algorithm. It was found that OLS algorithm performed substantially better than the random selection algorithm. The model was trained using training data set, calibrated using calibration data set, and finally validated on the validation data set. However, for accurate performance measurement of the model, these three data sets should have similar statistical properties. To achieve the statistical similarity properties, an approach utilizing data segmentation and genetic algorithm was applied. A comparative evaluation of the RBF model against the kriging and the multilayer perceptron was then performed. It was seen that the RBF model produced estimates with the R ² (coefficient of determination) value of 0.39 as against of 0.19 for the kriging and of 0.18 for the multilayer perceptron.     

Correction to: Projection of Iron Ore Production

Natural Resources Research - The original version of this article unfortunately contained an error in Equation 3.     

Applying Four Different Risk Models in Local Ore Selection

Given the uncertainty in grade at a mine location, a financially risk-averse decision-maker may prefer to incorporate this uncertainty into the ore selection process. A FORTRAN program risksel is presented to calculate local risk-adjusted optimal ore selections using a negative exponential utility function and three dominance models: mean-variance, mean-downside risk, and stochastic dominance. All four methods are demonstrated in a grade control environment. In the case study, optimal selections range with the magnitude of financial risk that a decision-maker is prepared to accept. Except for the stochastic dominance method, the risk models reassign material from higher cost to lower cost processing options as the aversion to financial risk increases. The stochastic dominance model usually was unable to determine the optimal local selection.     

从硫酸锂粗矿中分离富集锂的实验研究

针对从西藏查波措盐湖卤水中获得的硫酸锂粗矿,开展从该矿物中分离提取锂的研究。根据该矿物的组成,设计了去除与锂离子共存的镁、硫酸根等主要离子的工艺路线,通过除镁、硫酸根、钙等过程和蒸发浓缩、结晶分离等步骤,得到了杂质离子含量较低的富锂溶液。实验对除镁步骤的加水量、加料方式、反应时间、Ca O加入量等反应关键控制因素进行了考察,确定了较优的分离条件。     

肯德可克金钴铋矿石选矿实验

采用预处理—浸出工艺技术,解决了该矿床半氧化矿石中Au、Ag、Co、Ni、Cu、Mo、Bi的选矿技术,使Au、Ag、Co、Ni、Cu、Mo的浸出率达90%以上,Bi的浸出率85%以上。     

A Chart for Judging Optimal Sample Spacing for Ore Grade Estimation

Mineral deposit grades are usually estimated using data from samples of rock cores extracted from drill holes. Commonly, mineral deposit grade estimates are required for each block to be mined. Every estimated grade has always a corresponding error when compared against real grades of blocks. The error depends on various factors, among which the most important is the number of correlated samples used for estimation. Samples may be collected on a regular sampling grid and, as the spacing between samples decreases, the error of grade estimated from the data generally decreases. Sampling can be expensive. The maximum distance between samples that provides an acceptable error of grade estimate is useful for deciding how many samples are adequate. The error also depends on the geometry of a block, as lower errors would be expected when estimating the grade of large-volume blocks, and on the variability of the data within the region of the blocks. Local variability is measured in this study using the coefficient of variation (CV). We show charts analyzing error in block grade estimates as a function of sampling grid (obtained by geostatistical simulation), for various block dimensions (volumes) and for a given CV interval. These charts show results for two different attributes (Au and Ni) of two different deposits. The results show that similar errors were found for the two deposits, although they share similar features: sampling grid, block volume, CV, and continuity model. Consequently, the error for other attributes with similar features could be obtained from a single chart.     

东昆仑迪木那里克铁矿地质特征与找矿标志

迪木那里克铁矿位于阿尔金大断裂南侧,矿体主要赋存于中-上奥陶统祁曼塔格群浅变质的碎屑岩-火山碎屑岩中.矿体多呈似层状、条带状产出,部分矿体塑性变形较强,矿体与地层产状基本一致,层控作用比较明显;矿石主要为条带状石英-磁铁矿和块状磁铁矿矿石;矿石品位较低(TFe=20%～40%);围岩蚀变特征明显.该铁矿属沉积变质型铁矿.综合研究发现,可利用矿区地层、构造、岩石蚀变情况、航磁异常等作为矿区和区域找矿标志.     

大柴旦低品位硼矿的富集研究

在对大柴旦盐湖湖底低品位硼矿的组成、伴生矿物种类、含量等因素进行分析的基础上,依据各矿物物理性质的差异,通过正交试验法,确定采用旋流方法分离低品位硼矿中的石膏和碳酸盐,分别得到以碳酸盐为主要杂质的低品位硼矿和以硫酸盐为主要杂质的低品位硼矿,然后进行分别加工,有效降低大柴旦盐湖低品位硼矿加工过程分解剂的消耗,为大柴旦盐湖低品位硼矿的加工利用提供了一条新的途径。     

东昆仑迪木那里克铁矿地质特征与找矿标志

迪木那里克铁矿位于阿尔金大断裂南侧,矿体主要赋存于中-上奥陶统祁曼塔格群浅变质的碎屑岩-火山碎屑岩中.矿体多呈似层状、条带状产出,部分矿体塑性变形较强,矿体与地层产状基本一致,层控作用比较明显;矿石主要为条带状石英-磁铁矿和块状磁铁矿矿石;矿石品位较低（TFe=20%～40%）;围岩蚀变特征明显.该铁矿属沉积变质型铁矿...     

Geometallurgical Domaining by Cluster Analysis: Iron Ore Deposit Case Study

Natural Resources Research - Geometallurgy integrates many aspects of geology, mineralogy, resource modeling, mine planning, metallurgy, and process control to optimize mining operations....     

硼氢化物是形成硼矿床的重要迁移形式

经对硼氢化物的形成条件、内生硼矿物化学成分、矿物共生组合及盐湖卤水、热泉的有关物质浓度值研究后 ,认为硼氢化物是形成硼矿床的重要活化、迁移形式     

氯化钾生产中提高原矿使用率的研究

针对氯化钾生产中不同类型的光卤石原矿,因其镁钾比和钠钾比失调,而影响浮选工艺的控制,使最终产品质量和收率低下,不能使原矿得到充分有效利用。通过原矿的掺兑可以改善原矿的组成结构,并可调整原矿镁钾比和钠钾比。比例掺兑后不仅使原矿得到有效回收和利用,也大幅度提高了最终产品氯化钾的质量和产量,在实际生产中具有积极的推动作用。     

Spatial Pair-Copula Modeling of Grade in Ore Bodies: A Case Study

A real-world mining application of pair-copulas is presented to model the spatial distribution of metal grade in an ore body. Inaccurate estimation of metal grade in an ore reserve can lead to failure of a mining project. Conventional kriged models are the most commonly used models for estimating grade and other spatial variables. However, kriged models use the variogram or covariance function, which produces a single average value to represent the spatial dependence for a given distance. Kriged models also assume linear spatial dependence. In the application, spatial pair-copulas are used to appropriately model the non-linear spatial dependence present in the data. The spatial pair-copula model is adopted over other copula-based spatial models since it is better able to capture complex spatial dependence structures. The performance of the pair-copula model is shown to be favorable compared to a conventional lognormal kriged model.     

Copper Ore Quality Tracking in a Belt Conveyor System Using Simulation Tools

Natural Resources Research - The ore quality at mining faces in the KGHM underground copper ore mines can be determined based on channel samples and block models built in the Datamine system....     

砂铁矿土壤种子库组成及出苗规律研究（英文）

砂铁矿的开采对周边荒漠草地产生较大影响,土壤种子库极度破坏,曾经的荒漠草场利用率和生产力几乎为零,严重影响了当地畜牧业发展和生态环境安全。人工补充土壤种子库对生态修复后荒漠草地物种组成影响十分重要。本研究以平整后的砂铁矿为研究对象,采用室内发芽盘方法,对比分析了砂铁矿土壤种子库人工补充前后出苗规律及物种组成以及种子埋深对出苗率的影响,结论认为：(1)青河县砂铁矿区原始土壤种子库仅包含4种植物,均为一年生藜科植物,优势种为刺沙蓬和虫实,且土壤种子库密度非常小;(2)研究区土壤种子库出苗与水分关系密切,增加水分,一年生植被出现“爆发式”出苗现象;(3)种子埋深影响多年生植被出苗率,0-5cm是出苗的最佳埋深。播深合适的情况下,人工补充土壤种子库在7天就可以完成出苗,这些结论均为修复时选择物种及大面积推广提供依据和奠定基础。     

Geostatistical Modeling of Ore Grade Distribution from Geomorphic Characterization in a Laterite Nickel Deposit

Due to growing consumption of nickel (Ni) in a range of industries, the demand for Ni has increased rapidly around the world. This trend requires a more precise estimation of available Ni grade deposits and an identification of factors controlling the grade distribution. To achieve these requirements, this study applies geostatistical techniques to spatial modeling of the Ni grade in a laterite Ni deposit, with reference to geomorphic features such as slope gradient and the thickness of limonite and saprolite zones. The Sorowako area in Sulawesi Island, Indonesia, was chosen as a case study area because it has a representative laterite Ni deposit with large reserves. Chemical content data from drillhole cores at 294 points were used for the analysis. The slope gradient was found to have a remarkable correlation with the thickness of the limonite zone, but there was no correlation between the thickness of the limonite and the saprolite zones above the bedrock. One important feature was a general correlation between the thickness of the saprolite zone and the maximum Ni grade in this zone: the grade increases with the thickness of the zone. Co-kriging was adopted to incorporate this correlation into estimating the maximum Ni grade in the saprolite zone. As a result, the maximum Ni grade in the saprolite zone tends to be high mainly in areas of slight slope. The Ni accumulation at this topographic feature probably originates from deep weathering by groundwater infiltrating through well-developed rock fractures.     

A Chart for Judging Optimal Sample Spacing for Ore Grade Estimation: Part II

Natural Resources Research - Resources of mineral deposits are commonly estimated using data extracted from rock cores obtained by drilling. Information of good quality and quantity is essential to...