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By Y. C. Kim

Using an exhaustive data set of Walker Lake, four different kriging techniques plus the inverse distance squared weighting were compared with regards to each one's performance in accurately estimating the block grades. The North-West quadrant of the Walker Lake data area was used because of its extreme variability of values and its distinct contour of the values. There were 1900 exhaustive data points in the selected area from which a total of 121 samples were drawn following the sampling strategy given in Isaaks and Srivastava (1989). The average of 5 x 5 exhaustive data points was treated as the true, known block grade. A total of 780 blocks, each block corresponding to the average of 5x5 exhaustive data points, were then estimated using the 121 sample points. The resulting estimates were then compared with the true known values to determine each technique's prediction performance. For this particular portion of the Walker Lake and for the given sampling strategies used, the obtained results for the global estimation are mixed. For the variable U which is much more variable, the rankings are; 1) Jackknife Kriging (JK), 2) Indicator Kriging (IK), 3) Inverse Distance Square weighting (IDS), 4) Ordinary Kriging (OK), and 5) Log-Jackknife Kriging (LJK). For the variable V, the results are; 1) OK, 2) IK, 3) JK, 4) LJK, and 5) IDS. When we apply several cutoff grades to the estimates to determine the conditional mean grades and tonnage, the above rankings generally get shifted around. Two exceptions to these cases are; a) UK for U and b) IDS for V. These two consistently ranked at the bottom.

Jan 1, 1995

By Chris Lynagh, Collin Schroeder

Determining the best excavation method is a critical step in successful tunnel construction. In rock tunneling, several factors can dictate the excavation method, such as: (1) rock characteristics, (2) tunnel size and length, (3) nearby utilities/infrastructure, and (4) contractor’s preferred means and methods. This paper discusses the various rock tunnel excavation methods utilized on the Doan Valley Storage Tunnel Project (DVT), a project constructed as part of the broader Project Clean Lake in Cleveland, Ohio. The differences between each method’s initial and final lining, geology, and cycle sequence will be analyzed and compared.

Jun 13, 2023

By Ruari Soutar-Dawson, Fisher Wang, Alan Boylston, Michael Denzel

Vertical stirred mills are increasingly used for fine grinding applications in the mineral processing industry due to their high energy efficiency. Thus, modeling power draw is of great interest proven by the effort in previous work including analytical models. In this contribution the development of a DEM-CFD coupled model is presented to determine power draw under different operating conditions. These include grinding media filling level, shaft speed and fluidization as well as changes in grinding compartment configuration. An extensive test program on an especially equipped test mill is initiated to validate the model.

Feb 22, 2026

By Gary W. LaChapelle

Cyprus Miami Mining Corp. has a history of overcoming adversity through innovation and adaptation to changing conditions. Requirements to remain profitable in the 1990s include a combination of advanced technology, employee involvement and training, attention to customer satisfaction, environmental awareness and quality management. The Miami property is located in the Globe-Miami area of Arizona, 130 km (80 miles) east of Phoenix and 160 km (100 miles) north of Tucson. The complex is located in a high desert environ¬ment at an elevation of 1065 m (3500 ft). The region receives about 480 mm (19 in.) of precipitation annually. History Mineralization at the Miami property was first discovered in the 1880s, which led to underground mining of copper by the 1890s. In 1911, the Inspiration Consolidated Copper Co. was formed by combining the Inspiration and Live Oak Mines. Full-scale production began in 1915. Block caving methods were used at both mines. Open-pit mining commenced in 1948. Underground mining had ceased by 1954, and all production was obtained from surface operations. Innovation has been the key to Miami's success. Development of sulfide flotation and the ferric cure process for vat leaching were advanced at Miami. In situ leaching of oxide material, remaining after block caving had removed the sulfide ore, was also used.

Jan 1, 1993

By Cheng Zhengbing, Sun Baoqi

This paper summarizes several chemical purification methods used for producing high-pure industrial minerals These methods, mainly including alkali melting, acid leaching, oxidation-reduction bleaching, are respectively used to eliminate the impurities such as silicates in graphite and diamond, ferric oxides in quartz sand or other valuable silicate minerals, colouring impurities in kaoline, barite and other minerals which are required to have a high-whiteness. The fundamentals of the chemical purification methods and some practical examples in China are introduced in the paper.

Jan 1, 1995

By Thomas Novak, Philip Johnson, Richard L. Sanford, Lloyd A. Morley

Macintosh use in mine-planning applications lags DOS machines since many users have made significant investments in hardware and training for other environments. Macintosh use is becoming more pronounced in many other industries, and com soft-ware is of at least the quality of that available for DOS machines and many workstations. This paper describes attributes of the Macintosh computer family as related to many mine-planning problems and solutions including software, memory considerations, workstations, DOS compatibility, and networking.

Jan 1, 1993

By Jacob Petersen, Jon J. Kellar, Samuel Kessinger, Kiran Green

 The paper demonstrates that Belle Fourche Shale (BFS), an abundant shale, can be transformed into a ceramic through careful characterization and thermal processing. The study explores the potential of BFS ceramics for use as refractories and thermal energy-storage devices, highlighting their high thermal storage capacity, good thermal shock resistance, and cost-effectiveness.

Dec 1, 2023

By Julia R. Budden

The role of bacterial oxidation in the mining industry is becoming more widely accepted. Western Australia has accepted the technology as a pretreatment for refractory gold concentrates more readily than most. The third of such plants has been completed at the Y ouanmi Gold Mine. This is situated approxi­mately 500 kilometres north east of Perth, in the Yilgarn mineral field. Y ouanmi concentrates are produced from underground ore and contain arsenopyrite and pyrite as the main sulphide miner­als. Refractory gold from this deposit is generally associated with the arsenopyrite portion of the material. Gold Mines of Australia Ltd ("GMA") initiated pilot scale testing at the BacTech premises in November 1993. The decision by GMA to use BacTech's technology was announced in February 1994. Design and construction commenced at this time. Bacterial growth on site was initiated in July 1994 and continuous opera­tion began in the October. Concentrate was added at 0.5 tonnes per hour and this has increased to 1 tonne per hour.

Jan 1, 1995

By Q. X. Yun, S. H. Liu

This paper provides a new approach to determine the opening layout in underground mining methods by means of genetic programming. Based on a set of random combination of openings, the layout of openings will gradually improve with the help of genetic operations, including reproduction, crossover, mutation and fitness calculation. The optimal solution will finally emerge according to Darwinian principle: "the survival of the fittest ".

Jan 1, 2002

Those who have had an occasion to apply geostatistics to the estimation of ore reserves are familiar with the conventional approaches of estimating average grade of quality values for arrays of regular grid squares or blocks. Further, the technology to perform geostatistical analysis and prediction for irregular two-dimensional areas has been available in a practical, readily useable form for some time. However, the generalization of this technology into three dimensions has been hampered by lack of a suitable geometrical characterization for realistic, three dimensional shapes and volumes. The extension of these estimation techniques into three dimensions has now been made possible by a successful integration of the volume modelling capabilities of 3D Component Modelling with proven 3D Geostatistical Techniques. The result is a powerful new technique for mineral ore reserves estimation in a practical, useable form. The technique allows direct geostatistical estimation of grade and quality values for precisely defined, irregular, realistic, geological, and mining shapes or volumes. This paper describes the two technologies, their integration and their application in practice to the estimation of mineral ore reserves. The paper closes with a discussion of the benefits provided by the new approach, in terms of accuracy, efficiency and practicality.

Jan 1, 1991

By Barry T. Kilbourn

Yttrium Oxide is versatile; it is essential for television phosphors, for microwave garnets, for laser crystals and for high-performance ceramics, to name but a few advanced applications. When produced commercially, the material must satisfy not only stringent specifications regarding chemical purity but, increasingly, also meet closely defined physical parameters. The techniques needed for its production range from solvent extraction to carefully controlled precipitation and calcination. The processing steps from mineral concentrate to pure oxide will be described and related to the final oxide. The simple word "material" has complex connotations; it means, to paraphrase "Alice", exactly what we want it to mean. Throw in the label "advanced" and the picture darkens further! Just what is an advanced material and how does it differ from a common-or-garden material?

Jan 1, 1990

By J. Craynon, M. Karmis

Previous papers by the authors have presented a systems-engineering approach based on the premise that systems can only be optimized if all factors are considered and integrated into mine planning. This paper discusses the challenges inherent in optimizing the design of large-scale surface coal mining operations in Appalachia. Regulatory and permitting programs in the United States often focus on single parameters, rather than the full suite of desirable outcomes for sustainability. By utilizing geographic information system (GIS) tools to evaluate available data on environmental and social resources, the regulatory barriers which prevent operations from incorporating ecological and other sustainable development concerns into coal mine sustainability performance were identified. By analysis of the on-the-ground issues related to sustainability, the key parameters to be incorporated into an optimized coal mine design in Appalachia are discussed along with possible changes to the regulatory framework that would enhance incorporation of sustainability into coal mine design.

Jan 1, 2011

By L. Zhou, D. Bahrami, Y. Xue

Underground mine fires are a threat to the safety and health of mine workers. The timely determination of the location and size of an underground fire is of great importance in developing firefighting strategies and reducing the risk of any injuries. Machine learning was used in this paper to develop a predictive model for fire location and fire size in an underground mine. The ventilation data were obtained by simulating different mine fire scenarios with MFire. The ventilation data of all airways were used as features to predict the fire location. Based on the feature importance, five airways were selected to monitor, and the airflow data of the selected airways were used to predict the fire location and fire size. An accuracy score of 0.920 was obtained for the prediction of fire location. In addition, in-depth analyses were conducted to characterize the wrong predictions with the purpose of improving the performance of the random forest model. The results show that the occurrence of fire at closely connected airways at some locations can generate misleading ventilation data for each other and the model performance can be further improved by grouping them. Fire size is another factor affecting the model performance and the model accuracy increases with increasing fire size. The result from this study can help mine safety personnel make informed decisions during a mine fire emergency.

Mar 2, 2022

Numerous underground coal mine ventilation seals have been installed in the United States of America prior to 2006 and after implementation of the Mine Improvement and New Emergency Response (MINER) Act. Seal engineering, design, placement, and construction is regulated in industry, but post-construction monitoring of seals is limited to visual inspection of the outby face and seal perimeter, convergence measurement, and atmospheric monitoring. To monitor seal integrity and to provide safe working conditions, a form of non-destructive testing (NDT) is necessary to accurately reflect the health of the seal by detecting post-construction changes, deterioration, or defects within in-situ seals in underground coal mines. Previous research from the National Institute of Safety and Health (NIOSH) has indicated the potential for utilizing ground penetrating radar (GPR) for assessing in-situ mine seals. This paper provides an update to the assessment of proposed NDT methods for seal evaluation using commercially available GPR technologies and systems. Full-scale free-standing seals and large-scale seal specimens were analyzed with an array of GPR units from various manufactures using multiple frequencies.

Feb 23, 2014

By Roger L. Baer

Introduction Brief Review -SEC mission & history -Development of SEC mining disclosure guidelines -Principles of good public company ‘disclosure’ SEC staff views of alternative approaches to mining company disclosure -SME Resource & Reserve Committee – April 2003 Food for thought

Jan 1, 2003

By C. V. Deutsch, O. Babak

A longstanding problem in geostatistics is that kriging usually assigns significantly greater weights to end samples in strings of data than it does to central samples. These weights are theoretically valid, but suboptimal estimates may result when there are geological trends in the variable near contacts, that is, large weights may be applied to samples that are systematically lower or higher than average. A number of ad-hoc corrections exist, each with pros and cons; none are fully automatic with a well-defined measure of optimality. A new method for estimation in a finite domain is proposed. This method is referred to as finite domain kriging. The method is based on kriging with a successively larger number of data. The total number of relevant data (n) is established, and then n kriging matrices are solved. The first matrix has the closest single data value (n-1 weights are set to zero); the second has the two closest data (n-2 weights are set to zero) and so on. The final matrix has all n data. The kriging weights used for estimation are the average of the weights from the n successive kriging runs. Each kriging run is optimal, yet with different smoothing and a different treatment of data at the end of the strings. The result is a set of weights that does not give undue influence to data values at the end of strings. The methodology is developed with examples. Cross validation shows that finite domain kriging outperforms conventional kriging.

Jan 1, 2009

By William G. Freeman

In comparison to many mineral commodities, barite has a low unit value. It is mined and sold in low volumes in high-grade (90-98% BaSO4) forms to basically one industry that uses approximately 75% of the free world production. Based upon the above criteria, all factors must be considered in determining if a barite deposit is economical; such as, the type of deposit, mining and milling methods required, transportation to the markets, tariffs, local political conditions, etc. In other words, barite mines are made--not found. The length of this paper precludes any indepth discussion of geology, mining and metallurgy of barite. Most of this information can be found in data already published, such as D. A. Brobst's bulletin1 on the Barite Resources of the United States.

Jan 1, 1971

By Michael G. Strominger, Anthony E. Gross

The development of precious metals ore agglomeration with a cement binder, by the U.S. Bureau of Mines, has allowed the economical heap leaching of low grade gold ores (<0,05 oz/ton) over the last decade, Even with the Bureau of Mines technology, numerous operations continue to experience channeling and blinding problems. A research project was undertaken at Nalco Chemical to address situations where improved agglomeration is needed, By increasing the incorporation of fines into the agglomerates,the segregation of ore by size which occurs from handling will be reduced and channeling minimized. A stronger agglomerate will reduce fines migration during leaching and prevent blinding of the heap, Both of these changes will give an even flow of barren solution throughout the heap and give solution contact with all of the ore. This paper presents the development of polymeric agglomeration aid, Nalco 9760 which has given a higher rate of and a higher total gold recovery in plant evaluations.

Jan 1, 1990

By G. A. Swanquist

INTRODUCTION This article describes the yellow cake drying, packaging and dust collection circuit of the United Nuclear Church Rock Mill. It also describes the layout and floor plan of this section as well as the operation and performance of the various equipment. In order to place the yellow cake section in perspective of the mill as a whole, the mill circuit is described briefly. CHURCH ROCK MILL GENERAL DESCRIPTION The Church Rock Mill contains six operating sections shown in Figure 1 in block diagram form. The grinding section consists of a semi-autogenous mill in closed circuit with a hydrocyclone. The slurry is then routed to the leaching tanks. Sulfuric acid and sodium chlorate is added to dissolve the uranium. The pulp is transferred from the leach tanks to the thickeners where the uranium bearing liquid is separated from the barren solids. The uranium bearing solution is then filtered and pumped to the solvent extraction section. [ ] In the solvent extraction section, the uranium bearing aqueous solution is brought into contact with an organic solution composed of kerosene, amine and isodecanol. The amine extracts the uranium from the aqueous solution. This organic solution is then routed to the stripping section, where the uranium is removed from the organic solution with an ammonium sulfate aqueous solution. The pregnant stripping solution now concentrated to 30 gpl U308 is routed to the precipitation tanks where ammonia is added to precipitate the uranium. The yellow cake is then washed in a counter current circuit of two thickeners and one centrifuge to remove impurities, mainly sulfates in order to meet specifications. The centrifuge centrate is routed to the second wash thickener for forward wash. The centrifuge cake at approximately 50% solids consistency is transferred to the yellow cake dryer via a screw conveyor. YELLOW CAKE DRYING, PACKAGING AND DUST COLLECTION Figure 2 shows the flowsheet of the integrated circuit of drying, packaging and dust collection. This section of course centers around the yellow cake dryer as the main equipment. The other main units are the dust collectors for the dryer and packaging respectively, a yellow cake storage bin and the yellow cake packaging facilities. Physically, all of this equipment occupies four floors, beginning at the top floor: 1. Both dust collector fans, the centrifuge and the screw conveyor to transport the yellow cake to the dryer. 2. The dryer, fire box and both dust collectors occupy the third floor. Figure 3 shows the floor plan of the third and fourth floors. 3. The yellow cake storage bin and dryer dust collector sump are located on the second floor. 4. The ground floor houses the loading facilities consisting of two load out ports from the bin to barrels, a roller conveyor loop, drum weighing scale, and change room facilities. Figure 4 shows the ground floor plan. Figure 5 is an elevation view of this section showing the overall equipment arrangement.

Jan 1, 1981

The sixth annual conference of the Mineral Economics and Management Society (MEMS) was held Feb. 27 through March 1 in Boulder, CO. This year&apos;s event was attended by more than 100 academic, industrial, government and other professionals interested in mineral economics and materials management. With about 250 members worldwide, this not-for-profit society seeks to promote scientific and economic analysis of current relevant issues. This year&apos;s program was sponsored by Alcan, Bateman Engineering, Cyprus Amax Minerals, J.P Morgan, Knight Piesold LLC and Newmont Gold. The conference&apos;s technical program consisted of six sessions. These included "Financial tools for a changing world," "Access to minerals," "Comparing North and South America," "Environmental issues in today&apos;s world" and "Transporting minerals." The program was concluded with a panel discussion titled "National minerals policies in Asia." In addition, a student papers session was held, in which students were given the opportunity to compete for a $1,000 award. The following is a brief review of the technical pro¬gram.

Jan 1, 1997