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By Yong Pan, Srivatsan Jayaraman Sridharan, Purushotham Tukkaraja

Block cave mining method poses unique ventilation challenges compared to other underground metal mining methods. This research study focuses on assessing the airflow behavior in regulated airflow distribution systems by developing a 1:100 scaled block cave experimental model and a numerical model. This study also investigated gas flow behavior under various airflow conditions. Based on our findings, we observed that reduction in particle size and porosity of caved materials, decrease in cave footprint, and closure of undercut drifts would increase cave airflow resistance. The increased airflow is found beneficial for gas dilution regardless of its source locations, while the regulated airflow distribution system might deteriorate gas dilution situation when the source is located in the extraction drifts.

May 12, 2022

By Henry E. Reed

This presentation is about a small company, Industrial Mineral Products, that was formed in 1972 with one product and one customer and by a series of value-added changes avoided disaster and increased sales many times over. The principal of the company stopped by my office in Seattle looking for industrial mineral opportunities in the Northwest. We got together and went through all the minerals in Ladoo's "Industrial Minerals" from Abrasives to Zircon to see if we could find something available on the vast holdings of the Burlington Northern. At that time one of our lessees was operating a silica sand mine near Ravensdale, Washington and indicated that he might be interested in selling out. This sounded interesting to my client and within two weeks the transaction was completed.

Jan 1, 1990

By Gabriel E. Zárate, Juan C. Guzmán

In Chile there are significant amounts of gold in flotation tailings that could be recovered, being heap leaching the most promising alternative. In order to determine the feasibility of treating these tailings by this method, a detailed study is carried out using 4 representative samples. After defining the best conditions an economic evaluation is done for a plant treating 200 tpd, sensibilizing with respect to parameters such us gold price, tailing grade and capital costs. The results show that it is technically feasible treat these gold tailings by heap leaching with gold extractions over 70 %. It is also economically feasible for gold grades higher than 0.5 g/t and gold prices over 350 US/oz.

Jan 1, 1987

By Lee Ann Arrington-Webb

Thiele Kaolin Co. has invested much time and money in achieving and maintaining its IS0 9002 certification. Through a regimen of process control and documentation, routine audits and a commitment to quality management, this kaolin producer is a competitive pigment supplier in a worldwide market. Background In 1987, the International Organization for Standards developed the ISO 9000 quality management system. This series of standards is used as a means to ensure customers that a quality management system is in place. Certification of a company does not mean that an individual product is of high quality. Rather, it demonstrates a supplier's ability to meet its customers' product and service needs. It also shows that a company has documented records to assure product consistency. The ISO 9000 system was begun in England during the early 1980s. During the mid-1970s, the British manufacturing industry was experiencing low quality. In an attempt to boost quality standards, the British government established the BS 5750 standards system. In 1987, BS 5750 was incorporated into ISO 9000. The ISO 9000 series consists of three levels of certification. ISO 9001 is the model for quality assurance in "design/development, production, installation and servicing." This standard applies to companies that rely on research and development to bring products that frequently change to market. ISO 9002 involves "production and installation" only. This standard is relevant to industries that produce a specific product according to specifications - either their own or their customer's. ISO 9003 is the model in "final inspection and test." This standard is the least detailed of the 9000 series. It is also the most applicable to companies that purchase, inspect or sort and resell. The quality system requirements for certification are outlined in the 18 elements of ISO 9002. These include: 4.1 - Management responsibility. 4.2 - Quality systems. 4.3 - Contract review. 4.4 - Design control. 4.5 - Document and data control. 4.6 - Purchasing. 4.7 - Control of customer-supplied product. 4.8 - Product identification and traceability. 4.9 - Process control. 4.10 - Inspection and testing. 4.11- Control of inspection, measuring and test equipment. 4.12 - Inspection and test status. 4.13 - Control of nonconforming product. 4.14 - Corrective and preventive action. 4.15 - Handling, storage, packaging, preservation and delivery. 4.16 - Control of quality records. 4.17 - Internal quality audits. 4.18 -Training. Continuous improvement, though implied in maintaining these requirements, could potentially be included in the quality system requirements in the next revision. The ISO 9000 requirements and documentation system is shown in the hierarchy pyramid (Fig. 1). A company's quality policy serves as the top of the pyra-

Jan 1, 1997

By R. D. Herron

Mining coal under deep cover conditions is certainly the proper phrase to use in describing one of our newest operations. Located in the southwest corner of Virginia is this operation which is the Beatrice Mine of the Beatrice Pocahontas Company, a joint venture of Republic Steel Corporation and Island Creek Coal Company. The mine is working in the No. 3 Pocahontas seam in an assigned area of over 9500 acres containing over 60 million tons of recoverable, high quality, low volatile coal. The site of the mine opening was at Keen Mountain, Virginia, where the seam lay 1350 feet below the surface. This depth, greater than anything attempted thus far in the coal industry on this continent, would pose some problems, we felt, with which we had not previously had to contend.

Jan 1, 1968

With the dawning of a new century came the beginning of a new era in the coal industry. Instead of the traditional practice of only buying and selling produced coal in the United States, a coal futures market was established. The New York Mercantile Exchange began trading coal futures in July 2001. But, even in this new era, many of the old is-sues that have beset the coal industry still remain, as was evident in2001. Coal production increased to are cord level during 2001, according to preliminary data from the US Energy Information Administration(EIA). Production in 2001 rose by4% to 1.01 Gt (1.12 billion st), compared with 2000 (Table 1). This barely surpassed the previous record level of 1 Gt (1.11 billion st)set in 1998. Coal consumption remained unchanged. The additional production was used to replenish the depleted stockpiles that had resulted after two years of declining coal production and increasing coal consumption.

Jan 1, 2002

By Robert C. Sutter

In 1958, it became obvious to some of us in the solution mining business that there were certain problems in connection with our sodium chloride brining operations which were industry- wide. These were the types of problems which, while they were important to the safe and economical operation of our salt brining operations, were not such that their solutions would give an individual company a great competitive advantage over his competitor; and since they involve the safe and efficient mining of a natural resource, it was obvious that the answers would, in any event, be shared industry-wide. Since we were dealing with underground solution mining and, consequently, unseen and remotely controlled operations, the problems are formidable and the solutions difficult. While all of us were doing work to improve our operations, none of us could justify the expenditures necessary for basic research in these areas. Consequently, the idea was conceived of research sponsored by many companies with the same problems. In 1960, 11 companies entered into a' formal agreement to jointly support research on a specific problem of sodium chloride solution mining. The project to be undertaken was the development of a method for measuring the size and extent of underground solution cavities in sedimentary salt beds. It was agreed that all research was to be performed by independent research organizations. A part-time consultant or administrator was retained to administer the research contracts and to provide technical advice.

Jan 1, 1966

By Randal J. Barnes

The January 1988 issue of Engineering and Mining Journal includes two short articles on blasting practices in surface gold mines (Anon., 1988 ; Carr , 1988). A reader of these articles learns, among other things, that a "12 x 13 ft" blasting pattern is used at the Carson Hill Mine, and a "17-ft burden and 18-ft spacing" is used at Echo Bay Mineral's Borealis operation, while at Mascot's Nickel Plate Gold Mine "ore shots are on a 10 x 10 ft" pattern. Like a new edition of the World Book Almanac, these articles are overflowing with useful tidbits of technical data; but, they never mention why the particular blasting patterns were selected. A survey carried out during the Winter of 1988 at six surface gold mines in the western United States also failed to produce a satisfactory answer. The responses from mine planning engineers to the question "why is your blasting pattern X by Y", reduced to "we use X by Y here because we used X by Y at our last operation, and it worked ok." Certainly, with the available decades of experience and professional practice in blast holes design, rock fragmentation in surface mines has been thoroughly investigated. However, and this is the central issue, fragmentation of the rock is not the primary purpose of most rotary drill holes in surface gold mines. Quoting senior mine engineers from companies operating, three of the richest surface gold mines in the world (AMAX Gold, Homestake Mining, and Gold Fields Mining)

Jan 1, 1989

By G. Markopoulos

Every year thousands of people from all over the world come to Mount Parnasse, visiting Delphi, the Parnasse ski-resort and other sights in the area of Fokida, available to all ages all year round. This region of Greece, is not only gifted with natural beauty, but also with valuable underground natural wealth: inside Mount Parnasse and the adjoining Ghiona Mountain, there are rich bauxite deposits - the ore from which aluminium is made. In this magnificent part of our country, any mining activities undertaken must be adapted to coexist within such an ecologically sensitive area. This demands an enormous effort, knowledge and the use of technology. This is definitely our Company's primary objective. Our company's (Silver & Baryte Ores Mining Co. S.A.) activities in the area began in 1933, when Euripides Mavrommatis and the two Eliopoulos brothers, Elias and George, established "Bauxite Parnasse SA". Since then, ten thousand people have worked in these ore deposits, and 45 million tons of bauxite have been extracted. The full length of the underground excavations is more than 300 kilometers and 115 million cubic meters of limestone have been extracted on surface mining. In 1996, Bauxite Parnasse merged with Silver & Baryte Ores Mining Co. S.A. Now, the company exports more than 1.500.000 mt per year of bauxite to more than 15 countries around the world, offers a significant amount of job opportunities in the region, and imports valuable exchange into the country.

Jan 1, 2002

By Aditya Rana, A. K. Mishra, M. M. Singh, N. K. Bhagat

Many cases of derailments, train accidents and traffic interruptions due to the slope failure and rockfall have been reported in the past on Konkan Railway trackline because of unstable rock slopes. The authorities installed stability enhancement measures such as wire netting, rock bolting and shotcreting which were found insufficient. The failed geotechnical measures prompted authorities to excavate the unstable slopes. Rock blasting is generally not preferred for the excavation of slopes along the transportation route. Stabilisation and widening of slopes by blasting need closure of the route for a considerable time. Discontinuing traffic on Konkan Railway route was undesirable as it connects two important port cities Mumbai and Mangalore. The paper presents an innovative directional controlled blasting (DCB) technique for excavating three unstable slopes (i.e. cuttings) in hilly terrain without disturbing the traffic. New empirical formulae for small geometry blasting to estimate burden and throw have been developed. A unique sequence of firing and excavation with powder factor varying between 0.04 and 0.39 kg/m3 irrespective of the actual free face was used for rock blasting. The process controlled the throw of blasted material over the track and resulted in a smooth and stable wall. The slope angle has been changed from 80 to 82° to 45–47° and probability of wedge, planar and toppling failures was eliminated. About 100 such accident-prone slopes (52 km cumulative length, 7% of total route) situated at discrete locations along Konkan Railway route were stabilised using the technique. No incident of rockfall and slope failures along these slopes has been observed after the stabilisation.

Maptek, an international development software company, released version 3.2 of its Vulcan three-dimensional mining and geological software package. This latest release is expected to give clients better graphics performance and improved overall solutions. In addition, the company also released the NT version of Vulcan for Unix and personal computers. More than 800 code changes have gone into the 3.2 release, the Lakewood, CO-based company said. Many of these changes were in response to requests from Maptek's customers. Others have been motivated internally by the company to achieve better performance in its Envisage graphics interface. The introduction of hot keys and user-defined menus makes Envisage a more flexible interface and a more productive working environment. A new animation option provides new ways to enhance the organization and display of data. The animated data can include point, string, grid, triangulation and photographic-draped data. The shaft-mapping facility is also included in version 3.2. It enables the cylindrical view of the shaft to be unwrapped and displayed on the screen while the data remains in its true world coordinates. Major upgrades to Vulcan include underground blast design and geotechnical modules. The new blast design module allows the user to develop a ring design in any plane defined by the stope layout. Radial and offset holes can be developed. User-friendly editing tools make adjustments to the initial design a simple task. The user defines the plotting and reporting of rings and plot style templates allow flexibility in reporting. New features in the geotechnical toolbox include options to create daylight windows and pitch lines on the stereo nets. Geotechnical databases can be directly updated from the interpretation of the stereo net. Direct annotation of the symbols on the net is now possible and the stereo net display can be customized. Improvements to the documentation and links within the text have made the on-line help easier to navigate. Maptek also released the NT version of Vulcan soft- ware. The comprehensive design of the software pack- age for Unix and personal computers provides a three-dimensional geological modeling and mine planning system within a natural graphics environment. Users who require the power to manipulate extra- large and complex data sets will still be served by the Unix platform. Users who handle small-to-large datasets can now choose between Unix and personal computer platforms. The NT version will appeal primarily to companies that already have a personal computer network. Response to industry feedback was the basis for developing the NT version. "We want to ensure that our clients receive the optimal product for their needs," said Nicolas Simon, vice president of Maptek in North America. Some advantages of the NT version include: ? Most mining professionals are familiar with the personal computer platform. ? All of the familiar personal computer tools are now available to Vulcan users. ? Resource modeling tools that previously required the powerful Unix workstations have been brought into the personal computer environment. This will help mining companies save money. From a binary data point of view, the personal computer NT version is compatible with other platforms, such as SGIIDECIHPISUN, allowing integrated personal computer and Unix environments For more information, contact Cherie LeDoux, Maptek, 165 So. Union Blvd., Suite 777, Lakewood, CO 80228, fax 303-763-4921, e-mail: info@maptek.com, Internet: http:llwww.maptek.com.

Jan 1, 1997

By Gamal Rashed, Tim Miller, Nicole Evanek

High horizontal stress has been identified as a critical factor affecting roof stability in underground mines, particularly when the immediate roof consists of weak or laminated rock. Numerical models were employed to better understand the influence of caprock thickness, cutting sequences, and the orientation of driving direction relative to maximum horizontal stress on roof stability in underground stone mines. These models were calibrated based on field observations of roof falls from the study mine. The findings of this study enhance our understanding of roof stability under high horizontal stress and contribute to reducing the risk of roof falls in underground stone mines.

Feb 1, 2025

By Aruna Mangalpady, Sandeep Kumar Jeripotula, Govinda Raj Mandela

Injuries due to work-related musculoskeletal disorders (WMSDs) are not uncommon in heavy industry like mining. Researchers acknowledged that occupational exposure to ergonomic risk factors is the chief causative factor in the development ofWMSDs. The aim of this study was to perform an ergonomic assessment of musculoskeletal disorders among surface mine workers in India. Standardized Nordic Questionnaire was used to collect subjective response from 500 workers. A stratified random sampling method according to surface mining work activity type was used to obtain the sample. Data was collected by means of a structured questionnaire, and the Statistical Package for Social Sciences (SPSS) was used to analyze data using descriptive and inferential statistical methods. A response rate of 85% was obtained out of 500 targeted groups. TheWMSDs prevalence for the 12-month period was estimated to be 44.23%. The mean and standard deviation of workers’ age were 41.31and 8.927, respectively. The study has shown that the operators of dumpers, dozers, and graders along with electricians were found to be the most susceptible to developWMSD problems. Among the most affected body parts, back disorder reported the highest. Further, it was found that working with static posture over the longer duration has a significant association with the lower back disorder (with p = 0.020) and bouncing and jarring has also significantly associated with the lower back disorder (with p = 0.023). Similarly, a significant association was found between repetitive work and neck pain (with p = 0.016). The study depicted a significant association between ergonomic hazards and WMSDs, like working with prolonged static posture, bouncing and jarring, and repetitive work.

Mar 13, 2020

By D. Gove

All mining operations using trucks have a common need to properly match the number and size of hauling units (trucks. wagons. scrapers. etc.) to a loading unit (wheel loader. hydraulic shovel/excavator, cable shovel. push tractor. etc.) to provide the best possible fleet match. Optimizing fleet match minimizes the cost per unit of material moved by that fleet. As haul conditions change (haul length. grade. or rolling resistance), there may be need to adjust the number of trucks to maintain the optimum fleet match. Fleet Production and Cost is a tool which, among other things, can be used to optimize the truck-loader match.

Jan 1, 1994

By Yun-tao Xin, Yu Yi, Kang Yan, Gang Li, Xiao-dong Lv

This study investigated the selective removal of arsenic from high-arsenic dust in alkaline systems and the effects of different leaching conditions. The results indicated that the liquid–solid ratio, NaOH concentration, and sulfur dosage had a significant influence on the process. The leaching efficiency of arsenic reached 99.57%, while that of lead was as low as 0.03% under appropriate conditions. In particular, the addition of sulfur can effectively promote the leaching of arsenic and reduce the dissolution of lead in the solutions. An artificial neural network was used to model the leaching process. It consisted of a back-propagation artificial neural network model with a “6–10–2” structure that could effectively simulate and predict the value with more than 99% accuracy. Based on the difference in weights of the different parameters in the neural network model, the relative importance of the parameters related to arsenic and lead leaching efficiency was obtained, which followed the order of NaOH concentration, liquid–solid ratio, sulfur dosage, temperature, time, and stirring speed.

Jul 29, 2021

By John C. Morrisey, Harold M. Ray

With full production from the Casteel Mine in 1987 The Doe Run Company, a wholly owned subsidiary of the Fluor Corporation, encountered a significant increase of copper and iron to the Viburnum Mill. This major change of the lead, zinc, and copper metal ratios in the ore created circuit problems which adversely affected concentrate quality. Recognizing the problem, the company embarked on a metallurgical research program to include laboratory, pilot plant, and plant testing. The program developed an innovative copper prefloat process which both increased copper recovery and significantly improved concentrate quality. The process was tested and first operated at Doe Run's Brushy Creek Mill then installed at the Viburnum Mill in 1992. A brief history of development, plant operating data, and other potential applications for the patented processes will be described in the paper.

Jan 1, 1993

By P. R. La Pointe, H. C. Ganow

The production of both over- and undersized coal fragments is a constant problem to open pit operators in the Powder River Basin. Operators strive to achieve production blasts that economically minimize the weight percentage of over- and undersize coal. However, natural fractures influence blast fragmentation, and can impose limits on the final fragment size distribution. ARCO&apos;s Anaconda Minerals Company studied the limits placed by natural fracturing as part of a wider geotechnical study of the Wyodak Coal in the eastern Powder River Basin, Campbell County, Wyoming. Measurements of fracture orientation, size and spacing were made at ARCO&apos;s Black Thunder Mine. These data were used to form statistical distributions for natural fracture size, spacing and orientation. An algorithm was created to select fracture properties at random from these distributions and to form hypothetical blocks. The blocks were then numerically "sieved" to derive pos- sible particle size distribution curves. These curves are compared to fragmentation results from samples taken from three test blasts. All test blasts yield very similar lognormal fragment size distributions. The median particle size varies from 1.25 to 2.0 in.(3.2 to 5.1 cm), the mean from 4.0 to 8.5 in. (10.2 to 21.6 cm). The standard deviation was about 1.6 in. (4.2 cm). Coal fines (fragments < 0.25 in. or 0.64 cm) are about 15%. Calculated fragment distributions for the natural fractures predict the median size well but underestimate the variance. Algorithm modifications to account for processes known to occur in the comminution zone near the blast hole significantly improve the match in the fine coal size range. The match suggests that spacing of fractures, rather than fracture length, controls the formation of fine- and medium-sized fragments. On the other hand, the oversize coal is controlled by the fracture lengths, rather than the spacing. Data from subsequent test blasts support this idea. By increasing delay times from 8 msec to 17 msec, engineers were able to reduce fines to 7% - 10% but could achieve no further improvement, despite changes in shot pattern geometry, decking and hole size. The hypothetical fragment distributions show that, even without blast enhancement, about 5% of the natural coal blocks are fine-sized.

Jan 1, 1986

By R. R. Givler

Since the 1860&apos;s the good ole days, oil has been nozzle fed to burners under pressure atomizing the oil into droplets -- 1960&apos;s has produced vaporized oil that burns oil with the flame color and consistancy of gas -- If you can tell the difference by looking at the flame, gas or oil I?ll buy the lunch. First, we must ask, "Why all the excitement about Blue Flame?" This question is best answered by you after you have studied the principle of operation and see the result. I will attempt to explain both of these so that you can draw your own conclusions.

Jan 1, 1975

By Felicia F. Peng

Using a fuzzy logic controller, a signal applied on the processes may be generated through a linguistic protocol expressing an operator&apos;s intuitive control strategies. In this work, fuzzy logic controller and PID controller imposed upon the feedback liquid level control systems for a stirred tank are studied and compared. The construction factors including the shape of membership functions, number of fuzzy variables, number of inputs, number of rules, and different defuzzification methods are considered in design and formulating the fuzzy logic control strategies and algorithms. From the analysis of the strategies and control performances, an optimum controller may be generated by making use of the best combination of these fuzzy construction factors.

Jan 1, 1997

By Mahmoud Sepehrmanesh, Verya Nasri

The purpose of this paper is to outline the advantages and disadvantages of single tube and twin tubes for subway systems. Different aspects such as diameter of the tunnel (tunnel spaceproofing), configuration of subway line and stations, impacts on passenger safety and evacuation, ventilation system as well as rail system for each solution were evaluated and compared. In addition, a multi-criterion approach is established to facilitate the decision making for these two different subway systems. The practical example of a mega project has been discussed and the details of the decision-making process has been explained. This proposed multicriterion can be used to facilitate selecting the best subway system in any urban areas.

Dec 1, 2022