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By Jorma Miettunen, Reijo Kalapudas, Pertti Koivistoinen

A new method for measuring the mill filling was developed by Outokumpu’s Pyhäsalmi concentrator during 1989-90. The method utilizes the power draw oscillation which is caused by the mill lifters. Each lifter bar causes a peak in the power draw and thus a continuous oscillation results. In a fixed time scale, the oscillation peaks will shift as the lifter bare hit the mill charge sooner or later depending on the volumetric filling of the mill. Thus the measuring method is based on the phase shift of the power oscillation. So far the measurement is utilized for maximizing throughput of the primary mills at Pyhäsalmi and Enonkoski concentrators and at Harjavalta slag concentrator. The paper describes the new method and the results achieved.

Jan 1, 1992

By T. V. Vasudevan

Floc properties such as density, size, size distribution, porosity, and shear strength govern the effectiveness of flocculation as a process for solid-liquid separation. The floc characteristics desired for removal of suspended solids by sedimentation or filtration, for example, are known to he different. In this study, an attempt has been made to evaluate the effects of various physical and chemical factors on the density and shear strength of the flocs.

Jan 1, 1990

By A. Martikainen, S. GYAMFI

Luossavaara-Kiirunavaara Aktiebolag’s (LKAB) Konsuln iron ore mine, located just south of the famous Kiruna iron ore mine in Malmfälten in northern Sweden inside the Arctic Circle, was developed as a test mine between 2018 and 2020 for the Sustainable Underground Mining (SUM) project [1]. Besides functioning as a test mine, Konsuln also contributes to ore production. The existing mine ventilation system was designed for the current production rate of 0.8 Mtpa using conventional diesel machines. The design was created by Kiruna mine ventilation team, Stina Klemo and Joakim Jonasson, in cooperation with a consultant, Tomas Bolsöy from EOL Vent Mining AB. There is a plan to increase this rate to between 1.8 and 3 Mtpa in the future, and this requires the primary fans to be upgraded. Therefore, a study was carried out to determine whether using ventilation on demand (VOD) could avoid this fan upgrade and reduce Konsuln’s ventilation and heating power costs in the future. The study also investigated whether using battery electric vehicles (BEVs) along with VOD or as a standalone strategy could further reduce these power costs. In addition, the study analyzed the suitability of heating power reduction strategies presently or previously used in Nordic countries and Canada to investigate potential additional strategies to reduce heating power cost, the largest portion of Konsuln’s ventilation and heating power costs.

By J. Bigu

A theoretical radiation mine model, suitable for underground uranium nines, has been investigated. In this model, the rate of ventilation and/or the radon (thoron) gas emanation from mine walls are time-dependent. Several cases of practical interest have been investigated including sinusoidal, linear, exponential, stepwise, or a combination of two or more of the above. Analytical solutions were obtained for the time-dependent radon (thoron) gas emanation rate. However, because of the extreme analytical complexity of the solutions corresponding to the time-dependent ventilation rate case, numerical solutions were found using a special Runge-Kutta procedure and the Hamming's modified predictor-corrector method for the solution of linear initial-value problems. The mine model makes provisions for losses of radioactivity, other than by ventilation and radioactive decay, by, say, plate-out on mine walls, and by other mechanisms. Radioactivity data, i.e., radon, thoron, and their progeny. obtained with the above mine model for a number of ventilation and emanation conditions, are presented. Experimental data obtained in an inactive stope of an underground uranium mine for a time-dependent air flow case are shown. Air flow conditions (ventilation rate) were determined by tracer gas techniques using SF6.

Jan 1, 1987

By Fathi Habashi

THE UNIT process of adsorption involves two steps: 1) Loading of the adsorbent. 2) Recovery of metal values from the adsorbent. Charcoal is the adsorbent commonly used in extractive metallurgy. The discovery of the adsorptive power of charcoal from solutions is generally accredited to Lowitz (1785), who observed that several dissolved organic substances were precipitated on charcoal. Graham was the first to demonstrate that inorganic substances were also adsorbed on charcoal. In 1830, he reported that iodine dissolved in KI solution was adsorbed on charcoal. Also calcium ions were adsorbed from limewater, as were lead ions from lead nitrate solution. The use of charcoal in metallurgy was first applied

Jan 1, 1970

By G. Schriever, H. Thiel, E. J. Foell

A long-term, large-scale, disturbance-recolonization experiment with relevance to the environmental effects of deep seabed mining is described. The study is funded by the German government and was launched in the abyssal eastern tropical South Pacific Ocean in February-March, 1989. After obtaining pre-impact baseline environmental data, a 10.8 km2 (4.2 sq miles) circular area of seafloor was disturbed using a specially designed "plow-harrow" device. An initial post-impact sampling series was carried out immediately after disturbance followed by a second post-impact sampling series six months after the disturbance. Plans call for repeated visits to the site at two year intervals to monitor the anticipated slow recolonization process until the area is inhabited by a new, stabilized community.

Jan 1, 1993

By R. Hogg

Based on a simplified model for the motion of particulate materials in horizontal, rotating cylinders, approximate expressions have been derived relating the power consumption of a tumbling mill to its dimensions and speed of rotation and to the amount and nature of the charge. The basic assumptions underlying the model are that there is no slip between the charge and the mill shell, that the free surface of the charge remains essentially planar during rotation and that there is no transfer of momentum from the material flowing down the free surface back to the mill shell. The relationships formulated from this model have been shown to be in excellent agreement with experimental results taken from the literature. While the requirements of the model are most closer met at low speeds of rotation, the results appear to be valid even for speeds up to 70-80 percent of the critical speed. Poorer agreement between theory and experiment is found when the charge consists of relatively large particles (balls) and when the filling of the mill exceeds 50 percent of the available volume. Qualitative explanations of these deviations have been offered.

Jan 1, 1971

By J. Kemeny, B. Norton, T. W. BoBo

Digital image analysis systems to quantify particle size of crushed materials have successfully been applied in large-scale mining operations throughout the world. Particle size measurement at various crushing and sieving stages, especially in aggregate production, will facilitate the industry’s desire and need to achieve higher levels of process control and automation. This paper will 1) summarize applications of digital image analysis in the industrial minerals industries and introduce the Split-Online technology; 2) detail an actual recent test application of digital image analysis that ultimately lead to the installation of an automatic, non-invasive particle size distribution monitoring system; 3) document how this information is being applied: and 4) summarize the new Split-Online Aggregates Module now available.

Jan 1, 2004

By S. P. Lucido, I. Iwasaki

The potential of controlling heavy metal ions in effluents from discontinued mining operations and waste rock piles has been investigated. A fresh water green alga, Cyanidium caldarium, was found to have the potential to remove Cut' from solutions while exhibiting high tolerance to acid conditions which are commonly encountered in copper-nickel mine drainage. The process has the potential for application as a low maintenance metal decontamination system. The growth requirements and copper removal characteristics of this microorganism are described.

Jan 1, 1991

By C. Hilton

Arch Coal Inc. has implemented and sustained Best Practices at its four western mines through utilizing foremen in ongoing time studies. A prime benefit is the unique opportunity provided to front line supervisors. To date, 48 supervisors have participated in this program. Each quarter a new team is assembled with members from each operation. During three month blocks the supervisors conduct studies at each mine and identify best practices to implement at their own mine. Ongoing Best Practice and Action Item lists are reviewed each study. Mine management edits, prioritizes and monitors the completion of the proposed action items.

Jan 1, 2010

By Allan Rocas, Aswathy Sivaram, Daniel Cressman, Tatiana Chiesa

The City of Toronto plans to construct a 1,350 mm consolidation sewer along the East Don Roadway (EDR). The project includes installation of approximately 260 meter of 1,350 mm diameter concrete pressure pipe through microtunneling methods. The sewer alignment crosses underneath a busy 5-lane arterial road and then follows the very narrow East Don Roadway road allowance. This paper discusses the significant challenges overcome to design the Don Roadway sewer using slurry microtunneling methods through mixed face conditions below the groundwater table in a congested road allowance. A curved microtunnel was ultimately required to avoid conflicts with existing utilities, condominium tiebacks and a bridge structure.

Jun 13, 2023

By X. Wen, D. Tao, B. Li

A high effective method using a hammer mill, a column pneumatic separator and an electrostatic separator was studied for recycling copper from waste printed circuit board. The factors influencing the copper liberation degree and following separations were discussed. Two different physical separating methods were compared and discussed. Experiment results show that a well-controlled impact action can produce a satisfactory degree of copper liberation at a relatively coarse particle size. Around 90% copper recovery from printed circuit board for coarse particle size can be achieved by using a combination of electrostatic separation and pneumatic separation.

Jan 1, 2003

By John Marsden

JIM ARNOLD: Our next speaker is John Marsden. John runs the concentrator complex at La Candelaria Project in Chile. John's a Royal School of Mines graduate and he wrote the book on gold metallurgy, The Chemistry of Gold Extraction, which, by the way, he dedicated to me-at least that's what my copy says. [laughter] John, go ahead. (Message shown on Projection screen) ‘Raulerson’s Rules Plant operators and maintenance personnel should be asked to participate early in the design process. This ensures that the plant will never be completed on time or within budget.’ JOHN MARSDEN: Good afternoon, everybody. My presentation this afternoon is going to be very short. It won't be as funny as Joe Keane's, but I guarantee you it will be a lot quicker. [laughter] That transparency isn't mine, actually. [laughter] You're trying to throw me off.

Jan 1, 1998

By N. Magdalinovic

This paper analyzes the basic elements important for sustainable development in the sphere of metal mineral raw materials and offers one of the possible ways of defining the index of sustainable development.

Jan 1, 2007

By S. D. Thompson, L. Adler

Several researchers in the last 20 years have developed computer simulation models for designing coal mine belt systems. A careful review of these reveals that each omitted or oversimplified important factors, especially in belt loading. To remedy this, the coal mine belt capacity simulator (CMBCS) was developed to include various types of probability distributions, delays, and longwall and continuous haulage. CMBCS is computer coded in FORTRAN and employs the Monte Carlo simulation technique. Basically, the model simulates the loading and corresponding flow of coal through a belt system. By recording spillage and belt stoppage statistics for the simulated flow, belt and surge bin capacities can be evaluated. A complete user's guide is available. The modeling and verification of CMBCS are briefly described, and its major advantages and disadvantages are explored.

Jan 1, 1987

By Oren Tranbarger

The ability to sense or detect the coal/non-coal interface during mining can provide numerous advantages for improving net coal recovery and quality, for increasing productivity, and for mining coal which would otherwise be ignored. This is particularly true when considering multiple, pitching, and thin coal seams. This paper discusses the application of coal interface sensing and examines several potential coal interface sensing techniques with respect to state-of- the-art, design, performance, and cost criteria. Four interface boundaries are considered: the roof, the floor, the rib, and the forward region.

Jan 1, 1982

"What is your history and how did you get involved in mining?Like many SME members, I came from a mining community with a family history in mining, in my case Walkerville, MT. Both of my grandfathers were underground miners. My father was a miner for a short time. He later sold drinks to the miners. Unfathomable by today’s standards, my dad would pick up the miners’ checks at the pay office and have them cashed and waiting with a shot and beer for the miners when their shift ended. My mother was a nurse, who from time to time, would patch up an unfortunate miner. I remember walking past multiple picket lines on the way to and from grade school, watching homes being boarded-up. I grew up with a deep respect for the critical relationship between labor and management.I had no intention of going into mining and initially set out to pursue a career in chemical engineering. But I attended my first two years of engineering at Montana Tech, due to the proximity and affordability. This is where I met Dr. Tom Finch, a mining professor who taught statics to the engineering students. After a coaching session in a hallway, half way through my sophomore year, I switched to mineral processing engineering. In his colorful way, Professor Finch advised me that, “You do not want to make #@*!! erasers and #@*!! Jell-O the rest of your life go talk to the guys in mineral processing.” He was very persuasive and here I am today.How about your involvement with SME?I encountered SME out of school and a little later in my career. Terry Maio and Jim Arnold invited me to local section meetings in the Missouri Lead Belt. That was my first exposure to the technical programming and relationship building that was possible at the local level. After Ozark Lead shut down and I relocated to Nevada, Rich Johnson, Scott Barr and Dave Collins encouraged me to attend my first annual meeting in Salt Lake City, UT. I joined SME at that time and was fortunate to be engaged by members like Art Schweizer and Jim Arnold, and I soon began the leadership progression for the Mineral & Metallurgical Processing Division. Since then, I have supported SME at the national and the local level serving in multiple roles and capacities."

Mar 1, 2017

By J. A. Rose, A. S. Atkins

Environmental awareness has become a paramount consideration in the issue of planning and licensing arrangements for the disposal of wastes associated with mining operations. In this con- text the disposal of liquid tailings is a difficult and controversial problem with regard to environmental surface disposal. The paper outlines the use of Information Systems for decision support in the safe and environmental disposal of liquid tailings linked to conventional coarse refuse operations. This offers both an economic and an aesthetic approach to a historical perception of waste tipping in the underground coal extraction industry. The paper will demonstrate a prototype system that incorporates multimedia facilities which include data such as; voice comments, site photography, site plans and fluid flow circuits.

Jan 1, 1996

By Joseph A. Zupanick

Methane drainage is a mature technology, now commonly practiced in many highly productive underground coal mines throughout the world. Universally, the practice of pre-draining methane will continue to grow as near-surface coal seams become depleted and mining operations are forced to exploit deeper reserves. These deeper coal reserves inherently have higher gas contents. In addition, increases in productivity and extraction rates have caused higher methane liberations per unit of time. As the cost of providing ventilation air increases, the economic justification for implementing a methane drainage program becomes apparent.

Jan 1, 2005

By L. H. Munson, D. E. Hadlock, L. F. Munson, R. L. Gilchrist, P. D. Robinson

All uranium mills are required to perform sampling and analysis for radioactive particulates in their gaseous effluent streams and in the environment. Pacific Northwest Laboratory was requested by the U.S. Nuclear Regulatory Commission (NRC) to provide technical assistance to them for their Uranium Mill Health Physics Appraisal Program. In conducting appraisals, air sampling methods used at NRC-licensed mills were reviewed and several deficiencies noted. This paper includes only environmental and effluent particulate sampling although much of the information is applicable to both in-plant and environmental samples. First, the components of a proper sampling program are discussed: program objectives, program design, sampler design, analyses, quality assurance, and data handling. Then the specific deficiencies, or the "pitfalls" from the first 8 mill appraisals are discussed. The first consideration in establishing an air sampling program is defining the objectives of the program. What is air sampling suppose to accomplish? Many of the deficiencies we have observed have resulted because the desired objectives were not clearly established in the minds of the radiation safety staff. PROGRAM OBJECTIVES An environmental air sampling program ought to fulfill the following seven objectives. The first is to: 1) [demonstrate regulatory compliance]. Although a goal of most programs, regulatory compliance, is not well understood. One has not only to comply with the conditions of the source materials licensee, but one must also demonstrate compliance with 10CFR20 and 40CFR190. For example, 10CFR20.106 states: "A licensee shall not possess, use, or transfer licensed material so as to release to an unrestricted area radioactive material in concentrations which exceed the limits specified in Appendix B, Table II of this part .... For purposes of this section, concentrations may be averaged over a period not greater than one year." Even if a mill's license does not require sampling at the site boundary of maximum concentration, a sample may be necessary to demonstrate compliance with 10CFR20. Most mill personnel are painfully familiar with 40CFRl90.10, which states: "Operations.... shall be conducted in such a manner as to provide reasonable assurance that: (a) The annual dose equivalent does not exceed 25 millirems to the whole body.... of any member of the public as the result of exposures to planned discharges of radioactive materials, radon and its daughters excepted... from uranium fuel cycle operations..." This means a licensee's sampling program must give "reasonable assurance" that the member of the general public receiving in the most exposure gets no more than 25 millirems per year. The sampling program necessary to provide that assurance may or may not be a license requirement. However, merely meeting the license requirements and the explicit regulatory requirements does not necessariarly ensure an adequate effluent and environmental air sampling program. The second objective of the environmental air sampling program, is to 2) [identify the source(s) of contaminants]. This will include not only the routine program, but special sampling for verification of sources and nonsources. Only after sampling can a mill operator be assured that roof vents, laboratory hoods, and other localized ventilation systems are not making a significant contribution to environmental releases. An environmental sampling program should also allow the mill operator to fulfill the third objective, to 3) [estimate exposures]. Even before 40CFR190, a sampling program should have provided the mill operator with the information necessary to determine the dose to the "fence post" person, or at least to determine if doses were well below the 10CFR20 limits previously allowed. The program should 4) [detect and measure unplanned releases]. If there is a fire, a scrubber failure, or if a drum of yellowcake breaks open, measured releases will almost always be lower than conservative estimates. Whether or not a system to provide sampling during accidents is needed is almost always a cost-benefit decision. In general, uranium operations do not sample just in case an accident may occur. Yet they may decide on continuous air sampling in lieu of intermittant sampling partially because of the potential for accidents. Another objective of air sampling is 5) [to provide information on the effectiveness of control systems]. This is always a concern with new or modified equipment and may dictate sampling frequency in other situations as well. For instance, if a small leak in a bag filter cannot be detected by other means, then more frequent stack sampling may be indicated. A routine effluent and environmental monitoring program should also fulfill the sixth objective,

Jan 1, 1981