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By R. D. Coursen

Tin has been one of the very few commodities which has been covered by an international commodity agreement. It is the only metal so covered. The reason behind tin's prediliction for an agreement has been the inconsistency of the price pattern for tin during the entire 20th century. It is not surprising in view - of the wide and wild fluctuations in its price that tin has been called the Cinderella metal. An examination, for example, of prices in 1977 alone attests to the erratic behavior of the tin markets. The high was recorded on October 27 at M$1,895 per picul and the low on January 3 at M$l,314 3/8, on the Penang market, a spread in Malaysian dollars of $581 for a picul weighing 133 1/3 pounds. The first steps in international cooperation on tin were taken after the price bonanza of the First World War. Despite a lack of increased consumption, and in spite of the fact there was no shortage of mining production during the war, prices boomed. Shipping shortages and thinning stocks brought about a situation where in the U.S., industrial stocks were only 1/6 of what they had been in 1914. The boom busted early. In 1921 the tinplate industry of the world had cut its output in half and total world consumption of tin fell by 1/3. Tin producers became so concerned that they created what was called the Bandoeng Pool. It accumulated stocks held by countries now known as Indonesia and Malaysia, amounting to 28 percent of the combined production of the two countries and about 15 percent of the total world for 1921. The pool holdings were shortly exhausted and thereafter in the years 1924 to 1928, general boom conditions existed for tin.

Jan 1, 1978

By E. M. R. Santos

Acid mine drainage (AMD) is a serious environmental problem in mining activities. Prediction is the first step for evaluate the potential of acid generation and there are some possible methods to estimate it. They are described as static tests, which examine the balance between acid producing and acid consuming materials, and kinetic tests, which attempt to predict drainage quality over time. Static methods are very simple and give a qualitative classification of the ores based on their potential to generate acid drainage. The characterization of ores to determine their acid producing potential is vital for the prevention of long term environmental liabilities. Laboratory tests were conducted under different methodologies to predict the acid producing potential of sulphide overburden, ore materials and tailings from a deposit of copper ore.

Jan 1, 1999

By Arman Hazrathosseini, Ali Moradi Afrapoli

Fleet management systems (FMSs), as a pivotal part of any surface mining operation, need to evolve from conventional to intelligent systems because of both Mining 4.0 requirements and some shortcomings inherent in conventional methods. However, this novel transformation needs to be investigated technically and strategically. To this end, previously published research works on intelligent FMSs are explored to track the latest status of these third-generation frameworks within the surface mining context. Their underlying models are then compared in terms of five categories of allocation and dispatching features to pinpoint the technical gaps ignored. Having drawn the future lines of research, the present work then leverages the popular SWOT analysis method to outline the strengths, weaknesses, opportunities, and threats associated with the advent of these intelligent FMSs in mines of future. By and large, the analysis indicates that advantages outweigh disadvantages. Solutions are offered to address the existing weaknesses and threats.

Apr 1, 2024

By Alphonse C. Van Besien

It is doubtful if anyone knows precisely how many U.S. coal miners have been killed by roof falls. In 1931, 51 miners were killed by falls or rock in every 10-day period (Paul, 1). Roley (2) indicated that from 1882 to 1945, over 3,700 men were killed by roof falls in Illinois alone. During this 63-year period, roof falls accounted for 47.6 percent of the coal mine accident fatalities. Similarly, Price and Nolting (3) reported that during the 10-year period beginning in 1937, roof falls claimed over 50 percent of the lives lost in West Virginia coal mines. Over 150 miners died under fallen rock in West Virginia alone, in each of those years. Certainly, the statistics have improved over the years. The Theodore Barry Report of 1971 (4) indicated that during, the previous 4 years, fewer than 100 miners per year lost their lives to roof falls--in the entire United States. The improvement is less remarkable when it is realized that the accident rate has declined only as the number of miners employed underground has declined. The TRW Report (4) pointed out that although the number of fatalities in underground coal mining (from all causes) had been cut in half from 1956 to 1965, the fatality rate per thousand miners had remained virtually constant. The decreased accident rate was due not to a reduction in hazards but to a reduction in work force. Roof falls still claim approximately 50 percent of the lives lost in underground coal mines. Considering the increased underground production of coal which must result from our energy crisis, the environmentalists' pressure against strip mining, and our inevitably diminishing supply of strippable coal, it is apparent that some means must be found to reduce the number of lives claimed by coal mine roof falls.

Jan 1, 1973

By Arthur P. Nelson

In opening, I want to thank the program committee and members of the Society of Mining Engineers of AIME for the opportunity to speak to you. Various chapters of AIME this past year have expressed interest in the Federal Metal and Nonmetallic Mine Safety Act. We want to see that interest continue, because the reason for the legislation was the safety and health of the industry's workforce. The Department of the Interior was directed by the Congress to administer the provisions of the Act and is therefore held directly accountable for the success or failure of its intent. We intend to see it succeed. Among other things, the Act does provide for education and training under Section 15. This provision has been implemented and is expanding. However, the responsibility of my office is inspection and enforcement and that is my subject today.

Jan 1, 1973

By CHENCHEN SUN, GUOPING LUO, GUOCHENG ZHANG

In this study, the conditions of raw materials and fuels were simulated for Bayan Obo iron ore concentrate by adding pure calcium fluoride (CaF2) in various concentrations to Australian iron ore. The mechanism by which the fluorine (F) content of the lattice influenced the reduction swelling properties of the iron ore briquettes during various stages of the reduction process was investigated. The results provide insight into the mechanism governing the reduction swelling process in Bayan Obo ore briquettes, which could be used to direct real?world production practices, particularly those related to the rational utilization of Bayan Obo ore resources.

By ERIK CHARRIER, ADITYA JUGANDA, Jürgen Brune, Gregory Bogin, Patrick Maier

Confined explosions are a major risk in underground coal mine operations. Depending on confinement, ignition location and obstacles in the flame path, methane explosions can transition to detonations. This research focuses on explosion experiments in a reactor with diameter of 71 cm and length of 30.5 m, along with developing the corresponding computational fluid dynamics (CFD) model that captures the observed flame behavior. The results show that the 2D and 3D CFD models are able predict the experimental flame front propagation velocity, but the 3D model shows more explicit conformity than the 2D model.

May 1, 2024

By NARAYAN K. BHAGAT, ARVIND K. MISHRA, Aditya Rana, M. M. Singh

The paper presents an innovative directional controlled blasting (DCB) technique for excavating unstable slopes along the Konkan railway in India without disturbing the traffic. New empirical formulae for small geometry blasting to estimate burden and throw were 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 was changed from 80–82 to 45–47 degrees, and possible wedge, planar and toppling failures were eliminated. No incident of rockfall and slope failure along these slopes has been observed after the stabilization.

By Adrianus Halim, Jenni Hooli, Bartłomiej Skawina, Fredrik Sundqvist

Transitioning from diesel-powered loading and hauling machinery to battery-electric vehicles (BEVs) responds to the need for deepening underground mines as regulations become tighter. When using BEVs, exhaust gases and diesel particulate matter (DPM) emissions can be eliminated, and the energy required for the machines is used more effectively. Unlike their diesel counterparts, which are refueled, BEV loading and hauling machines — specifically, load haul dump (LHD) machines — can use battery swapping. This brings additional aspects to the operation that need to be considered, which have not yet been studied extensively. This study used discrete event simulation (DES) to analyze how the different numbers of BEV LHDs affect queueing and productivity when using different numbers of batteries and different swapping times in an underground block cave mine. The results identified the formation of working groups, where the machines swapped their batteries concurrently within each group, and their relation to the queueing time. Additionally, the minimum number of batteries per machine was identified to maximize productivity while minimizing queueing time. This study demonstrates DES as a powerful tool to assess and analyze conceptual systems and identify their underlying structures, which can enhance the deployment of BEV LHDs in underground block cave mine operations.

Apr 1, 2025

By M. C. Williams

As the flaws in the population balance model (PBM) comminution model are examined more deeply, further errors and problems were discovered. The Levenberg-Marquardt algorithm for systems of constrained non-linear equations was used to solve the dynamic PBM grinding equations to obtain the grinding selection and breakage rate functions. The fact that the PBM model equation Inverse Problem is degenerate or underspecified is demonstrated. Multiple solutions to the same PBM equations are provided. It is shown that there is no unique solution to the Inverse Problem unless additional constraints are provided or assumptions are made such as the Arbiter-Bhrany normalization assumption. The severity of the non-uniqueness problem for dynamic grinding is demonstrated. Each solution to a dynamic PBM, while giving the same prediction for a given grinding time interval, gives different solutions or predictions for mill composition for other grinding times. Actual experimental grinding data was assessed to determine the functionality of mill selection and breakage functions.

Jan 1, 1993

By H. G. Schoenike

A subsequent spin off of the energy shortage is the new life for barite. Over 90% of the barite produced in the world is used as a weighting material in oil well drilling muds. Business is booming; the price of barite has risen; scarcity is imminent, and exploration is going full steam ahead. New barite-producing companies are being formed and many of the barite consumers are considering becoming producers. Prospectors have found a new "love," smaller deposits are being explored, and old deposits, previously rejected, are getting a reappraisal. Even barite tailing piles are being resampled.

Jan 1, 1980

By W. C. Shanks

The Pioche District of Lincoln County in southeastern Nevada (Figures 1 and 2) has been an historically important producer of silver, zinc, and lead. Economic geology of districts in the Pioche area is summarized most adequately in recent reports by Tschanz and Pampeyan (1) and Gemmill (2) and only a few major aspects will be discussed here. Production in the Pioche District began in 1869 and early mining concentrated on silver-bearing fissures in lower Cambrian quartzites. In the early 1870's the Pioche District was second only to the Comstock Lode in world silver production (3). More recent mining activities have centered on the other major ore type in the area, bedded replacement of lower Cambrian carbonates by Ag-Zn-Pb sulfide ore. Production of replacement ore peaked around 1950. The present study is focused on the Pan American Mine because it is an excellent example of low grade carbonate replacement deposits, because there is little structural dismemberment, and because access was readily available. Most previous workers have suggested that both the fissure vein deposits and the bedded replacement deposits of the Pioche districts are a result of spatially related Laramide igneous activity. The purpose of this study is to determine whether ore genesis is a result of igneous activity or if mineralization might be related to late diagenetic processes such as formed Mississippi Valley "type" deposits. Stable isotopes of sulfur, carbon, and oxygen in ore and gangue minerals have been studied to determine the probable isotopic composition of the ore fluid and paleomagnetic studies of the carbonate rocks have been utilized to determine timing of mineralization. Additionally, petrographic and field studies of carbonate lithologies were undertaken in an attempt to delineate non-structural controls on ore localization. These studies are still proceeding and the results presented herein are, therefore, preliminary in nature.

Jan 1, 1979

By Robert W. Bartlett

Both hydrometallurgical and vapometallurgical processes often involve ores that have been previously ground and size classified. When the valuable mineral is substantially liberated, the chemical reaction is likely to occur on the particle surface and the particle core will shrink as the reaction proceeds. If the chemical reaction products are solid materials then a solid shell, usually porous, will form around the shrinking core. This is known as the core/shell or topochemical reaction model. Using a spherical approximation for the particles, equations have been developed to express the extent of chemical conversion of the particle, depending on which one of the following process or mass transport steps is rate controlling:1 (1) chemical reaction at the particle surface, (2) diffusion through the thickening reaction product shell or (3) mass transport through a boundary layer surrounding the particle. In a previous paper2 these equations were coupled with the Gates -Gaudin-Schuhmann equation 3 4 describing the distribution of particle sizes resulting from comminution of rocks and other brittle solids to develop reaction yield curves expressing the weight fraction of metal or other valuable component of the feed that was chemically converted as a function of residence time. This was done for (a) batch, (b) continuous plug flow and (c) continuous back-mix flow (continuous stirred tank) reactors or process vessels. To make the curves of general rather than special utility, the residence time (average residence time for back-mix reactors) was normalized to a dimensionless time by dividing by the time required to completely chemically convert the largest particle in the feed to reac-

Jan 1, 1972

By Anthony W. Garson

Good morning, ladies and gentlemen: It is a pleasure to be here this morning as a representative of Dean Witter Reynolds; one of the foremost international investment firms in North America. My colleague, Hugh Wilmer (who will be speaking to you a little later), and I are involved as research analysts in the research and writing of published reports containing recommendations on the buying or selling of North American and South African gold and silver mining shares. Our talk this morning will focus on the gold mining operating costs of North American and South African gold producers. However, I am not going to bore you with reams of statistics on the operating costs of large numbers of gold mining operations; how meaningful would this data be to you? Instead, I will discuss what the investor should look for, and how he should use this knowledge in making his investment decision.

Jan 1, 1984

By L. Yuan, J. H. Rowland, R. A. Thomas

Hydrogen (H2 ) gas released during battery charging can result in cross-interference for carbon monoxide (CO) sensors used for early fire detection and compromise the integrity of the mine atmospheric monitoring system. In this study, a series of laboratory-scale and full-scale experiments were conducted to evaluate the responses of different CO sensors to H2 gas. In the laboratory-scale experiments, H2 concentrations in the airflow are constant, while in the full-scale experiments, increasing H2 concentrations generated as a byproduct of charging the batteries at the battery charging station rise to the sensors under different ventilation scenarios. The H2 concentrations at the CO sensor location were measured using H2 sensors and were correlated with the CO sensor response. The effects of ventilation and sensor location on the CO sensors responses were also analyzed. The results of this study can help mining companies to select appropriate CO sensors and improve the deployment of these sensors to safeguard underground miners.

By John S. Summer

The induced polarization (IP) method of geophysical exploration is capable of detecting even small amounts of metallic luster minerals in a rock mass. Consequently, in the years since discovery, IP surveying has become the most popular ground geophysical survey method. It is not too difficult to understand many applications of IP surveying as used in the search for mineral deposits. However, the basic theory of the IP phenomenon is not well developed or understood, and there has been some disagreement on fundamental concepts. In order to most effectively apply the IP method in the field it is necessary to know the physical characteristics of the sought-for deposit including its size, shape, depth, and electrical properties. With this information an optimum IP search arrangement can be devised and one could use the best possible electrode interval, type of array, and line spacing. With uncertain target characteristics as encountered in the real world, geological guidance must be used to help direct an optimized IP survey.

Jan 1, 1972

By Martin J. Hughes

The Eagle Mountain Mine of the Kaiser Steel Corporation is located in the California portion of the Colorado Desert at a distance of about 60 miles east of Indio, California. At the present time, this mine is producing at the rate of 5,000,000 tons of concentrate per year. A total of 1,000,000 tons of ore per year is presently being sold on the Japanese market while the remainder is consumed by the Kaiser Steel Company blast furnaces at Fontana, California. A new Pellet Plant and Concentrator is presently under, construction with completion scheduled for May or June 1965. This plant will have a rated capacity of 2,200,000 tons of pellets per year and essentially all of this production will be sold to Japanese steel companies.

Jan 1, 1965

By Brendan Demich, MAHIYAR F. NASARWANJI, Alan G. Mayton

During dusk, nighttime and dawn operations, effective illumination is a crucial component of safety for getting on/off mobile surface mining equipment and for preshift inspections. U.S. National Institute for Occupational Safety and Health (NIOSH) researchers examined whether illuminance levels could be improved for ingress/egress systems and preshift walkaround inspections of equipment using light-emitting diode (LED) area luminaires. Illumination and glare were key metrics evaluated. Although headlamps provided adequate illumination, LED area luminaires illuminated a much broader area compared to the narrow spot lighting of the headlamp. Hence, the use of additional area luminaires can increase slip-trip-fall (STF) hazard awareness and detection. Furthermore, a commercially available luminaire demonstrated better results than a custom LED luminaire relative to discomfort and disability glare.

By H. Y. Sohn

The paper discusses two processes, flash ironmaking technology (FIT) and moving-bed ironmaking technology (MBIT), which aim to reduce energy consumption and greenhouse gas emissions in the ironmaking industry by using concentrate directly without pelletizing and without using coke.

Aug 1, 2023

By Joel Lööw, Jan Johansson, Lena Abrahamsson

In this study, we try to illustrate what new technology can mean for the individual miner. We formulate the notion of Mining 4.0, where we attempt to create an image of how the future might look from a miner’s perspective and how mining companies might navigate their way to a future that works for all miners.