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By L. M. Kocher, J. R. Heberger, J. P. Pollard, M. F. Nasarwanji

Injuries associated with hands and fingers are highly prevalent in mining and identifying factors associated with these injuries are critical in developing prevention efforts. This study identifies nonfatal injury incidence rates, nature of injury, work activities, glove usage, and sources of hand and finger injuries in the U.S. mining industry, as reported to the Mine Safety and Health Administration (MSHA) from 2011–2017. Hand and finger injuries occur at a rate of 6.53 per 1,000 full-time employees, which is nearly double the rate of the next highest affected body part, the back. Most of the hand and finger injuries were classified as cuts/lacerations/punctures (53%) followed by bone fractures/chips (26%). Materials handling and maintenance/repair were common activities at the time of the incident with miscellaneous metals (pipe, wire, guards) and hand tools as the primary sources of hand and finger injury. Although information on glove use was limited, leather gloves were most often worn when an injury occurred. When worn, gloves were found to contribute to 20% of the injuries, indicating their potential to protect the hands, but also potentially put the hands at risk. Further research is necessary to determine performance requirements for gloves used in mining operations, specifically those offering cut and puncture resistance.

Mar 2, 2022

By Charlotte Abena Benyarku, Albert Buabeng, Eric Stemn

The abstract highlights the increasing use of mobile equipment in mining and its contribution to accidents. The research analyzes injury narratives from Ghanaian surface gold mines to understand the involvement of mobile mining equipment in injuries and explore the use of injury narrative data as a human factors tool. The study identified priority human factor issues, such as operating mobile mining equipment, part removal/installation, and the operator's cabin. The use of Sankey diagrams for multivariable analysis effectively identified specific operator-centered issues that warrant further investigation for improved safety interventions.

Mar 29, 2022

"The profile of the respondents was that of a professional responsible for communications, community relations or corporate social responsibility programs. By targeting a consistent professional profile it was possible to ensure that most respondents had a similar degree of responsibility and/or decision-making ability related to the application of communication technologies. The research attempted to be inclusive and attention was paid to interview respondents from both genders and from indigenous groups.4, 5 A codebook of 80 themes was developed that highlighted recurring topics; for example, codes were created to identify risks, benefits, policies and learning process of using social media and included topics that were repeatedly emphasized by respondents (i.e. age, efficiency and language). Both manifest coding (i.e. coding of the visible content, such as specific words) and latent coding (i.e. coding of underlying meanings) was undertaken (Creswell [13]). The codes were used in the qualitative analysis using ATLAS.ti software and network views were created to illustrate the relationship between major themes of this research. There are limitations to this research, largely related to the changing nature of the Internet and communication technologies. There is also a geographic limitation to the application of this research because most of the data was gathered primarily from Canadian sources.6 Different levels of Internet penetration, or limited access to computers or mobile devices, and low literacy rates may reduce the applicability of the research in countries with low Internet penetration. A more systematic process to selecting candidates may have helped bring balance to the final list of interview respondents. For example, most of the corporate respondents were from medium and large companies and there was not adequate representation of small mineral exploration companies. The research did not probe into social media applications by different business groups within the mining sector, such as smelting and processing."

Jan 1, 2011

By P. Sarnoff

Gold has always been a crisis investment. For centuries gold has been considered globally the money of last resort. In time of war, inflation, financial uncertainty, political upheaval there has with few exceptions always been a flight to gold. The gold paradox simply is that even though we have gone through for the past handful of years all the kinds of. anxieties that would cause the gold price to rise, it has instead dropped drastically. Figure 1. illustrates the important factors that influenced the gold price significantly up or down before 1987. Obviously, since then, even though we have had wars, inflation, financial problems involving breaking banks and thrifts let alone collapsing financial institutions, the gold price has both in the long-term and the short-term trended downwards. Figure 2. depicts the gold price path since 1987. If the presence of time-honored and time-tested factors that should have driven the gold price up didn't do the job, then logic dictates that new factors to drive the gold price down and keep it depressed arose. And they did. But before addressing these depressants permit me to turn to the arcane art of gold price prediction and fore-casting.

Jan 1, 1992

By Robert S. Holmes

The U. S. Army Corps of Engineers Explosive Excavation Research Office (EERO) of Livermore, California, has been engaged in research and development of excavation techniques using both nuclear and conventional explosives since 1962. Prior to July 1971, this organization was designated the U. S. Army Corps of Engineers Nuclear Cratering Group. The EERO mission is performed as part of the joint Atomic Energy Commission -Corps of Engineers nuclear excavation research pro-gram. During the period 1962-1969, the Corps executed many cratering explosions using spherical charges of up to 85 tons of nitromethane to model nuclear excavation concepts and to develop design criteria for the nuclear cratering explosions. The experience gained in these modeling tests suggested that explosive excavation using large chemical explosive charges could be applied to excavation projects as an economical substitute for traditional excavation techniques. Consequently, the Corps' research program was broadened in 1969 to include development of chemical explosive excavation as a construction tool. The term "explosive excavation" denotes the use of large buried explosive charges to produce an excavation by fracturing the material and casting it into a desired configuration. In its simplest form, this technology involves detonation of a single explosive charge buried at the proper depth to produce a crater which is roughly hyperbolic in cross section. The types of craters produced by various depths of burial are illustrated by Figure 1. Single or Multiple rows of charges are used to excavate linear cuts required for water conveyance or navigation channels. .More complex explosive excavations include small craft harbors, railroad and highway cuts, and removal of W1denvater rock barriers to navigation. While the literature indicates widespread use of large explosions in the (1) ERRO is a field activity of the Waterway Experiment Station, Vicksburg, Mississippi

Jan 1, 1971

By Nilufer Kursunoglu

Despite being crucial for meeting the world’s energy demands, coal mining operations present considerable health risks, especially when it comes to exposure to coal dust. Longwall coal mining, an advanced technique, has considerably enhanced production but made dust control more difficult. Due to its explosive nature, coal dust continues to be a serious and dangerous concern in the industry despite developments in safety technology. This study aims to comprehensively assess the risk of coal dust explosions by integrating fuzzy risk matrix and Pareto analysis methodologies, offering precise risk ratings for various root causes. A fuzzy risk matrix was developed to assign exact risk ratings to identified root causes. Additionally, a Pareto chart was used to identify the main reasons and suggest particular preventive measures. 17 significant causes were determined for underground coal mines based on the study’s methodology, and some preventive measures were suggested. In accordance with fuzzy risk rating values, root causes were divided into six categories. The root hazard with the highest risk rating was identified as ‘accumulation of inflammable gas/gases’. The proposed approach was used to examine incidents caused by coal dust explosions in Turkish coal mines in order to demonstrate the effectiveness of combining the fuzzy risk matrix and Pareto analysis for assessing coal dust explosions. This study gives not only a solid framework for risk assessment but also critical information for classifying the risks associated with coal mine dust explosions. The results highlight the critical necessity for proactive and preventive actions to reduce the hazards of coal dust explosions and protect the safety of mining workers.

Nov 16, 2023

By N. K. Dumakor-Dupey, G. B. Sakyi-Addo, K. J. Bansah

"Artisanal and small-scale mining (ASM) occurs in many countries around the world, and provides a source of livelihood to many impoverished local people in areas where it occurs. This paper reports the role of female participants and reasons why they engage in ASM. Field visits were made to 12 ASM sites located in the Tarkwa Mining District of Ghana to conduct interviews with male diggers and female participants. It was observed that over 100 women between the ages of 18 and 50 participate in ASM for survival. They engage in ASM largely because they have no alternative employable skills and income sources. These female participants depend on ASM to sustain the lives of their dependents. INTRODUCTION Artisanal and small-scale mining (ASM) conventionally involves use of rudimentary tools (such as picks, shovels, chisels and hammers) to exploit precious minerals and metals from the ground. It has been a major source of livelihood to many impoverished local people for more than a century. In many instances, it is the only source of income to indigenous people who have no alternative employable skills. The World Bank estimated that more than 100 million people around the world benefit from ASM which largely occurs in developing countries in Asia, Africa, Oceania, and South and Central America (World Bank, 2013). Cobalt, which is used in lithium-ion batteries to power cellphones, laptop computers, and electric vehicles, is largely produced by artisanal miners in Congo (The Washington Post, 2016). In Sudan, ASM is a significant contributor to the national economy, accounting for about 85% of total gold extracted yearly from 2010 to 2015 (Ibrahim, 2015). Also, according to the Embassy of Sierra Leone in Washington DC, USA, 90% of mineral export in Sierra Leone can be attributed to thriving artisanal diamond mining in the country (Sierra Leone Embassy, 2016). In Ghana, the ASM sector was recognized by government as a multimillion industrial activity, and through a series of initiatives, it was legalized by promulgating the Small Scale Gold Mining Law of 1989 (PNDCL 218). Presently, artisanal mining is widely practiced in two forms: licensed (registered), sometimes referred to as formal ASM, and unregistered (informal or illegal) operations, popularly called “galamsey”, a name believed to have been derived from “gather and sell” by ancient miners who could not communicate in the English language with European/British miners. The ASM sector in Ghana, like other countries, has seen a rise in female participation over the years. A report by the International Labour Organization (ILO) indicated that women account for about 15% of total workforce in ASM in Ghana, and up to 50% in Africa (ILO, 1999). Other researchers have also estimated women participants in ASM to be between 30 and 70% in Africa (Hinton et al., 2003a; Hinton et al. 2003b; Hilson, 2002). Presently, there is no reliable data from Ghanaian authorities on number of females engaged in ASM. However, data obtained from 15 ASM sites suggest that at least 40% of the employees are women. It is expected that a similar trend exists across ASM operations in Ghana."

Jan 1, 2017

By C. D. Anderson

A variety of processing technologies exist for recovery from both primary and secondary sources of rhenium. Currently, there are no known primary rhenium deposits; thus, the method in which primary rhenium is produced is dependent on the commodity of which it is a byproduct, e.g., copper, molybdenum, uranium, etc. In addition, focus on the recovery of rhenium from secondary sources, such as alloy scraps and catalysts, is continually growing. This paper presents a review of both primary and secondary processing technologies for the recovery of rhenium.

By P. Amelunxen

This paper presents the authors? personal experiences in the design and operation of moly separation circuits in copper-moly concentrators. Topics discussed include column cells versus mechanical cells; use of nitrogen; use of CO2 and sulfuric acid for pH modification; and general equipment selection and sizing. A benchmarking of main operating parameters for industrial plants is presented. Upgrading curves for commercial column and mechanical cleaning circuits are also presented, showing that with average flotation kinetics and rougher concentrate grades, technical grade concentrates can be easily achieved with five column cells operating in counter-current configuration.

Jan 1, 2009

By S. S. Peng

High horizontal stress has been well recognized as a significant factor in roof control. It can adversely affect roof stability if the panel is designed improperly. Mining experience has shown that it can cause a cutter roof. The effects of high horizontal stress on roof stability depend on many factors such as magnitude and direction of the maximum principal horizontal stress, ratio of the maximum to minimum principal horizontal stress, structure and mechanical properties of the immediate roof and mining sequence. However, little is known about the intrinsic mechanism of high horizontal stress effect on roof stability except some conceptual explanations. In order to design a stable entry, the redistribution and concentration of high horizontal stress around the openings must be fully understood. Using the 3-D finite element analysis technique, this paper presents the redistribution and concentration of high horizontal stress field for a three-entry system with different orientations of horizontal stress. Based on the horizontal stress redistribution, possible roof failure for different orientations of horizontal stress is analyzed.

Jan 1, 1996

By Robert C. Pease

Siskon Gold has started gold production at the San Juan deposit in northern California. The mine is located about 27 km (17 miles) north of Nevada City, CA (Fig. 1). It is scheduled to be-come the largest underground gold mine in California. It is situated in the western foothills of the Sierra Nevada Mountains in the Mother Lode gold belt. The property consists of 8 km2 (2,000 acres) of patented land. It is situated in a topographically high area known as San Juan Ridge, which is 213 m (700 ft) above and between the Middle Yuba and South Yuba rivers. The elevation is between 790 and 914 m (2,600 and 3,000ft) above sea level. Annual precipitation averages 1,346mm (53 in.). Most of that falls between November and April.

Jan 1, 1996

By Thomas J. Lien

Granitic Pegmatite deposits are the chief source of commercial feldspar, micas, lithium minerals, tantalum-columbium, beryl, and certain types of kaolin. The output from pegmatite mines in the United States is small compared to other mineral products in terms of bulk or value, and much of it comprises only minor metals and nonmetals. Nevertheless, pegmatite minerals play a vital part in our domestic industrial economy, particularly in the ceramic and electrical industries. Numerous special purpose uses also are important, even though they require small quantities of raw materials. In recent years, realizing the potential importance of the pegmatite minerals, the U.S. Geological Survey, the United States Bureau of Mines, several state Bureaus of Mines, and a few private companies have carried on extensive programs of pegmatite studies in the New England and southeastern states, in the Black Hills area of South Dakota, in the Rocky Mountain region of Wyoming, Colorado, and New Mexico, and in various parts of Washington, Idaho, Utah, Nevada, Arizona, and California. Currently, some of the pegmatite minerals such as micas and spodumene are selectively separated by the flotation process. To a lesser extent a few plants are selectively floating feldspar and quartz. Much of the credit for the above progress goes to the fine work done by U.S. Bureau of Mines (1), and companies such as Foote Minerals (2). Additional research efforts by the New Mexico Bureau of Mines (3) has successfully demonstrated selective separation of micas, beryl, spodumene, lepidolite, microlite, quartz and feldspar from a complex Pegmatite containing all these minerals. Since the nature of the mineralization of various valuable components of a pegmatite deposit is such that selective separation of some of these can be carried out at a coarse size using the Heavy Media Separation technique, it was felt that such a system should be investigated for selective preconcentration of their minerals. It was also felt that of all the :MS systems available, the DYNA WHIRLPOOL (DWP) device which allows a close control and adjustment of specific gravity should provide a means of achieving the above goal. Once the desired preconcentration of one or more of the pegmatite mineral assemblage is achieved, the available selective flotation techniques should provide effective recovery of various minerals into marketable products. This paper presents technical and economic aspects of selective preconcentration of some of the pegmatite minerals followed by selective flotation to produce marketable products.

Jan 1, 1978

By T. J. Haddon

For the mining industry in general and gold mining in particular the past few years have been difficult. Economic conditions coupled with growing regulatory restrictions have led to increasingly important reasons for managing assets wisely. From a public company perspective this makes sense because it ultimately provides for an increase in shareholder wealth and that's what we're in business to do. Regardless of whether a company is public or not, assets must be managed effectively to remain a player in today's competitive environment. So, as the CEO of a gold mining company, how do we manage our assets to ensure that we are satisfying our obligations to our customer --the Amax: Gold shareholder? Let me tell you. As I said earlier, the gold industry has been under siege. We have just completed our third year of average prices below $400 per ounce. When you add finding and/ or acquisition costs and development costs to operating costs, there isn't much of a profit margin left. What this environment provides, however, is opportunities for growth. In the gold business, you either grow or you die. Today, most North American gold producers have at most a 10 year mine life. We are all scrambling to add reserves so we don't become extinct. As prices remain low, opportunities for increasing diminishing reserves abound. This is the time for the opportunistic company to take advantages of market conditions and that's precisely what we, at Amax: Gold, have done!

Jan 1, 1992

By RICKARD HANSEN

With vehicles frequently found in underground mines and tyres being a major fuel item, the risk of tyre fires will be severe underground. This study presents an in-depth analysis of tyre fires on mining vehicles to increase the knowledge of the risk, applying data from full-scale fire experiments and CFD simulations. It was found that the wheelhouse of the loader caused an increase in the flame tilt angle of approximately 10%, decreasing the flame impingement and heat flux downstream. The flame temperature of the drilling rig tyre was found to be approximately 7% higher than the loader tyre, increasing the risk of igniting adjacent fuel items. The construction of the wheelhouse/mudguard will contribute to a longer flame length by creating a fuel-rich environment. The CFD simulations predicted higher flame tilt angles for the drilling rig case for higher flow velocities, indicating the influence of a varying wheelhouse/mudguard construction and tyre geometry on the flame tilt angle. The construction of the loader resulted in a flow behaviour, where the short distance to the front mudguard/tyre and the separation of flow directly downstream of the protruding construction led to fire gases being steered past the front mudguard/tyre. In the drilling rig case, the longer distance to the front mudguard/tyre led to fire gases being directed towards the body of the vehicle after passing the area with flow separation. An increased knowledge of the tyre fire risk on mining vehicles and mitigating measures would improve the fire safety in underground mines.

Feb 10, 2022

By J. A. Lombardi

Acid-Minesite-Solutions (AMS) are defined as copper-containing pit lake, tailing pond, acid-mine-drainage, and heap and waste dump irrigation solutions. All of these solutions are characterized by copper, acid and water contents that have value as individual commodities. HW Process Technologies, Inc. (HWPT) has developed nano- and hyper-filtration membrane methods for the separation of copper and other base metals, acid and water from AMS. These treatments are collectively called HWPT?s Engineered Membrane Separation® (EMS®) systems. The EMS® method of copper recovery produces small volumes of higher-concentration copper solution from large-volume, copper-dilute AMS. A case study of the 4,000 gpm Cananea EMS®-AMS plant for the recovery of copper from an acid-pit-lake resource is described. The EMS® method of copper removal from AMD and tails pond waters has been bench-scale demonstrated and are described, complete with projected budgetary capital and operating costs. Additional treatments for the recovery of sulfuric acid and high-quality water from the permeate (membrane passing) waters for the above-described AMS treatments are presented, with budgetary capital and operating cost estimates. [ ]

Jan 1, 2009

By R. Adsero

The volume of data produced by operating mines has increased substantially over the last 10 years. However, the volume of data and analytical capability has been negatively correlated to equipment productivity for at least the last seven years. In simple terms, as the volume of data has increased equipment performance has declined. Table (2010) tells us that ?The calamity of the information age is that the toxicity of data increases much faster than its benefits?. More data does not guarantee improving productivity; but more data is also not the cause of declining productivity. Similarly, when equipment performance does start to improve, (it must ? there really is no option if mines want to remain competitive), it will not be the data nor analytics which causes it; it will be the people using the resources at their disposal; including the data. Data and analytics can help if the toxicity of the data can be managed. The simplest form of business improvement using data is benchmarking. The objective of benchmarking is to understand and evaluate the current position of a process in relation to ?best practice? and to identify areas and means of performance improvement. The application of benchmarking involves four key steps: (1) Analyze and understand in detail existing processes; (2) Analyze and understand the processes of others; (3) Compare your own performance with that of the others analyzed; and (4) Design and implement the changes necessary to close the performance gap(s). There are however, many in the mining industries who have shunned equipment benchmarking because they believe that, ?every mine is a pilot?. In other words, the differences between mine operations make comparisons between them of little value. This paper will present a valid approach to benchmarking equipment performance and reliability, accounting for the differences and similarities between operations, producing a result which can be used to add value to mines around the world.

Feb 23, 2014

By D. W. Park

Underground room-and-pillar mining operations in the Warrior Coal Field in Alabama frequently suffer instability due to soft floor and thinly-laminated immediate roof. The investigation covered by this paper concerns a mine that was experiencing ground-control problems with weak floor conditions. Four hundred ft above the presently producing seam, another seam has been mined out. Several roof falls occurred locally, and as much as two ft of floor heaves have been experienced. The paper presents the results of comprehensive analysis conducted on floor heave, roof sagging, and the influence of the mined-out seam using instrumentation and numerical analysis.

Jan 1, 1991

By Jerry C. Tien

Without a doubt, the scope of China?s coal boom has been nonstop. Despite the world economic slowdown, China?s year-on-year gross domestic product (GDP) jumped 10.3 percent year-on-year in 2010, boosted by a faster than expected 9.8 percent expansion in the fourth [ ] quarter. And, the first quarter of 2011 expanded another 9.7 percent. According to a frequently cited statistic, the country is building two mid-sized coal plants each week. This amounts to a yearly increase equivalent to the entire power grid in the United Kingdom. China?s coal production was doubled in the last 10 years, from 1.044 Gt (1.15 billion st) in 1999 to 3.2 Gt (3.52 billion st) in 2010. This is 3.2 times the U.S. production (986 Mt or 1.085 billion st) and nearly half (46.3 percent) of the world?s total coal production (6.91 Gt or 7.6 billion st). This rapid increase of demand for coal has made China the world?s largest coal importer in 2009. With the economic situation improving, this trend is expected to continue.

Jan 1, 2011

By Russell Barr

Operational excellence is generally known as a management system integrated across critical functions that is geared towards continually improving operational performance. Functional areas such as health, environment and safety, quality and human resources are the focus of many corporate-wide operational excellence programs. Operational excellence also focuses on improving areas such as customer orientation, employee empowerment as well as process, and systems optimization. It is widely viewed as critical to sustaining business performance improvement. Although it is difficult to find a universally accepted definition, or even common foundation in many respects, operational excellence remains a popular term in the business world. Many organizations have developed their own version of organization excellence, influenced by such individual factors, other similar institutions or even third-party service providers. A mining organization is no different from other organizations in that adopting and implementing effective operational excellence programs can dramatically improve business execution and performance across regional or global interests. This paper brings together various perspectives of operational excellence and reconciles them for a useful composite for the mining industry. While most agree that operational excellence should include normal functions in a manufacturing operation such as production, maintenance and engineering and processes such as quality, environmental and continuous improvement, many other factors for operational excellence seem to vary from perspective to perspective. Thus, programs that manufacturers engage in may seem the same, but may, in fact, be different in key areas. This may affect organizational performance in tangible ways. Management must buy into the company?s definition of operational excellence and be dedicated to achieving it. A review of many of the existing definitions of operational excellence, explicit or embedded as part of a program, seems to yield the following common factors: ? It should help organizations better execute their processes and services. ? It should be geared towards improving quality ? It requires that the various operations should be aligned with the overall enterprise strategy. ? It should be geared towards continuous improvement. A composite of operational excellence definitions suggest that it is: ? Geared towards helping the organization achieve sustained profitability; ? tied to strategic alignment and business objectives; ? tied to solid investment strategies; ? integrated as part of the culture, process, time plan and performance; ? a relevant performance measurement system; ? extended to include all aspects of the supply chain (including external suppliers); ? integrated with health, safety and environmental (HSE) aspects. And, while the pursuit of operational excellence intuitively suggests that businesses should improve, it is very difficult to achieve given the difficult challenges facing companies today. Mining businesses face numerous pressures to perform in a global marketplace such as demand, energy cost, variable cost and pricing fluctuations as well as infrastructure challenges to further confound the environment. Companies generally must look to the following:

Jan 1, 2009

By S. K. Pan, R. Venugopal, L. A. Kumaraswamidhas, Rakesh Prasad, Chandan Pandey

Cold compressive strength (CCS) and apparent porosity (AP) of pellets are essential properties regarding the burden of blast furnaces. The optimal required values for industries are 2.5 KN CCS and 21% AP. Blaine fineness and firing temperature are the decisive parameters analyzed here. During firing, microstructure phases such as silicate, hematite, and pore are formed. The phase’s grain density during induration influences the pellet’s CCS and AP. The influence of the factors over the response is evaluated by I-optimal (response surface methodology) design. Blaine fineness, firing temperature, pore phase grain density (PPGD), silicate phase grain density (SPGD), and hematite phase grain density (HPGD) affect the CCS and AP of pellets. The RSM-I-optimal predicted responses with a coefficient of determination (R2) of 0.89 for CCS and 0.91 for AP of iron ore pellets. Optimal conditions were Blaine no. = 1668 cm2/g, 1250 °C firing temperature, PPGD value 90 no/mm2, SPGD value 250 no/ mm2, and HPGD value 490 no/mm2, with 4.5 KN CCS 27%. The induration processes were investigated through statistical design of experiments for process optimization. Statistical analysis indicated the direct and interactive influence over CCS and AP. In this study, RSM-I-optimal modeling is used for iron ore pellets processing. The I-optimal prediction could be applied to make the process economical because information is obtained through fewer experiments.

Aug 18, 2020