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By M. Sandin

According to the world bank1, the mining industry consumes up to 11 percent of global energy use. In comparison, 70 percent of mining projects from the six largest mining companies operate in water-stressed regions. To steer the direction of the process industries toward more sustainable practices, more than 40 governments have adopted a price on carbon. This measure includes additional taxes on the use of fossil fuels, trade programs, new standards for renewable energy, energy efficiency mandates, more stringent emissions regulation, carbon offsets, etc. This emphasis is also supported by investors shifting their priorities to reduce risk by focusing on long-term plans, including environmentally friendly operations. The metals and mining industry is at the core of the green energy mix and electrification of vehicles. This new trend creates an astronomical increase in demand for minerals. Under a 2-degree scenario, according to the latest analysis from the world bank, as new energy technologies continue to grow, it is expected that all minerals to double in demand, and the distribution of these materials will depend on their application. • Solar panels, will account for 87% of the aluminum demand, and more than 95% of silver • Wind turbines and geothermal plants will require 98% zinc and 64% titanium. • Solar and wind energy alone will demand more than 74% of the global supply of copper, and this is without considering wiring or other infrastructure to connect the grid • Battery storage accounts for 100% of the graphite and lithium demand. (Hund, 2020) • Other materials, such as nickel and steel, are also projected to more than double in demand as they are cross-technology minerals. These materials require a manufacturing process that is accountable for the emissions proper of the transformation process. It requires that these processes move from a hindsight mode focused on reporting to a forecasting mode based on run-time measurement of GHG emissions. This is a critical first step in companies realizing an economic return for doing the right thing for the environment and their communities.

Feb 1, 2023

By H. Michael Breza

Texasgulf Inc. installed bucketwheel excavators and overland conveyor sysems at its Aurora, NC phosphate mine o increase the productivity and flexibilty of the surface mining operation. This ;ystem has significantly improved overrall. Its flexibility is evidenced by adapation to operation requirements, such is mining area moves, movement of xcavated overburden to designated ites, selective handling of overburden, poll placement contouring, and proiding an environmentally sound and afe operation. The system's productiv:y is evidenced by case studies relating. overall production, excavation rates nd cost-effectiveness. There are many competing alternaves available for excavating uncon)lidated overburden: truck-shovel, raglines, dredges and bucket wheel ticavators. These alternatives also may used in tandem to recover reserves icated at greater depths.

Jan 1, 1993

By L. Xinghua

Limonite is a general term for a group of amorphous iron oxide and iron hydroxide materials. It is considered as one of the very refractory iron ore types due to its wide variation in chemical composition, iron content, moisture content and easily sliming in the course of comminution. Iron grade of test sample is 25.48%, the iron minerals are mainly limonite; and the gangue minerals consist of quartz and feldspar in majority, secondarily silicate minerals. In this test work, high intensity magnetic separation (HIMS)-cationic reverse flotation and magnetic roasting-low intensity magnetic separation (LIMS) tests were conducted on limonite ore. The test results show that the concentrate with iron grade of 50.97% and recovery of 68.50% can be obtained by HIMS-cationic reverse flotation technique; while using magnetic roasting-LIMS technique, the better concentrate indexes of iron grade of 60.36% and recovery of 89.71% are achieved, and the iron grade of tailing is only 4.42%. Therefore, the magnetic roasting-LIMS technique is a better suitable method for beneficiation of low-grade limonite ore. Keywords: Low-grade limonite; Mineralogy; HIMS; Cationic reverse flotation; Magnetic roasting; LIMS

Feb 27, 2013

By W. L. Garrison

Improvements continue to be made in rapid excavation and tunneling technology. There are several ways to examine the impacts of such improvements. The most common procedure is to monitor current developments and to evaluate prospects for expansion of present types of uses. Other approaches are called for, however, if the technology might be used in ways not now imagined, if the search is for information for managers of technology development, and if the issue is that of the wise use of the technology by society. The first section of the paper will pose these matters as questions. These questions will be examined from the point of view of the processes of technology development and utilization, and then further examined against the backdrop of processes at work within the urban area. Such an examination will provide insight into the way technology developments should proceed. The final section will present some comments that may be useful to those guiding the development of the technology and to those who might provide leadership for its wise utilization. THE QUESTIONS Three questions are posed: 1. Are there uses for the technology beyond further penetrations of its present markets? 2. Can information be supplied to managers of technology development so that they may improve the assignment of priorities among development choices? 3. How can society make wiser use of the technology?

Jan 1, 1974

By Katzer R. Klimpel, J. Sewell

Dr. Roussey Roussev The use of chemical additives on grinding is of significant importance considering the high energy consumption of grinding processes. My research indicates that the dispersant approach explains the effects, in this particular case of wet grinding. Further, the dispersant approach combined with torque measurements give the possibility of clarifying the mechanisms involved when using grinding aids. I find the conclusions derived from the data obtained to be correct and useful for grinding. In general, I agree with the explanations. However, I would like to discuss several additional points that I consider to be important, and in the same time to mention some of my own results from investigations similar to those presented in the study under discussion. The "bed volume concept" and the change of slurry viscosity explain adequately the data plotted on fig. 3, in conjunction with Figs. 1 and 2. However, the significant increase of the average torque in the case of 83% solid with XFS-4272 introduces the necessity of establishing the optimum of percent solid when dispersant is used. For example, the optimum percent of solid for different materials varies. One of the reasons is the material's mass density. On the other hand, it is necessary to determine the concentration of the chemical used. Because of this, it would be interesting to know how the cited concentration was selected. The supportive discussion and verification by Dr. Roussev, with results similar to that of the paper, is appreciated. I will try to answer the additional questions he has raised. To begin with, the mill was fitted with six lifters of approximately one-quarter inch height. There has been extensive lab and plant level work to understand downstream influences of using dispersants like XFS-4272*. In sulfide ore processing, which is the area in which most industrial scale testing has been performed with this approach, neutral to positive influences have been observed. For example, positive effects (e.g., increased recovery) have been noticed in flotation operations involving ores that have a tendency to produce excessive slimes upon grinding. (1) Also, the use of a dispersant has been shown to demonstrate a positive influence on classification by improving the sharpness of separation and preventing a decrease in d50 value that usually accompanies increasing flow rates to classifiers.(2) The biggest potential downstream problem is in thickening, which at the dosages involved, has not been a problem in plant scale usage. The commercial price of dispersants like XFS-4272 is quite variable depending on source, concentration, etc, but a typical cost of XFS-4272 to achieve a 10% increase in throughput in industrial mills has been between 20 and 35- US per ton of feed ore (1981).

Jan 12, 1982

By P. Jurovcik, D. Yantek, D. Ingram

The National Institute for Occupational Safety and Health (NIOSH) identified hearing loss as the most common job-related disease in the United States in its 1996 National Occupational Research Agenda. Previous studies by NIOSH have shown operators of surface drill rigs without cabs are commonly exposed to A-weighted sound levels exceeding 90 dB. During hammer-drilling, A-weighted sound levels exceeding 100 dB were recorded at the operator station. NIOSH collaborated with a local drilling company to design and install a partial cab between the operator and the drill steel in an effort to reduce the sound level at the operator station. Sound level measurements in the field show the partial cab reduces the A-weighted sound level by 5-9 dB at the operator’s left ear and 2-5 dB at the operator’s right ear while hammer-drilling. This paper will briefly discuss the preliminary design of a cab and the testing of materials for construction of the prototype. Explanation of the ideas behind the prototype design and fabrication will be covered. Finally, the field test method and results will be discussed in detail.

Jan 1, 2007

By Lane White

In mid-April 1992, MINING ENGINEERING mailed a survey questionnaire relating to mining shovels and hydraulic excavators to 125 SME members working at surface mines or at the headquarters of companies that operate surface mines. The mailing was directed to individuals whose titles indicate that they have management or mine planning responsibilities for surface mining operations. A total of 56 usable surveys returned by June 17 are the basis of this report. Precious metals mines Eighteen precious metals mines or mining companies returned completed surveys in time to be included in this report. Of these, 14 use hydraulic shovels only for both ore and waste, I uses both hydraulic and rope shovels, and 2 use Caterpillar 988 front-end loaders for both ore and waste. (Of the latter 2, neither expects to be in the market for a shovel in the next three years. I of these 2 placed Harnischfeger P&H number one and O&K number two in response to the question, "Based on your current knowledge of their machines, which manufacturer would you likely chose to supply new shovels or excavators to a mine or mines operating under your responsibility, if you were in the market?") Another uses front-end loaders, make not designated. The latter does not expect to be in the market for mining shovels or excavators within the next three years. Of the final total of 14 precious metals mines using only hydraulic excavators to load ore and waste, 8 use Hitachi excavators only, 1 uses Demag excavators only, 1 uses Liebherr excavators only, 1 uses O&K excavators only, 1 uses Harnischfeger P&H and O&K excavators, 1 uses Harnischfeger P&H and Hitachi excavators, and 1 uses Hitachi and Demag excavators. Of the 14 precious metals mines using only hydraulic excavators, 7 use excavators in the 7.6 to 11.5 m; (10 to 15 cu yd) size range. Of these 7, 5 use only excavators in this size range, and they are used to load both ore and waste. 1 of the 7 also uses 11.5 to 17 m' (15 to 22 cu yd) excavators, and I also uses a 17 to 23 m3 (22 to 30 cu yd) excavator. Of the 7 remaining of these 14 precious metals mines that use only hydraulic excavators, 3 use 11.5 to 17 m' (15 to 22 cu yd), 2 use 17 to 23 m3 (22 to 30 cu yd), and 2 use less than 7.6 m' (10 cu yd) units.

Jan 1, 1992

By Michael J. Robison, Wojciech F. Klecan, Robert L. Horner

Since 1928, nearly 64 km (40 mi) of tunnel have been excavated within the relatively soft Cooper Group, more commonly known as the “Cooper Marl,” for water supply and transporting wastewater in the Charleston area. The majority of these tunnels are unlined and still in operation, while others collapsed shortly after excavating. Tunnel behavior and support requirements vary considerably in this material due to differences in geotechnical properties. The 4.8 km (3 mi) long, 2.4 m (8 ft) diameter Bushy Park Water Tunnel, completed in 1997 for Charleston’s Commissioners of Public Works(CPW), required no ground support. By comparison, the 1.6 km (1 mi) long, 2.4 m (8 ft)diameter Harbor Wastewater Replacement Tunnel now under construction needs continuous support close to the advancing face, despite being located in the same geological formation. Case histories and general guidelines for designing tunnels in the Cooper Marl are presented.

Jan 1, 2001

By I. Gombköto, J. Bohm

"In Europe, and therefore in Hungary opening a new mine is harder and harder. Depletion of mines, unfavourable legal and economic changes, and growing public concerns are the main reasons. Social and economic interests require total utilization of mineral raw materials of the operating mines, and furthermore utilization of waste heaps of the former mines. There are 5-6000 waste heaps of the operating and the closed mines in Hungary. 2000 of these waste heaps have already been estimated, and researches show that total amount of waste heaps can be calculated to 1 billion tones. These researches left out of consideration waste heaps exploited and placed in deep lignite mining. In several projects and researches we analysed processing of waste heap and possibilities to use its components. A processing technology for utilizing waste heaps has been developed based on laboratory and pilot plant tests. Great amount of useful materials of quarrying waste heaps can be utilized with this technology. Tests were also done for processing waste heap of a former ferrous metals mining. The developed processing technology contributes to use these waste heaps as aggregate for cement industry, as dielectric and aggregate for construction. The essay presents in details main characteristics of waste heaps, technologies already used for processing waste heaps of quarrying and ferrous metals mining, mass balances and qualitative parameters of the end products."

Jan 1, 2011

By S. K. Oraee

Managers always look for systems with minimum hazards. The hazards create problems for performance of projects. The largest and most important hazards of working underground mine can be related to health, safety and environmental, because if one of these sectors be in hazard, maybe lead to close mine. Failure mode and effects analysis (FMEA) is a widely used quality improvement tool to identify the potential failure modes for measuring reliability of a product or a process. FMEA is performed by developing a risk priority number (RPN), which is the product of severity, occurrence, and detection ratings. On the other hand, with regard to uncertainty in the decision-making, fuzzy theory will be able to model this uncertainty. Fuzzy FMEA provides a tool that can work in a better way with vague concepts and without sufficient information than conventional FMEA. This article by using Fuzzy FMEA and based on HSE criteria evaluate hazards of Parvade No. 1 Mine in Tabas Coal Mine. The results demonstrate the most hazardous parameter is rock burst in this mine.

Jan 1, 2011

By Peter Amelunxen, Craig Lockhart

Significant effort was made in 2003 and 2004 to upgrade the existing instrumentation and process control infrastructure at the Phelps Dodge Bagdad copper concentrator. Specifically, • cameras were installed on the feed belt for online image analysis data, • ultrasonic level sensors were installed for froth height and sump level control, • a trial froth image system was installed on one of the rougher rows, and • a new expert system to tie everything together was integrated and tuned in-house. Control philosophy, observations, opinions, and general tips and tricks are discussed with the hope of assisting other plant personnel and expert system integrators.

Jan 1, 2005

By Paul Wellman

The energy problem of the U. S; was emphasized by the oil embargo of late 1973 and early 1974 and it seemed for a time that the Federal Government, under pressure from the general public, might take some corrective action. However, this was not the case. With the gasoline lines gone and an apparent plentiful supply of petroleum products, public concern quickly dissipated., This country is more vulnerable to an oil embargo today than we were in 1973-1974 and this fact should be of concern to all our people. Since 1968, we have used oil and natural gas at a much more rapid rate than we have been able to find new domestic sources; thus, there is an increasing gap between domestic production and consumption and we have filled the gap with ever increasing oil' imports. These imports have increased at an alarming rate in the recent past, some 58 percent in 1976 compared with 1975. Imports are nearing 8 million barrels per day. Then, by applying some simple arithmetic, at $12 per barrel, the resulting trade deficit is $96 million per day or $35 billion per year. Obviously, this cannot be tolerated by our economy over a long period of time. Historically, we have shifted from one fuel to another as is shown in this slide. In 1850 about 90 percent of our fuel requirements came from direct combustion of wood, by 1900 we shifted to coal for 70 percent of our fuel, and now about 78 percent of fuel requirements comes from oil and natural gas. The difference is that the previous shifts were voluntary and the one facing us now is of necessity.

Jan 1, 1977

If one can embrace the medical analogue, much of the mining industry currently suffers from a massive bacterial infection. When pyrite-bearing or sulfide-bearing rock formations, tailings, or mine wastes are infected by Acidithiobacillus ferro-oxidans, the likelihood of forming acid rock drainage (ARD) is almost guaranteed. The ?pharmacy? of antibiotics available is extensive, ranging from solid alkaline amendments like limestone to liquid ?medicines? such as sodium lauryl sulfate, sodium thiocyanate, waste milk, and bipolar lipids. Unfortunately, the ?geo-medical? teams of geochemists, microbiologists, engineers, and mine managers lack the tools to surgically apply these active ingredients where they are needed most with a minimum of waste. Distribution of fine grained limestone on the surface of an acidic mine waste dump is analogous to applying a bandage soaked in antacid to treat an upset stomach. The implementation of up-to-date best management practices has not healed the patient; an equivalent combination of hypodermic needle, cyber knife, and arthroscopic probe is clearly needed. Using an engineered, flow-able or pumpable foam or pHoam? as the medicinally analogous ?dextrose delivery solution? for solid and/or liquid ?geo-antibiotics?, the authors have combined off-the-shelf technologies that have been previously applied in solving geotechnical problems in the mining industry. A patent for the innovative process is pending. This paper discusses method concepts and the advantages it could provide over conventional BMPs.

Jan 1, 2012

By T. W. Beck

Overexposure to respirable dust remains a widespread health hazard to roof bolter occupations in underground coal mines. Recently implemented mist drilling technology was evaluated for its effectiveness in controlling respirable dust exposures for roof bolting personnel. This work presents the findings from NIOSH field and laboratory studies comparing respirable dust levels on mist drilling roof bolter machines to dust levels measured on machines using a conventional vacuum drilling system. Gravimetric and instantaneous respirable dust samples were collected for multiple drilling cycles. These dust measurements were used to assess the potential dust control capabilities relative to conventional drilling. Controlled laboratory tests found 0.3 mg/m3 more respirable dust with mist drilling than with the conventional vacuum method. A separate field investigation of the two techniques observed higher dust levels around the mist bolting machine.

Jan 1, 2008

By William R. Yernberg

What a difference a year makes. One year ago, the iron mining industry and the steelmaking industry in the United States were in trouble. Many companies were in bankruptcy, and talk of plant and mine shutdowns was rampant. At that time, it seemed difficult, if not impossible, to remain competitive with imported steel. In addition, the World Trade Organization declared as illegal the tariffs placed on imported steel. And many questioned the viability of the ironmining and steel industry in the United States. At that time, global economic conditions were the main contributors to the industry’s problems. However, since last year’s meeting, changes in global economics have actually helped the steel industry in the United States. Heavy global demand for steel has caused raw-material shortages worldwide. Much of the increased demand is a result of the economic boom in China. In addition, because of a weak U.S. dollar and higher international freight rates, steel imports into the United States have been reduced to about 50 percent of recent levels. These factors have contributed to a rebirth of the U.S. iron mining and steel industries.

Jan 1, 2004

By M. Gouet-Kaplan, J. A. Finch, S. Gélinas

Methylisobutyl carbinol (MIBC) and methoxy polypropylene glycol (Dowfroth 250) bubble thin films were characterized by composition and thickness determinations, using FT-IR spectroscopy and UV-Visible spectrophotometry, respectively. The infrared investigation indicates that the role of frother molecules in creating bubble thin films is based on their effectiveness in inducing H-bonding reorganization of the surrounding free water molecules into a coherent network. From UV-Visible interference patterns, it is found that MIBC forms films with a measured critical end thickness of less than 160 nm, compared to 612 ± 30 nm for Dowfroth 250. The observed values of the free water layer thickness are comparable at 5.65 ± 0.28 µm for MIBC and 6.75 ± 0.34 µm for Dowfroth 250. A higher stability of an MIBC bubble over a Dowfroth 250 bubble is related to the different polarization and orientation of the molecules sustaining the boundary surface water network. The findings are used to explain the different action and associated froth characteristics of the two common industrial frothing agents.

Jan 1, 2006

? The economic health and national security of the U.S. depends on the continued availability of, and access to, reliable and affordable energy and mineral resources. However, America is hindered by a costly, inefficient and often redundant regulatory structure that thwarts domestic investment, expansion and job creation. The annual cost of federal regulations in the U.S. increased to more than $1.75 trillion in 2008; averaging $8000 per employee.(The Impact of Regulatory Costs on Small Finns, SBA, 2010) ? The complexity, uncertainty and delays within the current permitting system places the U.S. at a competitive disadvantage with many other countries that have both abundant mineral resources and a more welcoming business and regulatory climate. As a result, American and international mining companies often move overseas or across borders to invest capital, create local employment, and produce the critical minerals America must then import at higher cost, while sacrificing employment and economic stimulus. ? According to Behre Dolbear, the U.S. is ranked lowest globally due to the lengthy permitting period required before mine development can commence. (Where not to Invest, 2010).

Jan 1, 2011

By Tim O’Neil

Dressed in black tie and Victorian attire, some 200 people came to Leadville, CO, for a September weekend featuring a National Mining Hall of Fame and Museum (NMHF&M) induction banquet and a scenic mountain train trip to Fremont Pass and the Climax Mine. The 18th annual induction banquet on Sept. 17 began with cocktails and a open house. It was a chance for visitors to tour the National Mining Museum including the new Hennebach Wing, opened in February. The new wing is named in honor of Ralph Hennebach, retired chairman of Asarco. Formerly Leadville Junior High School, the Hennebach Wing encompasses more than1,440 m2 (15,500 sq ft) of floor space in two stories. One prominent feature is a 1923 Wills Sainte Claire touring sedan. Climax Molybdenum donated this first all-molybdenum steel motorcar. Docents were available throughout the museum to give banquet attendees directions and answer questions.

Jan 1, 2005

By R. Leithner

The need/wish to sequestrate CO2is based on the assumption of the International Panel of Climate Change (IPCC), that CO2 maybe the major driver in climatic changes, i.e. especially the anthropogenic CO2emissions due to the combustion of fossil fuels like coal, oil and natural gas will increase the atmospheric CO2-content, which will lead to higher temperatures in the atmosphere. The 0.03% CO2in the atmosphere have a 22% share of the natural greenhouse gas effect of 33 K necessary for life on earth. The main share of 62% has the water vapour in the atmosphere. Only if one concentrates on the greenhouse gas effect of the gases beside water vapour, CO2 becomes most important with 58% influence. In addition there are other influences on the climate like: • Eccentricity of earth’s orbit, precession of orbital plane, obliquity and precession of earth’s rotation axis (Milankovitch’s theory) • Sunspots and magnetic field of the sun • Changing streams in the ocean • Volcanic activities • Distribution of continents on the surface of the earth • Impact of meteorites • Change of insulation by interplanetary dust [Muller, R.A. 2000] etc. To answer the question, if the CO2-content in the atmosphere has an important or exclusive influence on the earth atmospheric mean surface temperature, one should look into history. Figure 1shows the mean temperature of the atmosphere and the atmospheric CO2-content time histories 1 billion years back; no correlation can be found between them. Nevertheless a lot of countries have committed themselves to reduce their CO2-emissions.

Jan 1, 2004

Twenty field-scale tests were conducted in a 28 MW pulverized coal power plant in Healy, Alaska, to examine mill power consumption in relation to coal grind size. The intent in this field-scale study was to verify if grind size truly impacted power consumption by a detectable amount. The regression model developed from the data indicates that grind size does impact mill power consumption, with finer grinds consuming significantly more power than coarser grinds. However, other factors such as coal hardness (i.e., the lower the Hardgrove Grindability Index, or the harder the coal, the higher the power consumption) and mill throughput (i.e., the higher the throughput, the higher the power consumption) had to be included before the impact of grind size could be isolated. It was also observed that combining amperage and flow rate into a single parameter, i.e., specific amperage, hurt modeling. Cost analysis based on the regression model indicate a power savings of $19,972 per year if the coal were ground to 50% passing 76 mm rather than the industry standard of 70% passing 76 mm. The study also demonstrated that size reduction constituted a significant portion of the power consumption.

Jan 1, 2008