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By V. Castranova, L. Wu, K. Van Dyke, J. Gutierrez, V. Vallayathan

Since it has been demonstrated that silica caused phagocytic cells to activate lipoxygenase metabolism of unsaturated fatty acids we thought selective inhibition of this metabolic pathway might be helpful in treatment of silicosis. It is known that lipoxygenase metabolism plays a role in the pathogenesis of a variety of inflammatory and hypersensitivity conditions. Further, it is believed that the alveolar phagocytic cells which engulf silica begin the inflammatory cycle which produces the metabolic products, cytokines and growth factors which causes fibrosis in the lung. There have been indications that drugs which inhibit lipoxygenase can inhibit fibrosis from other causes. Previously, we developed a method which detects the activity of lipoxygenase metabolism by measuring free radical oxidation via light production or chemiluminescence (CL). We decided to apply this method to phagocytic cells that would be found in the lung in the presence of silica with and without newly developed inhibitors of the lipoxygenase reaction. We used drugs which inhibit lipoxygenase directly including AA861 (TAKEDA), A63162 (Abbott), and an inhibitor that scavenges free radicals produced from the lipoxygenase reaction, nordihydroguairetic acid. In addition we used an indirect inhibitor, tetrandrine. We found drug inhibition of silica activated CL from alveolar macrophages, neutrophils and human leukemia (HL-60) cells differentiated with DMSO. Nordihydroguairetic acid 2x10-5M produced almost complete inhibition in all three cell types. In human leukemia cells (HL-60) A63162 and tetrandrine were equally inhibitory at 42% while in human neutrophils A63162 and tetrandrine were less active 22 and 10% respectively. In macrophages A63162 and AA861 were less than 50% inhibitory to cellular CL at 2xl0-5M. Direct assay of tetrandrine (2x10-5M) with sodium arachidonate and soybean lipoxygenase reveals no inhibition. All antilipoxygenase drugs regardless of mechanism were inhibitory to cellular chemiluminescence from all three types of phagocytic cells. These drugs alone or in mixtures could prove useful in treatment of silicosis.

Jan 1, 1991

By James R. Brown

Mount Isa Mine should be regarded as a large mining complex rather than one mine. This arises from the geography, variety and extent of the orebodies, the mining methods, and the use of 14 shafts for ventilation distribution. A brief resume is presented here since comprehensive descriptions of lead-zinc mining methods {11}, copper mining methods {2 }{3}, geology 241, stope fill {5} and ventilation techniques {6}{7}, have all been published in the last five years. Mining extends over a north-south strike length of 2.5 miles (4 Ian) with a maximum width across dip approaching 3 200 ft (1 Ian). Current mining is to a depth of 3 150 ft (960 m) with the ore hoisting shafts extending 660 ft (200 m) deeper. The composite longitudinal section, Figure 1, shows a representational disposition of the copper and lead-zinc-silver orebodies in the central shaft complex where the main service and hoisting shafts are located. To the south the X41 man and materials shaft provides access to the copper area. The mine layout is typical of high tonnage track- less mines, utilising a large diesel fleet, raise- borers and some large diameter hole stope drilling. Mining methods include sublevel open stoping, slot and massfire, and a trial vertical crater retreat in the copper ore, and sublevel caving, sublevel open stopes with and without rib pillar recovery, and mechanised cut and fill in the numerous lead orebodies. All ore reports to one of the three crushing systems located below 19 level in the central shaft complex. Copper ore is hauled exclusively along the 19 level computer assisted Rockflo haulage system, and lead-zinc-silver ores report via central orepasses from Granby haulages on 13 level and 15 level. Tonnages hoisted during the 1977178 financial year were 5.0 million for copper at 3.2%. and 2.3 million for lead-zinc-silver at 7.8%. 6.3% and 7.06 oz/ton (216 g/tonne) respectively.

Jan 1, 1980

By Jerzy F. Sobala

Large - scale tests at the Polish Safety in Mines Institute /established in 1925 as "Barbara" Experimental mine/ performed in underground and surface experimental galleries, simulating conditions in roadways in mines, are the basic source of knowledge about development and propagation of explosions. Investigations up to 1973 were performed under the Institute's former research director Professor W.B. Cybulski s supervision, whose handbook concerning combating of coal dust explosions in collieries has been also published in the U.S. (2), and are continued until now. For investigating explosions the "Barbara" Mine disposes of 170 m /7.5 sq m/, 200 m /5 sq m/ and 400 m /7.5 sq m/ underground gallieries as well as of 10 m, 25 m, 44 m and 100 m surface galleries. For example, in the 200 m gallery more than 5200, and in the 400 m gallery - more than 2200 test explosions have been performed. Basing on determination of explosion hazard in roadways in collieries and on data of scientific research performed at the Safety in Mines Institute, the strategy of combating the explosion hazard in mines was elaborated; it includes mainly diminishing of coal duet. deposition in roadways, and -because of the possible inefficiency of this safety means in some roadways in mechanized collieries -- the introduction of three additional defence lines against coal dust explosions. It should be mentioned that at the "Barbara" Mine the problem of coal dust explosion initiation was elaborated as contract work for the U.S. Bureau of Mines. The main aim of this paper is to discuss some aspects of methods and measures for combating coal dust explosion hazard in highly mechanized mines in the Polish mining industry where in some roadways explosible coal dust is present, but it is not the aim to evaluate the effectiveness of methods and measures for diminishing the make-up of coal dust and coal dust deposition rates in roadways.

Jan 1, 1980

A Mineração da Trindade (Samitri) is a major Brazilian iron ore producer. Founded in 1939, privately owned Samitri operates six mines with a total production capacity of 14.5 Mt/a (16 million stpy). The mines are located in southeastern Brazil in the state of Minas Gerais. They are operating in the iron ore quadrangle, Brazil's primary iron ore-producing region. In addition to iron ore production, Samitri has the capability to produce 350 kt/a (386,000 stpy) of ferruginous manganese ore from two mines, also located in the iron ore quadrangle. Historically, about 70% of Samitri's production of lump ore, sinter feed and pellet feed is exported. Destinations include Belgium, Luxembourg, France, Germany, Trinidad and Tobago, China, Turkey and the United States. Alegria Mine In September 1989, Samitri started a new processing plant to treat itabirite, a low-grade iron ore. The goal of the plant was to produce sinter feed (coarse fraction) and pellet feed (fine fraction). Primary separation of sinter feed from pellet feed was accomplished with conventional vibrating screens making a 0.4-mm (40-mesh) cut. The screen oversize was stockpiled as sinter feed. The undersize was deslimed with hydrocyclones and upgraded by conventional froth flotation. Resulting pellet feed grades ranged from 3% to 3.5% Si02. A change in pellet feed requirements by Samarco Mineração SA, a Samitri subsidiary, called for Si02 levels below 1 % and increased production levels. Moreover, market demands called for a change in sinter feed size distributions. Unfortunately, lower pellet feed Si02 levels could not be achieved with the existing process. This was because of the presence of 35% +0.15 mm (+100 mesh) in flotation feed. Flowsheet development. Laboratory and pilot-plant studies conducted at Samitri's research facility found that to achieve lower Si02 levels, the +0.15 mm (+100 mesh) in flotation feed must be kept below 5% to 10%.

Jan 1, 1997

By Gregg R. Bierei

Arch of Illinois is a mining complex comprised of two surface and two underground mines located in Perry County, in southern Illinois. The company a division of Apogee Coal Co. of St. Louis, MO. Arch of Illinois' two surface mines, the Captain and Horse Creek Mines, use large stripping shovels and cross-pit bucketwheel excavators to remove overburden from three seams of coal, the Herrin No. 6, Harrisburg No. 5 and Danville No. 7. All are considered high sulfur reserves. The two underground operations are managed by Arch of Illinois. They are the Kathleen Mine and the newly constructed Conant Mine, which began production in 1991. Both underground mines are continuous miner operations. They mine the No. 6 coal, which is about 1.8 m to 2.1 m (6 to 7 ft) thick. All coal is currently transported by truck to a central preparation plant located at the Captain Mine. This preparation plant produces 27 kt/d (30,000 stpd) of clean coal. Production in 1992 reached 5.9 Mt (6.5 million st) of saleable coal. Of that, about 66% or 4 Mt (4.4 million st) are produced by the surface mines and the rest the by under ground operations. Change is in the wind for Arch of Illinois. In 1988, 100% of all production (6.2 Mt or 6.9 million st) came from surface operations. By 1995, only 38% of production is scheduled from surface mines. And by the year 2000, 100% of production will from underground mining methods. Dwindling low ratio reserves, compounded by increasing environmental and land acquisition costs, coupled with more efficient underground mining equipment, have started an evolutionary trend toward development of underground reserves. For Arch of Illinois to maintain profitability of remaining surface reserves and to compete effectively mining underground, it must improve efficiency, productivity and cost reductions. These efforts are essential for maximizing current surface reserves and to ensure a continued existence in the presence of clean air legislation and the softening of the high sulfur coal market.

Jan 1, 1993

The 29th annual American Mining Hall of Fame Awards Banquet and Fundraiser sponsored by the Mining Foundation of the Southwest (MFSW) will be held at the JW Marriott Star Pass Resort, Tucson, AZ on Saturday, Dec. 3, 2011. Each year, one living inductee, two recipients of Medals of Merit, and up to five honorees from mining history are chosen by the MFSW for their outstanding contributions to the mining industry. Chilean Minister of Public Works and former Minister of Mining, Laurence Golborne Riveros will be the guest of honor, featured speaker and inductee into the American Mining Hall of Fame. Golborne Riveros was instrumental in managing the rescue of the 33 Chilean miners in October 2010 and in the coordination/management of the ?townsite? for family members, rescue support and the media. His engineering background and executive management skills made him ideally suited to assist in both a technical and managerial role in this emergency.

Jan 1, 2011

By Georges Cote, Ehsan Alavi, Eren Kusdogan

The City of Toronto's Coxwell Bypass Tunnel is currently being constructed by North Tunnel Constructors (NTC) ULC, a joint venture of Jay Dee Canada, C&M McNally Tunnel Constructors and Michels Canada. This project includes construction of approximately 10.5 km of 6.3 meter finished diameter rock tunnel, five 20 meter diameter storage shafts and eleven tunnel connection drop shafts, along with associated deaeration and adit tunnels. 120 m of Starter tunnel and 70 m of Tail tunnel were excavated with roadheaders to help with the launch of the TBM and as part of the contract base scope work. JayDee Canada in Collaboration with Everest Equipment Co. developed an innovative approach to design and build a stand-alone Ring Machine Erector nicknamed Enterprise to erect precast segmental lining in Starter and Tail tunnels in lieu of Cast-In- Place concrete. This paper describes the design and provides feedback on the innovative procedure used to install the rings.

Jun 23, 2024

By Yassine Lahmadi, Edoardo Trivellato, Christian Chereau, Bénédicte Robert

Within the framework of the adaptation of the South-East European Technicentre (Technicentre Sud-Est Européen TSEE), SNCF Voyageurs appointed Pini with the project management mission (MOE) for the design and construction monitoring of a road tunnel. This investment has a dual function: during the site transformation phase, it facilitates the work logistics (and shorten traffic flows); and in the operating phase, it is intended to ease all movements on the site over the long term. This is a limited-length gallery (50 meters) to be performed in conventional excavation below Poniatowski Avenue (Paris 12e). The excavation, crossing the entire width of the boulevard, constitutes a major challenge, given the very low coverage (less than 5.5 m), and the surrounding main infrastructures. The same project mis- sion includes the design of the tunnel accesses, via reinforced-concrete frame structures. The targeted design questions several aspects of its execution framework, and particularly, continuous operation must be guaranteed to the neighboring networks during the works. The installation of an umbrella- pipe all along the excavation profile, the progression in divided sub-sections, and the implementation of a complex monitoring system are hence key elements for limiting and controlling any deformation. An exhaustive 3D finite element modelling was performed, taking into account the detailed phasing of construction (pre-support, excavation in divided section, preliminary support and definitive lining), to dimen- sion the structures, and, overall, to analyze the impacts on the neighboring structures and facilities. During the execution phase (planned for mid-2024), monitoring activities with back-analyses as close as possible to the works are planned.

Jun 23, 2024

By Fathi Habashi

OXIDE ORES can be divided into two groups: 1) Simple oxides (Table 3.1). 2) Complex oxides. Those ores containing minerals composed of two oxides; an acid oxide (Cr2O3, Nb2O5, etc.), and a basic oxide (CaO, FeO, MnO), as shown in Table 3.2.

Jan 1, 1970

By J. F. Rakszawski, Robert P. D'Orazio

The use of cyanide in the processing of gold has been documented for over a century. It is still one of the more effective methods of isolating gold, as witnessed by the fact that in 1987 cyanidation was used in the processing of 91.5% of the gold produced in the United States.

Jan 1, 1990

By William H. McLemore

Geologists searching for carbonate rocks suitable for chemical uses traditionally have relied on extensive laboratory testing in order to locate strata or zones that might be suitable for mining. However, when considering the significant time and costs involved in sampling and performing chemical analyses, any exploration technique whereby fewer samples and analyses are needed would be of great value. In other words, if the exploration geologist could "zero-in" on select areas, considerable time and money could be saved. In general, the major-element chemistry of carbonate rocks is determined by the abundance of the minerals present. CaO occurs with CO2 as the mineral calcite, which is the primary mineral comprising allochems, matrix and sparry cement; MgO is found in high-magnesium calcite (many calcite fossil species contain appreciable amounts of MgO in solid solution), dolomite, and chlorite; iron occurs in pyrite and in limonitic stylolites, as well as in chloritic and glauconitic clay minerals; materials containing abundant Si02 are microcrystalline quartz (chest) silt-sized quartz, and clay minerals; and Al203 is found primarily in illitic, kaolinitic, and chloritic clay minerals. The presence or absence of these minerals determines the chemical composition of the carbonate rooks.

Jan 1, 1983

By H. Hinds

Plant testing of DuPont's Activator Technology in the vat leach circuit of the Homestake mine shows increased gold recoveries of 3-5%. Activators are catalysts of gold dissolution in cyanide solution. DuPont received the patent for this technology in January, 1996. The test was run in the west sand plant alternating control and activated vats to reduce the variability in head grade and cyanide consumption. Activated vats had gold in the preg solutions earlier, higher gold recovery, and lower gold residuals. Activator addition did not adversely affect mill operations or the environment. Optimization of the technology continues.

Jan 1, 1997

By Frank J. Foster

This Paper will deal with Bucketwheel Suction Dredging and its particular relationship to mining applications. There will be comparisons with other methods of suction dredging and descriptions of two recent bucketwheel installations in the mining area. The Directory of World Dredging Fleets published in the `larch 1984 edition of World Dredging magazine shows that there are about 1.000 conventional Cutterhead Dredges listed throughout the world with 289 in the United States. There are 242 Bucketline Dredges listed throughout the world of which only 6 are in the United States. These figures are not completely accurate because several units are known to the author that are not on the list and, of course, there may be others.

Jan 1, 1984

By The SME Sustainable Development Committee

The evolution of sustainable development in mining is recognized as a key contributor to sustainable development (SD), which is defined as the ability of current generations to meet their needs without compromising the ability of future generations to meet their own needs (Brundtland, 1987). This includes, in equal parts, social, economic and environmental impacts ? triple bottom line (Munashinge and Shearer, 1995). Alternately, sustainability has been defined in relation to social, natural, human, physical and financial capital. Our way of life relies significantly on the materials provided by mining, while mining activity affects the triple bottom-line or the five capitals. The mining community and its professionals have come to realize the importance of engaging all stakeholders in the discussion on sustainability. SME, as the leading professional mining organization, has been involved in these discussions. The society has various initiatives in sustainable development for members and stakeholders. The objective of this article is to: provide historical context for current trends in mining and SD and share SME sustainability initiatives ? their goals and rationales ? with the broader mining community. This article is timely because the past year saw two landmark forums on sustainable development: Rio+20 ? the 20th meeting of the United Nations Conference on Sustainable Development, and MMSD +10, the Mining, Minerals and Sustainable Development project 10 years on. Furthermore, this year marks the 10th anniversary of the Milos Declaration on the minerals professional?s responsibilities in achieving sustainable development, forums in which SME was involved.

May 1, 2013

By R. J. Sheets

"What is the primary responsibility of geo-engineers in mining? Early in my career, I was asked this question by an experienced engineer. After explaining some various tasks, I was informed that the main responsibility was to monitor. Although this proved true for many cases, I came to understand that monitoring is merely one means to achieve the primary responsibility of a geo-engineer — ensure the safety of all personnel. The potential for groundwater to impact stability allows this responsibility to be shared with hydrogeologists as well. Inherently, we monitor to identify risks; we analyze designs and develop models to mitigate risks; and we are provided opportunities to explain to supervisors the geo-risks to personnel and mine plans that will result from particular courses of action. A couple years ago, I took an opportunity to share experiences from the first several years of my career as a geotechnical engineer with junior geoengineering staff within my company. The intent was to share situations that were a part of my development, so they could learn and understand their responsibility to the safety of all personnel. Similarly, the purpose of this article will be to share these thoughts with new geo-engineers in the industry in order to help prepare them for the challenges they will face.What is our purpose?A senior hydrogeologist shared an experience that occurred in their career. The experienced hydrogeologist had spent some time with the hydrogeology staff, most of them relatively new to the mining industry, to understand how they viewed, and carried out, what they perceived as their responsibility at an active mining operation. After a couple months of observing and mentoring, the senior hydrogeologist met with everyone and posed the question “What is our purpose?” I am sure that most junior geo-engineers would start explaining different tasks or projects that they must complete. The list would include monitor ground water levels, track slope movement, evaluate designs, build models, oversee drilling programs, etc. These individuals did as well their supervisor. After going around the room allowing each individual to answer, the experienced hydrogeologist provided them the real answer to the question: Safety. If you examine the root intent of nearly every responsibility geotechnical engineers and hydrogeologists have, it is to apply our professional skills to ensure the safety of our workforce. When the objective of safety from the geotechnical and hydrogeology disciplines is achieved, inherently accomplishing the mine plan should follow suit, or it should significantly minimize the impact by gravity or ground water."

Jan 9, 2018

By H. A. Oliveira, A. Azevedo

Physical and chemical characterization and solid/liquid separation of turbid waters from a river affected by an iron tailing rupture disaster (Gualaxo do Norte River, Brazil) were studied at bench scale. Parameters such as turbidity, pH, surface tension, electrical conductivity, total suspended solids (TSS), particle size distribution (micro- and nanoparticles), and zeta potential were analyzed from samples collected at three different river depths. The results in all samples showed the presence of micro- and nanoparticles, ranging in diameters from 100 nm to 200 μm. Best results for flocculation and settling were obtained at pH 7.5, through an innovative combination of eco-friendly reagents: (i) ferric hydroxide precipitates (10 mg L−1 Fe3+) to sweep (enmesh) the dispersed solids and (ii) gelatinized starch (5 mg L−1 ) to form large flocs. The results showed removals between 90 and 100% of total suspended solids (micro- and nanoparticles), resulting in clear water with residual turbidity < 7 NTU. It is believed that this innovative alternative has a high potential for flocculating and treating the turbid water at Gualaxo do Norte River, assisting the water treatment stations.

By Jun Han

Coal has been mined in the Kailuan mining area for more than 130 years. The remaining reserves consist of, in large part, coals that would have been considered economically unminable or technically not feasible by the previous generations. Some of the current operations have to resort to overmining because the lower seams had been extracted in the past. This paper deals with the feasibility and proper layout of mining roadways of overmining carried out in the No. 5 seam of Qianjiaying coal mine of Kailuan mining area using numerical and physical simulation. FLAC2D was used to investigate the characteristics of stress and displacement in the overburden after extraction of the lower seams. It also analyzed the proper layouts of gateroads in the upper seams, i.e. locating them in the stress-relief zone of the gob so that their stability can be easily maintained. In addition, a two-dimensional physical model was constructed for investigation of damages to the upper seams due to mining of the lower seams. Finally, based on the results of investigations, proper gateroads layout was designed and successful extraction was implemented for panel 1357 in the No.5 seam.

Jan 1, 2009

In a future world of 8.5 billion people in 2035, the Energy Information Administration&apos;s (EIA) projected 50% increase in energy consumption will require true "all of the above" energy resource use from oil, gas, renewables, nuclear, and coal. In particular, coal will continue to be the world&apos;s energy cornerstone, providing more incremental energy over that same time period than any other single fuel. Coal has long been a centerpiece of a low-cost, high-reliability electricity grid. Today there are 1.3 billion people across the globe without access to electricity and 2.7 billion people who do not have clean cooking facilities. The problem is spread across the developing world, but it is particularly severe in sub-Saharan Africa and developing Asia, which together account for 95% of people in energy poverty. Without a commitment to achieve universal energy access it has been estimated that by 2030, there will be an additional 1.5 million premature deaths per year caused by household pollution from burning wood and dung and through a lack of access to clean water, basic sanitation and healthcare. Modern energy sources are essential to meeting these challenges.

Jan 1, 2012

By John D. Shaw

1. Introduction 2. The Hydraulic Mine _ (i ) Development (i i ) Extraction ( i i i ) Transport 3. The Water Circuit 4. Manpower and Results 5. Modifications 6. Conclusions 1. Introduction The Kaiser Resources Ltd. hydraulic coal mine is located in south eastern British Columbia, Canada, at the western end of the Crowsnest Pass, next to the Town of Sparwood. The seam presently being mined is the number 10, known locally as the Balmer seam, which is a high quality coking coal, 50 feet in thickness and of an average inclination of 35 degrees. The mine was designed in the late sixties as a small scale trial unit, and was to use a single monitor unit, working 3 shifts per day on a 5 day per week basis. Experience has proved the method to be so successful as to warrant the expansion of the ancilliary facilities to cater for the increased production. The annual raw coal production from this single monitor unit has risen from 108,988 short tons in 1970 to 942,334 short tons in 1975, with a total mine labour force of about 160 men including the surface de-watering plant, mine supervision and mine administration.

Jan 1, 1977

By Babcock. C. O.

This report presents equations derived from experimental testing to convert borehole pressure cell data from vertical and horizontal cells to the biaxial ground stress changes. While hydraulic pressure cells in boreholes have been in extensive use since 1957, methods of data reduction have been slow to develop. The methods of Sellers (1970) and Bauer et al. (1985), respectively, indicate a linear relationship between cell pressure change and the rock stress change. Lu presented a theory for creep behavior (Babcock et al., 1982). In the present work, in laboratory testing, the logarithm of the cell pressure was related to the stress change in seven elastic materials for a range of Young&apos;s moduli of 3.45 to 85.5 GPa (0.5 to 12.4 x 106 psi). The gage response depends upon the setting pressure of the gage, the gage pressure at any time, the rock properties, and the cross-sensitivity of the gage to transverse loading. The setting pressure of the cell should be proportional to the Young&apos;s modulus of the rock, the absolute stress can be determined by overcoring in strong rock, and the in situ Poisson&apos;s ratio can be estimated in some cases from the cell responses.

Jan 1, 1986