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By Tim O’Neil

More than 5,300 mining professionals from around the world attended the SME Annual Meeting and Exhibit, March 1-3 in Denver, CO. Seventy three technical sessions highlighted innovative technologies and applications for the development of mineral resources. And the exhibit featured 421 companies worldwide and 632 exhibit booths. The 1999 SME Annual Meeting had 10% international attendance. Professionals from outside the United States were guests at the first SME International Reception.

Jan 1, 1999

By A. López-Valdivieso, M. A. Corona-Arroyo, M. Llamas-Bueno

Magnetite (Fe3O4) ore is concentrated by low-magnetic-field drums to recover a magnetite concentrate that is low in silica (SiO2). The presence of SiO2 in the magnetite concentrate for steel production increases the steel processing costs, so a major challenge in magnetic concentration is to lower the SiO2 grade in the Fe concentrate. This work presents studies that were carried out on the removal of SiO2 from the magnetite concentration at the plant scale. Studies were performed with a three 36 × 96″ drum unit processing 46 ton/h of rougher magnetite concentrate. These studies showed that silica appears in the magnetite concentrate by three mechanisms, namely SiO2 entrainment in Fe3O4 chains, heterocoagulation between Fe3O4 and SiO2 particles, and mineral locking of SiO2 to Fe3O4. The SiO2 entrainment mechanism had the highest contribution (75%) to the SiO2 recovered in the Fe concentrate. Electrokinetic studies on Fe3O4 and SiO2 showed that heterocoagulation occurs because of the low negative zeta potential of the minerals at the pH of the plant slurry. This study also showed that a high percentage of ultrafine size SiO2 particles trapped in Fe3O4 agglomerates was not removed by the dilution water for the slurry fed to the drum. To lower the SiO2 recovery in the drum magnetic concentration process, work should be directed towards the removal of trapped SiO2 in Fe3O4 agglomerates.

By Jean-Marie Fecteau

The gold mine sector is presently facing low gold prices as well as technological challenges. Its competitiveness and survival will depend on new mining methods and equipment to improve ore extraction. In 1999, Natural Resources Canada has invested new funds over a period of three years at CANMET?s Experimental Mine to establish the Narrow-Vein Mining Project. A team of engineers and researchers specialised in mining, mechanics and electronics engineering are working to meet the critical need of ore-extraction technology. CANMET?s program in mechanisation and automation for narrow vein mining had, prior to 1999, realised several important achievements, many in co-operation with a consortium of mining companies (Soredem). The investment of new funds in this area will contribute to develop technologies to improve the productivity, as well as health and safety conditions of the narrow vein mining industry. Several important impacts of this project will be monitored. Specifically, a database of methods and equipment used in narrow vein mining is being developed. A key thrust is to identify operators? needs with respect to the development and automation of mining methods and equipment. Based on those needs, research and development projects will be created. The main problems identified following meetings with mine operators are described with a few elements of solution and the Web site created for the broadcast of the results is presented.

Oct 1, 2001

By K. Takahashi

Generally speaking, wastewater coming from the metallurgical process for recovering precious metal contains precious metals such as gold (Au), platinum (Pt), palladium (Pd), Silver (Ag), etc., which concentration is about 10 mg/L. In addition, there are other metals such as copper (Cu), iron (Fe), which concentration varies from several mg/L to more than 10,000 mg/L. It should be noted that the concentration of metals in wastewater is relatively high, considering the fact that these metals of similar concentration can be found in ores. However, most of these valuable metals are not treated, due to the high processing cost and technical problems. Within this frame, the authors put forward a new process that includes neutralization/reduction, precipitation and fusion. The idea is to recover and recycle Au, Ag, and Pd metals as well as protecting the environment by saving the resources. It was found that this new process was able to recover more than 90% of Au, Ag and Pd.

Jan 1, 2014

By Eti Purwaningsih, Widi Astuti, Erik Prasetyo

Selective-reductive leaching of manganese from low-grade manganese ore using tannic acid as a reductant in acidic media was demonstrated by XRD, SEM-EDX characterization, and batch leaching studies at room temperature. The pH change in the liquid phase before and after leaching revealed that selectivity of manganese over iron was due to the hydrolysis of iron. The acidity in the liquid phase during leaching was dictated by two mechanisms: proton-consuming reaction (manganese oxide reduction by tannic acid) and proton-producing reaction (ferric ion reduction by tannic acid to produce ferrous ion). Based on the leaching studies, the more prevalent reaction between these two was determined by initial leaching conditions: tannic acid concentration, sulfuric acid concentration, liquid-solid ratio, temperatures, and agitation time. Kinetic studies revealed that maximum recovery was attained within 6-h agitation, which indicated a product layer diffusion process.

By Eti Purwaningsih, Widi Astuti, Erik Prasetyo

Selective-reductive leaching of manganese from low-grade manganese ore using tannic acid as a reductant in acidic media was demonstrated by XRD, SEM-EDX characterization, and batch leaching studies at room temperature. The pH change in the liquid phase before and after leaching revealed that selectivity of manganese over iron was due to the hydrolysis of iron. The acidity in the liquid phase during leaching was dictated by two mechanisms: proton-consuming reaction (manganese oxide reduction by tannic acid) and proton-producing reaction (ferric ion reduction by tannic acid to produce ferrous ion). Based on the leaching studies, the more prevalent reaction between these two was determined by initial leaching conditions: tannic acid concentration, sulfuric acid concentration, liquid-solid ratio, temperatures, and agitation time. Kinetic studies revealed that maximum recovery was attained within 6-h agitation, which indicated a product layer diffusion process.

By P. A. Cox

The purpose of the initial research performed under this contract was to determine the margins of safety in explosion-proof (XP) enclosures, which were designed and certified according to the current schedule (Schedule 2G). Results from this work provide baseline data on the current schedule, from which a new schedule can be formulated to give equal or greater levels of safety. Results and discoveries in the initial work led to an expansion of the contract to cover, additionally, weld quality in enclosure fabrication, reliability of enclosures with windows and lenses, and performance tests for enclosure qualification. Finite element calculations and hydrostatic tests revealed wide variations in the margins of safety in the enclosures studied; however, only one enclosure had a safety factor which was less than one. Results from a weld quality survey led to the recommendation of AWS Welding Standard D14.4 for the fabrication of XP enclosures. Based on other work, accelerated aging tests were recommended for qualifying plastics and adhesives that are used in some enclosures, and a Structural Performance Test was developed to test enclosure strength for a minimum static pressure of 150 psig.

Jan 1, 1982

Early American history is filled with records of the search for and extraction of minerals-a Northwest passage to the treasures of the Indies-an overland route to the goldfields of California. Mining and its associated minerals industry have heralded advancing civilization throughout the ages. The two basic resources on which we all depend for our food, clothing, shelter, and other comforts are agriculture and minerals. Our endowment and how we use it; the spirit and industriousness of our people; our form of social organization all converge to make up our standard of living-our way of life.

Jan 1, 2012

By NORA Mining Sector Council

The National Occupational Research Agenda (NORA) is a partnership program to stimulate innovative research and workplace interventions. In combination with other initiatives, the products of this program are expected to reduce the occurrence of injuries and illnesses at work. Unveiled in 1996, NORA has become a research framework for the National Institute for Occupational Safety and Health (NIOSH) and the United States. Diverse parties collaborate to identify the most critical issues in workplace safety and health and develop research objectives for addressing those issues. NORA entered its third decade in 2016 with an enhanced structure. The 10 sectors formed for the second decade will continue to prioritize occupational safety and health research by major areas of the U.S. economy. In addition, NORA’s seven cross-sectors will continue to focus on the major health and safety issues affecting the U.S. working population. While NIOSH serves as the steward to move this effort forward, it is truly a national effort. NORA is carried out through councils comprised of members with many diverse interests that are developing and implementing research agendas for the occupational safety and health community over the third decade (2016-2026) of NORA. Councils address objectives through information exchange, partnership building, and enhanced dissemination and implementation of evidenced-based solutions. NORA groups industries into 10 sectors using North American Industry Classification System (NAICS) codes. The Mining Sector encompasses NAICS code grouping 21xxxx where “xxxx” represents the different subcodes of the mining “21” classification. Mining encompasses the extraction of solid mineral and mineral-like substances from their place in the Earth’s crust and supplies them to processing industries that produce economically valuable materials. It does not include oil and gas extraction. The Mine Safety and Health Administration, MSHA separates mining into coal, underground and surface, and metal and nonmetal, underground and surface.

Feb 1, 2024

By Jie Li

Series of carbon compounds as anode materials were prepared for super lithium ion capacitor using graphite and active carbon (AC) as raw materials. Their electrochemical properties were investigated by constant current charge-discharge test. The results showed that the compound anode had good capacitive performance as well as Li-ion battery performance. The potential of the capacitor could be as high as 3.5V vs Li/Li+ when compared with 2.5V vs Li/Li+ in the AC-AC capacitor, accordingly, the energy density increased from 21.7Wh/kg to 40.3Wh/kg. The compound anode also had excellent rate performance that as the current density increasing from 0.1A/g to 1A/g,the capacitance decreased only 1.3F/g, and good cycle performance that the capacitance holding remained 96.7% after 10 times cycles even at the highest potential of 3.5 V vs Li/Li+.

Jan 1, 2009

By Graham Holmes, John Starkey

"The Kinross Kubaka Project is a gold mine located in the Russian Far East. The grinding circuit, comprised of a 6.1 m diameter x 2.74 m long SAG mill and a 4.1 m diameter x 5.5 m long secondary ball mill in closed circuit with cyclones, was built using SAG Power Index and Bond Ball Mill Work Index testing to determine the grinding energy requirements. Extremely cold climatic conditions and the need to keep heated space and capital costs to a minimum, dictated a grinding circuit with no in-circuit crusher and no conveyors external to the mill. High energy requirements for both the SAG mill and the ball mill were correctly predicted and have allowed grinding production tonnage forecasts to be met. Design test data and production results are given.INTRODUCTIONIn 1995 Davy International Canada, now Kvaerner Metals E & C, was commissioned as the Engineer and Project Manager for the Omolon Gold Mining Company, to design and construct a gold extraction plant for the Kubaka gold deposit, located in the Russian Far East. This deposit had been studied extensively in Russia during the exploration phase and a Feasibility Study was completed in 1993 by Kilborn who visited the site twice during that year to inspect facilities and to take metallurgical test samples. More samples were taken in 1995 to check ore hardness variability, as part of the final design program by Davy.The client’s objective in designing the Kubaka grinding circuit was to achieve design tonnage at all times, even when milling the hardest ore zones in the deposit. Since the samples taken in 1993 were taken as composite samples, it was necessary to take additional samples in 1995 to determine the extent of the variability. Six samples were sent to Canada for SAG Power Index (SPI) testing. Five of these were combined as a composite open pit sample, while the sixth sample was taken from the site adits as a composite sample to represent undergound ore. These two composite samples were tested to determine the MacPherson Autogenous Work Index for comparison with the SPI values."

Jan 1, 2001

By David Conover

Technological advancements in electronic sensors and mine-wide monitoring systems have improved remote monitoring and analysis of underground mining information. The effective use of . these systems for ground control applications, however, remains a challenge facing the mining industry. The U.S. Department of Interior, Bureau of Mines is conducting research, utilizing real-time acquisition of rock mechanics data, to provide mine operators the means to rapidly identify and manage potentially hazardous ground conditions. The Bureau has installed a remote monitoring network in a Colorado coal mine to record Pressures from instruments installed in the roof and pi1lars of gateroads and from transducers on shield-legs along the face. The field data are being monitored at the Denver Research Center, 150 mi from the mine. A computer at the Center analyzes the field data and generates graphic displays, which permit detailed examination of mine-wide ground conditions in real-time. For the first time, Bureau researchers are able to perform real-time monitoring and analysis of rock mechanics data while mining is in progress. The data collection and display capabilities of the system were effectively used to identify and evaluate face stability problems at the mine.

Jan 1, 1990

By E. D. Doney

The Kerr-McGee Coal Corporation's Galatia Mine's first longwall mining system was implemented on May 3; 1989. Start-up of the longwall face represnted the successful conclusion of an effort begun nearly four years earlier. This paper-presents a case history of the processes that led to the longwall's implementation, and the subsequent mining of the first 7,900 foot long panel.

Jan 1, 1990

By Frank E. Cash, John A. Johnson

"INTRODUCTION The operators of the Lake Superior district iron-ore mines have made tremendous progress in the past 25 years in the transportation of broken ore from the working places to the surface. This progress has paid divi¬dends in increased production and in lower accident-frequency rates. The trend has been toward more efficient use of mechanical and electrical power and abolishment of many of the backbraking tasks formerly required of min¬ers and trammers.ScopeTransportation of iron ore as described in this paper covers (1) movement from the working place to ore raises by scrapers, shaker,conveyors, and belt conveyors, and, loading underground cars from chutes or-by scraping from loading drifts; (2) underground haulage, which includes underground cars trains, locomotives, and tracks; (3) shaft station's and hoisting shafts, which. Includes dumping cars, storage-pockets; auxiliary storage trenches, and shafts; (4) hoisting, which consists of skips, cages and hoists; and (5) head frames, loading into railroad cars, and stock-pile haulage.The 19 underground iron-ore mines discussed in this paper, situated in the Menominee, Marquette, Gogebic, Guyana, Mesabi, and Vermilion iron ranges of Michigan, Wisconsin, and Minnesota., shipped about 9,000,000 tons of iron ore in 1945, which constituted 56 percent of the underground iron ore taken from the Lake Superior district."

Nov 1, 1947

By Jacques B. Wertz

Recurring movements remotely connected with the Murray fracture zone and the San Andreas fault complex, together with the slow northwestward drift affecting the Baja California peninsula, could progressively have accentuated the tensional situation already connected with the anticlinorium in southern Arizona. From the fragmentary data gathered on the Texas lineament, it appears that a very mild curvature, concave to the northeast, may be present along this belt throughout Arizona. Those localities where the successive changes in direc¬tion of the strands of the lineament belt seem to occur do generally coincide with intersections of both north-northwestern and northeastern breaks. It is along the outward, southern fringe of the belt (at such structural centers like Bisbee, Baboquivari, Ajo) that the greatest impact of regional movements could be expected to have occurred through tangential-torsional stresses. Although it si accepted that the north-northwestern and more particu¬larly the northeastern fractures in Southeast Arizona are propitious to or partially responsible for mineralization, it seems undeniable that the Texas lineament belt must have greatly increased the potentialities for ore throughout the Arizona copper province. While intrusive bodies occur near major intersections, with the Texas lineament belt as a common denominator, it seems, the ore deposits are to be found close to one of the intrusive stocks, varying in distance from contiguity (Bisbee) to one or two miles away (Silver Bell orebodies).

Jan 1, 1970

By Paul M. Godlewski, Joseph P. Gildner, David S. McAllister

With construction underway on the 22.5 km (14 mile) Initial Segment of the Link Light Rail transit system in Seattle (including the one-mile EPB-driven running tunnels and mined station at Beacon Hill), the Sound Transit Board on May 20, 2004 voted on selection of a preferred route for an approximately eight-mile extension northwards from the central business district to Northgate, and authorized immediate start of advanced conceptual/preliminary engineering and geotechnical exploration programs scheduled to be completed in Spring 2005. The extension includes approximately914 m (30,000) route-feet of bored running tunnels, a mined station with platform level approximately 60 m (200 ft) below grade, three (possibly four) cut-and-cover stations and a cut-and-cover cross-over structure, as well as an aerial terminal station at Northgate and other line-section below-grade and aerial structures. All tunneling will be in glacial soils.

Jan 1, 2005

By Y. M. Jiang

A users friendly PC Computer Program has been developed to implement a systematic design of the powered support. The required input data are: (1) thickness, RQD, and compressive strength of the immediate roof; (2) mining height; and (3) type, thickness, and tensile strength of the main roof. Several important parameters for support selection under a given geological condition are generated through the implementation of the program, including type of support most favorable for the geologic condition, minimum inclination angle of the legs with respect to the horizontal axis, suitable setting load ratio of the front to rear leg for the 4-leg supports, optimum setting load, and support capacity.

Jan 1, 1989

Laboratory induced polarization measurements were made on representative samples of concentrated sulphide ores from three environments in New South Wales Comparisons were made with the membrane polarization exhibited by an argillaceous sandstone. The sulphide samples showed a strong polarization effect, the magmtude of whIch depended directly on the conductivity of tlIe pore electrolyte.

Jan 1, 1969

By P Shen, K Hattori, H Pan, E Seitmuratova

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Ore-bearing intrusions in the Central Asian Orogenic Belt (CAOB) were examined from nine mines: Boshekul, Nurkazgan, Kounrad, Borly, Aktogai, Koksai, Baogutu, Tuwu and Erdenet. The intrusions are diorite, granodiorite and tonalite with SiO2 contents ranging from 58 to 75 wt per cent, and show mildly fractionated rare earth elements (REE) ([LREE]N/[HREE]N = 2.7–4.7) – light REE and heavy REE – and varying Eu anomalies ([Eu]/[Eu]* = 0.58–1.4). The ratios of Sr/Y vary from 7.9 to 115 and the contents of Y from 4.6 to 23.9 ppm. The parental magmas of the intrusions are intrinsically oxidised. Zircon grains in the ore-bearing rocks from large- and intermediate-sized porphyry Cu deposits show high Ce4+/Ce3+ ratios characterised by 65–422 at Boshekul (>4.1 Mt Cu), 76–480 at Kounrad (>4.8 Mt Cu), 90–280 at Aktogai (>12 Mt Cu), 80–250 at Erdenet (>11 Mt Cu) 74–370 at Nurkazgan (>3.9 Mt Cu), 100–210 at Koksai (>1.6 Mt Cu), and 71–340 at Tuwu (~2.0 Mt Cu). In two small deposits, the ore-bearing rocks display low values of Ce4+/Ce3+; Borly (0.6 Mt Cu) ranging from 28 to 158, and Baogutu (0.6 Mt Cu) from 29 to 113. The Ce4+/Ce3+ ratio of 120 distinguishes large intermediate-size deposits from small-size deposits. This information is potentially useful in exploration for porphyry Cu deposits in the belt.CITATION:Shen, P, Hattori, K, Pan, H, Jackson, S and Seitmuratova, E, 2015. Granitoids associated with porphyry Cu deposits in the Central Asian Orogenic Belt – characteristics and oxygen fugacity, in Proceedings PACRIM 2015 Congress, pp 377–382 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By Maurice Bottiau

The recent evolution of the piling market clearly shows a growing demand for screw piles with soil displacement. The recently developed Omega Screw pile ful-fill these new expectations, combining the advantages of vibration-free systems and the behaviour of a displacement pile. The paper describes recent experience and new applications with this very promissing pile. Full-scale load tests were carried out in different countries as U.K. or Sweden. A very attractive and innovative piled embankment is also described, using geogrids in order to transfer the loads from the superstructure to non-reinforced Omega-piles.

Jan 1, 1996