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By Tom Gonzales

At San Manuel, AZ, Magma Metals Co. operates an Outokumpu flash furnace, four Peirce-Smith converters and two anode casting wheels that are supported by six anode vessels. Process gasses from the flash furnace and converters are treated in a two-train/ double-contact sulfuric acid plant. The plant captures 98% of the sulfur. A new flash furnace was commissioned in July 1988. It has since processed more than 2.7 Mt (3 million st) of sulfide concentrate without a major rebuild. The company has gained unique experience in the operation of the flash furnace at high oxygen enrichments with low off-gas dust loadings. New procedures have been developed to maintain secondary material generation at equilibrium and for maintaining metallurgical control of operating parameters. Process flow description At Magma's San Manuel plant, concentrates and other copper-bearing material are blended and conveyed from two separate areas of the plant to three 420 t (465 st) capacity wet charge bins located above the rotary dryer. Flash furnace silica flux is conveyed to a 227-t (250-st) capacity fine flux bin located adjacent to the wet charge bins. The concentrate and flux are blended in controlled amounts and fed into a 168-t/ h (185-stph) gas-fired rotary dryer. The wet charge enters the dryer at 8% moisture and is dried to 0.2% moisture. The dried charge is pneumatically conveyed to a 580-t/h (640-stph) dry charge bin located above the flash furnace. Flash furnace charge is drawn from the bin by two drag conveyors at a concentrate feed rate of 145 t/h (160 stph). The charge is mixed with enriched combustion air and injected into the furnace reaction shaft. In the reaction shaft, the charge is oxidized to form matte, slag and a rich SO, off-gas.

Jan 1, 1992

By Wing G. Agnew

It is thought that a brief description of the unique mining and milling procedure at the Doyle nine may be interesting to those engaged in small-scale operations at old mines or in working new ore body adjacent to old workings. It also shows what can be done with r. small capital outlay in working a zinc-lead mine on a small scale; as the operation herein described was begun 3 years ago with four men and it now employs 17 men. The original idea was to mine out any ore left around the edges of some old stones above the water level and to rob pillars after an old stope became filled with waste and tailings. This has been done, and the procedure is still being followed; at the same time a paying lead is being mined toward an area in which churn-drill holes have shown ore. Also, preparations are now being made to do some pumping.

Jan 1, 1936

By Linneas Laage, Thomas Weber, William Pomroy

"Underground mine fires can significantly influence mine ventilation airstreams, in some cases throttling or even reversing airflows. As a result, the performance of a metal and nonmetal mine stench fire warning system, which depends on the ventilation to carry the vital warning signal, under fire conditions is different from performance under nonfire conditions. The safety of underground miners can be jeopardized if the warning signal is delayed. This Bureau of Mines report describes research to investigate fire and stench warning system interactions. A computer model is presented that permits quantitative analysis of stench warning signal delays as a function of fire location and intensity. The results of a case study involving computer simulations of stench distribution in a hypothetical mine network subject to various fire exposures are also discussed. This case study illustrates a technique for identifying the areas within a mine that are subject to unacceptable warning signal delays, thereby enabling preemptive action by mine personnel, such as redeployment of stench injectors. INTRODUCTIONFires are an ever-present threat to the safety of underground miners. Since the smoke and toxic gas produced by a mine fire can be spread rapidly by the mine's ventilation system, mine evacuation must be accomplished as quickly as possible in the event of fire. In metal and nonmetal mines, the most common means of passing the fire warning signal to each miner is the stench system. The typical stench system utilizes ethyl mercaptan, a highly odoriferous organic compound, injected on the surface into the compressed and/or ventilation airstreams. Upon smelling the stench, workers evacuate the mine according to an emergency preplan.Although the stench system has been used successfully for over 60 yr, it has several serious shortcomings, owing to certain chemical properties of ethyl mercaptan and to certain performance characteristics and limitations of present injection systems.Recent Bureau research succeeded in upgrading the overall safety and effectiveness of the stench system through the use of a superior stench odorant and the development of improved stench injection equipment (1).4 This research has also investigated a specialized computer simulation model capable of calculating the precise concentration of stench in any mine ventilation network branch at any time after stench release (2). An adaptation of the computer model now enables the analysis of stench system and ventilation system interactions under the influence of a mine fire."

Jan 1, 1987

By AIME AIME

THE Engineering Education Committee of the Institute convened at the Engineering Societies Building on Feb. 18, .1929, with. E. A. Holbrook, dean of the Schools of Mines and Engineering, University of Pittsburgh, in the chair. STATISTICAL' STUDY OF STUDENTS IN MINING The first paper, a statistical study of the students enrolled in courses leading to a mining degree in 40 institutions, was presented by H. D. Keiser,, assistant editor of the Engineering and Mining Journal; who gave a brief outline of an article he was about to publish in ?that journal?. The complete article appears in the issue for March 30; 1929: To avoid repetition the results are summarized as follows: A request was sent to 42 institutions which give courses in mining' for the number of students enrolled as freshmen; sophomores; juniors, seniors and special students in mining for the years 1925-26, 1926-27, 1927-28, 1928-29. Two of these colleges replied that there were no students in mining. Students' enrolled in courses in metallurgy, geology and engineering, other than mining, were excluded from the statistics:. The statistics received were arranged in, four groups, according to the completeness of the information. One complete group of 25 institutions 'shows as follows:

Jan 1, 1929

Systemic process mineralogy study on Baerbulawu refractory hematite ore in Kazakhstan has been carried out. The ore contains Fe 41.34%, and 87.26 % of which exists in hematite. Most hema-tite occurs as fine or ultrafine grains and its average size is only 0.015mm. The gangue is mainly composed of quartz, mica, chlorite, kaolinite and other clay minerals. The liberation of hematite is only 66% when the ore is grinded to 75% ?0.074mm, while part of gangue is already liberated from hematite under this grinding condition, so these gangue can be cast away by magnetic separation in advance. Hematite will not liberate completely from gangue untill grinding fineness reaches 86% ?0.038mm, at the same time, free particles of ultrafine hematite tend to coagulate randomly with quartz and clay minerals, so appropriate dispersant is necessary to pre-vent hematite and clay minerals from coagulation. Based on the process mineralogy research, final technology flowsheet is high-intensity magnetic separation by coarse grinding?rough magnetic concentrate regrinding?inverse flotation, and an ideal index is achieved. The yield of final iron concentrate is 43.46%, and its grade and recovery are 66.76% and 70.55% respectively. The research result is also useful to other similar iron ores.

Jan 1, 2014

By Albert L. Toenges, Theodore R. Jolley

"INTRODUCTION The construction of frame houses (fig. 1) in recent years instead of the conventional sod hut (igloo) (fig. 2) by the Eskimos in the villages along the Arctic Ocean has increased the demand for fuel in these villages. The frame houses, which are not insulated against extreme cold and are difficult to heat, are equipped with Goal stoves. The well-insulated sod huts were heated comfortably with whale-oil stoves. In some years whaling is Door, consequently there is a demand for solid fuel.The Eskimo villages usually are on the sand spits at the mouths of rivers and points of land near the best fishing and hunting grounds. These narrow necks of land usually are sand bars that are not underlain with coal, and coal must be transported to the villages. Lack of development of coal deposits in the Arctic has made it necessary to import coal from the States, generally from 'Washington, to supply these villages. This coal is imported by boat and is received once a year. Its cost is, high, and development of coal deposits in the Arctic to supply these native villages should result in a considerable saving to the Government-operated schools and hospitals as well as to the natives.Early traders attempted to establish coaling stations in the Arctic, and the Eskimos generally know where the coal deposits are situated. A. reconnaissance of a number of deposits in the Arctic was made in the summer of 1946 by engineers of the Coal Division, Fuels and Explosives Branch, Bureau of Mines, and this report describes the areas investigated and suggests plans for the development of some of these deposits."

Dec 1, 1947

By Wen Tao Liu, Tong Tian, Fu Sheng Niu, Xiu Man Liang

In order to address the difficulty of accurate segmentation of froth images of different sizes, a method of froth image segmentation based on highlight correction and parameter adaptation is proposed. First, a machine vision system on a single-cell flotation machine is built to collect froth images. Homomorphic filtering is used to improve the uneven brightness and shadow of the images. Fuzzy c-means (FCM) clustering is then utilized to classify similar highlights that belong to the same froth. After Otsu threshold segmentation, a parameter-adaptive morphological operation is used to extract the marker points and edge bands and correct the froth edges in the original image. Finally, the modified image is filtered by morphological reconstruction, and the highlight mark is used as the local minimum point for watershed segmentation. Three sizes of froth images are segmented in comparative experiments. The results show that the proposed method is suitable for the segmentation of froth images of different sizes. The position of the extracted segmentation line is close to reality, with average over-segmentation and under-segmentation rates for froth images of 2.6% and 6.8%, respectively. The froth image segmentation performance is stronger than that of the other methods examined.

By Thierry Bernard

This case study shows how a unique combination of field measurements and advanced technologies allowed blasters designing, loading and firing an incredibly challenging quarry blast.

Jan 1, 2015

This article updates the status of fatalities occurring in both coal and metal/nonmetal mines from January through December of 2001. Based on preliminary accident reports, as of December 31, 2001, seventy-two fatalities have occurred at coal and metal/ nonmetal mining operations. During this period, forty-two fatalities occurred at coal operations and thirty fatalities occurred at metal/nonmetal operations. Ignition or explosion of gas or dust and fall of roof were the most frequent accident classifications in coal and powered haulage fatalities were the most frequent accident classification in metal/nonmetal.

Jan 1, 2002

By Ron Lutz

In today’s world, production is the name of the game. We are all in business to make money. In the Quarrying and Mining industry the same holds true. The primary goal is to develop the best drilling and blasting program available to maintain uniform fragmentation to maximize production. Also we want to maintain drilling and blasting costs and minimize escalators. This paper is intended to discuss ways for all parties (quarry’s, blast service and drill companies) to attain this through understanding what can be done to help blasthole drilling and production. Blast designs and seminar’s emphasize the accuracy of drilling to produce better fragmentation. Blast design must also include basic concepts in the drilling process. The type of drill to be used for example whether it is a crawler or truck mount, top hammer or down the hole is important. Quarry operators have a role to play as well. They hold the key to the production of drilling. What the customer does or does not do has a direct effect financially to the drilling. The phrase of pay me now or pay me latter comes to mind. This paper will explore the detail of planning that is required by the quarry and/or blast service companies before a single hole is drilled. The drill must be able to meet the production need of the operation. The type of drill available and what can and cannot be done. The drill cost must be competitive. This paper will touch on comparison drill costs from 1967 to 1999.

Jan 1, 2000

By T. H. Jeffers

Significant amounts of cobalt are present in readily accessible spent copper leach solutions. The Bureau of Mines investigated the feasibility of extracting cobalt from these solutions in a multiple-compartment ion-exchange (MCIX) column. The effects of aqueous flow rate, resin flow rate, column height, and compartment height on cobalt extraction were determined. Cobalt extractions of 92 pct or higher were achieved at solution flow rates of up to 5.5 gpm/ft of column cross-sectional area and an aqueous-to-resin flow ratio of 40:1. Overall cobalt extraction increased as the column height increased, but cobalt extraction per unit of length was more efficient in 8-and 12-ftco1umns than in an 18-ft column. Solvent extraction procedures were utilized to purify and concentrate the MCIX column eluates and produce a cobalt sulfate solution containing 70 to 80 giL Co. Metallic cathodes containing over 99 pct Co were e1ectrowon from this solution. Zinc, nickel, and copper byproducts were also recovered during processing of the ion-exchange eluates. Estimated total capital cost for a commercial-scale 10,000 gpm of a spent leach solution containing 26 million. With credits for zinc, nickel, and copper estimated net operating cost was $9.36/lb Co.

Jan 1, 1987

By K. G. Gorling, S. J. Wallden, N. B. Lindvall

It is the policy of The Metollurgical Society to provide, in the TRANSACTIONS OF THE METALLURGICAL SOCIETY OF AIME, a prompt and accurate medium for publication of reports of significant new research in both the scientific and engineering aspects of metallurgy. Papers submitted to the Society are judged by competent reviewers according to established criteria for technical merit, accuracy, originality, and presentation. STAFF: Editorial Director, Rixford A. Beals; Associate Editor, James J. Burke; Assistants, L. Capria and R. K. Larkin. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: A. W. Thornton, Choirmon; Dennis Carney, John Chipman, J. C. Fulton, J. H. Hollomon, H. tl. Kellogg, A. E. Lee, R. Maddin, J. D. Sullivan, and O. Swan. Review and selection of manuscripts is under the supervision of the following Publications Committees: Extractive Metallurgy Division T. B. King. Cha~rmon; S. J. Dickenson, R. P. Hermsdorf, R. Schuhmann, Jr.. and P. T. Stroup. Institute of Metals Division: Robert Maddin, Chairman. F. Lincoln Vogel, Jr., Vice-chairman, W. A. Backofen, R. W. Balluffi, J. H. Bechtold, M. B. Bever, R. S. Busk, C. G. Goetzel, Paul Gordon, C. D. Graham. Jr., Robert F. Hehe-mann, R. I. Jaffee, F. E. Jaumot, Jr., lrving R. Kramer, A. J. Leno, Horold Margolin, C. J. McHorgue, Russell A. Meussner, J. 6. Newkirk, H. W. Paxton, G. E. Pell~ssier, I. S. Servi, Alan U. Seybolt, A. J. Sholer, and Sack Wahsburn. Iron and Steel Division: J. C. Fulton, Chairman; T. B King, F. C. Langenberg, W. O. Philbrook, and T. B. Winkler. Published bimonthly by the American Institute of Mining Metallurgical and Petroleum Engineers Inc., 29 West 39th Street, New York 18, N. Y. Telephonne pennsylvania 6-9220.Petroleum Subscription Engineers$20 per year for non-AIME members in United States and North South and Central 6-9220.SubscriptionAmerica $25 toreign; $5 for AIME members. Single copies, $4.00, iinalo copies Southfpr;ign,andCentral $5 00. The AIME 'is $25not responsible for any statement made or opinion expressed in its publications Copyright 1958 1958 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . Registered coble address, AIME New York . . . Indexed in Engineering Index, Industrial Arts Index, ...and Chemical Abstracts . . . Application for second class mail privileges IS pending at New Yark, N. Y. Volume 212, Number 2.

Jan 1, 1959

By Guoqiang Lv, Xi Yang, Wenhui Ma

Cast multicrystalline silicon ingots are widely used in photovoltaic manufacturing. A key issue to achieve high solar cell efficiencies is to attain an optimized temperature field during directional solidification (DS) process. This paper reports numerical investigation of multicrystalline silicon (mc-Si) ingot production using two major types of DS furnace. Specific examination is made on thermal distribution, interface shape and stress field. Evaluation is performed for the applicability of thermal system design to reduce thermal stress, improve crystal quality and enhance energy efficiency. The effects of procedure parameters and geometric configuration on temperature distribution are discussed as well to provide the viable solutions for systems optimization.

Jan 1, 2015

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 J D. Grobler

In the heavy minerals industry wet high intensity magnetic separators (WHIMS) are widely applied for primary magnetic separation of magnetic minerals and non-magnetic minerals. This piece of equipment is well known for its robustness to handle a wide range of feed conditions and still produce stable product qualities and yields. A heavy mineral production plant aimed to increase production through their WHIMS plant containing 11 duties and 26 units. Instead of adding new units an alternative approach was followed to firstly maximise the efficiency of the current circuit and secondly to consider possible reconfiguration of the circuit to produce additional product tons for minimal capital investment. In order to characterise the current circuit’s efficiency, identify pockets of excellence and determine the areas for improvement the whole circuit was surveyed several times and mineral mass balances were drawn up.This paper aims to: discuss the modelling process of the WHIMS circuit,explain the calibration and validation process followed to ensure the accuracy, anddemonstrate the sensitivity analysis performed on the different options. From this analysis an efficiency criteria was developed to compare different circuit configurations that enabled the production plant personnel to make an informed decision on the way forward.

Oct 5, 2011

By Thomas Marcher

Stanford Linear Accelerator Center (SLAC) is located in Menlo Park, CA. In order to allow for enhanced experiments, the current facilities required expansion. Tunnels were excavated through very weak sedimentary rock interspersed with uncemented zones (Ladera Sandstone) employing the principles of the NATM. The overburden var-ied from 10 to 80 feet. The paper addresses the characterization of Ladera Sandstone that can exhibit the properties of dense sand and weak rock. The paper focuses on the challenges that were encountered during the NATM initial support design and the construction phase including the geotechnical instrumentation, monitoring and design verification process in particular the excavation of the junction between access tunnel and the FEH cavern (49 ft wide by 32 ft high).

By Alexander E. Morrow

Oxygen breathing apparatus for use in mines was introduced to the United States in 1907. Despite their intended purpose of safeguarding lives, the apparatus led to the deaths of many men because of inherent or developed defects in the equipment, lack of training,, physical shortcomings of wearers, and improper procedures. The Bureau of Mines pioneered in research and training to curb logs of life among users of such apparatus and promoted development of safer equipment and procedures. As a consequence, deaths have been far less frequent. In 1944 the Bureau issued Information Circular 7279, Loss of Life Among Wearers of Oxygen Breathing Apparatus. That publication listed the case histories of 26 deaths that had occurred since the introduction of such equipment to American mining. The author, the late G. W. Grove,3/ asserted that further loss of life could be avoided if good equipment were used, teams were properly trained, and the basic principles of safe procedure were followed. This publication is a sequel to I.C. 7279 and contains information on eight deaths among wearers of oxygen breathing apparatus that were overlooked in the original compilation. It also describes the single death that occurred since I.C. 7279 was published.

Jan 1, 1959

By M. Nete

Qualitative analysis of three mineral samples from northern Mozambique was accomplished by X-ray diffraction (XRD), microscopy, scintillation, and magnetic determination. Chemical characterization was accomplished using ICP-OES and pressed powder XRF after dissolution using microwave-assisted digestion and flux fusion. The samples consisted of a mixture of minerals with tantalite as the major component, with minor amounts of microlite, quartz, mica, accessory garnet, and tourmaline. Incomplete dissolution was obtained using microwave digestion, with maximum recoveries of 90.25 ± 0.06% and 88.90 ± 0.04% for Nb2O5 and Ta2O5 respectively. Complete dissolution using Li2B4O7 resulted in recoveries of 98.5 ±0.2% Nb2O5 and 100.4 ± 0.3% Ta2O5.

Jan 1, 2012

By Verya Nasri, Agustin Rey

Once completed, the Montreal Réseau Express Métropolitain (REM) will be the fourth largest automated transportation system in the world. The REM represents construction costs of approximately 7.0 billion Canadian dollars. The project consists of 67 km of twin tracks over four branches connected to downtown Montreal. The project includes 26 stations with 3 underground stations in downtown Montreal. One of the underground stations was built using the NATM method with thin permanent shotcrete initial and final liners separated by a sprayed on waterproofing membrane. The 2 other underground stations were built with the cut and cover approach including one using permanent secant pile wall with permanent walers and struts as the support of excavation and the final perimeter wall of the station. The project also includes the rehabilitation and enlargement of the Mont Royal Tunnel. This 100-year-old double track tunnel is about 5 km long. The REM also consists of 3.6 km new TBM tunnel connecting downtown to the Montreal International Airport through saturated soft ground and karstic rock. By the time of RETC, the construction of REM underground structures will be completed. This paper presents the design and construction aspects of the underground structures of this mega project.

Jun 13, 2023

By A. Ayoubian, V. Nasri

This Tunnel Connection project will include construction of two short tunnels to connect the existing subway tunnels (Red and Blue lines) in the northern loop area of downtown Chicago through a new station. The Southeast Tunnel will connect the Red Line to the new station below the intersection of State and Washington Streets and the Northwest Tunnel will connect the Blue Line to the new station below the intersection of Dearborn and Randolph Streets. The connection tunnels are located in a very dense urban area of downtown Chicago and under several important historical buildings. Both tunnels are curved at the intersections and located at a depth of about 7.5 m below ground surface in saturated soft clay with an average undrained shear strength of approximately 25 kPa. The design calls for minimizing surface disruption and ground displacement while maintaining normal operation of the existing subways during the construction of the connections tunnels. This paper presents mining and cut and cover tunneling alternatives for the project.

Jan 1, 2007