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By C. G. Anderson

Industrially proven and applied nitrogen species catalyzed (i.e. NSC) acidic pressure leaching has been utilized to treat a number of ores, concentrates and recycled materials. This versatile technology offers many advantages including low temperatures, low pressures, low capital costs, low operating costs, faster throughput and less costly materials of construction than conventional pressure oxidation. This paper will elucidate the application of this technology for production of gold, silver, palladium, rhodium, zinc, germanium, gallium, cobalt, copper and nickel. Recycled material applications will also be elucidated. In addition, details of an application for treatment of a refractory chalcopyrite copper and gold bearing ore will be presented and pertinent economics discussed.

Jan 1, 2004

By Rejean Gagnon, Fernand Rochefort

"Haulage costs, in most operations, represent a large portion of total cost. Quebec Cartier Mining Company came to the conclusion t hat an electric trolley assist providing more horsepower than available from dieselgenerator sets presented the best oppor tunity for improvement. Accordingly, a testing and development program was carried out which resulted in the design, installat ion and application of a practical system. This paper describes the development of the system, the equipment used as well as the actual operation. A projection is also made to indicate further improvement in productivity. A comparison is made of truck operating data before and after activation of the trolley assist system in order to determine its economic impact."

Jan 1, 1972

By Paul L. Michael

This report presents a discussion of perforance parameters for electronic or active hearing protectors that will meet the needs of underground coal miners. This information is incorporated into a proposed set of specifications that can be used to judge the suitability of a particular electronic hearing protector for the coal mine application. Acoustic and electrical tests were performed on a developmental model of an electronic hearing protector built by the U. S. Bureau of Mines. This model showed only a slight reduction in speech intelligibility which was traced to poorly matched components and in particular to the transducers. Tests of alternative components showed the Knowles BL-1671 microphone to be suitable for this application because of its performance and extremely small size. The Roan-well H-143/AIC earphone was found to have a good frequency response but has the disadvantage of being rather bulky which causes a slight degradation of a low frequency attenuation of the hearing protector. A satisfactory installation of these components in a hearing protector muff was demonstrated and tested. Results of tests of several methods of controlling the sound level under the hearing protector muff showed that a simple diode clipper circuit can be used with only a negligible loss in speech intelligibility for normal-hearing listeners. A commercially available active hearing protector, the British-built ACOS A-9000/2 was examined. This hearing protector provides sound level limiting through a saturating amplifier. Preliminary tests have shown that the performance characteristics of this commercial unit meet many of the proposed specifications so further testing and evaluation should be performed to determine its suitability for use 1n underground coal mines. The recommended test of intelligibility for electronic hearing protectors and other communication systems as used in a coal mine setting is the Modified Rhyme Test (MRT) developed by House et al. in 1965. The suitability and method of administering this test are discussed.

Jan 1, 1976

By J Crosbie, M Lord, R Bitencourt, P Defferrard

The MMG Century mine, which is the largest zinc/lead mine in Australia, began operating in 1999 and ceased mining from the open pit in July 2015, with processing completed in early 2016. Closure plans were developed from 2006, and detailed planning for closure commenced in early 2011 with the appointment of a dedicated closure planning resource. The site will continue to be managed during the active and passive closure phases to complete rehabilitation commitments and demonstrate that closure completion criteria have been achieved.Completion of the mining/processing phase of the project provides an opportunity to reflect on successes, missed opportunities and lessons learnt with respect to planning and execution of mine closure. This paper highlights examples of success at Century and also identifies key learnings and areas for improvement in progressive closure outcomes. Specific examples examine mine planning and execution involving bulk movement of waste rock and construction of permanent waste encapsulation landforms. The paper also provides recommendations for other sites that are planning for closure.Decisions made during the operational phase of the project life can result in a significant increase in closure liability and reduce the likelihood of achieving lease relinquishment. Likewise, it is of paramount importance to assess the consequences and thoroughly understand the risks associated with changes or deferral of closure plans, progressive rehabilitation targets and closure related key performance indicators.CITATION:Lord, M, Bitencourt, R, Crosbie, J and Defferrard, P, 2016. Closure planning lessons Learnt from the Century mine, in Proceedings International Mine Management Conference, pp 207-216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By Circe Verba, Scott Montross, Jon Yang

This work is a first-order study to assess the suitability of an organic acid lixiviant to extract rare earth elements (REE) from coal preparation fines refuse sourced from a Pennsylvania mine with a total REE of ~ 300 ppm. The extraction of REE using an organic acid, in this case 0.1Mcitric acid and 0.5Mtrisodium citrate solution, is compared against 0.5M(NH4)2SO4, 1MHCl, 1.2MH2SO4, and 0.5Methylenediaminetetraacetic acid (EDTA). Ashing the coal waste material prior to leaching tests with the citrate solution nominally improved REE extraction. Buffered citrate solution recovered 7% of the total REE in the as-received Isabella Fines as compared to 11% in ashed samples, whereas (NH4)2SO4 extracted 5–6%, respectively. EDTA recovered up to 33%of the total REE, most likely due to the higher coordination chelate bond. Mineral acids, however, outperformed the organic acids on ashed material (16–52%REE recovery), suggesting that organic acids may not be a suitable competitive option for REE extraction from these types of feedstocks.

Jun 15, 2021

By S. A. Sass

The design and construction of Solvay Minerals (formerly Tenneco Minerals) Soda Ash Expansion Project, which is the world's most modern natural soda ash facility, is detailed. Along with a discussion of design considerations, the international joint venture ownership and teaming arrangement for design and construction companies is examined.

Jan 1, 1994

By Darold Woodward, Stefan Haydn, Petr Pospisil

Most fatalities in tunnel fires are caused by the spread of toxic smoke. Controlling the spread of smoke is crucial to provide a survivable environment for emergency egress. A properly designed and tuned feedback control loop is required to achieve a target flow that is slow enough to allow pedestrians to escape under different boundary conditions. Feedback control loops are also helpful in optimizing energy consumption under moving traffic conditions. A reliable feedback flow control system requires sophisticated engineering knowhow and experience, careful selection of instruments and controlled variables, and thoughtful implementation from design through field testing and commissioning.

Dec 1, 2022

By E. Ozberk

The copper and nickel smelting industries are important contributors to the technical and economic well-being of Canada while some of the smelters are among the largest sources of sulphur dioxide emissions in Canada. A review of the operations in six smelters - Falconbridge Limited, Falconbridge, Ontario; Hudson Bay Mining and Smelting Co. Limited, Flin Flon, Manitoba; Inco Limited, Copper Cliff, Ontario and Thompson, Manitoba; Noranda Mines Limited, Horne Division, Noranda, Quebec and Gaspe Mines Division, Murdochville, Quebec - have shown that about 80% of the total sulphur input to these smelters was emitted to the atmosphere in 1980. A simultaneous review of the existing and emerging technologies which can directly or indirectly reduce the sulphur dioxide emissions indicated that it is possible to reduce the emissions to below 20% of the sulphur input to these smelters. This can be achieved by varying degrees of modifications to the smelting operations and installing sulphur fixation facilities at significant costs which may increase the metal production costs. This would consequently make the competitiveness of the Canadian copper and nickel producers more difficult in the already tough world metals market.

Jan 1, 1983

By T. P. Chidakwa, T. R. Stacey

This study investigated the corrosion rates of various steel types and coatings used for friction rock stabilisers in a deep-level gold mine under diverse underground environmental conditions. Testing was conducted in situ within ramps, intake airways, and exhaust airways, and through simulated laboratory experiments. Results revealed that environmental variations significantly influence the corrosion performance of different materials and coatings. Duplex coatings, made up of galvanised steel with an organic paint layer, demonstrated the highest corrosion resistance. Zinc-based coatings provided moderate protection, while 3CR12 stainless steel and uncoated S420 carbon steel exhibited comparatively poor resistance under both aqueous and atmospheric conditions.

Mar 4, 2025

By H. C. Carpenter

Lignite tar made by low-temperature Lurgi-Spülgas carbonization of North Dakota lignite was hydrocracked in single-pass, fixed-bed operation at 3,000 pounds per square inch over cobalt molybdate catalyst to produce gasoline, and at the same pressure, over zinc chromite catalyst to crack the high-boiling phenolic compounds to low-boiling phenolics. Hydrocracking the raw tar or the creosote-oil fraction from the tar over cobalt molybdate removed most of the oxygen, sulfur, and nitrogen in the forms of water, hydrogen sulfide, and ammonia, and produced gasoline yields from 31 to 59 volume-percent. The gasoline fractions contained from 0.1 to 7.7 volume-percent tar acids, but tar-base percentages were too low for reliable measurement; removal of these materials with dilute caustic and acid solutions also reduced the sulfur and nitrogen to 0.01 weight-percent or less.

Jan 1, 1963

By P. F. Sands

This U.S. Bureau of Mines report reviews the state of the art in blind pneumatic stowing of backfill in voids in abandoned coal mines. It contains a short history of the development of pneumatic equipment in mining and four recent case histories of blind pneumatic stowing. Limitations of pneumatic stowing in terms of equipment wear, costs, backfill material, and methodology are discussed, and some new procedures and designs are reviewed. A bibliography covering pneumatics in mining is included also. This report provides background for the preparation of a Bureau test program in which the variables affecting the efficiency of pneumatic backfilling will be studied using a full-scale surface test facility.

Jan 1, 1990

By A. U. Miller

Definite progress has been made in accident prevention in Illinois during the past few years; the State Department of Mines and Minerals is receiving excellent cooperation from coal companies and employees, the companies are making greater effort to maintain their mines in good condi- tion, and the employees are eliminating more unsafe practices. As a result, some coal companies have made commendable safety records that prove that coal can be mined with a comparatively low accident rate. However, there is need for further improvement, as the accident rate of the State as a whole is much higher than it should be. During the 55-year period 1882-1936, in- clusive, reports of the State Department of Mines and Minerals show a total of 7,005 (an average of 127.36 per year) men killed in and around the coal mines. Of this number, 6,425 (91.7 percent) were killed underground, 346 (4.9 percent) in the shaft, and 234 (3.3 percent) on the surface. Of the fatalities underground, 3,300 (51.3 percent) were killed by falls of roof, sides, or face coal, 1,167 (18.1 percent) by haulage, 639 (9.9 percent) by handling explosives, 579 (9 percent) by explosions, 151 (2.3 percent) by electricity, and 589 (9.1 percent) by other means. Of the fatalities in the shaft, 171 men (46.5 percent) were killed by falling down the shaft, 14 (41.6 percent) by the cage, and 31 (8.9 percent) otherwise. On the surface, 113 (48.2 percent) of the fatalities were due to railroad cars, 51 (21.7 percent) to machinery, and 70 (29.9 percent) to other causes. The fact that 7,005 lives (an average of 127.36 per year) were lost during 1882-1936 is sufficient evidence that in the past too little interest has been taken in safety by either the management or workers. A realization of this deplorable loss of life should act as an incentive to the industry to make greater effort to prevent accidents in the future. After an accident occurs, the facts pertaining to it become history, and anything that may be done afterward cannot change in any way the damage that has already been done, such as loss of life, personal injury, and destruction of property. The main benefit that can be derived from an acci- dent is that suitable procedure may be adopted and some lesson may be learned to aid in preventing a similar accident in the future. All accidents, par- ticularly serious ones, therefore should be investigated and an effort made

Apr 1, 1938

By John D. Watson

The results of extensive field tests of a new and powerful method of hard rock excavation are presented in this report.* The method, known by the acronym REAM (Rapid Excavation and Mining), employs high velocity, smooth bore cannons to efficiently deliver energy to the rock and has been demonstrated for underground tunneling, drilling, surface benching, scaling, and secondary breakage in hard granitic rock at the Hope Valley Mine test site in California. Solid projectiles made from inexpensive materials such as concrete or steel, and weighing from 8 to 12 pounds, are launched by conventional high speed cannons and impact the rock at velocities of 5000 feet per second--an impact energy of about 4 million foot pounds (Figure 1). The energy applied at peak pressures of nearly 2 million psi over a period of tens of microseconds breaks down the rock by a complex mechanism of crushing, spalling, and initiation and propagation of fractures produced by the interaction of successive impacts and free surfaces. The main objective of the tests during 1973 was a demonstration of controllability of the underground operation of a silenced cannon. To accomplish this objective a 90-mm cannon

Jan 1, 1974

By M Davies, G Theletsane, A H. Gray

Recovery of gold from gold ores has been driven by the available technology and its configuration in the process plant flow sheet.Conventional practice in test work programs has the ore being ground fine (to 106 or 75 microns) to ensure liberation ahead of leaching or flotation. This paper identifies that, in many cases, gold and gold sulfide carriers will liberate and be recovered to a concentrate at much coarser sizes.There is an exponential increase in energy consumption relative to particle size reduction. This impact becomes extreme when comparing crushing a product to 1 mm against grinding to 75?microns.The resultant reduction in energy consumption when liberating and separating at 1 mm or coarser compared to grinding to 75 microns can be in the order of 15 kWh/t or 60 per cent of energy in the comminution circuit.Recovery of free gold and gold sulfide carriers by preconcentration (using continuous gravity devices such as the InLine Pressure Jig), combined with flotation of the fine gold and gold carriers, can result in significant power savings.There are multiple locations within the flow sheet that can be targeted using this process, including recovery in the cyclone underflow of existing plants, preconcentration ahead of the plant or complete greenfield, low-energy process plants designed from first principles based on data from a Gekko developed test work regime.We will describe the process of defining mineralogy in the laboratory and the decision-making process through to actual applications in the field.Several examples will be provided, including a South African Witwatersrand gold ore, several Australian gold ores and others, indicating the benefits of this process and where it has been brought to commercial reality.CITATION:Gray, A H, Davies, M and Theletsane, G, 2014. Coarse liberation and recovery of free gold and gold sulfide carriers for energy reduction in process plants, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 117–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

By Joseph D. Drew

Oregon Resources Corp. (ORC) has developed and permitted a new mining operation that incorporates a process design that will allow the unique paleo-beach placer deposits of southwestern Oregon to be extracted efficiently and economically, creating the only domestically mined source of a unique foundry grade chromite and specialty de-veining sand for precision casting. The operation will also provide an additional domestic source of garnet and zircon. Engineering design has been guided by the variable geology and mineralogy of the paleo-beach placer deposits as well as the need for a dry tailing scheme that resolves a lack of water resources at the placer locations and at the same time eliminates the need for slurry settling ponds, typical of paleo-beach placer operations in North America.

Jan 1, 2010

By G. E. McElroy

Ventilation-pressure surveys are required to determine the rates of pressure losses in various parts of mine-airway systems. These may be determined directly by differential pressure measurements or deduced from absolute pressure measurements, Despite the confusion caused by its inverted nonlinear scale, the altimeter has special application to pressure surveys in mines in which only small differences in elevation are involved, as is true for most of our large bituminous-coal mines in these, the judicious use of information obtained by pressure surveying can result in greatly improved working conditions as regards health and safety and, in many instances, can yield large financial returns. The main purposes of this report are to discuss methods of using altimeters for pressure surveys and to present the particular methods of making surveys and calculating the results of surveys used by the Mine Ventilation Section of the Bureau of Mines.

Jan 1, 1957

By R. J. McClincy

The potential techniques for the direct smelting of copper sulfide concentrates to blister copper were evaluated from the standpoint of commercial application. Many existing smelters are adaptable to direct smelting practice but only with improved control of metallurgical performance. Modified and innovative procedures for slag cleaning and metal refining, prerequisites to direct smelting, are presented and discussed. The ability to smelt directly to blister copper using existing equipment and eliminating the need to convert matte offers ,significant advantages to traditional smelting practice from the viewpoint of cost, 'S02 control, and process simplicity.

Jan 1, 1983

By M. D. Kaizer

PETROBRAS started its Oil Shale process development in 1953, the PETROSIX process which was developed and tailored to Irati Oil Shale formation. Since 1991, the industrial plant called MI (Industrial Module) has been operating, producing more than 20 million barrels of oil. In order to continue the oil shale exploration, a new shale mine is been opening. This article reports the planed measures taking in order to limit the environmental impacts and to return the land as close as possible to the original condition, as well as with the disposition of the process waste and the city garbage. It shows that the remediation process starts during the mining activities and continues after the mine exploration. Another characteristic of the Petrosix process, the pyrolysis of tires will be focused.

Jan 1, 2014

By F. S. Crawford

The wide variation in the medical facilities, type of accident reports and provision for the welfare of employees, in addition to the compensation provided by the various State laws,- was -studi-eci, by the.. wri-ter in the Lake .. Superior_ r.egion . .. - -Several cDmpanies f~rnished. the information which follows. Names have been omitted , ~ut the information should be of .intere·st to companies desirous of improving t_his branch of thej..r accident-prevention work. : . . --Because a summary of the metho.ds used would merel:y: result in _ a.n a.ttempt to set _up an ideal, it was concluded that in preparing this paper a statem.ent .of_ tbe individual methods of -each company wou-l d .b-e .Qf .. the most inte-res.t, . and the.y h~ve . been .. li.steq with .no regard to the size of the company . . ··· -In the - appendix are -a -number of report. forms used by .various _operators for reporting accidents to t he company and .to the State. These are self- explanatory. and many a re mentioned in -the body of circu-1-ar-.

Mar 1, 1932

By X. -G. Chen, J. Qin, K. Liu, D. Racine

"Understanding the thermo-mechanical fatigue (TMF) behavior of materials plays a significant role in the safety design of critical components used in aerospace and automotive industries, such as engine blocks and cylinder heads, which undergo the cyclic change of temperature and stress. However, the cyclic changes of temperature, stress and strain make it difficult using the traditional testing methods to accurately simulate the TMF process. In the present work, the Gleeble® 3800 system was successfully applied to develop a reliable procedure to measure the TMF behavior of aluminum alloys. The modified setup together with the new designed program allows the Gleeble system to precisely simulate the cyclic profiles of temperature and mechanical strain. The novel procedure includes the calibration and verification of the TMF setup to ensure the test validity with Young’s modulus measurement, multi-cycle measurement of the thermal strain and zero stress adjustment followed by online monitoring the TMF cycles. The results of the TMF testing of an AA6061 alloy under cyclic temperatures (60–300°C) and various strain amplitudes (0.2–0.6%) were demonstrated. Its TMF behavior was characterized by the typical hysteresis loops and cyclic stress-strain response.INTRODUCTION The thermo-mechanical fatigue (TMF) behaviour becomes increasing important to evaluate the elevated-temperature properties of materials used as the critical components in automotive and aerospace industries, such as the gas turbines (Hu, Shi & Yang, 2016; Moverare, 2007; Segersäll et al., 2015) and engine blocks (Grieb, Christ & Plege, 2010; Javidani & Larouche, 2014). During the cycles of start-up and shutdown of the engines, these components undergo a complex change of loading. Meanwhile, a dramatic temperature gradient exists on the components due to the cooling system. Therefore, the cyclic changes of load and temperature can give rise to the TMF and may limit the use life of such components (Hu, Shi & Yang, 2016; Javidani & Larouche, 2014; Moverare, 2007). Hence, performing the TMF tests to precisely simulate the cyclic changes of load and temperature to understand the TMF behaviours of materials is playing a significant role in the safety design of these components. For TMF tests, two principal types of cycles are generally employed, including the in-phase (IP) cycle where the load and temperature are at the same phase (i.e. maximum load at highest temperature) and out-of-phase (OP) cycle where the maximum load is applied at minimum temperature (Kliemt, 2012; Miller, 2014). The most significant damage mechanisms in engine components are reported to be OP TMF cycles (Javidani & Larouche, 2014; Kliemt, 2012)."

Jan 1, 2018