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By J Langhans, Y Choi, Q Wang, J Y. Baron, P Kondos

Barrick has successfully developed the thiosulfate leaching process to treat sulfidic high preg-robbing ores. The process was developed through rigorous bench test programs and proved in pilot campaigns and demo plant operations. The process uses calcium thiosulfate as a leaching reagent, resin for gold recovery with sulfite/trithionate elution and reverse osmosis as a mean of reagent recovery. The thiosulfate leaching plant is under construction as a brownfield project and the start-up is planned in 2014 at Goldstrike, Nevada, USA, one of BarrickÆs operations.CITATION:Choi, Y, Baron, J Y, Wang, Q, Langhans, J and Kondos, P, 2013. Thiosulfate processing - from lab curiosity to commercial application, in Proceedings World Gold 2013 , pp 45-50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By R. T. Johansen

A gradual decrease in injection rates commonly occurs as a water-flooding project becomes older. This decrease can be attributed to changes in reservoir conditions, such as swelling of clay minerals, fillup, or gradual plugging of the sand face. However, a rapid decrease in the rate of injection indicates abnormal behavior and is cause for alarm. Extreme plugging conditions can completely stop injections into a formation. Such behavior in wells was the main concern of the tests described in this report. An accepted method of alleviating this condition is by backflowing input wells - closing the supply lines to the wells and allowing the reservoir pressure to force water back into the wellbore and to the surface. If backflowing is not successful, a string of smaller diameter pipe sometimes is run inside the casing, and the sand face is flushed with a waterspray. More drastic treatment is to inject acid into the wellbore to dissolve extraneous matter, or even part of the reservoir material, in an attempt to restore the permeability of the sand immediately around the wellbore. Any of these procedures can he coordinated with bailing and swabbing of the well for cleanout purposes.

Jan 1, 1957

By B. Tolwinski

Long-Term Open Pit Scheduler or L-TOPS is a new software package for evaluating, planning, and design of open pit mines. L-TOPS transforms geological, economic, and technical information about a mineral deposit into a detailed mining schedule that maximizes economic efficiency without neglecting the practical requirements of mining operations. L-TOPS has been customized for integration with Placer Dome Inc.'s existing in-house resource/reserve optimization software to function as a primary tool for property acquisition studies and for the designing of mines for feasibility studies. This pa-per presents an overview of L-TOPS and reports on its application to Placer Pacific's (Placer Dome's Australian affiliate) Mt. Rawdon project.

Jan 1, 1996

By Y. Jiao, V. S. Thompson, D. W. Reed, Y. Fujita, J. E. Aston

Rare earth elements (REE) are vital components in modern electronics and green technology products. Supply is tight and global demand is expected to increase, leading to high risk for the economic and national security of countries largely dependent upon foreign supplies. Recycling of REE from consumer and industrial waste materials is a possible way to help meet demand. We have shown previously that biohydrometallurgy can play an economically and environmentally sustainable role in REE recycling, particularly if agriculture or food wastes are used to produce organic acid bioleaching agents. A challenge for organic acid-based bioleaching is the incomplete conversion of the carbon substrate to an optimal organic acid biolixiviant with high REE extraction capability from a variety of REE-containing feedstocks (e.g., mining wastes, magnets from end of life products, spent batteries, etc.). To help meet this challenge a metabolic model was developed for Gluconobacter oxydans to identify options for improving sugar conversion to organic acids. Model predictions were consistent with laboratory data for the microbial consumption of glucose and production of gluconic acid, and suggested that providing growth conditions with relatively high C:N molar ratios could result in lower pH biolixiviant production and thus improve bioleaching. Keywords: Gluconobacter oxydans, bioleaching, metabolic modelling, rare earth elements summaries 2019: U.S. Geological Survey, 200 p., https://doi.org/10.3133/70202434.

Jan 1, 2020

By Ning Wang, Tengfei Guo, Wanyan Li, Hanjie Wen, Hannian Gu, Zehai Li

Bauxite residue (red mud) is an alkaline waste derived from the industrial process for extraction of alumina from bauxite ore. Some bauxite residues contain considerable concentrations of critical metals, for example, rare earth elements. Lithium in red mud was also reported as a potential resource. In the current study, a Li-rich red mud was leached using acetic acid to investigate the leaching behavior of lithium followed by neutralizing with hydrochloric or oxalic acid. By neutralizing red mud using diluted hydrochloric acid (0.01 mol/L), 58.04–60.27% of lithium was leached using 25% acetic acid at 95 °C for 60 min. In the meantime, more than 95% of sodium and 85% of calcium were also dissolved in the leachate solution. While oxalic acid (0.5 mol/L) was used to neutralize red mud prior to acetic acid leaching, lithium performed lower leaching efficiencies (42.41–46.88%) in comparison of using of hydrochloric acid–neutralized red mud. Nevertheless, these leaching efficiencies of lithium were close to that of calcium and much higher than those of sodium under the condition. In this study, 25% (v/v) of acetic acid, at 85 °C for 60 min, was demonstrated as optimum conditions for lithium extraction from oxalic acid–neutralized red mud using acetic acid. The results would be useful and of interest for lithium recovery and purification from red mud.

ON THIS page is a photograph of a machine that has played a key role in the recent history of Kennecott's Ray mine, situated in the Mineral Creek District, Pinal County, Arizona. It is a huge, rugged, Diesel-powered, rubber-tired truck, having a capacity for carrying fifty tons of ore. It has, to a substantial degree, revolutionized the business of moving broken rock by cutting down both maintenance and operating costs. From 1911 until the end of 1954 Ray had produced 79,000,- 000 tons of ore by underground block-caving. However, in 1947 [ ]

Jan 1, 1957

By Phillip E. Butler

The Pennsylvania Dept. of Transportation is actively engaged in the utilization of coal mine refuse in the construction of highway embankments. Long-held objections for utilization are invalidated by research, laboratory data, and construction performance. Laboratory, engineering, construction, and environmental impact analyses are presented from the construction of the Cross Valley Expressway embankment at Forty Fort, Luzerne County, Pa. Comparisons of laboratory data and construction measurements are given. The refuse embankment is the first of its size in Pennsylvania, and possibly the U. S., covering 1.5 million cu yd.

Jan 1, 1977

By A. A. Nourbakhsha

During the last few years, low cement castable refractories found more application in industry, because of good low and high temperature mechanical properties.In the case of alumina based castables ,usually fume silica or reactive alumina are used as superfines in the matrix to form mullite at high temperature which depends to source of alumina . Mullite network formation improves the hot mechanical properties and thermal shock resistance of bodies. The mullitisation of andalusite (so called primary mullite) also produces a certain amount of rich silica glass, part of it being expelled out of the grain. This phenomenon restrict the application of andalusite low cement castable in pig iron ladle. In this research, firstly 8 pig iron ladles from ESC(esfahan Steel company) with different conditions selected and monitored during usage to determine of main factors affecting on corrosion of refractories. Results showed that tap to tap time and undischarged pig iron are the main ones.Therefore monolithic refractories such as castables which increase thermal shock resistance could be substituted. Regarding to ternary phase diagram of Al2O3-SiO2-CaO ,fumed silica was selected as fine particle.After optimization of particle size distribution by using of modified andreasen equation and rehological properties ,different mixture were composed with andalusite ,fume silica, reactive alumina,secar 71 ,SiC and kyanite.All aggregates system components were mixed dry for 1 min in hobart mixer .After water addition wet mixing was continued until getting flowing about 4 min.The ready mixes were poured in the moulds of of 25mm X 25mm X 140mm with vibrations .After demoulding the samples were cured for 24 hrs and dried at 110OC/18hrsand then fired at 1100-1500OC. Physical ,mechanical ,phase analysis(XRD) and microstructure studies (SEM)were carried out according to ASTM standards. Results showed that by addition of kyanite ,more mullite phase formed through the matrix but,because of expansion occured during this phase transformoration, some cracks formed and mechanical properties decreased.By SiC addition the silica film on the surface of SiC lead to improvement of mechanical properties at high temperature

Oct 1, 2011

By Hermann A. Derbuch

Twin Mining made a conscious decision when it changed from gold mine explorer and developer to become a diamond explorer in Canada?s Arctic. It was a decision of survival in an environment that saw junior gold companies either disappear or turn into dot com companies. Twin Mining learned fast and staked within weeks of that decision the first 50 sq. km of claims on, what became, its TORNGAT property at 59½° latitude on the east coast of the Ungava Bay in northern Quebec. This land position, 724 diamonds later (including 322 macro diamonds of gem quality, white and transparent) grew to 507 sq. km today. The 74° latitude called when Twin Mining exercised the option to acquire 3 claims owned by Helix Resources Inc. which revealed exceptional diamond potential. A gem quality 5.4 mm (0.768 carat white and transparent) diamond and the discovery of 16 pipes on 15.2 ha convinced Twin Mining?s board to sanction the deal. Both properties have outstanding features. Kimberlite Dykes and Pipes are in outcrop. The property locations have deep-sea access near existing infrastructure. Their locations are in an environment that is stable and development friendly and has a positive track record with successfully operating mines near-by.

May 1, 2001

By H. Bilgin, Sedat Esen

In this paper, the ground vibrations induced by blasting for stripping work at Sekkoy Open Cast Coal Mine belonging to TKI Yenikoy Lignite Mine (YLI) are investigated and the procedures for monitoring and control of ground vibrations are presented. Ground vibration measurements are conducted in the direction of Turkish Electricity Authorities’ Yenikoy Establishment and social facilities because of the complaints and annoyance arising from this site. Forty ground vibration records are taken in this direction and the vibrations are measured in transverse, vertical, longitudinal components together with peak vector sum. After then the scaled distance relationship is determined at 95% confidence value. Further, Fast Fourier Transform analyses are carried out to determine dominant frequencies for both ground and the structures and amplification factors. When the records taken at four different structures together with the ground are evaluated, it is observed that one of the apartment buildings is amplified the amplitude of longitudinal component 4.3 times. The maximum allowable amount of explosive that can be fired safely at this mine is calculated and recommended on. In the determination of safe amount, 95% confidence line, USBM RI8507 and OSMRE criteria, the dominant frequencies of both ground and the structure, amplification factor and the human response are taken into account.

Jan 1, 2001

By Shinya Hodoshima

A catalysis pair of tetralin dehydrogenation / naphthalene hydrogenation has been proposed in the present paper as a liquid organic hydride for operating stationary fuel cells. Catalytic naphthalene hydrogenation, having been commercialized since the 1940s, proceeds to generate decalin via tetralin as an intermediate. The storage capacities of tetralin (3.0 wt%, 28.2 kg-H2 / m3) are lower than decalin (7.3 wt%, 64.8 kg-H2 / m3) but both tetralin dehydrogenation and naphthalene hydrogenation are much faster than the decalin / naphthalene pair. Moreover, existing infrastructures such as gas stations, chemical tankers and tank lorries are available for storage, transportation and supply of hydrogen. With respect to the stationary fuel cells with large space for hydrogen storage, tetralin as a hydrogen carrier is superior to decalin in terms of fast hydrogen supply or power density. Rapid hydrogen supply from tetralin under mild conditions was only accomplished with the carbon-supported metal catalysts in the ?superheated liquid-film states? under reactive distillation conditions. In contrast to the ordinary suspended states, the catalyst layers superheated in the liquid-film state gave high catalytic performances at around 250OC. As a consequence, both serious coke formation over the catalyst surface and excessive consumption of exergy were prevented simultaneously.

Jan 1, 2006

By W. L. Freyberger

In a study of the kinetics of flotation of coal, employing a single-cell continuous flotation system, Jowett and Safvi1 pointed out that it was experimentally impossible to float all of the coal which could be floated in a batch tests. On the other hand, deBruyn and Modi, in a discussion of their paper, suggested that under certain conditions the recovery of floatable material from a similar one-cell continuous system would have been 100%.2 Both of these pairs of authors make the assumption that a state of perfect mixing exist in the flotation cell. This assumption, usually made by investigators studying flotation kinetics in a continuous system, has been confirmed experimentally on several occasions. The work is summarized by Arbiter and Harris.3 It is the purpose of this note to demonstrate that, for conditions of perfect mixing, one of two conditions exist: 1) the recovery of floatable material is 100%, and the flotation is infinitely fast, or 2) the recovery of floatable material must be less than 100%. This theorem can be proved simply in the following manner: 1) If recovery, R, of the floatable material is 100%, the concentration in the tailing must be zero. This follows from the definition of recovery as

Jan 1, 1964

By W. D. Bensema, J. W. Adams

A portable, multichannel battery-operated mine-permissible measurement system was developed to measure the rms magnetic-field noise spectrum in the frequency range from 100 Hz to 375 kHz. During each measurement, the entire spectrum is measured simultaneously through the use of time-domain recordings which are later analyzed by Fast Fourier Transform processing. Dynamic ranges of 60 dB in a 125 Hz bandwidth are obtained for spectra covering the range from 100 Hz to 100 kHz. The method also allows a three-dimensional display of the way spectrum occupancy changes with time. Calibration and correction procedures allow absolute field strength measurement with an uncertainty of not more than 3 dB. We feel that further analysis of the system errors will allow this uncertainty to be reduced to less than 1 dB. Ambient magnetic field noise spectra covering frequencies from 100 Hz to 100 kHz are given for several underground coal mine locations. Examples are also given of magnetic field noise on the surface above the mine, noise in the mine face area, noise radiated by specific equipment, the voltage spectrum found on a 600 V dc trolley wire, and noise picked up simultaneously on loops and on roof support bolts.

Jan 1, 1973

By R Barrette, V Lawson

Over the last year at Clarabelle Mill, three circuit reconfigurations were implemented. One circuit reconfiguration, æA CleaningÆ, was initiated due to a furnace failure at the smelter complex, and two of the circuit reconfigurations, æincreased copper (Cu) separationÆ and the æInterim IsaMillÖ circuitÆ, were seen as opportunities to increase cash flow through the mill. A Cleaning and the Interim IsaMillÖ circuit took advantage of engineering design already completed for a major capital project. The engineering for each was modified, as needed, and construction of the required portions of the capital project was fast tracked. The increased Cu separation circuit change used existing test and plant equipment to increase the plant Cu concentrate production. Implementation of the projects required teams that included operations, maintenance, technical support, project management and capital project resources. This paper discusses the business reasons driving the changes and the forethought or synergies with other work, which made them a success, and what was learned through each project. CITATION:Taylor, A, Lawson, V and Barrette, R, 2012. Responding to the challenge - Necessity driving circuit change, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 247-254 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

By Francis Cameron

Mining is both exciting and rewarding-although at times somewhat frustrating-and we all can have real pride in our industry, in its people, and in its accomplishments. It is, however, with concern that I have noted a deterioration in this Country in what might be called mining's stature and in the growth of a belief in many quarters that our mineral reserves are rapidly approaching exhaustion. In other words, there is a popular image that we are fast becoming a "have not" nation in many respects and that the domestic mining industry can no longer be considered, in the vernacular of Wall Street, to offer much in the way of "growth potential." I do not subscribe to this hypothesis, nor do I believe that the record of the mining industry bears this out. However, let me add that we can, in time, talk ourselves into this frame of mind and we can hasten the day when this very well might come about by unnecessary and unwise legislation or regulation. My remarks today are basically designed to give my reasons for refuting this negative philosophy and to review our record. With your help, I know we can improve our image, and the public's recognition of our industry's peculiar problems.

Jan 4, 1968

MIXED emotions were produced by the announcement that the buildup of weapons will be stretched out till mid-1954 instead of the previous 1953 deadline. Reason: government assistance programs will be tougher to get but there will be easement in materials allocations. Earlier in February, DPA had announced that tightening up on regulations governing rapid tax -amortization would become effective March 1. In the future, DPA will have to certify amortization contracts for all construction and permanent installations costing more than $100,000. This action was necessary according to DPA's James F. King, so that new industrial expansions already approved could be assessed in the light of the changing critical mineral picture. When DMPA inherited the backlog of government assistance, requests from DMA, it moved in fast. The results of DMPA's work is described in the article on p. 351 by James K. Richardson; The speed with which these requests were approved and the lengthening of the military program have made a reappraisal of the critical mineral list necessary. It looks as though the consumer industries will be getting more metal soon and, led by steel, there is an industry push toward the abandonment of CMP. Relaxing of materials controls appears imminent but discontinuing CMP is in the "let's talk this thing over" stage.

Jan 1, 1952

By Gene Long

10.4-1. Load Design and Construction. Surface mine haulage roads are used for transporting raw products to the mine site, preparation plant, or loading facilities, and to provide personnel and equipment an access to the pits and mine area. All of the aspects of highway engineering, including minimum slope inclines, properly banked curves, and adequate drainage, must be followed to facilitate construction of safe and efficient haulage roads for fast and economical transportation of the mined product to its destination. By maintaining good haulage roads, both truck and equipment maintenance will be kept to a minimum, resulting in reduced mining costs and subsequently higher profits. [ ] There are several basic considerations in haulage road planning. Most important, one must follow all safety procedures in both design and construction of the roadway. A maximum effort should be made to follow current mining plans when laying out and planning haulage roads (aerial photographs can be extremely useful in planning and routing of roadways). Grades, road widths, and curves must be maintained within limits of present and/or planned haulage equipment specifications, since all these factors can limit speed, and hence production (Table 10.4-1). Grades in most mining operations are adverse (against the loaded haul), which increases haul cost per mile. Operators must balance these increased

Jan 1, 1968

By S. K. Pan, M. P. Srivastava, N. Prasad

"Dalli mines of Bhilai Steel Plant, India is fully mechanized iron ore mine having wet processing system. It has a capacity to treat 5 Mt of ROM. In processing circuit of Dalli mines, scrubbing, wet screening and classification operation is being carried out. Average slime generation for the last five years is about 14% of ROM. As the mining has reached to the lower benches, fines generation is more. As a result, very fine and heavy particles, which settle fast, are being discarded with the slime to tailing pond. These heavy and faster settling particles were causing jamming in the thickeners.Laboratory investigations were carried out at Research and Development Centre for Iron and Steel (RDCIS) to suggest a suitable scheme to recover high quality fines so that the availability of thickener can improve. The slime samples were first treated in a floatex density separator. The concentrate obtained from the floatex density separator was treated in hydrocyclone. Laboratory investigations indicated that the slime with 49% Fe, 12.7% silica and 10.7% alumina can be upgraded to 62.1% Fe, 3.3% silica and 2% alumina with 36% material recovery. Based on the laboratory studies ,a system was installed at Dalli minesThe general arrangement of the system is shown in Fig. below."

Jan 1, 2003

By J. Scott McDougall, J. Herman P. Eng. Vanderlaag

An underground mine fire can seriously threaten the lives of all personnel in the mine. This fact makes fire emergency planning a high priority in the mining industry. The optimum warning alarm must be fast and able to reach all miners, regardless of their location or work activity. Current means of fire warning are varied, and include such methods as stench, telephones, and word-of-mouth (messengers). Unfortunately, none of these methods are entirely satisfactory. A novel fire warning alarm which enables instantaneous warning of all underground personnel, the Canary Nine Messenger System, has been developed by VLF Magnetic Systems Inc. in conjunction with Noranda Technology Centre and the U.S. Department of the Interior - Bureau of Nines. The warning is sent by an electromagnetic signal which penetrates through mine rock to receivers housed in the battery packs which also power each miner's cap lamp. A loud buzzer in the integrated battery/receiver unit and the flashing of the cap lamp alerts miners to incoming messages. Testing of prototype equipment has demonstrated that the transmitted signal is capable of penetrating through over a mile of mine rock and activating the receiver. This report describes the theoretical basis for through-the-rock ultra-low frequency electromagnetic transmission, and the design of recently available transmitter and receivers.

Jan 1, 1995

By Bruce Cavender

Managers are frequently faced with the decision to perform a task or manufacture an object in-house or to hire an outside vendor to perform the function. Outsourcing decisions are usually driven by economics: work is outsourced if it can be completed at a lower cost or in a shorter time than it can in-house. A technique termed incremental analysis can be used to make this decision. Incremental analysis examines the financial impact of outsourcing decisions as a function of the firm's fixed and variable operating costs. To use this tool, individual components of production cost are identified as being either constant or varying with levels of production activity. The assignment of cost type can be made in several ways: though analysis of historical operating data, understanding of individual expense types, and so forth. Changes in fixed and variable costs resulting from each potential course of action are explicitly identified to project the financial outcome of each alternative. The alternative having the greatest positive impact on profit is selected for implementation. By using the fixed- and variable-cost framework, the analysis is conceptually straightforward and substantially simplified. Production managers can therefore use incremental analysis as a tool for fast economically beneficial decisions on a real-time basis.

Jan 1, 1999