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By A. LaPlante, A. Cauchon

This gravity circuit at Les Mines Camchib Inc. consists of two pinched sluices to bleed a feed to one of two 76 cm (30") Knelson concentrator. The Knelson concentrate is upgraded to smeltable grade with a smaller Knelson (18130 cm) and a riffleless table. Their tails are column cyanided and washed prior to recycle to the grinding circuit. This paper details size- by-size circuit performance. The Knelsons recover around 90% of free gold (as determined by Mozley Laboratory Separator), even below 37 pm. The sluices are ineffective, with upgrading ratios around 2, but approaching unity in the fine sizes. Much of the effectiveness of the circuit lies in the high gold circulating loads in the grinding circuit, which partly atone for the poor sluice performance, and the ability of the Knelsons to recover free gold. Secondary upgrading recovers slightly above 99% of the primary concentrate gold, 90% of it in a 65% Au concentrate and the balance in a heavily loaded (10 to 20 oz/st) pregnant solution, generated by intensive column cyanidation.

Jan 1, 1990

By Dale A. Bivens

INTRODUCTION The Waste Isolation Pilot Plant (WIPP) is currently being constructed for the United States Department of Energy in SE New Mexico. The purpose of the project is to store low level transuranic waste in an underground environment which will ensure a safe atmosphere for the life of the stored waste. Ohbayashi was contracted by the DOE to sink two shafts and underground drift development which will be used to conduct a series of long term experiments in order to finalize the suitability of the geology and the environment for the transuranic waste storage. The two shafts sunk at the WIPP site were excavated around a borehole by conventional methods. The excavation around a borehole eliminates some of the established blind bottom sinking techniques, but creates unusual problems which must be pre-planned and scrutinized closely. An analysis of the slashing to the borehole technique will be given. WASTE SHAFT The waste shaft (w/s) is 5.8 meters (19 feet) in diameter and will be used primarily to transport the radioactive waste to the underground storage area. A pre-existing 1.83 meter (6 feet) diam borehole was taken to a depth of 655 meters (2150 feet) to the existing drift; at this level, a 38 meter (125 feet) sump was installed using blind bottom sinking techniques. Geology The primary geology for the w/s excavation is redbeds, anhydrites, dolomite, mudstone and

Jan 1, 1985

By Terry I. Mudder, Michael M. Botz

In general, the cyanidation of silver ores requires higher con­centrations of cyanide in comparison to gold ores to affect simi­lar leaching rates and metal recoveries. The requirement for high cyanide concentrations in a silver ore leaching circuit may translate into higher operating costs, however with operation of an acidification-volatilization-reabsorption (AVR) plant to recover and recycle tailings cyanide, cyanide consumptions can be significantly reduced. At each of the currently operating AVR plants in the world, overall cyanide consumptions have been reduced by approximately one-half by recovering and recycling tailings cyanide. In addition, the AVR plants have reduced tail­ings cyanide concentrations to less than 20 to 30 mg/L WAD cyanide and reduced potential adverse impacts to wildlife in the tailings impoundments. This paper presents an analysis of the application of A YR to a silver ore leaching operation which has a CCD/Merrill-Crowe circuit included in the metallurgical plant.

Jan 1, 1998

By R. P. Upadhyay

The Deserado Mine, located in northwest Colorado, is an underground coal mine designed to produce 1.225 million tons (1.35 million short tons) of clean coal per year for the Bonanza Plant located in northeastern Utah. Coal is transported to the power plant via a 61 kilometer (38 mile) captive railroad. Most of the surface facilities and the stationary underground equipment is controlled and continuously monitored by the computers located at the surface control room. In addition to system control, the computer also continuously monitors vital environmental conditions using sensors located at various critical locations underground. The system's advantages are increased mine productivity and safety.

Jan 1, 1988

By M. Kaya

The main purpose of this study was to design a modular/mobile coal preparation plant with a capacity of 300 t/h for Seyitömer B3 vein (almost 70% of the whole SLI deposit). Firstly, coal washing properties and washability curves were determined by sink and float tests. Then, equipment sizing, selection, flow sheet development, economic evaluation, investment and operating costs were determined for coarse (-150+18mm), fine (-18+0.5mm) and slime (-0.5+0.1mm) coals. Economic evaluation of the proposed flow sheet showed the feasibility and profitability of the investment.

Jan 1, 2006

By Jon Y. Kaneshiro, Gregory E. Korbin, Stephen J. Navin, Larry J. Stout

Sewage presently being discharged into the Tijuana River Valley pollutes the valley as well as the beaches in the South Bay of San Diego, making the beaches unusable nearly year round. The SBTO will convey flows down a 8.5 m (28 ft.) by 58 m (190 ft.) deep drop shaft, through a 3.35 m (11 ft.) by 5.8 km (3.6 mile) long tunnel, and up a 46 m by 2.7 m (150 ft. by 9 ft.) riser shaft connecting to a 1.5 km (0.95 mile) of seafloor pipeline and 1.2 km (0.76 mile) of diffusers on the ocean floor. The drop shaft will be sunk through 38 m (125 ft.) of saturated sands and gravels and 20 m (65 ft.) into the dense fine sands of the San Diego Formation. The tunnel liner has been designed as a five piece, single pass, gasketed, bolted, reinforced concrete liner designed to withstand an external head of 76 m (250 ft.) of water and internal operating head of up to 27 m (89 ft.) and to accommodate movement at the numerous fault crossings. The tunnel is contemplated to be driven with a state-of-the-art Earth Pressure Balance Machine (EPBM) or slurry shield machine through a wide range of conditions from clay to gravel with boulders.

Jan 1, 1995

The Carlin Trend is North America's premier gold producing district. It is located in northeastern Nevada's Elko and Eureka Counties along a northwest trending belt about 65 km (40 miles) long and 8 km (5 miles) wide (Thorstad, 1989; Jones, 1989). This trend is the worldwide reference site for epithermal, sedimentary rock-hosted microscopic gold deposits. At least 19 deposits have been discovered to date, varying in size from 933 kg to 1.08 kt (30,000 to 35 million contained oz) of gold (Fig. 1). Newmont Gold Co. and its parent, Newmont Mining Corp., jointly constitute the largest mineral right holders in the district. They own or control more than 1000 km'- (386 sq miles) in and around the Carlin Trend and own all or part of 16 out of the 19 mines and prospects identified to date. Since the initiation of Newmont's exploration activities in the Carlin Trend in 1961, 2.24 kt (72 million oz) of cumulative gold resources have been identified. Cumulative production from all mines since the start-up of Newmont's Carlin mine in 1965 to the end of 1989 was about 202 t (6.5 million oz) (Jones, 1989). The incentive of sustained high gold prices and innovation in processing technology resulted in a significant acceleration of gold output over the last few years. Newmont Gold alone produced more than 43.5 t (1.4 million oz) in 1989. That is equal to 22% of the cumulative 1965 to 1988 output, and an almost 200% increase over its 1986 output.

Jan 1, 1991

By Song Xiaotian

In this paper the enviroment in which Tong Kuang Yu mine, China is developed is described. Geological and geomechanical environments which pose difficulties in the design and optimization of Block Caving are discussed. According to mine conditions, caving process simulation was carried out using Displacement Discontinuty Method and relationships between stress distribution .and undercut parameters were established in accordance with different undercut sequence. Based on simulation the influences of caving parameters on caving probability, drift instability and ore-draw control were analysed in order to optimize Block Caving Mining. On the basis of simulation and mathematical programming, the optimal sequence is proposed essential to satisfy the safety, production and other restrictions.

Jan 1, 1989

By Hugh E. Cronin, John Ramage

The recommendations resulting from a Dispute Review Board (DRB) hearing of a contract dispute are being challenged more and more frequently. This paper explores possible causes based on the authors’ experiences. Challenges facing the DRB process include: The DRB process is starting to lose some of the informality and flexibility. Both owners and contractors appear to be putting too much weight on a board recommendation on a dispute. DRB’s do not make “decisions,” they provide recommendations for dispute resolution to both parties. The DRB process is not just for contractors to present an unresolved issue to a board hearing. Owners can also initiate a request for a hearing on a disputed issue. For the DRB process to remain a viable element of the successful construction project, confidence must continue to be maintained in a process that is intended to work on behalf of both parties to the construction contract.

Jan 1, 2003

The last twenty years of development in Process Mineralogy are reviewed. Since the milestone review by Henley in 1983, which projected the concept and suggested closer working relations between mineral processing and mineral science, the second generation (1983-2003) has made significant progress. Examples are to be found in improved sampling and high-confidence flotation testing, and in automated quantitative mineral measurement. The recent addition of end-member studies has provided a clearer view of the overall ore mixture milled from its constituent geological components. In all, better predictive abilities have resulted from these improvements to Process Mineralogy. These improvements have led to more significant business impacts in mineral resource characterization, and in optimization of existing concentrator operations.

Jan 1, 2004

By Yashar Pourrahimian, Magreth S. Dotto

Fragmentation by blasting is a critical process in hard rock mining. The blasting process and outcomes are highly influenced by rock mass properties and their response to higher stresses and loading rates. Each rock mass is unique, but some features affect the blast energy similarly, leading to similar outcomes. Having analyzed these features and their influence on blast results, they can be incorporated into the blast design to achieve better outcomes. This paper presents a numerical model validated by a case study from the actual mine blasts that studied the effect of rock mass properties on explosive energy production, attenuations, and overall blast outcomes. The results show that when the model parameters are calibrated based on real data, they can be used to simulate the fragmentation process and therefore be used to aid blast design.

Jun 25, 2023

By Vi-Duong Dang

Lithium requirements in the next few decades for batteries and controlled thermonuclear fusion reactors (CTR) may exceed the availability of the current mineral and brine reserves. It is thus prudent to search for new reserves and resources to satisfy these and future lithium applications. The lithium content of the waters from the Smackover oil field. located in the Gulf Coast region of the United States, ranges from 100 to 500 mp/l and could represent a substantial new reserve. Experimental evidence described in the literature indicates that a specific chelating agent dipivaloylmethane (DPM), of the diketone type, has a specific selectivity toward lithium in the presence of other metal ions in aqueous solutions. Based in part on this unique property of dipivaloylmethane, a conceptual design of a full-size plant to extract lithium from the Smackover brine is presented in this paper. This study includes alternate flow-sheet development, design information on the major units of the process, energy requirements, and an economic analysis of a facility capable of producing 106 kg of lithium per year. The economics of three different process concepts depend primarily on the amount of water needing to be evaporated from the initial oil-field feed waters in concentrating the brine. The results, as a function of production rates, are indicated only in a general manner.

Jan 1, 1978

By Roger J. Hornberger, Paul F. Ziemkiewicz, Dirk J. A. vanZyl, Gene E. Krueger, Harry H. Posey, Kim A. Lapakko, Charles H. Buckmam

The Acid Drainage Technology Initiative (ADTI) was initiated in 1995 by federal agencies, the National Mining Association and the Interstate Mining Compact Commission to identify, evaluate and develop cost- effective and practical acid drainage technologies. In 1999 ADTI was expanded through the addition of the metal mining sector group, which began organization efforts in 1998. ADTI addresses drainage quality issues involving metal mining and related metallurgical operations and acid drainage from coal mines, for abandoned, active, and future mines. ADTI is a technology development program. It is not a regulatory or policy development program. The guiding principle of ADTI is to build a consensus among industry, federal and state regulatory agencies. ADTI is focusing these efforts on technology development and technology transfer in the areas of mine drainage sampling/monitoring, prediction, avoidance/remediation and modeling.

Jan 1, 2000

By Stanislaw Wasilewski, Zdzislaw Krzystanek

Ventilation process in deep mines features relatively low efficiency. Commonly used passive control by means of regulators and flow throttling leads to remarkable energy losses that could be lower if effective monitoring and remote control of main fan operating point were implemented. In the paper, some results of investigation carried out in Polish coal mines to evaluate real energy losses in ventilation process are described. Different methods for main fans performance monitoring and control are considered and compared especially those using fan drive speed control to minimize power consumption. On the other hand some criteria for power evaluation are analysed and algorithms for optimum location of controllers in ventilation network are considered. The results of investigation are being implemented in the first system for monitoring and control of main fan operating point in Miechowice colliery.

Jan 1, 1995

By Edoardo Misano, Magali Schivre, Martino Semeraro, Alain Bochon

"INTRODUCTIONThe Laboratoire Souterrain de Modane (LSM) is an underground research laboratory located in the Western Alps on the French – Italian border. It is located in the middle of the 13km long Fréjus highway tunnel that links Modane (France) to Bardonecchia (Italy) in correspondence of the highest overburden of 1800m. The LSM current activity is mainly based on the investigations about the dark matter and requires very sensitive instrumentation which shall be protected from cosmic rays. To comply with the new legislation about safety in tunnels, the highway tunnels owners agreed in 2007 the construction of a parallel safety tunnel, at an average distance of 50m from the existing tunnel and the laboratory owner CNRS (Centre National de recherche scientifique) also decided to extend the existing laboratory with the construction of a new 17000 m3 cavern allowing the installation of wider and more powerful instruments that could increase chances of success of research. Preliminary studies stated that, considering both geological and functional issues, the most appropriate location for the new laboratory shall be in between the two tunnels and parallel to the existing laboratory (see Figure 1).Hence, the CNRS asked Systra, already in charge of the works supervision of the safety tunnel, to realize the design of the new cavern. The laboratory extension includes the construction of a 40 m long cavern with 300 m² cross section and two smaller tunnels connecting the safety tunnel and the existing laboratory to the new cavern. The minimum distance between the front face of the new LSM and the highway tunnel is about 25 m.The French and the Italian authorities, responsible of the exploitation of the Fréjus highway tunnel, asked the CNRS to develop an accurate study indicating that the construction of the laboratory extension would not have any negative impact on the existing structures of the highway tunnel. The main results of the developed study by Systra are summarized hereafter. The construction works should begin prior to the end of the construction works of the Fréjus safety tunnel in 2018."

Jan 1, 2016

By Robert L. Bates

United States production of the industrial minerals, ahead of that of the metals since 1946, has shown a steady and rapid growth. By 1963, their value was more than twice that of the metals. Yet papers on the metallic ores continue to dominate the meetings of the Society of Economic Geologists and constitute nearly nine-tenths of the lead papers in Economic Geology. Most of the geological communication that does take place concerning the industrial minerals deals with high-value special-purpose minerals, which are comparable to the metallic ores in geologic complexity. The large-bulk rock products, which are growing fastest in production value, are characterized by relatively simple geology and by thousands of small producing firms, many of which do little or no geological work. The need for geological advice by this very large segment of the industry is bound to increase. In the meantime, a plea is made for more geological communication among those concerned with the industrial minerals of all varieties.

Jan 1, 1966

By Jesus M. Rohena

Concrete pipes and small boxes have been installed by the jacking method. This paper will describe a recent project were large concrete boxes were installed by the jacking method. This project is in the city of Boston, MA. By now everyone in the USA knows something about this project. The project official name is The Central Artery/Tunnel Project (CA/T). This is the biggest public work project in the USA right now, with an estimated construction cost of 14 billions. The main objective of the CA/T project is to replace an existing artery built in the 1950s to increase capacity and safety. One section of the new artery will cross under several railroad tracks near the South Station. To construct the section of the new artery under these tracks, big concrete boxes were installed by the jacking method. The jacking method can be used to install pipes, small concrete boxes, and the CA/T project has demonstrated that big concrete road tunnel boxes can be installed by jacking.

Jan 1, 2003

By G. M. Bernard

This paper provides an overview of the various methods and techniques for transporting and stacking ore on heap leach pads. Towards this end, brief discussions of the various methods and techniques important to this process are presented.

Jan 1, 1993

By Laurindo De Salles Leal Filho

Microflotation tests with sodium oleate, in alkaline pH, were performed with apatite and some silicates (phlogopite, quartz, and chlorite) that commonly occur in Brazilian phosphate ores. Further flotation tests were carried out with selected ores containing the same silicates as important gangue minerals. The results showed that apatite recovery is highly affected by competition with silicate minerals, probably activated by calcium ions dissolved in flotation pulp. Inorganic chemical species (sodium tripolyphosphate, sodium carbonate/ bicarbonate, and carbon dioxide) that could act as water softeners were used as modifier agents. They proved to be capable of improving flotation recovery and selectivity.

Jan 1, 1999

By C. K. Blair, V. J. Hucka, E. P. Kimball

In central Utah, a coal mining operation is taking place under an 0.5-m (20-in.) pressurized natural gas pipeline. The room-and-pillar method with pillar extraction is being used to extract the coal from the seams. The pillars beneath the pipeline will not be extracted; however, there is a possibility that some subsidence may occur due to pillar failure. To assess possible damages on the pipeline, an attempt has been made to predict subsidence in the area where pillars may collapse. The resultant values of subsidence strain and slope have been used to determine the magnitude of strain, stress, and shear induced in the pipeline. Also, a network of survey points has been installed along the pipeline to detect ground move¬ment that would indicate excessive subsidence.

Jan 1, 1987