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By George R. Huebner

The present mine at White Pine has been extracting low grade copper ore by mechanized room-and-pillar methods for approximately eleven years. Increasing depth of mining is decreasing the extraction ratio. It is desirable to mine a higher grade product by extracting values only and increase recovery of the available natural resource. These factors led to the consideration of a caving method such as longwalling. GEOLOGY The White Pine orebody consists of two mineralized shale horizons separated by a relatively barren zone of shale and sandstone. These gently dipping sediments lie at the base of the Nonesuch shale formation and are of late Precambrian age.

Jan 12, 1964

By C. R. Tatman

Failure to achieve the planned production rate at new mines and mine expansions has a major adverse impact on a project's economics. A study of 60 steeply dipping tabular deposit-type underground mines showed that 35% of the mines did not achieve their production goals. An empirical formula based on the geometry of the deposit and expressed as a rate factor is applicable to select a production rate for this type of deposit. The formula is: Annual production rate = Rate factor x Rate multiplier. The appropriate rate multiplier for each category of deposit thickness and the associated risk can be used to select an appropriate production rate.

Jan 1, 2002

By N. S. Harding, M. C. Mai, A. G. Fonseca

Many coal characteristics affect combustion performance. Mill wear, boiler efficiency and derate, slagging, fouling, and ash collection and removal are only a few of the impacts of coal quality on boiler performance. The ability to assess fuel characteristic impacts on busbar costs is essential, although difficult to obtain. The relationships between coal characteristics and ignitability, operability, slagging, and fouling were investigated. The examination of combustion data/performance from a laboratory study, a boiler simulation system (pilot combustor), and commercial boilers indicated the benefits of burning improved quality coal. The specific effects of cleaning are discussed. A validation of the necessity of commercial-scale and/or pilot-scale testing is presented.

Jan 1, 1988

By H. M. Roche

MAGNETITE mining and milling in the Eastern States in 1939 showed considerable improvement over 1938. For the first eight months of the year production of magnetite proceeded at a normal rate but operations were stepped up in the last four months owing to increased domestic demand. In New York, the Republic Steel Corp. operated the Witherbee-Sherman mines at Mineville throughout the year. Chateaugay Ore and Iron Co. operated their low-phosphorus mine at Lyon Mountain for the first seven months, but on Aug. 1, Republic Steel took over this mine -and have since operated it. In Pennsylvania, the Bethlehem Steel Co, operated the Cornwall mine continuously. In New Jersey, Mt. Hops and Scrub Oak were in operation all year. The Washington mine went into production on Nov. 1 and the Richard mine on Dec. 1.

Jan 1, 1940

By R. M. Barker

The historic Getchell property, near Golconda, NV, is being mined from the Getchell Main Under- ground workings, a footwall extension of the Getchell open-pit deposits along the Getchell fault. Drift-and-fill techniques are used to extract the ore through a ramp access. The adjacent Turquoise Ridge deposit is under development by two vertical shafts. These two mines will continue to provide feed to the Getchell's 2.9 ktld (3,200 stpd) mill/autoclave circuit. This will take Getchell Gold from its current production rate of 6.2 t/a (200,000 oz/year) to more than 12.4 t/a (400,000 oz/year) by 1999.

Jan 1, 1997

Sizing is fundamental technology for each step of ironmaking process. The progress of sizing technology has greatly contributed to the development of ironmaking technology. As the purposes of ironmaking operations diversified particularly since the oil crisis of 1973, the sizing technology made new advance- ment, as represented by pulverization of ser- pentine, dezincification and classification of secondary blast furnace dust, pulverized coal injection, size-segregated sinter charging and a coal preparation control process. These techniques are mostly characterized by the fine grinding of a given type of mineral or coal to heighten the degree of reaction con- trol. This trend is expected to continue Further.

Jan 1, 1984

By ERIIL SCHROEDTER

THE death, on May 6, 1908, of Dr. Hermann Wedding, Privy Mining Councilor of the Kingdom of Prussia, and Professor of the Metallurgy of Iron and Steel at the Royal Mining Academy of Berlin, was a loss keenly felt by the whole metallurgical world. Not alone in his native land, but also in foreign countries did he enjoy an esteem of which the title of honorary membership in the American Institute of Mining Engineers, the United States Association of Charcoal Iron-Workers, and the (British) Iron and Steel Institute bears eloquent testimony. Hermann Wedding was born March 9, 1834, in Berlin. At the suggestion of Dr. C. J. B. Karsten, the veteran father of Prussian metallurgy and author of the first German text-book of the metallurgy of iron, lie turned his attention, after gradu¬ating from the gymnasium, to mining and metallurgy. In 1853, he began a practical course at the Malapane iron-works, in Upper Silesia. Subsequently, he studied at the Berlin Mining Academy, and received from the University in 1859 the degree of Doctor of Philosophy. A journey which be made to England, somewhat later, led to his undertaking a German translation, with revision and additions, of John Percy's classic treatise on the metallurgy of iron and steel, the publication of which, in successive installments, stretched through many years. In 1863, lie published, as a thesis in connection with his "Assessor's examination," an essay, entitled The Results of the Bessemer Process for the Production of Steel, and Its Prospects for the Rhenish and Westphalian Iron and Steel Industry, which revealed such ability and knowledge as to secure for him a call to the chair of metallurgy in the Berlin Mining Academy.

Jun 1, 1909

By Charles Rubin

Mining is a capital- and labor-intensive business, and profitability often depends on the ability to squeeze maximum efficiency out of every piece of equipment to achieve safe production. This means keeping every mechanized drill, loader, truck and bulldozer operating at all times, and having a system to coordinate the movements of people and personnel. Mines often use wireless radios to connect equipment with management systems. But growth and changes in a mine?s profile over time can require upgrades to the wireless network. In its openpit gold mine near Carlin, NV, Newmont Mining Corp. has recently upgraded to microwave radio systems to increase bandwidth while maintaining round-the-clock uptime on its wireless network. For many of its operations around the world, Newmont uses Minestar, an operational control software system that allows administrators to dispatch equipment operators and use GPS to track the precise position of every piece of equipment in an operation. Each of the approximately 150 pieces of equipment at the mine has a radio on board. These radios connect to a network backbone that carries information between the equipment and the mine?s operations center. When traffic began to bog down on this network, Newmont upgraded to Exalt microwave backhaul systems to carry dispatch, inventory and control information throughout its operation.

Jan 4, 2010

By W. A. McKinney

In conventional dump leaching of porphyry mine strip wastes, many years are required to extract up to 20 percent of the copper from the contained sulfide minerals. Furthermore, none of the molybdenum, gold, or silver in the strip wastes is recovered by current leaching practices. Because mineralization occurs predominately along fracture planes, breaking of the rock during mining operations liberates and concentrates some of the metal values in the fines. Research shows that upgraded fines can be screened from mine wastes and froth floated for early recovery of copper, molybdenum, gold, and silver. For example, screening a dump sample assaying 0.35 percent copper as chalcopyrite removed about 20 percent of the copper as minus 1/4-inch material that analyzed 0.6 percent copper. About 35 percent of the molybdenum and 20 percent of the gold and silver also reported in the fines. Crushing the mine dump sample to minus 3 inch before screening increased the distribution of copper and molybdenum in the minus 1/4-inch screen fraction to 28 and 50 percent, respectively. Similar results were obtained by screening fines from two other large samples of mine waste dump materials. Flotation studies established that the enriched minus 1/4-inch fines from the three dump samples could be effectively concentrated. Comparative testing revealed that the combination of froth flotation of fines and acid-ferric sulfate leaching of the coarser fraction enabled doubling the recovery of copper over direct leaching of the samples. In addition, significant amounts of molybdenum, gold, arid silver were recovered by flotation.

Jan 1, 1970

By Kenneth L. Myers

The net balance of the inflow and outflow of water in a tailings storage facility has major economic implications in any large mining and milling operation. In a net precipitation environment it can control the ultimate size and storage capacity of a facility or dictate the need for an expensive treatment and discharge program. In a net evaporation environment it can control the extent of the water rights acquisitions required for makeup water and dictate the number and size of expensive wells and pumping and delivery systems. The elements considered in a water balance analysis include the anticipated production rate, the water content of the slurry used to deliver the tailings, inflow from precipitation and snowmelt, and losses from evaporation and seepage. The mine can exert significant control over only one of these elements: the production rate. All others are subject to considerable uncertainty from month to month and year to year. The traditional approach is to analyze in a spreadsheet environment by making simplifying assumptions and using monthly mean or "average" values for precipitation inflows and evaporation losses. Often the analysis will be repeated with values subjectively assigned to represent a "wet" year or "dry'' year. The probabilistic approach uses the same basic spreadsheet model in conjunction with a probabilistic simulation add-in program allowing probability distributions to be substituted for any of the deterministic variables. The resulting analysis shows the full range of variation possible for each parameter of interest (i.e., available return water, makeup water required, storage, seepage losses) and estimates the exceedance probabilities for each. The potential uses and advantages of the probabilistic approach are discussed.

Jan 1, 1992

By J. Mosher, G. Banini, J. Hollow, A. Villanueva

Prior to installation of High Pressure Grinding Rolls (HPGR) at PT Freeport Indonesia (PT-FI) a series of laboratory tests were carried out to determine the design parameters and also determine key performance indicators (KPIs) for the industrial unit. The design parameters derived from the lab test work were then scaled up to estimate the industrial capacity of the HPGRs to be installed. These parameters include specific power draw, specific throughput, and specific force, rolls speed, product size distribution and wear rate of the rolls. This paper compares the performance of the scale-up procedure against the installed industrial size HPGR. Overall, the specific throughput of the industrial size HPGR is higher by a minimum of 30% compared to the expected scale-up value. As a result of the high specific throughput, the specific power draw and grind sizes are below the scale-up expectations in the commercial application. The impact of these factors also contribute to a lower than expected wear rate on the industrial rolls. Installed rolls achieved a service life in excess of 18,500 hours relative to the target of 6,850 hours predicted from the laboratory testing.

Jan 1, 2012

By B. P. Mohanty, D. A. Shores

During the induration of fluxed taconite pellets, alkali salts deposit on the grate support bars, causing severe corrosive degradation of these alloys. To determine the source of these deposits and to understand the mechanism by which the salts are conveyed to the grate bars, a study of the reactions between fluxed pellets and combustion gas was carried out. The study focused on the thermodynamics and kinetics of several processes associated with induration; namely, oxidation of magnetite, calcination of flux, and the formation and gaseous transport of various alkali salt species. Both theoretical and experimental techniques were used. It was concluded that the principal source of alkali salt deposits is alkali chlorides, which are present as contaminants in the flux and/or residue from contaminated washwater. The pathway from pellet to grate bar involves the following steps: evaporation of chloride salts within the pellet; diffusion of salt vapor out of the pellet, aided by the outflow of CO2 from calcination of the flux; convective transport by the combustion gas with concurrent (partial) conversion to alkali sulfates by reaction with residual SOX in the combustion gas; and condensation of salts on the grate bars.

Jan 1, 1998

By Jae-Chun Lee

Di-2-ethylhexyl phosphoric acid (D2EHPA) is widely used for separating rare-earth elements. In commercial plants, rare-earths are usually stripped from loaded extractant streams using mineral acid, then precipitated as oxalates. Many rare-earth uses demand specific powder characteristics, which are obtained by secondary processing. This paper demonstrates the feasibility of combining the stripping, precipitation and powder processing stages, thereby achieving considerable savings. MEHPA solutions were loaded with yttrium, then emulsified with oxalic acid-HC1 solutions to precipitate yttrium oxalate, which was readily calcined to yttrium oxide. The precipitation kinetics and yield were sensitive to process conditions. The morphology and size of the yttrium oxalate powders varied with the concentrations of D2EHPA and oxalic acid, and the presence of SPAN 60, which affected nucleation, growth, and the emulsion characteristics.

Jan 1, 1992

By Diane Germain, Normand Tassé, Claude Dufour

At the East Sullivan site, pore-waters underlying a wood waste cover that prevents sulfide oxidation are characterized by an anoxic environment, abundance of dissolved organic substrates, and near neutral pHs. Such conditions favor sulfate reduction and base metals precipitation as sulfides, as well as carbonate-metal precipitation. Pore-water composition from 1992 to 1998 shows a significant Fe2+ decrease. Therefore, the restoration strategy of that site capitalizes on these alkaline and reductive properties. Since 1998, a novel treatment of acid effluents, based on the recirculation of water discharged around the impoundment through the organic cover, is tested on the site. Available data gathered in 1998 and 1999 shows that the pH of recirculated water flowing within the wood waste cover increases by 2 to 4 units and that Fe,, concentrations decrease by a factor greater than 6.

Jan 1, 2000

By Eduardo Lozano, Vilem Petr

This study demonstrates the ability of high-order, shock-capturing methods to simulate detonation wave propagation in right circular cylinders of non-ideal explosives. 2-D axisymmetric, reactive Euler equations were solved for the detonation of the highly non-ideal explosive ammonium nitrate-fuel oil (ANFO) using a simple pressure-dependent rate law and perfect gas equation of state. The fractional step method was applied to the convection and reaction operators using a 2nd-order Strang splitting. The flow solver consisted of a finite difference scheme where the flux is reconstructed by a modified fifth-order weighted essentially non-oscillatory (WENO5-Z) with local characteristic decomposition and local Lax-Friedrichs (LLF) flux splitting. Time integration was performed by a third order total variation diminishing (TVD) Runge-Kutta time discretization method, also known as the strong stability preserving (SSP) method

Jan 1, 2019

By A. Kounosu, T. Fujita, J. Shimoiizaka, K. Nakatsuka

Stable aqueous dispersion of magnetite colloid of about 10 nm in diameter was obtained by allowing an anionic or nonionic surfactant to adsorb on the hydrophobic surface of magnetite particles prepared by monomolecular adsorption of oleate. Sodium dodecylbenzene sulfonate, sodium oleate and poly (oxyethylene) nonyl phenyl ethers whose hydrophilic-lipophilic balance (HLB) are higher than 12 were suitable for giving a second adsorption layer to obtain a stable dispersion. Stability of the colloidal suspensions depends upon pH of the solution and is controlled by the dissociation of the adsorbed surfactant in the second layer. The addition of ethyleneglycol, which was used for lowering the freezing point of the dispersion, did not affect the stability when used in amounts smaller than 60% of water. Preparation of diester-based ferrofluids was also attempted by the same procedure using a nonionic surfactant as second layer molecule. Hydrophobic magnetite colloid, which had been preliminarily coated with mono-molecular oleate, was suspended in di(2-ethylhexyl) agipate, azerate, and sebacate respectively, and dispersion stability was investigated by adding various poly (oxyethylene) nonyl phenyl ethers of different HLB values. It was found that those with HLB values between 10.9 and 13.3 were suitable for this purpose. Stabilities of the dispersions in a magnetic field were investigated up to 1 T by applying an electromagnetic field. No separation of dispersant was observed and each magnetite dispersion displayed the characteristics of a magnetic fluid.

Jan 1, 1980

By M. G. Cheney

The purpose of this paper is to review the more important developments in the production of petroleum during 1930 in Texas, excluding the Panhandle and Gulf Coast districts, giving emphasis to trends rather than to statistics. Outstanding Developments Aside from increasing curtailment of drilling operations and general prorating of production by state authority the most noteworthy developments for the year appear to have been: 1. Demonstrations of the fictitiousness of potentials as shown first by Darst Creek pool, rated at 180,000 bbl. and having actually 78,000 bbl. daily, and especially by the Hendricks pool of Winkler County, with potential of about 1,000,000 bbl. daily in mid-year and production of only 52,000 bbl. daily when opened to continuous full production in December. 2. Rapid development of the Darst Creek pool under competitive drilling. 3. Orderly and highly successful development of the Van pool under unit operation. 4. Failure of several highly rated structures southwest and northeast of Van. 5. Extension of the deep Simpson production at Big Lake and increased interest in these pre-Mississippian pays in North Central Texas and West Texas. 6. Discovery of prolific wells in northwest Rusk County from sands of Upper Cretaceous age, portending a rapid and extensive development campaign around the northwest margin of the Sabine uplift. North Central Texas It appears logical to discuss the new developments by districts as set out by the American Petroleum Institute, but North Texas and West Central Texas districts will be treated together. Pre-Mississippian,.—The pre-Mississippian beds, which in previous years yielded a few large wells in Young, Cooke and Callahan counties,

Jan 1, 1931

By Balesh W. Konda, Andrew B. Cecala

Face ignitions occurring during longwall mining are increasing each year and are expected to continue to increase as deeper and gassier seams are mined. Effective methane monitoring strategies are needed to supplement techniques developed either to control the ignition sources or to dilute the gas to an acceptable concentration. Present monitoring strategies do not always detect dangerous concentrations as rapidly as they should. In a number of instances, dangerous concentrations have been observed at the shearer, but are diluted to acceptable levels when measured at the tailgate monitoring location. To effectively monitor and control methane concentrations, methane liberation and emission patterns must be identified. This need has led to a joint research effort between the Canada Centre for Mineral and Energy Technology and the United States Bureau of Mines. By combining the knowledge and experience of both organizations, the methane hazard facing underground longwall operations can be addressed more effectively. A comprehensive plan was developed to monitor methane levels throughout the panel and for an entire longwall mining cycle. In June-July 1986, a case study was performed at the Cape Breton Development Corporation's Lingan colliery in Sydney, Nova Scotia. This initial study was performed on two advancing longwall panels. Methane concentrations and flow patterns from this study are described in this report. A similar study is planned on a retreating longwall panel.

Jan 1, 1987

By K Nilsson, D Connelly

Troy Resources acquired the Karouni Gold Project in Guyana, South America in 2014 and immediately proceeded to a Pre-Feasibility Study and project implementation. The study considered two open pit mines feeding a conventional carbon in leach (CIL) gold plant with a capacity of 1Mtpa. The study assumed a total of 2.61 million tonnes of ore with an average grade of 3.84 g/t gold with a recovered gold production of 303,526 ounces over a three year mine life.The project development involved drilling metallurgical test holes, securing second-hand major pieces of equipment where suitable, and arranging shipping to Guyana. The remote location meant logistical considerations were paramount. The plant consists of conventional two-stage crushing with single stage ball milling and a gravity circuit. The tailings circuit includes DETOX.The extremely high rainfall presented challenges with water management and the necessity to dispose of clean water to the environment. The DETOX was also mandatory due to the highly sensitive environment and past history in the area. The criticality of this meant that in the design, any cyanide in the tailings would precipitate in a plant shutdown.Lessons were learned and the project has been both profitable and successful for Troy Resources in a new operating location. In addition, the project has created jobs, delivered royalties and brought new skills into an area where previously there was little current mining activity.CITATION:Nilsson, K and Connelly, D, 2015. Karouni Gold Project from drill core to commissioning, in Proceedings MetPlant 2015, pp 197–206 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

By Victor E. Kral

"INTRODUCTION The Segerstorm-Heizer property was examined by engineers 3/ of the Bureau of Mines in May and June 1942 and Mach 1943. As a result of these examination, the Nevada State Department of Highways,constructed 9.3 miles of graveled road under the mine access-road program. A magnetometer survey was made by the Geophysical Division 4/ in October 1943, and as a result the Mining Branch set up and conducted a core-drilling,project. Work on the deposit started May 24, 1944, and was suspended on July 31, 1944, but was resumed on December 4, 1944 and continued until completion on March 27, 1945.ACKNOWLEDGMENTSIn its program of exploration of mineral deposits, the Bureau of Mines has as it, primary objective the more effective resource to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as soon as practicable after its conclusion. The Mining Branch Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploration work, and prepares the final report. The Metallurgical Branch, R. G. Kinickerbocker, chief analyses samples and performs beneficiation tests."

Mar 1, 1947