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By K. J. Stanaway

Major world ilmenite and rutile accumulations reveal similar regional geology and Proterozoic age deeper crustal source rocks. During crustal collision titanium crystallizes as ilmenite and rutile at buried sites of high pressure and temperature rock metamorphism. Hydrothermal activity can convert titanium minerals to rutile, but titanium migration and enrichment seem only local. Many melts crystallize rocks with iron-titanium oxides in solid solution, but titanium enrichment at economic scale takes place in basic intrusive melts often associated with anorthosites and charnokite. Sedimentary placer enrichments have formed since the Proterozoic with water-resistant ilmenite, and rutile segregating by gravity from quartz sands deposited from flowing water. Placers have residual, alluvial, strand and shallow marine variants. Time, organic acids, and sand permeability play lead roles in the leaching of iron from ilmenite during weathering and diagenesis.

Jan 1, 2005

By Evan J. Owen, Virginia T. McLemore

The Zuni Mountains, located in Cibola County, New Mexico is an uplifted area that exposes Proterozoic igneous and metamorphic rocks overlain by Permian and younger sediments. Sedimentary-hosted Cu deposits and fluorite veins in the district have recorded production, but other deposits exist. Proterozoic ultramafic rocks may host Ni and PGE. A recent regional stream sediment survey collected 76 samples as part of an exploration geochemistry course at New Mexico Tech with the goal of assessing the critical minerals potential of the district. Whole rock and trace element chemistry of the sediment samples (<2 mm) show a variety of critical minerals possibly worthy of future targeted exploration including up to 700 ppm As, 2100 ppm Ba, 26 ppm Bi, 25 ppm Co, 640 ppm Cu, 145 ppm Ni, 110 ppm Sb, 170 ppm V, and 500 ppm Zr. Positive correlation between Bi, As, Cu, and Sb suggest that these critical minerals are found together within copper veins related to shear zones in the district. Samples collected from streams that drained outcrop of mafic and ultramafic rocks were found to generally contain more Ni, Co, and V. Samples elevated in Ni will be reanalyzed for PGE.

Feb 1, 2025

By E. A. Sigworth

Our interest in metallurgical applications for activated carbon was thoroughly aroused when laboratory studies indicated that each dollars worth of carbon could retain as much as four dollars worth of tin. Since then other data was developed suggesting many Potential uses in the metallurgical field it is hoped that, the information presented in this paper may encourage studies by knowledgeable individuals in metallurgical operations. Activated Carbon accomplishes its results by adsorption which involves selective removal of materials from solution by holding the compounds on the carbon surface at the active areas. An example of adsorption is the dyeing of cloth where the dye is selectively held on the cloth surface and the concentration in the dye solution is thereby reduced. Many theories exist on, adsorption, but the predominant factors involved in metallic ion adsorption probably are that adsorption is indirectly proportional to solubility and is benefited by high concentrations acting to squeeze out molecules in smaller amounts.

Jan 1, 1962

By Jerry Dolph

In September 1855, 55-year-old Noah Spencer Kellogg and his $3 jackass named Bill discovered what was known at the time as a “blow out” of high-grade lead and silver ore. The deposit was located on the side of a North Idaho mountain high above the South Fork of the Coeur d’Alene River. The ore was later assayed at 41,141 g/t (1,200 oz/st) silver. Kellogg named his discovery the Bunker Hill Lode, after the June 17, 1775 Revolutionary War battle of Bunker Hill. A thriving pioneer settlement sprang into existence around the resulting mine’s workings and was eventually— and appropriately — named Kellogg. The peak rising hundreds of feet above the mine’s adit was named “Jack-ass Peak” after Noah Kellogg’s hairy companion.

Jan 1, 1996

By S. A. Osterberg, J. L. Breckenridge, R. S. Popielak

Multidisciplinary investigations were completed to prove the availability of water resources for the proposed San Cristóbal silver-lead-zinc mine in the arid Altiplano of Bolivia. Surface water resources are scarce, of poor quality, and unsuitable for development. Therefore, hydrogeological reconnaissance targeted alluvial aquifers for development. Follow-up resistivity, refraction, and water quality assessments were used to prioritize areas with prolific production potential. Pumping tests and regional water balance analysis indicate an alluvial aquifer can sustain the required approximately 40 000 m3 per day production for the life of the mine and predict no significant negative environmental effects on local groundwater users and the environment.

Jan 1, 2002

By R. J. Snoby, J. K. Alderman

Although once fairly common as a method of coal preparation in the United States, dry cleaning has virtually disappeared. Low-rank coals used for power generation in the western U.S. are suited for dry cleaning because water has limited availability in the American west. Surface moisture added through wet cleaning offsets energy improvement achieved from mineral matter reduction. Information will be presented on the commercial application of dry cleaning in North America, the historic development and current status of the technology, and the introduction of modern processing theory and control technology to the design of dry cleaning equipment and plants.

Jan 1, 2001

By Kim Appleby

Epithermal gold-silver (lead-zinc-copper-manganese) mineralization on Misima Island is confined to steep and reactivated flat-lying normal faults in the upper plate of a major, shallowly dipping detachment fault. The hangingwall comprises an Eocene metavolcano-sedimentary sequence that has been extensively intruded byMiocene calc-alkaline granodiorite. It is unconformably overlain by Pliocene sedimentary and volcanic rocks. High-pressure amphibolite facies rocks dominate the footwall and have many characteristics of a metamorphic core complex. Mafic-alkalic lamprophyre dike swarms intrude the hangingwall and footwall sequences. Previous workers attributed the gold-silver mineralization on Misima to the intrusion of the porphyritic granodiorite (Williamson, 1984). This has been proposed for many tertiary gold deposits of the southwest Pacific(Sillitoe, 1989; Leach and Corbett, 1994).

Jan 1, 1996

By Refik Elibay, Lawrence A. Williamson, George D. Barnes

Under an extremely aggressive schedule, final design of 13.5 km (8.4 miles) miles of 8.2 m (27 ft) diameter deep rock tunnel, 322 ML/day (85 million gallons / day)submersible pumping station and associated facilities were accomplished ahead of a federal court mandated consent decree schedule. Challenges overcome by the project team in enabling timely completion of the construction documents will be presented. Discussion includes evolution of final design, consideration of future O&M requirements, and risks identified for construction and operations, together with measures to manage and proactively prepare for such risks.

Jan 1, 2005

Extending an organization?s knowledge base throughout the entire enterprise can improve operations. Until recently, though, field operations were often left out of the information loop, as extending high-bandwidth communications into harsh environments often proved impossible due to thermal extremes, physical hazards and caustic chemicals. However, advances in the design and manufacture of rugged fiberoptic cables have now enabled the successful installation of 10-gigabit transmission links to places such as mining operations. The experience of Consol Energy exemplifies how plant managers can successfully enlist ruggedized tight buffered cables to help carry the efficiency of ERP communications into even the most challenging work environments. ?As part of our ERP implementation, we extended our corporate network underground into our mines using fi beroptic cable,? said Tom Prokop, manager-site support for Consol Energy. ?We?ve actually had rooffalls bury the cable between rocks and still did not lose data communications. Our maintenance personnel are now able to access our ERP system while underground at locations that can be up to 32 km (20 miles) away from their desks or the warehouse. Access to the corporate network allows them to order parts, look at electronic schematics, access monitoring data, no matter where they are in the mine. With a few hundred workers below ground, this immediate access translates into a time-savings that adds up in a hurry.?

Jan 1, 2009

By E. Tondu

Separation Technologies Inc.’s (STI) electrostatic separation technology is a dry, continuous process for the separation of discrete particles. This high-volume process does not require any additives nor is any additional waste produced. In December 1993, STI, in cooperation with New England Power(NEP), installed an 18-t/h (20-stph) prototype electrostatic separator at NEP’s Salem Harbor plant. The plan was to convert waste streams of type F fly ash into commercially valuable products. In July 1995, a second separator was installed at NEP’s Brayton Pointplant. Fly ash feed, ranging from 6% to 25% carbon (loss-of-ignition fly ash or LOI), is separated into <3% LOI “clean” ash and sold as a portland cement substitute in the New England concrete markets.

Jan 1, 1996

By Richard A. Levins

The imposition of non-market regulations, such as the proposed SO2 standards for coal combustion, will typically lead to less efficient (thus more costly) production in a free enterprise system. For the coal industry these increased costs will occur in several ways, among which are mining less accessible low sulfur reserves and transporting low sulfur coal to distant markets. There are, of course, social benefits of reducing the S02 emissions from the use of high sulfur coal. The social benefits include decreased health risks, reduced damages to property, and certain unmeasurable benefits associated with the aesthetic appeal of clean air. Proponents of Federal S02 standards argue that the benefits gained from reduced emissions will exceed the costs borne by the coal industry and society in general in meeting the regulations. The purpose of this paper is to investigate the degree to which costs of meeting future energy demands from coal will change under different sulfur standards. No attempt is made to estimate the benefits of imposing regulations. Specifically, the impact of SO2 standards on the private costs of meeting regional coal demands, the competitive positions of the nation&apos;s major coal producing regions, the degree to which strip mining as opposed to underground mining will be feasible, the amount of coal being processed, and the amount of coal transported over major rail routes will be analyzed.

Jan 1, 1976

By Ian McFeat-Smith, Odd G. Askilsrud

Introduction Given the mountainous nature of the local igneous terrain, hard rock tunnelling plays an important role in the development of Hong Kong&apos;s infrastructure. In 1990, tenderers for two tunnel projects were encouraged to consider using hard rock TBMs, the territories&apos; first. As a result the 7.5km long, 3.56m diameter Tolo Effluent Tunnel and the 5.3km long, 4.8m diameter Hong Kong Electric Cable Tunnel were excavated by hard rock TBMs. The successful completion of both projects in 1992 should make the TBM method an attractive construction alternative for planned, upcoming projects in Hong Kong. Tunnelling Conditions Tunnelling solutions are frequently adopted in Hong Kong due to the intensity of development, lack of flat landscape and proximity of mountainous terrain to the main centers of population. This is carried out primarily in granites or granitic-type rocks which surround Victoria harbour, and to a lesser extent in the outlying volcanic rocks which include extremely hard tuffs and lavas. Tunnelling will generally take place in granitic rocks, normally about 100-250 MPa in strength, and with an average joint spacing of 0.3m and a quartz content of 30-

Jan 1, 1993

By D. Tao

The presence of insoluble slimes in potash ore poses a serious processing problem to the potash industry. These insolubles must be removed prior to potash flotation because of their high adsorptive capacity for amines which are generally used as collectors in the subsequent sylvite flotation. This is usually accomplished by scrubbing of the ore in brine followed by hydrocyclone classification to separate slimes from the salt particles. Insoluble slimes that remain in the ore after the desliming procedure are depressed by reagents such as guar gum or starch during sylvite flotation. In this research, the feasibility of using GP clay binders to replace guar gum for potash flotation was investigated. Batch mechanical flotation tests were conducted with the potash samples provided by a leading potash company. It has been found that GP clay binders increased potash concentrate yield and recovery at the same product grade. Effects on potash flotation efficiency of flotation process parameters such as impeller rotation speed, slurry temperature, binder type, dosage and conditioning time have been investigated to establish the optimum conditions for flotation. Binder GP374G33 has been identified as the optimum substitute for guar gum as slime depressant in potash flotation.

Jan 1, 2008

By Hang Yang, Linneas W. Laage

A major concern of mine fires is the heat generated ventilation disturbances which can move products of combustion (POC) through unexpected passageways. Fire emergency planning requires simulation of the interaction of the fire and ventilation system to predict the state of the ventilation system and the subsequent distribution of temperatures and POC. Several computer models were developed by the U.S. Bureau of Mines (USBM) to perform this simulation. The most recent, MFIRE, simulates a mine&apos;s ventilation system and its response to altered ventilation parameters such as the development of new mine workings or changes in ventilation control structures, external influence such as varying outside temperatures, and internal influences such as fires. Extensive output allows quantitative analysis of the effects of the proposed alteration to the ventilation system. This paper describes recent USBM research to validate MFIRE&apos;s calculation of temperature distribution in an airway due to a mine fire, as temperatures are the most significant source of ventilation disturbances. Fire tests were conducted at the Waldo Mine near Magdalena, NM. From these experiments, temperature profiles were developed as functions of time and distance from the fire and compared with simulations from MFIRE.

Jan 1, 1995

By Ing Newton Amegbey, Joseph Afari Idun

Ashanti Goldfields Corporation (Gh) Ltd., the leading gold mining operation in Ghana is embarking on a major rehabilitation and expansion programme to increase gold production. A new southern ventilation district was targeted for this programme, and the ventilation system was to be reviewed in order to cope with increased production. The southern ventilation district was previously ventilated by booster fans. This arrangement was however, inadequate to solve the problem of the need to reduce smoke clearance time of the production areas, and to generally improve the underground ventilation conditions. Fan maintenance costs increased with the number of fans installed in the booster fan arrangement, and the fact that the fans were installed underground made maintenance difficult and took longer time. It became necessary to consider the installation of a new main fan on the surface. This paper gives an overview of the ventilation systems of the southern ventilation district of the mine before and after the new main fan was installed. The field tests carried out on the fan to ensure that it complied with supplier&apos;s specifications are described, and the new system analysed to see it&apos;s effectiveness.

Jan 1, 1993

By Kumara S. Rachamalla

Mineral activity in Ontario represents an annual production in excess of $4 billion. The Ontario government encourages the mining industry to undertake mineral development through grant programs and incentives offered by mineral resource taxation. Computers are playing an increasingly important role in improving productivity in the administration of incentive programs and the Mining Tax Act in Ontario. This has meant speedier processing of grant applications and tax returns which is resulting in a streamlined approach to incentives and taxation in Ontario. The use of computers has resulted in significant contributions to key areas of concern such as assessment of mining tax returns, analysis of the changes, if any, to the Mining Tax Act and modeling of the Ontario Mineral Exploration Program (OMEP). Implementation of state-of-the-art technology such as Local Area Networks (LAN&apos;s), fourth generation languages and integrated micro-mainframe information processing has resulted in improved productivity as well as lower costs. As a result, the respective services provided to the mineral industry by these two programs are now delivered in an efficient and cost-effective manner utilizing the latest available computer technology.

Jan 1, 1986

By S. A. F. Murrell, M. Hong, L. J. Bond

This paper investigates the propagation, interaction and scattering of explosively generated seismic waves with discontinuities in rock masses using numerical models which employ a finite difference method. The models consider 2-D systems and give a full solution including mode-conversion in the mid-frequency scattering region where feature dimensions are of the order of the wavelengths involved. The paper has two parts, the first of which considers wave propagation and diffraction by simulating an explosive body source in a half- space containing a step or a slot on the surface which represent a cliff and a rift valley that has dimensions of the order of the wavelengths in the source. The second part of the paper reports a hybrid technique which combines a perturbation method and the finite difference method for wave propagation again caused by an explosive body source in a 2-D half-space system but with a shallow surface obstacle, such as a smooth ridge, with elastic constants slightly different from bulk material and the slope of this surface topography are shallow. This hybrid technique is also reported being applied to a half-space with a horizontal void or insert.

Jan 1, 1986

By Euler De Souza, Jason Chew, Aldrich Philip Dirige

Sillmats are structural elements upon which the safety and economics of underfill mining or sill pillar recovery in stopes of moderate width with steeply dipping ore zones, depend. The traditional stability design of cemented sillmats appears to have developed from experience and from standard static physical model tests such as uniaxial and triaxial compression. Such standard static physical model testing approach arrives at some approximate parameters, normally used to describe or predict the behaviour of sillmats in analytical or numerical models. This approach offers inherent limitations and generally results in conservative designs. Centrifuge modeling studies are combined with numerical modeling in this paper to provide insights into sillmat strength behaviour. The results of both modeling techniques suggest that, in stopes with smooth rock wall conditions, sillmat failure is driven by the fill self-weight and has minimum dependency on the fill binder content. In stopes with rough rock wall conditions, however, the wall roughness contributes significantly to the stability of the sillmat during underfill mining. This study indicates that the stability of paste fill sillmats can be designed with confidence using centrifuge physical modeling in combination with numerical modeling.

Jan 1, 2001

By G. J. Olson, K. S. Noah

A combined physical/biochemical process for the precombustion removal of 13 inorganic hazardous air pollutant (HAP) precursors, i.e., Sb, As, Be, Cd, Cr, Cl, Co, F, Pb, Hg, Mn, Ni and Se, from coal was tested. Biochemical processes for removal of HAP precursors from coal potentially offer advantages of deeper cleaning, more specificity and less coal loss. The slurry column is a second-generation process for the beneficiation o f fine (60-mesh x µm coal by a combination of physical separation of mineral matter and biooxidation of pyrite. Sixty-seven percent removal of pyrite from a 60-mesh Pittsburgh #8 coal was achieved at a 35% (w/w) slurry concentration and a five-day reactor residence time. Ninety percent of the heating value of the feed coal was recovered. Among the HAP precursors of most concern, over half of the Se, As and Hg were removed from the feed coal. From 40% to 70% of most HAP precursors were removed from the feed coal. Hg in the feed coal was reduced from 0.12 to 0.054 ,µg/g in the product coal, while waste coal contained 0.24 µg/g.

Jan 1, 2000

By T. J. Cox

The Red River is located within the Sangre De Cristo Mountain Range in northern New Mexico. An approximate 12-mile segment of the river from the town of Red River to the village of Questa (Questa) includes several hydrothermal alteration zones. Alteration ?scars? formed as a result of rapid chemical weathering and physical erosion of pyrite-rich hydrothermally altered rocks. Storm water runoff from the scar drainages contributes metal-laden, acidic water to the river and creates a visible plume of discolored water in the river. Acidic runoff reduces the river pH from 7 to the mid 3s for at least 2 hours during large storms and the low pH water continues downstream. Runoff from scar drainages increases some metal concentrations in the river from below chronic ecological criteria to as much as two orders of magnitude greater than acute ecological criteria, and results in acutely toxic conditions for macro-invertebrates. A general improvement in the river?s water quality occurs downstream due to dilution from tributary inflow from non-mineralized watersheds, the natural buffering capacity of the river, and storm water controls at the Chevron Mining Inc. Questa mine.

Jan 1, 2011