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By R. B. Hawkins

The discovery of the gold deposits of the Jerritt Canyon district and the construction of the E. R. Bell Mine is one of the significant mining developments in the United States during the past ten years. This mine will exploit one of the larger deposits of disseminated gold presently known, with proven, recoverable reserves in excess of 67.6 million grams of gold. Interest generated by the success of this project has contributed greatly to the tremendous resurgence in exploration for disseminated gold deposits in Nevada and throughout the west. The Jerritt Canyon project, including the Bell Mine, is a 70/30 joint venture between Freeport Gold Company and FMC Gold Incorporated, both of which are wholly owned affiliates of the respective parent companies, Freeport-McMoRan, Inc. and FMC Incorporated. Under the terms of the joint venture agreement, Freeport Exploration Company, another Freeport-McMoRan affiliate, manages the exploration and pre-mine development. Drilling, design, construction and management of the Bell Mine are provided by Freeport Gold Company.

Jan 1, 1982

By MOHAMED WAEL, ANASTASIA GOEVA, ABDULAZIZ TAWFEEQI, IHTISHAM TARIQ, S. M. ZAKIR HOSSAIN, NIAZ ALI KHAN, MUHAMMAD FAISAL IRFAN

Carbon dioxide (CO2) mineral carbonation is a carbon capture and storage (CCS) technique that can sequester CO2 permanently in the form of durable carbonate minerals. Extendable permanent storage capacity — onshore and offshore storage reservoirs — and the exothermic nature of the mineralization process make this technique attractive [1]. In the present study, maximum carbonation efficiency for aqueous mineral carbonation was achieved through two steps: optimization of calcium leaching from cement kiln dust followed by the reaction of pure CO2 with the calcium hydroxide precipitates formed by hydroxylation using sodium hydroxide (NaOH). Optimization of calcium leaching is highly important, as it is a rate-limiting reaction step in mineral carbonation and also influences and enhances the carbonation efficiency. To maximize the calcium leaching as well as carbonation efficiency, response surface methodology — with either Box-Behnken design or central composite design — was applied. It is the most well-known statistical, fully randomized and bias-free method for determining optimized conditions using quadratic regression models.

By Tedd B. Bodimer

Why complicate an already complex machine such as a continuous miner by adding roof drills? Immediate permanent roof support is an immediate thought of the mining engineer just as elimination of frequent time-consuming places changes is a thought of the methods engineer. The realization of those two objectives has the potential for improved safety with increased production is the thought of the general manager. Miner-Bolters Used a Generation Ago These are not new thoughts as the 1CM continous miner equipped with two integral roof drills was introduced twenty-five years ago. Approximately two hundred of these machines were sold in the next five years for use in medium and high seam operations. The 1CM miner chassis that remained stationary in the center of an entry or room while the ripper bar was swung and sumped hydraulically provided an ideal platform for mounting two roof drills that could be operated during the continuous miner's production cycle. Two roof bolts could normally be installed in less time than required for the mining cycle. A typical roof drill unit is shown in Figure I.

Jan 1, 1981

By Ronald R. Bauer

Wollastonite is a little known industrial mineral of the silicate group. The largest and purest known deposit in the free world is being mined and beneficiated in Millsboro, New York by NYCO, A Division of Processed Minerals Incorporated. The associated garnet and diopside are separated from the wollastonite using dry high intensity magnetic separators. Beneficiated wollastonite is used extensively as an additive and filler in the ceramic, paint, refractory, and wallboard industries. Wollastonite acts as a functional filler due to its unique chemistry and physical acicularity.

Jan 1, 1982

By YONGQIONG YANG, Ning Wang, CHONGGUANG LUO, LI ZHU, Hanjie Wen, SHENGJIANG DU, Hannian Gu

Kaolin clay from Late Permian sequences has been considered a potential resource for niobium (Nb) due to high concentrations reported at several hundred micrograms per gram and large areal distribution. A previous case study identified titanium (Ti)-bearing minerals associated with kaolin clay as the main host phases for niobium. Correlation between the Nb and Ti concentrations was poor, however, and the types of Ti-bearing minerals and modes of Nb occurrence were unclear. To investigate this, typical kaolin clay samples from Late Permian sequences in southwest China were characterized, and final products derived from them were investigated using X-ray fluorescence (XRF), inductively coupled plasma-mass spectrometry (ICP-MS), X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy-dispersive X-ray spectroscopy (EDS). The results revealed three types of titanium dioxide (TiO2) mineral phases in the clay samples: (1) massive TiO2 minerals, (2) aggregates of nano TiO2 minerals and (3) granular TiO2 minerals. The first two did not contain niobium. From the EDS analysis, the granular TiO2 minerals, including anatase and rutile, were the source of Nb in the kaolin clay samples. 

By BHAMIDIPATI S. SASTRY, KATTAMURI PAVAN KUMAR, ADITYA PANDEY

Several laboratory methods are available to determine the thermal conductivity of rocks, but most of them are complex and cumbersome. The present study explains the working principle of Lee’s apparatus, which is relatively simple, easy to fabricate and use, and provides consistent results. In the present study, thermal conductivities of sandstone cores obtained from an Indian coal mine are determined using Lee’s apparatus. An approach is discussed to determine the temperature gradient of sandstone specimens while cooling and is used to calculate thermal conductivity. The thermal conductivities of different sandstone specimens have values between 2.37 and 2.59 Wm−1°C−1. For different sandstone cores obtained from the field, properties including specific gravity, specific heat capacity, thermal diffusivity and porosity, along with thermal conductivity, were determined and highlighted in this study.

By Gregory Rumbaugh, Christopher Mark

Recent pillar collapses have caused five large airblasts in underground U.S. limestone mines. One of these events injured three miners, but all of them put many other miners at risk. To better understand the hazards, Mine Safety and Health Administration (MSHA) conducted a comprehensive review of the international literature on airblasts. More than 40 airblast cases have been documented, in a wide variety of minerals. Experience shows that miners that are in the direct path of the air as it moves towards the mine exits are at the greatest risk. The paper describes a risk management methodology that can be used to evaluate the level of hazard throughout the mine and aid in the selection of controls to reduce the risk. The paper concludes with a detailed case history of an actual pillar collapse and airblast.

By Robert R. French

Commercial grade gypsum beds up to 16 feet thick is present in southwestern Indiana. The major deposits are found at a depth of 350 feet to more than 500 feet below the surface. The ore body averages about 75 to 95 percent gypsum. Two companies are currently exploiting a deposit which underlies an area of several square miles near Shoals, in Martin County. Another deposit has been located in southwestern Owen County but has not been developed. The Indiana Geological Survey is currently drilling in Greene County and is considering further exploratory work in Perry end Dubois Counties.

Jan 1, 1965

The dissolution kinetics of cobalt in iodine/iodide solutions was investigated using a rotating disc technique. Variables studied here included temperature, rotating speed, concentration of lixiviants, and pH of the solution. The overall dissolution reaction was found to be limited by mass transfer of tri-iodide through the diffusion boundary layer with Arrhenius activation energy of less than 16.2 kJ/mol (4 kcal/mol) over the temperature range, 2-42°C. The pH of the solution had little effect as long as the pH of the solution was less than 8. However, when the pH of the solution became greater than 8, the dissolution rate decreased dramatically due to passivation. The rate of dissolution was in good agreement with the dissolution model developed by the authors earlier.

Jan 1, 1994

By J. Carr

Ring gear and pinions used as the final drive on large metallurgical grinding mills are expected to transmit their rated horsepower reliably for long periods of time. Duty is 24 hrs./ day. Life expectancy of such gear sets is of the order of 20 years; that is, each gear and pinion flank is expected to resist failure by pitting for 10 years. This means that for a dual pinion gear set having a ratio of 18.42:1.0 and a mill speed of 10 RPM, every gear tooth will see 105.12 x 106 surface contact stress cycles and every pinion tooth will see 968.15 x 106 surface contact stress cycles in a 10 year period. The allowable surface contact stress on the gear and pinion is determined by the material hardnesses. The rule being the higher the hardness, the higher the allowable surface contact stress may be.

Jan 1, 1985

By Fiona M. Doyle, Christopher R. Lubeck, Michael C. Chin

The fundamentals behind a novel approach for creating inorganic/polymer hybrids are described. The binding of +2 charged ions, specifically Cue-and Cat+, to ionic functional groups is explored through UV-Vis spectroscopy and zeta potential measurements. The novel approach uses an electric field to drive ions into a functionalized polymeric matrix, thereby inducing the precipitation of calcium phosphate species. Scanning electron microscopy images of the resulting composite illustrate the results of these precipitations with two distinct morphologies observed.

Jan 1, 2003

Sedimentation is used to clarify process effluents or to thicken process slurries. The sedimentation cycle of a suspension is presented as a settling curve. This curve is simply a plot of the height of the interface between the settled suspension and clear liquor versus time. Figure 1 shows a series of graduate cylinders which contain a suspension at various stages in its settling cycle. Cylinder 1 shows the suspension completely mixed at time zero. After a brief period of time (see cylinder 2), the suspension is observed to settle from its initial height Ho to height H1, leaving behind a volume of clear (or turbid) liquor, called the supernatant. The interface between the supernatant and suspension is termed the mud line. It is also possible to distinguish at the bottom of the cylinder a layer of sludge representing solids which have settled from the suspension. The interface between it and the suspension is called the sludge line. The sludge line moves upward in the cylinder.

Jan 1, 1992

By Hugo E. Camargo, Amanda S. Azman, Brian Kim

Repeated noise exposure and occupational hearing loss are common health problems across industries and especially within the mining industry. Large mechanized processes, blasting, grinding, drilling, and work that is often in close quarters put many miners at an increased risk of noise overexposure. In stone, sand, and gravel mining, noise is generated from a variety of sources, depending on the type of ore being mined as well as the final consumer product provided by that mine. Depending on the source of noise generation, different strategies to reduce and avoid that noise should be implemented. The National Institute for Occupational Safety and Health (NIOSH) has evaluated the noise profile at three operational surface stone, sand, and gravel mines. A-weighted sound level meter data as well as phase array beamforming data were collected throughout the mines in areas with high noise exposure or high personnel foot or vehicle traffic. Sound level meter data collected on a grid pattern was used to develop sound profiles of the working areas. These sound contour maps as well as phase array beamforming plots were provided to the mines as well as guidance to modify work areas or personnel traffic to reduce noise exposure.

Jan 6, 2022

By Mohammed Laraba, Rodrigo Alvarez Garcia, Juan Maria Menendez-Aguado, Roula Abdelmalek

The aim of this research is the study of the WHIMS parameters on the improving process of a local (DD: Djebel Debbagh, East of Algeria) kaolin. The obtained results of performed XRF, SEM, and XRD characterization showed that this local material is an alumino-silicate containing kaolinite and halloysite with MnO and Fe2O3 impurities (respectively 39.30% and 34.67% alumina and 38.18% and 39.70% silica in both samples (DD2 and DD3). After homogenization, crushing, and milling, a multiparameters factorial experimentation (grain sizes, intensity, and dimension of matrix balls) showed that WHIMS is an effective process to improve the quality of this kaolin, mainly: removing their impurities. Dimensions of matrix balls (Db) = 2 cm, intensity of the applied magnetic field (I) = 1.5 T, and grain sizes (Dp) = > 100 < 250 μm) are the optimal values to reach 91.06% for manganese and 93.45% for iron as removing yield. The statistical analysis of these results sorted the investigation parameters and showed that Db has the highest and most significant influence on the recovery of iron and manganese particles. The magnetic field intensity (I) has a less important influence while the grain size has an average influence (positive on the iron recovery but a negative one on the recovery of manganese).

Jun 11, 2022

By Verya Nasria, William Bent, William Hogan

"The South Hartford Conveyance and Storage Tunnel (SHCST) project is a significant component of the Hartford Metropolitan District’s (MDC) long-term control plan (LTCP), which is overseen by the Connecticut Department of Energy and Environmental Protection (CTDEEP). This project will address a portion of the MDC’s Clean Water Project (CWP), which will reduce combined sewer overflows (CSOs), eliminate sanitary sewer overflows (SSOs), and reduce nitrogen released into the Connecticut River. The purpose of the SHCST project is to eliminate West Hartford and Newington SSOs, eliminate Franklin area CSOs discharging to Wethersfield Cove and minimize CSO discharges to the South Branch Park River. The locations of each overflow are shown in Fig. 1. In 2010, the district prepared a preliminary design report (PDR) for the SHCST project, which included relief of the Folly Brook trunk sewer and proposed to keep the tunnel boring machine (TBM) retrieval shaft within the city limits of Hartford. Figure 1 shows the 2010 PDR recommended tunnel route. Subsequent to the PDR, the objectives of the SHCST have slightly shifted. In accordance with ongoing revisions to the LTCP, relief of the Folly Brook Trunk Sewer is no longer necessary. Additionally, the MDC has decided to perform less sewer separation in the Franklin Avenue drainage area. To replace the sewer separation, new relief points are proposed within the Franklin area and will be diverted to the SHCST. Figure 1 also shows the current recommended tunnel route (Alignment F). During 2012, the MDC conducted an evaluation of the potential of connecting the proposed North Tunnel (originally proposed as an independent tunnel with its own pump station) into the South Hartford Conveyance and Storage Tunnel. This evaluation concluded that the two proposed tunnels could reasonably be connected together and operated as a single tunnel system utilizing the tunnel pump station at the eastern terminus of the South Hartford Tunnel (Fig. 2). It also was concluded that this alternative was less costly than two independent tunnel systems."

Jan 1, 2014

By Ralph C. Flow

In Cleveland County, North Carolina, one and one-half miles south of Kings Mountain, Foote Mineral Company operates an open pit for the production of spodumene, feldspar, mica, and commercial stone. Spodumene concentrate is sent to Footers Sunbright, Virginia plant and to other customers. Exton, Pennsylvania and New Johnsonville, Tennessee plants produce lithium compounds sold to the oil industry for multipurpose lithium-base greases, to the metal industry as welding flux, to the air conditioning market, and to the glass industry. Ceramic grade spodumene, feldspar, and mica concentrates go to other processing companies from the Kings Mountain plant. Waste amphibolite is delivered to a neighboring quarry operation.

Jan 1, 1962

By Rodolfo V. de la Cruz

This paper describes the development of a modified Goodman Jack method for determining the mechanical properties of rock masses in situ. The modified method consists of the basic borehole loading device and a friction-strain-gauge measuring module. The friction gauges, located in the central portion of the jack, are impressed on opposite quadrants of the borehole walls and the remaining quadrants are loaded by the borehole jack with a uniaxial self-equilibrating pair of forces. The tangential strains generated at the borehole walls are thus measured concurrently with the loading. For ideal elastic materials, the tangential stresses at any point on the borehole walls due to jack loading can be obtained from closed-form analytical solutions utilizing the complex variable method. Complete stress-strain curves for the rock material can then be directly obtained from the tangential strain measurements and the calculated tangential stresses at those points. The continuous data are considerably more significant and reliable than averaged or point data obtainable by other current in situ measuring techniques. Moreover, the advantages inherent to the original Goodman Jack method are also obtainable in the modified method. The suitability of the new method was demonstrated by carrying out a number of laboratory measurements in large specimens of reinforced concrete, aluminum and granite blocks. The results of actual field measurements carried out in sandstone and granite quarries were found comparable with those obtained in the laboratory.

Jan 1, 1976

By Edward J. Budill

One of the most dramatic innovations in the materials handling industry has been the development of stacker cranes and automated material handling systems. The stacker crane with its many capabilities and the development of reliable industrial automation controls have combined to produce dramatic achievements in an area once characterized by inefficiency lack of management attention, and capital investment. In many areas of application however, stacker cranes and high rise storage systems have been designed and installed with insufficient thought given to their integration into the overall operations of the plant or distribution facility. This paper will look at some new and interesting breakthroughs in the integration of stacker cranes and high rise storage systems into the total manufacturing plant system. In this paper we will refer to both bridge type stacker cranes and aisle stackers. The bridge type stacker crane was developed first and was initially developed with forks or other handling devices hoisted up and down a rigid or telescopic mast. This mast system was suspended from a trolley mounted on an overhead crane bridge. Today, the primary application of the bridge type stacker is in warehousing systems for handling basic metal products such as coils, bars, sheets and plates. There is no question that the bridge type stacker has achieved notable results in storage and handling of these commodities. However, a new area for stacker crane application has been developing which in many cases over-shadows the accomplishments in the storage area. This is the application of the bridge stacker as an integral part of the manufacturing processes, or in other terms the production applications of stacker cranes. The stacker crane has a number of attributes which makes these applications very important. First, the crane bridge provides the stable platform for the mounting of machinery which can accommodate the hoisting and lateral movement of large capacity loads. Today stacker cranes are being built with capacities of up to 30 - 40 tons. The bridge cranes can easily accomplish accommodation Of these large tonnages. Secondly, the mast system provides a stable platform for the mounting of a wide variety of manipulating devices which can be used for the placement of material into manufacturing processes, the extraction of this material from these processes, and movement to other points in the process area. These attributes combined with excellent operator control and safety have led to development of the stacker crane as a production tool.

Jan 1, 1973

By Matthew Wilcock, Kenichi Soga, Peter Wright

"This paper discusses how an existing grey cast iron segmental tunnel lining responds to construction of a new SCL tunnel transversely beneath with zero clearance; how the damage assessment for the existing tunnel was conducted for impact of longitudinal movement; how the tunnel is subsequently instrumented to observe both movement and stress manifestation at its longitudinal connections and how the results from the instruments compare with the prediction. An assessment of neutral axis of the tunnel in longitudinal flexure is also explored using interpolated horizontal displacement data from a conventional monitoring system. INTRODUCTION The Royal Mail Tunnel (RMT) (formely Post Office Tunnel or ‘Mailrail’) was constructed using semi-mechanised deep level construction techniques from 1914 and 1917 (Lee 1938). Commencing full commercial operation in 1926, the system was until 2003; conveying parcels the 6.5 miles between seven sorting offices in the center of London, and linking the system with main line rail stations, Paddington and Liverpool Street (The British Postal Museum & Archive 2013). A single tunnel of 2.74m internal diameter facilitated a bi-directional twin narrow-gauge (~611mm gauge) railway road system for electric driverless operation. The tunnel lining is segmental grey cast iron (grade 10) made up of six flanged segments and a smaller flanged key segment; constructed into a ring of width 508mm The external diameter of the tunnel is 2.971m. For further details of the tunnel lining and material properties are outlined by (Devriendt & Alhaddad 2014).London Underground Bond Street Station is a major station of the London Underground system in the very center of London; in its vicinity, the RMT runs west-east perpendicularly above the north south Jubilee Line tunnels. Historic survey record of the Jubilee Line’s (the then Fleet Line) construction in 1974 and its impact on the RMT case is documented in (Crossrail 1993): it is one of only a hand full of case-studies frequently cited when assessing the impact of new construction scenarios of this type; not least including the assessment of the same tunnel, at the same site some 40 years later, and the subject material for this paper: It noted significant vertical displacement of ~90mm to the RMT without noticeable serviceability or operational impediment."

Jan 1, 2016

By R. M. Carland, F. F. Aplan

Six natural zeolites were evaluated for their ability to selectively remove heavy metal cations from solution. Ion selectivity was found to be Pb+2>Zn+2>Ni+2 and Cu+2>Co+2 from their respective solutions. The presence of K+, Ca+2 and Mg+2 in the actual waters to be used may seriously interfere with the ion exchange and elution of cations from zeolites. Zeolites were found not to be effective in removing precious metals from their cyanide solutions.

Jan 1, 1995