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By W. H. Ode

Low-temperature distillation tests at 200°, 350°, and 500° C. were made on a subbituminous coal from Boulder County, Colo., and a subbituminous coal from Weld County, Colo., in connection with a survey of carbonizing properties of American coals and investigations of their chemical and physical properties. The coal represented by the sample from Weld County was reported to give off combustible volatile matter at unusually low temperatures When placed on a fuel bed. The yields of tar and oil and the composition of the gas from this coal, as obtained in the distillation tests, did not confirm this report. These yields and the gas composition of the Weld. County coal differed but little from those obtained from the coal from Boulder County. Both coals yielded tar and gas in amounts considered to be normal for coals of their rank.

Jan 1, 1937

By G. M. Schwartz, J. N. Gundersen

Utilization of magnetite-bearing taconite from the great Mesabi range of Minnesota is fast becoming a major industry in the state. The planning and early development stages of taconite processing projects have been de-scribed1-3 and an excellent discussion has appeared recently4 concerning the current mining, crushing, concentrating, and pelletizing techniques of the Reserve Mining Co., whose operations lie entirely within the Eastern Mesabi district. The present paper will deal only with some of the geological aspects of taconite utilization in the district, with emphasis placed upon some of the common mineralogical and textural features of the tacon-ites currently being mined or stripped and how these factors generally affect the potential recovery of the iron from the metamorphosed Biwabik iron-formation. The generalized geologic setting of the Eastern Mesabi district is presented in Fig. 1. The small circles on the geologic map, adapted from Grout and Broderick,3 mark the location of drill holes that were available for inspection during this study through the courtesy of Reserve Mining and Erie Mining Cos. The cores from these holes were divided into stratigraphic units and examined for their mineral content. Typical mineral associations and grain fabrics were also determined from hundreds of thin and polished sections. Available metallurgical tests made it possible to determine the probable response of a given variety of taconite to magnetic concentration. The longitudinal section of Fig. 1, projected along the strike of the iron formation, presents the simple stratigraphy of the area. It also shows the uniformly thick nature of the iron formation members in the district as well as a somewhat abrupt thickening of the formation to the west of the probable fault. The stratigraphy of these precambrian rocks has been described5-' elsewhere and need only be briefly reviewed. Historically, the oldest rocks unit, the Giants Range granite (Algoman) was covered by the Animikie group of sediments (Middle Huronian?), consisting of the Pokegama, Biwabik, and Virginia formations. Outcrops of the Pokegama quartzite are locally distributed along the northern limit of the Biwabik iron formation, but they are too limited to depict on the geologic map of Fig. 1. The effects of the intrusion of several small diabase sills within the Virginia and Biwabik formations are obscure because all of these rocks have been subsequently highly metamorphosed, mainly by the Duluth gabbro. The emplacement of the transgressing Duluth gabbro (Middle Keweenawan) and that of numerous peg-matitic veins in the iron formation8 has resulted in extensive contact and metasomatic metamorphism which has locally reconstituted the previously existing minerals of the Biwabik formation, in large part quartz and magnetite, into a wide variety of silicate mineral assemblages9 that have a profound effect upon the re coverability of the remaining magnetite. The entire region has subsequently been eroded and largely buried beneath Pleistocene glacial deposits. Structurally, the strike of the gently dipping Animikie group generally parallels the elongate outcrop pattern of the Biwabik iron formation on the map of Fig. 1. The Animikie group most commonly dips from 5" to 15" to the south-southeast. In this area, the Duluth gabbro pluton is somewhat sill-like, dipping about 30" to the southeast. Projecting these present structures upward, it seems probable that the gabbro once extended over the underlying Animikie group in the Eastern Mesabi district. SELECTION AND PRESENTATION OF DATA Because of the locally intense metamorphic activity in the district, mineralogical variations within the magnetite-bearing taconites are commonly abrupt, both vertically and laterally. Consequently it is difficult to select a single hole or small group of holes whose cores will be entirely representative of all of the district. Two holes have been selected, however, that in a general way represent mineralogical and textural variations that are likely to be encountered in both the eastern and western parts of the district. These recently drilled holes were chosen for discussion because it was possible to log the core and then to place the sample intervals at stratigraphic boundaries prior to preparation of the core for magnetic tube tests.

Jan 1, 1961

By A. C. Fieldner

"INTRODUCTION In a previous report3 prepared for the American Gas Association, the influence of washing coal on coke properties and on gas and by-product yields was discussed on the basis of answers to questionnaires sent to coke-oven superintendents and a review of the literature on the subject. This review indicated that the elimination of free impurities by cleaning coal improved coke quality by (a) reducing ash and sulphur, (b) decreasing clinker trouble in burning the coke, (c) diminishing cross fractures in the coke, resulting in greater resistance to breakage on handling, and less small coke and breeze, and (d) greater uniformity in chemical composition and physical properties of coke. Washing also reduced the sulphur in coke and gas and increased the yield of gas and by-products per ton of dry coal charged.This paper is supplementary to the previous report and presents some experimental data obtained with Pittsburgh bed coal from Pennsylvania and Mary Lee bed coal from Alabama.ACKNOWLEDGMENTSGrateful acknowledgment is made to F. J. Pfluke, of the Rochester Gas and Electric Cc., of Rochester, N. Y., for the plant test data on screened lump and washed coal; and to Ray W. Arms, Manager of the Coal Cleaning Department, of Roberts & Schaefer Co., of Chicago, for the data on effect of air cleaning."

May 1, 1931

By EDWARD B. DURHAH

The illustration Fig. 12, of the paper of Edward B. Durham, "Electrolytic Refining at the U. S. Mint, San Francisco, Cal.," printed in Bulletin No. 58, October, 1911, p. 830, contained an error. The corrected diagram is printed below.

Nov 1, 1911

By P. W. King

The performance of the versatile McNally Wedag horizontal vibratory centrifuge for dewatering ultra fine 0.5 x 0.15 mm (28 x 100 mesh) material has proven to be success¬ful and the results presented herein will examine its capabilities in terms of capacity, solids capture, product moisture, effluent solids, and size analysis. Centrifugal dewatering of fine refuse has proven t to be another application for which this unit has performed exceptionally well.

Jan 1, 1985

By H. R. Wheeler

CREATION of a "committee on promotion of student interest in coal mining" has an encouraging implication for the coal industry. It is indicative that mining men, both in the field and in the educational centers, realize that the problems of the industry require the best talent available. Young men are being invited into coal on the premise that it needs them, that it offers opportunity for creative work and the realization of their objectives. In initiating a movement which purports to meet the objectives of any young man who spends four or five years of his life in college, the industry does so with a full realization of its obligations.

Jan 1, 1940

By Andrew Higgins, Jamey Rosen

This presentation will demonstrate some recent advancements in the applications of Project Information Systems (PIMS) technology to seepage barrier walls in the context of evolving Owner Specifications. The use of geospatial technology in particular is used to track, visualize, and analyze data from a variety of sources and serve those data to contractors and owners via dashboards and as-built drawings. Data describing the geometry of construction elements (including diaphragm panels, secant piles, and jet grout columns) is of particular importance on these projects, and this presentation will include case studies in the United States of how these data are used to determine if a barrier wall is constructed as designed and if it meets the owner specifications with respect to tolerance (i.e., if each element is sufficiently close to vertical) and overlap (i.e., do adjacent elements overlap sufficiently to prevent leakage).

May 1, 2022

By John A. Putnam, Morrough P. O’Brien

DATA on the physical and thermodynamic properties of hydrocarbons have been made available in recent years but the formal method of applying these data to flow in porous media appears not to have been fully developed. By making usual thermodynamic assumptions and employing existing data on permeability to two-phase flow, Darcy's law may be applied to obtain the flow characteristics for representative combinations of flowing medium and geometry. The numerical examples presented herein are based on hydrocarbons for which complete physical and thermodynamic data are available under equilibrium conditions. INTRODUCTION Thermodynamic data are obtained in the laboratory under equilibrium conditions and their application requires the assumption that equilibrium also exists during flow. This assumption is at least usual in engineering analyses, though not easily justified in many instances, and will be followed here. In regard to hydrocarbons, laboratory experience in determining the pressure-volume-temperature relationships indicates that gas-liquid mixtures must often be stirred vigorously for periods of 15 to 20 min. before reaching equilibrium. On the other hand, boiling and condensation are known to occur on solid surfaces and the large surface exposed to the flowing substance by a porous medium may bring about rapid approach to equilibrium. For the purpose of providing at least a guide to experimentation and a standard for later comparison with experimental results, it will be assumed that the phases present in cross sections perpendicular to the direction of flow are in thermodynamic equilibrium. Another assumption usually made in the solution of problems of flow in porous media is that the fluid remains at a constant temperature; i.e., isothermal flow. This assumption is arrived at by considering the porous medium and surroundings to be an infinite heat source and the rate of heat flow to be infinite at a boiling front. Its validity depends in large measure upon the character of flow, the number of components, and the physical and thermodynamic properties of the fluid. However, the assumption of isothermal flow represents a limiting case. The other limit can be represented by the assumption that the fluid is thermally isolated; i.e., irreversible adiabatic. The thermodynamic process characterizing the actual flow of a given fluid system probably lies somewhere between these two limiting cases and might be thought of as a flow system in which the confining walls are maintained at a constant temperature. For isothermal flow the solid material of the porous media is considered as the infinite heat source capable, without loss in temperature, of giving up heat to the fluid as the latter tends to cool by expansion. For the thermally isolated system, the solid material is considered to give up no heat to the fluid. In the intermediate case the impervious walls confining the porous media are at constant temperature from which heat is transferred along various paths, solid and fluid, throughout the porous media. It would appear that an actual petroleum-

Jan 1, 1941

Ridgeway Gold Mine (Ridgeway) has a clear mission to maximise its cash flows in order to deliver shareholder value and is developing strategies to achieve this. Business process management using leading measures is core to this approach. Leading measures indicate potential outcomes ahead of time, allowing time to adapt and improve. Ridgeway is making strategy a central organisational agenda, creating a focus to æput first things firstÆ by controlling æleadingÆ activities and mobilising employees to act. Feedback using specific, leading measures gives employees the opportunity to proactively adapt their behaviour in order to deliver internal business outcomes that generate cash flows and shareholder value. This paper will outline RidgewayÆs business approach to track and control processes from resource to revenue, with a focus on delivering cash flows and shareholder value. Ridgeway is implementing a Balanced Scorecard approach (Kaplan and Norton, 1996). A total business focus is taken and leading measures are identified. Specific measures are used to score our success from the perspectives of learning and growth, internal business processes, customer and stakeholders, and finance. These measures and improvement plans are targeted at strategies to maintain our ælicence to operateÆ with our community stakeholders, produce accurate plans and forecasts, improve our operational effectiveness and grow our business.

Jan 1, 2002

By A. H. Swart

Unplanned stope panel collapses occur on most near-surface and shallow mines in South Africa. Although these incidents often occur during blasting, they pose a major threat to the safety of underground workers and the economic extraction of orebodies. Most stope panel collapses occur due to excessive panel lengths (resulting in excessive stope spans) that are not designed according to a systematic design procedure or methodology. Instead, panel lengths are often dictated by the equipment in use and by previous experience under similar conditions. Hence, a rock engineering design methodology for the design of stable stope panels between pillars is of vital importance for optimum safety and production in shallow mining operations. Using the proposed design methodology described in this paper, rock mechanics practitioners and mine planners should be able to identify and quantify the critical factors influencing the stability of stope panels. The critical factors should then be used as input to the design of stable stope panels that will provide the necessary safe environment for underground personnel working in stopes. The proposed design methodology is an iterative process, which includes aspects such as rock mass characterization, estimation of rock mass properties, identification of potential failure modes, consideration of appropriate stability analyses and other elements of the rock engineering design process. This process continues after implementation. During monitoring, new data should be included in the database and the design process repeated on a regular basis. Design approaches included in the proposed design methodology include empirical methods such as different rock mass classification methods, analytical methods such as elastic and Voussoir beam analyses, kinematic analyses, probabilistic analyses, and numerical analyses. Keywords: stability, stope panels, design methodology, hardrock mines, shallow mining operations

Jan 1, 2005

By L. Rademeyer, P. Mazzoni, C. Kubank, F. Brown

The Corridor Sands deposits of heavy mineral sands represent the largest known economic resource of titanium dioxide minerals. The West Block of Deposit 1 alone contains Measured and Indicated Mineral Resources of 1.7 billion tonnes containing 4.14 per cent ilmenite, estimated in accordance with the JORC standard, sufficient for at least the first 20 years of mining. Total mineral resources are estimated to be approximately 17 billion tonnes at 5 per cent Total Heavy Minerals (THM). Test work was undertaken on the West Block of Deposit 1 over a period of two years in order to develop the process flow sheet to bankable standards. Geological, mineralogical and metallurgical test work was integrated from a pre-feasibility stage to the full bankable stage. The process flowsheet was developed with the central objective of the production of saleable products, of consistent quality and acceptable to the respective end-markets. The aim of this paper is to describe the way in which the various challenges for the project have been addressed by using integrated geological and mineralogical information, which has resulted in the development of a complete flow sheet. The process confirmed that material within customer specifications could be produced, once various metallurgical parameters were understood. This flow sheet development progressed from laboratory test work through to full field trials at pilot plant scale on large consignments of mineralized material. The flow sheet was developed to such a standard as to be used with confidence for both engineering design and cost estimates, and to determine the recovery factors to be used in financial evaluations. Keywords: Corridor sands, Flow sheet, Pilot plant Titanium dioxide

Jan 1, 2003

Ontario Operaations Mining Garson Stobie Copper Cliff North Copper Cliff South Creighton Mcreedy East Milling Clarabelle Mill Smelting Smelter Matte Processing Anode Casting Refining Copper Cliff Nickel Refinery Port Colborne Cobalt Refinery

May 1, 2007

By John J. Henn

Two lime sinter processes for recovering alumina from clay, the double-leach process and the single-leach process, are evaluated in this Bureau of Mines report. In both processes, clay and limestone are mixed and sintered to form calcium aluminate from which alumina is extracted as sodium aluminate by leaching with a dilute solution of sodium carbonate. The pregnant liquor is desilicated, then carbonated to precipitate alumina trihydrate which is recovered and calcined to a,-alumina. The fixed capital costs for plants producing 1,000 tons per day of alumina are $85 million for the double-leach process and $86 million for the single-leach process based on a Marshall and Stevens chemical equipment index of 240.0. Because plant locations are variable with respect to the proximity of clay and limestone deposits, a nomograph is included to determine operating costs at various delivered costs of clay and limestone. For plants at which the delivered cost of clay containing 30 percent A1203 is $2 per ton and the delivered cost of limestone is $1 per ton, the operating costs are $81.04 and $89.87 per ton of alumina for the double-leach process and single-leach pro-cess, respectively.

Jan 1, 1969

By Christian Bourcier

La méthode d?exploitation traditionnelle de la mine est le chantier chambre-magasin. Cependant, lors de l?exploitation d?un chantier, nous avons été confrontés à un problème de soutirage. Le minerai abattu est resté accroché à l?intérieur du chantier ce qui nous obligea à soutirer environ 200 wagons, représentant 700 tonnes. Suite à l?ampleur de la situation, nous avons décidé de finir l?exploitation du chantier par la méthode sous-niveau long trou retraité. Cette première expérience de récupération de piliers ayant été réalisée avec succès, nous avons décidé de continuer avec deux autres récupérations de piliers afin de pouvoir augmenter notre expertise autant au niveau technique qu?au niveau économique.

Oct 1, 2001

By Ian M. Loomis, Keith G. Wallace

The Waste Isolation Pilot Plant (WIPP) is a U.S. Department of Energy research and development facility designed to demonstrate the permanent, safe disposal of U.S. defense-generated transuranic waste. The waste storage horizon is 655 m (2150 ft) below surface in bedded salt. To date the WIPP project has not emplaced any waste. There are three intake shafts used to supply air to the underground. All air is exhausted though a single return shaft. The total design airflow during normal operations is 200 m3/s (424,000 cfm). The ventilation system is designed to provide separate air splits to construction, experimental, and storage activities. Separation is achieved by isolating the storage circuit from the construction or experimental circuits with bulkheads. Any air leakage must be towards the storage area of the facility. Field studies have shown that the pressure differential necessary to maintain the correct leakage direction is susceptible to the effects of natural ventilation; therefore, extensive studies and analyses have been conducted to quantity the natural ventilation effects on the WIPP underground airflow system. A component of this work is a monitoring system designed to measure the air properties necessary for calculation of the natural ventilation pressure (NVP). This monitoring system consists of measuring dry bulb temperature, relative humidity, and barometric pressure at strategic locations on surface and underground. The psychrometric parameters of the air are measured every fifteen minutes. From these data, trends can be determined showing the impact of NVP on the ventilation system during diurnal variations in surface climate. Both summer and winter conditions have been studied. To the author's knowledge this is the first reported instance of automatic and continuous production of time and temperature variant NVPs. This paper describes the results of the initial monitoring study. INTRODUCTION The ventilation system at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico, is designed to perform two distinct functions. First, it supports normal mine ventilation requirements complying with all state and federal mine regulations. Second, the system is designed to prevent an uncontrolled release of radioactive contaminants from the storage and transportation areas of the facility. Although a nuclear radiation release in the facility is considered unlikely, many special features are implemented in the ventilation system to prevent the possible spread of contamination. The facility is constructed with the waste transportation and storage areas separated from the mining and non-radioactive experimental areas. The ventilation system is designed such that air leakage is from the mining and experimental areas to the storage areas. Furthermore, radiation detectors are located throughout the storage and waste transportation areas underground and an exhaust filtration building is installed on surface to prevent the possible release of radiation to the environment. For over two years the underground ventilation system has been rigorously tested and balanced. It was during this period that the adverse effects of NVP were noticed and subsequently quantified. From extensive field studies and computer models, several mitigating features were designed and constructed and special operational procedures were implemented to control the impacts of NVP. To quantify more accurately the NVP at the WIPP, a continuous monitoring system was installed. This monitoring system consists of measuring dry bulb temperature, relative humidity, and barometric pressure every fifteen minutes at strategic locations on surface and underground. From this psychrometric data, the NVP is calculated. Fan operating pressures and flows and strategic differential pressures are recorded from the site Continuous Monitoring System (CMS). The monitoring system provides a means of evaluating how the ventilation system behaves in regard to climatic conditions and to judge the efficacy of the mitigating features and operational procedures. To the author's knowledge, continuous calculation of NVP as a function of time and surface temperature has not been previously reported. Overview of the Waste Isolation Pilot Plant The U.S. Department of Energy determined that the plastic nature of bedded salt may provide the best solution to isolate transuranic (TRU) waste from the biosphere. Initial evaluations at the WIPP site began in 1974. In 1979, the United States Congress enacted Public Law 96-164 for the construction and development of the WIPP project. The mission of the WIPP is to demonstrate the safe, long-term disposal of TRU waste generated by the national defense programs of the United States. TRU waste is classified as a low to medium level waste. The waste is stored in drums and does not produce significant heat (not greater than 1 W per drum). The WIPP site is located approximately 47 km (29 miles) east of Carlsbad, New Mexico in the Chihuahuan Desert. The repository is located in the 630 m (2000 ft) thick Salado Formation. This Permian Basin salt deposit is about 225 million years old and appears to have been minimally disturbed by earthquake, faulting, and ground water activity since it was deposited. The underground facility is 660 m

Jan 1, 1993

By M. S. Klima

Tests were conducted to investigate the potential for recovering anthracite from preparation plant tailings. Samples were collected from tailings streams or slurry ponds of several anthracite cleaning plants. A washability analysis was conducted on each sample. The use of gravity-and surface-based cleaning processes for treating the 28x200 mesh tailings material was examined. Simulations were performed for various cyclone staging arrangements using published partition data for both water-only and dense-medium cyclones. Froth flotation testing was done on both precleaned anthracite and tailings material. Grade-yield curves were determined for various conditions.

Jan 1, 1995

By J. H. Zietsman, S. Maharajh, J. Muller

In the chlorination process for TiO2 pigment production, blends of titania feedstocks such as ilmenite, synthetic rutile (SR), natural rutile, upgraded slag, and chloride-grade slag are reacted with coke and chlorine at a temperature of around 1000°C to form TiCl4, which is the main product, and other waste metal chlorides. TiCl4 is the main feed material for the TiO2 pigment-making process. Feeding different titania materials to the chlorinator affects the amounts of coke and chlorine required for the process, the amount of waste generated, waste disposal costs, the amount of TiCl4 produced, and bed build-up rates. These factors influence the value of the feedstock. Generally, a higher TiO2 feedstock is more valued since less waste is generated and less reagents are consumed. To quantify the impact of different feedstocks on the chlorinator, a techno-economic model was developed to describe the chlorination process and estimate process variables at steady state. This paper describes the development of the model and studies in which the model has been used to quantify the effects of using different feedstocks.

Jan 1, 2014

By Augusto V. Ramírez

"El presente texto revisa algunos aspectos de la historia minera en los Andes Centrales -particularmente la negociación minera de Aguas Calientes, ubicada en Casapalca. La mina data de 1917, cuyo propietario fue Ricardo Bentín Sánchez. Asimismo, se revisa los antiguos procesos de extración y ventilación, la oficina de concentración, enfermedad y accidentes de trabajo y los aspectos sociales de la vida en Aguas Calientes. "

Feb 1, 2017

By F. W. Mueller

It seems to be a matter of general understnading that title extraction or use of ground water may not be used as the basis of a depletion deduction under the United States Revenue Code And indeed, I have been unable to find any precedent upon which to base such a deduction. It is for this reason that the Shurbet case, which is the subject of my discussion and is now before the Court, may well become a precedent as authority for the allowance or disallowance of a depletion deduction for income purposes. It is well known that the law recognized that capital is consumed in the process of extracting minerals, oil and has, other natural deposits, and timber (underscoring supplied). This exhaustion, or depletion, is likened to the using up of raw materials in manufacturing. The law, therefore, provides a deduction for depletion which is intended as compensation for the exhaustion of assets consumed in the production of income through severance of minerals, oil and gas, other natural deposits, and timber.

Jan 1, 1962

By Gandhi

Piled raft foundation under uniformly distributed vertical loads has been analyzed using Finite Element Method. The soil is considered to be linear elastic, isotropic, homogeneous. The raft,pile and the soil have been idealized with eight noded brick elements. Parametric study have been carried out varying pile length, soil modulus, raft thickness, and pile spacing. Design charts have been produced to achieve 50% load sharing between pile and raft for optimum design. Data available in literature is compared with the design chart results and found satisfactory.

Jan 1, 1996