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By Walter Kawa

Bureau of Mines research on the hydrogenation of coal has been concerned with developing processes that could be used to supplement the Nation's petroleum and natural gas resources. Motor fuel was produced in a subsidized coal hydrogenation industry in Europe prior to 1945, but the process used is still not economical and other methods of producing liquid and gaseous fuels from coal are being investigated. As an aid to the planning of coal hydrogenation research, a literature survey was made of processes or methods of hydrogenating coal that differ from the subsidized or conventional process. This report contains a bibliography of unconventional methods of hydrogenating coal and a brief discussion of the economics of the conventional method. A general discussion of unconventional methods is included, and the advantages and disadvantages are pointed out where possible. The survey supplements a previous Bureau of Mines survey3 and a comprehensive review published in 1930.4

Jan 1, 1964

By A. K. Majumder

In an effort to test the extent to which fundamental fluid mechanics can provide a prediction of particle separation, a study on a simple parallel-sided sluice has been carried out using glass bead and ilmenite mixtures at various particle concentrations and flow rates. Great care was taken to devise a flow splitter at the end of the sluice that permitted accurate measurement of the fluid flow profile and collection of slurry samples, allowing evaluation of the particle species concentration profiles. The actual particle separation taking place was compared to predictions made by first describing the fluid flow by a modified ?law of the wall? model. The hydrostatic pressure variation in the flow was taken into account and the eddy viscosity was calculated from a mixing length expression incorporating Van Driest?s damping function. Using an average density and viscosity provides an explicit expression for the velocity gradient that can be numerically integrated for the flow profile. The particle concentration distributions were then modelled with Hunt?s sediment transport model assuming the particle eddy diffusion coefficient to be the same as that for the water. Hindered settling velocities of the particles were calculated using Brauer and Thiele?s formula, which takes the particle size and density distributions and solids volumetric concentration into account. The resulting predictions of particle separation are shown to be a strong function of the settling velocities of the particles used. Keywords: flowing film concentrators, fluid velocity

Sep 1, 2012

By Alan Bauer

New developments in drilling, blasting and explosives in both open-pit and underground mining operations are discussed, as well as novel surface blasting techniques such as are used in tar sand mining.

Jan 1, 1978

By Abhilash

Different methods of utilizing refractory bauxite and disposing red mud are practiced throughout the world, but none of them are known to be environmentally innocuous due to the complexity and /or high cost, and none has been found to be feasible on an industrial scale. Under these conditions, the use of bioleaching process seems promising. The present study emphasizes on the isolation of native extremophiles from the source Indian bauxite and red mud, with their detailed cellular and physio-chemical, and biochemical characterization. These organisms were tested for their ability to thrive in physically or geochemically extreme conditions. The gram positive capsule rich mesophiles and thermophiles were tested for removal of gangue minerals from the bauxite and red mud samples. Keywords: refractory bauxite, red mud, extremophiles, bio-beneficiation, gangue

Sep 1, 2012

By M. J. Sheridan

"INTRODUCTION In December 1942, the-Bureau of Mines reported favorably on a proposal to grant Government assistance-in constructing an access road (consisting principally of a timber-pile bridge across the Rio Grande at Hot Springs, N. Mex.) to the property under lease to the United States Fluorspar Co. At that time the property was being developed actively, and there appeared to be no immediate-need for exploratory or metallurgical assistance by the Bureau of Mines.Because milling facilities were inadequate; the access-read project was eventually disapproved, but prior to disapproval the company had discontinued operations. In June 1943, exploration was resumed by the Humphreys Gold Corporation of Denver, which had subleased the property. Difficulty of access continued to interfere with exploratory progress. In July 1945, at the request of the lessee, the Bureau of Mines directed sampling, using company employees.At the completion of this sampling program, the Bureau of Mines concluded that the property was potentially a important source of fluorite but that further development for production appeared to depend largely on the establishment, by exploration, of adequate reserves. Because of the relatively easy position-of metallurgical-grade concentrate and ores, it also was deemed advisable to investigate the possibility of producing acid-grade concentrate from the ore, for which a demand was becoming evident. Accordingly, a program of trenching, diamond drilling, and metallurgical testing was undertaken by the Bureau. The results of its investigation are reported herein."

Feb 1, 1947

By Robert Hochscheid

A patent issued to J.N.J. Leeman (1957) described the change in performance that takes place when a cyclone is installed in the horizontal position rather than the vertical position. Although this patent was directed more toward improvements that could be realized in the heavy medium cleaning of coal, it contained specific references to reducing the quantity of fine solids that would report in the underflow, and an example for fine sand classification is also included. The three cyclone installations for which data is given in this paper demonstrate that horizontal mounting of large cyclones can improve classification efficiency, eliminate some operational difficulties, and reduce cyclone maintenance requirements in closed circuit grinding installations. Cyclone Experience at Serrana S.A. Each of four grinding circuits at the Serrana S.A. de Mineracao Apatite flotation plant in Brazil have a 2.7 X 4.6 meter (9 X 15 foot) rod mill and each originally operated in closed circuit with two vertically mounted Model D20B (500m nominal diameter) Krebs Cyclones. New feed size is 25mm. The Apatite is liberated at a relatively coarse 35 to 28 mesh grind, but the 500mm cyclones had to be fed at 66 pct. solids in order to obtain an overflow analyzing 12 pct. coarser than 42 mesh. Because dilution water in the cyclone feed had to be limited, classification was inefficient, and there were other significant circuit difficulties as summarized in a recent article by C. A. Busnardo (1984):

Jan 1, 1985

By S Hawker, M Gibbs, A Craven

Current climate change projections suggest both an increase in the intensity of significant rainfall events and an increase in the variability of rainfall in some regions of Australia. It is necessary for mine site owners and operators to understand the effects that this potential shift in climate may have on their operations. The ability to maintain compliance with discharge regulations and operational security for those sites that rely on surface water run-off harvesting may be negatively impacted if some current climate change projections are realised. Although current regulations require the preparation of water management plans, these are generally developed using historical climate records for the site in question and as such do not give any indication of a siteÆs resilience to the influences of climate change.This study compares design and operational considerations for a case study mine site using historical rainfall records and modified records representing climate change projections. The future climate models are invariably broad scale and are limited in their capacity to be downscaled to a reasonable resolution for developing a site water balance. Instead the local historical data set has been modified to concentrate precipitation to peak periods and propagated through the model. The study looks at the siteÆs response to the potential changes in climate.It is shown that if current climate change projections are realised, this will have a significant effect on both the necessary size of designed surface water infrastructure and operational considerations on-site. A discussion is presented on the potential risks that climate change presents to mine sites and the range of options that could be considered to mitigate these risks. Depending on a number of factors, including location and risk profile of the owner/operator, resilience to climate change can be addressed as either a capital or operational expenditure (CAPEX/OPEX).CITATION:Craven, A, Hawker, S and Gibbs, M, 2013. Site water balance response to variable climatic conditions, in Proceedings Water in Mining 2013 , pp 211-216 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By K. B. Rojiani

Surface mining activities disturb large tracts of land resulting in the potential for greatly increased downstream sediment loads. The Surface Mining Control and Reclamation Act of 1977 places increased emphasis on the protection of the environment from the adverse effects of surface mining operations. Surface mining activities must be planned to minimize disturbance to the hydrologic balance, erosion and sediment contributions to receiving streams. Sediment ponds must provide a sediment storage volume equal to the accumulated sediment volume from the drainage area as determined by the Universal Soil Loss Equation (USLE) or other empirical methods established by the regulatory authority. It has thus become extremely important for the mining industry to secure more accurate estimates of potential erosion losses and sediment yield. Accurate estimates of sediment yield are required for the planning, design and successful operation of sediment control systems such as detention ponds and other alternative control structures and for evaluating the effectiveness of land management practices. The principal soil loss prediction procedure available for use is the LISLE. The USLE procedure is inadequate for use in predicting soil loss from surface mine regions for a number of reasons. These include: 1. The USLE was developed to estimate average average annual loss from agricultural soils. It cannot predict accurately soil loss for specific storm events. In surface mine regions a major portion of the soil loss occurs during the initial six months to one year of active mining. Accurate estimates of soil loss over short periods are thus required for the design of control structures. 2. The slope length and gradient factors used in the USLE were obtained from data or cropland having slopes ranging

Jan 1, 1983

By H G. Poulos

"This paper sets out a simplified approach by which the practical foundation designer can undertake the relevant calculations to satisfy the requirements for deep foundation design in seismic areas. The following matters are dealt with:a. Design issues that should be addressed;b. Pile design for axial loading, including the possible effects of liquefaction;c. Pile design for lateral loading where liquefaction does not occur;d. Pile design for lateral loading where liquefaction does occur;e. Measures to mitigate against liquefaction effects.The paper is a modified version of a paper presented in 2013 to the 19th NZGS GeotechnicalSymposium, Queenstown, New Zealand.1. INTRODUCTIONConsideration of the effects of earthquakes and seismic loadings is an increasingly important aspect of modern foundation design, and most contemporary standards have a mandatory requirement for such consideration. For example, the Australian Piling Code, AS 2159-2009, states that “a pile shall be designed for adequate strength, stiffness and ductility under load combinations including earthquake design actions”. However, the methods by which such considerations can be undertaken are generally not set out in the standards, and many approaches have been utilized, ranging from very simplistic methods to extremely complex computer analyses. Accordingly, there appears to be scope for an approach that is soundly based but which is neither too simplistic nor too complex.Poulos (1989) has suggested that there are three categories of analysis and design, as follows:1. Category 1: empirical methods.2. Category 2: simplified but soundly-based methods.3. Category 3: more comprehensive methods that are soundly-based, and site-specific.The objective of this paper is to set out a systematic but simplified approach which falls into Category 2 above, and by which the foundation designer can undertake the relevant analyses to satisfy the foundation design requirements for seismic regions. Emphasis is placed on methods that do not require “black box” software or which employ complex soil models in which the physical meaning of the parameters is unclear."

Jan 1, 1900

By G Bubner, C Gaughan

Magnetite mineralisation within the South Middleback Range has been known since the early 1930s; however, it was not until 1989 that BHP (then owners of the Middleback Ranges mining leases) drilled 10 700 m of diamond core into what was then known as the Iron Duchess low-grade deposit. In 2002 a review of Iron Resources left in the Middleback Ranges and the identification of downstream processing benefits using magnetite as a primary feed source led to the commencement of an 18 000 m resource drilling program of the high-grade core of the Iron Duchess low-grade orebody (renamed the Iron Magnet deposit). This paper describes the geology, processes and procedures used since drilling recommenced in early 2003. The Iron Magnet deposit is located 53 km southwest of Whyalla in the South Middleback Range, South Australia. It is a Paleoproterozoic stratabound magnetite deposit that lies down-dip and lateral to the Iron Duke hematite deposit, hosted within the Lower Middleback Iron Formation of the Hutchison Group meta-sediments within the Cleve subdomain of the Gawler Craton. Magnetite bearing host units within the Lower Middleback Iron Formation can be divided into a æmixedÆ basal sequence, a lower iron carbonate unit, a middle iron talc unit and an upper iron silica unit, all units grading up sequence and laterally into one another. The magnetite mineralisation is hydrothermal in origin. The strongest consistent mineralisation coincides with the iron carbonate unit, and the hematite orebodies of the Iron Duke are interpreted to represent up-dip supergene enrichment of the same unit. The Iron Magnet occurs within a large-scale parasitic syncline-anticline pair on the west limb of a larger syncline. Major bounding north-south shear zones occur on the east and west sides of the deposit. Cross-cutting west-northwest, northwest, northeast and east-northeast trending faults displace mineralisation. The commencement of drilling in 2003 lead to the migration of geological and geochemical databases, re-logging and re-assaying of all old cores that intersected the deposit, updating of logging codes and procedures, and strict Qa/Qc procedures to ensure the study satisfied JORC standards. External consultants were used for auditing and bench marking. The strong geophysical responses of magnetite and the wealth of close spaced ground magnetic and gravity data already completed over the Middleback Ranges allowed for refining of drill hole targets for the drilling program. It also provided an indirect method for ascertaining magnetite grade and tonnage volumes.

Jan 1, 2005

By J. A. González-Anaya, F. Nava-Alonso, O. Alonso-González, F. Alvarado-Hernandez, A. Uribe-Salas, C. Jimenez-Velasco

"One of the most common hydrometallurgical methods for precious metal extraction is cyanidation. The effluents of this process may contain relatively high concentrations of copper, zinc and iron, which react with free cyanide to form complexes, adversely affecting the efficiency and the economy of the process.This preliminary work studies the use of the solvent extraction technique to remove copper, zinc and iron cyanide complexes from a synthetic solution similar to that of gold mill effluents, in order to allow the recycling of the solution back to the process. For the extraction of these anions (Cu(CN)2 -, Cu(CN)3 2-, Cu(CN)4 3-, Zn(CN)4 2- and Fe(CN)6 3-), trioctyl methyl ammonium chloride (Aliquat 336) was studied as extractant, using nonylphenol as modifier in the organic phase (iso-octane). The experimental results showed that for a synthetic solution containing 450 mg/L total cyanide, 160 mg/L copper, 50 mg/L zinc and 51 mg/L iron, it is possible to extract the 96% of copper, 91% of zinc and 75% of iron when using 0.011 mol/L of Aliquat 336 (organic/aqueous volume ratio (O/A) =1) in the pH range of 9-10."

Jan 1, 2014

By R. J. Mitchell

"A lest apparatus has been developed for obtaining the relations among confining stress, porosity and percolation rate for hydraulic sand backfills. The apparatus can also be used to evaluate internal drainage characteristics and the effects of partial saturation on percolation rates. The test apparatus, test procedures and typical test data are presented in this paper.IntroductionAlthough the standard percolation test has become an accepted method of evaluating the drainage characteristics of hydraulically placed tailings backfill, it is recognized that the test results require considerable interpretation due to the following factors: (I) The results can be markedly influenced by varying sample preparation procedures, which vary the amount of material segregation in the sample . In particular, a thin layer of slimes on the top of a sample can control the flow of water into the sample. Wall edge effects can also affect the test results. (2) The in-place porosity of the backfill is not duplicated in the test sample and empirical formulae must be used to estimate the variation of percolation rate with porosity. (3) Internal drainage characteristics and the percolation rate of partly saturated fill cannot be evaluated in the standard percolation test.In addition to eliminating these problems, the compression percolation test apparatus also provides additional data on the mechanical properties of the backfill. Compressibility (or bulk modulus) is measured at different stress levels during the course of a test and this information can be used in evaluating the usefulness of the fill in providing ground control and in limiting ground subsidence. The engineering design of mine backfill is becoming an important part of the over all design of underground mine operations. The design problems are sufficently different from conventional civil engineering soil mechanics problems that new test methods and design procedures are required."

Jan 1, 1981

By Charles T. Holland

INTRODUCTION Insofar as I am aware, the term rock mechanics was not in the English dictionary in 1930 when I started my graduate program at West Virginia University. Hence, I never thought that I was undertaking studies in rock mechanics when I undertook to write a thesis on the physical properties of West Virginia coal. In this case, the subject was primarily concerned with the compressive strength of coal, the elasticity of the coal, the physical weathering properties of the coal and its friability. These days investigations of rocks pertaining to such properties are included in the term "rock mechanics". Other than this aspect, the principle interest in this part of my program was that I became interested in the strength of coal from the standpoint of structural purposes, and also became cognizant of its elastic properties as well as its energy storing properties. This research also tied in with a remark that Professor Lawall made in a Mining Methods class in 1928 when he remarked that a peculiar thing was happening in the southern part of West Virginia, namely, in the Pocahontas coal field. His remarks were to the effect that pillars were blowing up in the mines and when asked why he replied the cause was not known. The failure of three-inch coal specimens, especially those in stronger coal, in non-hydraulic actuated testing machines was reminiscent of his description of those pillar bursts or bumps.

Jan 1, 1971

By William A. Beck

"The Old Cline mine, also known as the Old Cruse mine, was first worked for gold in1895. The property was opened by several shafts and trenches; and some stoping has been done, producing several cars of copper-gold ore in the early nineteen hundreds. Chalcopyrite is visible in selected samples; and, with the aid of a mineralite, several samples showing a considerable amount of scheelite were found on the old waste dumps.The mine is in Township 6, Cabarrus County, N. C., 5 miles north of the village of Mount Pleasant, 10 miles northeast of Concord, and about one-half mile south of Watts Crossroads. It is one-fourth mile east of the county road.When examined, the property was owned by H. F. Tompkinson, Concord, N. C., and was leased, with option to buy, by L. Nash. Titles of record were not investigated.As stated above, the Cline mine was first worked in 1895. The property was Purchased in 1902 by J. A. Clark and A. A. Smith of Atlanta, Ga., and worked for gold and copper. No record is available of the quantity of ore removed during these operations.A Bureau of Mines mining engineer3/ examined the mine as, a copper prospect on October 13, 1944.The Cline mine is in an area characterized by flat to rolling topography, dissected by many streams and rivers. It lies in the Piedmont Plateau and Varies in elevation from 700 feet to 800 feet. The surrounding country is partly wooded and partly cleared farm land.A quartz vein occurs in country rock of quartzite and greenstone.4./ The ore occurs in a series of quartz lenses, having a width of 1 to 3 feet and dipping about 750 NE, and striking N. 300 W. All these lenses have fairly sharp boundaries and in some cases are entirely separated from each other, while at other times they are connected by thin stringers of quartz. They can be traced for 1,000 to 1,200 feet by a series of shafts and test pits."

Apr 1, 1946

By E. M. Tignor

A research program to aid development of improved methods for increased production of petroleum from partly depleted reservoirs is a vital part of the Bureau of Mines effort to effect true conservation of that mineral resource. This report presents results of an investigation to identify the clay minerals within some Appalachian petroleum-reservoir sands, the effect of clay content on the fluid-flow behavior of those sands, and the use of brines in water-flooding operations. Permeability measurements using kerosine, calcium chloride brine, simulated oilfield brine, potassium chloride brine, sodium chloride brine, and distilled water were made on reservoir-rock cores. Clay fractions were separated from sand grains of disaggregated portions of each core sample, and the clay minerals were identified by the differential thermal analysis method. Relations of the permeability to various fluids were developed.

Jan 1, 1957

By J. G. A. Stevenson

GENERAL Location of Property THE Stirling zinc-lead-copper deposit is in Richmond county, Cape Breton, about a quarter of a mile southwest from Stirling P.O., and some 45 miles southwest from Sydney. The property is accessible by road for at least nine months of the year, and during the navigation period coastal boats maintain a service touching at the port of Fourchu, eleven miles from the mine. When flying conditions permit, the Cape Breton Flying Club, of Sydney, will carry passengers to or from the property, a service which has been particularly advantageous on two occasions when hospitalization was urgently required. The Company has mining rights on leases Nos. 73-74, 78-80, and 101-104, inclusive, and owns 166 acres at Stirling and one acre at Fourchu. The ore deposit is in lease No. 73. History The Stirling deposit was discovered in the 'nineties', probably about 1895. The original discovery is said to have been made in the bed of Copper creek, which traverses the ore-zone. For a number of years, indifferent development work was carried on with a view to copper production only, and it was not until1915-16 that attention was directed to the possible production of zinc. Previously, the ore had been considered too complex for metallurgical treatment. During the period 1916-24 several operators attempted to develop the property, among them being the Stirling Exploration Company, Stirling Mining & Smelting Company, New Jersey Zinc Company of New York, Hayden & Stone Company of Boston, and The Eastern Mining & Milling Company. Up to 1924, the work was limited mainly to trenching, stripping, ? diamond drilling, and shot drilling.

Jan 1, 1937

By A. W. Hesse

The trend of American construction toward permanence and longevity is noticeable in the more recent coal plant installations; also, the policy of many coal operators has changed from seeking to obtain the desired tonnage from several plants of small capacities to designing a single installation to produce the whole amount. The mine openings and plant of the Nemacolin mine of The Buckeye Coal Co., are located on the Greene County side of the Monongahela River, 73 miles south of Pittsburgh. The map (Fig. 1) shows the general location, also the Lambert syncline. This syncline partly accounts for the selection of the site; the other reasons were the possibilities of rail and river shipments. Two shafts and a slope were sunk to the coal, work starting on all three in the second half of the year 1917. The air shaft was sunk to a depth of 243 ft. and completed in February, 1918; the slope was completed in November, and the skip shaft was stopped at a depth of 21 ft. below the coal, then the concrete lining was stopped 8 ft. above the coal August, 1918. Work on the skip shaft was resumed May, 1923, and sunk to a depth of 60 ft. below the coal by September, but it was not until May, 1924, that the lining was poured. Max. Min. WateR Water during after Sinking, Crouting, Depth or Cu. Yd. Cu. YD. Gal. per GaL. per Opening Size Length Excav. Conc. Min. Min. Air shaft..... 20 ft. diam. 251 ft. 8 in. 4788 1902 475 2 Slope........ 11 it. by 19 it. 1 in. 857 ft. 11500 5200 50 2 Skip shaft.... 32 ft. 8 in. by 12 it. 8 in. 296 ft. 6042 2293 300 3 Fig. 2 shows sections of these openings. The surface plan shows the relative positions of the openings. Coal was first hoisted from the air shaft May 7, 1918, and entry driving was continued; but the coal had to be stored, as the railroad had not been extended from Crucible to Nemacolin. As soon as the slope was driven to the coal and the linings concreted, the entries were driven along projected lines to connect with those advancing from the air shaft, and skip shaft. As soon as the underground connections had been made between the two shafts, the hoisting by buckets was inaugurated at the skip shaft and construction on the fan at the air shaft started.

Jan 1, 1927

By J. E. Shelton

Flotation tests are described on samples of two lowgrade nickeliferous ores of Oregon and Washington. The sample from the Congress mine, Ferry County, Wash., contained 1.2 percent Ni, occurring chiefly as millerite. The sample from the Shamrock mine, Jackson County, Oreg., contained 2.20 percent Ni and 0.78 percent Cu occurring chiefly as pentlandite, nickeliferous pyrrhotite, and chalcopyrite. The millerite in the Congress ore was concentrated by flotatioin with aulfydric collectors in a series of locked tests to recover 73 percent of the nickel as a 7 percent bulk concentrate. By successively regrinding and floating the bulk concentrate, it was further concentrated to 12.4 percent Ni at a recovery of 59 percent and 21.8 percent Ni at a recovery of 50 percent. Attempts at selective concentration of the copper-nickel Shamrock ore were only partly successful because of the intimate association of pentlandite and chalcopyrite. The nickel concentrate, which contained 86 percent of the nickel, had an analysis of 4.42 percent Ni and 1.03 percent Cu. The copper concentrate had an analysis of 18.8 percent Cu and 1.96 percent Ni and contained 48.5 percent of the copper. A bulk sulfide concentrate contained 92 percent of the copper and 01 per¬cent of the nickel and had an analysis of 4.17 percent Ni and 1.63 percent Cu.

Jan 1, 1956

To explain in any depth the industrial relations of Broken Hill I believe that it is necessary to trace some of the many happenings that created the present industrial climate. While appreciating that our relations with the local industry are relatively good, it must be pointed out that to preserve and improve this present situation a duty is owed to everyone connected with the industry (workers, share- holders, etc.) by management and unions to see that just and reasonable agreements are found for any disputes. If the companies ever take the local position for granted it would soon die, killed by someone who may get some short term benefit, but who would lose something of incalculable worth in the long run. Similar- ly if the unions were to adopt some of the "wild cat" methods adopted in other parts of

Jan 1, 1975

By Steven R. Davis

Voyageurs National Park in northern Minnesota, and a 30-mile radius area of influence on the United States side of the International Border, was examined for hardrock (nonferrous metallic minerals and diamonds) mineral potential and environmental sensitivity by the U.S. Bureau of Mines. The investigation also included an analysis of current Metallic Minerals Leasing Rules of the State of Minnesota, and the probable effects of changes proposed to the current rules by the State of Minnesota in order to "encourage mineral exploration and development." The study has determined that the proposed changes to the Minnesota State Leasing rules will have minimal, if any, impact on the likely, foreseeable levels of mineral-related activities in the State as a whole, and particularly, in the area of influence to the Park. Voyageurs National Park management was advised on the extent and character of the proposed rules changes, and on those items of concern meriting a specific and timely response by the National Park Service.

Jan 1, 1994