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By Jacob W. Young

A casual reading of the geological literature extant to-day would give one the impression that carbon is an element which by some chance or another always existed at or near the surface of the earth, and was never of a magmatic origin. The carbonaceous matter in shales is said to be of vegetal derivation; petroleum is stated to have been derived from vegetable matter or from marine animal bodies; if carbon or bituminous matter is found in igneous rocks or associated with metallic ores, the statement is made that deeply buried carbonaceous sedimentaries were undoubtedly the source from which such carbon or bituminous matter was derived. This, I do not consider a reasonable or common sense view of the matter. Carbon is one of the elements of which the earth is composed. In the table giving the periodicity of the elements it comes sixth in the order of increasing atomic weights. It is an element formed like all the rest were formed, and must be as common to the interior of the earth as the rest of the eighty-odd elements so far discovered. The spectroscopic analysis of light from the sun, and the stars, shows the presence of carbon in the sun and in the colder stars. Thus with carbon, an element, found throughout the universe as well as on the earth, it is entirely reasonable to consider it as present in the interior of the earth with the other elements. Such being the case, the magmatic origin for the various forms of carbon in rocks and ores is a rational and logical conclusion. If but a small fraction of thought and effort was made along these lines, which is made in fostering the idea of the organic origin of the carbon found in the earth's crust, untold advances in this phase of geological science would result.

Jan 1, 1925

Many mining operations are uncertain of what costs they should be achieving. The majority of cost estimates are based on historical costs that have added contingency factors. Historical costs are a valuable source of information but a more precise costing method is necessary. There are several alternative methods for predicting costs. A methodology which provides the best indication of the achievable costs is one using a standard inventory list and a bill of quantities. The model is termed a Basic Principles model and addresses basic design principles and engineering constraints.

Jan 1, 1990

By Melford H. Salsbury

The maximum net return from the sale of ores and concentrates of gold, silver, copper, lead, and zinc accrues to the producer when these mine products are marketed to the best advantage. Data are presented that the producer, especially the small mine operator, can use to survey available markets and make a preliminary estimate of the net return to be expected from an ore, on the basis of typical mill, smelter, and freight schedules. A review of the industry is presented by States in which recent production statistics are given, marketing facilities are discussed, and locations of principal mining districts, custom mills, and smelters are shown. Explanations of treatment processes, ore types, treatment charges, payments for metals, and deductions are given. Published rail and truck freight rates for mine products, based on marketing patterns developed over many years, are listed and explained.

Jan 1, 1964

By Ron Bromenschenkel

The State of California, Department of Transportation is currently retrofitting a major interchange near the San Francisco area. The project is located in a highly traveled area of Oakland with light rail commuter service near many footings. Over 600 micropiles are being used in conjunction with CIDH piles for footing stabilization. A specially designed Soil Nail pile will support footings for a new light rail utility structure. Pile testing features in this contract serve as points of interest for future foundation designs. The presentation focuses on substructure issues of this incterchange retrofit. Both design and construction considerations will be covered. Design Considerations: ? Project Description ? Structure inadequacies ? Design criteria ? Design contraints ? Retrofit strategy ? Consultant analysis ? Pile Designs and Test Sites ? Contract Specifications ? Construction Plan and Cost

Jan 1, 1998

By William H. Pomroy

Fire on surface mining equipment is a serious hazard to life and property. The Bureau of Mines, through a program of contract and in-house research, has developed and in-mine demonstrated reasonably priced, reliable automatic fire protection systems to deal with this problem. This report reviews the development and subsequent testing of systems for haulage trucks, front end loaders, coal augers, dozers, drills, and shovels. A variety of fire sensors, extinguishing agents, and control systems arc discussed in the context of mine equipment designs and operating environments

Jan 1, 1980

In addressing the need for non-degree tertiary training, let us examine some recent reviews of engineering and geoscience education. The Finniston Report (1) criticised the formation of engineers in the UK and stated that this was largely due to the narrow British conception of engineering as a branch of applied science which militates against an effective marriage between theory and application. It also criticised the system for not giving students sufficient grounding in the synthesis of technical, human and financial considerations within their undergraduate courses. As we all know, this report has led to the restructuring of engineering education in the UK. More recently, a Review of the Discipline of Engineering was carried out in Australia by a committee chaired by Professor Sir Bruce Williams (2). The report stated that: Australia has a fairly good system of engineering education that should be made better. more should be done to develop the communication skills of both staff and students. more attention should be paid to changes in engineering practice and the human element in technology. there is a serious shortage of state of the art equipment in most engineering schools. female enrolments in engineering courses should be increased from the current level of about 7% to 20% by 1997. employers should develop a better understanding of the need for continuing education. staff in engineering schools should develop closer relations with employers of engineers. higher education institutions with engineering schools should give financial and other inducements to staff to increase the proportion of study leave or professional development leave spent working as engineers in the business sector. there is considerable room for improvements in the teaching process and in the development of evaluation schemes for assessing the teaching contributions of staff. In its recent report to the Council of the Institution of Engineers, Australia, the Task Force on Engineering Education(3) makes the following points: managerial, entrepreneurial, professional and interpersonal skills should be introduced and integrated into the undergraduate courses but studied in depth as part of continuing education. the continuing education policy of the Institution should be promoted and strengthened with all engineers required to pursue continuing education. the Institution should develop a comprehensive guide to continuing education available from universities, colleges and other public and private sector organisations.

Jan 1, 1989

[RALPH ADAIR Ore Dressing Consultant Bull Mtn. Rd., Asheville, N. C. Phone 4-1693 JAMES A. BARR Consulting Engineer Mt. Pleasant, Tennessee Washington, D.C. BEHRE DOLBEAR & COMPANY Consulting Mining Engineers and Geologists 11 Broadway New York 4, N. Y. I. B. BERENT Engineering Consultants and Contractors Mineral Exploration, Mine Evaluation, Mine Designs and Mine Management 156, Ataturk Bulvarl-Ankara, Turkey BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Monticello, Georgia GLENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" B Howard-Canfield Bldg. Santa Barbara, Calif. COWIN & Co. Mining Engineers and Contractors Consulting Shaft & Slope Sinking Appraisal Mine Development Reports Mine Plant Construction I- 18th St. S. W. B'ham, Ala., Phone 56-5566]

Jan 1, 1952

[RALPH ADAIR Ore Dressing Consultant Bull Mtn. d., Asheville, N. C. Phone 4-1693 JAMES A. BARR Consulting Engineer Mt. Pleasant, Tennessee Washington, D.C. BEHRE DOLBEAR & COMPANY Consulting Mining Engineers and Geologists 11 Broadway New York 4, N. Y. I. R. BERENT Engineering Consultants and Contractors Mineral Exploration, Mine Evaluation, Mine Designs and Mine Management 156, Ataturk Bulvarl-Ankara, Turkey BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Monticello, Georgia GLENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" 8 Howard-Canfield Bldg. Santa Barbers, Calif. COWIN & CO. Mining Engineers and Contractors Consulting Shaft & Slope Sinking Appraisal Mine Development Reports Mine Plant Construction I. 18th St. S. W. Wham, Ale., Phone 56-5566]

Jan 1, 1952

By D. A. Rhys

"The Red Bluff porphyry is a tabular 2 km long north-west trending Early Jurassic quartz diorite to monzodiorite body that intrudes a folded Triassic greywacke sequence in the lskut River area, northwestern British Columbia. The porphyry is 500 m to 800 m northeast of the Snip orebody, which is a southwest-dipping shear-vein, termed the Twin zone that contains approximately 35 tonnes of gold.The intrusion associated with the mineralization is characterized by 0.3 cm to 4 cm phenocrysts of K-feldspar in a mediumgrained plagioclase porphyritic matrix. It is overprinted by pervasive sericite + quartz ± K-feldspar ± biotite (potassic) alteration characterized by intense stockworking of quartz veins containing magnetite--hematite bands. This assemblage is cut successively by quartz veins with minor iron-oxides and pyrite, and by younger pyrite veins with phyllic envelopes. The system is gold-rich but copper-poor, with typical grades between 0.25 g/t and 0.6 g/t Au, and 0.1% and 0.2% Cu. All styles of alteration and veining have similar abundances of these metals. Where southwest- and north-east dipping shear zones are developed in the porphyry, veins of all types are sheeted and foliation parallel. These sheeted zones are interpreted to be syntectonic. Asymmetric phenocrysts, folded veins and oblique foliations developed in the 130 haulageway of the Snip mine imply oblique normally-directed shear on the southwest-dipping foliation.The adjacent Twin zone is a high-grade auriferous shear-vein system that is internally banded with: (1) carbonate-chlorite-biotite veins, with textures indicating formation at least partially by wallrock replacement, and (2) dilatant quartz-sulphide veins. Veins commonly have potassic alteration envelopes that contain biotite ± calcite ± K-feldspar. The zone is highly deformed and schistose, with numerous kinematic indicators including shear bands, asymmetric folds, rotated porphyroclasts and oblique foliations that indicate a normally-directed shear sense which is parallel to that indicated by fabrics within the porphyry.Precious and base metal veins within 2 km or 3 km of the Red Bluff porphyry are zoned. Veins and shear-veins proximal to the intrusion, such as the Twin zone, are typically enriched in gold, copper and molybdenum, and have potassic alteration envelopes dominated by biotite. Distal veins usually contain relatively abundant zinc and lead and have sericitic alteration envelopes. Structures of both types have an Early Jurassic galena Pb-Pb isotope signature.The similarities in structural fabrics and alteration histories in both the Twin zone and the porphyry, the zoning of the vein systems in the area, and the apparently concordant Early Jurassic zircon U-Pb age from the porphyry and galena Pb-Pb dates from the Twin zone and surrounding vein systems suggest that intrusion, semi-brittle deformation and a large mineralizing hydrothermal system were closely related temporally and genetically."

Jan 1, 1995

By Trevor Yeomans, David Yaschyshyn

"Placer Dome (CLA) operates the 90-year-old Dome Mine, in South Porcupine, Ontario.The milling operation currently processes 5 million tons of ore per year, from both the underground and Open pit mining operations, producing 320 000 ounces. The milling process is conventional crushing and grinding, with gold recovery by gravity followed by leach/CIP.Cyanide tailings are impounded in a large (325 ha) tailings area where cyanide is allowed to degrade naturally. Effluent is discharged seasonally during the summer and early fall months to maintain site water balance. Pond water is reclaimed for sole use within the mill process.In 1995, an Effluent Treatment Plant (ETP) was constructed for the purpose of removing dissolved metals and suspended solids. In 1997, an INCO S02/Air cyanide destruction module was added.During this time period, the treated effluent often failed toxicity tests required by the Ontario MISA Regulation, even though effluent chemical parameters were below permit limits. Two studies identified ammonia as the toxicant to Rainbow Trout, and free copper as the toxicant to Daphnia magna.From a literature study, and contacts within the Ontario Mining Association, the use of chelation as a final end of pipe treatment step to render any remaining free copper and metal fractions biologically unavailable was considered. Lab and plant scale tests followed.During the 1999 ETP operating season, the addition of the chelant EDTA (ethylene-diamine-tetraacetic-acid) commenced. To date discharged effluent has passed all toxicity tests.The paper will review the effluent treatment history, current effluent treatment plant operation, and detail the use of EDTA for successful toxicity control.History of Tailings Deposition, and Effluent Treatment From 1910 to 1995Over it’s ninety years of operation, the Dome Mine milling circuit has changed from the original 1910 stamp-mill mercury plant, to today’s modem 14 000 ton per day automated gravity and Carbon in Pulp based plant.By the 19803, a modern mill was operating on mainly underground mined ore. The plant was operating at some 3 800 tons per day, using fairly conventional processing routes.The number 4 tailings dam was being used for tailing’s deposition.All effluent treatment was by natural degradation of cyanide. Discharge was from decanting type structures during the summer months only, maximizing the use of natural degradation no tailings effluent was recycled for Mill use."

Jan 1, 2001

Much attention in controlling blast vibrations has been centred on the probability of causing damage to structures in the area adjacent to where blasting is carried out. In most cases these structures are residential properties and the effect of the vibrations on the occupiers has not been studied to any great extent. This paper looks at the sources of disturbance caused by blasting and their psychological effect. A comparison of ground vibration levels for compliance is examined within the framework of structural and human response.

Jan 1, 1998

By A. K. Mukherjee

The roles of pulsating mechanisms such as the amplitude and frequency of the jig cycle are well established in jigging. Also well established are the roles of the size ratio and the volume fraction of the feed. In iron ore beneficiation plants, these process parameters are optimized to achieve the highest efficiency. However, the role of one of the more important feed characteristics, the liberation characteristic of the feed, has not been studied in detail. Evaluation of the liberation characteristics is difficult because the required washability test is not viable for iron ore feed. In this paper, a new method is proposed in which the liberation characteristics are measured through a separation efficiency value. In the new evaluation method, jigging parameters such as amplitude and frequency of the jig cycle are optimized from the fundamental understanding of the process dynamics and feed characteristics such as size distribution. Then, feeds with different liberation characteristics are tested to evaluate the liberation characteristics of feed in jigging.

Jan 1, 2008

By James A. Brierley

Wastewater from uranium mines in the Ambrosia Lake district near. Grants, New Mexico, U.S.A., contains uranium, selenium, radium, and molybdenum. The Kerr-McGee Corporation has a novel treatment process for waters from two mines, sections 35 and 36, to reduce the concentrations of the trace contaminants. Particulates are settled by ponding, and the waters are passed through an ion exchange resin to remove uranium; barium chloride is added to precipitate sulfate and radium from the mine waters. The mine waters are subsequently passed through three consecutive algae ponds prior to discharge. Water, sediment and biological samples were collected over a 4-year period and analyzed to assess the role of biological agents in removal of inorganic trace contaminants from the mine waters.

Jan 1, 1981

Mining steeply dipping coal seams is a difficult task in the mining industry. Prior to 1996, fully mechanized longwall mining methods along the seam strike direction were tried in China and other countries. Due to its larger coal reserve in steep seams, China made more but still limited progresses on mining in such seams than the other major coal-mining countries. In the last two decades, accelerated research efforts have been made to improve the mining technology in steeply dipping coal seams. Based on these works, a dynamic model of ?R-S-F? system under asymmetrical constrains in mining steep seam is established and the theory of strata control and hazard prevention begin to be formed. The key technologies for mining steep coal seams include: global and regional strata control methods in longwall face, methods for the longwall face machines to sustain static and dynamic loads, and flexible protection technology. These theory and technologies have been successfully applied to mining of steep coal seams of varying thickness and hardness, with hard and soft roof and floor, and with high potential of spontaneous combustion in China. In the recent years, the technology has been introduced to Russia, India, Uzbekistan and other countries where steep coal seams are mined.

Jan 1, 2012

By M. K. Sichone

Anglo Platinum?s Waterval smelting complex based in South Africa operates the Anglo Converting Process (ACP) that produces SO2 offgas. This SO2 offgas is treated in a double-contact, double-absorption acid plant allowing for conversion efficiencies higher than 99.90 %. The catalytic converter used in the acid plant to convert the SO2 to SO3 is a 4-bed reactor loaded with a combination of cesium-promoted and conventional vanadium pentoxide catalysts. In June 2008 there was a shutdown, in which one of the main activities was to screen the catalyst. Before this shutdown, the operator would control the converter pass temperatures manually, via the SCADA, especially during plant start-ups after which some of the automatic temperature controllers were used. After the shutdown, the control philosophy was revisited and all temperature controllers were put on auto mode during plant start up. Furthermore the set points of the pass inlet temperatures were reduced to maximize conversion in the first two passes. The result has been a reduction of SO2 emissions, from a daily average of 50 ? 70 ppm to as low as 20 ppm for similar sulphur dioxide and oxygen concentrations. Further work has been done to maintain high bed temperatures in the third and fourth passes at low SO2 strengths by splitting the gas stream between pass 1 and 2 thus increasing the SO2 content in the gas to pass 2. This increases the temperature of the gas exiting the second pass, which results in higher temperatures in passes 3 and 4. Comparison of the converter performance prior to and after the changes is made. The benefits of partially bypassing the first pass to increase the SO2 content in the gas to the second pass are shown. Conclusions and scope for further work have been drawn from the comparisons.

Jan 1, 2009

By J. G. Donaldson

Optimum conditions are given for chloridizing pyrite, marcasite, chalcopyrite, arsenopyrite, stibnite, and covellite with chlorine gas. The formation of metal chlorides is affected by the time and temperature of chloridizing, and by particle size of the sample. Chloridizing data also are given for chemically precipitated antimony (III) sulfide and copper (II) sulfide.

Jan 1, 1962

By E. Pizarro, A. Videla, G. Compan

One of the main problems related to mining investment decisions is the use of accurate prediction models. Metallurgical recovery is a major source of variability, and in this regard, the Chuquicamata processing plant recovery was modelled as a function of geomining-metallurgical data and ore characteristics obtained from a historical database. In particular, the dataset gathered contains information related to feed grades, ore hardness, particle size, mineralogy, pH, and flotation reagents. A systemic approach was applied to fit a multivariate regression model representing the copper recovery in the plant. The systemic approach consists of an initial projection of the characteristic grinding product size (P80), based upon energy consumption at the particle size reduction step, followed by a flotation recovery model. The model allows for an improvement in the investment decision process by predicting performance and risk. The final geometallurgical model uses eight operational variables and is a significant improvement over conventional prediction models. A validation was performed using a recent data-set, and this showed a high correlation coefficient with a low mean absolute error, which reveals that the geometallurgical model is able to predict, with acceptable accuracy, the actual copper recovery in the plant.

Jan 1, 2015

By W. J. van Niekerk

Ballast Nedam is in Surinam constructing two bridges that will improve communications in the coastal region. The bridges will cross the Coppenam and Surinam rivers and will be founded on open-ended steel piles over 60 meters in length. The majority of piles are inclined and support prefabricated concrete girders forming the roadway. In most locations the stratum is consolidated cohesive layers extending to a depth in excess of 60 meters. For this reason, before pile driving operations commenced, it was decided that a number of test loads would be carried out determine the capacity of the piles. Loading tests were carried out on specially installed piles as well as on piles that would be used as working piles to support the structure. Working piles were dynamically tested using Pile Driving Analysis (PDA) equipment. This decision was based on the inclination of the piles, the cohesive nature of the soil and the increase of strength after the piles are driven. A good insight has been obtained into the real strength of the soil by comparing dynamic and static loading tests on vertical test piles. This made it possible to determine the required length of pile.

Jan 1, 2000

By W. H. Tavenner

The Bureau of Mines gathered test data on the use of a continuous borer in mining an anthracite bed, which was 30 feet thick on a pitch of 15° to 45°. Gangways were driven with the continuous borer, ventilation openings between gangways were driven with a large-diameter auger, and the blocks of coal between completed gangways were mined by the long-hole method, Conveyors were used to transport the mined coal. The continuous borer operated on a coal floor that was frequently soft because of heaving. The continuous borer could not bore openings on a grade exceeding 27 percent (15° pitch). Because 150 was also the lower limit of the pitch, of the bed, the continuous borer was used only to drive gangways. The continuous borer virtually filled the workplace, leaving insufficient space to place heavy-duty timber and cushioning material between the timber and coal back to allow for normal expansion of the uncut coal. The light? weight yieldable steel arch against the coal back gave inadequate support to control convergence, which in a disturbed area sometimes occurred with explosive violence. This exposed the machine operator to a hazardous condition, since a satisfactory solution could not be found, the company discontinued the use of the continuous borer.

Jan 1, 1966

Recovery of Rhenium from Mineral Raw Materials of Kazakhstan

Sep 13, 2010