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By Radford Schantz

In 1990, the Bureau of Mines (BOM) conducted a mineral investigation of the mines and prospects in the East Mojave National Scenic Area (EMNSA). San Bernardino County. California During field work. BOM identified 701 mines and prospects in EMNSA for which the geology, mineral resources, and mining history were compiled and summarized. Analytical results for 1.188 rock samples collected are tabulated. Total value of identified resources in EMNSA is $5.0 billion. Twenty-four mines and prospects were deemed profitable under current economic conditions. Development could generate considerable economic benefits to San Bernardino County. Potential economic benefits from mining the deposits were evaluated under the following access restrictions for EMNSA: 1) fun access, 2) HR 3460, and 3) S 11/HR 780. Under the full access scenario, cumulative mine revenues are $3.0 billion, cumulative personal earnings at mines and supporting industries are $0.94 billion, and annual jobs at mines and supporting industries are 2,379. Under HR 3460, mine revenues, personal earnings, and annual jobs are $2.9 billion. $0.88 billion, and 2,165, respectively. Under S 11/HR 780, mine revenues, personal earnings, and annual jobs are $1.0 billion, $0.32 billion, and 936, respectively.

Jan 1, 1990

By Alexandra Yuyali

The objective of this research work is to increase the drilling ratio represented in tons per drilled meter (ton/m) to reduce mining costs. One of the key characteristics of this research is the use of the ITH (in-the-hole) drilling rig with a water-powered hammer, also known as Wassara™. The patented Wassara™ in-the-hole hammer is powered by high-pressure water instead of air. To reach the objective, a new design of the blast pattern was implemented considering the following: Burden from 1.7 m (5.6 ft) to 2.8 m (9.2 ft) Spacing from 1.7 m (5.6 ft) to 2.7 m (8.9 ft) Drill diameter from 89 mm (3.5”) to 102 mm (4”) Drilling length from 15 m (49 ft) to 30 m (98 ft) Borehole deviation < 2% The result of this new design is the optimization of the drilling ratio (ton/m); having as a baseline 5.2 ton/m with traditional equipment and obtaining 13.7 ton/m with the ITH drilling, which generates annual savings of $2.43M.

Jan 21, 2025

By Albert J. Phillips

SEVERAL important changes have been&apos; made during 1933 in the compilation and distribution of technical literature to those interested in nonferrous physical metallurgy. The Institute of Metals, of Great Britain, announced that preprints of all its papers would be distributed monthly to all members in combination with their bulletin of abstracts. The A.I.M.E. has announced that it will distribute to all members of the Institute of Metals and Iron and Steel Divisions a monthly bulletin entitled Metals, which will carry preprints of all publications of interest to the members of these two divisions. The American Society for Steel Treating has declared its intention to change its name to the American Society for Metals in order to indicate the broader scope of its activities. The abstract service of Metals and Alloys has been improved and expanded, covering practically the entire field of metallurgical literature. These changes and innovations now provide unparalleled reference service entirely in the English language.

Jan 1, 1934

By AIME AIME

LOCAL COMMITTEES. EXECUTIVE.-W. A. Lathrop, Chairman; R. V. Norris, Secretary; S. D. Warriner, Treasurer; Irving A.. Stearns, W. J. Richards, H. S. Drinker, C. D. Simpson. GENERAL RECEPTION.-Irving A. Stearns, Chairman. Archibald, James, Jr., Pottsville. Lawall, E. H., Wilkes-Barre. Ashley, H. H., Wilkes-Barre. Lentz, W. 0., Mauch Chunk. Ayres, WV. S., Hazleton. Lewis, Albert, Bear Creek. Beard, J. T., Scranton. Loomis, W. H., Jeddo. Bridgman, J. C., Wilkes-Barre. Markle, Alvan, Hazleton. Bunting, Douglas, Wilkes-Barre. Markle, John, Jeddo. Chase, F. M., Wilkes-Barre. Neale, J. B., Minersville. Coroner, Eli T., Scranton. Norris, R. V., Wilkes-Barre. Cote, E. B., Jr., Drifton. Oliver, Paul A., Oliver&apos;s Mills. Davies, W. H., Hazleton. Owens, W. D., Pittston. Davis, H. G., Dorranceton. Pardee, 1. P., Hazleton. Dodge, W. F., Wilkes-Barre. Quin, R. A., Wilkes-Barre.

Jul 1, 1911

By A. Gontijo, A. Matos, P. Lincoln, L. Fonsecail

This paper investigates how to manage and model the vibrations caused by rock blasting in a Brazilian underground mine. Considering the frequent detonations and the previous lack of effective vibration control, understanding, and reducing the impact of these seismic waves is critical. We emphasize the use of the near field model technique, which considers the varied physical properties of different rocks, optimizes blasting plans, and minimizes damage to the rock mass. We detail a case study that demonstrates a comprehensive approach to vibration control. The discussion includes the creation of a monitoring plan, the methodology used, results and the specific challenges and solutions found during the blasting process. This study provides a practical guide for similar future projects. Finally, we present a predictive model based on the collected data, offering insights into the vibrations caused by blasting. This model helps decision-makers minimize the risk of displacing rock blocks in the blasting area, improving safety and operational efficiency

Jan 1, 2024

By I. Gaballah

The chalcopyrite ore&apos;s anodic and cathodic electrodissolution are studied using a Porous Pulsed Percolated Electrode (3PE) reactor. Stationary solid electrode experiments are also performed to explore the mechanism of electrochemical dissolution of chalcopyrite. Experiments with a low - grade natural ore have been carried out at 25 "C in solutions containing 1 M NaCl and 1 M HCl. Galvanostatic and potentiostatic conditions are employed. The influences of current and potential on selectivity of the chalcopyrite ore dissolution are assessed. Anodic oxidation of this ore leads to a preferential dissolution of iron bearing minerals, whereas cathodic reduction is more selective with respect to chalcopyrite. However, in both cases the electrochemical dissolution is incomplete and the current efficiency is low. Design of the actual reactor has to be modified to increase the bed conductivity and to allow continuous experimentations.

Jan 1, 1994

By Lu Yitan, Frances Badelow, Manish Tiwari

"Large ‘design and construct’ projects often present significant geotechnical risks. However, these also present significant opportunities for value engineering in design. These opportunities can be realised through systematic site investigation and close collaboration with the Contractor to dovetail the design solutions to suit construction methods. This paper presents a case study of a large infrastructure project in Singapore which involved design optimization of an earth retention system for a deep excavation in a constrained urban environment. The project also required installation of over one thousand bored piles in highly variable ground conditions - identified as a key risk. Systematic site investigation was undertaken to develop a reliable ground model. A detailed value engineering exercise identified opportunities for design optimization by changing the retention systems and construction sequence in some segments. An innovative low cost ground improvement method was used in some areas to reduce the forces on the retention system. An extensive instrumentation and monitoring plan was implemented for verification of design and to mitigate the remaining risks. This paper includes the lessons learnt on this challenging project, which are relevant to a wide range of construction projects.INTRODUCTIONSingapore has been rapidly expanding its underground Mass Rapid Transit (MRT) network over the past two decades. The Thomson-East Coast Line (TEL) forms part of this expansion and is 43 km long and fully underground comprising 31 stations. This paper describes the value engineering and design optimizations undertaken during detailed design of the earth retaining and support structures (ERSS) for one of the underground stations along TEL. The station, currently under construction, is up to 24m deep and 350m long. The edge of the station excavation is less than 10m away from the existing MRTviaduct. The proposed station is surrounded by high-rise residential and commercial structures, somewithin 2m of the excavation. Land Transport Authority (LTA) of Singapore imposes stringent technical and contractual requirements on MRT construction works to ensure high quality and safety standards. These include minimum requirements for embedment of retaining walls, groundwater control, additional site investigation, instrumentation and monitoring, and compliance to LTA’s Civil Design Criteria (CDC). Any deviations from the minimum requirements can only be approved by LTA after detailed calculations, analysis and field testing are completed and additional monitoring and control measures are proposed."

Jan 1, 1900

By Donald L. Gaughenbaugh

Under the terms of the 1970 amendments to the Clean Air Act, the EPA established national ambient air quality standards for a number of pollutants. Sulfur dioxide (SO2) was one of these pollutants. These ambient air quality standards have had perhaps their biggest impact on the power utilities. In an effort to meet the air quality standards set forth by the EPA, utilities using high sulfur fuels have been forced to install flue gas desulfurization (FGD) systems. The majority of FGD systems in operation today are nonregenerable systems, that is the by-product of the system is disposed of, usually into settling ponds. Limestone slurry is the most common reagent used to remove SO from the flue gases. The calcium carbonate (limestone) slurry interacts with the flue gas, absorbing the SO2 and forming a by-product of calcium sulfate/sulfite which is disposed of.

Jan 1, 1986

By G. Kleyn

"Sub-standard practices and their adverse impact on safety performance remain a challenge in the South African gold mining industry. The purpose of this study was to investigate the root causes of sub-standard practices and the effect on safety performance in South African gold mines. The focus of the study was on the underground production operations at a gold mine in the Free State. The study consisted of three parts: a personal investigation into the causes of sub-standard practices at the mine, a comparison with the results of a cultural study performed at the West Wits mines, and a behavioural survey.The studies described in this article yielded similar results in terms of the key drivers behind sub-standard practices. It was found that substandard practices had a number of causes, and the origin lies within the habits, attitude, and behaviour of employees. Current methods of addressing sub-standard practices and improving safety performance were found to discourage employees from performing work safely and according to procedure. It was concluded that the lack of critical behavioural habits for the given work environment and job title could possibly be the primary reason for the occurrence of sub-standard practices. IntroductionSince the implementation of the Mine Health and Safety Act, 1996 (Act 29 of 1996) and the Mine Health and Safety Regulations, the South African mining industry has been striving to improve health and safety performance and has placed great emphasis on adherence to mine standards.The Act requires employers in the mining industry to report accidents, incidents, and dangerous situations to the Regional Principal Inspector of Mines in their area. The data provided by employers is captured and analysed by the South African Mines Reportable Accident Statistical System (SAMRASS) and made available for public viewing (Department of Mineral Resources, 2011).A review of the national mine-related accident statistics shows clearly that the South African gold mining industry has improved its safety performance markedly over the past decade, but is still facing major challenges (Figure 1). These include meeting the Mine Health and Safety Milestones (Department of Mineral Resources, 2011)."

Jan 1, 2016

By L. Rintala, P. Latostenmaa, T. Kalliomäki, O. Forsén, I. Lehtiniemi, M. Lundström, J. Aromaa

Conductivity is a typical physico-chemical property that has a substantial effect on electrical energy consumption in the electrorefining process. The objective of this study was to examine the validity of regression models predicting the conductivity of industrial copper electrorefining electrolytes. The models were based on data measured with synthetic solutions on a laboratory scale. The variables included in the models were temperature and the concentrations of copper, nickel, arsenic and sulfuric acid. Both first-order and combined effects of the variables were investigated. The measured data were analyzed using MODDE 8.0 modeling and design software. The validity of the models was investigated by comparing the predicted values with tankhouse conductivity measurements taken at the Boliden Harjavalta Copper Refinery in Pori in Finland. During the tankhouse tests, the conductivity and temperature of the industrial electrolyte were measured, and the composition of the electrolyte was analyzed. The measured conductivity values were compared with the predicted conductivities calculated using the developed models. The conductivity model developed in this paper was shown to be more accurate than previous models and suitable for industrial use.

By Kun Li, Shuaishua Yue, Huigui Li, Yuan Ruifu, Yongxiang Xu, Huamin Li

"Coal seams in Tashan Mine of Datong Coal Group in China average 49.2 ft (15m) thick and have been mined by the top coal caving longwall mining method of large mining height. Mining height was 12.5 ft (3.8m) and the top coal caving height was 36.7 ft (11.2m). The gateroad pillar between panels was 124.6 ft (38m). During retreat mining, serious bumps occurred in the gateroads on both sides of the pillar affecting safety production. Therefore, pillarless mining was experimented.Using numerical modeling and comparative study of cases of similar mining condition, it was decided to employ a 19.7 ft (6m) wide pillar, rather than the previous 124.6 ft (38m) wide pillar. Support system for the gateroads was designed and implemented. During gateroad development, pillar failure conditions and entry deformation were monitored. Hydraulic fracturing method was employed to cut off the K3 sandstone along the entry rib so as to reduce the abutment pressure induced during retreat mining. Support reinforcement method combining grouting and advanced reinforcement methods was proposed to insure stable gateroad ahead of mining. Methane drainage and nitrogen injection were implemented to eliminate hazards associated with mine fire and spontaneous combustion.Since the development of gateroad has just completed, and retreat mining has not begun, the effectiveness of the proposed methods is unknown at this point. However, monitoring will continue until after mining. The results will be published in a separate paper.INTRODUCTIONGeneral descriptionTashan mine is located about 15 Km south of the city of Datong, Shanxi province, China (aure 1). The 2014 raw coal production was 25 million mt."

Jan 1, 2015

By Wallace W. Roepke

Four bit designs, two conical and two radial, were tested in coal against a 60° conical reference bit to obtain data on orthogonal cutting forces and primary respirable dust generation. One conical and one radial design were modified by the Bureau of Mines for these tests. Results were mixed: One radial bit used substantially lower overall cutting forces and specific energy than the other bits and was the only cutter lower on energy and most forces than the standard 60° bit. How-ever, it generated more specific and total dust than any other bit. The four bits were also tested for incendivity, with a 90° plumb-bob bit as the reference. The frictional ignition tests were designed to simulate both trimming top rock and cutting such rock during advance on-sump. Results of these tests were also mixed. The radial bits were substantially less incendive than the reference bit and caused no ignitions in either top trimming or sump modes. Only the modified mushroom-tipped conical bit caused ignitions. Bits similar to this modified design should not be used on drum-type miners in gassy mine areas; in-stead, the other types of bits tested should be used to reduce ignition potential to a minimum.

Jan 1, 1983

By Irving Wender

The oxo reaction consists of catalytic conversion of olefins by reacting the olefins with CO and H2 (water gas) to aldehydes that contain one more carbon atom than the starting olefin. The aldehydes are then generally reduced with hydrogen to primary alcohols in a second stage. The two-stage process is called the oxo process. The word "oxo" is derived from the German "oxierung" (ketonization); thus the exact English equivalent of "oxo" is "keto". The oxo process may be applied to nearly all olefins. A wide range of pressures and temperatures may be used in both stages. The pressure range usually employed is 150 to 200 atmosheres. The temperature in the first stage is usually about 140° C. and in the second or hydrogenation stage about 180° C. Although a standard Fischer-Tropsch catalyst may be used for both steps, cheaper catalysts have been utilized to effect hydrogenation of the aldehydes. Most of the information for this, report on the oxo process was gathered from Technical Oil Mission microfilms. T.O.M. Reels 14, 55, and 134 were especially valuable. T.O.M. Report 6 by H. M. Weir was very helpful. Information on the oxo process is scattered throughout documents captured in enemy territory, and the present report does not include all the available data. Some of the information was procured by personal interview. Where, in the body of this report, certain investigators are quoted, the source of the statement is either personal interview or the T.O.M. reports.

Jan 1, 1948

By J. R. Thoenen

[Before 1914 Germany held a virtual monopoly on the world supply of potash for fertilizer purposes. During the World War, potash shipments to the United States ceased, and recourse was had to domestic supplies. High war-tine prisms stimulated interest in various sources, and domestic production increased rapidly. At the close of the war, resumption of shipments from Germany mad other sources reduced prices to below pre-war levels, and, as a result, most of the domestic procedures ceased operations. This experience demonstrated that a domestic source of potash was necessary but that it must be of such a nature that it could compete in price with foreign sources. As a direct result the potash content of thick]

Jan 1, 1941

By Nordau R. Goodman

"IntroductionTHE HISTORY of Nova Scotia's gypsum industry goes back about two hundred years. The extensive deposits found in the Windsor formation, which is Lower Carboniferous, were the first discovered in North America and were known to the earliest .settlers. There has been a steady increase in production from these beds, except for minor setbacks in years of wars and depressions, but at the same time there has been a decrease in the number of operating quarries. This decrease reflects the change from the days of horse-and-cart recovery to the modern, large-scale, highly mechanized operations. In the beginning, almost any outcrop could •supply the tonnage requirements and the most •convenient were selected, but the millions of tons needed to meet present-day needs are not easily found.Despite the size and importance of the Nova Scotian deposits there has been little detailed geological work. Sir Charles Lyell, in 1843 ( 10), established that the beds are Lower Carboniferous and this was confirmed by Sir William Dawson (3) a .few years later. Both Lyell and Dawson agreed the calcium sulphate beds were an original part of a bedded series .but did not consider they resulted from a concentration of sea water. Lyell reached the conclusion that the gypsum was related to volcanic action in the form of heated vapours or hot springs. Dawson believed it was formed by the action •of sulphuric acid on calcium carbonate. The acid, derived from the oxidation •of iron pyrites which was abundant in the older formations, was carried by rivers into basins which were rich in shells."

Jan 1, 1954

By S. E. Pérez-Fontes

An experimental study on the oxidation of chalcopyrite (CuFeS2), pyrite (FeS2), covellite (CuS) and chalcocite (Cu2S) particles was conducted by means of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. The oxygen concentration in the process gas was set to 40% and 70% (by volume) and a heating rate of 40°C/min was used. Response variables included the temperature of incipient reaction, the total exothermic heat of reaction, particle mass, morphology and mineralogy of the reacted particles. Based on the experimental data and phase stability calculations, reaction mechanisms were proposed to represent the behavior of the particles during oxidation. The reaction mechanisms were verified by X-ray diffraction (XRD) analyses of the oxidized particles and by thermochemical and mass balance calculations to reproduce the DSC and TGA data. Overall kinetic models were developed to represent the evolution of the exothermic heat of reaction as a function of time.

Jan 1, 2007

By G W. Clamp

The most traum atic event within the lUK coal industry during the last 30 years was its privatisation. Who were the relatively unknown people from RJB: white knights or robber barons? This paper highlights the strong safety and progressive engineering cultures th at existed and continues within the company. A long-term view of the business coupled with proven professionalism is amply developed. Quite dearly, to revert to private ownership is not a return to Victorian values but ‘back to the future’.

Jan 8, 1997

By A. L. Engel

This report is a compilation of results of brief preliminary tests on sulfide ores that contained gold and silver and, in some cases base metals. It is a companion paper to a recent similar report on oxide ores. Simple treatment methods employing the least possible equipment sometimes produce satisfactory results on marginal ores and in small-scale operations. Investigations of typical ores from newly discovered or recently explored mining districts have been made in continuation of a long-established part of the hydrometallurgical and ore-dressing program of the Reno station, Bureau of Mines. The purpose of such investigations is to encourage the search for and development of mineral resources and particularly to assist in the economical exploitation of low-grade and marginal ores as well as the conservation and recovery .of values in products that were discarded from former operations because of inability to treat them profitably. Several of these investigations have been limited to preliminary tests of samples from prospecting operations, whereas same involved samples of old dumps or tailings piles. The test work in these cases was not extensive enough to warrant publication as individual reports, but is of considerable interest inasmuch as it indicates the possibilities as well as the limitations of treating the respective materials. The samples were representative of the districts from which they wore obtained, so this information should be helpful in the future development of these districts.

Jan 1, 1951

By G. H. Blackwell

Open pit mine management must ensure that sufficient trucks are available and are being used effectively for production, and that operating costs are under continued control and review for improvements. This paper describes methods for estimating truck fleet requirements which have been used effectively at large- and medium-sized open pit mining operations. Applied to commonly available data, multiple regression analyses can indicate when mine plans should be revised toward optimizing the number of trucks required. Prediction of major cost items for budgetary purposes is addressed, along with an example of how readily available production data can be used to reduce costs systematically.

Jan 1, 1999

By H. M. Fisher, R. E. Snow, S. C. Sun

RAPID colorimetric estimation of the amount of transparent minerals has been applied success- fully to instream mill products at the cryolite flotation plant of the Pennsylvania Salt Mfg. Co., Natrona, Pa. Apparatus used was a Bausch & Lomb monochromatic colorimeter. The optical assembly of the colorimeter, shown in Fig. 1, passes light from a 6-v, 32-cp, prefocus incandescent lamp through two condensing lenses, a heat-absorbing filter, an aperture-control diaphragm, an interference filter, and a sample container. The light finally strikes a barrier-layer photocell and the output current of the photocell is measured by a galvanometer. The engraved index line of the collective lens, located between the lamp and the galvanometer, is imaged upon the transmission scale of the colorimeter by the galvanometer mirror. Reflected light from the galvanometer mirror, the position of which is determined by the output current of the photocell, enables reading of percent transmission throughout the mineral sample being tested. The colorimeter, Fig. 1, was standardized as follows: 1-The colorimeter was connected to a Sola constant voltage transformer, A, of 6-v output operated from a 110-v ac supply. 2-Turning the toggle switch, C, illuminated the transmission scale, B, and the control knob, D, was adjusted with a blank in the optical system until the hairline on the scale read zero. 3-A No. 430 interference filter, E, was inserted into the filter channel, F. &--A test tube, G, containing 7 cc of distilled water was pressed into the sample space, H, and the fine adjustment knob,

Jan 9, 1954