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By A. C. Johnson, McHenry Mosier

The Bureau of Mines has adapted its activities to needs of national defense and to conditions brought about by the war program . Its work is now oriented solely to war problems . After studying about 1,600 deposits of war minerals , exploration projects have been undertaken on 96 of the most promising , of which 56 have proved successful . These have indicated that 56 million tons of ore of commercial or near -commercial grade can be utilized to meet war requirements . Included in this amount are 1 million tons of tungsten ore ; 4 million tons of chromite ore, 10 million tons of manganese ore , 2 million tons of antimony ore , 1 million tons of mercury cre , and 28 million tons of iron ore . Work done in connection with exploration projects included 172,000 feet of surface trenching , 210,000 feet of drilling , and 21,000 feet of shaft sinking . Nearly 100,000 samples were taken, on which 500,000 analyses were made . Extensive metallurgical tests were made on ore from many of these deposits , both in the laboratory and in pilot plants , in connection with research to develop metallurgical processes for their treatment .

Jan 1, 1943

By H. L. Riley

This report describes the methods and equipment used by the Watauga Stone Co. to drill und blast limestone in a two-level quarry, and to crush, screen, blend, and load this stone. Power requirements per ton of stone produced are reported. The personnel requirements for individual phases of the operation are tabulated in man-hours per ton of stone produced.

Jan 1, 1963

By H. L. Riley

This report describes the methods and equipment used by the Watauga Stone Co. to drill and blast limestone in a two-level quarry, and to crush, screen, blend, and load this stone. Power requirements per ton of stone produced are reported. The personnel requirements for individual phases of the operation are tabulated in man-hours per ton of stone produced.

Jan 1, 1963

By B. Z. Zhong, T. Ong, W. E. Wallace, W. Z. Whong, Z. W. Gu, M. J. Keane

"Abstract-Diesel emission particles (DEP) from an engine operating on the Federal Test Procedure VDC were dispersed in an aqueous mixture of dipalmitoyl lecithin (DPL). a major component of pulmonary surfactant and saline and were tested for genotoxicity using the unscheduled DNA synthesis (UDS) assay with autoradiography techniques in cultured Chinese hamster lung cells. A DEP sample from the same source was dispersed in dimethyl sulphoxide (DMSO) and subjected to the same assay. Both dispersions (in DPL and DMSO) were found to induce UDS in a dose-related manner. After separation of the sample into supernatant and sediment fractions. the activity of the DEP sample was found to reside in the supernatant fraction for the DMSO-dispersed sample; and in the sedimentary fraction for the surfactant-dispersed sample. These findings further indicate that genotoxic activity associated with DEP inhaled into the lung may become bioavailable through the dispersion properties of pulmonary surfactant components.INTRODUCTIONTHE mutagenicity of diesel emission particles (DEP) has been studied intensively (LEWTAS and WILLIAMS, 1986). Carcinogenic effects of diesel exhaust in exposed animals have been reviewed (NIOSH, 1988) and an evaluation of carcinogenic risks to humans from diesel engine exhausts has been published (IARC, 1989). Using components of pulmonary surfactant such as dipalmitoyl lecithin (D PL), dipalmitoyl phosphatidylethanolamine (DPPE) or dipalmitoyl phosphatidic acid (DPPA) dispersed in physiological saline, we have previously shown that diesel soots express mutagenic activities in the Salmonella histidine reversion assay system and in the sister chromatid exchange assay using the cultured Chinese hamster lung (V79) cells. Mutagenic activity of diesel soots dispersed in DPL, DPPE and DPPA was quantitatively comparable to and in some cases greater than, the activity expressed by an equal mass of soot extracted by dichloromethane-dimethyl sulphoxide (DCM-DMSO) (WALLACE et al., 1989).Unscheduled DNA synthesis (UDS) is accepted and frequently included, as one of the tests in the battery of assays used to assess carcinogenic-mutagenic potential -of chemicals (MITCHELL et al., 1983). In this study, induction of UDS in V79 cells by DEP, dispersed in the major component of pulmonary surfactant DPL, was carried out. The purpose of this study is to validate the suggestion generated from our previous work that mutagens associated with inhaled particles may be dispersed or solubilized in the phospholipid component of pulmonary surfactant and become active in such a phase (WALLACE er al., 1989) and to test the fractionated DEP sample using UDS assay for a more complete evaluation of its genotoxicity."

Dec 1, 1995

By Boyd GL

Backfill applied to highwall mining is foreseen as a means to increase recovery of mineable coal to levels comparable with underground longwall mining. This paper describes the progress of research to demonstrate the role required of backfill to achieve real increases in coal rCCOvCrCd h\ hi'eh ss-all mining methods.

Jan 1, 1998

By John Hickey

Management teams at mining companies begin to ask themselves whether to take a company public and, if so, how to do it as they approach the normal threshold for going public in terms of revenue and operating performance. Today, the expense of going public generally suggests the company has at least $20 million in annual revenue and at least $2 million in cash. The revenue number can be lower for mining companies with large reserves. In order to properly attract the investing public, the company must also be operationally strong with robust prospects. The company should have a strong management team and a consistent history of double-digit growth that will continue into the foreseeable future. Assuming the thresholds are met, a company?s management needs to weigh the pros and cons of going public.

Jan 1, 2012

By Joel M. Modd, Stephen P. Holt

"INTRODUCTION Nickel is one of the seven metals designated as strategic by the Army and Navy Munitions Board in 1939, when Congress appropriated funds for the investigation of domestic sources of supply of war minerals. The Mertic nickel lode at Punter Bay, Admiralty Island, Alaska, owned by the Admiralty Alaska Gold Mining Co., was investigated as part of this program.During the period 1919 to 1928, the property was examined the following engineers; L. S. Robe, W. E. Dunkic and S.E. Conbest of the Alaska Treadwell Cr., A, F. Buddington of the Federal Geological Survey, and H. C. Boydell. Henry M. Eakin, in the capacity of consulting geologist, examined the deposit in 1928 and later reviewed data resulting; from exploration recommended by him. In 1936, A. Hoogbom, of the Geological Survey of Sweden, made a very brief report on the deposit based upon information furnished by J. S. Pokovich.A comprehensive study by the Geological Survey of the Punter Bay area, including the Mertic lode, was made during the field season of 1937, with brief examinations in 1936 and 1938. 4/Miyaki, representing the Mitsubishi Company, visited the property in 1937 and in the course of his examination took six samples. G. W. Powel examined the deposit in 1937 and took five samples in the Mertie adit.This report describes the results of the Bureau's work and gives information collected from other sources."

Nov 1, 1946

By G. L. Oldright

In the previous study that has been made by the authors on smelting in the lead blast furnace,4 the furnace examined was one that operated under conditions that have been considered as more or less normal up to the present time. That is, although the furnace had in its charge a large portion of sinter, it also handled considerable quantities of naturally oxidized direct-smelting ore. Other ingredients, such as the limestone, were also added as fairly coarse material. The charges contained only about 24 per cent of lead. Until the changes incident to modern flotation began to take effect, many lead plants doing semicustom smelting in districts where competition was keen and much of the bonanza ore was exhausted were faced with the difficulty of obtaining enough lead to get a sufficient "lead fall" in the blast furnaces to clean the slag thoroughly and to separate it from the lead. A charge containing 24 per cent of lead would have been considered a very rich one by such smelters.

Jan 1, 1931

By G. L. Oldright

In the previous study that has been made by the authors on smelting in the lead blast furnace, the furnace examined was one that operated under conditions that have been considered as more or less normal up to the present time. That is although the furnace had in its charge a large portion of sinter, it also handled considerable quantities of naturally oxidized direct-smelting ore. Other ingredients, such as the limestone, were also added as fairly coarse material. The charges contained only about 24 per cent of lead. Until the changes incident to modern flotation began to take effect, many lead plants doing semicustom smelting in districts where competition was keen and much of the bonanza ore was exhausted were faced with the difficulty of obtaining enough lead to get a sufficient "lead fall" in the blast furnaces to clean the slag thoroughly and to separate it from the lead. A charge containing 24 per cent of lead would have been considered a very rich one by such smelters.

Jan 1, 1931

This paper will review some of the work conducted in the past at the Dynamic Effects Laboratory to examine the use of stress waves and fracture mechanics in understanding dynamic fracture and fragmentation in blasting applications. Along the way, we will use photoelasticity and high-speed photography to better understand the mechanisms of fracture and fragmentation.CITATION:Fourney, W L, 2015. The role of stress waves and fracture mechanics in fragmentation, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 27–40 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Thomas Brynjulfsen, Merete Tangstad, Eli Ringdalen

Manganese ore fines cannot be added to the submerged arc furnace directly as they will prevent even gas flow through the burden. Low gas permeability in the burden will lower the degree of pre-reduction of ore subsequently increase the carbon and energy consumption of the process. In order to utilize manganese ore fines in the furnace, they are typically agglomerated into sinter. In this work, the melting and reduction properties of Gabonese sinter and Gabonese ore have been investigated in pilot scale experiments. Two experiments were conducted, one with 100% sinter as manganese source and one with 50/50 sinter and ore. Lime was used to achieve a charge basicity of 0.72 in both experiments. The composition of slag samples from the excavation of the furnace was established using EPMA(WDS), and the composition of the tapped slag and metal was found using XRF. It was found that while the coke-bed size would determine the tapped slag composition, the melting behavior of the Mn source would determine the mixing with lime.

Jan 1, 2014

By A. H. Jones, J Leasia, S. J. Green, R. D. Perkins

Previously, two groups have conducted studies in order to define the influences of the intermediate principal stress. Mogi studied biaxial compression on prisms of Dunham dolomite and concluded that the intermediate principal stress should be taken into account. His study showed that failure strength increases with increasing [02], but less than the strength increase with increasing confining pressure. Handin, Heard, and Mogouirk's study on cylinders of Solenhofen limestone in torsion also found that the strength depends on the magnitude of [02]. More recent investigations by Mogi varying all three principal stresses independently and by Wawersik varying two of the principal stresses independently provide more detailed data confirming the effect of [02] on failure. All these tests were at low strain rates, and only the work of Wawersik reports measurement of all strains. The investigation here measures axial and transverse strains and included uniaxial and triaxial stress compression tests and biaxial stress tests using tubular samples (axial load and internal or external fluid pressure) at strain rates to 103/sec to provide the stress-strain response and to define the maximum stress or yield locus of Solenhofen limestone and Westerly granite.

Jan 1, 1971

By Mike Cammack, Logan Huppert, Gustavo Azpilcueta

During the summer of 2015, Unisea Inc. sought proposals for the G1 Dock Replacement Project in Dutch Harbor, Alaska. It would be a one year project and construction was scheduled to begin in the spring of 2016. One aspect of the project was the requirement for a layer of armor stone to protect part of the dock. An estimated 30,500 tonnes (37,670 t) of armor stone were needed for the project. The source of rock was the Unisea Quarry due to its proximity to the project and the quality of the stone meeting all the required technical standards.

Jan 1, 2018

"With millions of dollars and thousands of lives at stake, the Iron Ore Company of Canada (IOC) turned to a private wireless network for help.IOC needed a network that possessed the ability to adapt to changes in a nanosecond and to function seamlessly in the most rugged of environments.Canada’s largest iron ore producer required a private wireless network powerful enough to support all mine applications and deliver all data to one central point — without any existing cellular/3G/Wi-Fi coverage.Operations at IOC, a leading global supplier of iron pellets, involved dispatch, drill management and equipment monitoring, pump control and remote video that must service three distinct pits. Due to its setup, the facility does not offer a great deal of flexibility for transmitting signals.IOC serves a robust customer base made up of North American, European and Asian steel producers. It also employs nearly 1,900 people. Catastrophic death and destruction are two very real potential consequences of system communication failure.Technology for tough terrainKinetic mesh technology was born in the wake of the 9/11 terrorist attacks on the United States, one of the most high-stakes emergency situations in U.S. history. The failure of the communications infrastructure on a massive scale that day underscored the need for networking technologies that could provide service even in the most chaotic of conditions.Kinetic mesh networks allow organizations to deploy networks at sites where communications infrastructure has been compromised, as well as quickly establish networks in places where they did not previously exist. Kinetic mesh networks have also demonstrated a better ability to adapt to network changes on-the-fly versus other types of networking technologies."

Jan 1, 2015

By L. W. Ashton

Geochemical exploration guidelines were developed from a study of 460 rock chip samples collected at nine disseminated gold deposits in Nevada. Obtaining high grade Au samples is difficult because gold content is extremely variable, even over 8 m (25 ft) distances. For reconnaissance sampling, pathfinder elements are reliable indicators with threshold values of 100 ppm As, 1 ppm Hg, and 50 ppm Sb. Arsenic is the most reliable of the three elements, being significantly enriched in all deposits. If the pathfinder threshold levels are reached with low Au content, more samples should be collected. Successful disseminated gold exploration requires large numbers of samples.

Jan 1, 1990

By G. R. Hopkins, A. B. Coons

A survey of the petroleum pipe lines by the Bureau of Mines as of May 1, 1923, shows that on that date there was a total of slightly more than 90,000 miles of pipe lines in the United States, having a capacity of approximately 15,750,000 barrels, which is equivalent to one-fourth of the nation's average production for one month. These lines varied in diameter from 2 to 16 inches, the weighted average being 6 inches. The total pipe-line milenge was about equally divided between trunk lines and gathering lines, though the capacity of the former was about four times that of the latter. This was due, of course, to the difference in average diameter, that for the former being 7.4 inches as compared with 3.7 inches for the latter. The common size for trunk lines was 8 inches, and for gathering lines 2 inches. Oklahora, with 19,180 miles of pipe lines, is the leading State in total mileage, with Texas second and Pennsylvania third. From point of trunk lines alone Texas is considerably ahead of any of the other States, a position which it owes to its size and to the growth in the rovement to its Gulf ports. Cali- fornia, though the leading State from point of production, ranks only seventh in pipe-line mileage. This is due to the fortunate location of the Los Angeles Basin fields, some of which are within sight of the refineries to which their oil is delivered or of the port of San Pedro through which their oil is shipped. The last survey of this nature, made in the spring of 1924 by the U. S. Geological Survey, recorded a total mileage of nearly 83,000 with a capacity of approximately 14,450,000 barrels. This indicates an increase of 9 per cent in both mileage and capacity during the two years.

Jan 1, 1927

By A. V. Faiberg

Currently, the interest to conditioning of cyanide-bearing recycled solutions with high-grade of base metals, in particular, copper has significantly grown. This can be explained by two major factors. Firstly, there are strict regulations on cyanides amount in tails and higher cost of detoxification processes. This problem can be easily solved during the ore treatment using the conditioning of solutions and water recycling. Secondly, the presence of other metals minerals which react with cyanide during gold leaching resulting in high cyanide consumption. The presence of copper is a major problem. Many copper minerals react with cyanide with the formation of cyanide complexes-Cu(CN)2-, Cu(CN)32- and Cu(CN)43-. One mole of copper consumes 2-4 moles of free cyanide. Availability of cyanide-soluble copper minerals has deleterious effect on gold leaching (gold recovery, cyanide consumption, tails detoxification, efficiency of gold elution and electrowinning). The precipitation of copper from the solutions improves gold recovery by CIL. The removal and recycling of cyanide allowed the reduction of cyanide addition to the process. The recycling of spent cyanide-bearing solutions based on the removal of copper and the return of cyanide bound in complex compounds for leaching process is an optimal way of solving the problem of gold-bearing copper ores treatment. By using the technology, an adverse impact onto gold recovery process is eliminated and at the same time reducing the cyanide consumption. Today, processes and methods of high-grade copper leaching solutions conditioning before and after gold recovery have been developed, which combine two ways of copper recovery: as a saleable product and cyanide to recover gold and reduce total operating costs. They are Cutech, MNR, SART, Cyanomet, AuGment, Vitrokele, Hannah and Cyanisorb. At the same time, these technologies have not been studied enough and described in literature. Data on parameters and operating conditions as well as introduction is not available. The conditioning technology of recycled solutions developed by IRGIREDMET JSC allows copper to be recovered as high quality concentrate and at the same time free cyanide regeneration in the recycled solution which is amenable to gold leaching. This technology was commercialized at a mine in Kazakhstan in 2008. The removal and recycling of cyanide does not require additional cyanide and is cost-effective. More cost-efficiency is achievable through selling copper concentrates, closed water cycle without the detoxification of effluents and enhanced gold recovery by CIL and cathode quality.

Sep 1, 2012

By Ray Y. Lin

Chemical vapor deposition of tungsten carbide on the surface of steel has been investigated at temperatures between 400 and 550C in an atmosphere containing tungsten hexafluoride, hydrogen and benzene. The tungsten fluoride flow rate was maintained at 20 ml/min. The hydrogen flow rate was at 100 ml/min. The benzene concentration varied from 1.15 to 5.56% in the reaction gas. It was observed that the higher the temperature, the faster the deposition rate for tungsten carbide. But the dependence of the deposition rate on the benzene concentration was not systematic. From the x-ray diffraction analysis, it was observed that W, W2C and WC are all presented in the coating. The amount of each phase presented in the coating depends on the temperature and, to a less extent, on the benzene concentration. The microhardness measurement has also been done for all CVD carbide coatings obtained in this study.

Jan 1, 1992

By J. K. Afidenyo, J. Osei-Owusu

"The Obuasi Mine of AngloGold Ashanti Limited has been operating the world’s largest Biooxidation Plant at its Sulfide Treatment Plant (STP) in Ghana, using the Gencor Biox® technology since February 1994. The Biox® technology was preferred to other alternative methods of treating refractory sulfide ores such as roasting, pressure oxidation and nitric acid leaching due to among other reasons, its lower capital and operating costs, reduced technical risk, relatively benign environmental impact and its ease of operation and maintenance in a remote location.STP has since commissioning succeeded in operating this technology successfully but not without some operational problems. The Plant has seen a number of upgrades and modifications in its circuits which were motivated by cost, operational and throughput constraints.The objective of this paper is therefore to highlight the mine’s experience in the treatment of its complex carbonaceous refractory sulfide gold ores with emphasis on plant operations and improvements such as the Biox® reactors expansion, flotation concentrate upgrade project and neutralization circuit modifications. The Biox® Plant operating cost is also discussed.INTRODUCTIONThe Obuasi mine forms part of the AngloGold Ashanti Group of Gold Mines. It is located in the Adansi West District of the Republic of Ghana. The mine is primarily an underground operation, although some surface mining still takes place. Ore is processed by two main treatment plants: the Sulfide Treatment Plant (for underground ore) and the Tailings plant (for tailings reclamation operations). A third plant, the Oxide Plant, is used to batch-treat remnant opencast ore and stockpiles, of which there are adequate tonnages to keep the plant operational until 2008.Though reference is made in this paper to the Tailings and Oxide Treatment Plants, the main focus will be on the Sulfide Treatment Plant."

Jan 1, 2008

By Nicole E. Evanek, Anthony T. Iannacchione

"Over the past 36 years, a great deal of information has been presented and discussed at the International Conference on Ground Control in Mining (ICGCM). The topic of surface subsidence engineering has resonated throughout each of the 36 conferences, producing 155 related papers. These papers have come from many countries. The major focus has been underground coal, especially longwall mining, but hard rock mining has also received attention. This impressive collection of reports presents a unique opportunity to reflect on the progress made towards understanding subsidence basin characteristics and developing methods to predict and mitigate its impact.In the initial meetings, the focus was on measuring subsidence and developing prediction methods. As understanding increased, predictive methods were developed and tested, especially in North America, China, Australia, Europe, and India. Efforts were made to understand how structures, aquifers, and surface waters were impacted by the formation of subsidence basins. As time progressed, the number of papers dropped slightly and became more focused on site-specific conditions. Most recently, advanced monitoring techniques have revealed new information, spurring a resurgence in research activity. Another recent focus has been on anomalous horizontal deformations occurring in sites with significant relief. Several reports from Australia and one from the US have brought this issue to light. In closing, all of these surface subsidence engineering papers have chronicled the maturing of this most important topic and, in the process, highlighted the importance of the ICGCM in the evolution of our current state of practice.INTRODUCTIONThe aim of this paper is to examine the role of ICGCM in 1) shaping our understanding of the mining induced subsidence phenomena, 2) developing tools to help predict its impact on the surface, and 3) evaluating controls to mitigate these impacts.This analysis involved the consideration of 155 papers available within the ICGCM conference proceedings and listed under the subsidence topic. Three of the papers where only available as abstracts and were not included in this analysis. Four other reports were focused on topics other than underground coal mining-induced subsidence issues and were also not included. It should also be noted that papers dealing with overburden behavior were not included in this analysis. As a result, 148 papers were reviewed and analyzed (Figure 1)."

Jan 1, 2018