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By K. Szafran, R. E. L. Seal, M. Tansey

Conversion of hydraulic equipment to fire resistant fluids has been hampered by less than satisfactory component performance and in some cases, catastrophic equipment failure. Concern over identifying possible causes to these problems led to a joint research project between the Potash Corporation of Saskatchewan Mining Limited and the University of Saskatchewan. This paper summarizes some of the results and conclusions derived from this joint project. In this study, the research was limited to evaluating the effects of potash contamination on the performance of hydraulic equipment. Two separate types of tests were conducted in order to provide a basis upon which trends could be established. This study concluded that the presence of potash dust in the hydraulic fluid can induce severe wear over relatively short periods of time. It was also deduced that a contaminant free fluid combined with proper fluid maintenance could extend the performance of hydraulic components using fire resistant fluids even under very severe operating conditions, such as elevated pressures and temperatures. Recommendations as to how to achieve this goal and the practicality of doing so are presented.

Jan 1, 1988

By Clarence Karr

THE BUREAU OF MINES is investigating methods for upgrading tar produced by the low-temperature carbonization of bituminous coal. This survey was undertaken to compile information needed for identifying the ether constituents of low-temperature tar. Physical properties are listed for 1,024 aromatic ethers. The compounds include cyclic and noncyclic, polyfunctional and monofunctional ethers with oxygen joined directly to either one or two aromatic rings. Alkyl groups up through butyl are included. The compounds are divided into 37 groups ranging in complexity from alkoxybenzenes to dibenzopyrans. Compounds containing aromatic ether groups are important constituents of the neutral oxygen components of low-temperature tar. For example, at Morgantown, W. Va., the Bureau of Mines has identified and determined the amounts of benzofuran, 2-, 3-, 5-, 6-, and 7 -methylbenzofuran, diphenyl ether, dibenzofuran, 2,3-dimethyldibenzofuran, and two other dimethyl-dibenzofurans in the neutral oil from a low-temperature bituminous coal tar (103, 104).3

Jan 1, 1962

By James D. Noll, M. Eileen Birch

A monitoring method for diesel particulate matter was published as Method 5040 by the National Institute for Occupational Safety and Health (NIOSH). Organic and elemental carbon are determined by the method, but elemental carbon (EC) is a better exposure measure. The US Mine Safety and Health Administration (MSHA) proposed use of NIOSH 5040 for compliance determinations in metal and nonmetal mines. MSHA also published a rule making for coalmines, but no exposure standard was provided. A standard based on particulate carbon is not considered practical because of coal dust interference. Interference may not be a problem if an appropriate size-selective sampler and EC exposure standard are employed. Sub micrometer dust concentrations found in previous surveys of nondieselized, underground coal mines were relatively low. If a large fraction of the sub micrometer dust is organic and mineral matter, sub micrometer EC concentrations would be much lower than sub micrometer mass concentrations. Laboratory and ?eld results reported here in indicate the amount of EC contributed by sub micrometer coal dust is minor. In a laboratory test, a sub micrometer EC concentration of 31µg m 3 was found when sampling are spirable coal dust concentration over three times the US compliance limit (2mg m3). Laboratory results are consistent with surveys of nondieselized coal mines, where EC results ranged from below the method limit of detection to 18µg m 3 when size-selective samplers were used to collect dust fraction shaving particle diameters below 1.5µm sub micrometer EC concentrations were ?7µg m3. In dieselized mines, sub micrometer EC concentrations are much higher.

By Lewis Stansfield

A rotary displacement method was used to install permanent steel casings for bored piles through an asbestos tip. This method was chosen in preference to alternative driven systems because it was quieter and more versatile if obstructions were encountered. New equipment was designed and made specifically for the project, and stringent health and safety regulations had to be observed.

Jan 1, 2000

By J. C. Duchon

The U.S. Bureau of Mines is conducting human factors research for the purpose of reducing accidents and improving the person-machine interface found in surface and underground mining operations. Miners are exposed to a variety of environmental stressors, e.g., extreme heat, noise, vibration, and adverse illumination, throughout the workday. Exposure to these environmental stressors has been noted in the literature to affect performance on vigilance tasks. Since impaired performance at vigilance tasks can lead to industrial accidents, further investigation of the effects of environmental stressors on human performance is warranted. A brief description of the environmental conditions present in the mining workplace is followed by a review of experiments dealing with the effects of environmental stressors on vigilance task performance. The applicability of past research to actual mining operations is considered.

Jan 1, 1989

By T N. Little

The author contends that geoscience is presently under-utilised in the rock fragmentation by blasting process. Before we can set standards in this area, the following is required: mine geologists need to gain a better understanding of the blasting process and the blasting team needs to obtain a better appreciation of geology. Both groups need to be informed of what can be done to improve blasting outcomes, why it is necessary and how it can be achieved. By working closely together, both the geoscience toolkits and blasting expertise can be applied and focused on priority blast sensitive issues, with potential to improve mine economics and safety. Finally, and ideally, mine geologists need to take a leadership role in raw rock mass data collection and data management, and invited to take an active role in rock mass related behaviour data collection, integration and presentation.This paper attempts to provide insight into all these prerequisites for setting a new standard for collaboration and mutual learning in this strategic opportunity area. The potential for blasting to leverage downstream processes is highlighted. Blasting objectives and blast design principles are introduced along with the required rock mass related inputs. Some hazardous geological materials and environmental conditions are described, along with how they can affect operational complexity.Four case examples are used to illustrate the need for closer liaison between geology and blasting professionals. The first related to grade control blasting, aims to demonstrate how a blasting geology approach can add significant value. Case example two demonstrates how geological models and bench face analysis can assist with fragment control. The third and fourth case examples involve an overview of two case studies where timely geological and geotechnical knowledge input and intervention into blasting activities may have reduced losses due to blast initiated open pit slope collapses.CITATION:Little, T N, 2017. Geoscience input into blasting operations – let’s set a new standard, in Proceedings Tenth International Mining Geology Conference 2017, pp 375–384 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By A. Esterhuizen, S. Essack, H. Joubert, N. Fowler

Tenova Pyromet has developed innovative technologies for copper smelting and electric slag cleaning furnaces. Based on client feedback and requirements, innovative designs have been developed to address key design areas and improve furnace reliability, operability and hygiene. These developments include the NovaLance™ lance system to prevent lance bending on top submerged lance furnaces, the SlagFlo™ slag tapping flow control device to better control bath levels and tapping rate for granulation, and an electrode seal for improved sealing directly onto the electrode casing to allow water-cooled electrode components to be located above the furnace roof. The potential application and benefits of these innovative designs are discussed. INTRODUCTION Tenova Pyromet has a long history in the engineering and supply of innovative electric furnace and related equipment for the base metals and platinum industries. Recently Tenova Pyromet has used its furnace equipment design experience to engineer innovative solutions for top submerged lance (TSL) furnaces, and potentially other furnace technologies. These equipment design solutions are developed to address specific operating challenges and operator requirements. Three of these innovative equipment developments are discussed in this paper. First the NovaLance™ lance technology to prevent lance bending during operation in TSL furnaces, such as used for primary copper smelting, is described. Lance bending has been identified as a significant problem for TSL furnace operators as it causes down time and affects furnace availability. The SlagFlo™ device to control the slag flow rate during tapping has been developed based on specific requirements in the mineral wool industry. The SlagFlo™ device can be used to control slag bath levels in primary smelting, converting and slag cleaning furnaces for base metals including copper. In addition, it can be remotely activated for the safe closing of slag tapholes located upstream from a water granulation system. Finally, Tenova Pyromet developed an electrode seal that seals directly onto an electrode surface. This is a special requirement related to base metals and platinum electric smelting and slag cleaning furnaces where furnace operators prefer to keep the water-cooled electrode equipment above the furnace roof. The seal can be used to seal directly onto the potentially hot and uneven surface of Söderberg, pre-baked and graphite electrodes.

Jan 1, 2019

By R. E. Heithecker

In Kansas, almost every oil well drilled into a limestone formation is treated with hydrochloric (muriatic) acid upon completion. This is done to increase the potential capacity of the well and thereby increase its "daily allowable" production (see p. 9 ), to shorten the time required to produce the recoverable oil, and to increase the quantity of oil recovered ultimately from the reservoir. The porosity and. permeability of limestone formations seldom are uniform throughout the proved area, consequently the production capacities of completed wells vary considerably. Acid treatment of wells tends to increase production capacity and to equalize potential capacity. If offset wells already have been treated with acid, new wells usually are treated to protect the property on which they are drilled against drainage. Even though competitive conditions do not exist in a field, it

Jan 1, 1939

By Roy M. Schnabel

The Fashion Island Boulevard Bridge over the Marina Lagoon in San Mateo, California is an eight span precast, prestressed concrete girder bridge. It is approximately 495 feet in length and 61 feet in width. It is supported on 36" diameter octagonal, hollow precast-prestressed concrete pile columns. The bridge was constructed in 1968 and suffered considerable damage during the Loma Prieta Earthquake in 1989. A damage survey report prepared by the State's Office of Emergency Services (OES) recorded that sixteen of the twenty-one pile-columns sustained heavy to moderate damage from the Loma Prieta Earthquake. The damage consisted of cracking and spalling at the tops of the pile-columns. Spalls at the most heavily damaged columns exposed the prestressing strands and confinement reinforcing which also showed signs of corrosion.

Jan 1, 1993

By David L. Shuck

This report was prepared for the Bureau of Mines to describe the current methods of design, construction, and development of wells for in situ leaching of uranium. The discussion includes the alternatives for well design drilling equipment and fluids, grout formulation and emplacement, well integrity testing and repair, and well development and stimulation. Current practice in these areas was determined through interviews with eight operators of commercial scale in situ facilities and is also discussed. Based on this information plus the authors' experience, recommendations are made regarding well design, construction, and development tor in situ leaching.

Jan 1, 1982

By O. C. Blade

Sales of diesel fuel in the United States during the post year and a half have increased greatly. In 1955 over 174 million barrels were sold of which 80 million (or 46 percent), were used by the railroads, and over 44 million barrels (25 ½ percent) of the fuel were used in trucks, busses, tractors, and heavy moving equipment. Vessels (12 percent), industry (9 ½ ), the military forces (4 ½ ), power plants (2), and oil companies (1/2 percent) account for the remainder. 2/ Dally deliveries of diesel type fuel from refineries averaged over 16,750 barrels during the first six months of 1956 in comparison with 15, 250 barrels during the corresponding period of 1955. 3/ Information on the properties of diesel fuel is very important to the petroleum industry, engine manufacturers, and consumers. To supply such information the American Petroleum Institute and the Bureau of Mines, United States Department of the Interior, under cooperative agreement, are conducting annual surveys of diesel fuel oil produced in refineries in this country.

Jan 1, 1957

By Matthew A. Baumann

Tooth-wear on mining shovels requires continuous monitoring. Worn teeth impede excavation performance, increase energy usage, and increase the risk of lost or broken teeth and adapters. A machine-vision-based automated tooth-wear monitoring system is presented. The system employs a rugged boom or stick-mounted camera to capture images of the shovel teeth. An onboard computer processes the images in real-time to determine the length of each tooth. The current wear state is available via a network-accessible log for on-demand status updates. By continuously recording tooth length changes over time, the logs can be used to estimate wear rates and patterns, permitting comparisons between different G.E.T. configurations, operator behaviour patterns, or material types. This detailed, quantitative data permits site-specific optimizations to wear packages and maintenance scheduling. Automating wear monitoring offers the crucial wear information necessary to minimize maintenance costs and reduce unscheduled downtime. A 37-day field trial in a copper-gold mine demonstrated the ability of the system to measure tooth lengths, compute wear rates, and detect differences in tooth wear based on their position on the bucket.

Nov 1, 2011

By W. A. Calhoun

This report gives results of metallurgical investigations performed by the Bureau of Mines on mineral samples taken during April 1959, from Hawaiian bauxite deposits on the islands of Kauai, Maui, and Hawaii. The bauxite samples were tested at the Bureau's Rolla Metallurgy Research Center, Rolla, Mo., to determine if alumina could be extracted. The results were encouraging. Extraction of the alumina by the American Bayer type digest of crude ore samples from Kauai, Maui, and Hawaii recovered 78.8, 73.1, and 70.0 percent, of the total alumina, respectively. These recoveries were increased to 82.8, 85.5, and 79.5 percent by modifying the treatment, which consisted essentially of calcination and weak caustic desilication to provide a residue. The residue was then treated with calcium oxide and digested in a strong caustic solution to extract the alumina.

Jan 1, 1962

Current mine production planning, scheduling, and allocation of resources are based on mathematical programming models. In practice, the optimized solution cannot be attained without examining all possible combinations and permutations of the extraction sequence. Operations research methods have limited applications in large-scale surface mining operations because the number of variables becomes too large. The primary objective of this study is to develop and implement a hybrid simulation framework for the open pit scheduling problem. The paper investigates the dynamics of open pit geometry and the subsequent material movement as a continuous system described by time-dependent differential equations. The continuous open pit simulator (COPS) implemented in MATLAB, based on modified elliptical frustum is used to model the evolution of open pit geometry in time and space. Discrete open pit simulator (DOPS) mimics the periodic expansion of the open pit layouts. Function approximation of the discrete simulated push-backs provides the means to convert the set of partial differential equations (PDEs), capturing the dynamics of open pit layouts, to a system of ordinary differential equations (ODEs). Numerical integration with the Runge-Kutta scheme yields the trajectory of the pit geometry over time with the respective volume of materials and the net present value (NPV) of the mining operation. A case study of an iron ore mine with 114 000 blocks was carried out to verify and validate the model. The optimized pit limit was designed using Lerchs-Grossman?s algorithm. The best-case annual schedule, generated by the shells node in Whittle Four-X yielded an NPV of $449 million over a 21-year mine life at a discount rate of 10% per annum. DOPS best scenario out of 2 500 simulation iterations resulted in an NPV of $443 million and COPS yielded an NPV of $440 million over the same time span. The hybrid simulation model is the basis for future research using reinforcement learning based on goal-directed intelligent agents.

Jan 1, 2008

By Carl D. Ealy

Work is being done to web enable the FHWA Deep foundation Load Test Database. Originally designed to function in the client server environment via modem, access to the database both for data maintenance and user queries has been upgraded to take advantage of the Internet and current and future information technology innovations. The DFLTD will be part of an Automated Geotechnical Information and Design Aid System, the object of which is to assist those involved with managing and maintaining our nation's highway infrastructure. The system will also meet the needs of university and other research institutions for a statistically meaningful source of high quality data for the development and verification of improved analysis methods, in-situ testing methods, etc.

Jan 1, 2002

The Zeehan field has yielded over 190 000 tons of lead and 26,000,000 oz of silver. Moh of the production took place between the initial discovery of silver-lead ore in 1882 and 1920, and the greatest part was extracted from fissure lodes in the Proterozoic to (?) lower Cambrian rocks. It is demonstrated that the prosperity of the mines relied upon the silver content, which is apparently highest in these beds, particularly where spilitic rocks are associated with them. In contrast, galena occurring in orebodies emplaced in the Gordon Limestone is low in silver.Most of the workings are relatively shallow due in some cases to enrichment related to erosion surfaces.Fault zones within a complex anticlinal structure exposing the Proterozoic to (?) lower Cambrian formations appear to have been major factors in the control of mineralization.

Jan 1, 1968

By L. C. Reese

? Good construction and inspection presumed. ? Capacity-computation factors are independent of construction method. ? To account for variable or uncertain site conditions, anticipated construction problems, and/or minimal inspection, increase factor of safety. ? Conduct load tests and/or develop easily implemented design alternates (e.g., straight shaft in case bell can't be formed) to reduce factor of safety.

Jan 1, 1988

By Pengfu Tan

One copper Isasmelt furnace has been operated in Xstrata Copper at Mount Isa in Australia since 1992. A thermodynamic model and computer program, CuModel, has been developed to model the distribution behaviors of Cu, Fe, S, O, Ni, Co, Sn, Pb, Zn, As, Sb, Bi, Au and Ag, copper loss in the slag, and heat balance in copper smelting process, matte converting process and copper continuous smelting process. The thermodynamic model has been used to model the key parameters in the control of the copper Isasmelt furnace. The effects of the process parameters on the control of the copper Isasmelt furnace have been predicted and discussed. These process parameters include SiO2/Fe, matte grade, coal, temperature, spec air of feed, oxygen enrichment, and MgO contents in slag.

Jan 1, 2006

By G. R. Peterson

To determine the availability of lead and zinc from demonstrated resources, the Bureau of Mines evaluated 235 mines and deposits in 31 market economy countries. Of the 235 mines and deposits evaluated for this study, 186 were evaluated as zinc operations, 30 as lead operations, and 19 as copper operations. Demonstrated lead-zinc resources of market economy countries in 1981 were approximately 4.3 billion metric tons (t) of ore containing 221 million t of zinc and 97 million t of lead. Of these amounts, approximately 154 million t of zinc and 70 million t of lead are estimated to be recoverable. The analyses indicate that demonstrated resources in market economy countries should be sufficient to satisfy projected demand for primary lead and zinc through the balance of the century. The U.S. lead industry will continue to have a comparative advantage over the rest of the world industry, barring any drastic increase in the cost of compliance with pollution control regulations. It appears that the comparative disadvantage faced by the U.S. zinc industry will probably intensify owing to the relative quantity of lower cost zinc resources in other countries, especially Canada, Australia, Mexico, and Peru.

Jan 1, 1985

By W. L. Dare

Tri-axial strains in pillars, created by pillar robbing, were measured in an experiment at the Dysart No. 1 uranium mine near Grants) New Mexico. At this mine, room-and-pillar stoping is used on the advance, and pillars are recovered on the retreat. The are deposit is, for all practical purposes, horizontal. Measuring devices were installed in pillars approximately 90 to 200 feet from the break line, and strains were recorded over a 4-to 6-week period. The measurements indicate that, in general, the algebraic magnitude of vertical strains increased, and the horizontal strains decreased, in turn, indicating that vertical (or near vertical) loads on the instrumented pillars lessened as pillars were recovered.

Jan 1, 1962