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By K. Fleck

Energy West Mining Company (EWMC) has implemented a geologic program for improving stability and support requirements along deep two-entry longwall gateroads at its Deer Creek Mine operations located near Huntington, Utah. Together with geotechnical monitoring and concurrent review of mine seismicity in cooperation with MTI staff, it has become possible to improve longwall layout designs for two seam extraction of the Hiawatha and Blind Canyon seams. The geologic program consists of surface and in-mine exploration drilling, surface and in-mine geologic mapping, rock mechanics testing and detailed measurements of changes in depositional and structural conditions during development of every longwall gateroad. The geotechnical program consists of underground measurements at seven locations in two neighboring mining districts located in the Hiawatha and Blind Canyon coal seams under moderate to deep cover. Within the last five years, additional measurements, including data on seismicity and face conditions, have been incorporated into the data collection program for verifying the insitu coal strength and load transfer mechanisms for improving two-seam designs and support systems. Geologic mapping results are also used to predict local stability of headgate and tailgate entries, combining mine roof mapping, stratigraphic profiles of the coal and roof, and depth-of-cover information and dual-seam mine overlays, for use by operations personnel in planning roof and rib support for the retreating longwall sections.

Jan 1, 2012

The first metal-mine accident-prevention course was prepared and published in 1942-45 as a series of seven miners' circulars (Nos. 51-57). The scope of the course has been broadened, revised, and brought up to date, and it is being published as a similar series of seven miners' circulars on accident prevention in metal and nonmetallic mines. These circulars are: 1. Accident Statistics (Miners' Circular 51), dealing with general statistics on accidents and injuries at metal and nonmetallic mines, including causes, costs, and the uses of investigations and reports of all accidents.

Jan 1, 1957

By Randy Wheeler

One of the more difficult topics to address concerns the effects of vibration on historic structures. Not only blast induced vibration, but also vibration from other transient and semi-continuous sources like, traffic, human activity, and environment forces. A common question might be, “What level of blast-re l a ted PPV is considered safe?” A review of some of the papers available from the ISEE Explosives Reference Database on CD ROM shows that 0.50 inch per second was often used. It was not clear on what basis this value was selected except that it represents the low frequency limit for plaster developed by the United States Bureau of Mines in RI 8507. In another case, a limit of 0.20 inch per second was mentioned, apparently simply because it was ten times less than 2.00 inches per second.

Jan 1, 2004

By Tim Hughes, Steve Gannon, Jennifer Abols

"In the past year, two very innovative gold ore processing plants have been designed, built and commissioned by Gekko Systems Pty Ltd. The first plant in Vietnam utilizes conventional crushing and ball milling followed by gravity concentration (Inline Pressure Jig (IPJ) and Falcon concentrator), flotation, intensive leaching (GFIL), the first industrial scale use of AuRIX®1001 ion exchange resin and a cyanide destruction circuit. The second plant, in Australia, uses a 3 stage crushing circuit to crush the gold ore to minus 1mm, followed by gravity concentration utilising a rougher, scavenger, cleaner circuit of IPJ’s and a Falcon concentrator. A direct smeltable gold concentrate is produced as well as a lower grade concentrate for future intensive leaching or sale. Both plants were designed and built within very tight time frames and budgetary constraints. The experience gained during the plants’ design, commissioning and operation are discussed.INTRODUCTIONGekko Systems (Gekko) is a leader in the development of innovative technology for gravity recovery and intensive cyanidation. It provides low cost and metallurgically optimal solutions for its customers. It has also led the trend away from whole ore cyanidation (CIP/CIL) towards gravity/intensive cyanidation (GIL) and gravity/flotation/intensive cyanidation (GFIL) plants. These types of plants offer low capital costs, low environmental impact and maximum return to investors (Rob J Longley et al, 2002). Key to this type of flowsheet is the application of a continuous concentrate unit, such as the InLine Pressure Jig (IPJ), which is designed to produce high gold gravity recoveries at a coarse grind (Sandy Gray, 2003). When combined with other gravity devices, and/or flotation, and intensive cyanidation, using the Gekko InLine Leach Reactor (ILR), very high overall recoveries can be achieved.In 2004, Gekko launched a new range of products called Gekko Modular Systems. The idea was to provide off the shelf, complete solutions for the separation and recovery of complex and free gold as well as the pre-concentration of diamonds. A series of modules were designed that incorporated Gekko manufactured as well as outsourced equipment. Gekko now offers modules ranging from feeding and conveying to crushing, gravity recovery, flotation, intensive cyanidation, refining and detox (see Figure 1)."

Jan 1, 2007

By Gary B. Petersen

The author has developed a seven-step process called the Applied Rock Mechanics (ARM) Protocol that the author has used to solve numerous roof stability problems in mines throughout North America since 1975. It is a practical evaluation process using trained observation, innovative data collection instrumentation, video borehole cameras, analytical processes, and controlled testing methods that have become highly effective in solving ground control problems in every type of underground mine. This paper will describe each of the steps of the protocol and how the rock mechanics engineer applies them to resolve a typical ground control problem.

Jan 1, 2012

By U. K. Custred

Who We Are Farmland Hydro (FHLP) is a Limited Partnership formed by Farmland Industries, the largest U.S. farmers’ cooperative, located in Kansas City, MO, and Norsk Hydro, a large Norwegian company engaged in fertilizer, petroleum and the specialty metals industry. Both of our parent companies have a long history of commitment to the fertilizer industry. This year, Farmland Industry celebrates its 71st year in the business, and Norsk Hydro celebrates its 100th operating year! We employ approximately 300 associates in Central Florida. What We Do Farmland has been active in Hardee County, FL since the 1970’s as a large landowner and citrus grower. We plan to expand this activity into phosphate rock mining. The phosphate rock produced here will be shipped to our nearby chemical fertilizer complex in Polk County, where we produce quality phosphate products - liquid and granular fertilizers. Of the phosphate rock mined, 90% is used to make fertilizer. Other uses include animal feed, vitamins, medicine, light bulbs, soft drinks, film, flame resistant fabric, optical glass, toothpaste, bone china and other consumer products.

Jan 1, 2000

By B. R. Klahold

Each year hundreds of mineral specimens and numerous inquiries regarding tests and analyses of minerals and related inorganic substances are received by the Bureau of Mines. In response to this demand, in years past Information Circulars were published containing a list of laboratories. This paper is a revised version of Information Circular 7523, The listing has been changed from a regional basis to one of States arranged alphabetically and grouped by cities, again alphabetically, with Alaska and Canada listed at the end. All the services given at these laboratories are listed on one page for convenience and brevity. This list is compiled as a public service, and none of the laboratories listed herein are recommended over any other nor can the Bureau of Mines vouch for their results.

Jan 1, 1954

By Peter Duniam, Stephen John Brace

2000 HIGH-TECH SEMINAR Blasting Technology, Instrumentation and Explosives Applications Orlando,Florida,USA July24-27,200O. Objectives:- After completing this session 1. Explain safety issues 2. Do simple initiation design 3. Describe how the system works 4. Demonstrate scanning, hookup, testing and firing 5. Describe hot to do a post blast check 6. Explain how to treat misfired detonators

Jan 1, 2000

By Glenn Norris, Tyler Buckingham

"Gold recovery gains in the order of one to two percent have been realized in 2009 due to changes in the operation of the grinding circuits at Barrick Gold Corporation’s Hemlo - Williams Mill. The initiative known as “split milling” involves milling low grade open pit ore in one grinding circuit and higher grade underground ore in the other grinding circuit under different conditions.The philosophy of split milling involves processing higher grade underground ore at a lower throughput rate and a finer grind while milling lower grade open pit ore at a higher throughput rate and a coarser grind. Bench scale tests showed that the recovery relationship for underground ore sources was much more grind sensitive than that of open pit ore. This relationship proved to hold in the plant. The gold recovery gain due to finer grinding of the higher grade ore is much greater than the recovery loss due to coarser grinding on the lower grade ore. Since the majority of gold is being recovered at a higher rate, this results in higher overall plant gold recovery when compared to the traditional operation philosophy of blending the ore sources.The challenges for achieving the maximum benefits of split milling were two fold; the need to increase throughput on the open pit ore milling circuit and a means of grinding finer on the underground circuit. The former was met with an increase in SAG (Semi-Autogenous Grinding) mill ball charge, a basic “drill to mill” blasting campaign and changes to the primary gyratory crusher. The latter was met with a reduced SAG mill ball charge and a higher milling density. The resulting benefits in additional gold recovered are in the order of $3-5 million per annum.INTRODUCTIONThe Williams Mill processes ore from three different ore sources, the David Bell Mine (DB), the Williams Underground Mine (WUG) and the Williams Open Pit (OP). All three ore sources are located within the Hemlo camp in Northwestern Ontario adjacent to the Trans-Canada Highway. The Williams Mill was built in the mid 1980’s at which time it was designed to process 3,000 dry metric tonnes per day through a 22’ SAG mill in series with a 16’ ball mill. In 1988 a Mill expansion doubled the mill capacity by adding a second identical grinding circuit. A photo of the current grinding circuit can be seen in Figure 1. Today the Williams Mill processes an average of 8,000 tonnes per day of which approximately 60% is from the Williams Open Pit."

Jan 1, 2010

To the industrial geologist, as wen as to the general or historic geologist, the possession of a reliable key to the true order or sequence of the stratigraphy or position of the various upper rocky envelopes of the earth's crust, is, equally, a desideratum of the utmost importance. Of similar value to the two groups of students is the possession of facts which throw light upon the relationships which subsist between the puccessive rock formation of different countries, especially between countries lying close to each other, or within the same great geographical division.But there is necessarily a fundamental distinction which marks the respective limits of the field of observations of the industrial geologist, and the purely historic interest of the general geologist. The former has a more definite though less extensive scope. The scope of the latter is wide and indeterminate. In short, the observations of the industrial geologist are, 'from a commercial or economic point of view, of a more practical character, and are, therefore, intentionally restricted to the study of all geological questions which throw light upon the rocks which yield products of economic value and only include the study of the character and history of other rocks, in so far, as they afford aid to the more perfect comprehension of the best manner in which materials of economic value are likely to be sought, and the best means whereby these products may be secured for the material advantage of the community. The motive of the general geologist-in most cases-is a love of the study of some particular branch or province of the geological field, and the fascination of opening a new volume in nature's library, and the hope of extending the realm of knowledge, however slight, are often sufficient, as a motive, to enlist the energy and life's devotion of the true brethren of the hammer, irrespective of considerations regarding the commercial utility of the pursuit.

By Jeffiey B. Austin, Maurice Tagami

"The ores of the Iberian Pynte Belt are typically massive sulphide ores with very fine grained mineral textures. EuroZinc Mining Corporation is currently evaluating one of the massive sulphide deposits located near the town of Aljustrel, in South Central Portugal. The deposit contains significant grades of lead, zinc and silver. The ores are comprised solely of sulphide mineralization consisting of pyrite, sphalerite, galena and some secondary copper minerals. Liberation requirements for these ores are typically 22 to 25 microns. A selective flotation process has been utilized to produce separate lead and zinc concentrates for sale to off-site contract smelters.This paper outlines the process test results and describes the process parameters required to optimize the process parameters. Ths test program has been conducted in support of the re-opening of the facilities in Aljustrel. The 3500 tpd mining and milling facility was commissioned in 1990 and operated for 18 months before closing. The previous facility was designed to produce three products using a selective copper-lead-zinc flotation process. EuroZinc Mining Corporation is proposing to re-open the operation, selectively mining from a lead-zinc phase of the massive sulphide deposit and produce only lead and zinc concentrates.Results are presented and discussed.PROJECT HISTORY AND CURRENT PROJECT OBJECTIVESThe EuroZinc Aljustrel Project is a potential major producer of lead, zinc and silver located in the Iberian Pyrite belt of south-central Portugal. The town of Aljustrel is historically associated with mining dating to the time of the Romans. The area is rich in pyrite deposits, and sections of the pyrite deposits contain significant zones of copper, lead, zinc and silver. Mining in Aljustrel during the last century (1900’s) included a major pyrite mining operation, which produced feed for sulphuric acid production. Pynte mining operated from the 1930’s to the early 1970’s and a short-lived base metal operation from 1989 to 199 1."

Jan 1, 2000

By McKenzie A. M

The Corridor ore body is so named because it occurs in an east-west zone or corridor of schist bounded on the north by the siliceous conglomerates of Mount Lyell, and on the south by similar conglomerates of the Tharsis ridge (Fig. 1). It was discovered after the geophysical prospecting methods described below had defined a target zone for diamond drilling.Since the proving of copper mineralisation by drilling, the corridor orebody has served the vital function of a convenient known target body for the orientation of more recently developed geophysical methods. Traversing of the orebody by these new methods has provided experience for the evaluation of anomalies elsewhere.Some of the methods applied had not been used in Australia before, and were introduced to the west coast of Tasmania through the undertaking there of modern regional exploration programmes. The authors feel that the information gained could be of assistance to others engaged in geophysical prospecting.HISTORY OF DISCOVERYProspecting in the Mount Lyell district has been more or less continuous since 1881. The first geological report was published by Thureau (1886).In 1934, Blazey and Douglas (1934-38) commenced geophysical surveys at Mt. Lyell using the equipotential method.They obtained anomalous indications in several discrete zones and actually detected the south-east half of the corridor orebody but their work never became the basis for...

Jan 1, 1961

By D. D. Runnells

This study focused on the chemical reactions between uranium tailings fluids and cores of subjacent bedrock from the site of the Cotter Corporation uranium mill at Canon City, Colorado. Actual and synthetic tailings fluids were forced through cores of bedrock. The pH of the effluent solutions was the dominant control on the behavior of dissolved species in solution. The pH depended on the presence or absence of calcite cement in the rocks. Calcite neutralized acidic raffinates and caused the precipitation of iron, manganese, aluminum, and possibly uranium. Chloride, sulfate, and sodium were not retarded upon passage through the cores, and sulfate and chloride should be useful as tracers of escaping tailings fluids. Zinc, copper, cobalt, nickel, uranium, and vanadium exhibited high mobility under acidic conditions and were strongly retarded at elevated pH. Calcium was released due to dissolution of calcite and ion-exchange. Magnesium was not retarded in concentrated solutions, but showed moderate retardation in dilute fluids. Potassium and ammonium both showed early retardation followed by breakthrough and mobility. The behavior of molybdenum was strongly dependent on pH, with retardation at low pH and mobility at elevated pH. Selenium was highly mobile under all conditions. Selenium should be a better tracer than molybdenum for many situations. Precipitation of carnotite appears to control the solubility of uranium and, possibly, vanadium. With the exception of the precipitation of aluminum and silica, all reactions were rapid.

Jan 1, 1983

By Dick T. Atkinson

This report describes the Foster-Miller program that designed, developed, built and tested an automatic, remote control mine car coupler. This new coupler gives the motorman the capability to selectively couple and uncouple cars from the locomotive, to transmit braking intelligence to the coupled car s and to determine if the trip is intact. Hazards due to derailment and runaway cars will be reduced as the brakes are automatically applied in any uncoupled car. Laboratory tests described herein have been completed on the coupler set. Applications include, but are not limited to, the unit train system.

Jan 1, 1976

By Walter D. Holland

This instructors guide is intended for use in a course which teaches metal and non-metal mine inspectors to perform surveys for inhalation contaminants in above ground metal and nonmetal mine work areas. The handbook entitled "Handbook for Surveys of Inhalation Contaminants in Above Ground Metal and Nonmetal Mining and Processing Work Areas? is used as a manual during the course. The manual contains a survey check list, rules for determining if sampling is required, a list of most frequently encountered contaminants, a list of candidate contaminants and their sampling conditions, and a description of control procedures and devices. There are several experiments in this guidebook which the trainees perform to acquaint them with the sampling systems.

Jan 1, 2011

By W. A. Calhoun

"INTRODUCTION A letter from S. D. Strauss, vice president of Metals Reserve Company, Washington, D.C., dated May 22, 1945, to the chief of the Metallurgical Branch, Bureau of Mines, in Washington; includes the following: Because of the present critical shortage that exists in the supply of corundum required by certain industries in war production, the Reconstruction Finance Corporation, Mr. W. C. Keeley, Vice Chairman for Metals and Minerals, War Production Board, has recommended that the Reconstruction Finance Corporation though Metals Reserve Company, proceed with preliminary mill testing of the corundum ore in Gallatin County, Montana, and that the results of that testing be transmitted to the War Production Board. If the results of the testing work are considered satisfactory, Metals Reserve Company will then provide for the actual mining and milling of the ore for the production of corundum concentrates.Pursuant to the above stated recommendation by the War Production Board, Metals Reserve Company desires to make -use of the facilities of the Bureau of Mines testing plant at Rolla, Missouri, for conducting sink and float and other concentration tests on representative samples of the Montana corundum ore. Two, and possibly three samples of ore are to be tested which will have an aggregate weight of approximately 50 tons."

Dec 1, 1947

By L. Nahai

THE OUTPUT ff the mineral industry in 1964 in both non-Communist and Communist Europe showed an upward trend for most countries in keeping with the higher index of overall industrial production. Comparable indexes of mineral industry production for non-Communist and Communist Europe (including the U.S.S.R. in Asia) are not available, primarily because the U.S.S.R. does not report details of its industrial production by industrial sectors. However, available data both in the form of index numbers on production published by the United Nations and based on data as reported to the United Nations by the various countries, and actual production data for selected major commodities published by the various European countries reflect generally expanded output by both the extractive sector and the processing sector of the mineral industry in most of the 26 nations of Europe.

Jan 1, 1966

By Charles A. Bankston, John C. Rowley, Robert J. Hanold, Joseph W. Neudecker

The basic concepts and processes of soil and rock melting as applied to excavation technology are reviewed. The electrically heated, small diameter prototype penetrator development sequence is presented. Emphasis is placed on the different methods of handling the fluid rock and soil melts and their significance in providing new solutions in hole support and debris handling problems. The refractory materials requirements, penetrator life and electrical heater technology are presented. Consolidating penetrators, which form stable glass-lined holes in low density rocks and soils, require no debris removal and will find applications in horizontal holes for utilities, cables, and pipeline installations. Extruding penetrators are being developed to make holes in dense, hard rocks. Melt is conditioned into a variety of debris forms, i.e., glass rods, pellets or rock wool, selected to match appropriate debris handling systems. Unique use in drilling into very hot rock or magma for geothermal exploration or production wells is projected. Some of the results of laboratory and field tests of these devices are compared with theoretically derived operating performance. Coring-consolidating penetrators for geological sampling in alluvium are projected to larger diameter self-propelled and guided coring devices for prospecting along proposed tunnel alignments. Application to the melting of annular shafts for pipeline support piles in difficult conditions such as permafrost has been scoped. Conceptual design studies of large diameter tunneling equipment have indicated the system contributions and economic aspects of rock melting relative to material comminution, wall and roof support and materials handling.

Jan 1, 1974

By T. Norvell, R. Gosine, S. O’Young

"This paper describes the use of dynamic scheduling and discrete event control to provide coordinated control of multiple automated vehicles. This work has been carried out within ongoing research into multi-robot coordination developed around the underground mining scenario. Demonstrations using scaled laboratory models of underground mines illustrate the potential for this technology for full-scale implementation for mine-wide automation. IntroductionIn the past decade, the mining industry has been improving the efficiency of underground mining operations. Robotics and automation have demonstrated the potential to further reduce costs. Tele-operation of underground vehicles from above ground and autonomous navigation have reduced travel delays and allowed for single operator control of multiple vehicles (Bloomquist and Hinton, 2001). Other recent projects include the automation of the digging process as well as the drilling and blasting operations. Infrastructureless guidance systems are also being developed (Bloomquist and Hinton, 2001).Mine-wide automation requires significant developments at two levels: (1) the development of mining robots capable of performing tasks either autonomously or semiautonomously; and (2) the development of methods for automating operations at a systems level. This paper focusses on the latter, and describes a general framework for the coordination of multiple mobile robots in an unstructured or semi-structured environment."

Jan 1, 2003

By Hamid Maleki

Having developed a methodology for estimating mining-induced seismicity resulting from slip along geological discontinuities in 2003, in this paper, the importance of measurements are high-lighted in the study of caving and seismic source mechanisms as applied to mine designs. Geotechnical data is analyzed from four case studies to address cave condition, load transfer, and potential effects on stability and resource recovery in four Utah mines using measurements and observations conducted over the last three decades. Cave conditions are evaluated on the basis of measurements in the gob of a western U.S. operation mining under the massive Castlegate Sandstone and indirectly using the results of measurements and boundary-element modeling at panel boundaries at a mine where strata behave elastically. Together with subsidence measurements and microseismic monitoring, regional caving and load transfer in multiple-panel extractions are addressed while the effectiveness of barrier pillars in reducing stress and seismic response where mining under massive stratigraphic units is analyzed using measurements and three-dimensional computer modeling.

Jan 1, 2006