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By Richard D. Miller

This publication contains routine analyses and related source data for 434 gas samples from 16 States. These samples were collected during calendar year 1961 as part of the continuous survey for the occurrence of helium in natural gas conducted by the Helium Activity of the Bureau of Mines. The analyses herein were made by mass spectrometer and Frost helium apparatus. The most important helium resource discovery made during 1961 was the Table Mesa field in San Juan County, N. Mex. This field, Which has an estimated recoverable helium reserve of 850 million cubic feet, is now supplying gas containing approximately 5.4 percent helium to the Bureau of Mines Navajo Helium Plant at Shiprock, N. Mex.

Jan 1, 1964

By D. Caruso

The health and financial costs of cumulative injuries are plaguing the mining industry. Industry leaders are concentrating on reducing the risk of injury to their workers through design and redesign of work environments. While ergonomics is not a currently regulated field, many mines are realizing that the only way to tackle their most costly injuries, cumulative injuries, is to make the proactive choice to understand those injuries, their root causes and to make workplace changes to prevent them from occurring. Reduction of these injuries not only improves the health and morale of the workers but increases productivity and profit for the companies. Knowledge and reporting of ergonomic risk factors by employees and ergonomics committees is key to these changes and to the reduction of cumulative injuries. NIOSH is developing strong relationships with industry associations and equipment manufacturers to leverage their communication abilities to transfer knowledge to their customers and make a difference in the health and safety of U.S. miners. The benefits of a formalized approach to reducing these injuries along with examples will be presented.

By J. B. Dilworth

The purpose of this paper is, first, to give a general account of a little-known coal-district of SE. Kentucky, its topography, drainage, and mineral resourcee, for those who may be interested in its economic development; and secondly, so to describe the geologic features of the field as to furnish available data to those engaged on the broader problems of Appalachian coal-geology. The data from which the major portion of the paper has been prepared were obtained, in professional investigations for private individuals and corporations, within the last decade. The area under review, defined by a heavy line on the map, Fig. 1, lies between Little Black and Pine mountains, and extends from Harlan on the west to a N-S. line crossing Looney creek 3 miles from its mouth on the east. This area can be divided for description into a Western and an Eastern Division. The character of investigatioil pursued in the Western Division, below Fugitt creek, was very different from that employed in the Eastern. In the former, only a rapid reconnois-sance was attempted: such coal-openings as had been made by prospectors or by citizens in obtaining fuel were visited, their

Jan 1, 1913

By C. C. Birch

Due to grade estimation uncertainty, two statistical errors can occur. The Type I error is where material is classified as ore and mined, despite the true value being below the break-even grade. This material is dilution. The Type II error is where the material is estimated to be below the cut-off grade and is classified as waste, although the true grade is actually above the break-even grade. This material is not mined and is lost. The uncertainty was assumed to follow a normal distribution in a previous study. For this study, estimated block values are compared to those determined after mining (the best estimate of the true grade). This actual data from four mines shows that the uncertainty follows a Laplace. There is no single solution regarding adjusting the cut-off grade away from the break-even grade, considering estimation uncertainty, that could be applied to all gold mines. However, adjusting the cut-off grade downwards (up to 22% for one mine) is noted when optimizing the profit considering grade uncertainties. This type of adjustment could open up significant mining areas and extend the life of the mine.

Jul 2, 2022

By N Collins, A Woodley, A N. Danoucaras, C McCombe, N C. Kunz

Over the past decade, the mining industry has come to recognise the importance of water both to itself and to others. Water accounting is a formalisation of this importance that quantifies and communicates how water is used by individual sites and the industry as a whole. While there are a number of different accounting frameworks that could be used within the industry, the Minerals Council of AustraliaÆs (MCA) water accounting framework (WAF) is an industry-led approach that provides a consistent representation of mine site water interactions regardless of their operational, social or environmental context that allows for valid comparisons between sites and companies.The WAF contains definitions of off-site water sources and destinations and on-site water use, a methodology for applying the definitions, and a set of metrics to measure site performance. The WAF is comprised of two models: the input-output model, which represents the interactions between sites and their surrounding community, and the operational model, which represents on-site water interactions.Members of the MCA have recently adopted the WAFÆs input-output model to report on their external water interactions in their Australian operations, with some adopting it on a global basis. To support this adoption, there is a need for companies to better understand how to implement the WAF in their own operations. Developing a water account is non-trivial, particularly for sites unfamiliar with the WAF or for sites with the need to represent unusual features. This work describes how to build a water account for a given site using the input-output model, with an emphasis on how to represent challenging situations.CITATION:Woodley, A, Danoucaras, A N, McCombe, C, Kunz, N C and Collins, N, 2013. A robust methodological approach for mine site water accounting, in Proceedings Water in Mining 2013 , pp 335-342 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

By D. Rudenko, C. T. Aimone-Martin, J. K. Ratliff, I. G. Wong, J. Aiken, R. E. Burnham, T. A. Davidsavor

A small quarry blast was conducted with a maximum of 90 pounds per delay and shortly afterwards, area residents sensed ground motion and building shaking indicative of an earthquake. In addition, seismometers up to 500 miles (800 km) away recorded a magnitude 2.8 earthquake located in the area. Positioned in a seismically inactive area, southern Minnesota is not known for earthquakes. The earthquake was originally described by the USGS to be a surface blast at the quarry. Analysis showed that the earthquake occurred shortly (approximately seven seconds) after the quarry blast some distance away and well below the surface. This paper describes the evaluation of the “seismic events” including the blast, the following earthquake, initial governmental response, and provides the framework for assessing the relationship between the blast and the earthquake. The paper also discusses management of large volume claims from a complex event and presents a claims management strategy with best practices.

Feb 6, 2023

By W. Carter, P. Chaubal, K. Spaleck, M. Schoeman, J. Bobek, W. Seegers

Keywords: Pyrometallurgy, steel, hearth, blast furnace The Mittal Steel Company operates about 36 blast furnaces on four continents. Furnaces range from 1100 m3 to 4800 m3 inner volume. The focus of the group is to push for increasing productivity and increasing campaign life. This has been especially challenging, as many of these furnaces were not equipped for long campaigns during their prior rebuilds. Monitoring and operating practices have to be modified to match the new philosophy. Mid-campaign hearth repair strategies and hearth design philosophies have had to be reconsidered. The paper describes experiences with the current hearth designs and measures taken for hearth life extension. Additionally, the philosophy of recent hearth re-designs is discussed.

Jan 1, 2006

By V. Miller

C. Hertzler The difference of means of milling characteristics by rock and ore type is tested in a statistical manner in the paper. The null hypothesis being tested is that the sample means of two different populations are equal. It is assumed that the null hypothesis is true when performing the test. Because of this, acceptance of this hypothesis leads to the conclusion that the sample means of the two different populations are equal (or there is no significant difference between the sample means), not that the samples come from the same population, as the author asserts. Rejection of the null hypothesis leads to the conclusion that the sample means of the two different populations are not equal. A P value for this test is reported in Table 2 and is incorrectly identified as the probability that the two samples came from different populations. Actually, what was recorded was 100(1 - p) where p is the usual p-value. The usual p-value measures, on a scale of zero to one, the extent to which the data agree with the null hypothesis. It is the probability of observing a value of the test statistic (Z score) that is at least as contradictory to the null hypothesis as the one computed from the sample data (McClave and Dietrich II, 1982). The author makes no mention of the fact that were these tests to be conducted together, the chances of determining that the null hypothesis is not true when it is really true are increased considerably (Snedecor and Cochran, 1980). This is a multiple comparisons problem and should be dealt with accordingly. The usual methods involve adjusting the level of the individual tests. Table 2 reports an incorrect 100(1 - p) value in the comparison of concentrate grades for other rock types with .30 to .69 % Cu vs other rock types with .70 + % Cu; 86 % should be 98.6 %. Although the article can be criticized for poor data presentation and discussion of that data, the point the author makes regarding the use of these statistics in the ore reserve estimation process is well taken. It does not appear that inaccuracies in the statistical interpretations have hindered that usefulness. References McClave, J.T., and Dietrich, II, F.H., 1982, "Statistics," Dellen Publishing Co., San Francisco and Santa Clara, CA, 766 p. Snedecor, G.W., and Cochran, W.G., 1980, "Statistical Methods," The Iowa State University Press, Ames, IA, 561 p. Reply by V. Miller After reading Ms. Hertzler's comments, it appears that the differences noted were basically semantics. If the paper is ever presented at a math symposium, some changes will be needed. When deciding the best way to present the data to mining engineers and geologists, I decided that presenting the probability that the two sample groupings came from different populations (reverse to the Null hypothesis) was easier and would require less verbage to explain. Hence, the 100(1 - p) difference which was noted. Ideally, I would have preferred to give the recovery and concentrate grades, then comment which ones had significant differences. Unfortunately, Kennecott Corp. did not grant permission to publish the ore body's actual recoveries and concentrate grades. The conclusion is that there was, as expected, a relationship between the ore's geologic properties and the metallurgical properties, and by determining this relationship, the overall mineral model was greatly improved.

Jan 8, 1984

Discussion of the paper of B. H. Dunshee, presented at the Butte meeting, August, 1913, and printed in Bulletin No. 30, August, 1913, pp. 1511 to 1531. GEORGE E. MOULTHROP, Butte, Mont.:-The recording for the first time by Mr. Dunshee, in a readily usable form, of the various systems of square-set framing applied in the Butte district is a valuable contribution to mining information. The many different methods of framing employed, due to the individual ideas of superintendents and foremen of segregated companies, have given full opportunity to determine the best framing for the conditions as found in these mines, and the final adoption of a system uniform for all the mines has come about through a study of these various methods and an experience covering a period of many years. The sawed 10 by 10 in. and 12 by 12 in. timbers undoubtedly give the best satisfaction; and the style of framing the sawed timber that under all conditions has given the best practical results is that used in the Anaconda group and other mines, described and recommended by Mr. Dunshee. In this framing the posts have a horn 2 in. high and 6 in. square, the cap end having dimensions of 3 by 6 in. Instead of the framed girt shown in the drawings of the Anaconda group, the 6 by 10 in. girt adopted at some other mines, which fits into the cap and post framing with no other preparation than cutting the timber to the necessary length, fills all the necessary requirements for strength and affects a material saving in timber and labor. This, as Mr. Dunshee states, is without doubt the type of framing which would be adopted as a standard for 10 by 10 in. sawed timbers if sawed timber sets were to be used in the future generally. But saw-timber for the mines was becoming scarce and expensive, and round timber for the square sets furnished an alternative which provided, at greatly reduced cost, material which in every way supplied the requirements of the mining conditions. The use of the round timber with a satisfactory framing makes available a conveniently located and large source of supply which up to this time has served no useful industrial purpose. Particularly is this true of small timber, which is still standing in great quantities in the forests where the trees more desirable for commercial purposes have already been cut and marketed.

Jan 11, 1913

By R. F. Chaiken

The Bureau of Mines has conducted a study of mine fires in the Anthracite Region of Pennsylvania to determine the most effective approaches to fire control in this area. The problems involved in controlling an anthracite fire include the geological and mining conditions in this area, the propagation characteristics of anthracite, the fire control methods available, the hazards associated with these fires, and the mar-ginal effectiveness of past fire control projects. From this genecal background, fire control options were discussed as they apply in ISBO to the Centralia mine fire. Probable effectiveness, feasibility, and costs were assessedv The options evaluated include four excavation plans, flooding, hydraulic flushing, water curtain isolation, mining to construct an underground carrier, burnout control, and relocation of the community. The most advantageous from a technical viewpoint is an excavation method combining complete excavation of the fire zone within the borough with trenching to confine the remaining fire. It appears that for many anthracite fires, as for the Centralia mine fire, there are no available control measures that have a moderate cost, are proven effective, and produce minimal disruption on the surface.

Jan 1, 1983

By William H. King

The Fannie Ryan deposit is situated about 9 miles northwest of Boulder City, Clark County, Nev. at an altitude of about 2,000 feet on the north side of the River Mountains. The deposit is covered by several unpatented claims owned by Fannie B. Gulick of Las Vegas, Nev. The Boulder City deposit is within the Hoover Dan National Recreational Area. It is situated about 3 miles southeast of Boulder City in sec. 23,T. 23 S., R. 64 E., Clark County, Nev. The Deposit was covered by several unpatented mining claims owned by S. R. Whitehead of Las Vegas. The deposits occur in sedimentary beds of the Muddy Creek formation that overlie older volcanic extrusive. The manganese minerals occur as soft oxides of the wad type. The exploration was conducted by the Bureau of Nines in cooperation with the Federal Geological Survey and comprised a study of the geology, mapping of the areas, and development by shaft sinking; diamond drilling, and sampling. On the Fannie Ryan Gulick property the work consisted of cleaning and sampling seven old trenches on the outcrop and diamond drilling seven holes totaling 1,482 foot. At the Boulder City deposit 188 feet of drilling was done in two holes. A 4- by 6-foot shaft was sunk to a depth of 44.5 feet, and the north and south sides of the shaft were sampled.

Jan 1, 1950

By William R. Wayment, David E. Nicholson

A modified percolation - rate test is proposed for use in determining flow rates through hydraulic backfill ; in contrast to the conventional test , a percolation- rate versus void - ratio relationship is established . requirements and a detailed test procedure are described . Equipment Results of a conventional test are compared with those of the proposed modified test . The proposed modified test method yields more accurate , realistic , and usable percolation- rate ( permeability ) data . The significance of obtaining accurate percolation rates for use in analyzing waterflow through hydraulic backfill is discussed .

Jan 1, 1964

By D. R. Spears

Conventional round tank thickeners have been widely used in the mining industry for many years. The mining industry was well satisfied with the ability of conventional thickeners to improve minerals beneficiation operations. However, development of improved flocculants (the polyacrylamides) made possible much more rapid settling rates, since polyacrylamides produce large flocs rapidly (unlike starch or inorganics). Traditionally considered to be a slow operation if maximum underflow density was achieved, and therefore there was some justification for the expense. Thickeners required large volumes to permit sufficient time for settling. The oversize not considered a drawback but the initial capital cost was. In high rate thickeners, a bed of thickened material is allowed to build around the feedwell, even above the bottom of the feedwell. The slurry is fed directly into the bed at a velocity that allows the material to be evenly dispersed over the thickener area This more efficient use of settling area allows a higher solids throughput per unit surface area (rise rate). In this paper, high rate thickener rise rates and polymer consumption are compared.

Jan 1, 1998

By Alton G. Woody

Like so many installations of its type approaching middle age, the ore processing and shipping facilities in Puerto Ordaz, Venezuela, have taken a lot of twists and turns in their lifetime. The object of this paper is to lead you through these twists and turns and some of the reasoning for them. The need for additional sources of iron are in the United States became evident during the time of the second world war. An exploration team from U. S. Steel located further high quality direct shipping iron are in commercial quantities near Ciudad Bolivar, Venezuela in 1947. Basic decisions were made to develop these reserves for export via the Orinoco River through a new shipping port to be built at the confluence of the Orinoco and Caroni Rivers. The basic concept was for the ore to be loaded directly to ocean going vessels. This was something of a gamble since the basic economics depended upon successfully opening up the main channel of the Orinoco River to deepwater vessels, and the Bethlehem Steel mine in the same area was already working with shallow draft river boats and a transfer station on the coast. Always, the basic philosophy has tended to be to plan with expansion in mind. The original conveyor systems were 1.52 m (60 inches) wide with 200 idlers, whereas 1.07 m (42 inches) or 1.22 m (48 inches) wide conveyors could have carried any production foreseen at the time of installation. Stockpiles have been located and designed with room for expansion. Basic designs have had dotted line future expansion blocked in.

Jan 1, 1978

By Robert R. Perron

The U.S. Bureau of Mines is engaged in many diverse programs for improving mine safety. Of particular interest to the Bureau are new and improved means for minimizing the hazard of fire which can be initiated by prolonged low energy electrical faults on trolley line systems. When a high energy fault occurs on a trolley line, wherein the current exceeds the magnitude normally drawn by legitimate loads, such as locomotives, then the circuit breakers at close-by power rectifier sets trip. Tripping of the breakers not only protects the equipment at the rectifier sets, but also disconnects the energy source from the fault and thereby minimizes the fire risk. However, the fault current is frequently of a level substantially below that required to trip the overload breakers. When the fault is a substantial percentage of the set level of the breakers, the energy dissipated by the fault is frequently sufficient to clear the system by rapidly burning itself clear. Such a fault is often short-lived and does not present as serious a fire risk hazard as a prolonged, much lower energy fault, wherein the energy level is too low to clear the system. The breakdown of a trolley line insulator, in which there was a 20 or 30 ampere leak, would represent such a fault or illegitimate load and a substantial fire risk.

Jan 1, 1974

By Fabio Mielli

Encompassing between 20 and 40 percent of the typical mining operational costs, energy in mining operations is a growing concern for the industry. However, this concern is a complex, multi-faceted variable that involves government regulations, societal pressures, cost and competitiveness. Managing energy efficiency is becoming a keystone of successful companies. The suggested energy strategy in mining and mineral processing operations must follow a well-structured approach to include the following: ? Understanding where energy is being used and why. ? Recommending and implementing energy conservation measures. ? Driving visibility to targets and results. ? Leveraging the energy spent across the enterprise. ? Developing a robust energy and sustainability strategy. Additionally, it must ensure that all decisions support the financial and operational integrity of the business.

Jan 1, 2012

By N Clarke, A Barros

Preconcentration of run-of-mine subgrade and marginal ore by screening has the potential to substantially improve the economics of mining, particularly for large, low-grade orebodies, and to reduce environmental impacts. It has recently been the subject of a major research effort by a joint public-private research body, CRCORE. Yet despite this, there appears to have been only one fully commercial installation, at Bougainville Copper Limited in the late 1980s. Two reasons for the limited application are that not all ores have suitable properties and the economics of all pre-concentration processes on low-grade materials are highly sensitive to the precise balance of mass and value recovery and to the pre-concentration process cost, including materials handling. These factors make it imperative to have good test data on the process response of feedstock across the orebody. Collecting that data presents major challenges, which differ for green and brownfields operations. This paper first discusses the approach to preliminary evaluation developed by CRCORE, which relies on testing of coarse rejects or drill chips available from exploration drilling programs. This method is an efficient first step in evaluating an orebody which is deemed geologically to be potentially amenable to screen upgrading, but it does have limitations and must be followed by larger scale work. A suite of methods have been developed by the authors as a result of test work since the 1990s on several projects, supplemented by published data, which aim to provide statistically robust data at lower cost than large scale bulk sampling tests. For greenfields projects, the upgrade response measured on material crushed to -53 mm has been found to correlate closely with ROM ore, with no scale-up required for material with upgrade responses in the range of commercial interest. Large diameter whole drill core, such as PQ, is expected to be suitable for this method. As drilling such core is costly, the aim should be to establish relationships between upgrade performance and proxy measurements such as multi-element chemical or hyperspectral analyses. This approach was successful at the Gramalote gold project in Colombia. The method is not applicable for ores with thick vein material comparable with the crush size, but such material is not suitable for upgrading by screening and would be eliminated by the preliminary testing. For brownfields projects where blasted material can be sampled, the upgrade response can be accurately measured by sampling only the finer fraction of the ore, selecting a top size which represents 30–50 per cent or more of the ROM size distribution. This is likely to be between 50 and 100 mm. The much finer size compared with the full ROM ore greatly reduces the sample mass required to achieve a given intrinsic sampling error and enables sample preparation to be undertaken with large-scale laboratory equipment rather than mobile crushing plant. The accuracy of the method can be improved by measuring the approximate mass of oversize rejected during sampling. Some ores do show a systematic deviation from the assumed model fit which results in this method slightly underestimating the upgrade response, and it would therefore still be recommended to take one or two full bulk samples to confirm results before a final investment decision.

Aug 24, 2022

By C. R. Kerr

"This paper describes the revisions to the heating and ventilating system at the Frood-Stobie mill, which resulted in substantial savings in energy costs.IntroductionInco Metals Company, a unit of Inco Limited, is involved in the mining and processing of nickel-copper ores. The Ontario Division of Inco Metals consists of 10 operating mines, with 5 mines and open pits on a standby basis, and 10 pro- cessing facilities, located in Sudbury, Port Colborne and Shebandowan. In 1980, the Ontario Division's energy expenditures amounted to $87,000,000.Due to the accelerating cost of energy, the Division established an Energy Management Program in 1975 to define, evaluate and implement measures to reduce energy cost and consumption per unit of output by 10% by 1980. This falls in line with the goals set by the mining and metallurgical task force on voluntary energy conservation.To effectively implement the program, Plant Committees were established at each plant and mine area, with an energy management coordinator appointed to coordinate the activities. The Plant Committee's responsibilities include identifying the major areas of energy consumption, isolating areas with large potential losses and determining what action should be taken to improve energy efficiency.Within a five-year period from 1975 to 1980, the Ontario Division has been able to cut its energy consumption by 8.9 trillion BTUs, the equivalent of 1.5 million barrels of oil."

Jan 1, 1981

By Robert L. Clayton, Arthur Baker

Two massive sulfide zinc-copper ore bodies are in quartz-sericite schist (probably formed by regional metamorphism of sediments) and andesite of the Precambrian Yavapai Series, on opposite sides of a large rhyolite mass. The Copper Queen ore body is conformable with bedding of its schist host rock, but the Old Dick ore body probably crosscuts the strata. A lens of low-grade mineralization in chlorite schist, associated with the Old Dick ore body, crosscuts through 150 feet of strata. The ore bodies are almost entirely enclosed by premineral faults with less than 150 feet of displacement. The minerals of the ores are pyrite, sphalerite, and chalcopyrite, with minor arsenopyrite and galena and small amounts of intimately associated chlorite, sericite, and calcite. Old Dick sphalerite-chalcopyrite intergrowths have mutual boundaries, and sphalerite grains contain abundant exsolved chalcopyrite. Copper Queen sphalerite-chalcopyrite intergrowths have extremely ragged boundaries, the sphalerite contains no exsolved chalcopyrite, and the ore overall has a schistose texture. The pre-mineral fault on the hanging wall of the Copper Queen ore body has had 100 feet of post-mineral displacement. Wall rocks of the Old Dick ore body locally have been sericitized. Andesite and quartz-sericite schists for at least several hundred feet around both ore bodies have been chloritized erratically and contain traces of copper.

Jan 1, 1968

By Jimmie C. Rosenbruch

The Federal Bureau of Mines evaluated the prospects for using geothermal energy to generate electricity for mines in remote areas. Given the development of a geothermal resource for this purpose, the subsidiary uses of space heating and agriculture were then examined to see if other industries might be viable given a cheap source of heat energy. Sites investigated were located in three areas of Alaska: Kobuk in the northwest, Unalaska in the southwest, and Stikine River in the southeast. Each site was relatively close to mineral deposits whose prospects for development would be enhanced with cheap power.

Jan 1, 1975