Search Documents

By A. B. Hooker

The flame safety lamp with metal-gauze enclosure was invented by Sir Humphrey Davy more than a century ago, primarily for its safe light; however, it soon became the standard device for detecting the presence of methane in mine atmospheres. It still is the most widely used device for this purpose and is also the most practicable means of detecting deficiency of oxygen in coal mines. A permissible flame safety lamp is similar in all respects to one that, after a series of tests, has been approved by the Bureau of Mines as safe for use in gassy mines. However, safety depends largely upon the way lamps are maintained and used.

Jan 1, 1944

By Celine Y. Zhang, Chloe J. Feng, Charles Q. Jia, Donald W. Kirk

Oil sands petroleum coke (OSPC) is a by-product of coking - a high-temperature process that converts the mined bitumen to the synthetic crude oil (SCO). For every barrel of the SCO produced, about 20 kg of OSPC are generated. Over 70 million metric tons of OSPC have been produced and stockpiled as a result of the development of oil sands industry in the past few decades. Unlike conventional petroleum coke, OSPC has uniquely high impurity contents, particularly sulphur (~ 7 wt%) and metals (e.g. vanadium at ~0.15 wt%), which has hindered its large-scale applications as a solid fuel. Vanadium is a valuable metal that is widely used as an alloy for strengthening steels. The stockpiled OSPC contains about 100,000 tons of vanadium, while the world’s production in 2013 was only 75,600 tons. At the current price of $25US/kg, the OSPC-bound vanadium represents a total value of $2.5 billion US dollars. In this work, we investigate the technical feasibility of extracting vanadium from OSPC. The work focuses on the characterization of vanadium in OSPC and the conditions for effective extraction of vanadium from the OSPC.

Jan 1, 2015

A brief description of the mining method and ventilation system of the San Manuel Mine?s first presented; this is necessary to an understanding of the heat problem and cooling system. The problem of heat at San Manuel is discussed. Charts and graphs showing the relationships between ambient surface air and underground temperature conditions are given. A history of attempts to cool air at San Manuel is presented, starting with the first refrigeration type air coolers which were used in development headings, and followed by the underground water chillers that were used in conjunction with cooling coils. Goals for design of a centralized cooling system with ultimate heat rejection through surface cooling towers are presented. The problems found with using the centralized system in main cooling coils are discussed. Plans for modification of the centralized system as utilized is the summer of 1987 are given, along with results obtained and problems with the system. Plans for subsequent modifications are presented.

Jan 1, 1988

By Maryam Motamed, Jeremy Stone, Leigh Anne Zhang

Controlling and predicting ground movements are essential to the design of shoring systems. The Courthouse Commons tunnel in San Diego, California, included a 56-foot-deep temporary shaft as a launching point for tunneling using the Sequential Excavation Method (SEM). The rectangular shaft was unique in that it was surcharged on one wall by an 11-story building and employed a hybrid support of excavation design. An array of geotechnical instrumentation was used to monitor lateral and vertical movements at the ground surface. This paper compares the measured ground movement with the predicted ground movement from various excavation stages

Dec 1, 2022

By Robert L. Lagace

The purpose of the work reported herein was to investigate whether available telephone multiplexing equipment offered a means to rapidly upgrade the traffic-handling capacity of present mine telephone systems and provide for selective calling for safer and more efficient mine operation. Common sense was used to decide whether or not an item could be termed "available." Since conventional telephone gear is not designed to interface pager phones for example, existing shelf items would require adapters to compatibly interface these two types of gear for independent operation over the present single twisted pair used in mines. These and similar small items were allowed, but if a system required any extensive design work to adapt it for the mines, we ruled it "not available."

Jan 1, 1975

By Alessandro Navarra, Joël P. T. Kapusta

"The converting cost modeling software introduced by Ng et al. in 2005 [1] has been extended to consider the reprocessing of reverts and copper scrap. The original model evaluated the operational costs of a Peirce-Smith converter; algebraic relationships had been implemented with arrays (to represent matrices, vectors and scalar ratios). The new software brings flexibility to the underlying thermochemical balances, by using linked-lists instead of arrays. It is now possible to consider the blending of several feeds, including reverts and scrap.The software computes the length of the converting cycle from the Fe and S content of the charge together with the blowing rate; the times required for other operations (charging, skimming and idle time) are also accounted for. The costs of consumables such as flux, fuel, oxygen or compressed air are all evaluated. Downtime, labor, and materials for converter lining repairs are also considered. The software is easily extended to examine the costs of alternative operating strategies or injection technologies such as sonic single pipe injection and sonic shrouded injection. The potential cost benefits of alternative operating procedures and technologies are discussed through example calculations."

Jan 1, 2009

By Pascual Perazzo Vaschetti Gabriella

The increasing emphasis on environmental issues has crucial importance in mining projects, hence in tailings dams. Their water barrier needs a two-fold environmental assessment: the environmental impact caused by construction activities, and the environmental impact over time. Unfortunately, tailings dams’ failures have great and long-lasting environmental consequences, and as mining sites become bigger and tailings dams higher, the risk of failures may increase. Furthermore, since these dams are mostly constructed over many years, design parameters/materials may change, the engineers may change, and since cost is a driving parameter, less attention may be given to quality control and monitoring. Geomembrane water barriers mitigate such impacts.

Sep 30, 2022

By T Kojovic

"The index A*b, determined from the Julius Kruttschnitt Mineral Research Centre (JKMRC) drop weight tester (DWT) results, has become well-known in the mining industry as a reliable measure of ore hardness in impact or crushing, having the inferred units of t/kWh. This index evolved from a long history of comminution studies at the JKMRC, including the development of the now superseded JKTech twin-pendulum, the industry standard JK Drop Weight Tester (JKDWT) and the faster alterative JKMRC rotary breakage tester (JKRBT). A reduced version of the DWT, the semi-autogenous grinding mill comminution test (SMC test®), also provides estimates of the A*b though the testing of only one particle size at five specific energies. Experimental determination of A*b using the above devices/tests requires samples, with sufficient mass, to be sent to designated laboratories, registered to conduct such tests. This protocol is fine for bankable and commercial testing, where material characterisation data is used in conjunction with machine specific data in modelling and simulation, and power based calculations. However, for comparative testing, where results are required at the time of sampling (eg for plant troubleshooting or spot-surveys), or for rapid ranking of geometallurgical samples, these existing tests simply do not provide a timely, viable and cost-effective solution. In order to address this critical void in the realm of comparative testing, a new device has been developed, exploiting a central feature of single particle impact testing – that the A*b can be reliably estimated using one precise low energy test. This device, for which a patent is currently pending, called the HIT (Hardness Index Tester), has been precision engineered to allow users to break narrowly sized fragments at a set specific energy, in a safe and easy manner. The manufacturing materials have been chosen carefully to ensure compatibility with the intended use and portability to any site, whilst minimising cost. The device is supplied with a novel quality assurance / quality control (QA/QC) feature, to ensure that the targeted potential energy is consistently delivered. The product from the HIT breakage test can be quickly sized using a single screen to determine the mass per cent undersize, from which the A*b index is calculated directly at site – eliminating the need to send the raw data off-site for analysis. On presized fragments, a single test using 20 fragments takes less than five minutes to complete, and the results are immediately available. The HIT is currently being tested at a major mining laboratory in the US and the results to date have proved it can deliver on all fronts. This paper describes the new prototype device, which offers users a low cost in-house mechanism for estimating the A*b at any mine site, with potential applications on fragments up to 25 mm from drill core, blast chip rejects or the grinding circuit feed. It also outlines the results of field tests carried out by an objective third party mining group and compares the results with those from current industry standard tests conducted on the same material.Citation:Kojovic, T, 2016. HIT - a Portable Field Device for Rapid Testing at Site, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 9–16 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By J. B. Carman

This paper, describing the mining practices and methods at the mine of the Molyb¬denum Corporation of America, is one of a series of similar papers on mining methods in the various mines of the United States being prepared by the Bureau of Mines. The mine of the Molybdenum Corporation of America is in the Red River mining dis¬trict, Taos County, northern New Mexico (fig. 1), The mill and camp are in the valley of Red River, about 7 miles east of the town of Questa; the mine is 1 ¼ miles away, in Sulphur Gulch, a tributary of Red River. The mine is about 600 feet higher than the mill, at an altitude of about 8,700 feet. The climate is cold in winter, but does not interfere serious¬ly with continuous operation. The mine normally produces about 40 tons of sulphide molybde¬num ore per day, which is concentrated at the local mill and chipped to the plant of the Molybdenum Corporation at Washington, Pa.; there it is made into either ferromelybdenum or "molyte" (calcium molybdate), for use in alloys. The ore is mined from narrow, irregular veins by the cut-and-fill method. About 65 men are normally employed underground and on the surface at the mine.

Jan 1, 1931

By G. J. Heferen, A. Pranowo, N. J. Aslin, P. O. Eriksson

Glencore Technology (GT) has over four decades experience supplying stainless steel cathode plates (“cathode plates”) to the electro-refining and electro-winning industry. Cathode plates are typically the single biggest capital investment in a refinery. Refineries may view cathode plates as fixed asset or consumables depending on their operational characteristics. This paper examines the issue of cathode plate life and the strategies and philosophies used by different plants in the management of their cathode plate asset. Some plants operate with their original plates after more than 20 years. Others accept high turnover and regular maintenance as normal operating practice. Reference data are provided on plate life for various operating plants including benchmark plants achieving best-practice plate life and operating cost. The role of the electrode handling equipment on cathode plate longevity is also examined, including latest developments in Cathode Stripping Machine, robotic copper stripping, and full-automation production cranes. The ability to identify and manage the population of plates in service is also critical for maximising plate life and minimising its overall operating cost. This paper discusses a novel and unique RFID system for tracking and managing cathode plate inventory. INTRODUCTION Permanent cathode plates The adoption of permanent stainless steel cathode electrodes in the electro-refining of copper was the most significant process development since the first commercial electro-refineries were built in the late 19th century. It provided significant improvement over the labour intensive and complicated starter sheet system. Copper grows over the permanent cathode blade for a number of days before being stripped, and the permanent cathode can be returned straight back to cells for the next cathode cycle. Glencore Technology (formerly Mount Isa Mines (MIM), then Xstrata Technology) has been manufacturing permanent stainless steel cathode plates from the late 1970s with the birth of ISA PROCESS™, and the Kidd process that came one decade later. Invented and commercialised by Mount Isa Mines, the ISA PROCESS™ was first implemented into Copper Refineries Limited (CRL), Townsville, in 1978. The KIDD PROCESS by Falconbridge evolved in the 1980s and was first implemented into the Kidd Creek Tankhouse, both operations converting from traditional copper starter sheets.

Jan 1, 2019

By Oliver Bowles

From the most remote periods of civilization stone has been used to perpetuate the memory of individuals or to immortalize their noble achievements. Ancient memorials ranged from simple piles of stone (cairns), or single markers, to great obelisks and pyramids or magnificent mausoleums. The Taj Mahal at Agra, India, built of white marble by Shah Jehan in memory of the Empress Mumtaz Mahal, is one of the most beautiful and costly memorials ever built. It was erected between 1632 and 1650 at an estimated cost of $50,000,000 or more and is today an object of unusual interest for travelers. Other magnificent memorials both ancient and modern are to be found in many lands. No sharp line can be drawn between buildings and monuments, because the larger types of memorials such as the Bok Singing Tower, Lincoln and Jefferson Memorials, and mausoleums of various types have features in common with buildings. However, great care must be exercised in selecting a site for a quarry that will produce acceptable monumental stone because appearance as well as quality is of prime importance. The deposit must be of uniform texture and attractive color and must be notably free of knots, hairlines, impurities, incipient seams, or other defects. Many memorials are of polished stone, and spots or streaks that might be virtually Invisible on a natural rock face will appear distinctly on a polished surface. Hence, stone to be polished must be selected with unusual care. However, less flawless stone may be used for hammered surfaces.

Jan 1, 1955

By R. A. Beall

This paper summarizes the development of a furnace for producing titanium castings. The general problem is outlined and chronological details are given on the construction and operation of four different casting furnaces, all utilizing consumable-electrode arc heating and water-cooled copper crucibles. Of the two methods of pouring, the tilt-pour technique has been more satisfactory than bottom tapping. Mold design, electrode fabrication, and deep-pool production are discussed. INTRODUCTION In the early summer of 1953 the Bureau of Mines was contacted by the Department of the Army through Watertown Arsenal to explore the possibility of conducting research on casting titanium metal. The objective of the program was "to develop a technique for producing formed castings of titanium metal not less than 40 pounds in weight and without introduction of deleterious contamination."

Jan 1, 1956

By Roscoe W. Stensrud

Marcona Mining Company operations are located 500 kilometers south of Lima, Peru, on the Pacific Coast, at approximately 15º-22' latitude south and 75º-11' longitude west. The terrain is sandy rolling hills ranging from sea level at the coast and rising sharply (escarpment) to an elevation of 800 meters at the mine area. The climate is arid and windy with a moderate year-round temperature, ideal for a year-round mining operation. San Juan, a new and modern community of 14,000 inhabitants and developed by Marcona, houses the working forces and their families.

Jan 11, 1968

By C. Carrasco

Caletones Smelter, Division El Teniente of Codelco Chile, has used Teniente Converter (TC) as the only smelting unit since November 2000. The modernization project considered the shutdown of the last reverberatory furnace, the installation of the fourth Teniente Slag Cleaning Furnace, the installation of a new fluidized bed dryer and the modification of the concentrate injection system into TC. The modernization project and related investments allowed for the increase of the smelting capacity up to 1.25 million t of concentrate annually.Next stage of the smelter expansion in the year 2004 considered the increase of the smelting capacity up to 1.44 million t/year. The expansion required technology modernization and the installation of the new equipment, such as concentrate injection system, oxygen plant, fluidized bed dryer and storage bin. Currently the annual smelting capacity is about 1.35 million t of copper concentrate, being limited by sulphuric acid plant treatment capacity. This paper presents the technology and production evolution in the Caletones Smelter in the years 2000 - 2006, demonstrating the potential of development and competitiveness of Teniente Converter as world-wide recognized smelting/converting reactor.

Jan 1, 2007

By Lyman Moore

This Bureau of Mines report describes 2nd evaluates iron ore resources in California and Nevada and analyzes the California and Japanese iron ore markets in which these resources will be used. The competitive position of California-Nevada ores, in these markets, was estimated by comparing regional iron ore prices, production costs, and transportation costs with those of foreign suppliers. Resources were determined to be sufficient to produce the equivalent of 585 million tons of 64-percent iron pellets at a price of less than $15 per ton delivered at California ports. Much higher tonnage could be produced at higher prices. Iron ore requirement of the California iron and steel industry will increase to an estimated 15.9 million tons by the year 2000. A study of the iron ore production potential of California-Nevada deposits and of out-of- State sources indicated that this ore requirement can be supplied most economically by California-Nevada ores. Iron ore import requirements of the Japanese iron and steel industry will increase to an estimated 150.0 million tons by the year 2000. A study of price trends in this market indicated that very little California-Nevada iron ore will be sold in Japan after 1973 when existing sales contracts expire. Iron ore-exports might be economically possible if ore could be transported from California to Japan at ballast rates as backhaul on existing petroleum shipping.

Jan 1, 1971

By Paris V. Brough

This paper, which describes the practice of milling custom ore, in addition to that produced under company and lease operations in the Tom Reed mines, is one of a series 'being prepared by the Bureau of Mines. ACKNOWLEDGMENT Acknowledgment is made to W. B. Phelps, managing director, and Jack Zwinge, superintendent, far permission to publish, a-ad to G. E. Jarpe, the present mill superintendent, for his assistance in preparing the paper. LOCATION The mill is in Oatman, adjacent to the Benjamin Harrison shaft of the Tom Reed Gold Mines Co., in the foothills on the western slope of the Black Mountains, western Mohave County. The railroad shipping point is Kingman, Ariz., 25 miles northeast of Oatman. Paved highway U. S. 66 passes by the mill. The altitude is approximately 2,700 feet.

Jan 1, 1937

By Charles A. Lindberg

Mobile cranes on tires are perhaps the most important accessory in truck-haulage pits. They usually are of 20-ton capacity at short radius and with outriggers but have considerable overload capacity. Standard booms are 30 ft but have 10-ft extensions with which they are usually operated. Cranes have two engines, both originally gasoline, but 150-hp Diesel engines have been found more reliable for the propulsion motor, the 100-hp gasoline motors being retained for hoisting. Pro- visions are made for dropping the ballast counter- weight to reduce axle weights to legal limits for highway travel. The weights are carried on a regular truck or are transported on an extra trailer axle behind the crane. Tractors-Probably equalling the cranes in usefulness are the track-laying tractors which are used to prepare roads and other surfaces, to clean up at the shovel, and for dozing on stripping dumps. A new type of tractor mounted on rubber tires has been tried out on the Mesabi Range for the past year and a half. The advantage of this design is its mobility which makes it capable of taking care of the spill at the shovel and then running to the dump to clean up. Alternating between these two jobs, it relieves heavy tractors that can be used to better advantage on heavier work that does not require so much traveling. This tractor can travel at speeds of 12 to 13 mph and is designed to facilitate repair of the expendable parts. Weaknesses have developed in the internal construction which have seriously marred the performance record of this unit, but when used within its capacity it is quite successful.

Jan 1, 1949

By BARONJUPTNER VON JONSTORFF, Andrew A. Blair, GUNNAR DILLNER

IT is a well-known fact that the results of different analysts, when operating on the same identical sample of steel or iron, are far from concordant, and it not infrequently happens that great annoyance and trouble in the commercial community are occasioned by these discrepancies. Attempts have been made at various times to investigate the causes of such differences and to obtain more reliable methods of analysis. The most important of these was made by the British Association in 1889: The following gentlemen, with Sir W. Roberts-Austen as Chairman, and Professor T. Turner as Secretary, were constituted as a committee to investigate the question, viz.: Sir F. A. Abel, Mr. Edward Riley, Mr. G. J. Snelus, Mr. John Spiller, Professor J. W. Langley, and Professor Tilden. Average .samples of steel were prepared in America under the superintendence of Professor J. W. Langley. The steels, in the form of turnings, were divided and distributed to sub-committees in Great Britain, America, France, Germany, and Sweden. In Sweden Professor Åkerman acted as Secretary to the Swedish committee. The Government Department of Tests was appointed in Germany; Mr. Ferd. Gautier in France; the British Association Committee in England; Messrs. William

Mar 1, 1905

By Ferdinand Roehlich

An evaluation of the use of manually activated, installed,. dry chemical fire protection systems on underground metal and nonmetal mine vehicles is described. In addition, an assessment of the possible health risks posed by the dry chemical extinguishing agents used in such systems is provided. Work involved installation of fire protection hardware on an operating piece of underground metal/nonmetal mine equipment and, via actual fire tests, a determination of the effectiveness of the hardware in extinguishing on-vehicle fires. Two fire protection systems were installed on a Caterpillar 988 front-end loader in St. Joe Mineral's Fletcher mine, near Viburnum, Mo. Both a fully pressurized Safety First CM-20 and a nonpressurized cartridge actuated Ansul A-101 were installed for comparative purposes. Both systems operated satisfactorily during an 8-month endurance trial period which preceded the actual fire tests. Each system was able to extinguish an 18" x 4" class B test fire placed in the engine area of the machine. The health hazards analysis of dry chemical powder consisted of a detailed search of published literature relating to these multipurpose agents. This data was verified via a controlled laboratory analysis of two monoammonium phosphate based powders (Safety First Unikem and Ansul Forey) and an analysis of air samples collected at various locations on the test vehicle during the fire tests. Although the powder was found to be nontoxic, two potentially dangerous thermal decomposition products were identified--ammonia and phosphoric acid. However, later analysis indicated that an operator would not be exposed to dangerous concentrations of either compound if he were to remain outside of the powder cloud. A "Selection and Use Manual for Manually Activated, Fixed Fire Suppression Systems on Underground Metal and Nonmetal Mining Equipment" was prepared both as an, appendix to the report and for distribution under separate cover.

Jan 1, 1977

By J. G. Eacott

This paper reviews the role of oxygen potential and the advances that have been made in the application of tonnage oxygen in copper smelting. Brief reference is made to reaction kinetics before attention is turned to the thermodynamic considerations in copper melting to illustrate the importance of oxygen and. oxygen potential in the component parts of the overall smelting process. The chemical potential diagram for the Cu-Fe-S-O-Si02 system is used to elucidate the difference b etween the conventional matte smelting process and the modern continuous processes. A progressive oxidation scale' is constructed to show the common elements which exist, and the matte grades produced, during the smelting of concentrates to blister copper in commercially available copper smelting processes and those under development. The common route in producing blister copper from molten mattes, regardless of process, is illustrated on the Cu-Fe-S equilibrium phase diagram. The essential features of oxygen enrichment, in terms of its effect on combustion conditions (i.e. oxidation of fuel and sulphide minerals) and the heat balance are outlined. The benefits of oxygen enrichment are listed. The influence of tonnage oxygen and its effect on productivity, fuel savings, gas volume and strength in various copper melting processes are examined as a state-of-the-art review. Reference is made to the economics of tonnage oxygen utilization.

Jan 1, 1983