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By H. J. McQueen

Mineral and energy resource consumption were continuously reduced by process improvements as chemical understanding was developed and applied. During the past two centuries, technological improvements increased human productivity that was accompanied by social advances and labour saving products; however, these sometimes proliferated to endanger sustainability, e.g., automobiles. In the steel industry, precisely controlled rolling of HSLA steels required little extra mineral consumption but reduced weight and heat-treating energy. Continuous casting of slabs reduced scrap compared to ingots and energy for the homogenizing soaking pit. Al alloy extrusions were improved by retaining the strengthening in the near-surface substructure, of high strength textures and of press quenching that is suitable for direct age hardening. Continuous bar casting of Al-0.65Fe, coupled with rod rolling and followed by wire drawing with only a final recovery anneal, yielded electrical wiring for households to replace less plentiful Cu and later for light-weighting use in autos and aircraft Looking backwards, the 1970 decade saw the first oil crisis and inspired Ottawa to undertake a campaign to develop an energy strategy that would decrease dependence on imported fuels. One significant undertaking under Energy Mines and Resources was the organization of industrial energy conservation, managed by each industry association,that collected detailed current statistics and set the goals for a 2-year campaign. The metal producing industries, as compared by E.C.N. Perryman to about 7.2 exajoules (EJ) for the nation, consumed about 0.8 EJ, being about one third of all heavy industries. While manufacturing consumed 30.2% of total energy, it created 87.3% of total national dollar value. Within the industrial envelope, smelting and refining utilized 28% (0.67 EJ, mining beneficiation 6.7%, 0.16 EJ); there was a significant contribution to exports: 80% of iron ore and 70% of aluminium in 1973. A general concern was that decreases in ore grade would lead to a rise in energy expenditures countering benefits from processing efficiency.

Jan 1, 2012

By A. Bhagwat, S. Tadolini

"Steel members of the ground support systems in underground mines are routinely exposed to corrosive environment that may range from acidic to alkaline. Corrosion of steel bolts leads to metal loss and thereby, reduction in strength and useful life. Protective coatings are commonly applied to the steel bolts to combat corrosion. However, coatings are expensive and often cumbersome in practical applications. Instead, Minova has developed an innovative technology based on sacrificial anodes. The anodes were designed from non-ferritic alloys that are inferior to steel on the Galvanic Series. This paper will present data from field testing to show significant benefit of the technology. Potential applications in current products will be discussed. INTRODUCTION Corrosion is a physical alteration of a steel material from electrochemical reaction with its environment that often results in reduction of the mechanical and physical properties of that material. Mine roof bolts, the subject of this investigation, are particularly susceptible to corrosion as they can be exposed in their working environment to ground water and air with high humidity. As other researchers have determined, corrosion increases markedly in sulfide ore bodies due to acid runoff. There are several types of corrosion that a rock bolt is likely to undergo when used for ground reinforcement in underground mines (Aziz et al., 2013). Of all the types of corrosion, pitting is particularly dangerous as it can remove capacity for the bolt to deform with subsequent strata movements. Sudden failure of a bolt is likely to occur when severe pitting corrosion is experienced. The type and nature of corrosion depend on the nature of the ground condition and bolt encapsulation. Generally, the type of corrosion and severity of the corrosion varies along the axis of bolt. Almost all of the mine roof bolts used in mines, with the exception of fiber reinforced polymers, are made from steel. The corrosion of iron is an electrochemical phenomenon with the overall equation:"

Jan 1, 2018

By C. Green, J. Uhrie, C. Filippone, A. Guzman

A central aspect of heap leach management and recovery optimization is solution control. Insofar as each heap is unique in physical and metallurgical properties, it is essential to understand the hydraulic parameters that control the migration of solution on a case-by-case basis. Water Management Consultants, as part of an ongoing research effort for Phelps Dodge Process Technology Center, have adapted techniques of parameter estimation for application to data typically resulting from metallurgical column testing. The parameterization is completed within the context of a variably saturated flow model that allows interpretation of available hydraulic information collected during hydrometallurgical column tests. A novel interpretation approach is introduced to extract the necessary hydrodynamic parameters from typical hydrometallurgical data sets. Results from the application of the approach to standard metallurgical test data will be presented together with a discussion of the application of information gained to the design and operation of a heap.

Jan 1, 2002

By A. D. Davis, C. J. Webb, C. S. Johnson

The Belle Eldridge Mine is an inactive lead-zinc mine in Spruce Gulch south of Deadwood, South Dakota. Acidic mine drainage (AMD) produced at the site drains into Spruce Creek, a tributary of Whitewood Creek. The site is on U.S. Bureau of Land Management (BLM) property. Extensive fieldwork was done at the Belle Eldridge Mine through the cooperation of the BLM and the South Dakota School of Mines and Technology. The site was extensively mapped to identify physical and environmental hazards such as tailings, waste rock, collapsed buildings, adits and workings. An exhaustive search of the historical records of the Belle Eldridge Mine was conducted. Maps of the under-ground workings of the Belle Eldridge dating from the 1930’s and 1940’s were found. The maps were used to correlate currently collapsed features to old adits and tunnels. Using hand corers and a portable drill rig, waste rock, tailings and soil core samples were collected and depth to bedrock was determined and the total volume of waste and tailings pile were determined. Related work examined the hydrology of the site. The site is very complex hydrogeologically. Numerous underground and surface workings and tunnels add to the complexity. Several seeps are located at the site, one of which is producing AMD. Recharge to the site was studied, and a 100-year flood plain map was produced.

Jan 1, 2000

By D M. Aranha, M A. Fonseca, M Echtern

The regional syndeformational metamorphism affecting the Itabira Iron Formation (IIF) at Quadrilßtero Ferrffero (QF) was formerly discussed by Dorr (1965), who proposed that quartz grain size could monitor the metamorphism, according to James (1955), and that the formation of haematite could be the result of the synchronous metasomatic process. Herz (1979) suggested the existence of three metamorphic zones, not mentioning the haematite formation. It could be observed that the primary oxide phase in the IIF is magnetite and most of the hard haematite was derived from the metamorphic replacement of magnetite, forming micaceous or schistose haematite. Differently from most iron formations in the world, the formation of haematite deposits at QF occurred under high oxygen fugacity during metamorphism. The haematite microlaths display a strong preferred orientation, which determines the alongated shapes of the fragments. The terms foliated and unfoliated haematite have been applied by Dorr to the micaceous or schistose haematite, and to the isotropic, hydrothermally derived haematite. Under the microcope, the haematite exhibits a strong crystallographic or lattice orientation encircling the magnetite and martite porphyroclasts. The strain rate determined and defined the textural variation, size and economic importance of the deposits and the ore grade. Metamorphism at QF increases eastward and resulted in the formation of a gruneritic Fe-Mg amphibole, at the western portion, followed by a cummingtonitic amphibole at the central-western part, succeeded by the actinolite zone at the central-eastern part, and finally to the tremolite-anthophyllite zone to the east. These zones, arranged in a north-south pattern, can be followed in the pelitic units, whereas appear sericite-chlorite, kyanite-chloritoid and garnet-staurolite respectively. Carbonate geothermometry in IIF also may support the metamorphic variations. At the western zone the haematite forms small lenses within the itabirite, P-contents are slightly higher than in the remaining IIF, haematite grain size is minute, resulting in a submicaceous texture and the amount and dimension of relict magnetite within haematite is greater than in the other parts of QF. Jangada and Serra Azul deposits are examples of this zone. The central-western zone is characterised by significant haematite deposits, in considerable quantity and size, haematite grain size increased, in order to produce a micaceous texture, the P-contents and the amount of magnetite decreased. Pico do Itabirito, Cappo Xavier, Capitpo do Mato and Tamanduß correspond to the deposit type of this zone. At the eastern-central portion the amount of the hard haematite deposits decreases, increasing the soft haematite ore due to higher strain rates. However, it can be perceived that the relict magnetite almost disappeared and the haematite grain size became coarser than the haematite from the western zones. At the eastern zone, the haematite deposits exhibit typical schistose texture, the magnetite porphyroclasts are absent and the lowest P-grades in the haematitic iron formation. The haematite bodies characteristic from this zone are Andrade, Morro Agudo and the deposits at the Itabira District. The hydrothermally derived compact and isotropic haematite deposits, formed subsequently to the micaceous haematite bodies, were generated after deformation ceased, but under very high fluid pressure. The metamorphic reactions magnetite + quartz + H2O = grunerite + haematite and magnetite + quartz + H2O = grunerite + O2 were decisive in the formation of the metamorphic haematite deposits.

Jan 1, 2007

By Qingwen Shi, Brijes Mishra

Laminated rock can delaminate and fail under certain stress states. Delamination-caused roof fall and cutter roof failure is a common failure mechanism in roadways in Pittsburgh coal seam due to the existence of laminated shale roof. Two-dimensional numerical models were developed at laboratory scale based on the bonded particle method in order to simulate the delamination with particle flow code. In these models, an assembly of bonded particles and parallel weak planes represents the laminated rock. This model calibrated the micro-parameters of the bonded particlematerial and weak planes with laboratory data. The mechanism of fracturing and delamination in a laminated specimen was investigated using unconfined and confined compression test and unsupported roof compression test. The numerical results show that, under a constant horizontal stress, delamination occurswhen the stress is much lower than its compressive strength. The confined compressive test indicates that delamination is restrained by applying confining stress since delamination-caused failure does not occur during any stage of the confined compressive test. Unsupported roof compression tests showed propagation of cutter roof failure with initiation of cracks and delamination at the intersections of the roof and ribs. An outer failed zone and inner failed zone form separately. The separated zones connect and form an opening in the roof. The presented numerical results provide additional insight into process of delamination.

Sep 14, 2020

By S. F. Shaw

MINING conditions in Mexico during the current year have been most unfavorable, synchronizing with conditions in the United States, but the outlook for the near future is improving. The chief difficulties met with are because of the following conditions: severe drop in prices of metals; high smelting rates; high prices of supplies; inadequate means of transportation; low efficiency of labor. In comparison with pre-war prices for metals it cannot be said that prices are low, particularly for silver, which recently has gone to a level that would have been considered exceedingly good in 1912. But conditions have changed so greatly that only the most favorably situated properties can operate without loss.

Jan 1, 1921

By A. B. Needham

This report describes the exploration work done in 1941 in connection with the search for strategic minerals as authorized by the Strategic Materials Act approved by the President on June 7, 1939. It deals with the various manganese deposits and showings in the Tombstone mining district of Cochise County, Ariz. The exploration project comprised a study of the geology, mapping of the areas, and exploration of various mines and deposits by sampling old drifts, crosscuts, and scopes, supplemented by diamond drilling from underground stations. The Federal Government's manganese-purchasing programs have revived interest in occurrences such as the scattered deposits near Tombstone. Because of this, the Bureau of Mines project report on the Tombstone district, prepared originally in 1941 but not published, has been revised and now is being made public.

Jan 1, 1956

By Peter G. Kovalchik, Rudy J. Matetic, Susan B. Bealko, Adam K. Smith

Overexposure to noise remains a widespread and serious health hazard in the U.S. service providing and goods producing industries. Excessive noise can lead to poor verbal communication and reduce the ability to recognize warning signals. These dangerous work conditions can also cause stress and fatigue. Occupational hearing loss is a permanent illness, with no recovery currently possible. Method: National Institute for Occupational Safety and Health (NIOSH) has recognized Noise Induced Hearing Loss (NIHL) as one of the ten leading work related diseases and injuries in the United States, and has emphasized its importance as one of the critical areas expressed in the National Occupational Research Agenda. Results: One of the most serious noise problems in the goods producing industries is the operation of continuous mining machines during underground coal mining. In order to minimize occupational hearing loss, noise hazards are “designed out” early in the design process. NIOSH is leading a national initiative called Prevention through Design (PTD) to promote this concept. This paper describes the quiet by design approach of a noise control that reduced noise exposures of continuous mining machine operators by 3dB(A) using the four functional areas of PTD, namely Practice, Policy, Research, and Education.

By G. A. Brady

Seven samples of Pennsylvania anthracite from the Bottom Ross bed were analyzed and tested to obtain data on cleaning characteristics, proximate and ultimate analyses, specific gravity, grindability, heating value, and ash softening temperature. Ash content of the samples varied irregularly from 9.0 to 34.4 percent, the range being narrowed to an upper limit of 14.8 percent ash by removing impurities dense enough to sink in a medium with a specific gravity of 1.90. Ash content of the sink material with specific gravity greater than 1.90 ranged from 56.4 to 80.4 percent; corresponding specific gravities were 2.095 to 2.534. Volatile matter contents were indicated to be higher for the ash-forming minerals than for the pure coal substance in the various specific gravity fractions of a given sample. Specific gravities of anthracites with compa¬rable ash contents but from different locations in the bed varied as much as 0.06. The grindability index increased significantly with increasing ash con¬tent of specific gravity fractions from all the samples.

Jan 1, 1968

By P. Huang, D. W. Fuerstenau

Various factors that control the natural flotability of talc, including differences due to crystal face and edge effects, were delineated. For study of talc depression phenomena, dextrin was used as a model depressant. For the enhancement of talc flotation, dodecylammonium acetate (DDAA) was used as the collector. The interaction of DDAA with talc was assessed by flotation experiments and electrokinetic (zeta potential) measurements, from which the role of hydrophobic bonding can be demonstrated. The results presented in this paper provide useful information on how the crystal chemistry and surface chemistry control the electrical double layer, adsorption phenomena, wettability, and flotation behavior of talc in aqueous media.

Jan 1, 2003

By Thomas W. Mitcham

NUMEROUS ore deposits remain to be discovered. Many exposures of favorable host rock bodies within mineral provinces have not been adequately scrutinized geologically-the ore potential in buried portions of such rock bodies is enormous. Inasmuch as the more obvious deposits have been found, exploration has become more scientific and more expensive. Yet discovery continues to be very rewarding if exploration is intelligently approached. Although a number of exceptions can be cited, systematic geological exploration for ore on a significant scale has developed during the last two decades. So rapid has been the development of systematic exploration that a comparison of modern programs with those as recent as 1940, would suggest that many large mining companies and various Government agencies were hardly in the exploration business at that time. What is modern ore exploration? What major factors affect its success-economic discovery?

Jan 2, 1955

By Michael J. Jorgensen, Anoop Polsani, Khurram S. Khan

Riveting operations in aircraft manufacturing involves the use of power tools for manually drilling holes for the rivets, power drills for the setting of the holes for the rivets, as well as rivet guns to drive and set the rivets. To close the rivet, the rivet is driven against a metallic bar commonly called a “bucking bar”. The bucking bars are typically held firmly to increase the quality of the riveting, as well as keep the bucking bar from “dancing” against the metal piece being riveted. Thus, employees in aircraft manufacturing involved in riveting are exposed to hand-arm vibration from several sources, and epidemiological evidence suggests that vibration-related musculoskeletal disorders are associated with long term exposure to riveting tasks in the aircraft manufacturing of aircraft.1,2 Recently, tungsten technology has been introduced into aircraft manufacturing for bucking bars, which are heavier than traditional steel bucking bars of the same size. Rivet guns with tungsten pistons instead of steel pistons have also recently been introduced with the objective of reducing vibration exposure to the riveter. The objective of this study was to assess vibration characteristics of steel and tungsten bucking bars and rivet guns to identify the combination that simultaneously reduced the combined exposure to both the “riveter” and “bucker”. Methods Vibration (10g tri-axial accelerometer, Biometrics S2-10G-MF Series 2) was measured from eight experienced employees using seven different rivet guns on size 6 rivets, with the same person bucking for all subjects. Vibration was also measured on two different bucking bars for these same eight subjects, with the same person driving the rivets using the various rivet guns. The rivet guns consisted of three E4 steel piston guns with different RPMs (Guns A-E4, B-E4, C-E4), an E4 vibration dampened rivet gun (Gun D-E4D), an E3 steel piston rivet gun (Gun E-E3) and an E3 and E4 tungsten piston rivet guns (Guns F-E3T and G-E4T). The bucking bars were made of 90% tungsten (1694g) and cold-rolled steel (843g), and were the same shape and size. A two-way repeated measures analysis of variance was performed on the vibration (mean frequency weighted resultant acceleration) on both the rivet gun side and the bucking bar side, and mean rankings were used to assess the vibration simultaneously for the rivet gun and bucking bars to investigate which combinations provided the lowest vibration exposure. Results Frequency weighted resultant acceleration was significantly lower on the E3 tungsten (F-E3T) rivet gun than the E4 steel piston (B-E4) and the E4 tungsten piston (G-E4T) rivet guns (Figure 1). When measuring vibration on the bucking bar, the E4 (A-E4) steel piston rivet gun resulted in lower vibration on the bucking bars than the E4 tungsten piston (G-E4T) and E4 vibration dampened (D-E4D) rivet guns (Figure 2). Additionally, use of tungsten bucking bars resulted in a 35% decrease in resultant frequency weighted acceleration than when using steel bucking bars.

Jan 6, 2006

By Carl Sunderman, Steve Signer

Researchers at the National Institute for Occupational Safety and Health (NIOSH) have developed several new tools for evaluating roof support performance. A miniature data acquisition system (MIDAS) was developed that can collect readings from up to 16 strain gauges at regular time intervals and store the readings for later retrieval. Three LED lights change from green to yellow, then red, based on the reading levels and/or rates of change of rock movement. This feature can be used to warn miners of rock instabilities. The system can be used with any strain-gauged support (resin bolt, friction bolt, cable bolt) or with a newly developed rock strain strip (ROSS) developed by NIOSH to measure rock strain. A ROSS is grouted in a hole drilled adjacent to the rock support to be evaluated; the deformed shape of the ROSS provides anchorage on either side of the strain gauges. Data from both laboratory tests and field evaluations are presented that describe the capabilities of both the MIDAS and ROSS instruments.

By A. G. Ballachey

Introduction This paper will describe the mining plant and underground operations at Quemont. Details of geology and milling are beyond its scope. Papers on these subjects will be prepared and presented separately. A detailed account of the exploration and development, 1944 to 1947, has been given by W. L. Brown (1). Location The mining concessions of Quemont Mining Corporation, Limited, are in Rouyn township, Rouyn-Noranda county, northwestern Quebec. These concessions total about 640 acres in area. They lie within the limits of the City of Noranda, contiguous to, and directly north of, the Horne mine of Noranda Mines, Limited. A large area in the southern part of the property is covered by the north arm of Osisko lake. Production The present operating rate is about 2,100 tons per day. Three flotation concentrates are produced: copper, containing a large proportion of the gold and silver in the ore; zinc; and pyrite, which carries an appreciable additional proportion of gold. The copper and zinc concentrates are shipped to smelters as produced. The pyrite concentrate is cyanided to recover additional gold, after which it is filtered, dried, and shipped for the manufacture of sulphuric acid. The principal revenue metals are copper, gold, and zinc. Silver and pyrite are important by-products.

Jan 1, 1952

By Jos. Kalbhenn

PART of the plan of re-allocation evolved by the engineers of the Dominion Steel and Coal Corporation in 1932 to retard the rapid advance of the submarine workings seawards was the opening of Dominion No. 20 Colliery, in the Harbour seam, by a pair of cross-measure tunnels from the workings of an older mine working the Phelan seam, which lies 430 feet below the Harbour seam. The tunnels, 8 ft. by 13 ft. in size, were started away from the old workings of Dominion No. 2 at a point 1.5 miles beyond the shore line and were driven on a rising grade of 1 per cent for a distance of 5,335 feet, tapping the Harbour seam at a point 2 ¼ miles off-shore. For transportation and ventilation, shafts and roadways already existing in the Phelan seam were made use of during the stages of development and up to the present time. One of the two tunnels served as a main haulage road and an intake airway, and the other as a return airway and travelling road. However, as the workings of this new colliery expanded, the need for additional airways arose as was anticipated when the plans for the development were formulated. To meet this need, work was started on October 1st, 1942, to establish a new opening between Nos. 2 and 20 Collieries in the form of a vertical shaft to provide a passageway for the ventilating air current of some 250,000 cubic feet per minute on its return to the upcast shafts in No. 2 Colliery, thus making both tunnels available for intake airways. In the interest of safety, speed, and economy, the shaft was raised from the Phelan to the Harbour seam. It is 20 ft. by 12 ft. in size and, with the exception of three timbered compartments across the narrow end, is untimbered. One of the three timbered compartments housed the ventilating tubing and pipe lines, the centre one served as a cage-way for hoisting men and material during the operation of raising, and the third one contained a ladder way. The rest of the shaft was filled with debris during the period of shaft raising.

Jan 1, 1944

By Gary E. McIntosh

This paper will discuss a US Bureau of Mines project designed to assess and predict the impacts which surface coal mining will have on the regional shallow groundwater system in the Powder River Basin. The primary objective will be met through the accomplishment of the following: (1) The design and establishment of a regional network for monitoring shallow groundwater systems in the basin; (2) monitoring the direction and rate of flow, water quality, and aquifer characteristics of the shallow groundwater systems; and (3) development of a regional groundwater simulation model, with appurtenant subroutines to determine local effects.

Jan 4, 1979

By Wei Yun-Jie

Columnar jointed basalt is a fractured rock, with a lot of small spacing structural planes and poor integrity of the rock mass. On the basis of the comprehensive study of the columnar shape of Columnar joints, rugosity of the fracture surface and the chemical composition of basalt, columnar joints of Bai hetan dam area were formed as a result of the cooling and shrinkage effect of magma. Columnar joints basalt are mainly chlorite, kaolinite, epidote, tremolite chemical reactions and the content of columnar joints are mainly chlorite by slice identification and chemical analysis. Columnar joints basalt showed high uniaxial tension test, low coefficient of friction and high cohesion by indoor physical and mechanical test. Columnar joints rock mass showed high strength and large deformation by field shear test and deformation test. Columnar joints basalt can be used directly as a foundation of dam as long as we follow the rules and reduce disturbance strictly.

May 1, 2009

By Roy F. Waters

An inventory was made by the Bureau of Mines of wastes of mineral origin, water requirements, treatment of wastes, and water treatment practice of 163 industrial installations in the Lower Missouri River Basin. This is the second and concluding report on the survey, conducted in cooperation with the Missouri Basin Field Committee of the Department of the Interior as part of the Missouri Basin project. Principal industries covered by this second report are: Sand and gravel, coal, meat, ice, brewing, paint, petroleum, chemical, fabricated metals, and a number of industries having either no waterborne wastes, or none of mineral origin. Gravel, sand, and silt from 47 producers are the major wastes, totaling 6 million tons annually, Coal mine wastes in the form of slurried solids from washing crude coal are second in volume, totaling 100,000 tons per year. They contain an average of about 40 percent coal. Salt is the third largest waste, amounting to 28,000 tons per year, Next is calcium carbonate, most of which is formed in water treatments, Because of its high unit value, chromic acid is important, although the waste quantity is much smaller; cyanide wastes are also significant because large quantities of sodium hydroxide and chlorine are consumed in their treatments prior to disposal. The various industries discharging wastes use 38 billion gallons of water annually; the recirculation rate is 109 billion gallons per year. The plants discharging no waterborne mineral wastes use 2 billion gallons of water per year and recirculate more than 1 billion gallons. Sand and gravel plants use 13.5 billion gallons; petroleum refineries use 10 billion gallons in direct use and recirculate 82 billion gallons per year.

Jan 1, 1962

By S. P. Pearton

"Pumpable emulsion explosives have been available to surface and underground massive mining operations for decades, and their unique properties offer significant advantages in terms of improved safety, reliability, and performance. However, the benefits of pumpable emulsions have been unavailable to narrow-reef mining operations due to the lack of technology necessary for their successful implementation in this challenging environment. Despite efforts to promote and enhance the safety and performance of bulk emulsions for narrow-reef stoping, little research has been undertaken to advance the pump technologies required for their implementation. This has resulted in a gap in knowledge and technology, and as a consequence the successful implementation of a pumpable emulsion system has consistently eluded the narrow-reef environment.The purpose of the following investigation was to evaluate the viability of pumpable emulsion explosives for use in South African narrow-reef mining operations. By approaching the problem from multiple perspectives, this research aimed firstly to propose a theoretical framework and suite of equipment suitable for the implementation of pumpable emulsions within the narrow-reef environment. Through the development of this suite of pumpable emulsion technology, tests could be undertaken on the proposed narrow-reef emulsion formulation and pumpable emulsion technology to obtain the necessary understanding of the performance of the system under controlled operating conditions prior to its implementation in the broader mining industry."

Jan 1, 2015