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By H. J. Bickel

This paper is concerned with general concepts and statistical devices used in projecting overall energy requirements. Particular emphasis is given to the use of individual end- use markets as an approach to developing future overall energy requirements, and translating these requirements into fuel consumption.

Jan 1, 1962

By M. C. Roberts

The material composition of product is defined as the quantity of metal used per unit of product manufactured during a year. The material composition of product has shown steady and persistent declines over time for most metals and materials. This tendency demonstrates the continued improvements in manufacturing technology resulting from substitutions of other materials and increases in production efficiency. The purpose of this paper is to use the material composition of product to show the impact of advanced materials on the use of traditional metals.

Jan 1, 1992

By J-Y Chen

China was once deficient in nickel and almost totally reliant on imports for its domestic needs, supplies mainly coming from Canada since the ending of imports from the U.S.S.R. in early 1960's. However, the discovery of the huge nickel/copper sulphide deposit in Jin Chuan, Gansu Province of northwestern China in late 1950's and its development and construction through the 1960's and 19701s, have much improved China's domestic nickel position. In 1985. China's nickel production has exceeded 27.000 tons, compared with only 7,000 tons in 1977. Today, Jin Chuan Nonferrous Metals Company operates two underground mines and a small open- pit; owns China's largest reserves of nickel and platinum, and the second largest reserves of copper and cobalt; and has become the most important subsidiary of China National Nonferrous Metals Industry Corporation (CNNC) which was established in April 1983. The Jin Chuan nickel-copper mines are located in Jin Chang City, Gansu Province, 1,700 km west of Beijing in the People's Republic of China (Figure 1). It is believed that Jin Chuan mines have the second largest nickel reserves in the world, after Sudbury basin, Canada. The deposits are situated on the north slope of the Longshu Mountains, 50 km north of Jin Chang City, and border on the southmost edge of the Gobi Desert plateau. The deposits were discovered in 1958. The total strike length of mineralized zones was approximately 6.5 km long, which was divided into four mining areas by faults (Figure 2). The Longshu underground mine of No. 1 mining area began development in 1959, with full ore production capacity of 1,000 TPD. The open-pit, also in No. 1 mining area, which was brought into operation in 1966 with ore output of 5,500 TPD, was closed down in 1982. The East Extension of the open-pit was put into operation in 1983; present production capacity is about 2,200 TPD. Nickel production of Jin Chuan mines in recent years, and production capacity of each mining operation, are shown in Tables 1 and 2.

Jan 1, 1987

Mill #4 processes mildly refractory ore from Carlin Trend deposits. Diagnostic analysis of plant operating data was used to generate a mathematical model containing the important parameters influencing gold recovery. The model was used to direct modifications to plant operating practice. The cyanide-dosing strategy was changed to reduce gold losses from preg-robbing and to cut reagent consumption. A finer grind was achieved without capital investment. The density in the carbon-in-leach circuit was lowered, and tighter control was exercised over the plant throughput. These changes resulted in a recovery increase of at least 2%, worth $111,000/month at $300/oz ($9.64/g) gold, and concomitant reagent cost savings of $55,000/ month.

Jan 1, 2000

By W. Perkins

The Smoky Canyon Mine has recently installed a PROMPTED GAMMA NEUTRON ACTIVATION ANALYSIS (PGNAA) on-line analyzer as part of a long-term advanced process control program. The on-line analyzer was adapted from a continuous dry analyzer and a large on-stream wet analyzer to a compact, multiplexed 3" slurry analyzer. The analyzation feed system utilizes a multiplexer system to accommodate up to fourteen (14) different plant process streams. The corresponding sampling system also provides for dewatering of sample streams too dilute for timely analysis. Key analysis includes, but is not limited to, phosphorus, aluminum, magnesium, calcium, and potassium. This data currently allows plant operations to be manually evaluated and controlled. Future development of a plant-wide supervisory control system will utilize the data for plant operations. This paper discusses the design, installation, and operation of the PGNAA on-line analyzer at the Smoky Canyon Mine.

Jan 1, 1996

By George A. Komadina

The Pima Mining Company lies 20 miles southwest of Tucson, Arizona, and some 45 miles north of the Mexican border. The mill is situated on a hillside overlooking Tucson and the Santa Cruz Valley, the ground generally sloping northeast at a 2.5 percent grade. The hillside location allows for gravity flow generally through the plant as well as for: tailing disposal.

Jan 1, 1965

By B. Holen, J. R. Baregi, J. A. Organiscak, A. B. Cecala

The National Institute for Occupational Safety and Health (NIOSH) cooperated with 3M Company in the design and testing of a new environmentally controlled primary crusher operator booth at the company’s Wausau granite quarry near Wausau, WI. This quarry had an older crusher booth without a central heating, ventilation and air conditioning (HVAC) system, and without an air filtration and pressurization system. A new replacement operator booth was designed and installed by 3M based on design considerations from past NIOSH research on enclosed cab filtration systems. NIOSH conducted pre-testing of the old booth and post-testing of the new booth to assess the new filtration and pressurization system’s effectiveness in controlling airborne dusts and particulates. The booth’s dust and particulate control effectiveness is described by its protection factor, expressed as a ratio of the outside to inside concentrations measured during testing. Results indicate that the old booth provided negligible airborne respirable dust protection and low particulate protection from the outside environment. The newly installed booth provided average respirable dust protection factors from 2 to 25 over five shifts of dust sampling with occasional worker ingress and egress from the booth, allowing some unfiltered contaminants to enter the enclosure. Shorter-term particle count testing outside and inside the booth under near-steady-state conditions, with no workers entering or exiting the booth, resulted in protection factors from 35 to 127 on 0.3- to 1.0-µm respirable size particulates under various HVAC airflow operating conditions.

Jan 1, 2015

By Michael Francis, Chris Darton

More than 55 km of tunnels have been constructed by TBM in the last 12 years to refurbish and upgrade the high voltage cable network in London. These include a tunnel of 20km length using EPBM machines in both clay and granular soils. Route selection was made with reference to subsurface structures, existing ground conditions, using suitable shaft locations addressing environmental concerns. The complex interfaces to manage included obtaining of consents to the coordination of multiple suppliers. The paper describes how all these challenges have been met successfully and how technology has been employed to provide for safe construction and operation in the congested urban environment.

Jan 1, 2003

By Yuanbo Zhang, Yikang Tu, Zijian Su

Stainless steel swarf is a typical by-product produced from stainless steel processing, which contains a significant level of valuable metals, such as iron, chrome, and nickel. About 1 million tons of stainless steel swarf are generated in China annually, but as mixed with impurities such as Al and Si, stainless steel swarf is not suitable to be directly smelted into stainless steel through refining process. In this study, stainless steel swarf was applied as a strengthening agent during limonitic laterite sintering process. The effects of adding stainless steel swarf on green bed permeability, the yield and quality indexes of the sinters, and the microstructure of the sinters were evaluated systematically. The results showed that the concentrated distribution degree of granules and green bed permeability were improved after adding stainless steel swarf. As the additional amount of stainless steel swarf increased from 0 to 3%, the tumble index and yield of the sinters rose from 50.07 to 54.69% and from 62.04 to 67.35%, respectively. The addition of stainless steel swarf would not change the phase compositions, and had little adverse impact on the metallurgical properties of the limonitic laterite sinters.

Aug 23, 2023

By Thomas V. Durkin

About 1.41 kt (45.2 million oz) of gold have been ! produced in South Dakota since 1875. South Dakota's mining laws attempt to strike a balance between economic development and environmental protection. Mining is promoted as an industry while prevention of pollution is required along with reclamation of affected lands to a beneficial use. The South Dakota Department of Environment and Natural Resources' (DENR) system of "one-stop shop- ping" for environmental permits streamlines the permit process. It fosters quick resolutions to compliance problems and helps keep enforcement actions out of the courts. Paha Sapa means "Hills that are Black" in Dakota Sioux. Appearing dark from a distance due to a thick forest of Ponderosa pine, the Black Hills were gold to many people. The exact date that gold was discovered in the Black Hills remains debatable. An inscribed stone tablet found in 1887 near Spearfish recorded these words:

Jan 1, 1998

By J. A. Herbst, R. Zaragoza

Conventional control schemes in use today are not able to produce satisfactory control when high-frequency disturbances are present in the flotation feed. An advanced model-based control scheme is presented here as a promising solution to this control problem. The main feature of this control scheme is the real time identification of the unknown disturbances in the first few cells of the flotation circuit. This information is used to control the rest of the flotation plant in a feedforward fashion. This control scheme also provides flexibility to meet any metallurgical, economical, or management objective.

Jan 1, 1987

By Zygmunt Sadowski

Problems encountered in barite flotation from various waste materials such as spent drilling muds are likely to be closely connected with the effect of chemical additives and metal ions present either added or present as contaminants, on the flotation. Fuerstenau and Palmer (1976) have studied in detail the adsorption of multivalent cations onto oxide and silicate minerals. It was observed that the adsorption of a multivalent metal species exhibits a sharp pH dependence which is related to the formation of hydroxy complexes of the metal ions in solution. Investigations on the recovery of barite from tailings ponds and mining wastes (Sullivan and Lamot, 1981) have shown that such barite materials can contain large quantities of carbonate and silicate minerals (including clay minerals). Also iron oxide slimes can be present. From these substances cations such as Ca2+, Mg2+, Fe2+ and A13+ can potentially dissolve and be present in the aqueous phase accompanying the various minerals. These ions and their hydrolysis products can have a substantial effect on any subsequent flotation scheme. The present study investigates the effect of the noted ions on both the stability and electrokinetic behavior of barite suspensions.

Jan 1, 1986

By Syd S. Peng

According to accident statistics (l, 2), roof fall accidents occur quite frequently at the intersections of underground? openings and account for up to 30% of the roof fall fatalities. But this figure will certainly go up considerably if roof falls not associated with any fatal accident are included in the analysis. Unfortunately, nonfatal roof falls are seldom documented. In the underground coal mines, there are two types of entry intersections. One is the three-way (V type) and the other is the four-way (T type) intersections. A three-way intersection occurs whenever the mainline track haulageway turns at an angle into a section haulageway. The four-way intersections by far the most common type in the U.S. under-ground coal mines are formed by the intersections of two entries which are oriented perpendicular to each other or by the intersections of entries and crosscuts. However, crosscuts are frequently driven at an angle to the entry to facilitate machine movements. The four-way intersections formed by this method of crosscut development are angled. At the intersection of two underground openings, the diagonal roof span is wider than the width of each individual opening. This is one of the major reasons why roof falls occur more likely at the intersections than in the entry between pillars. Consequently, special intersection support plans are usually employed (Figs. 1 and 2) for intersections. The most popular practices are to decrease roof bolt spacing 1 ft. less than or to increase roof bolt length 1 to 2 ft. longer than those employed in the entry between pillars (3). The increase in bolt length or decrease in bolt spacing can be applied to all of the bolts in the intersection or employed only for the strategically located bolts depending on the individual mine practices. These rather generalized practices seems to be adequate for some areas but in many cases inadequate for others. Occasionally, the neighboring two lines of chain pillars are staggered such that the crosscuts in one row of chain pillars face the centers of the chain pillars in the neigh-boring rows. This layout forms T-type three-way intersections which are also inadequate for most weak roofs (3, 4). A study was therefore initiated to develop special techniques for intersection supports. The first phase of the study was the analysis of the stress fields for the underground entry intersections. A three-dimensional stress analysis was necessary for this purpose. Unfortunately, the three-dimensional problems of complicated boundary conditions are beyond the existing analytical methods. The three-dimensional finite element method (FEM) was therefore employed in this study. In the analysis, square pillars of 40 feet wide and an entry height of 8 feet were assumed while entry widths varied at 14, 20 and 26 feet. This model was selected to simulate the mine where roof falls data were collected. The second phase of the study was the collection of field data. The sizes of the roof falls including heights, lengths and widths were collected and analyzed. In the third phase study, the results of the first and second phases were compared and discussed. The analysis of field data revealed an arching zone within which roof falls occurred. The arching zone above an entry obtained empirically was compared with the calculated stress contours. Assuming that the bolts must be anchored in the rock strata outside the arching zone, the preferable systems of bolting were proposed. Also the amount of pretension required to inhibit sliding between layers was discussed.

Jan 1, 1978

By John W. Welty

Volcanic activity occurred during six periods of Arizona's geologic history. Precambrian volcanism occurred in two pulses at 1.8-1.6 billion years (b.y.) ago and at 1.2-1.1 b.y. ago. Volcanism occurred again in mid-Jurassic and Laramide (Late Cretaceousearly Tertiary) time. Volcanic rocks from these times are not used commercially in any significant quantity. Middle and late Cenozoic magmatic activity covered large areas of Arizona with voluminous volcanic rocks. During the mid-Tertiary magmatic pulse, explosive silicic magmatism, with eruption of areally extensive ash-flow tufts, covered large areas in the Basin and Range Province, while the Colorado Plateau remained largely unaffected. Basalt eruption also occurred during and immediately after silicic volcanism, leading to compositionally diverse suites of volcanic rocks. Late Cenozoic volcanism occurred throughout Arizona and was dominated by wide-spread eruption of basalt flows with local cinder-cone clusters and siliceous volcanic deposits. Perlite deposits near Picketpost Mountain in northeastern Pinal County account for the bulk of the industrial uses of mid-Cenozoic volcanic rocks. Other perlites of presumed middle Tertiary age are present in central, southeastern, and western Arizona, but to date remain unexploited. Arizona Fire Agate is a valuable gem material and is associated with volcanic rocks of middle Tertiary age. Basaltic rock of this age also is utilized in the manufacture of rock wool for insulation. Late Cenozoic volcanism produced most of the industrial-quality volcanic rocks. Basalt, cinder cones, and materials of rhyolitic composition are commercially exploited by municipal and Federal agencies and private industry for aggregates, road conditioners and maintenance materials, asphaltic concretes, cinder block construction, pozzolans, and landscaping. These deposits are generally confined to the Flagstaff and Springerville areas. A famous peridot gem locality is associated with late Tertiary basalts at Peridot Mesa on the San Carlos Indian Reservation. Important products derived from altered volcanic materials of late Cenozoic age include clay and zeolite. Arizona's volcanic-rock sequences are still incompletely known, particularly in central and western Arizona. The potential for recognition and exploitation of important new deposits of useful volcanic materials is high.

Jan 1, 1987

By Alexander N. Winchell

"THE MICHIGAN COPPER DISTRICT.Location. The copper mines of Michigan are all in the north¬ern part of that state on the Keweenaw Peninsula, which extends from the (Michigan) mainland for about seventy miles northeast¬erly toward the middle of Lake Superior. The mines occur in a belt or zone occupying the central portion of the peninsula from end to end.. The most productive mines for many years past have been those located not far from the city of Houghton in' the central part of the zone, in a section extending about ten miles southwest of Houghton and fifteen miles northeast. The most important mines in order of.location, from the northeast to south¬west, are the following: Mohawk, Ahmeek, Allouez, North Kearsarge, Wolverine, South Kearsarge, Centennial, Calumet. and Hecla, Osceola, Franklin, Quincy, Hancock, Isle Royale, Superior, Baltic, Trimountain, and Champion. The first three named are in Keweenaw county and all of the others are in Houghton county. Still farther to the southwest are the Lake, Mass, Adventure, Michigan, Victoria, and White Pine mines. These are in Ontonagon county.History. The exploitation of these copper mines extends back into prehistoric times. There is little evidence that the American Indians carried on mining operations in this region in the period shortly before the advent of white men, but there is abundant evidence that the ancestors of the Indians, •or some earlier inhabitants of the region, carried on primitive mining operations. For example, Mr. S. O. Knapp, Agent of the Minne¬sota Mining Company, in the winter of 1847-48, made the first discovery of prehistoric mining. This event is described as fol ,lows by Foster and Whitney : Location: As shown on the accompanying map, the Mar-quette district extends from the region of Marquette on Lake Superior westward for about forty miles. The main basin of the district is only about three to six miles wide, but outlying areas which are commonly regarded as belonging to the same mining unit, make the north and south dimension of the district about twenty miles. The most productive portion of the area is in the vicinity of Negaunee and Ishpeming, .about ten miles from Mar¬quette, but important mines are found also all along the range as far west as Michigamme and also to the south in the fold known as the Republic Trough. Comparatively recent developments indicate that important ore bodies have been developed in the outlying Swanzy district about eighteen Miles nearly due south of Marquette.The Marquette Iron District.History: The first discovery of iron ore in the Lake Supe¬rior region was probably that made in 1844 near the site of Ne-gaunee by the government surveying party in charge of William A. Burt, sent out under the direction of Douglass Houghton. This surveying party was using a solar compass, invented by Mr. Burt, and noticed variations in the direction of the magnetic needle at various times and places, but. on the 19th of September, while running the east line of Township 47 North, Range 27 West, the needle varied from its normal position until it stood nearly at right angles thereto."

Jan 1, 1920

By Steven J. Schatzel, Kayode M. Ajayi, Marcia M. Harris, Zoheir Khademian

Predicting rockmass permeability is critical in evaluating various engineering designs, including estimating gas inflow to a longwall mine in the case of a hypothetical breach in the gas well. This study conducted field permeability measurements to validate a geomechanical model capable of predicting rockmass permeability during longwall mining. A series of slug permeability tests were conducted in an active mine in Pennsylvania. A model of the mine was constructed in 3DEC numerical modeling software, and permeabilities were calculated. The modeling results agreed well with the pre- and post-mining permeability measurements, showing the applicability of this tool to evaluate gas well stability near mine workings.

Feb 1, 2024

By W. W. Atkinson

This paper describes some concepts developed in a geologic data recording system at the Victoria, Nevada breccia pipe-skarn copper mine. The recording system is not fundamentally new, but represents expansion of earlier ideas. The paper is based on the philosophy that a high quality geologic data base is necessary and that it should be complete, clear, standardized, neat, quantitative, and readily useable. It may be multi-colored or simply black and white. Graphic, descriptive and quantitative recording of data is essential. A format for core logging is presented and discussed and as well as a multiple overlay system for recording data gathered in surface mapping.

Jan 1, 1983

By J. W. Francis

The paper about to be presented deals with the relatively straightforward problem of mining two seams of coal separated by an interval. This may seem to be a simple problem but within a twenty-mile radius of Consolidation Coal Company's Burning Star # 4 Mine at least seven (7) different techniques of two-seam mining have either been tried or are now in use. This great variety of techniques should point out that there is no single simple solution; a conclusion often reached when dealing with mining problems. As a background for the techniques presently in use at the Burning Star # 4 Mine, we will briefly outline the other five (5) stripping techniques used in the area: 1. Captain Hine 6360 Range Diagram (Figure 1) 2. Leahy Mine Range Diagram (Figure 2) 3. Burning Star # 3 Mine 5860 Range Diagram (Figure 3) 4. Burning Star # 3 and # 4 Mines Dragline in Pit Range Diagram (Figure 4) 5. Captain Hine 2570/5561 Range Diagram (Figure 5) Each of these techniques was chosen because it provided the best and least expensive alternative for mining the coal under the particular restraints encountered. The Mine Engineers at our Burning Star # 4 Mine, Mr. Dennis Mahan and Mr. William Weaver, will now detail two additional mining techniques, out-lining our experience to date.

Jan 1, 1977

By P. Hambach

Murer Company, Andermatt, Switzerland, can claim to have done pioneer work in the construction of inclined shafts. This happened in 1968/69, when we decided to bore with a Wirth tunnel borer an inclined shaft, 1100 m in length, 3.0 m in diameter, and with a grade of 65%, in the 2400 kilo pascall per sq. cm granite of the Montblanc Massive. The whole excavation was accomplished in ten months which, at least for European conditions, can be claimed as a record. It was, at least to our knowledge, the first inclined shaft to be bored full-face (Fig. 1). Encouraged by the experiences and performances attained at Châtelard, we approached other projects of the same kind. We were awarded, together with Hochtief Ltd., Essen, a contract from Schluchseewerke, Freiburg, Germany, in December 1969, for the construction of a penstock for the Hornbergstufe at Wehr, Germany, with a diameter of 6.3 m. This inclined shaft with a grade of 55% is located in Schwarzwalder granite with a compressive strength of up to 2000 kilo pascall per sq. cm, about 31,000 psi. As no exact geological data were available about the rock to be worked, and a fault zone from 80 to 150 m long had to be faced, as well as a few individual fissures of varying thickness, it was decided to use the multi-stage method. The 3-m diam tunnelling machine which had driven the oblique shaft at Châtelard had now finished work, and an immediate beginning was made with driving the pilot staft. This was very welcome to the contractor, since exact information about the type of rock present and the inflows of water was required immediately and before the final borehole diameter was fixed, for the purpose of dimensioning the supports to be subsequently installed.

Jan 1, 1974

By Pedro E. Rengifo

Splicing methods have undergone considerable developments over the last 2Oyears. Continuous conveyor belt service is dependent entirely on the strength and life of the splice to hold the two ends together. Ultimately, belting performance is dependent on the quality, efficiency, and technique of the splicer. As customers demand better belting performance and running tensions increase, the need for splices that perform as efficiently as the belting has increased also. Higher dynamic belt constructions have also dictated the need for "new"sp1icing techniques. Regardless of the belt type used or spliced, one item that is most necessary with all belt types is the quality of the workmanship and standardized splicing methods that employ all of the necessary elements required to ensure reliable field service. This paper will explore the use of Goodyear-issued internal standards for field splicing following the constraints of quality and efficiency for fabric and steel cord reinforced belting. Also included are the 10 most common mistakes made by splicers, Goodyear-issued Field Quality Assurance Standards, and check lists for end users to adhere to the manufacturers' requirements for splicing including materials and specifications for conveyor belt splicing and repairs.

Jan 1, 2004