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By P. R. Bridenbaugh

The products of the coming decade will possess such stringent design criteria that it is unlikely today's monolithic materials will be able to meet them. The discovery, characterization and cost- effective manufacture of a whole new generation of highly engineered materials therefore have become essential requirements for participation in the materials marketplace of the 1990s and beyond. Meeting these challenges will require advances on a broad variety of scientific and engineering fronts, including: strengthened fundamental understanding of materials behavior; composite and laminate programs offering the compatible and synergistic combination of metals, ceramics and polymers; advanced engineering and structural design techniques; processing technologies capable of producing advanced materials efficiently; and, the development of new products taking advantage of the availability and cost-effectiveness of these highly engineered, advanced materials.

Jan 1, 1986

By Y. Pan, P. Tukkaraja, R. BHARGAVA, V.V.S. VYTLA, S.J. SRIDHARAN

Panel caving is an underground bulk mining method that uses gravitational force to mine massive, steeply dipping and deep-seated ore deposits at lower operating cost. To control dust and gas emissions entering the production level during the extraction of ore from the draw points in a panel cave, relatively negative pressure is created in the cave by installing an exhaust fan in the exhaust drift located on top of the cave. As caving is a dynamic process, designing an effective ventilation system is challenging; therefore, estimating the airflow resistance offered by the broken rock inside the cave is critical. This study investigates the effect of changes in the bulk porosity of the broken rock on the cave airflow resistance using the computational fluid dynamics (CFD) approach. The results show an inverse relationship between the cave airflow resistance and the bulk cave porosity. The pressure-quantity characteristic curves presented in this paper provide valuable information for sizing and operating an exhaust fan used for a mature panel cave ventilation.

Nov 1, 2022

By Joseph M. Denk, Gary J. Wirth

This paper summarizes a three phase face ventilation study which was conducted from September 1989 through March 1990 to determine face area methane liberation patterns on two extended longwall sections. The coal seam being mined was considered gassy and the mine liberated an average of 14.4 million cubic feet per day (cfd) or 0.41 million cubic meters per day (cmd) of methane through the mine fans. The mine also used an extensive underground degasification program to recover up to 13.4 million cfd (0.38 million cmd) of methane. Data was collected while the longwall sections were mining from the beginning, middle and end of panel extraction to determine the relationship between the methane liberation and extent of longwall retreat. As expected, methane concentrations did increase from the headgate (intake) to the tailgate (return) side of the longwall face and peak concentrations were detected above the shearer as it passed a methanometer location during mining. There were significant differences in the methane liberations due to the location of the active face within the longwall panel. Results from this study could be used to determine a minimum design face air quantity for an extended longwall section operating under similar conditions.

Jan 1, 1991

By G. D. Bates

INTRODUCTION The Magmont mine is a joint venture of Cominco American Inc. (operator) and Dresser Minerals, Inc. The mine-mill operation is located approximately 160 km (100 miles) southwest of St. Louis, MO, in what is commonly referred to as the "Viburnum Trend.” The Magmont mine is designed for a production rate of 3810.2 t/d (4200 stpd) on a 5-day week, three shifts per day basis. Initial production began in 1968. The mine is open stope, room-and-pillar, and essentially horizontal along the trend of the ore body. Briefly, the main geological structure can be described as a brecciated graben bounded by reverse faults. The ore body in cross section is shaped like a bell curve with some lateral extension at the lower part. Presently outlined ore is 609.6 to 762 m (2000 to 2500 ft) in width and 2133.6 m (7000 ft) in length. The ore varies in thickness from 4.87 m (16 ft) on the fringes to an average of 27 m (90 ft) in the high ore areas bounded by the reverse faults. Lead is the primary metal with zinc and copper secondary. MINE DESIGN The basic design of open stope, room-and-pillar mines has been described by several writers and need not be repeated here. (Anon., 1970; Bullock, 1973; Casteel, 1972; Christiansen et a]., 1970; and Lane, 1964) This discussion covers the mining sequence as applied to the particular problems at the Magmont mine, the use of equipment, and deployment of the work force. In the upper portion of the Magmont ore body is a layer locally called the False Davis shale. This layer lies below the true Davis shale, is normally interbedded with dolomite, is of varying thickness, and if mineralized, is included in the top pass of the mining sequence. In thick ore areas this layer will be 2.13 to 2.43 m (7 to 8 ft) in thickness and will occur in the upper portion of the pillars. Due to its incompetency the presence of this False Davis layer is of primary concern in mine planning and operation. Mining areas are divided into three basic groups by ore thickness. First are areas of ore up to 6.09 m (20 ft) in thickness. These areas are below the False Davis shale and are mined single pass with drill jumbo. Second are those areas up 13.71 to 15.24 m (45 to 50 ft) in height. The first 4.87-111 (16-ft) Pass is taken at the top of the ore and the back and pillars secured. Benching the lower portion(s) in 4.57 to 4.87-m (15 to 16-ft) passes is then done with either a drill jumbo drilling horizontally or a crawler drill drilling vertically. Normally these areas are below the Table 1. Productivities per Manshift False Davis shale. These areas may also be mined by back slashing, or overhand benching, where the first 4.87-m (16-ft) pass is taken at the base of the ore and successive 4.87- m (16-ft) passes are taken upward. A minimum amount of back slashing is done at Magmont since it requires repetition of roof control on each pass and roof control is the single largest stoping cost at Magmont. Ore left to provide a working platform oxidizes and is coated by oil spills thus reducing metallurgical recoveries. The third mining area is over 15.24 m (50 ft) in height UP to a maximum of 40.23 m (132 ft) and will encompass the False Davis shale. These areas are mined by first driving +15% inclines to the top of the ore body. The top pass is mined and the back is bolted and roof mats installed as a matter of standard practice to minimize roof problems as mining progresses downward. Once the back and pillars on the top pass are secured, benching begins on successive passes with either the drill jumbo or crawler drill. Pillars on all successive passes below the top pass are secured as necessary. While benching progresses below the top pass, the pass at the base of the ore body is mined leaving a sill of 4.57 to 7.62 m (15 to 25 ft) in thickness to be removed with the crawler drill in a retreating manner. Rooms are mined on a 1.57 rad (90") grid pattern to insure alignment of pillars where multiple passes are taken. Pillars are designed on a 17.98-m (59-ft) spacing with rooms up to 10.66 m (35 ft) in width. Heading widths are wide enough for the mobile equipment to turn without additional allowance for curves. The result is a flexible layout which provides a maximum number of headings available for high extraction rates and grade control. PRODUCTION Incentive Bonus Incentive bonuses play an important part in the mine production at Magmont. Production crews are trained to perform only one of the mining functions of drilling, blasting, mucking. or roof bolting. This specialization, or functionalization, is augmented by development to open all possible stoping areas as early as possible in the life of the mine. This insures that each crew will have enough headings to perform its specialty. The incentive bonuses increase exponentially as output increases. The lucrative incentive bonus coupled with the specialization of the production crews and proper mine development have combined to give the high productivities shown in Table 1. Development crews perform all mining functions in their area. The incentive bonus is paid on a per foot basis, Crews on different shifts working the same heading share equally in the bonus proportional to their contract hours worked.

Jan 1, 1982

By V. Karra, G. Beerkircher

Application of the innovative WaterFlush® crushing technology to the processing of gold, copper, and iron ores is presented for retrofit circuits and productivity gain in each case is stated. New operations containing WaterFlush are described in brief.

Jan 1, 1995

By Marie-Josée Banwell, Cyriac Sebastian, Giacomo Falorni, Sara Del Conte

Interferometric Synthetic Aperture Radar (InSAR) is a satellite-based monitoring technique that complements other in-situ methods for detecting and measuring surface displacement. Recent advances in data processing algorithms, coupled with the use of high-resolution satellite systems, make it possible to now provide high-frequency InSAR monitoring services, with updated results delivered every time a new satellite image is acquired. The advent of large, continuously updated data sets, however, brings new challenges, including the need to rapidly sift through the data to identify only those points showing relevant ground displacement information. This has been achieved by using trend variation analysis tools, that quickly isolate and highlight only areas of anomalous behavior. The paper focuses on project case studies where continuous InSAR monitoring has proven to be key in identifying displacement trend changes near tunnel alignments.

Jun 13, 2021

By Norman K. Olson

Hard-rock phosphate was formerly the chief source of all phosphate in Florida. Its mining began as early as 1883 or 1884, reached a peak level in 1907 and ceased in 1966. Production began and ended in the Dunnellon area (Marion County). Nearly all the hard-rock was exported because its P205 value per unit weight is generally more concentrated than that of other phosphate rock. Maximum production, achieved in 1907, was greater than 600,000 tons; the total value for that year was more than $4,000,000. The Florida hard-rock phosphate, considered to be of middle Miocene to early Pliocene age, has an intermittent narrow, linear northwest-southeast trend. The Ocala uplift controls the phosphate distribution for more than 200 miles. Other known, isolated hard-rock areas appear to be related to minor folds on the Ocala uplift. The hard-rock phosphate deposits are a heterogeneous mass of sedimentary fluorapatite, chert and quartz with textures ranging in size from clay to boulder, and in thickness from 0 to 40 feet. Phosphate compounds, principally fertilizers, have been in oversupply since before 1968, but by the middle 1970's some experts forecast a supply-demand balance. A brighter future for exploitation of Florida hard-rock phosphate depends upon one or more of these factors: 1) depletion of present premium grades (74 percent BPL and above) of land-pebble; 2) cheaper electric power from nuclear generators for profitable electric furnace operation; 3) supply and price of sulfur; 4) manageable rail-water transportation costs; 5) development of less costly mining and separation methods; and 6) minimum competition from high-grade foreign phosphate.

Jan 1, 1972

By Arnaud Colson

1 Good morning ladies and gentlemen. Let me first thank you for welcoming me to this international congress. I?ll have the pleasure to explain to you how the Lafarge group works on its quarry rehabilitation. I will deal with the way quarry rehabilitation has affected all branches of the group trough a global approach. 2 Quarries often are a subject of controversy dividing those are for and those who are against. My purpose is rather to examine where factors of progress lay and how in a quarry such as Lafarge we can include quarry rehabilitation, which is so fundamental dimension of our process. 3 - 4 As these two photos of French quarry show taking into account the environment in the quarry industry has been a recent preoccupation. In less than a century rehabilitation has a dramatically evolved in a positive way. Consequently our group integrate an ecological dimension in its activity. It?s an ethical question as well as a personal view of our role as a responsible industrial group. 5 My presentation is built around 4 points: I?ll begin by explaining why it?s our responsibility to rehabilitate quarries. I?ll go on to fill you in on the method of the project. After that I?ll outline the expected results. Finally I?ll talk about the rest of the project and the way we can ensure this know how.

Jan 1, 2002

By Frank J. Markewicz

The expanding: demand for ilmenite for use in the manufacture of titanium pigments, the knowledge that much of this raw material comes from distant points and therefore has to include a heavy freight charge in the price of the delivered product, and the further knowledge that ilmenite occurs both in the crystalline rocks of northern New Jersey and also in some of the Triassic igneous rocks, were considerations which led to a search for ilmenite-bearing sands in southern New Jersey. That this search was successful is now history, and it is the senior author's privilege to state here that most of the credit belongs to his associates who did all of the heavy work of hand-augering for samples, and who made all of the heavy-mineral separations. We all are grateful to members of the Department of Geology at Rutgers and Princeton Universities for the use of equipment which enabled us to evaluate certain samples from our ilmenite exploration program. In addition, we wish to express our appreciation to many companies for their cooperation and for their permission to publish mineral and chemical analyses. We also acknowledge with much appreciation our debt to the geologists and engineers with whom we have had many lively and rewarding discussions relative to the ilmenite deposits.

Jan 1, 1958

By Michael M. Kimberley

Stratiform uranium deposits occur in Canada along the north shore of Lake Huron near the base of the Middle Precambrian Huronian Supergroup. Outcrop of the Buronian Supergroup extends for over 400 km from Sault Ste. Marie in the west eastward through Sudbury and then northeastward to Cobalt. Maximum stratigraphic thickness exceeds 5 km. The predominant Huronian rock type is metamorphosed sandstone (quartzite), with sub- ordinate argillite, conglomerate, mixtite (possibly tillite), volcanic rocks, and minor limestone, Much of the quartzite is highly feldspathic. Substantial uranium ore was first discovered in Huronian rocks in 1953 and has been exploited continuously since the initial mine-mill plant was constructed at the Pronto ore body, 30 km south of the present townsite of Elliot Lake. Only one ore body remains in production, however. It is shared by Rio Algom and Denison Mines 14 km north of the town of Elliot Lake.

Jan 1, 1980

By Ginger L. Hustrulid

Conveyor belts are a critical component in tunneling projects. This paper reviews current design considerations for conveyor belts. Rubber compounding differences to meet local fire resistance regulations or certain cover characteristics such as higher abrasion resistance or low carbon footprint rubbers for applications are reviewed. Evaluation of fabric belts, steel cable belts and the benefits of each carcass design for a particular use is also examined to help with proper carcass selection to decrease downtime from unexpected failures. Finally, this paper takes a look at some of the differences when working in metric versus imperial units.

Dec 1, 2022

By MOHAMED WAEL, ANASTASIA GOEVA, ABDULAZIZ TAWFEEQI, IHTISHAM TARIQ, S. M. ZAKIR HOSSAIN, NIAZ ALI KHAN, MUHAMMAD FAISAL IRFAN

Carbon dioxide (CO2) mineral carbonation is a carbon capture and storage (CCS) technique that can sequester CO2 permanently in the form of durable carbonate minerals. Extendable permanent storage capacity — onshore and offshore storage reservoirs — and the exothermic nature of the mineralization process make this technique attractive [1]. In the present study, maximum carbonation efficiency for aqueous mineral carbonation was achieved through two steps: optimization of calcium leaching from cement kiln dust followed by the reaction of pure CO2 with the calcium hydroxide precipitates formed by hydroxylation using sodium hydroxide (NaOH). Optimization of calcium leaching is highly important, as it is a rate-limiting reaction step in mineral carbonation and also influences and enhances the carbonation efficiency. To maximize the calcium leaching as well as carbonation efficiency, response surface methodology — with either Box-Behnken design or central composite design — was applied. It is the most well-known statistical, fully randomized and bias-free method for determining optimized conditions using quadratic regression models.

By Timothy C. Smith, S. Andrew Jacobs, Douglas E. Gonzales, Sandy J. Schexnailder, Carl Urban

At the Schwartzwalder Mine (Cotter Corporation, Golden, Colorado) ion exchange resins have been used in mine water treatment experiments. The experiments, initiated in October 1979 and currently in progress, demonstrate that mine water uranium values can be reduced to levels as low as 10 ppb. Duolite® A-101D, a strongly basic anion exchange resin, was tested in laboratory-scale columns (1 inch diameter) initially and then in pilot-scale columns (4 inch diameter), using both co-current and counter-current operational modes. Observations and conclusions resulting from these studies can be summarized as follows: (1) Duolite® A-101D appears to have successfully extracted uranium at influent levels of approximately 2.0 ppm over multiple loading and elution cycles, consistently producing effluent concentrations as low as 10 ppb uranium. (2) Based upon present test data, counter-current regeneration appears to be the key to successful operation. Upflow loading and downflow elution are the preferred modes for service and regeneration, respectively. (3) Filtration is a necessary pretreatment to remove fine clay and inorganic precipitates that will foul the resin, causing excessive pressure drop and poor loading and elution kinetics. (4) This waste treatment application is unique in that it offers the opportunity to recover some or all of the capital investment in the treatment facility

Jan 1, 1980

By T. P. Meloy

Improvement of grade and recovery requires the use of optimum processing circuits. Critical to an optimum circuit is the set point for separation. With the introduction of the concept of circuit analysis (Meloy, 1982), it became possible to determine optimum circuits for a given task. No analysis, however, has yet been made as to the grade requirements of the larger circuits. Williams and Meloy (1982), reviewed the literature and concluded that, within the operating range, most unit operations involved in particle separation behave linearly. For the purposes of this analysis, linearity will be assumed. Grade, G, is defined as the weight of the coal mineral, C, that appears in the product, divided by the weight of the coal mineral plus the weight of the gangue mineral or waste mineral, Q, which appear in the product.

Jan 1, 1982

By S. D. Bearden

The world's reserve base is adequate for at least 100 years at the current consumption rate. China, India, and the U.S. are expected to remain the leading producing countries. The U.S. will continue to be the largest consumer of the production. None of the known substitutes for barium sulfate are expected to impact existing applications. World production in 1995 was 4,410Mt. This is about 50% of the projected capacity. Consumption is directly proportional to hydro-carbon well installation activity. Imports are expected to continue to supply more than half of the U.S. requirements.

Jan 1, 1997

By E. Berrezueta

Automatic digital phase imaging should yield unbiased and representative characterizations of gold ores. However, this is not a simple tusk due to low gold grade, fine grain size, possible complex mineralogy, nugget effect, etc. Using the same sections of a gold-rich ore, a critical test was performed using an optical microscope (OM) and an electron microscope (EM). In general, the two methods are consistent and useful for ore processing. There are some minor differences, such as the detection of very fine gold grains is enhanced by EM. Key words: Digital imaging, Gold ores, Mineralogy, Electron microscopy, Optical microscopy

Jan 1, 2003

By Ricky Chipka, Roshan Thapa, Richard Yovichin, Greg Rogoff, Patrick Niemuth

A 4.5-mile-long, 96-inch-diameter outfall pipeline was constructed between North Texas Municipal Water District’s proposed Sister Grove Regional Water Resource Recovery Facility and the Stiff Creek Discharge Structure. Two TBM-mined tunnel segments were excavated for the outfall pipeline through rock and mixed-face conditions within the Austin Chalk Formation. The TBM mining performance was tracked in detail and evaluated during mining. This paper discusses the TBM configuration, TBM utilization, advance rates, and challenges of both tunnel segments.

Jun 13, 2023

An open pit production planning method for stage mining is presented in this paper. The method brings solutions to the four most important parameters in stage mining : 1) the number of stages, 2) the size and geometry of each stage pit, 3) the mining sequence of the benches in the stage pits, and 4) the time of transition from one stage to the next. The method can also simultaneously optimize the ultimate pit, mine life, and production rate in each stage.

Jan 1, 1996

By Ronald Allum

Underground copper mining at Magma Copper Company's San Manuel Mine has been un going since 1955. The block caving mine has been producing copper ore at the rate of over 16 million tons per year. Depressed market conditions during the 1980's forced Magma to look at new technology. Late in 1984, Magma began testing new equipment and mining methods at the underground mine at San Manuel, Arizona. The tests resulted in a move towards mechanized production using new procedures and equipment. The goal was to increase efficiency and cut costs through mechanization.

Jan 1, 1988

By J. B. Ackerman, C. S. Bucans

The Sunshine Mining Co. has recently started up its new silver refinery in Kellogg, ID. The new plant recovers silver anc copper values from a high grade tetrahedrite concentrate using hydro- metallurgical processes. The plant and process are both new and have gone through the initial startup phase during the first six months of 1985. The full scale plant was developed from laboratory test work. While the metallurgy of the process worked as expected, the material handling problems were difficult to over-come. As might be expected, those parts of the plant that represented available technology started up easily, while the parts that represented new technology presented the most difficulty. Topics covered in this paper include: 1) insufficient type and amount of agitation in the leach vessels, 2) discharge of a non- homogeneous slurry from the leach vessels, and 3) problems associated with very low flow rates in slurry lines.

Jan 1, 1987