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By William G. Doepken

The extensive use of rubber-tired support vehicles as a complement to a fleet of load-haul-dump and drill jumbo units has proved invaluable in maintaining scheduled multilevel/multiheading development drifting advances at the Henderson Mine. Support equipment, whether self-powered or towed, releases primary drill-blast-muck equipment from the supportive functions of ground control, utilities installation, steel and concrete construction and supply handling, thus providing both balance and increased flexibility to an underground, rubber-tired mining system. Experience has indicated that increases in man productivity and improved safety and working conditions coupled with decreases in overall costs and mining cycle times are realized with the inclusion of support vehicles in the mining fleet.

Jan 1, 1976

By S. K. Mukherjee, M. M. Singh, N. I. Jayaramn

In underground mining operations, ventilation and water sprays are the common methods of controlling dust. In recent years, there has been a proliferation of technical literature dealing with water sprays for dust control. However, guidelines for the design of an effective water spray system have not been presented to the mining industry. This paper recommends guidelines for water spray systems to control dust in underground mining operations. These guidelines suggest type, number, location, and orientation of nozzles; desirable operating water pressure; and associated filtration system.

Jan 1, 1987

By C. O. Brawner

Geotechnical theory is reasonably well developed to evaluate the stability of rock slopes for surface mining projects. It is recognized widely that structural geology, groundwater pressures and seepage, and blasting are key factors that influence the stability of such slopes. However, our capabilities to model the structural geology, to determine rock strength along discontinuities and to model groundwater pressures and profiles are still very approximate. Plus, practical experience of the rock mechanics engineer is one of the most important inputs to the design of open pit mine slopes. To emphasize the use of practical experience, a number of case examples are reviewed here to illustrate key factors that must be evaluated. These case examples comprise a continuation of other examples presented in the Jackling lecture to the SME in 1986 by the author (Brawner, 1986). Example no. 1 In situations where the orientation of geologic discontinuities will not influence rock slope stability, extremely steep slopes can be developed, providing blasting and groundwater are controlled adequately. An excellent example of this condition is the Republic Pit of Cleveland Cliffs in Michigan. The rock slope in Fig. 1 isover400fthigh with a face angle of approximately 80". The rock is hard and massive, and blasting was carefully controlled. The original design of this slope was at45", a standard design angle at that time. The competency of the rock and the lack of critical geologic structure subsequently was recognized, and the much steeper slope angle was developed successfully. The rock proved to be so competent and the slope sufficiently stable that an underground crusher station was developed with entrance and exit tunnels excavated at the toe of the steep wall.

Jan 1, 1991

By R. C. Warner, L. Mills, S. D. Botts, M. Marticorena

The Antamina Mine is located in the mountainous region of the Ancash Department of Peru at an elevation of approximately 4200m.The 120 km main access road crosses the headwaters of numerous high-value trout streams and is adjacent to pristine lakes, some of very high ecological and scenic value. In addition, the mine discharges mine water and tailings supernatant to the Antamina and Ayash watersheds. These streams provide the primary water supply for irrigation by local residents and provide excellent fishery habitat. The rock walls and earthen diversions constructed by historic and current indigenous residents of Peru are world-renowned and local residents continue this tradition, passed down from the Inca Civilization, for both agricultural purposes and water distribution. The key elements of sustainable development – economic, environmental and social development have been incorporated into Antamina’s sustainable development program through integration of indigenous knowledge and capabilities into enhanced storm water, erosion reduction and sediment control systems. Examples of incorporating indigenous technologies and knowledge into cost-effective and environmentally sound environmental controls are:(1) placement of rock walls on steep terrain to reduce slope length and erosion, (2) installation of rock walls (porous rock check dams) within elongated sediment ponds to increase detention time, (3) construction of rock-lined ditches to convey clean water (4)use of rock walls, with or without geotextile, to function as a seep berm, and (5) appropriate selection and usage of native Andean species for protection of canals and sediment ponds, and steep slopes.

Jan 1, 2004

By Norman F. Schulz

The technical excellence of separation achieved in a mineral concentration process, or any other process where two constituents of any kind are physically separated from each other, is expressed uniquely and quantitatively by the Separation Efficiency: ES = (R ? Rg) where R is the percentage of the valuable constituent and Rg the percentage of the waste appearing in the concentrate. The Separation Efficiency meets all the usual requirements of a true efficiency and is independent of the nature of the process used. It can be visualized as the percentage of the feed material that, in effect, actually undergoes complete separation while the rest of the feed is distributed randomly and unchanged into the two separation products.

Jan 1, 1969

By L. B. Hales

Color video or digital cameras have been installed over flotation cells to monitor color, bubble size, froth movement, and other characteristics. These systems are designed so that the camera provides flotation performance information just as any other sensor might. Factorial tests have been run to monitor and measure the variation in froth characteristics as a function of flotation control settings. Ultimately, it is envisioned that froth image sensors can be used to monitor and control the flotation performance as effectively and for less cost than current analytical systems.

Jan 1, 1999

By H. Do, R. Yoon

Mineral flotation is effective over a relatively narrow particle size range of approximately 10 to 100 µm. If the upper particle size limit can be increased, however, a run-of-mine ore may be coarse ground, and only the middlings are ground further to achieve required grades. This will result in significant energy savings and increased throughput. In this communication, methods of increasing the upper particle size limit will be discussed on the basis of a flotation model that can predict flotation from both hydrodynamic and surface chemical parameters. An example of increasing flotation recovery by control of a chemistry parameter is given.

Jan 1, 2007

By Thomas J. Neil, O&apos

Most analysts find that progress has been evolutionary in any technologic field. To be sure, a few discrete breakthroughs can usually be identified, but viewed in its entirety, the curve of technologic progress over time tends to be relatively smooth with few discontinuities. Even in those cases where a major scientific discovery is achieved, the rate of technologic progress is limited by the often surprisingly slow rate of commercializing the concept into usable products. Whereas discovery and invention tend to be discrete events, technical innovation is often a painfully slow process. In spite of overall gradual change, technologic progress in most fields, when viewed in retrospect, tends to reveal certain relatively homogeneous periods where little change is evident, separated by episodes of accelerated progress. Thus, open-pit mining over the past century has changed from predominately train haulage to truck haulage and is now experiencing a major increase in belt haulage. Ore reserve estimation is another field that fits the same pattern, and the history of mine evaluation lends itself to a similar analysis. Evaluating mine investment opportunities is a fascinating aspect of mining. The unique set of risks inherent to every mining project is particularly intriguing. Geologic risks are most obvious, since faulty ore grade and tonnage estimates are among the leading causes of mine failures. Wide swine's in mineral commodity prices are usually cited as another major risk in mining. Because any ore deposit is a finite resource and the miner has limited discretion in selecting a mining sequence, mines are generally at the mercy of notoriously fickle commodity markets. There is a tendency for many mine investment analysts to feel that mineral market uncertainties are unprecedented in severity. Of course, prices in other markets rise and fall also-in some cases as precipitously as with minerals. However, two other mining characteristics tend to compound this marketing risk. First, the preproduction development period for a new mine is characteristically long. Under extremely favorable conditions, a significant mine may be developed in as little as two years, but the norm is four to six years or more. Second, mining is among the most capital intensive industries, consistently ranking near the top among all industrial sectors in assets per employee, and near the bottom in annual sales dollars per dollar of assets. Thus, mine investors typically have large sums invested for a long time before the outcome of the venture is determined by notoriously unpredictable markets. This is not a business for the faint of heart, and the importance of sound investment decision making is obvious. The high risk and technical complexity of mining operations have combined to require greater attention to financial evaluation by mining engineers than by most engineers in other specialties. Nearly all early mining engineering textbooks dealt with problems in mine valuation in a detailed manner; and, today, the sophistication of capital investment analysis is high in the mineral industries. Traditional Mine Valuation Methods Although some evaluation process has no doubt accompanied nearly every mine development throughout history, a formalized quantitative approach first emerged in the last half of the 19th century with the establishment of academic programs in mining engineering. The philosophy and approach to mine valuation that evolved at this time were, with periodic minor refinements, considered the standard for nearly a century. Only after 1960 did major changes begin to occur. The traditional approach to mine valuation reflected the investment community's historic attitudes toward risk. Mines were generally considered too risky for debt financing, and virtually every new mine was financed from internally generated funds or new equity subscriptions. The investment evaluation methods that evolved focused on mining's higher risk relative to other

Jan 11, 1982

By R. D. Auten

This paper is primarily a report on the process of using oolitic aragonite, as received from Marconi& Ocean Industries, Ltd. without further processing, for a major portion of the raw feed to a rotary kiln producing cement clinker. Oolitic aragonite is a high purity calcium carbonate material, dust free, with the appearance of a course, white sand. It is farmed when under the right conditions of temperature ocean currents, and ocean floor topography. The calcium carbonate will precipitate into small spherical particles on the ocean floor. These oceanic conditions are correct to cause precipitation of the calcium carbonate near Ocean Cay in the Bahama Island chain. The present growing deposit near Ocean Cay is in the billions of tons and is mined by a relatively shallow-operation hydraulic dredge. The aragonite thus formed is en orthorhombic crystaline form of calcium carbonate with a specific gravity of approximately 2.9. At a temperature of 505°C. (940F), the aragonite converts to the hexagonal crystal of calcite with a specific gravity of 2.6 to 2.7. This change in specific gravity weakens the structure of the particles but the individual pieces are still fairly hard. When the material is then calcined at 900°C (1650°F), the particles retain their shape but become soft and will break up under finger pressure.

Jan 1, 1978

By A. Wallace Mitchell

Barite deposits in Nevada occur as bedded and vein-types along a north-northeastern -trending zone which parallels the Antler orogenic belt The bedded deposits of Nevada are the most significant economically. They are presently supplying eighty-five percent of the domestic barite production which is used primarily as a weighting agent in the petroleum drilling industry. The ore bodies are controlled both structurally and stratigraphically, occurring along regional and local structural breaks in siliceous eugeosynclinal rocks of mid-Paleozoic age. Evidence for origin of the barite includes sedimentary and hydrothermal features indicating that localization probably took place along fractures in the seafloor.

Jan 1, 1980

By B. Tolwinski

Long-Term Open Pit Scheduler or L-TOPS is a new software package for evaluating, planning, and design of open pit mines. L-TOPS transforms geological, economic, and technical information about a mineral deposit into a detailed mining schedule that maximizes economic efficiency without neglecting the practical requirements of mining operations. L-TOPS has been customized for integration with Placer Dome Inc.'s existing in-house resource/reserve optimization software to function as a primary tool for property acquisition studies and for the designing of mines for feasibility studies. This pa-per presents an overview of L-TOPS and reports on its application to Placer Pacific's (Placer Dome's Australian affiliate) Mt. Rawdon project.

Jan 1, 1996

By Frederick P. Schwarz

Sample preparation and analysis can impose devastating errors on assay data. Minimizing these errors by testing and procedural redesign may be critical to assure representative assays and project success. Replicate samples, taken at any volume-reduction and/or analytical step in a sampling procedure, generate replicate assay values whose relative differences constitute a set of data. Variance of this data judges the addition to total sampling error imposed by the step generating the replicates. A variance more than (11.5%)' is excessive for a single step. Sample volume increase and/or comminution at a step will reduce variance for that step. Rejects from well mineralized intercepts can provide bulk samples for testing.

Jan 1, 1989

By Marcus A. Wiley, Gregory Abramov

Borehole mining (BHM) is a remotely operated method of extracting rock material through boreholes by high-pressure water jets. Figure 1 illustrates a BHM tool and fluids circulation. The tool consists of at least two pipes, one for pumping down high-pressure water, the second for delivering slurry to the surface. This article reviews the BHM process. It discusses current and new applications for borehole mining and help the readers determine if BHM is applicable in their situations. Previous articles in ME about BHM explained either a particular project (ME, April 2001, pp. 33-36) or a newest patent in this area (ME, March 1991, pp. 313-318). However, neither one provided an overview on the modern BHM technology.

Jan 1, 2004

By J. Kallioinen

Theoretical considerations, experimental results and plant experience have lead to a new design concept called the unit reactor approach. It has been successfully implemented to the largest flotation cell on the market, the 4000 cu ft OK TankCell. The work has also lead to a new operating idea called size specific flotation. The paper discusses these concepts in the view of full scale field experiments. In large scale porphyry copper flotation experiments conducted in Chile the new large TankCell with its new low energy input Free Flow mechanism out-performed the more conventional designs. The recovery was substantially better, especially in the coarse fractions. In some experiments the difference in total recovery was up to 10%-units and the savings in total energy consumption at the same time over 40%.

Jan 1, 1995

By Hal McVey

Introduction The role of marketing in the minerals and mining industry takes on different degrees of importance depending on the commodity, but nowhere are sales and marketing more important than in industrial minerals. This article compares industrial minerals marketing with the marketing of other mining and mineral products. Marketing in Mining Some broad generalizations on the marketing of industrial minerals in relation to other mineral products can be made without getting bogged down with exceptions to generalizations. Two totally different areas of mineral production are crude oil and natural gas, and metals, including ores and concentrates. Although these commodities are the basis for two completely different industries, they share two things in common from a marketing standpoint: • Their value per unit volume is usually high enough so that they can be transported great distances. • Their specifications are readily definable and, therefore, the quality of a standard product from a production run can be communicated by stating certain chemical and physical features. This permits sales to be consummated by telephone, telex, and letter, without the need to pretest the products under use conditions. In regard to the first item, industrial minerals, as opposed to oil, gas, and metals, are in most instances site specific. Location of the point of production in relation to the point of use is of paramount importance based on a generally lower unit to volume value. This means that transportation is a major factor, with the cost of getting the mineral to market commonly exceeding its f.o.b. value. Coal marketing has many characteristics in common with industrial minerals. Coal sales can es-

Jan 11, 1983

By Ning Wang, Tengfei Guo, Wanyan Li, Hanjie Wen, Hannian Gu, Zehai Li

Bauxite residue (red mud) is an alkaline waste derived from the industrial process for extraction of alumina from bauxite ore. Some bauxite residues contain considerable concentrations of critical metals, for example, rare earth elements. Lithium in red mud was also reported as a potential resource. In the current study, a Li-rich red mud was leached using acetic acid to investigate the leaching behavior of lithium followed by neutralizing with hydrochloric or oxalic acid. By neutralizing red mud using diluted hydrochloric acid (0.01 mol/L), 58.04–60.27% of lithium was leached using 25% acetic acid at 95 °C for 60 min. In the meantime, more than 95% of sodium and 85% of calcium were also dissolved in the leachate solution. While oxalic acid (0.5 mol/L) was used to neutralize red mud prior to acetic acid leaching, lithium performed lower leaching efficiencies (42.41–46.88%) in comparison of using of hydrochloric acid–neutralized red mud. Nevertheless, these leaching efficiencies of lithium were close to that of calcium and much higher than those of sodium under the condition. In this study, 25% (v/v) of acetic acid, at 85 °C for 60 min, was demonstrated as optimum conditions for lithium extraction from oxalic acid–neutralized red mud using acetic acid. The results would be useful and of interest for lithium recovery and purification from red mud.

By Anthony Edey, Leigh A. Readdy, Bruce A. Kennedy

Introduction Very little attention normally is given by the experts, or the public at large, to the fact that the majority of the oil that has been or will be discovered within the U.S. remains in the ground. The inherent limitations of oil production through surface wells, either by primary or secondary techniques, will result in a total of over 300 billion bbl of oil left in the ground after completing production by standard petroleum techniques in currently producing or producible fields. This reserve represents some two-thirds of the original quantity of oil discovered in place. Recent work by a number of groups has shown that there is strong economic justification for extracting this remaining oil by mining and processing techniques. Table 1, taken from 1977 API reports, demonstrates the oil left in place at the end of the conventional petroleum production cycle in then-known fields within th’e U.S. Possible targets for oil mining operations include (1) oil remaining in place in fields and pools that have reached economic depletion by current petroleum production methods and that are not amenable to economic recovery by conventional petroleum industry techniques; (2) oilor bitumen-saturated rocks not normally considered by the industry to constitute producible reservoirs, such as shales and diatomites; and (3) asphalt- and bitumen-impregnated rocks. Economically Depleted Fields A more detailed examination of the depleted fields shows that estimates of oil remaining in place after primary, secondary, and nondestructive tertiary recovery can vary widely. There is significant evidence, however, that more than half the estimated original oil in place (OOIP) remains in the reservoir after all petroleum extraction techniques have been applied. If one compares the sum of past oil production and estimated remaining producible reserves with the API estimate of total discovered OOIP as of 1975, it becomes apparent that for the U.S. as a whole, 67070of the 00IP will remain in place at the end of the

Jan 1, 1980

By Anthony Edey, Leigh A. Readdy, Bruce A. Kennedy

Introduction Very little attention normally is given by the experts, or the public at large, to the fact that the majority of the oil that has been or will be discovered within the U.S. remains in the ground. The inherent limitations of oil production through surface wells, either by primary or secondary techniques, will result in a total of over 300 billion bbl of oil left in the ground after completing production by standard petroleum techniques in currently producing or producible fields. This reserve represents some two-thirds of the original quantity of oil discovered in place. Recent work by a number of groups has shown that there is strong economic justification for extracting this remaining oil by mining and processing techniques. Table 1, taken from 1977 API reports, demonstrates the oil left in place at the end of the con¬ventional petroleum production cycle in then-known fields within the U.S. Possible targets for oil mining operations include (1) oil remaining in place in fields and pools that have reached economic depletion by current petroleum production methods and that are not amenable to economic recovery by conventional petroleum industry techniques; (2) oil-or bitumen-saturated rocks not normally considered by the industry to constitute producible reservoirs, such as shales and diatomites; and (3) asphalt- and bitumen-impregnated rocks. Economically Depleted Fields A more detailed examination of the depleted fields shows that estimates of oil remaining in place after primary, secondary, and nondestructive tertiary recovery can vary widely. There is significant evidence, however, that more than half the estimated original oil in place (OOIP) remains in the reservoir after all petroleum extraction techniques have been applied. If one compares the sum of past oil production and estimated remaining producible reserves with the API estimate of total discovered OOIP as of 1975, it becomes apparent that for the U.S. as a whole, 67% of the OOIP will remain in place at the end of the

Jan 9, 1980

Coal has been mined in the central Appalachian coalfields of southern West Virginia, western Virginia, and eastern Kentucky for more than a century. The dwindling reserve base consists in large part of coal that would have been considered unmineable by earlier generations. Nearly every current operation is working on a property where coal has been extracted in the past, from seams either above, below, or both. NIOSH is conducting research aimed at helping mine planners prevent hazardous conditions due to multiple seam interactions. To-date, more than 300 case histories have been collected from underground mines, mainly from central Appalachia. This paper focuses on several of the more challenging situations that have been encountered, including: • Room-and-pillar development 20 ft (6 m) beneath full extraction workings at a depth of 1,000 ft (300m) of cover (Virginia) • Pillar recovery 45 ft above full extraction workings at 900 ft (270 m) of cover (Virginia) • Near-simultaneous room-and-pillar mining with pillar recovery with 40 ft (12 m) of interburden and 1,500-2,000 ft (450-600 m) of cover (Kentucky) • Longwall mining directly beneath main entries in overlying seams (West Virginia) • Some of these operations have been highly successful in overcoming the challenges, others less so. The lessons learned from their experience will help ensure that these and similar difficult reserves can be mined safely.

Jan 1, 2006

In phosphate flotation, more than 90% of the finer fraction (-35, + 150 mesh) is recovered as opposed to 70% of the coarser material (-16, + 35 mesh). On the other hand, coarser fraction is higher in phosphate content than the finer feed. Consequently, improvement in the coarse recovery is highly desired. It was determined on bench scale that emulsification of the collector (fuel oil and fatty acid mixture) can lead to enhanced recovery of coarse particles. Flotation of phosphate with emulsified collector resulted in improved recovery and grade also on the plant scale.

Jan 1, 1992