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By Steven Hoerger

Newmont Mining has a large, integrated gold-mining operation in northern Nevada with several mines, stockpiles and processing facilities. There are more than 90 defined metallurgical ore types and more than 60 defined gold-recovery process options. Newmont developed a mine plan and process model to take better advantage of the available synergies at its Nevada mines. This plan includes a mixed integer and linear programming optimization tool. This system is maintained and operated by a Nevada planning group. Standard in-house planning software tools and methods have been implemented at all mine sites. These changes have allowed a reduction in mine engineering staff and have increased the effectiveness of mine planning.

Jan 1, 1999

By R. J. Watson, A. H. Juch

About half a million sucker-rod pumps are installed in oil wells in the U. S. alone. In Venezuela, too, the system is widely used; some 5,000, or 90 percent, of Cia. Shell de Venezuela's wells produce a total of 400,000 BOPD by this method. Most of the crude pumped is viscous, gassy and contains relatively small amounts of free water. API gravities vary from 90 to 16O; dead oil viscosities vary from 10 to 10,000 cp at the pump; and GOR's range from 100 to 2,000 cu ft/bbl. Pumps are set at depths ranging from a few hundred to 6,000 ft; the average setting depth is about 2,500 ft. From the literature, it appears that although recent years have seen significant progress toward understanding the rod pumping system as a whole, relatively little attention has been paid to those key items, the sucker-rod pump and the subsurface gas separator or gas anchor. Perhaps because of proration in the U. S., pump manufacturers have seemingly concerned themselves more with the durability of their product, achieved mainly through robust design and metallurgical know-how, than with its working efficiency. In 1963, CSV commenced a major rehabilitation and expansion of its heavy oil fields along the Bolivar Coast. The advent of the more efficient gravel-packed completion and of large-scale thermal recovery (mainly steam soak) operations resulted in well potentials *Now with B. I. P. M., The Hague, The Netherlands. greater than pump capacities. Hence, an urgent need arose to improve over-all pump efficiencies and to attack those special problems related to the production of both the extremely viscous and the hot, steam-laden crudes that formed an increasing proportion of the total stream. There followed a detailed investigation and testing program, carried out in close cooperation with a major pump manufacturer. This culminated in the introduction to the oil industry of a new line of sucker-rod pumps. Early Investigations and Experiments Field Tests Extensive field tests were carried out in three primary Bolivar Coast wells with an in-situ dead oil viscosity ranging from 400 to 6,000 cp. In these installations provision was made to (1) monitor bottom-hole pressures below, in and above the pump by means of pressure transducers, and record casing- and tubing-head pressures continuously; (2) measure accurately the annulus gas, as well as measure the tubing gas and liquid production from the well; (3) take special PVT samples of the well fluid; (4) measure power consumption of the prime mover; and (5) measure the rod loads at the polished rod. A typical test installation is illustrated in Fig. 1. It was established from the pressure transducers that with viscous oils, there is considerable flow resistance across the pump and gas anchor assembly. Pressure surges were observed over each pump cycle,

Jan 1, 1970

By D Syme

In the middle of 2000, BHP Billiton implemented a Six Sigma Plus business improvement program known as Operating Excellence. It was developed based on a business bottom line initiative to deliver 35 - 40c/share and was one of the BHP Billiton strategies to deliver $2 earnings per share and a longer term $40 share price (BHP share price). Cannington is a silver, lead and zinc mine owned and operated by BHP Billiton. Through implementing Six Sigma Plus Cannington wanted to:have in-house capabilities to change and improve; tailor for the needs of each business unit and department; have æSharing of its KnowledgeÆ as a tool for improvement and have a competitive edge across Cannington û to be better than our competitors; learn from and leverage off the successes of improved safety and prior business improvement efforts; and ensure networking and sharing of information have common measurement systems across all assets. As with most business improvement programs û Six Sigma Plus was met with some degree of skepticism, especially given the amount of resources involved. After 18 months, much of this skepticism has been replaced with enthusiasm as peopleÆs understanding and acceptance of its fundamental concepts are being realised. The idea behind Six Sigma Plus is that it combines sound technical solutions with high acceptance by those who need to work with or implement the change. The future vision for Six Sigma Plus is that it become part of what we do at Cannington û just like safety and environment û so that Six Sigma tools and methodologies are used in our every day work.

Jan 1, 2002

Tunnelling under squeezing ground conditions poses significant challenges. There are fundamental differences in the choice of support for mining as opposed to civil engineering. This paper reviews ground support strategies that have been used to control large deformations in mining excavations based on field data from five different mines in Australia and Canada. Recommendations are made for improved ground control strategies in squeezing rock conditions.

Jan 1, 2008

By A D. Campbell, G R. Power

The objective of the draw strategy in a caving mine is to maximise economic return by minimising waste dilution3 and maximising ore recovery4. The draw strategy must also include suitable controls for air blast and mud rush hazards and is highly constrained until continuous cave propagation has been achieved. This paper details a three-year project at the Ernest Henry Mine (EHM), which used cave flow simulation software to develop a draw strategy that increased the mine value by 32 per cent.Dilution and ore loss can be significant in sublevel cave (SLC) operations and result in poor recovery and considerable economic losses. To minimise dilution and ore loss, cellular automata software was used to simulate cave flow over the mine life. The optimisation project required mining footprints for various cut-off grades to be developed. Draw strategies for each mine footprint were then generated using a range of shut-off grades. Economic assessment of each scenario was then conducted to determine the mine footprint and corresponding draw strategy that generated the highest NPV (net present value). The iterative simulation process was improved by developing automated software functions in the flow modelling software to reduce time taken to generate and assess life-of-mine (LOM) draw strategy scenarios.In addition to improving the NPV of the mine, the optimisation project also enabled a decrease in the mine cut-off grade which increased the ore reserve and extended the mine life. Overall, an iterative process of mine planning, cave simulation, economic evaluation and geotechnical analysis was used to significantly increase the economic return of the SLC whilst ensuring caving risks were controlled to an acceptable level.CITATION:Campbell, A D and Power, G R, 2016. Increasing net present value by a third at an operating sublevel cave mine using draw strategy optimisation, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 167–174 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By C. Fairhurst

Most of the papers designated as being within the topic of underground storage at this Symposium are concerned with aspects of radioactive waste isolation. Although this is, unquestionably, an important international application of underground storage, and one involving a considerable number of research investigations, the subject of underground storage is indeed much broader. Several major international conferences have been devoted exclusively to it. Applications include storage, under a range of temperatures and pressures, of oil and liquefied petroleum products, compressed air, heat, foodstuffs of various kinds, hazardous and 'nuisance' industrial by-products, and a variety of special applications, both civilian and military - some in use, others proposed. Storage may be in caverns excavated specifically for the purpose, exhausted mines may be adapted for storage or, in some cases, the material to be stored may be injected under pressure into the pore spaces of porous-permeable formations at depth. A variety of rock types and geological environments are used, e.g. excavations in salted or domal salt, where long-term creep closure of the openings is a concern; massive granite, where fluid loss through fissures may be important. Cavities may have spans of several tens of meters, and there is interest in achieving still larger excavations. As would be expected, this breadth of underground storage applications introduces a similarly broad range of questions in rock mechanics and rock engineering. The report will review these questions and recent developments in rock mechanics research, computational procedures, and design applications - and will also discuss the opportunities for a still greater range of applications of underground storage to current industrial and social problems.

Jan 1, 1989

By V. B. Dale

This report is one of a series covering the mineral resources of the Nation. It briefly describes most of the known tungsten deposits in Gila, Yavapai, and Mohave Counties, Ariz. Many of the descriptions are taken from the reports of previous examinations by Bureau of Mines engineers, and from Defense Minerals Exploration Administration files. Where a previous examination had been made, and an inquiry disclosed that little or no work had been done since that time, pertinent information from the report was used in this paper with acknowledgment of the source. However, the majority of the descriptions is from field examinations by the author. In the past 3 years (July 1956-May 1959) only necessary annual assessment work was conducted on nearly all the properties described in this paper. There was no active mining on any of the properties examined.

Jan 1, 1961

By Kenneth H. Johnston

The Weber pool in Washington County, Okla. (fig. 1), covers an area extending from 2 miles east and slightly north of Bartlesville, Okla., to a point approximately 2-1P tiles northeast of Dewey, Okla. The pool is a part of the area designated by the Standing Committee on Oil Field Nomenclature, Kansas-Oklahoma Division, Mid-Continent Oil & Gas Association, as the Bartlesville-Dewey field. In the following discussion of the geology, development, and exploitation of the Weber pool, the writers, by means of structure maps, cross sections through various parts of the reservoir, and tabulated development data and production statistics, have recorded salient information on a field that was developed before .1910 in an Area that has been repressured since 1926. The total oil production to January 1, 19.0., from the 2,639 developed acres considered in this report, was approximately 14 million barrels, or a recovery of about 5,3;2 barrels per acre, or 227 barrels per acre-foot. The production of the estimated 18 million barrels of recoverable oil remaining in the Bartlesville sand reservoir will require the initiation of additional secondary-recovery practices on some of the leases and the application of a more systematic repressuring program on others.

Jan 1, 1950

By Sheridan J. Rodgers

Improved methods of dust control in the metal and nonmetal mining industries were studied. Preliminary dust surveys were made at selected mines and three mines were chosen for additional studies. Dust control effectiveness was evaluated using full shift gravimetric sampling and GCA Dust Monitor readings. Analyses for free silica content and particle size distribution were conducted. A belt washing system which was used to control dust at a transfer point was evaluated. The average reduction of respirable dust was 48% and the average reduction of total dust was 78%. The belt washing system not only maintained the work place within compliance but reduced maintenance problems along the beltway by 90%. Exhaust ventilation at a crusher was evaluated for control effectiveness. Ventilation along with operation of the crusher control room under slight positive pressure, maintained the work place within compliance. An exhaust ventilation system was designed for use at an underground rotary dump. Although the system was not installed or evaluated, details on the design are given. High expansion foam was used at an ore chute in an attempt to control dust at the draw point and loading point. Results indicated that foam did not effectively control dust.

Jan 1, 1978

By Robert B. Kistler, Ward C. Smith

The borate industry is one of the few sectors of the mining and mineral-processing industry which the United States still dominates. Since about 1927, the United States has supplied over half of the world's total boron and borate raw materials, and many of the chemical derivatives as well. Chiefly responsible for this record are companies producing sodium borates from two large deposits in southern California, at Boron (Kramer) and Searles Lake. The sodium borates, or products derived from borax and borax-containing brines, are the preferred borates for industry because they are soluble in water and combine readily with most other chemicals. Calcium borates (or sodium-free compounds) are required for certain end uses, but in general, nonsodium borates are used only where borax is not avail- able. During the past hundred years, the use of boron compounds throughout the world has risen from a few tons per year to the equivalent of about a million tons of B2O3. Leadership in supplying borates has shifted from country to country and from region to region during this period, generally as the result of the development of newly discovered deposits that were better in quality, more accessible, or more economically exploitable than previous sources (Table 1). Primary Products and End Uses The principal borate products offered by primary producers in the United States are listed in Table 2. In general, these products are utilized worldwide by almost all consumers, regardless of the original source of the primary borates. In the United States, the primary borates all originate in southern California. Colemanite is produced as crude or processed crude ore from the Death Valley area and is utilized by the fiber glass and ceramic industries without further treatment. Production from Searles Lake, Calif., is from brines that are processed in chemical plants where borax and other compounds are recovered and the principal borate products are produced. At Boron, Calif., the world's leading producer is mining a deposit of mineral borax and operating a chemical refinery. The mineral borax is mined together with included clay, and refined borax or "lo-mol" is one of the refinery products. The mineral and the chemical compound are identical, Na2B4O7- lOH2O. In addition to ship- ping all major refined borate products from Boron, the company ships semiprocessed ore concentrates to treatment plants elsewhere.

Jan 1, 1975

By H. Miller

In recognition of the need for a portable low-profile hard rock crusher, the Bureau of Mines sponsored the development of such a unit capable of moving up as the face advances. By allowing primary ore reduction at or near the mine face, the advantages of conveyor haulage From the face as demonstrated in soft ore and coal mines, could be realized for hard rock Brines as well. This report presents the results of a development and testing program for such a portable low-profile crusher, designed by Eagle Crusher Company and called the M44. The unit has an extremely low vertical profile considering its size and capacity. The crushing jaws, which form the crushing lumber, are inclined, with the lower jaw mounted for eccentric movement relative to the stationary upper jaw. This provides efficient crushing while also forcing material through the crushing chamber. As a result, the inlet feeder can be disposed horizontally. To facilitate correct processing of different materials, the size of the discharge opening and the action of the movable crushing jaw are variable. The unit also incorporates a feeder hopper and discharge conveyor that provides for efficient ore handling through the machine. Tests demonstrated the M44 Crusher's high capacity, efficiency and reliability. During testing, it crushed over 120,000 tons of materials of up to 32,000 psi compressive strength at production rates in the 200-350 tons/hour range. The unit operated smoothly under simulated low-headroom conditions, and Proved readily transportable.

Jan 1, 1983

By Bratt G. C

When zinc is electrowon from concentrates or residues of high manganese content, the zinc sulphate electrolyte may contain high levels of manganese. The manganese level is usually controlled by removal of manganese at the anode as the dioxide during the zinc electrodeposition stage.By increasing the temperature of an electrolyte containing 8 gll manganese from 35°C to 90°C, decreasing the acidity from 100 gll to 30 gll, reducing the current density from 432.A.m-2 t6 286 A.m-2 and using new lead anodes containing over 0·75 per cent silver, the current efficiency for manganese dioxide removal was .increased from less than 1 per cent to over 20 per cent.At the same time the current efficiency for zinc deposition was maintained above 90 per cent by additions of high molecular weight cationic polyacrylamides to the cell. By utilization of these conditions in a small number of cells, the manganese level in the circuit could be economically concrolled to any desired level.With these conditions the formation of the dioxide changes from an indirect route, via Mn04-, to a direct oxidation of Mn2+ to Mn02.The incorporation of impurities such as Pb, K, NH4, Cu, Ni, or Fe makes the deposit unsatisfactory for direct use in Zn - Mn02 dry cells. The deposit structure changes from cryptomelane at low temperature to y3-Mn02 at high temperature.

Jan 1, 1975

By I. Liebman

A Bureau of Mines study is in progress to determine the effectiveness of passive water barriers in suppressing coal-dust explosions. A 2.9-ft3-capacity water-filled plastic tub was found effective in suppressing dust explosions propagating at speeds of 250 to over 1,000 ft/sec. Work directed at determining the limitations of water barriers showed that the passive water barrier technique is also feasible for the suppression of weak dust explosions propagating at speeds of 100 to 250 ft/sec. For relatively slow accelerating flames, dynamic wind forces appear to be the important quantity governing fragmentation of the plastic tub and subsequent water release and dispersion, whereas dynamic impulse appears to be the significant quantity for rapidly accelerating flames. The acoustic approximation (relation between static pressure and flame or wind speed) is shown to be valid in a long single mine entry. This relationship appears to be useful in predicting the regions within a long single entry where passive water barriers are effective in quenching a dust explosion.

Jan 1, 1974

By L. F. Elkins

Water coming into wells with bottom water present in the Fosterton field, when their oil recovery was only 0.1 to 1.5 per cent of oil in place below the lowest perforation, confirms lack of shale barriers to vertical flow which also are not apparent in cores and electric logy. Low contrast of vertical and horizontal permeability, high mobility ratio betweerz oil and water zone and pos.rible rate effects due to gravity Combine to prevent easy analysis of water invasion pattern and efficiency by analogy or intuition. Theoretical analysis of performance including these factors using a new direct nurnerical .solution of potential distribution in a network led to unanticapted indications that water would under-run the entire oil reservoir with low volumetric coverage if supplied through natural influx or peripheral water injecfion below the oil-water contact. An unusual pattern of water injection is to he adopted in this recently unitized pool to provide more uniform water flooding in that two-thirds of the oil reservoir not underlain by bottom wafer. INTRODUCTION The Fosterton field, Southwestern Saskatchewan, Canada, was discovered in Jan., 1952. It produces at a depth of 3,100 ft from a pinch-out of the Roseray sand at the Lower Cretaceous-Jurassic unconformity. The field, covering 2,500 acres, contains 54 wells on 40-acre spacing. Development was essentially complete in June, 1954, but significant production did not start until May, 1955, when a pipeline outlet became available. Within one year rapid in- creases in gas-oil ratio and early encroachment of water created operating problems in the down-structure eastern half of the field and raised serious questions about reservoir performance and ultimate recovery. This paper describes the unusual behavior of water encroachment—on both well and reservoir bases—and the analyses made to interpret it. The field was unitized July 1, 1958, for water flooding. A somewhat unconventional

By D. H. McCain

Through a unique partnership between the Colorado Mine Safety and Training Program (CMSTP), the Colorado Rock Products Association (CRPA) and the Higher Education and Advanced Technology (HEAT) Center, a video packed, dazzling CD-ROM training program was developed for new miners entering the aggregate industry. Why this product was developed, and why the aggregate industry, will be discussed along with the challenges faced throughout the project. Cooperation from every one involved including MSHA made this the product of which all other training materials in the mining industry will be measured against in the 21st Century. This product's versatility and wide application makes it a tool that is as critical to a mine's success as any earth moving machine. Developed with both state and federal grant moneys allows this product to be affordable to small operators and independent contractors. The quality of this two CD-ROM set rivals any commercially made CD-ROM training.

Jan 1, 2001

By E. G. Davis

The Bureau of Mines investigated gaseous direct reduction of low-grade iron ore concentrates in a continuous fluid-bed reactor. These studies were made in a 4-inch diameter fluid-bed reactor using hydrogen alone, and oxygen-or air-reformed natural gas as the reductants. The percent reduction is directly dependent on the mole ratio of hydrogen in the reducing gas to the oxygen associated with the iron oxide in the ore. Two-and three-stage fluid bed tests were simulated by repeated continuous tests. The results showed that percent reduction of the final product was dependent on the mole ratio of the quantity of hydrogen in the gas of each stage to oxygen in the iron oxide of the initial ore feed. Reduction as high as 87 percent in the single stages and as high as 94 percent in the multistages was obtained when either hydrogen or reformed natural gas was used as the reducing gas. Magnetic separation and concentration of the highly reduced fluid-bed product yielded a high metallic iron concentrate analyzing 85 percent total iron and 80 percent metallic iron with total iron recovery as great as 90 percent. Agglomeration of the high-grade metallized concentrate produced hard pellets analyzing 85 percent total iron and 78 percent metallic iron. Green pellets, with good strength, were made without any binder in a drum pelletizer. Direct melting of the high-metallic fluid-bed product in a basic lined arc furnace produced a nearly pure iron which contained 0.09 C and 0.01 P with 95 percent recovery of the metallic iron in the metal.

Jan 1, 1972

By W. Abdellah

The purpose of this paper is to establish a qualitative method to estimate the risk level (e.g. rating and ranking) resulting from mining activity. Risk is the product of two factors: probability of failure and cost of consequences. A resultant assessment scale matrix is then used to assign a risk index value which is directly proportional to the potential for excavation instability. A case study, the No. 1 Shear East orebody at Vale?s Garson Mine in Sudbury, Ontario will be examined. A three-dimensional, elastoplastic, finite difference model (FLAC 3D) is presented for a mine development intersection situated 1.5 km below ground surface. The developed assessment scale matrix is used to estimate risk index for intersection (2981) located on 5000 level. The results are presented and categorized with respect to risk-index value, probability of instability, cost of consequence, and mining stage.

Jan 1, 2014

By M. John Brodie

This report reviews the regulatory environment as it pertains to waste rock management and disposal from mining operations, excluding coal and placer gold operations, in the \irate of Alaska. It is based on the EPA's staff position on an effective program to regulate mining waste as presented in the May, 1990 Strawman II document. The unique conditions which occur in pans of the state, including a fragile environment, high seismicity and permafrost, are identified. The special waste management practices which are necessitated by these conditions are delineated. The report provides a detailed outline of the current technologies that are suitable for designing, constructing, operating and closing a waste rock facility to meet environmental protection objectives. Cost implications to the mining industry of potential regulatory actions, such as the degree of groundwater protection, are examined.

Jan 1, 1992

THE Yallourn chimney has aroused interest, as it is, for the time being, the tallest structural erection in Australia. Its height was not decided on, however, with the object of breaking records, but is purely incidental to the purpose which it serves. Theboiler plant at the briquetting works (first instalment) consists of five Babcock and Wilcox land-type water-tube boilers, each of 4510 sq ft. heating su:r£ace and 225 sq. ft. grate area in the form of step grates. Four boilers will normally produce 73,000 lb. of steam per hour at a gauge pressure of 265 lb. and a temperature of 6500 F., the fifth boiler being a reserve. Each boiler will consume about 100 tons of Yallourn coal per 24 hours. Provision is made for future installation of economizers, should it be found desirable. Designing for this condition, and allowing for a waste gas temperature of 3500 F. and an air temperature exceeding 1000 it was found necessary to have a draft of about 1.3 in. (water gauge) at the base of the chimney, and to deal with about 2000 cub. ft. of gases per second. Estimates were made of the cost of providing the necessary draught by means of fans and by means of a tall chill).ney. The annual charges of the two methods differed only slightly, and the tall chimney wasselected as being the more general practice in briquetting factories.Estimates were prepared for brick and concrete chiIlllleys. Yallourn bricks at that time were hand-made, and, while very suitable for domestic work, were not capable of withstanding high compressive stresses. The chimney design to suit these bricks thus required to be on very ample lines, resulting in high cost. Machine-made bricks from Melbourne would cost about £5 10s. per thousand on the site, with extra for radials, so that high cost again resulted. On the score...

Jan 1, 1924

By Terry S. Cory

This report describes the results of a measurement and analysis program to characterize wireless radio transmission In metal/non-metal mines over a wide frequency range from 0.2 -1000 MHz and over a variety of mine environments. Six mines were chosen based on the relative economic significance of their product to the U.S. economy. Mine types Include 01 f shale, uranium, potash, lead/zinc, copper, and silver. Particular mines were chosen so that the group would embody the most Important mining techniques. The results show that transmission at medium frequencies are optimum tor wireless mine communications, In agreement with extensive testing previously performed by the authors in coal mines, and that mine-wide wireless systems are feasible with a minimum requirement for new dedicated wiring. At least one need for such a wireless system was identified in each mine visited.

Jan 1, 1981