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By P. B. Grote

The report is concerned with the issue of the possible transfer of U.S. and other developed country deep ocean mining (DOM) technologies to developing countries. This subject is one of several major issues in current UN Law of the Seas negotiations. As background to the subject, the report provides a detailed critique of the various terms and conditions pertaining to technology transfer in recent negotiating texts. It also provides a description of the relevant DOM technology, sources of innovation, and methods of proprietary protection. Functional requirements for viable technology transfer are developed and used as a basis for the definition of alternative levels of programs and implementation approaches, including required changes in the negotiating text. The consequences of these technology transfer options on the various parties are investigated.

Jan 1, 1978

By T. J. Kolokoto

This paper is based on a project conducted at Khomanani 2 shaft, Anglo American Platinum Limited. The main objective was to find an alternative support element in stopes to address the falls of ground (FOG) problem experienced at this shaft. Literature review was the major method used in the investigations. Resin bolts or any 1.5 m in-stope roofbolts were considered. The shaft was making use of 0.9 m long friction bolts, and these could not prevent the FOG experienced. Observations indicated that the FOG resulted in fall-out thicknesses averaging to 1.1 m, which is greater than the supported length of the friction bolts. The implementation of 1.5 m long bolts was recommended as a result of the project. These bolts will be able to address the fall-out thickness and provide sufficient support resistance to mitigate FOG. The chosen support element will result in a relatively small increase in support costs.

Jan 1, 2013

By S. J. Schatzel

In order to better understand the effects of longwall mining on the methane reservoir overlying the panel, the National Institute for Occupational Safety and Health/Pittsburgh Research Laboratory (NIOSH/PRL) designed and implemented a vertical borehole monitoring experiment (BME) on an active longwall panel. The mine operates in the Pittsburgh Coalbed in Greene County, Pennsylvania. The BME site was located away from either end of the panel to avoid mechanical influences caused by the draping of overburden in this region and was positioned at the same distance from the tailgate gateroad as the mine?s gob gas venthole sites. The borehole drilling depths and monitoring intervals were chosen to address a different stratigraphic zone in each of the three planned holes. The monitoring boreholes were positioned perpendicular to face advance using a close spacing pattern of about 15 m (50 ft) between collars. Boreholes were instrumented downhole and on the surface for various measurements. It was observed from the field data that the gob gas venthole fracture network formed 24-46 m (80-150 ft) ahead of the mining face. Overburden permeability?s within the same test zones increased 100 to 500 times following undermining. The borehole test interval within the fractured rock responded to overburden gas pressure while the test interval in the caved zone responded to mine ventilation conditions. Eight months after the boreholes were undermined, slug testing indicated permeabilities had increased further in the fractured rock zone. Measurements of surface movement indicate that the permeability development observed in the boreholes is a product of vertical subsidence without lateral movement within the tensional rock mechanics zone on a supercritical longwall panel. Results from this study suggest that maximum permeability in the longwall panel overburden is achieved 58 to 190 m (190 to 620 ft) behind the longwall following maximum compaction of the overburden.

Jan 1, 2009

By T. Belem

The main objective of this study is to better understand the effect of underground CPB placement conditions on its microstructural, hydro-mechanical and geochemical properties. To reach this objective, three PVC columns, each 3 m high, were built, and were filled with CPB material. The columns allow simulating undrained (UD), half-drained (HD) and fully-drained (FD) conditions along with the measurement of resulting self-weight consolidation settlement of the CPB. Bleed and drainage waters were also collected from each column for geochemical analyses (pH, Eh, EC, SO42- content). After 90-days of curing time, a total of sixty CPB samples were cored from the backfill columns and subjected to uniaxial compression tests followed by physical characterization (Gs, void ratio, water content, degree of saturation, specific surface area). The results showed that the total drainage water and the maximum observed settlement occur mainly within the first 72 hours after the columns are filled. The corresponding volumetric strains suggest that in situ backfilled stopes simulated behave in a similar way to the fully-drained (FD) or the half-drained (HD) conditions. The MIP test results show that the pore structure varies between the top and the bottom of each column.

May 1, 2007

The Framework Convention on Climate Change (FCCC) places serious obligations on New Zealand as a signatory nation. This paper examines the nature of the FCCC, New Zealand 's proposed policy response, and the.implications for the minerals industry.

Jan 1, 1994

By C. W. Morris

The continuous miner training system provides classroom materials training aids, and a continuous miner simulator to provide a short, intensive instruction and skills development program for training or retraining continuous miner operators. This project included refinement of training objectives, revision of training aids, improvements to the simulator, and evaluation of the entire system. This report describes the revised classroom materials and the validation of the training system.

Jan 1, 1982

By A. R. T. Denues

"INTRODUCTION The Explosives Division of the Bureau of Mines, United States Department of the Interior, is investigating cushioned blasting at the Explosives Testing Station, Bruceton, Pa. The general interests of this investigation are practical and relate particularly to safety. The immediate concern is an application of cushioned blasting in coal mining.In cushioned blasting, various means are employed to reduce the intensity of the application of energy in an explosive action in a borehole. The primary object is to increase the efficiency of the use of explosives. Cushioned blasting is designed to save the energy usually lost in excessive shattering and in this way to effect economies and to produce increased proportions of desirable lump coal. That this saving should lead to greater efficiency is indicated by an analogy with the theory and experience of size-redaction by crushing or grinding from which it is known that a large proportion of the energy consumed is expended in producing the smaller sizes (26),3/. Aside from these considerations, increasing the yield of lump coal is important in practice because larger sizes of coal usually sell at higher prices. Some statistics published in England in 1934 (63) illustrate the economic origin of the interest in increasing yields of lump coal; these indicate for three sizes of coal that as the size decreases the value decreases in the approximate series 3:1.5:1, thus:"

May 1, 1940

By P. Quinn

"The Venturi-aerated flotation column (VAC) is based on a reactor and separator design for a new generation of flotation machines. The reactor is a Venturi tube, where the air/slurry contact takes place with intensive aeration for efficient particle collection. The separator is a column of 1-3 m length that provides quiescent hydrodynamic conditions for effective separation of bubble-particle aggregates from the remaining slurry.Aeration in the Venturi tube occurs via two mechanisms: air dispersion and nucleation (cavitation). By forcing air through a restricted passage with a fast flowing slurry stream, air is dispersed into fine bubbles. Bubble formation due to cavitation occurs on the surface of particles in the low-pressure section of the Venturi, from dissolved air contained in the liquid.Size-by-size recovery and flotation rate constants were determined for a small-scale laboratory Venturi-aerated flotation column. The results were compared to those obtained in a laboratory 2.2 L Denver cell. It is shown that the Venturi-aerated flotation column has slightly slower flotation kinetics to the Denver cell, but with much higher flotation selectivity. A portable Venturi-aerated flotation column can effectively be used to investigate process or equipment problems in operating plants.INTRODUCTIONFlotation processes can generally be divided into two sub-processes: 1) selective collection of hydrophobic particles by air bubbles and 2) separation of bubble-particle aggregates from hydrophilic particles that remain in the pulp. The methods of aeration, or bubble generation, control the mechanism of particle collection by either collision with, and subsequent attachment to bubbles, or by in situ bubble formation on the surfaces of hydrophobic particles. A flotation device should provide optimal aeration conditions for efficient particle collection and a suitable hydrodynamic environment for effective removal of bubble-particle aggregates from the remaining pulp."

Jan 1, 2002

By John Yenter

"Unique blasting problems during reconstruction and expansion of 100 year old buildings toaccommodate gambling. Located on steep mountainous terrain and linked by narrowroadways, the towns of Central City and Black Hawk challenged blasters to exceptionalmeasures in order to control over_break, vibration, public exposure and damage to thecharacter of these historic mining towns. Utilities were also upgraded to fit demands of asmuch as 800% volume change in one year."

Jan 1, 1993

In exploiting the ultra-deep, narrow reef ore bodies of the Witwatersrand, the ventilation and cooling systems within the stopes play a critical role because of high concentrations of active workers. This paper examines the heat, ventilation and cooling effects of a number of different stoping layouts for narrow reef mining in ultra-deep operations in very hot rock. The stope ventilation and cooling needs are driven primarily by the difference between the air temperature and that of the rock front being excavated. These needs depend on the face utilization, geometry, face advance (rate and direction), layout, backfill, use of water and machinery1,2,3. Detailed studies of different stoping configurations have been undertaken for mining operations extending to depths of 5000m below surface, where virgin rock temperatures approach 70°C. Extensive work has been completed with regard to evaluating ventilation and cooling requirements to maintain air reject temperatures of 28°C wet-bulb and better. This knowledge is being used to determine overall cooling requirements, reduce operational costs and maximize the efficiency of cooling systems. These issues are important when considering both the local and regional air conditioning systems and the most effective application of in-stope chilled water.

Jan 1, 2001

The commercial development of the shallow (2200 ft2 400 ft) Windalia sand reservoir at Barrow Island provided the opportunity to conduct an intensive drilling programme using equipment and techniques designed for optimum performance.During the initial exploratory and reservoir delineation phase, 12 specific Windalia test wells were drilled using drilling equipment with an optimum depth range of 6QOO ft - 8000 ft and a 9 5/8 in by 7 in. casing programme was employed. The average time from commencement of move-in to rig release exclusive of coring for five representative wells was 187 hr during this phase.Development drilling commenced December 1966 with one rig, with the second in operation January 1967.As of January 1 1968, 168 development wells had been completed. The two rigs employed are drive-in units equipped with a telescoping .gelf raising doubles mast.Optimum depth range with 4 1/2 in. drill pipe is 2500-4000 ft. Casing programme is 8 5/8 in. by 5 1/2 in. Efficient performance was achieved immediately. The average time from commencement of move-in to rig release for 15 wells drilled early in the development programme was 99 hr.By application of experience and further modification of techniques, performance was improved to an average time of 72 hr per well for 15 wells recently completed.The major drilling problem on Barrow Island is surface hole drilling due to the very hard surface limestone combined with complete loss of circulation at sea level.In this operation, significant improvements have been effected. During the exploratory phase drilling, 12 1/4 in hole to set 9 5/8 in. casing, average penetration rate was 23 ft/hr. At the commencement of the development programme penetration rate, drilling 10 5/8 in. hole to set 8 5/8 in. casing, was 28 ft/hr for the 15 early wells considered, improving to 55 ft/hr for the 15 recent wells considered.This programme is a team effort and much credit must be given to the enthusiastic co-operation of the two drilling contractors.The current field record is 2 days 4 hr with a 4 1/2 hr move including the drilling of mousehole and rathole.

Jan 1, 1968

By Francis E. Federspiel

Silver and gold are the principal metals in the study area; they occur in quartz veins or silicified portions of shear zones. In some deposits, lead, antimony, zinc, and molybdenum are associated with gold and silver. A uranium-bearing buried stream channel lies near the southern boundary. Since 1850, more than 300 lode claims and relocations have been recorded mainly in the southeast corner of the study area (fig. 1). Complete mine production records are not available; however Clark (1977, p. 28) reported less than $300,000 of gold and silver were produced, mainly from the Exchequer, IXL, and Pennsylvania Mines. Other mines in the area probably yielded are before 1900, but early records are not available.

Jan 1, 1981

By R. Haecker, S. Bajic, R. Thorpe, A. Palko, M. Kalstrom

"Historically, mineral processors have used inferential data like plant instrumentation, assays, and grind sizes to monitor the performance of their plants. The ability to monitor the minerals themselves on a daily basis has eluded all but the very largest and richest of operations. The advent of a new generation of compact, robust, and user-friendly SEM-based automated mineralogy systems looks set to accomplish this, aiming to bring daily mineral monitoring of plant performance within the reach of all mills from mid-size upwards. This paper describes the use of this machine at Greens Creek Mine, a 2.5 ktpd Ag-Au-Pb-Zn operation with a complex flotation flowsheet. During the trial, the machine provided turnaround from sample collection to reporting averaging 24-36 h for key daily samples. All equipment was located within the compact mill, and proved highly reliable despite the challenging environment. Turnaround time was fast enough for metallurgists to understand, and, where possible, respond to ore and process changes while they were still happening. The plethora of data generated was filtered to a simple report whereby mill management could quickly absorb key daily mineral-based performance indicators. This paper will describe how the data was used to understand the key drivers behind metallurgical efficiency at Greens Creek, and how metallurgists began using the information to enhance daily mill performance."

Jan 1, 2014

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"The steps from experimental curiosity through to commercial product can be slow and tortuous in spite of the quality of the technological advances offered by the new development. Data generation and interpretation need to be done in lab tests as well as full-scale evaluations and, in each, the advantages of the new reagent must be clearly identifiable and measurable.The Dow Chemical Company has patented a novel new collector for the flotation of zinc. Fl (2-hexylthioethylamine hydrochloride) has several unique structural features that suggest atypical mechanisms for zinc collection. Laboratory data have demonstrated significant flexibility with respect to grade and recovery balance at dosages lower than those typically used for xanthates.In mill trials, the same phenomanon is evident - the choice between high grade and high recovery allows one to select the desired quality of zinc concentrate. One trial in particular was run over a three month timeframe and Fl gave improvements in recovery of 2.5% and a reduction in lead levels with less than 0.5% loss in grade. The dosages of other reagents in the flotation circuit were also reduced.Data demonstrating improved recovery and grade in lab trials will be discussed. Extensive data from the mill trial will illustrate how Fl works in both rougher and cleaner circuits."

Jan 1, 1990

By James L. Oleson, Hunter R. Propsom, Kevan J. R. Ford, Robert D. Henderson, Bob Musgrove

"Kinross’ Fort Knox Gold mine, near Fairbanks, Alaska has successfully implemented two major metallurgical continuous improvement projects resulting in growth of gold production and an extension of mine life. In 2009, Fort Knox produced 263,153 oz of gold at a cash operating cost of $543/oz. In 2010, approximately 63% of the gold will be produced from the CIP circuit, 15% of the gold from the gravity circuit and 22% of the gold from the heap leach.In 2009, a 44,000 ton per day run-of-mine valley fill heap leach facility was constructed and commissioned as a cost effective treatment option for low grade ores to supplement the higher grade mill. The heap leach facility will produce approximately 100,000 ounces of gold per year under severe winter conditions. Heap leach gold recovery, based on test work shows 30% after a 55-day leach cycle, with long term ultimate gold recovery targeted at 65%. The paper presents the heap leach design concepts and production data.Additionally in 2009, installation of a Knelson gravity concentrator unit (XD70) was completed. This together with an Acacia intense leach reactor (AILR) has increased overall mill gold recovery from 79.3% to 80.7%. A manual shaking table gold recovery operation has been replaced by batch intensive cyanidation of the high grade Knelson concentrates. Increased removal of coarse gold and difficult-to-leach gold species from the grinding circuit, via the gravity circuit, has improved gold leach recovery in the conventional whole-ore tank leach CIP circuit. The paper presents plant operating data, showing the improvements over the old flowsheet.Focus on the metallurgical properties of the high grade and low grade end components of the Fort Knox ore has resulted in significant improvement to gold recovery."

Jan 1, 2011

By G. P. Houston

This is the final, report submitted for the Contract No. H0220002 with the U. S. Bureau of Mines for the design and development of a Permissible Automatic Data Acquisition System (PADAS) to measure and record roof stresses in underground mines Basically the PADAS is a portable, battery powered, 24-channel data acquisition system designed for safe unattended operation of up to 30 days duration in explosive environments. The unit will accommodate twenty-four pressure transducers or eight borehole deformation gages (or any combination) at distances up to 300 feet from the PADAS to measure pressures up to 10, 000 psig. All 24 channels as a selected group are scanned sequentially at one of several selectable rates.

Jan 1, 1973

By David Norval

Water solidification of mattes, metals, alloys and certain slags with high metal entrainment has customarily not been practiced due to the belief that such processes are too dangerous and unproven in the Pyrometallurgical Industry. Slag granulation on the other hand is extensively applied, although in some cases crudely, with disastrous effects, as a result of not recognising the high heat capacities prevalent in slags. This paper will examine the most common air solidification processes and compare such processes with water solidification, mainly slag and matte granulation processes and design criteria for safe and reliable operation. Finally, purpose designed granulation and solidification processes will be discussed taking into account specific applications and the individual signatures of alloys and slags, emphasising that no slag, matte or alloy responds in similar fashion to a granulation practice.

Jan 1, 2006

The flolation behaviour of some Australian uranium ores was investigated. Although uraninite and pitchblend float readily with fatty acids, selective concentration to produce an economically discardable tailing has not yet been achieved. This is attributed to the presence in the ores of a quantity of uranium mineral in finely dispersed form which is very difficult to liberate. For some of the ores, at least, the proportion of this material decreases with increase in head assay.Flotation may be a useful concentrating method for some Australian ores if uranium oxide is to be sold in a free competitive market.

Jan 1, 1967

By G. L. Oldright

This paper is the fourth of a series of preliminary papers on smelting in the lead blast furnace.4 The objects of this investigation are to determine the conditions obtaining within the blast furnace by direct experimentation and to correlate these conditions with operating factors, furnace behavior, and metallurgical losses. ACKNOWLEDGMENTS The authors wish to express their appreciation to the management of the International Smelting Co. at Tooele, Utah, for their whole-hearted cooperation in this investigation.

Jan 1, 1929

By Sidney Katell

Philippine laterite and serpentine ores can be utilized in an electric furnace operation to produce both a steel ingot and a ferronickel product. Figure 1 is a schematic interpretation of a plant in which laterite and serpentine ores are processed separately to obtain both ferronickel and steel as products. A relationship of estimated capital requirements and probable returns has been established in this study for a plant of this type. No attempt has been made to evaluate the risks involved in commercial operations. At such time that the project might be constructed and placed in operation, changes in the costs of material, labor, and power may materially affect the profitability aspects of this study. One of the uncertainties involved in the economic evaluation is the cost of mining, handling, and shipping the ores. It is on this basis that the cost of ore delivered at the plant is assumed to be variable at $3, $5, and $7 per net ton (dry basis). For all other costs a plant site at Iligan City, Philip-pine Islands, has been assumed in preparing the economic characteristics for a plant that will process 2,000 tons4/ of ore per day. Results of the study, for the 2,000-ton plant, with all monetary values expressed in terms of United States currency (Philippine peso valued at $0.50), are summarized as follows:

Jan 1, 1962