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C. N. FEnner, New York City (communication to the Secretary) : A possible explanation of some of the' phenomena of amalgamation cited by Mr. Bayliss and others has occurred to me. We know that if, to a quantity of mercury, gold and silver are added until a putty-like paste is formed, and if this mass is spread on a flat surface and pressure is applied, a more fluid portion of the mercury will be squeezed out from the rest, carrying gold and silver with it. The proportion of gold to silver will depend, I think, upon various causes and conditions—the relative chemical affinity which gold and silver have for mercury; the amount of pressure used; the presence of other metals:

Jan 1, 1898

W. S. GRESLEY, Erie, Pa. (communication to the Secretary): A six-entry method of opening coal-mines is, or was a short time ago, practiced in the Connellsville coal-region; but Dr. Chance's method has a novel aspect; for while in the Connellsville region the main pillars are formed outside of two pairs

Jan 1, 1901

Lower the respirable dust expo-sure of longwall mine workers by reducing the amount of air-borne respirable dust generated during coal extraction. Approach Increase the moisture content of the coal seam through water infusion before the coal is mined. How Water Infusion Works Increasing the moisture content in coal tends to prevent respirable dust from becoming air-borne during mining and transport. The moisture content of the coal seam can be increased by infusing water into the seam. Water under pressure is forced into the cracks (cleats) of the coal seam through sealed bore-holes. The effectiveness of water infusion is a function of the amount of water the coal seam accepts (its infusibility), which depends on the cleat density (cleat spacing) and cleat size (crack diameter). Thus the effect of water infusion on dust control depends mainly on coal seam characteristics. Water infusion techniques are generally used to restrict the flow of methane gas to the working face; however, the technique provides an alternative dust control method in mines with severe dust problems which limit production.

Jan 1, 1987

S. A. Tomich (Consulting Geologist, Perth) : I would like to commend Mr. Haycraft on his presentation on the economic geology of the North End of Kalgoorlie. This is an intriguing area which is in the Kalgoorlie field but not of it, inasmuch as it is separated spatially from the main Golden Mile by the Golden Pike Fault. Mr. Haycraft has stressed the differences-the mineralogical and structural differences of economic significance between the two areas.I would like to ask whether he is satisfied that the lithological sequence in the North End is the duplicate of that in the main Golden Mile area irrespective of the postulated effects of erosion, and more specifically whether there is any chance that the quartz-dolerite-greenstone of the North End may be in any way dissimilar from the quartz-dolerite-greenstoneof the Golden Mile which is tellurude bearing.J. A. Haycraft: In relating the quartz-dolerite in the Hannan's North-Mount Charlotte area back to the Golden Mile, we find some quite close similarities. Although the rocks are similar they are not necessarily one and the same.At Mount Charlotte we have three varieties of dolerite- a coarse-grained gabbroic dolerite on the eastern side of the orebody, the host rock medium grained and on the western side, a fine grained dolerite. Further west we have an amphibolitic variety of quartz dolerite.Recent drilling south of the Golden Pike fault on the Enterprise No. 20 level had indicated a remarkably similar sequence of rocks. We drilled west through a wide section of medium grained rocks into a fine grained rock and then into amphibolitic quartz dolerite before intersecting the Golden Pike fault. Williamstown dolerite was located west...

Jan 1, 1965

By Amy McBrayer, Vladislav Kecojevic, Juan David Valencia Quiceno, Dragan Bogunovic

The mining industry’s commitment to innovation reflects a history of adopting technological advancements to enhance workplace safety, environmental sustainability and vocational training. The objective of this research was to develop an augmented- reality (AR) system for heavy-equipment operators (HEOs) in surface mining. The developed system has the potential to enhance mine safety, training and data-driven decision- making, which presents a significant step toward a more sustainable, effective and technologically driven mining training, contributing to the industry’s evolution and growth. The AR training system leverages Microsoft’s Power Platform and HoloLens 2 capacities to provide operators with detailed and immersive training guides for three mining equipment, including bulldozers, motor graders and haul trucks. AR guides combine speech controls, 3D objects, informative images and explicative videos in the real working conditions to enhance the operator’s learning process. The system has the potential to modify the training structure based on user performance and provides an efficient approach to data collection during training. This project was developed and applied through a case study in a surface mine in the Southern United States.

Feb 1, 2025

By James J. Olson

The Bureau of Mines recorded and analyzed overpressure levels for three production blasts at the White Pine copper mine, Upper Michigan, to obtain representative data from single-heading blasts in a long, straight haulageway and to estimate the damage potential inherent in production blasts fired in close proximity to underground structures. Commercial pressure gages with a flat response to 1 kHz were used with an FM tape recorder to record the overpressures from one dynamite and two AN-FO (ammonium nitrate-fuel oil), 500-msec production blasts having zero-delay charge weights of about 75 lb (34 kg). The recorded waveforms from the underground blasts (1) were more complex than the typical free-air wave, (2) were of longer duration, and (3) had numerous secondary arrivals due to reflections from the ribs and roof. The waveforms showed that the zero-delay charges produced the only high overpressures. First pulse peak overpressures from the blasts ranged from 0.10 lb/in2 (6.9 X 102 N/m2) at a distance of 471.1 ft (144 m) to a maximum of 1.76 lb/in2 (121.3 X 102 N/m2) at 191,7 ft (58.4m) from the blasts. An analysis of variance of the first pulse overpressures from the three White Pine blasts showed that no statistically significant difference existed among the overpressure levels from the dynamite and AN-FO blasts and that a single equation P = 4.9 x 103 (D /W1 / 3) 2 .15, where P = overpressure in pounds/inch2, D = d-stance from the blast in feet, and W = zero-delay charge weight in pounds, could be used to describe the falloff of overpressure with distance.

Jan 1, 1971

By M. S. Seehra, R. S. Pandurangi

"A comparative study of the intensities of the IR modes in the pjlotoacoustic and. FrIR spectroscopy of amorphous and crystalline SiO2 particles is presented. It is observed that in photoacoustic spectroscopy of amorphous SiO2, IR modes of surface species are enhanced by over an order of magnitude compared to the bulk IR modes of SiO2. This effect, though not yet understood, may find applications in surface science.Since the publication of the Rosencwaig-Gersho theory of the photoacoustic effect in solids in 1976 [1], a great deal of attention has been paid to the development .of photoacoustic spectroscopy (PAS) into an analytical technique for condensed matter studies, especially when combined with the modern Fourier transform infrared (FTIR) spectrometer [2-8]. PAS has now been applied to a variety of experimental situations [2, 3] and it is particularly suitable for opaque powders and for cases where ~ample preparation (e.g. mixing with KBr as is usually done in FTIR spectroscopy) is not desirable. Another area of interest is the depth profiling feature of PAS, which is studied by varying the modulation frequency of the incident radiation [2-8]. The one-dimensional Rosencwaig-Gersho theory for non-porous samples has been extended to other cases [9-12]. Recently it has become known [11, 12] that for porous samples with porosity the IR modes are enhanced by a factor proportional toe. This enhancement is due to the pressure wave set up in the interstitial gas in the porous sample and this enhancement has been reported by a number of groups [12-14].In this Letter we report the observation of anomalously large enhancement of the PAS signal for certain surface IR modes on the surface of amorphous silica particles. This observation differs from the previous reports in that certain surface modes are enhanced by over an order of magnitude compared to the bulk IR modes. Although the reasons for this enhancement of the surface IR modes in PAS are not understood at present, this observation may open up new approaches to the study of surfaces. Results of these initial observations are given in this Letter. ·Experimental studies reported here were carried out on an FTIR spectrometer (Mattson Instruments, Model Cygnus 100) equipped with an MCT detector. The same instrument was used for PAS studies in conjunction with an MTEC (Model 100) PA cell. The sample cell and the spectrometer are continuously flushed with dry, CO2 free air obtained by the use of Balston Instruments Air Dryer Filter System (Model 75-60). Usually data were collected for 32 scans at 4 cm-I resolution, although both scan and resolution can be varied. For FTIR studies, samples were mixed with IR-grade KBr and pelletised. For PAS, no sample preparation is necessary and data are ratioed against dry carbon black [4, 5]."

Jan 1, 1989

By Dong Hoon Han

The simultaneous sulfation by sulhr dioxide and oxygen of CaO and MgO in calcined CMA (calcium magnesium acetate) were investigated. he experiments were carried out in the temperature range from 700 to 830 "C and at the SO2 concentrations of 0.3 to 1 mol %. The oxygen concentration was kept at 5 %. Each sample was calcined completely before the temperature was lowered to the sulfation temperature. According to the ranges of partial pressure of sulhr dioxide and temperature, there exist three regions for the sulfation reaction: region I in which neither oxide is sulfated, region I1 in which only CaO is sulfated, and region 111 in which both oxides are sulfated. It was shown that the MgO in calcined CMA is sulfated at a rate comparable to that of CaO by forming a mixed sulfate phase. Thus, unlike MgO contained in other desulhrization materials, the MgO content in calcined CMA can be fully utilized for flue gas desulhrization.

Jan 1, 1999

By Sibley C. Burnett

Early attempts to apply superconductivity to the beneficiation of kaolin required very large refrigerators to remove the heat generated during rapid charging and discharging of the magnet. In the early 1990's, Advanced Cryo Magnetics, Inc. developed and patented methods to reduce this pulsed heating by a factor of fifteen. Small, helium refrigerators and cryo-coolers are now used. Along with savings in electric power, superconductivity allows operation at higher magnetic fields and greatly improves separation process efficiency. New designs offer enormous reductions in weight, size and capital cost as compared to older copper magnets. Application of this technology to minerals other than kaolin is emerging.

Jan 1, 1999

By Tsisana Gagnidze

A processing of technogenous wastes, which involve a gold-containing sulphide minerals, is a potential source to supplement the gold reserves. Hence, searching of ecologically safe and economically reasonable methods for processing of gold-containing technogenous wastes is a topical problem. To increase a parameters of gold extraction and to simplify a technology of the processing of above-mentioned wastes of sulphide minerals, an investigations have been carried out in the direction of the use of the method of electrochemical leaching without any preliminary processing of the mineral. It was established experimentally that an introduction of nitrogen containing organic additive into chloride solution favours to reduce a Red/Ox potential of the solution from 0,8÷1,2 V to 0,35÷0,5V, which permits to conduct the process of direct electrochemical leaching at ?soft? oxidation regimes at temperatures 20-300C C without an environmental contamination by molecular chlorine and with a high degree of a gold extraction up to 80-90%.

Jan 1, 2008

Presentation Topics ? Low and Intermediate Level Waste ? Project Location and Site ? Geological Setting ? Key Features ? Project Overview ? Licensing and EIS ? Next Steps DGR Waste Package Inventory Approximately 50,000 packages over 35 years: ? ~40,000 packages or 80% of inventory are LLW Bins ? ~7,000 ILW Shields (concrete boxes) ? ~2,000 resin liner packages

Oct 1, 2010

By Eric E. Cather

A mineral investigation by the U.S. Bureau of Mines revealed no mines or prospects and no past or present mining claims in the Agua Tibia Wilderness Study Area (WSA). The area is underlain mainly by weakly foliated gabbro similar to rock that has hosted gem- and lithium-bearing pegmatites in the Pala district about 6 mi to the south. However, no gem- or lithium-bearing pegmatites have been discovered in the WSA. Nearby quarries in the gabbro have yielded rock for facing and dimension stone. No sand, gravel, or energy (oil, gas, coal, or geothermal) resources were identified.

Jan 1, 1984

By J. C. Armbrust

The Morenci Open Pit Mine, located in south-eastern Arizona, is owned and operated by Phelps Dodge Morenci, Inc. The Mine has been predominantly a rail mine since its origin in 1937. However, beginning in early 1986, a program was initiated to phase out the rail mining operation and replace it with a more flexible and productive truck haulage scheme. This transformation from rail to truck haulage will be accomplished when the current in-pit crushing and conveying project is completed in late 1988.

Jan 1, 1988

By E. Sabah

A series of adsorption tests are carried out to understand the ability of cationic surfactants and metal ions to adsorb onto sepiolite. Adsorption tests conducted as a function of heat treatment reveal that sepiolite is rather conducive to the uptake of both organic and inorganic ions. An ion exchange mechanism between surfactant or metal cation and magnesium ion followed by chain-chain association is proposed to explain the incorporation of cationic surfactants into the structure of sepiolite.

Jan 1, 1998

By S. D. Tolgyesi

Kidd Creek Background ? Located in Northern Ontario, Canada ? Underground base metal mine ? Operating since 1966 ? Total of 125Mt mined to date (2.43% Cu, 6.60% Zn) ? Current plan at 2.4Mt/Y (6575t/D) Current Practices ? Evaluating stope margins to ensure that value is added ? Scheduling sulphide and Cu stringer ore to limit oxidation in passes ? Scheduling to maintain uniform grades to concentrator ? (SOPs highlight problem stopes on mine plans, and limit blast sizes in those stopes which may contain sulphides prone to oxidation) ? Scheduling high-Pb stopes to avoid spikes to concentrator ? Providing weekly, monthly and long-term forecasts ? Reconciling mine and mill production ? Underground grade and dilution estimates by mine supervision ? Terminate mucking when grade becomes sub-economic ? Laser cavity surveys to provide feedback and improve Designs Cut-off Grades ? Ore value is obtained from copper, zinc and silver ? Ore outlines at 2% copper equivalent used to guide stope planning; sulphide outlines obtained from contacts while copper stringer outlines drawn from block model (kriged) ? Datamine block model and CADD software used to evaluate alternative stope shapes ? Stopes classified as waste, incremental, or full-cost based on margin calculations for each stope ? Incremental ore may be mined if it does not displace fullcost Ore Conclusions ? Grade control remains an important function for optimizing the ore extraction at Kidd ? The scope of the function has changed to a scheduling focus ? A change in grade control practices over time has not led to significant changes in concentrator feed ? The lead and iron sulphide content of the ore display upwards trends and may require more attention in the future ? The key function of field observations has shifted to flagging exceptions and terminate mucking at grade cut-off

May 1, 2003

By George Kellock

In presenting this paper for discussion at the Western Annual Meeting to be held in Edmonton, it is with the idea of creating a full and general discussion by the mining men in the Province as to the best way to eliminate, or at least hold down to a minimum, the dangerous coal-dust which is made in mining pitching seams in our Alberta mines by the chute method. Also, an alternative method is outlined, whereby the percentage of lump-coal mined can be increased, and the mining costs reduced-although the paper does not go into any detailed consideration of costs. The general trend of mining practice and lay-outs is at present towards mechanization, and the results being accomplished by the substitution of machines for manual labour are fully justifying the changes. In the technical mining journals, there are published from time to time papers dealing with a variety of methods of mining, which are descriptions of actual operations, and a great deal of interesting and valuable data is given as to the comparative values of the different methods, insofar as the percentage of grades of coal produced, the cost of production, etc., are concerned; but the mechanical methods described in these papers are nearly always suitable only for flat seams, or seams with a very low inclination.

Jan 1, 1929

By A. V. Castelli

The provinces of Guangxi, Guizhou, Hubei (and most recently Fujian) were the prime exporters of barite during this period. Guangdong and Shandong were exporters too but not major participants. These are all primarily agricultural areas so there existed a sufficient labor force willing to work in the mines to supplement their income from farming. During the early years, barite export pushed the existing transportation systems in these provinces to operational capacity. The mines from which this barite is extracted are located about 250 to 1,400 kilometers from the sea ports. Transportation of the ore from the mines to the ports follows a net-work that includes trucking to various rail-heads where it is then shipped via freight trains to ports for loading into seagoing vessels. in some instances, the barite travels by truck or train to the Yangtze River where it is then barged to an ocean port.

Jan 1, 1990

By I Lipton

The existence of metalliferous mineral deposits on the deep-sea floor has been known since manganese nodules were discovered in the Arctic Kara Sea in 1868. Modern exploration to define commercially viable base and precious metal deposits began in the 1970s and gained further momentum in the last decade. High grade deposits have been delineated but investors remain cautious, many considering deep sea mining projects to be riskier than terrestrial projects. This paper compares opportunities and risks presented by terrestrial mining projects with those presented by deep sea mineral deposits (Table 1). The Solwara 1 volcanic-hosted massive Cu-Au-Ag sulphide deposit, the Atlantis II Deeps sedimentary base metal sulphide deposit, and the Mn-Ni-Cu-Co nodule deposits of the north-eastern Pacific Ocean are used as examples. These are advanced deep-sea projects with published Mineral Resource estimates, on the cusp of development. Off-shore diamond mines in Namibia are also considered. These examples provide a basis for comparing exploration and geological uncertainty, the technical risks of proposed mining systems, and the potential environmental and social impacts. CITATION: Lipton, I, 2018. A comparison of opportunity and risk in deep-sea and terrestrial mining projects, in Proceedings Complex Orebodies Conference 2018, pp 102–105 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By R. S. Scheetz

The search for a more effective means of coping with methane liberation has resulted in the expanded use of seam degasification. Its advantages are measured not only in reducing the hazards due to methane, but also in producing a marketable commodity: .the gas, itself. However, the success of a methane drainage system is the culmination of many complex factors, the most important being the coal seam permeability. The two most popular drainage techniques used mining today are the vertically simulated borehole method and the in-seam horizontal borehole method. The objective of this paper is to determine the permeability range in which the selection of the degasification technique is based primarily on equipment and economic analysis. A discussion of the equipment involved will be incorporated into examples evaluated by the Penn State coal methane simulation model.

Jan 1, 1989

By Wilbert T. Malenka

In its search for a highly productive mining system for anthracite beds pitching from 100 to 200, where conventional mobile equipment cannot be used) the Bureau initiated a longwall project by introducing a shearer drum cutter loader of European origin. Because of the undulating nature of the roof and floor and changing bed thicknesses, the machine proved inflexible and extra work was required in lifting bottom coal and blasting top coal.

Jan 1, 1966