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By Lincoln A. Stewart

"INTRODUCTION The First Supplemental National Defense Appropriation Act, approved August, 25,, 1941, authorized the Bureau of Mines to investigate sources of raw, material for western production and appropriated funds for that purpose. Numerous iron deposits and prospects in the Western States were investigated. Among those selected for more detailed investigation were tile Apache and Chodiski deposits in Arizona.The United States Geological Survey had examined these deposits in 1929 3/ and estimated that ""the quantity of minable ore reasonably to be expected in this locality will reach 10,000,000 long tons, but it will require prospecting by core drill to demonstrate this quantity with certainty"". C. H. Johnson, a mining engineer of the Bureau of Mines, made a preliminary examination in October 1941 and proposed exploration of the Apache deposit Canyon Creek.A trench sampling project was set up, and work at the Apache deposit commenced in November 1941. Mapping, trenching, and sampling of outcrops was completed in March 1942. Trenches were laid out at approximately 200-foot intervals for about 9,200 feet along the iron outcrop east of Canyon Creek, and channel samples were taken across the iron formation. The outcrop also was explored by trenching and sampling along a 1,900-foot outcrop on the west side of Canyon Creek.The first diamond-drilling campaign at Apache was initiated in May 1942 and continued to January 1943, when work was suspended owing to depletion of funds. Six holes spaced at approximately 500-foot intervals and, 500 feet back from the outcrop on the east side of Canyon Creek were drilled through the iron formation during this period.While this drilling was in progress, the Chediski deposit was mapped, trenched, and sampled. The trenches were spaced at intervals of approximately 800 feet along 10,000 feet of the iron-ore outcrop."

Jul 1, 1947

By Edwards A. B

In their description of the post-mine leaching of galena and marmatite at Broken Hill, Messrs. Garretty and Blanchard1 find themselves unable to account satisfactorily for the fact that the more usual order of solubility of these two minerals is here reversed, and that the galena is leached more rapidly than the marmatite. An explanation of this somewhat unusual phenomena is perhaps provided by the recent work of Garrels.2 Garrels showed that the presence of Cl' ions in Pb-Zn solutions, in concentrations in excess of 0·1 N, rendered the zinc less soluble than the lead. It seems possible that Cl' ions may be present in the underground waters of the North Broken Hill Mine in sufficient concentration to cause such reversal in the relative solubility of the lead and zinc sulphides.Thus the analysis of "water believed to be free from contamination by mine drainage" given by Messrs. Garretty and Blanchard (p. 158 of their paper) is as follows:Total solids in solution 878 grains per gallon...164 grams of Cl per gallon is equivalent to 2· 3394 grams of Cl' per litre, which is equivalent to 0066 N.This concentration is approaching a value sufficient to cause a reversal of the relative solubility of zinc and lead salts; and it seems probable that there will be parts of the ore-body where locally the Cl' concentration will greatly exceed this figure. At such points the lead salts would be more soluble than the zinc salts, so that the galena would be leached more rapidly than the marmatite. With the dilution of such Cl'-rich waters with water containing less Cl', the Cl' concentration would fall below 0·1 N, and the lead would be reprecipitated, while the zinc would stay in solution, as, for example, in the water analysis quoted. The other point on which the authors speculate is the reason why the Northern Ore-body in the mine has undergone greater leaching than the...

Jan 1, 1942

By F. D. Wang

This paper presents an innovative mining method with the application of the water jet. The basic principle of this mining method is to mine a thin panel slice with a water jet system and to allow the roof to deflect elastically and subsequently to be supported by the coal floor without artificial roof support. Through the sequential mining of layers from top to bottom, the entire seam is extracted and the roof rests upon the mine floor. The advantages of this method are that the safety of underground operation can be greatly increased and the surface overburden disturbance will be markedly reduced. . An economic evaluation of such a system is presented for the total cost estimated per ton of coal mined at the face. This evaluation is then compared to that of a continuous mining section utilizing a room and pillar mining method.

Jan 1, 1991

By F. W. Richard

This paper describing the mining practices at the Ground Hog Unit of the Asarco Mining Co., a subsidiary of the American Smelting and Refining Co., is one of a series being prepared by the United States Bureau of Mines on mining methods, practices, and costs in the various mining districts of the United Stated. The Ground Hog mine is at Vanadium in the Central mining district, Grant County, N. Mex., about 1.0 miles east of Silver City and 2 ½ miles southwest of Santa Rita. A branch line of the Atchison, Topeka & Santa Fe Railway connects Vanadium with Deming, about 45 miles southeast.

Jan 1, 1930

By A. K. Sheik, W. G. Pariseau

A small underground mine in northern Idaho was used as an experimental facility for studying the role of water in the analysis of mine opening stability. Laboratory test data, borehole measurements and geological mapping assisted in constructing a coupled finite element model of the rock mass. The model was used to make quantitative estimates of: 1) rock stress, strain and displacement changes, and 2) water pressure and flow velocity changes that occurred during historical mining. Stope cuts and wet fills were included in the analysis. Stability of crown pillars between stopes was of particular interest. The relatively low effective stress and high rock mass strength showed that water pressure changes were of no great consequence in agreement with experience. The computational tools used in the analysis may be applied to other wet mines with appropriate changes to site-specific input data.

Jan 1, 1999

By L. D. Hall, S. J. Rothman

The diffusion of lead and of trace amounts of bismuth in liquid lead have been investigated by the capillary method, using ROD and ROE as tracers. The results are compared with existing theories of diffusion in liquids, the agreement with theory being fair. The heat of activation for self-diffusion in lead is found experimentally to be close to the corresponding activation energy obtained from viscosity data. The pioneer data of Groh and von Hevesi for the self-diffusion of liquid lead, using ThB as a tracer, fit in with the present results. OMPARED with the volume of effort expended on solid state diffusion, there has been little attention paid to diffusion in liquid metals. A review of experimental work in this field, covering most of the studies up to 1951, was given by Jost.' More recent papers include those by Hoffman2 on self-diffusion in mercury, Morgan and Kitchener" and Stark, Shchilishchev, and Kazachkev4 on the diffusion of various elements in liquid iron, and Grace and Derge on the diffusion of bismuth in bismuth-lead alloys. The need for more experimental data to aid in the evaluation of existing theories prompted the

Jan 1, 1957

By H. Do

In flotation, hydrophobic particles are selectively collected by air bubbles, and the bubble-particle aggregates enter the froth phase. However, less hydrophobic particles drop off from the froth phase, while more hydrophobic particles are recovered. Thus, the froth phase provides an important cleaning mechanism. In the present communication, the froth-phase recovery process has been modeled by considering particle retention times and the carrying capacities of bubbles. The model predictions are compared with the experimental data reported by Seaman et al. (2006). The results show that the froth-phase recovery varies with particle size, particle hydrophobicity, and bubble coarsening.

Jan 1, 2008

"Many underground mines are achieving extended life and optimizing existing facilities by mining at greater depths. The challenges to do this require a sound engineering approach to mine design and mine services, as well as ingenuity in safety design. The social consequence is full utilization of existing infrastructure.Accessing ores at depths of 2000 m to 3000 m requires exceptional hoisting design. May’s theme issue includes a paper that examines a case study of one such hoisting plant, with emphasis on the hoist rope selection at Agnico-Eagle’s Penna shaft. The paper also describes the process whereby consultation with provincial safety authorities resulted in a revised safety factor suited to the hoist. Another paper examines the challenges of ventilating mechanized mines to 3000 m, including air cooling and dilution of diesel exhaust emissions. Vent system designs are discussed, using sound engineering design, and proven technology that minimizes emissions to achieve cost efficiencies. The paper suggests design based on process and ventilation simulators to obtain realistic economic data at the design stage. Increased ground pressures present unique challenges for production and safety. While this is not confined to deep mining, one paper examines rock pressures and seismic events at the Brunswick mine, for which experience may be applied at depth. It describes seismic monitoring as a predictive tool in a real mine situation, and how it is used to improve overall recoveries and maintain worker safety."

Jan 1, 2004

Vatukoula, the Fijian equivalent of gold rock, is the name of the community embracing the gold mines owned and operated by Emperor Gold Mining Company Ltd., Loloma (Fiji) Gold Mines, N.L., and' Dolphin Mines Ltd. It is situated in the Tavua Goldfields approximately five miles from the northern coast of Viti Levu, the largest island of the Colony of Fiji.The climate is sub-tropical, there being a definite wet and dry season. The wet season is somewhat variable in length but usually extends from December to March, during which time most of the rainfall for the year is recorded.Although the average annual rainfall is 71 in., more than twice this amount has been recorded. Precipitation at the rate of 5 in. per hour is not uncommon and 15 in. of rain has been registered in 24 hours. The mining methods adopted, therefore, had to suit these wet conditions.The occurrence of gold in the Tavua area has been known since 1872, but it was not until 1932 that discoveries were made which led to the formation of the present operating companies. In 1934 the Emperor Gold Mining Company Ltd. commenced operations, followed in 1935 by the Loloma (Fiji) Gold Mines, N.L., and later by the Fiji Mines Development Ltd., now known as the Dolphin Mines Ltd. Up to the end of 1951 these three mines had produced 2,501,688 tons of ore from which 1,277,881 oz. of fine gold and 347,429oz. of silver were obtained, realizing in Fijian currency £13,025,153.The three mines are situated close togeth.er on contiguous mining leases, and, although under common management, are operated as separate en,tities. Since 1944 all the...

Jan 1, 1953

By Alexander Malahoff

With its new continental shelf beyond the exclusive economic zone, New Zealand is a country with just 4% of its territory above water. The other 96% is submerged. New Zealand's marine territory covers an area about three-quarters the size of Australia. This territory includes large portions of the Gondwana continent from which NZ separated more than 80 million years ago. This underwater land mass extends from the shores of New Zealand to a water depth of more than 5,000 m, is largely unexplored and is almost certainly the site of many large, untapped oil, gas and mineral deposits. Underwater oil and gas drilling is now a universal activity. Underwater mining is in its infancy and will become a major activity in the future, contributing greatly to the New Zealand economy. New hydrocarbon deposits will undoubtedly be discovered under the ocean floor in regions such as the Great South Basin located off Canterbury and Otago. Mineral deposits are also undoubtedly located within the oceanic crust of this underwater NZ continent. These are as yet unknown and unexplored. The oceanic crust north of the North Island is currently being extended through the subduction of the Pacific plate into the Tonga Kermadec trench and through the growth of a line of submarine volcanoes extending north to Tonga. Active submarine volcanism has led to the growth of ocean floor mineral deposits consisting of polymetallic sulphides with iron, copper, zinc and lesser gold, silver and other metals.

Jan 1, 2011

By Gerhard Derge

Metallurgists have used borax as a fluxing agent traditionally, but until recently elemental boron has played an insignificant role as an alloying element. Neither the metal nor its compounds have been regarded as important metallurgical materials and there is a surprising lack of knowledge concerning their metallurgical behavior. The new applications to steel-making of both boron and borates, which arose in part from wartime incentives and restrictions, have been seriously handicapped by this lack of data. For example, rasorite, a naturally occurring sodium borate, has been shown to be an effective substitute for aluminum as a ladle deoxi-dizer in rimming steels.' Likewise, the effectiveness of boron as an alloying agent has been demonstrated,2,3 giving deep hardening when used in restricted amounts. The exploitation of both of these uses has been retarded by the difficulty of attaining suitable metallurgical control. Recognizing that the most important information required was a knowledge of the equilibrium between boron and oxygen dissolved in liquid iron. Gurry4 calculated this relation from the best thermal data available. However, estimates of the entropy of melting of boron, the activity coefficient of boron in liquid iron and the activity coefficient of B2O3 in slag were involved, and experimental work on this problem was obviously desirable. The experiments to be described were planned to establish the boron-oxygen relations in liquid iron and to demonstrate at the same time the ferroborate slag compositions in equilibrium with various amounts of oxygen in liquid iron. Accordingly, slags containing varying proportions of iron and boron oxides were held in contact with molten iron, and samples of both slag and metal were analyzed. The limitations upon the accuracy of the data will be considered, but in a practical sense the oxygen levels that can be attained in iron by iron borate slags, and the amounts of boron in iron at these oxygen levels were established. Experimental Procedure No entirely suitable refractory was found for the mixtures of iron oxide and boron oxide used as slags. Crucibles of silica, magnesia, Ramix, beryllia, and zirconia were all tried unsuccessfully. The must satisfactory method discovered for handling them was the rotating-crucible technique, which creates a parabolic crucible of liquid iron.5,6 Even this was not entirely successful, for at steelmaking temperatures (1600°C.) the slags had such a low surface tension that they crept up to the refractory and slowly dissolved it. These difficulties made it impossible to maintain a constant slag composition for an unlimited period Of time. However, by using the rotating technique, short runs could be made in

Jan 1, 1947

By Theron Wasson

Michigan produced 16,637,000 bbl. in 1937. This makes it a record year in the history of Michigan's oil industry. During the year 953 wells were completed; 779 within the limits of established fields and 174 wildcats; 616 new oil wells, 68 gas wells and 269 dry holes. Table 1 has been arranged in alphabetical order of field names. Production figures for 1936 have been corrected because December figures were estimated. In this year's summary, December production is based on actual reports. The Leaton and Mt. Pleasant fields have been re-defined. Mt. Pleasant production north of the south line of Denver township, Isabella County, has been included with Leaton in accordance with usual practice in Michigan. The locations of fields discovered since the last map was published1 are shown in Fig. 1. Activity during 1937 Buckeye Field.—The Buckeye field of Gladwin County was the center of greatest activity during the year and was responsible for the increase of 4,700,000 bbl. over the state total for 1936. Buckeye produced 6,428,-000 bbl. in 1937. In this field 328 producing wells were completed during the year—over one-half the oil producers drilled in the state. Buckeye was subject to voluntary and cooperative proration from April 1 to the end of the year. Other pools of the state were not prorated. The new production at Buckeye is from porous Dundee limestone of Devonian age, similar to the older fields. Other New Fields.—The Sherman field was second in importance as a source of new production, with a total of 1,532,000 bbl. Salem township, Allegan County, on the southwest side of the Michigan Basin, was developed during the year. Production at Salem is from the Traverse limestone at a depth of 1600 ft., and 52 producing wells have been drilled in this pool. Other active pools were Clayton and Adams townships, Arenac County. The Bentley pool, discovered in October 1937 southeast of

Jan 1, 1938

Martite-goethite high-grade iron ore deposits that show no trace of hydrothermal alteration may extend to more than 200 m below the permanent water table and are typically saprolite with evidence of exposure to the physical, chemical and biogenic processes of soil formation restricted to the low-grade goethitised upper levels. Typically no evidence of the prior presence of chert bands is discernable within the ore yet it has been assumed that these ore deposits derive from cherty banded iron formation (BIF) through supergene leaching of the chert bands and thus classified as supergene iron ore deposits. The fact that chert bands are absent and that these ore deposits are highly weathered does not prove supergene leaching of the chert bands. Quartz is one of the most resistant minerals to chemical weathering within the saprolite and large scale dissolution of quartz is absent from all other quartz-bearing saprolites, yet this unlikely process is accepted without question as the origin of the most abundant form of high-grade iron ore deposits. It is proposed that martite-goethite high-grade iron ore deposits formed only from BIF in which chert bands were absent prior to weathering. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Collier D

The topaz resource at Torrington in northern N.S.W is currently the subject of a joint research and development programme managed by Pacific Copper Ltd, This programme has culminated in a pilot topaz calcination plant, located at Parramatta, which, through its operation, will establish the commercial viability of developing this mineral as an industrial raw material for both the refractory and fluoride chemical industries.

Jan 1, 1989

The patented "Epytensic" pump of Minnovation Ltd, a multiple piston pump, is used widely on shearer loaders and by partial high pressure watcr jet cutting strategically in relation to cutter picks not only improves cutting rates, but saves power and increases the life of gearboxes and picks, as well as improving dust suppression. The "Face Side Pump", also a piston pump, located on the ranging arm gearhead has advantages over gateroad pumps and shearer body pumps. The "Extraction Drum", hydraulic air mover system, linked with the above innovations and high pressure water, have further advantages in methane and dust removal. Some modifications providing these systems need workshop applications but most are possible underground with minimal changes to shearer profiles and advantages of minimising hosing, along with the other advantages stated.

Jan 1, 1991

By C. J. Hunter

Prior to the commissioning of the Sansu Sulphide Treatment Plant (STP), Ashanti Goldfields' treatment facilities were capable of producing some 700 000 ounces of gold per annum. Ore sources were underground refractory sulphides, surface oxides and old tailings dams. In order to increase the mines production to 1 million ounces per annum and to accommodate the change in ore sources as surface mining moved into fresh sulphides, a part of the strategy adopted was -the construction of a new sulphide treatment plant with a capacity to mill 2.2 million tonnes per annum and produce 400 000 ounces of gold. The STP has been designed, built and commissioned. and has been in operation since February 1994. The Plant boasts the world's largest Bio-oxidation facility which is capable of treating 790 tonnes of sulphide concentrate per day at a grade of 11.4% sulphur and is currently undergoing an expansion to increase its capacity to 1050 tonnes per day. The following sections describe the reasons for selecting the BioX® Process, the plant design, the commissioning experience and the plant performance to date.

Jan 1, 1996

"An innovative concept is proposed whereby the operating power for haul trucks in certain areas of an underground mine are reduced in order to lower ventilation costs. Airflow that must be provided for diesel-powered equipment in most jurisdictions are regulated based on engine peak power capability and engine emissions, both of which can be lowered by artificially reducing the capacity of the engine through the engine control unit. Advances in asset tracking and ventilation on demand enable this methodology and this study demonstrates that it could represent significant value for mine operators. An examination of haul truck duty cycle indicates that de-rating of engine operating power based on the truck’s location in the mine can enable a step change in ventilation rates, often with no material impact on working conditions. Methods for implementation and estimate of cost savings will be defined.INTRODUCTION Ventilation of underground workings remains a significant operating cost burden for modern mine operators. In particular, ventilation rates for underground diesel mining equipment are often defined by local regulatory bodies and are assumed to present minimal opportunity for optimization or savings, at least until battery propulsion systems can be adopted. Commonly, the quantity of air flow required is defined by the peak rated engine output power of diesel equipment. For example, Ontario Regulation 854 SS 183.1 (3) states that “The flow of air must be at least 0.06 cubic metres per second for each kilowatt of power of the diesel-powered equipment operating in the workplace”. Jurisdictions that define air flow using the prescribed CANMET or MSHA ratings use peak engine emissions to calculate air flow required for dilution ventilation. These approaches are similar in that the maximum power capability of a vehicle’s engine is used to define the ventilation rate in all areas where it travels, regardless of what power output is actually used in any of those areas. Examination of the duty cycle of a typical underground haul truck identifies a large variance in the power output of the vehicle depending on its location in the mine and the activities undertaken at these locations. For example, travel on a mining sub-level requires a fraction of the truck’s peak power due to the minimal grade and significantly reduced travel speed. So if we can reliably reduce the peak engine power capacity and engine emissions in areas where peak power is not required, we can logically cut the ventilation rates for those areas."

Jan 1, 2017

By D. Newman

"This paper discusses the author’s work on international law norms of consultation with Indigenous communities and examines unexpected corporate stakeholder impacts on these norms. Customary international law, which governs the area, does not traditionally refer to corporate conduct. This paper surveys several sources on developing international law on consultation obligations; it also discusses the impacts these norms can have on corporate stakeholders in the mining industry. Finally, it asks how interactions of corporate stakeholders in this area can indirectly impact future law and suggests implications for different business models in the mining sector.RÉSUMÉ Le présent article traite du travail de l’auteur sur les normes de consultation avec les communautés autochtones contenues dans le droit international et examine les impacts inattendus des parties prenantes sur ces normes. Le droit coutumier international, qui gouverne ce domaine, ne réfère traditionnellement pas à la conduite des sociétés. L’article analyse plusieurs sources traitant du développement de nouvelles lois internationales sur l’obligation de consulter; il traite aussi des impacts que ces normes peuvent avoir sur les parties prenantes dans l’industrie minière. Finalement, il pose la question à savoir comment les interactions des parties prenantes dans ce domaine peuvent avoir un impact indirect sur les lois futures et il suggère des implications pour divers modèles d’affaires dans le secteur minier."

Jan 1, 2015

By M. Fan, M. Mankosa, G. Luttrell

"Column and other non-conventional flotation approaches continue to provide benefits where conventional flotation processes have exhibited limited success. This is particularly evident with respect to flotation of ultrafine and coarse particles. Advancements in air sparging technology have provided the ability to produce finer bubbles than previously possible. The generation of finer bubbles coupled with the froth washing capabilities of a flotation column has demonstrated improvements in ultrafine particle recovery while simultaneously producing a high-grade float product. On the other side of the spectrum, the use of these sparging technologies while applying flotation fundamentals to a fluidized-bed reactor has increased the maximum floatable particle size up to and in excess of 3 mm. Benefits of higher recoveries and reduced reagent consumption have resulted from the use of these technologies. An additional benefit includes a reduction in plant grinding requirements. As such, this paper describes the application of Cavitation-Tube sparger technology and fluidized-bed flotation (HydroFloat). A review of data from industrial and pilot-scale applications is also provided.INTRODUCTIONConventional (mechanical) froth flotation is considered the workhorse of the minerals processing industry. This low-cost process makes it possible to selectively recover minerals by exploiting the difference in surface characteristics (e.g., wettability) of the valuable component and the waste material. Unfortunately, the upper particle size limit for flotation rarely exceeds 0.600 mm, and is typically maintained at less than 0.300 mm for most industrial applications. For many commercial base metal plants, the particle size range for optimum recovery is typically between 0.01 and 0.1 mm (Lynch et al., 1981). This finding is not novel. In fact, the effect of particle size on flotation recovery was studied as early as 1931 by Gaudin et al. who showed that coarse (+0.250 mm) and extremely fine particles (-0.010 mm) are more difficult to recover than particles of an intermediate size. The loss of recovery is due to inherent limitations associated with the flotation process, including bubble-particle adhesion and collision, detachment, buoyancy, and transport."

Jan 1, 2010