Search Documents

By D. A. Reynolds

[A few studies on the relationship of the fusion temperature of the ash of coke to that of the corresponding coal have been made on commercial high-temperature cokes. R. J. Rose3/ in 1921 compared the' fusion temperatures of the ashes of 10 coals and. the cokes produced from them and concluded tat they were in such close agreement that either figure could be used. More recently, Quarfort4/ found that the ash of coke fused at a somewhat lower temperature than that of the original coals As the ash of a coal and that of the coke produced therefrom have the same origin their chemical composition should be identical, provided that carbonization has not altered the inorganic, or ash-forming, constituents of the coal, and such alteration seems highly improbable. However, it has been shown5/ that coke is liable to contamination by iron during crushing and preparatory to sampling. Pieters6/ found that coke ash was cantaminated in this manner up to 0.4 percent. extraneous iron would lower the ash-fusion temperature because such iron may form ferrous silicate, which is readily fusible,7/ These results provide a basis for the prediction that the ash of coke will fuse at a lower temperature than that of the corresponding coil., especially if the fine grinding of the coke was done by rubbing surfaces of iron, as in a disk pulverizer or bucking plate.]

Jan 1, 1940

At the exploration stage for new mining projects or for medium- and long-term areas of existing mines (typical of South African gold mines), drilling data is on a relatively large grid. This grid is normally larger than the selective mining units (SMUs). Direct estimates for the SMUs and also of much larger block units will then be smoothed due to the information effect and the high error variance. Any capital-intensive project decisions made on the basis of any of the smoothed estimates will tend to misrepresent the economic value of the project or operation, i.e. the average grade of blocks above cut-off will be underestimated and the tonnage overestimated for cut-off grades below the mean grade of the orebody. This paper presents a direct approach technique for deriving recoverable resources, referred to as localized direct conditioning (LDC), designed to correct smoothing effects and also to provide support corrections.

Jan 1, 2014

By C. A. Wilson

The Bureau of Mines started a continuing program to investigate and evaluate analytical techniques to assist governmental agencies to select simple, rapid, reliable methods for crude oil spill identification. Six crude oil samples were analyzed to evaluate gas-liquid chromatography, atomic absorption spectrophotometry, infrared spectoscopy, sulfur and nitrogren determinations, mass spectrometry, nuclear magnetic resonance spectroscopy, and ultraviolet spectrophotometry. Samples were studied from the following selected fields: El Morgan, Egypt; Duri, Indonesia; Minagish, Kuwait; Bachaquero, Venezuela; Gach Saran, Iran; and Prudhoe Bay, Alaska. These samples were chosen to represent high-production fields that are likely to be involved in oceanic transport. Over 50 years of Bureau of Mines analytical research on petroleum served as the basis for evaluation of the experimental results to determine which of the methods are effective techniques to identify crude oil spills. Gas-liquid chromatographic analysis, atomic absorption spectrophotometric analysis, and sulfur-nitrogen determinations are recommended as the most useful of the techniques investigated.

Jan 1, 1975

"INTRODUCTION These inspection standards have been prepared for use as a guide for the Federal inspection of anthracite mines. They are a revision of ""Tentative Inspection Standards for Anthracite Mines,"" published as Bureau of Mines Information Circular 7231 in January 1943 and used as a guide for Federal inspections. Numerous changes in the original standards have been made, due in part to recognition of shortages of some types of safety equipment due to the war, in part to need of additional standards to cover certain mine conditions and practices, and in part to conditions not foreseen when the original standards were prepared.Throughout these standards reference is made to determining the methane content of the mine air by using a permissible flame safety lamp. The Bureau has approved various electrical devices for the detection of methane, but it is recognized that new devices for determining the percentage of combustible gases as well as the percentage of oxygen, might be perfected for general use in mines, and therefore it may be necessary to revise certain standards to include the use of such equipment if and when the device is accepted as being permissible.About one-fourth of these standards are marked with an asterisk (*) as being of particular importance in preventing accidents in many coal mines; however, failure to carry out the suggestions made in such of the other standards as are applicable may also lead to loss of life.With continuing change in mining methods, some of these standards may become inapplicable, and further revision will be advisable. Therefore, question regarding these standards and suggestions regarding new standards should be brought to the attention of the Bureau, so that changes may be made from time to time. Numerous changes proposed by mine operators and by State mining departments have been incorporated in these standards."

May 1, 1944

By G. H. K. Schenck

Weather changes of a daily, weekly, or seasonal period affect mineral production and cause significant losses that are considered unavoidable. Private weather forecasting services are available on a contract basis that can significantly reduce the uncertainty associated with weather-induced changes in the production of and demand for minerals. This paper provides examples of current practice and reviews the opportunities that await those producers who incorporate weather services as an integral part of their operating, scheduling, and planning procedures. Private weather forecasts can be highly accurate because atmospheric trends such as conditions and movement tend to persist and are related to previous meteorological events. Commercial meteorological services are prepared to deal specifically with a mineral producer's special problems (Table 1). Tactical use of private forecasts is a major advance over the severely restricted value of public forecasts which, of necessity, are general in nature and cover a dispersed geographic territory. Private weather services provided on a consulting fee basis offer the mineral producer the opportunity for tactical and strategic response to weather conditions at an acceptable cost. This contrasts with the too-frequent current tendency to view weather as a random variable the costs of which are unknown and about which nothing can be done.

Jan 1, 1970

By Xuanxue Mo, Kaihui Yang

"Abstract- The Laochang mine, located in the Sanjiang area of southwestern Yunnan Province of China, is a volcanogenic massive Pb-Zn-Cu sulfide deposit. It is hosted by a pyroclastic sequence of Barly Carboniferous age, namely the lower member of the Yiliu Group, which was intruded by syenite and rhyolite porphyry . The volcanic suite is basaltic or basaltic-andesitic in composition, has alkaline affinities, and is associated with the initial rifting along the margin of the Baoshan-Shanstate continental rnicroplate (Yang, 1989). The ores are typically Pb>Zn>Cu in composition, averaging 3.820Jo Pb, 3.51% Zn, from 0.01% to 1.85% Cu (0.107% av.), a high average content of Ag (113 g/t) and recoverable amounts of Au, Tl, Gd, Ga, Ge, In. A massive sulflde zone, in which lenticular and stratiform orebodies are localized in a sulflde-carbonate-silica shale unit or sulfldic tufflte horizon that usually overlies coarse-grained pyroclastic rocks, is underlain by a stringer sulflde zone developed in a subvolcanic intrusion or volcanic sequence. The sulfide mineral assemblages, from the top to the bottom of the deposit, are: realgar + orpiment - galena + sphalerite + pyrite- chalcopyrite + pyrite + pyrrhotite + arsenopyrite. Oxide and sulfate minerais occur rarely in the massive ores. The massive ores are generally fine-grained and banded, but coarse-grained ore, colloform and framboidal texture, and growth-zoned pyrite and sphalerite are common. Sedimentary features such as graded bedding, brecciated and deformed ore clasts, and chaotically emplaced blocks, are well preserved, indicating that the massive orebodies have undergone slumping and dis­ placement. Alteration is weak in the hanging-wall rocks, but strong in the stringer zone. Two dis­ tinctive alteration zones have been identified: the upper zone, characterized by an assemblage of quartz, carbonates, chlorite, albite, zeolite and sericite, and the lower zone containing diopside, trema­ lite, actinolite, gamet, clinozoisite, and epidote.The general features of the Laochang deposit are in accord with the descriptive mode! of VMS deposits (Lydon, 1984). However, it falls into neither the Zn-Cu group nor the Zn-Pb-Cu group chemically (Franklin et al., 1981). The depositional setting of the Laochang deposit is quite different from Cyprus or Besshi-type massive sulfide deposits. Laochang is hosted by alkaline lavas that were erupted in a submarine continental rift. Although some features of the Laochang deposit are similar to those of Kuroko-type deposits, there are remarkable differences in the alteration mineral assemblage, the proportion of ore-forming elements (lead enriched) and the amounts of oxides and sulfates. These suggest corresponding differences in ore fluid composition and the associated ore-forming environment. Thus, the authors suggest that the Laochang deposit may be a distinct type of VMS deposit."

Jan 1, 1993

By R. Frenette, A. W. Mo, H. A. Hamza

Fine particles present major technical and economic problems to those who deal with solid/liquid separation processes. In the coal industry the problem is compounded by the large amounts of produced fines such as those present in Western Canadian coals. Flocculants in the form of high molecular weight water soluble polymers are commonly considered an effective solution for the enhancement of the separation process. These reagents are relatively expensive especially when considering a low-price commodity such as coal. Optimization of the use of these reagents is therefore an operational necessity. Six polymers were evaluated as to their effectiveness in flocculating a fine coal tailing. Results were compared with those for a reference flocculant, in-use at that time in the washery. It was shown that, in general, flocculants significantly improve the solid/liquid separation process. The ranking of the flocculants as to their effectiveness in settling and filtration indicated that the best flocculants for settling were not necessarily the most effective for filtration. Flocculants that showed the best filtration improvement were generally cationic and those best for settling were anionic.

Jan 1, 1988

Studies were carried out to examine the effect of introducing varying levels of a pisolitic limonite (Yandi) into an Australian iron ore blend. Compared with other ores in the blend Yandi is more porous. This structure is found to have a considerable effect on the sintering behaviour of the blends. Pilot-scale sintering studies and plant trials showed that sinter plant productivity, sinter reducibility and the low-temperature reduction degradation index altered significantly when the level of Yandi in the ore blend exceeded 15 wt%. The improvement in the reducibility is thought to be a direct result of increased porosity in the sinter and the presence of highly reducible pseudo-relict haematite. Plant trials have also shown that operational changes could be made to the sinter plant to avoid potential deterioration of productivity

Dec 1, 1991

By Serhat Özdemir, Derya Öz Aksoy, Pınar Aytar Çelik, Ahmet Çabuk, Sabiha Koca, Hüseyin Koca

In carbonate flotation, oleate has been used for many years as a collector in industrial scale. Compared to sulfide minerals, the flotation of carbonate minerals requires more collector consumption and has lower yield and selectivity. It has been previously shown that surfactin provides higher yields in smaller amounts than oleate in the bioflotation of calcite as one of the carbonate minerals. In this study, the usability of surfactin as a flotation collector for magnesite was investigated. For this purpose, the adsorption of surfactin on the magnesite surface was inspected with analyses such as FTIR, SEM–EDS, contact angle, and zeta potential measurements. In addition, the effect of surfactin on the surface tension of water was also revealed. The same analyses were also performed for oleate as a reference point. All flotation experiments were performed without optimizing with both collectors. FTIR results showed that the surfactin, like oleate, was chemically adsorbed on the magnesite surface. Surface tension analyses showed that the surface tension of water decreased to approximately 32 N m− 1 at 10− 4 M oleate concentration, and this value decreased to below 25 N m− 1 at the same surfactin concentration. According to contact angle measurement results, the contact angle of magnesite was 85° after the surfactin adsorption of 2 × 10− 4 M concentration, while this value remained at 46° for oleate. Finally, according to flotation experiments, high temperatures and high collector dosages are necessary for acceptable flotation recovery with oleate, yet surfactin can produce the desired result at ambient temperatures and lower collector amounts.

Dec 13, 2022

By Heine Kenworthy

In 1930 the Shenandoah-Dives Mining Co. near Silverton, Colo., put into operation a newly erected, 300-ton selective flotation plant to mill complex ores from its nearby mine. The operation was a steady producer and was enlarged to treat 600 to 800 tons a day. In 1942 the company opened and started milling an area in the mine containing semioxidized ore. The valuable mineral. Content of this ore was considerably higher than in the straight sulfide ore previously handled alone. The mixture of clean sulfide and semi-oxidized ore was difficult to treat; consequently tailing losses, especially with respect to lead, were high. A. few years later, in order to study the possibilities, of obtaining higher recoveries by a modification of the mill flow sheet, a 1,200-pound sample of mill feed, taken over a period of several days by the company, was submitted to the Mississippi Valley Experiment Station for testing. Although this sample proved to contain more than twice as much lead as the average yearly mill feed, the same problem of recovering the oxidized values were present.

Jan 1, 1948

By M I. Pownceby, J Manuel, S Suthers, A Poliakov, E Donskoi, N Ware

"The mining industry is constantly seeking methods for optimising the exploitation of mineral resources, such as iron ore, in a sustainable and eco-efficient manner for economic and social benefit. When faced with resources that have mineralogical or textural complexity, poorer grades or geological variability, it is particularly important to apply a comprehensive geometallurgical approach to the development of the mining operation, from resource definition through to processed product. Integral to this approach is the quantitative characterisation of representative samples across the whole orebody.A key factor that associates the geological characteristics of iron ores to their processing response is ore texture. While the classification of samples on the basis of chemical or physical properties alone is often not sufficient to predict their processing behaviour, classification and quantification of texture types can be effectively correlated to metallurgical performance in processes such as blending, beneficiation, pellet making, sintering and ironmaking. This paper describes some of the research conducted by CSIRO pertaining to the design and rationale of a texture-based classification system for Australian iron ores; some of the tools developed and used to apply such classification; and the application of the generated data to quantifying, modelling and predicting sintering behaviour and performance in the blast furnace.CITATION:Suthers, S, Pownceby, M I, Manuel, J, Ware, N, Donskoi, E and Poliakov, A, 2016. Geometallurgical Characterisation of Australian Iron Ores – from Ore to Processed Product, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 351–360 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By Doxford CI, Perry AJ

Mining Lease 908, situated on Gorge Creek near its confluence with the present Cape River system, has been subjected to intensive recent exploration for alluvial gold.The gold is hosted by a buried palaeochannel, the Gorge Creek Lead and by an overlying remnant meander of the Cape River. The principal, if not sole, sources of gold within the Gorge Creek Lead are the northwest trending Great Australian Reef and Green's Specimen Reef systems which are situated on adjacent high ground. Lower grade gold bearing eluvial ground separates the reefs from the Gorge Creek Lead. The sources for gold within the old Cape River system channel (Canton Lead) are thought to be situated some distance upstream, one source perhaps being the Lolworth Diggings located 30 kilometres to the northwest.Exploration of previously "heavily dug" ground on both leads consisted of detailed geological mapping followed by the collection and treatment of bulk samples from eight costeans. The wash samples varied in size from 120 to 396 cubic metres. Treatment was undertaken through a commercial sized conventional wet screen and jig plant.

Jan 1, 1986

By Steve Signer

Researchers at the National Institute for Occupational Safety and Health (NIOSH) have developed several new tools for evaluating roof support performance. A miniature data acquisition system (MIDAS) was developed that can collect readings from up to 16 strain gauges at regular time intervals and store the readings for later retrieval. Three LED lights change from green to yellow, then red, based on the reading levels and/or rates of change of rock movement. This feature can be used to warn miners of rock instabilities. The system can be used with any strain-gauged support (resin bolt, friction bolt, cable bolt) or with a newly developed rock strain strip (ROSS) developed by NIOSH to measure rock strain. A ROSS is grouted in a hole drilled adjacent to the rock support to be evaluated; the deformed shape of the ROSS provides anchorage on either side of the strain gauges. Data from both laboratory tests and field evaluations are presented that describe the capabilities of both the MIDAS and ROSS instruments.

Jan 1, 2003

By Rodney L. Stone

As part of an overall laboratory and plant test program to determine mixing and other techniques relating to the more economic use of bentonite as an iron ore pellet binder, a settling test was developed for measuring the bentonite content within a pellet or within a batch of pellets. Between pellet batches, each containing a different level of bentonite, the dry fracture load is directly proportional to the bentonite content between pellets of the same batch, however, the fracture load is inversely proportional to the bentonite level; this is explained by a negative correlation between a pellet's size and its bentonite content and the fact that larger pellets can withstand a higher fracture load than the smaller.

Jan 1, 1968

Purification of Nickel and Cobalt from Heap Leaching Effluents Using Ion Exchange Resins A comparative study among several chelating resins for purification of a heap leaching effluent from a nickel laterite ore has been finished. Chelating resins with iminodiacetate (IDA) and bis-picolylamine (Bis-PA) functional groups, from different suppliers, have been evaluated for their selectivity and loading capacities for nickel and cobalt over impurities. The two evaluated IDA resins, Amberlite IRC 748 and Monoplus TP 207, showed very similar results for both loading capacity and selectivity. Better performance was obtained at 7 BV/h at a pH of 4. Evaluation of Bis-PA resin showed that XUS 43578 has better performance than TP 220, with a 30 per cent higher loading capacity and superior selectivity for nickel over impurities.

Sep 13, 2010

By Claudio Flores Martinez

The prospect of accomplishing economically and scientifically profitable deep-sea mineral mining within this decade or the next one is of particular interest to the emerging discipline of astrobiology which is concerned with the origin, distribution and future of life in the Universe. Several planetary bodies within our own Solar System such as Jupiter’s moon Europa and Saturn’s Enceladus now appear to be potentially habitable, or life-friendly, in terms of the three prerequisites for life as we know it: a sustained body of liquid water, biogenic elements (C, H, N, O, P, S) and energy sources to fuel metabolic reactions. Europa, for instance, possesses a global subsurface ocean, believed to be up to 100 km in depth, hidden beneath a kilometer-wide ice-sheet. A silicate mantle is directly interacting with a cold, aphotic ocean in which tidal forces might drive geological seafloor activity that results in the creation of hydrothermal systems. These locales are commonly hypothesized to be the cradles for an alternate origin of life on Europa. Especially alkaline hydrothermal springs, as found at Lost City, have been at the center of modeling the prebiological evolutionary dynamics preceding cellular life. Serpentinization-like reactions are also possibly fueling metabolic networks in putative microbial communities found in the oceans of the icy moos. Major space agencies around the globe are planning future space missions aimed at exploring and eventually characterizing potential life forms in these habitats. The technology needed for this exploration effort resembles the requirements for a successful deep-sea mineral mining industry: highly efficient AUVs (also equipped with biologically-oriented instrumentation), swarm robotics, landers, seafloor rovers and general high-pressure, cold temperature extreme environment engineering. Interestingly, science questions of deep-sea mineral mining and astrobiology converge too: the hypothesis of life originating at hydrothermal systems, the biogeographical distribution of species among these environments, adaptations of extremophilic organisms across the three domains of life and adequate autonomous robotic systems to assess the complexity of deep-sea biological communities. This presentation attempts to present a two-fold view of advanced planetary exploration that relates to a sustainable vision of deep-sea mineral mining: charting our oceans and developing technologies least harmful to endemic biology can propel the design and prototyping of future robotic planetary probes bound for aquatic missions on alien moons. Space industry, government and public interest towards a broadened planetary perspective on deep-sea mineral mining is promoted by addressing an astrobiological rationale of this endeavor.

Sep 1, 2014

By J. S. Hall

The performance of a full-scale balling drum circuit is well known to fluctuate, and is difficult to control. The fluctuations stem from causes that are not readily quantifiable. Results from plant tests show that surging of the recycle tonnage is dependent, inter alia, on the method of bentonite addition, small variations in drum or cutter bar speed and the method of drum water addition. This paper presents detailed observations from experiments on full-scale drum circuits, including preliminary results of a computer measurement and control scheme. Size distributions measured at points along an industrial drum are presented, together with the results of a mathematical model fitted to one plant data set. Model predictions are also included emphasizing the importance of screen performance on circuit stability.

Jan 1, 1983

By C. O. Stee

IN the October, 1936, issue of the Canadian Mining Journal there was published a series of very comprehensive and exccellently illustrated papers by Mr. C. O. Stee and members of his staff dealing with Siscoe operations and ore-bodies. These were, in the order in which they appeared: Geology of Siscoe Gold Mine, by O. L. BACKMAN Diesel Power at Siscoe Gold Mines, Ltd., by C. O. STEE andE. A. BLOMQUIST Mining at Siscoe, by L. T. POSTLE and W. F. Engineering and Surveying, Siscoe Milling Practice, Research and Testing Laboratory, Assaying of Mill Tails and Solutions, BROWN(6) by P. A. TEEPLE (7) by L. E. DJINGHEUZTAN by L. RIVETT (8) by G. IRWIN (9) The Editor of the Canadian Mining Journal cordially assented to our suggestion that these papers be reviewed at the 1937 Annual General Meeting of the Institute, and the authors very kindly accepted our invitation to present such reviews . Of these courtesies, full acknowledgment is here accorded. To our readers, we commend the original papers in the Canadian Mining Journal. The summaries presented at the meeting follow. EDITOR. THE GEOGLY OF THE SISCOE MINE The Siscoe gold deposits lie in and near a stock of granodiorite, related to the Bourlamaque batholith, which has intruded highly folded Keewatin volcanic rocks .. The volcanic rocks lie to the north of a belt of Timiskaming sediments.

Jan 1, 1937

By E. G. Charlesworth, M. J. Robertson

"Abstract - Gold mineralization in the Main Reef Complex at Sheba Gold Mine is hosted within shear zones in a sequence of shales and greywackes of the Fig Tree Group. Competency contrasts between these rocks and a steeply dipping chert unit provided a locus for the development of right lateral steeply dipping shear zones. A set of flatter dipping shear fractures crosscut these zones with their intersections defining a system of en échelon ore shoots.Mineralization is both of vein type and disseminated strata-controlled replacement type. The latter occurs mainly within the wall rocks to the shear zones. Arsenopyrite and pyrite are the major sulfides, with arsenopyrite being confined largely to greywacke beds and pyrite to the more iron-rich shale units. Gold was introduced, together with minor sphalerite, pyrrhotite, chalcopyrite and early arsenopyrite, toward the end stages of a first pyrite phase. The mineralizing fluids were introduced along dilated cleavage planes and, emanating from these, produced a series of replacement fronts. Mineralization was syntectonic to late tectonic and occurred under conditions of progressive deformation, resulting in sulfides which are concentrated in the hinges of shear-related folds and semi­ massive sulfides within tension fractures which are folded, attenuated and fractured .An analysis of the structures shows a sequence of events in which an initial ductile simple-shear event with a steep sense of movement was succeeded by a more brittle strike-slip event. Mineralization is temporally related to the latter. This evolution in structural style was probably related to reactivation of the Sheba Fault as a transcurrent fault during emplacement of large granitoid bodies."

Jan 1, 1994

By W. Mueller, M. Rocheleau, E. Dimroth

The paleogeographic evolution of the Abitibi Belt is subdivided into three phases, namely: 1) a phase of the growth of a submarine volcanic chain, 2) a phase of the emergence and growth of volcanic islands and 3) a phase of uplif t and erosion of volcanic islands. Isostatic calculations suggest that the volcanic sequence in the south of the Abitibi Belt rests on oceanic basement or on the mantle; the volcanic sequence in the north of the belt rests on about 13-14 km of tonalitic basement. 10-15 km of plutonic material accreted to the volcanic islands during paleogeographic phases 1 and 2, and caused the uplif t during paleogeographic phase 3.

Jan 1, 1984