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By W. L. Zeigler

The mill is a departure from gravity concentration and has gained a reputation for the low initial cost of erection, extreme simplicity and the low cost of milling on the refractory character of the ore which is treated. The structure is of heavy timbers with board walls and corrugated roofing. The floors are concrete and the general layout is of the ground floor only. All the machines are driven by individual motors and the transmission usually found in such a plant is entirely absent. (Fig. 2.) ORE The ore from the Galena mine is sheared Wallace quartzite replaced with quartz, siderite, pyrite, sphalerite, gray copper (tetrahedrite) and very fine-grained argentiferous galena. Much of the silver is undoubtedly associated with the gray copper, the amount, however, apparently varies with different localities in the vein. An average assay of the ore is 6.0 per cent. lead, 1.3 per cent. zinc, 0.3 per cent. copper, 17.5 per cent. iron and 4.5 oz. silver. The concentrates produced are of an average 53 per cent. lead, 40 oz. silver, 8 per cent. zinc and 11 per cent. iron, while the tailings are 0.5 per cent. lead, 0.4 oz. silver. With the present market for zinc no attempt is made to produce a zinc concentrate.

Jan 1, 1927

By Robert B. Parsons

"A t last the legal red tape which has tied up flow-through share financing has been cut. New rules effective for deals signed after 1986 simplify flow-through financing by removing the necessity f or cumbersome agency relationships. But there is no free lunch-the new rules require increased government reporting. And beware federal tax reform promises to have a good look at the new flow-through share rules. IntroductionFlow-through shares have always worked better in theory then reality as an effective financing tool. The concept is straightforward: a transfer of risks, tax deductions, and potential returns. But the mechanics of the old flow-through rules made the transfer of risk impractical to impossible by placing the responsibility for incurring Canadian exploration expense (CEE) on investors. The new rules are significantly more realistic, shifting that responsibility to the issuing corporation. However, every silver lining must have a few clouds around it. In the case of the new flow-through rules, the more obvious negatives are increased reporting requirements and reductions in CEE eligible for flow-through by amounts of assistance received. The new rules are effective for deals signed after 1986, however, so a few old-style deals are still around. Practical Difficulties with Old RulesThe old rules which applied to investments in flow-through shares were structured so as to make it the responsibility of the investor, rather than the issuing corporation, to perform the Canadian exploration expense for flow-through. Since most investors had neither the expertise nor the inclination to incur the CEE, this requirement necessitated the use of cumbersome arrangements whereby the investors would appoint an agent (usually the issuing corporation) to incur CEE on their behalf. Although the issuing corporation might consequently be the party which actually spends the flow-through share funds on CEE, the awkward legal structure of such an arrangement made the investor the ""principal"" incurring the CEE. As such, the requirements of the old rules were met and the investors could receive their flow-through share s."

Jan 1, 1987

By P. L. Swanson, A. T. Iannacchione, W. J. Gale

This paper outlines the concepts used to correlate rock failure with microseismic events and presents examples of microseismic monitoring together with associated computer modelling of the rock failure. This study is motivated by the need to develop improved ways to reduce ground control hazards in underground mining. Toward this end we present and compare results from numerical modelling and micro- seismic monitoring studies conducted at several different mine sites. Emphasis is on integrating results obtained with these tools to characterize, and thus increase our understanding of, important mine deformation processes. The ultimate goal is to use this knowledge to design mine structures, and develop mitigation measures, that minimize specific ground control hazards.

Jan 1, 1967

By L. W. Holm, G. G. Bernard

Laboratory experiments were conducted to determine the effect of foam on gas flow in porous media. Previous studies have indicated that foam may be applicable as a restrictive agent in influencing underground gas flow. Foam was found to be exceedingly effective in reducing the permeability of porous media to gas. Consolidated and unconsolidated sands with specific permeabilities of 100 to 146,000 md had, in the presence of foam, gas permeabilities that were less than 1 per cent of the specific permeability; in many cases the gas permeability was practically zero. Foam reduced the gas permeability of loose sand to a much greater degree than that of a tight sand. For example, the permeability of a 125,000-md sand was reduced to 3 md while the permeability of a 4,000-md sand was reduced to 7 md. This effect should cause, to some degree, selective plugging of high permeability channels in various oil displacement processes. The presence of oil in a porous medium decreased the effectiveness of foam in reducing gas permeability; apparently oil acts as a foam depressant. However, it was found that certain foaming agents were very effective in reducing permeability even. in the presence of oil. Also, continuous injection of other foaming agents increased their effectiveness, when oil was present. The effect of foam on permeability of porous media to gas was studied as a function of foaming agent concentration and injection rate, absolute permeability, total pressure, pressure gadient, length of porous system, brine concentration and time. INTRODUCTION The use of surface active agents in flood water to increase the recovery of oil has been studied in the laboratory and in the field for decades, with rather limited success. In recent years a new approach to the problem was proposed. Instead of using an aqueous solution of surfactant as an oil recovery agent, Bond and Holbrook2 proposed that the oil recovery agent be a mixture of surfactant solution and gas. In their method, a water-soluble surface active agent with foam-producing characteristics is injected into an underground formation as an aqueous slug. This slug is followed by gas to produce a foam within the rock. Foams are defined as "agglomerations of gas bubbles separated from each other by thin liquid films'! A foam is fundamentally an unstable system. The foam process for oil recovery has since been studied by other investigators. Fried 1 has shown that foam can displace from porous structures oil that normally is unrecoverable by conventional water or gas drives. This superior oil displacing action is believed to be the result of several factors: (1) foam introduces into the reservoir many resilient interfaces of various sizes and curvatures, which increase the probability that a proper combination of forces for oil displacement will be created; (2) foam has appreciable viscosity which improves mobility ratio and contact efficiency; (3) foam accentuates the trapped gas effect because high gas saturations are possible without producing high gas/oil ratios. Deming4 studied the effect of various foam properties on the displacement of liquid. He found that (1) high foaming ability favors high displacement efficiency; (2) high foam stability is not necessary for high displacement efficiency; (3) displacement efficiency decreases with increase in plasticity of foam and (4) displacement efficiency is unaffected by surface tension of foaming agent solution. One of the important aspects of this oil recovery process is the effect of foam on gas permeability. The simultaneous flow of gas and liquid in porous media has been studied by numerous investigators and a large amount of literature exists on the subject. In this previous work, gas and liquid have generally been considered as essentially independent phases, whose flow characteristics are related through the saturation parameter. Foam, however, is a material with properties that are considerably different from those of its components; for example, the viscosity of a foam is greater than either of its components. Gas flow in a porous medium in the presence of foam should be considerably different

Jan 1, 1965

By G. Prabhulingaiah, D. M. R. Sekhar

"A phosphate deposit of estimated 6 billion tons of P2O5 is located 180 to 300 meters below the sea level, 185 kilometers north of port Luderitz, Namibia. The ore bed is 6 kilometers wide and 220 kilometers long. The ore deposit analyzing 16% P2O5 is loose sediment of 1.5 meters thick without over burden. Sizing of the ore to - 1.4 mm + 0.150 mm improves the grade to 23.54% P2O5 with a P2O5 recovery at 83.75% containing phosphate pellets and flakes of sea shells. Clay, bacterial debris as organic matter, flakes of broken sea shells and fine phosphate containing particles report to - 0.150 mm fraction and + 1.4 mm fraction contains sea shells and few phosphate containing pellets. The mineralogical composition of phosphate containing pellets is estimated (Droste, T.C., 2004) 80% frankolite, 6% pyrite, 4% illite, 3% quartz, 3% amorphous SiO2, 1% carbonates, 1% organic carbon and = 1% ilmenite, magnetite, zircon etc. The phosphate content in the pellets is around 27.7% P2O5. Trials to separate by gravity or flotation processes were not successful. Leaching of carbonates (sea shell flakes) under mild acidic condition (= 2% acetic acid or HCl solutions) or calcinations followed by leaching however yielded residues (concentrates) of grades 27.85 - 32.74% P2O5 at P2O5 recoveries ranging from 78.45 - 96.8% P2O5."

Jan 1, 2014

By Raja V. Ramani, Robert L. Frantz

"The House/Senate Joint Conference Committee has instructed the Bureau of Mines to have the Advisory Committee on Mining and Mineral Resources Research review on an annual and simultaneous basis each generic mineral technology research center (GMTC). In order to accomplish that review promptly and uniformly, committee members have revised and approved an in-depth questionnaire. That document formed the basis of their review. The information provided by that questionnaire was an important factor in their recommendations concerning the future direction of the program; a presentation was made at the last National Plan Update.The comprehensive nature of the questionnaire and the scope of the information contained therein make it an excellent retrospective of the Center. Having a clear vision of where the Center has been and knowing where it is now will help guide it into the future. It is felt that such a detailed view of the Center's facilities and research program will be of value to Center personnel and Advisory Committee members.Each aspect of the questionnaire has been examined, answered in detail, and documented throughly. With the completed questionnaire as a guide, this volume examines the research program, Center personnel presently active on GMTC projects, number of graduate degrees granted with GMTC support, GMTC publications, degree of individual interaction, technology transfer, the reference center, GMTC equipment and facilities, and any envisioned plans for future research. It is hoped that this volume will serve as a review of the years 1984-1988, the first four years of the Center's operation."

Aug 31, 1989

By D. J. Brown

Froth flotation is now used to recover millions of tons of fine coal,(-1/2 mm), every year. For example, in Great Britain, 4-million tons of flotation concentrate was produced in 1960, about 3% of the mechanically cleaned out- put and 2% of the total salable output. Coal flotation is not so widely practiced in the U. S. as it is in Europe since much American coal occurs in thick seams of high grade and does not require cleaning. However, in the U. S., as elsewhere, the increasing mechanization of coal mining machinery has lead to a lowering in size and grade of product from the mine and to an increasing need for cleaning of coal to improve the grade before sale. With an increasing proportion of fines in the product, froth flotation has assumed a greater importance as a cleaning process for coal. In the last three years, over 40 flotation plants have been put into operation in the Appalachian area of the U. S.80 Fine coal recovered by means of froth flotation may be used as a powdered fuel alone or mixed with coarser grades. The removal of this fine coal from washery water makes possible the recirculation and re-use of the water and also leads to improved and more consistent operation of jigs and other separating machines which function less effectively when there is a build-up of fine solids in the washery water. Finally, froth flotation is of assistance in the production of a clarified effluent which may be discharged from the washery without polluting local rivers, streams, or wells. The 1961 cost of installing a new coal flotation plant in Great Britain would be about $19,000 per ton of dry solids input per hour, including the cost of new buildings and coal and shale filtration and water clarification equipment. The figure for the gravity concentration of the large coal, the main plant, would be about $4,800 per tph. The operating cost for the new coal flotation plant would be about $1.10 per ton. Even at this level of cost the cleaning operation is economic in Great Britain for coking coals. In the U. S., a froth flotation cost of 14$per ton of cleanfilter cake was quoted early in 1958 for one operation,l though admittedly this was a special case. Assuming a cake moisture con- tent of 30%, it is estimated that this cost is equivalent to a figure of 256 per ton of dry solids input, for the incorporation of coal flotation in an existing washery. A cost oh 416 per ton of concentrate was quoted76 in a recent analysis of flotation economics, this cost being brought up to $1.11 per ton after payment of royalty, welfare and association dues and taxes. Capital cost was $120,000 for a plant producing 133 tpd of concentrate. Before considering the treatment of coal by flotation it is appropriate to survey some of the properties of coal which are of importance in the process.

Jan 1, 1962

By Sandra L. Maxfield, Alan Mair

Strategic design of groundwater monitoring programs can increase public confidence in mine management, decrease financial assurance requirements, and minimize environmental budgets. Monitoring of inorganics is challenging because many occur naturally with baseline concentrations fluctuating spatially or temporally. Evaluating monitoring data to distinguish between a hazardous release or a natural fluctuation in baseline concentration can be controversial. In order to develop an effective program, monitoring parameters should be selected which are mobile and stable. Statistical procedures should be customized to address the uniqueness of groundwater systems. Calculated baseline concentrations should minimize the false negative & false positive rate.

Jan 1, 1995

By Charles A. Maliszewski, James M. Galvin, Gerhard Urschitz

With obvious signs of deterioration, the double track, historically registered Bergen Tunnels as part of the commuter rail system in New Jersey waited for rehabilitation for a long time. Serious water in filtration not only caused operational and safety hazards for the electrified rail line but also deteriorated and structurally compromised the tunnel lining. An innovative rehabilitation program was developed to enlarge the tunnel and to provide a new waterproofing system and final lining. For the rock excavation and support New Austrian Tunneling Method (NATM) principles were utilized, while water tightness was achieved by installing a PVC membrane waterproofing system followed by a reinforced cast-in-place final lining. Experienced on-site supervision generated additional savings during construction by streamlining support elements based on geologic conditions encountered.

Jan 1, 2003

By K. C. Liddell

Chemical processing research made notable advances during 1986. This overview is necessarily brief. It is intended, though, to give the flavor of selected areas where recent activity has been high. At the 1986 Annual Meeting of The Metallurgical Society, a symposium was held on hydrometallurgical reactor design and kinetics. R. G. Bautista, R. J. Wesely, and G. W. Warren edited the resultant proceedings volume. This is the first available volume on this subject. It includes 26 papers on fundamental kinetic studies, modeling of reaction kinetics and reactor performance, and pilot and production-scale operations. Metals discussed include silver, gold, platinum, titanium, cobalt, nickel, zinc, copper, manganese, and iron. Agitated tanks, heaps, dumps, pachucas, pressure auto-claves, electrolytic reactors, liquid membranes, and fluidized beds are among the reactor types covered. An international symposium dealt with iron control in hydrometallurgy. It was sponsored by the Metallurgical Society of CIM, the Institution of Mining and Metallurgy, The Metallurgical Society of AIME, and Gesellschaft Deutscher Metallhutten and Bergleute. J. E. Dutrizac and A. J. Monhemius edited a proceedings volume containing 41 papers. These covered many areas of process chemistry, solvent extraction, precipitation, treatment of pickle liquors, impurities, residues and the environment, and process selection. Precious metals Concerning precious metals processing, the US Bureau of Mines IC 9059 is noteworthy. It includes papers presented at a USBM briefing at the Western Mining Conference in Denver. Topics covered included ion exchange, staged heap-leaching direct-electrowinning, and mercury precipitation during cyanide leaching of gold ores. Also dealt with were carbonaceous gold ores, carbon adsorption and desorption, heap leaching, the carbon-in-pulp process, and precious metals recovery from electronic scrap and solder. R. C. Sandberg and J. L. Huiatt (Journal of Metals, June 1986, and USBM RI 9022) developed a method to recover silver, gold, and lead from a complex sulfide using ferric chloride, thiourea, and brine-leach solutions. Gallium Gallium recovery was also a subject of considerable interest. Much information on this topic is proprietary. But two papers described solvent extraction of gallium. V. P. Judin and R. G. Bautista (Metallurgical Transactions B, 1986) developed an equilibrium model to separate gallium chloride from aluminum chloride. Tributyl phosphate was the extractant studied. T. Sato and H. Oishi (Hydrometallurgy, 16, 1986) investigated gallium extraction from sodium hydroxide by using Kelex 100. Data were given on the equilibrium distribution and the extraction kinetics. Galena Interest continues in recovering lead by hydrometallurgical processing of galena. J. E. Dutrizac; S. H. Kim, H. Henein, and G. W. Warren; and M. C. Fuerstenau et al. (Metallurgical Transactions B, 1986) all investigated leaching of PbS by ferric chloride. Dutrizac reported parabolic kinetics and reaction control by outward diffusion of lead through a porous layer of elemental sulfur. Kim, Henein, and Warren, however, reported that two leaching reactions occur. A nonoxidative reaction produces H2S and there is an oxidative leaching by ferric ion. Acid dissolution was found to predominate when the acid activity to ferric activity ratio is high. Surface chemical reaction was reported to be controlling. Fuerstenau et al. also reported that mass transfer through the sulfur layer is rate determining. But they believe that the species transferred are chloro complexes of ferric ion. In other work on lead, A. Y. Lee, A. M. Wethington, and E. R. Cole, Jr. of the USBM described an environmentally acceptable hydrometallurgical alternative to the smelting of lead concentrates (RI 9055). Uranium In spite of depressed prices, much work has been reported on uranium processing. R. G. L. McCready, D. Wadden, and A. March-bank (Hydrometallurgy 17, 1986) described the nutrient needs for in-place leaching by T. ferrooxidans. They reported the optimal conditions for uranium solubilization. L. E. Eary, H. L. Barnes, and L. M. Cathles (Metallurgical Transactions B, 1986) carried out an experimental and modeling study of uraninite dissolution. They concluded that ferric ion preferentially leaches uraninite in pyritic ores. Hydrogen peroxide was found to be less selective. A. Vuorinen, P. Hiltunen, and O. H. Tuovinen (Hydrometallurgy 15, 1986) studied redox and precipitation reactions of iron and uranium in leach liquors. P. T. Chiang (Hydrometallurgy 17, 1986) reported on the effect of uranium loading in the DEPA-TOPO process to separate uranium and iron from wet-process phosphoric acid. F. J. Hurst (Hydrometallurgy 16, 1986) conducted a fundamental study of the separation of uranium from phosphoric acid by DEPA and TOPO. D. E. Chia and W. C. Cooper (Hydrometallurgy 16, 1986) reported on bench and pilot scale work to recover uranium by the HIMIX process. They reported that the acid consumption to produce an eluate suitable for yellowcake

Jan 5, 1987

By Isaac A. Zlochower, Kenneth L. Cashdollar

The Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) conducted a study of the explosibility of various metals and other elemental dusts, with a focus on the experimental explosion temperatures. The data are useful for understanding the basics of dust cloud combustion, as well as for evaluating explosion hazards in the minerals and metals processing industries. The dusts studied included boron, carbon, magnesium, aluminum, silicon, sulfur, titanium, chromium, iron, nickel, copper, zinc, niobium, molybdenum, tin, hafnium, tantalum, tungsten, and lead. The dusts were chosen to cover a wide range of physical properties-from the more volatile materials such as magnesium, aluminum, sulfur, and zinc to the highly "refractory" elements such as carbon, niobium, molybdenum, tantalum, and tungsten. These flammability studies were conducted in a 20-L chamber, using strong pyrotechnic ignitors. A unique multiwavelength infrared pyrometer was used to measure the temperatures. For the elemental dusts studied, all ignited and burned as air-dispersed dust clouds except for nickel, copper, molybdenum, and lead. The measured maximum explosion temperatures ranged from "-1550K for tin and tungsten powders to "-2800K for aluminum, magnesium, and titanium powders. The measured temperatures are compared to the calculated, adiabatic flame temperatures.

By A. A. Collins

When we speak of high copper on a lead blast furnace we think in terms of 4 to 5 pct, or. any lead charge carrying over 1 pct. Any copper on charge will produce its corresponding troubles such as lead well, extra slag losses, drossing problems, and the working up of the dross. This is indeed a very interesting subject and one that used to give the old-time lead metallurgists such as Eiler, Hahn and lles many worries, not so much in the actual operation of the hlast furnace but in the working up of the copper. When the American nletallurgists commenced with the American rectangular-shaped lead blast furnace in the 1870's and got away from the reverberatories such as were in use in Germany and other parts of the world, they went to greater tonnages, as 80 to 100 tons per day in comparison to the 20 to 30 tons per day in the other processes. With the greater tonnages along with insuficient settling capacity, the silver losses in some cases were increased. Hence the lead-fall was low, for there were no leady concentrates in those days to assist the metallurgist to gain lead or an absorber for the precious metals; and in some cases copper sulphides were added intentionally to the charge to produce a copper matte to lessen the silver losses through the dump slag. The operators in those days thought that where some copper was always present in the lead ores the copper should not enter into the reduced lead and alloy with it. This, by the way, is just the reverse of our present-day practice, when we try to put all of the copper into the blast furnace lead and to remove the same through the drossing kettles. Therefore the furnace was operated to produce a certain amount of matte or artificial sulphides, since, due to the great affinity of copper for sulphur, any copper present would enter the matte almost completely. Thus, the lead bullion produced was practically free from copper. The products of the furnace were metallic lead or lead bullion, containing 05 to 95 pct of the lead and about 96 pct of the silver which were in the ore—a lead-copper-iron matte which contained nearly all the copper in the ore and the slag, the waste product. In the United States, up through the year 1092, we find the small furnace 100 X 32 1/2 in. with 12 tuyeres, some 6 on each side, plagued with a small amount of poorly roasted sulphides— either from heap or hand roasters that produced matte. This matte was roasted and if poor in copper was returned for the ore smelting. Otherwise it was smelted either alone or with additions of rich slags or argentiferous copper ores, the products being lead and a highly cupriferous matte, the latter being subsequently worked up for its copper. The lead metallurgists kept trying and improving on furnace and roasting equipment designs until we find blalvin W. Iles constructing at the old Globe Plant at Denver what came to be the modern furnace. That is, in 1900 he built a furnace of 42 in. width by 140 in. at the tuyeres with a 10 in. bosh and a 16-ft ore column. This type has been more or less standard to the present time, though modified in width and length to meet the demand for large tonnages and improvements in structural details. In 1905 at Cananea, Mexico, Dwight and Lloyd developed the present down-draft sinter machine that has meant so much in producing a well-processed material for the lead blast furnace. In 1912 Guy C. Riddell came forth with double roasting at the East Helena Plant of the American Smelting and Refining Co., which removed the "zinc mush plague." Incidentally, with the introduction of double roasting, which most lead plants were forced into after 1924, when lead flotation came into its own, less matte or no matte was produced. When this stage arrived, the copper was forced into the dross and the casting of lead at the blast furnace lead-wells was stopped. In plants with a fair copper carry 1 pct or better on the blast furnace charge, the lead wells became inoperative once the production of matte stopped. The copper drosses clogged the lead wells and even with bombing, either water or dynamite, the operators could not keep them open. Thus, the lead wells were abandoned in some plants, such as at the El Paso and Chihuahua smelters of the American Smelting and Refinillg Co., and all lead taken out through the first settlers. The elimination of sulphur, espccially sulphide sulphur, from the blast furnace charge and the nonproductiori of matte resulted in a great saving of tinie, energy and equipment in the recirculation of the copper, With the copper content in the dross and dross-fall ranging in quantities from a few percent up to 60 pct, such as at El Paso, a drossing problem was created. As the old-time operators hated dross and buried the same in the shipping bullion, the modern metallurgists from 1925 on decided that with increasing dross-falls they would have to adopt the lead refiner's ideas of drossing kettles with subsequent treatment of the lead with a sulphur addition to have the shipping lead of 0.01

Jan 1, 1950

By R. L. Virta

Six companies mined fire clay in Missouri and Ohio during 2004. Production, based on a preliminary survey of the fire clay industry, was estimated to be 398 kt(438,700 st), valued at $9.81 million. This was slightly less than the production and value figures from 2003. Missouri was the leading producer state. It accounted for more than 70 percent of the U.S. production. Consumption Domestic producers sold or used fire clay primarily for refractory applications. This application accounted for 79 percent of the market. Refractory products made using fire clay include firebrick and block, grogs, high-alumina brick and specialties, refractory mortars and mixes, and saggers.

Jan 1, 2005

By William Kent

William Kent, Pi.~t~bIJrQh, Pa.: The steel rnanufac.tnret of this country nlust ever he grateful to Dr. Dudley for his painstaking and conscientious endeavor to estaldish the relation between the chemical analysis and the wearing capcity of steel rails. They tnust thank him for the vast array of $acts he presents, and for having given them sixty-four analyses with which to combat his own conclusions and to establish their own, which are entirely opposite to his. In Dr. Duclley" discussion of his former investigation, at the Pittsburgh meeting, he said, "If you do not like my conclusions, draw your own conclusions." I have studied his last paper as thoroughly as the limited time since I received it would adruit, and have drawn some concluvions which I will first state, and then attempt to demonstrate. Briefly stated, my conclusions are: lst, That as far as these 64 analyses reveal anything of service to railmakers and cotsumera, it is that within the following chemical and physical limits, viz., Carbon,..0.20 to 0.60 Pisovphorue ,..0.026 to 0.146 Silicon,.. 0015 to 0.480 BInnganese.......0.262 to 0 880 Phosl~horus un~ts,..20.3 to 6.72 Bending weight,. 2270 lbs. to 4260 Ibs. Drfl~ctinn,.. 13O to 190° or in other words within the limits of rienrly the whole range of the chenlical and bending testa of these 6-2 mils: the wearing capacity bears no relation at all to mrbon, to phosphorus, to silicon, to mnnganese, to phosphorus units, to bending weight or to deflection or if there is any relation between the wearing capacity and thest! six or sr!ven variables, it is so obscured by the action of other cause or variat~les not yet known, that such relation cannot be expressed by any practical formula. 2d. That the difference in wearing capacity of these 64 rails was not due to unrbon, to phosphorus, to silicou, to manganese, or to anj combinntion of these four elements, but that it was due to some other cause or cornbination of causes, of which Dr. Dudley's whole iuvestigtion furnishes 11s no clue whatever. A few of the nlarry possible causes I lnay name : sulphur, copper, oxide of iron inclossl air or other gases, orerblowing, underblowing, oyrhaiting, undcrIreatinp, too hot-finishing, too cold-finishing, cold-straightening, toc great or too litkle rductiun hlu the rail to the ingot, or the portion

Jan 1, 1881

By Christie Myburgh, James Mackenzie, Ross Hammond

Modern mining operations are increasingly characterised by their access to large volumes of data and advanced computational tools. Over the past two decades, the industry has made substantial investments in digital technologies supporting geological modelling, mine planning, equipment dispatch, and process control(Newmon et al., 2010; Paraszczak, 2019). These systems have significantly improved the ability to generate and analyse information across the mining value chain. However, despite these advances, the decisions that ultimately determine operational performance remain largely implicit and unmanaged (Kruger et al., 2023; Jia, 2022). Mining decisions rarely occur in isolation. Decisions made in geology influence resource models, which shape mine plans, production schedules, and downstream processing strategies. These, in turn, affect operational execution. As deposits become deeper, ore grades decline, and operational constraints increase, these interdependencies create increasingly complex decision environments (Newman et al, 2010; Topal, 2008; Darling, 2011; Dimitrakopoulos, 2004). In practice, coordination across these domains often relies on informal communication, iterative meetings, and manual interpretation of analytical outputs. Explicit decision support systems provide a mechanism to capture these dependencies, maintain consistent decision context, and coordinate decision-making across geological, planning, and operational domains (Power, 2002; Shim et al., 2002). This paper argues that a fundamental gap remains in current digital mining systems: while data and analytics are well supported, decision-making itself is not. Addressing this gap requires treating decisions as explicit, structured elements within the operational system. By integrating data, computational analysis, and decision processes, explicit decision support systems offer a way to better coordinate complex, interdependent decisions across mining operations.

May 2, 2026

By P. R. Geoffoy, T. Koulomzine

"The discovery of the Mogador deposit concealed by 100 feet of overburden was the result of combined application of geological reasoning, ground geophysical surveys, studies of glacial float and extensive diamond drilling. The ground was acquired because it lay on the projected intersection of the Manville and Laflamme River faults. Systematic ground prospecting led to discovery of mineralized floats. A first unsuccessful exploration campaign lasted several years and consisted of 137 drill holes.In 1951 the boulder nests were reexamined and an associat'on of the mineralized float with boulders of a granodiorite, unknown in outcrops of the district, was established. Consequently, ground magnetic surveys were extended and re-interpreted, and a large anomaly interpreted as corresponding to a batholith was outlined. The existence of the batholith was immediately confirmed by drilling and the Mogador deposit discovered in third hole of new drilling programme in a zone of fractured volcanics paralleling southern contact of batholith.The Mogador deposit is a complex replacement of silicified volcanics by pyrite, pyrrhotite, sphalerite, chalcopyrite and galena carrying values in silver and gold. A total of 1,230,000 tons has been indicated, most of it now classified as fully developed proven ore."

Jan 1, 1960

By Alexander L. Field

The Bureau of Mines is investigating the problem of slag viscosity, its variation with the temperature and with the composition of the slag, and its effect upon the distribution of the sulphur between molten iron and slag, as introductory to a series of contributions to the theory of the metallurgical processes. The method of measurement, viscosity apparatus, furnace and other accessories mentioned in this paper have been described fully in s Bureau of Mines report.1 The Literature on Slag Viscosity The viscosity of blast-furnace slag had not been measured previous to the investigation described in this report. A number of investigators have determined the "fusibility," or softening temperature, of slags by means of the cone method .or other deformation method, but these methods supply only limited information regarding the temperature-viscosity relations of the slag in question. Any deformation method that may be employed indicates only the temperature at which the slag attains a more or less definite viscosity., the magnitude of the value obtained depending on the method used. For details of the various methods used by different investigators, see the Bureau of Mines paper already referred to. An isolated measurement by Doelter on a single mixture at 1,300" C. represents the highest temperature reached in the various viscosity investigations previous to those described in this report, in which results have been referred to absolute units. Arbitrary deformation tests have of course been made at much higher temperatures.

Jan 1, 1917

By A. M. Bell

"Hallnor mine is in the township of Whitney, Porcupine district. To date, its production of gold has been second largest in the east Porcupine field. Ore was discovered in the property in 1936 by diamond drilling in overburdened country. This drilling was undertaken by Noranda Mines following the discovery of ore in conglomerate at Pamour 1 mile to the east.Milling commenced at the Hallnor in June 1938, and to the end of 1945 432,000 oz. gold had been produced from 889,000 tons of ore, giving an average recovery of 0.49 oz. a ton.The West mine of Pamour, the Broulan orebody, and the veins on the Hallnor and Bonetal are all parts of a mile long vein system that has been separated into three sections by cross faulting. In consequence, they could well have been described in one paper. In treating them individually the viewpoint obtained from each may lead to conflicting opinions, and any conclusions advanced in this paper on the general structure should be modified by the conclusions advanced in papers on the neighbouring properties.GENERAL GEOLOGYRock FormationsThe Hallnor orebodies occur within 400 feet of the contact between lavas and sediments, and may lie in either lavas or sediments. The lavas near the ore consist of flows of pillowed andesite and one flow of more acid and less sheared and chloritized lava locally named trachyte. These flows strike east-west and dip steeply. At the surface on the east side of the property the volcanics have been intensely altered to a massive carbonate rock having a north-south thickness in excess of 1,000 feet . This carbonate body extends west across the property with a plunge of 45° (Fig. 1)."

Jan 1, 1954

By C. Schlumberger, M. Schlumberger

In order to explore electrically a terrain composed of a succession of horizontal beds, a current of known intensity i is caused to flow between two grounds A and B, and the resultant drop of potential , caused by the resistance of the earth, is measured between two given points in the soil, M and N. In practice it is convenient to choose the two points M and N so that they lie on the line AB and their midpoint coincides with the middle 0, of that line, although this is not imperative. When the lengths L and I of the two lines AB and MN are varied, equations are obtained which may be solved for the resistivity p of the subsoil at various depths. Recall briefly that the formula 4 x l gives the average resistivity, in the horizontal direction, of a layer of earth which extends to a depth1 about equal to L/4. This elementary concept is adequate for numerous practical applications. Nevertheless, it must be said that, in many cases, a rigorous mathematical analysis may be made, provided it is always a question of homogeneous, superposed horizontal beds. The authors expect to publish, later on, appropriate methods of calculation for some specific cases.

Jan 1, 1932