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By J. M. Whatley

"IntroductionFEW COUNTRIES equal Canada in the diversity of its mineral output, the range of size of its mine operations, and the extremes of climatic and topographic conditions under which its mining is carried out. Camps large and small are scattered over thousands of miles, some served by excellent communication lines, many in remote regions of the north. Common to most of the deposits is that they are worked by underground methods, and rely on adequate hoisting installations for the success of their operations.Hoisting in some form •pre-dates all other mechanical operations in mines and the hoist remains one of the most important pieces of equipment at the average mine. It provides the single line of communication along which must pass the men and materials to mine the rock, and in turn carry the ore to a place for refinement.Development of Mine Hoists in CanadaCanadian designed hoists were first built and •placed in operation about the year 1880 and have since developed in pace with the rapid growth of the Canadian mining industry. Early machines were all of the steam or compressed-air driven types, of light construction and driven by two duplex slide-valve open-frame type engines. As their application and size increased, designs became more rugged and more efficient."

Jan 1, 1955

By D Connelly

There is now a new generation of mobile crushing and screening plant systems available which have been developed based on the motivation of reducing truck haulage. Newly designed mobile crushing and screening plant systems have the advantages of mobility, flexibility, economy and reliable performance, making this system very appealing for small- to medium-sized projects or projects where a number of resources are separated by distance.A brief review of the past history and experience with transportable crushing plants provides an insight into some of the issues with transportable plants in mineral processing. A closer look at a simple model based on exploiting small but high-grade orebodies suggests the concept has merit, however there are many more engineering, logistics, legal, technical and management aspects which have limited the application of such a concept in the resource sector. This paper explores the concept in detail and endeavours to analyse the preferred commodities and scenarios under which the concept could be used and the economic and logistical limitations for iron ore. The paper also looks at the risk assessment criteria to be applied in selecting the type of resource projects where the model could be applied successfully. Other aspects considered in this paper are the project planning requirements, technical and economic feasibility, bankability and operability. Reference is made to the operating experience of contractors at a number of sites and feedback from the resource companies as managers of the projects.CITATION:Connelly, D, 2013. Mobile crushing and screening plant applications for small- to medium-sized iron ore projects, in Proceedings Iron Ore 20 13, pp 349-354 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By J. S. Hu

FTIR spectroscopy has been used for the characterization of adsorbed oleate at the fluorite surface. It has been found that modest changes in the adsorption density at high temperature and high oxygen potential do not provide a satisfactory explanation for the significant increase in the hydrophobic character of the system under similar conditions. Rather, FTIR spectroscopic measurements suggest that chemical interaction between adsorbed oleyl groups occurs at high temperature and/or oxygen potential and accounts for the increased hydrophobicity. Specifically, the intensity of the =CH bond of the adsorbed oleate diminishes at high temperature and/or high oxygen potential. Such a phenomenon was not observed in control tests with the calcium oleate soap. For extensive reaction at the fluorite surface, the presence of a new surface species has been identified. These results indicate that the fluorite surface catalyzes an oxidation and/or polymerization reaction between adsorbed oleyl groups which results in a more hydrophobic structure at the fluorite surface.

Jan 1, 1986

By S. Park

In a flotation froth (and foam), air bubbles become larger due to coalescence, causing less hydrophobic particles to drop off. A bubble-coarsening model has been developed by calculating the changes in Plateau border area as a function of the initial bubble size at the base of a foam, liquid fraction, and foam height and then relating the predicted Plateau border area to the critical rupture thickness of lamellae film. The model predicts that bubble coarsens with increasing froth height, decreasing frother dosage, and decreasing aeration rate. The model predictions are in good agreement with actual bubble size measurements.

Feb 23, 2014

By Wei Sun, Jaewon Choung, Zhenghe Xu, Zhangming Cui

"High intensity conditioning has been demonstrated in a number of cases to enhance fine particle flotation. The improvement could be attributed to the enhanced formation of particle aggregates. However, the understanding of aggregation mechanisms remains rather limited. Recently, an enhanced particle aggregation was observed by the formation of small air bubbles resulting from high intensity agitations (HIA). In this study, a novel visualization system is designed and constructed for characterizing the fine bubbles formed in an HIA cell. The new design allows determination of gas evolution and bubble size distribution. With this system, the effect of dissolved air on fine bubble generation by HIA is investigated. The results show that HIA creates a favorable environment for the formation of gas nuclei and small size bubbles due to hydrodynamic cavitation.INTRODUCTIONFlotation is a dominant separation technique employed by mineral industry to recover the valuable mineral particles. However, in general, particles finer than approximately 10 µm are not effectively recovered by conventional froth flotation technique due to their low inertia and high specific surface area (Fuerstenau, 1988). Therefore, the fine particle flotation has been considered as the central challenge of flotation research. Substantial advances have been made for fine particle flotation from both a theoretical and technological point of view (Fuerstenau et al., 1979; Song and Lu, 1990; Subrahmanyam and Forssberg, 1990; Sivamohan, 1990; Sedat and Barry, 1991; Matis, 1995). High intensity agitation (HIA), for example, has found some success to improve fine particle flotation kinetics in laboratory tests (Chen et al., 1999a and 1999b; Valderrama and Rubio, 1998; Rubio and De Brum, 1994).The effect of mechanical agitation on flotation kinetics has been recognized for many years. In mid-1970s, Warren (1975) reported that increasing the shear rate of the pulp could improve the efficiency of ultra fine particle flotation. He attributed this improvement in flotation to the formation of aggregates. This concept of aggregation has been extended by Rubio (1978), and Bulatovic and Salter (1989), who employed high intensity agitation (HIA) method to promote aggregation. They found that HIA with the addition of collectors, frothers and suitable modifiers significantly improved both the flotation recovery and selectivity of ultra fine sulphide minerals. The improvement was explained by warren’s shear flocculation theory. Till now, many studies (Chen et al., 1999a and 1999b; Valderrama and Rubio, 1998) have been undertaken to improve fine particle flotation by HIA. However, most of these studies were focused on the relation between energy input and flotation efficiency. Less information was available for describing how the aggregate formed during HIA process."

Jan 1, 2006

By J. R. Hindman

The vermiculite review arrived too late for the June issue. In 1992, production of commercial vermiculite in the United States increased 1 % to 170 kt (187,000 st), according to the US Bureau of Mines. The estimated value of vermiculite concentrate was $13.6 million, yielding an average value of $80/t ($72.50/st). Vermiculite is used in several physical forms. Use of the thermally exfoliated product include light weight aggregates, horticultural growth media, thermal insulation applications and absorbents for spill control and liquid waste containment. The untreated commercial concentrates are used as intumescent fillers in plaster board, gaskets and paints. Several chemically modified vermiculite products include clay-sized dispersions and granules for treating flue gas. South Africa was the only major foreign source of vermiculite used in the United States. It exported about 40 kt (44,000 st) to the United States last year. In 1992, Palabora Mining Co. began processing vermiculite in a new beneficiation mill at Phalabowra. It produced about 164 kt (181,000 st). Minor sources of foreign vermiculite concentrates consumed in the United States included about 140 kt (154,000 st) from China. Brazil also exports some concentrate to the United States.

Jan 1, 1993

By H. A. Doerner

For the past three or four years attention has been attracted to the deposits of lead vanadate in the Goodsprings , Nevada , district . Some ore running as high as 9 per cent 205 has been produced , but most of it runs from 0.5 to 3 per cent . Only a little ore , and that of the richer sort , has been shipped , since the low- grade ore will not stend the cost of shipment and no concentration mill has been available . Preliminary experiments indicate that chemical treatment of the low- grade ore without concentration is not feasible . Its treatment therefore involves two distinct problems ; first , mechanical concentration ; and second , a smelting or chemical treatment to obtain the lead and vanadium in marketable form . Upon this basis the work has been conducted . The writer wishes to acknowledge the excellent work done by J. T. Norton and Virgil Miller on table concentration and by J. E. Conley , who suggested and did preliminary work on the direct smelting method . Many helpful suggestions were received from Dr. S. C. Lind and John Gross of the Bureau of Mines . The ores were furnished by Mr. Frank Williams and Mr. James Ewing .

Jan 1, 1923

By S. V. Burr

"IntroductionOne of the more puzzling geological enigmas, in the writer's opinion, is how rock can move sideways with respect to other rock. In the writer's study of regional northwest-southeast folding in North America (Burr, 1980), he may have found the answer to horizontal offset.Horizontal OffsetSideways movement or horizontal offset does not mean that the movement was, or is, horizontal. As indicated below, the actual movement may be at a high angle from the horizontal. However, it is the horizontal VECTOR, or offset, which is measured on surface by geologists. Vertical movements (thrust, normal, reverse) can be understood, as they involve blocks of rock , generally separated on four to six sides, which have been pushed up or subsided. Vertical faulting across dipping strata can produce APPARENT horizontal offsets. However, this thesis deals only with ACTUAL offsets.The ProblemFigure 1 is a plan view of a simple hypothetical horizontal offset. Three vertical dykes are intersected by a fault lineament. Two dykes exhibit no movement; the middle dyke has been offset a distance (a). Vertical faulting would have produced no horizontal offset. How can a horizontal distance (a) disappear or appear? Rock expands or contracts in infinitesimal amounts.SolutionThe map (Burr, 1980) shows the writer's interpretation of regional northwest-trending folds in Ontario. The writer made two observations about horizontal offsets during his thirty year study of these folds:1) All major horizontal fault lineaments strike at a high angle to the northwest fold axes. Many of the northwest-trending lineaments are fault s, but their movement is essentially vertical.2) Close to many of the known horizontal offsets (and several lineaments), there are areas where plunge reversals are so frequent and close together it is impossible to draw in all the fold axes at a scale of 1 inch = 4 miles, and, in the highly faulted Espanola area southwest of Sudbury, Ontario, all the indicated folds cannot be easily separated at a scale of 1 inch = 1 mile. The writer has observed folds less than 30 feet apart next to the strong Puskitamica-Chibougamau fault in northern Quebec."

Jan 1, 1982

By R. H. Fett

T HE APPROACH to maintenance must always be ?completely positive: there must be no question of putting off difficult problems until it is more convenient to tackle them. By this it is meant that a piece of machinery or equipment which, by experience, is known to be due for a check should not, merely because it appears to be operating satisfactorily, be left until it reaches a critical .condition and breaks down. The mentality of the Maintenance Manager must be completely orderly and methodical and he should, in fact, possess a ledger-book mind, having a debit and credit outlook. The debit side would be that applying to time out of service, cost in wages, material, personnel involved, etc., and the credit side that relating to continuous operational time of the locomotive and therefore to the ultimate benefit of the mine and the personnel who work there. The Maintenance Manager is not concerned with design problems, and although he and the personnel under his jurisdiction are not engaged in productive work, he and his staff do, nevertheless, add greatly to or detract from the overall efficiency of the organization. Provided the machinery placed in his care is good to start with, he must take the best steps he possibly can to keep it running. However, he may, on occasion, be forced to improvise and this is where the ingenuity of a clever man rises to the occasion.

Jan 1, 1956

By Xiao Hong, Zhang Wenqiang, Gao Bing

The characteristics of top charging coke (coke 1) and stamp charging coke (coke2) were investigated. The weight loss ratios of two kinds of cokes with and without alkalis were measured after reacting with CO under the temperature of 2 900, 1000, 1100 and 1200 °C respectively. The microstructures of original cokes were observed by SEM. The experiment results show that, with no addition of alkali, the weight loss ratios of coke 1 and coke 2 were nearly the same under the temperature of 900 and 1000 °C. While the weight loss ratio of coke 2 was much larger than coke 1 under the temperature of 1200 °C. With alkali-rich, the weight loss ratio of the two cokes was almost the same at 1100–1200 °C.

Mar 1, 2017

By J. K. A. McLEOD

Address by the President of the Institute (Mr J K A McLeod) in presenting the Institute Medal to Howard Knox Warner, C.B.E. Address by Howard Knox Warner after accepting the award.

Jan 1, 1978

By D. J. McLaws

"Recent innovations in metal smelting technology utilize continuous oxygen-enriched smelting and converting processes which are capable of producing off-gases containing up to 60% SO2 or more. Other SO2 recovery processes, involving solvent absorption and steam or vacuum regeneration, can produce off-gases with SO2 concentrations nearing 100%.Processing of these high-concentration SO2 off-gases in conventional sulfuric acid plants can cause excessively high catalyst bed temperatures and poor SO2 conversion. In order to avoid these problems, a conventional acid plant design must dilute these high SO2 process gasses with dilution air in order to provide the required oxygen to effectively convert the SO2 and provide a heat sink (via the inert N2) such that the exothermic reaction, SO2 + ½ O2 ???SO3, does not exceed the temperature limit of the catalyst or the converter vessel.MECS, Inc. (MECS) has proven that a high SO2 feed gas design can be a viable option which can increase energy recovery, reduce energy consumption and potentially reduce capital costs."

Jan 1, 2014

By S. W. McCandless

Since the mid 1970's, the science of remote sensing has invented and demonstrated sensors that hold unique promise for users that operate in the marine environment. Earlier, visible and infrared sensors provided images and temperature maps of surface conditions, but the 1970's introduced active (radars) and passive (radiometers) microwave sensors capable of penetrating clouds and operating day or night over the world's oceans. Space-based observation satellites permit these systems to span the globe many times each day, providing a view of the world's oceans and Arctic areas consistent with daily and, sometimes, hourly changes in the marine environment. Experimental satellites launched by NASA proved that such systems had great scientific merit, but, even more importantly, they could produce information valuable to marine transportation, fishing, and resource exploration and extraction. This latter subject includes the off-shore search and production of petroleum and natural gas resources and ocean mining as well. A few early satellites, such as GEOS-3, Nimbus-7, and most notably Seasat established that global wind fields, all weather sea surface temperature, ocean topography and sea state, and fine scale images of wave patterns, surfactants,

Jan 1, 1986

By K. Fukushima, K. Baba, H. Kurokawa, M. Yamagiwa

"The Toyo smelter has expanded its anode production capacity from 126,500 to 239,000 t/year by introducing technical oxygen into blast air for flash and converter furnaces and improving smelting facilities. Significant efforts were made in the expansion not to increase the number of workers, which mean development of some automation systems for the copper converters and anode casting wheel. The efforts have resulted in the above-mentioned increase in productivity and a saving of production cost as well as a decrease in the number of workers for the anode casting operation.IntroductionThe Toyo smelter has been performing a highly stable and pollution free operation since its commencement in 1971 (1). Its distinctive features are the on-line control by process computer (2) and the high productivity without trouble. But owing to the so-called oil crisis in 1979, we were faced with a sharp increase in production cost. To decrease the production cost, some measures for saving of energy were planned and carried out, such as conversion from oil to coal in a flash furnace (3), the heat recovery from converter slag and the introduction of technical oxygen in blast air with the intention of energy saving as much as possible.The first increase in production capacity and some savings of production cost were attained in 1982 by the introduction of technical oxygen in blast air for the flash furnace without major modification of the furnace as shown in Table I. The capacity of an oxygen plant is 7,800 Nm3/H as 90% O2 . Part of oxygen from the plant is also supplied to tuyeres of copper converters through an oxygen holding tank with a volume of 830 m3 at 7 kg/cm2-G."

Jan 1, 1989

By Charles Waidner

IN response to many urgent requests for a concrete realization of a series of standard temperatures that would be available to any one anywhere for the standardization of pyrometers and the reproduction of the standard scale of temperature for use in laboratories and industrial works, the Bureau, in 1916, made arrangements with several manufacturers to prepare a series of- pure metals that could best serve this purpose. After the necessary preliminary work of chemical analysis, as a check on the purity, together with exact determinations of melting or freezing points, the Bureau began, in 1917, the issuing of melting -point standards of tin, zinc, aluminum, and copper. At the outset, it was decided to secure metals of the highest purity and of American manufacture, and this was accomplished in a more satisfactory manner than anticipated. In the preparation of these temperature standards, the Bureau has had the hearty cooperation of several American companies, which have succeeded in producing metals highly satisfactory for the purpose and of as high a state of purity as could have been obtained anywhere. Each company that undertook the responsibility of furnishing a metal for this series of standards exercised most painstaking care to produce the best possible product as to purity and uniformity. A representative of the Bureau witnessed the actual preparation of each metal. The 300 and 400-lb. (136 and 181-kg.) samples making up the first series were all used up, with the exception of the aluminum, early in 1919. The Bureau has taken steps to replenish its stocks of metals serving as pyrometric standards and to the list has been added lead. The copper and lead are being ordered this time in 1-ton lots and the zinc and tin in 300-lb. (136 kg.) lots as before. The wide dissemination of these samples will be appreciated when it is noted that the metals are distributed by the Bureau inn quantities of 50 cu. cm. each, at $2 a sample and accompanied by a certificate which gives the melting point as determined by samples from the same lot. The manufacture and detailed description of chemical analyses, physical measurements, and precautions in use of these pyrometric standards, are described in detail in the Bureau Circulcar No., 66.

Jan 8, 1919

By Harold M. Smith

Among the more important raw materials now utilized for the commercial production of synthetic organic chemicals is natural 'gas. Natural gas has been used as a fuel and source of energy almost from its discovery, but its potentialities as a chemical raw material were not realized until recently. Research in the use of natural gas for Chemical synthesis received great impetus from the discovery by Brooks and Humphrey4/ in 1918 of alcohols in the diluted ?acid oil? obtained by sulfuric acid treatment of cracked petroleum distillates. Experimental data soon showed that hydrocarbons from natural gas could be converted to these same products. Laboratory methods for chlorination of natural-gas hydrocarbons, particularly of methane for the production of methyl chloride, methylene chloride, carbon tetrachloride, and chleroform were known before that time but were not developed commercially. Methods for obtaining alcohol by oxidation of hydrocarbons derived from natural gas also were known before 1918 but had not received commercial consideration. Since 1918, and particularly during the past 15 years, the work of chemists and chemical manufacturers throughout the world has resulted in an accumulation of data regarding the reactivity of natural-gas hydrocarbons, and related hydrocarbons found in refinery gases or made synthetically. These data have been used to develop methods for converting hydrocarbons into chemical products and thus form the basis for a large and growing industry.

Jan 1, 1947

By Harold Hopkins

THE Wright-Hargreaves mine is one of a group of seven mines long active in the Kirkland Lake district, Ontario. Detailed geological reports and maps covering the area have been published by the Ontario Department of Mines (1,3)t. Though all these mines work several productive veins there is one vein which is common to all and is known as the North Vein of the camp?not that it is the most northerly vein mined, but it is the more northerly of the two major veins of the camp. At the Wright-Hargreaves mine there are in all ten important producing veins, and most of them have a N.60°-65°E. strike and in general a steep southerly dip. It is a common belief that most of these veins lie along faults but it will be shown that whilst this is true of some of them it is not true of all, and also that a vein may lie in a fault along part of its course and elsewhere fill a fracture in line with the fault, this being a consequence of rotational movements that took place during faulting. The paper describes the history of faulting at this mine in particular, makes observations on the principal pre-ore fault, and describes the method used in solving the movements on the post-ore faults. Other details of geology are not discussed except to mention here that our main veins lie almost entirely in the syenite porphyry stock except on lower levels close to the east boundary of the property, where the North vein leaves the porphyry to enter the greywacke.

Jan 1, 1940

By P. Dhar, H. R. Kota, M. Thornhill

Precipitated calcium carbonate is used as a filler and coating material in the manufacturing of paper because of its high brightness and light scattering characteristics. However, beneficiated calcite has similar potential, given the fact that the industrial specifications are already achieved. For paper industries, the requirement is that the desired product should be pure and have a brightness of 93 to 95 percent. A very-high-grade calcite deposit of around 92 percent is located in the north of Norway, which is used as the raw material for ground calcium carbonate (GCC) feed for the paper industries. There is a substantial amount of calcite resource, which has pyrite and pyrrhotite as major impurities. These sulfides, even when present in minor concentrations, impart color to the end product (paper). Removing these minerals is estimated to increase utilization of the deposit by 10  percent, which represents several million tonnes of calcite marble. Due to the requirement for environmentally friendly reagents and chemicals by the mineral industry, fatty di-amines are being tested for pyrite and pyrrhotite flotation. The interaction mechanism of diamine with the main components of the ore were studied and optimum conditions for removal of sulfide impurities are outlined.

By B. Wilshire, W. J. Evans

W. J. Evans and 8. Wilshire SEVERAL recent investigations1-6 have shown that the strain, c, during transient and steady-state creep is well-represented by the expression: € = e0 + et(l - e-mt) + Esl [l] where Eo is the instantaneous strain on loading, ET the total transient strain, C, the steady creep rate! and m a constant relating to the rate of exhaustion of transient creep. However, it has been noted6 that deviations from this equation occur over the first 10 to 15 pct of the transient stage, when the creep rate, (. decreases more rapidly than is predicted by this equation. This rapid decrease has been attributed to a large change in work-hardening coefficient. It 1s widely accepted that steady-state creep results from a balance between the rate of strain hardcning h and the rate of recovery r (=-s(st) as: dE/dt = Es = r/h [2] Comparison of values obtained for h at the end of the initial extension and during steady creep suggests that h increases several fold during the transient stage. which has the effect of reducing the creep rate proportionally.7 To examine the dependence, on r and h, of the deformation behavior during transient and steady-state creep. a series of constant-stress creep tests was carried out at 413°C at 6000 psi using 70-30 a brass. Prelinlinary investigation showed that. with this material. the transient stage constituted a significant portion of the total creep life (-0.4tf. where tf is the time to fracture). The alloy. obtained from Metals Research Limited. was made from high-purity copper, 99.999 pct. and zinc. 99.99 pct. Heat treatment at 675°C for 4 1/2 gave a uniform grain size of 5 mm-1. Details of specimen preparation and creep testing procedures have been given previously.6 Values of h (?s/?E) were determined by measuring the instantaneous strain. ?E. which occurred on increasing the stress during creep by a small amount. ?s. Similarly. v (= -?s/ ?t) was derived from the incubation period. At, after a small decrease in stress.' Several values of v and h were obtained throughout duplicate creep tests. using different stress increments in the range 300 to 800 psi. The accuracy with which Eq. [I] represents the present creep curves was established by determining the best value of the constants Es, Et, m , and 6, using a digital computer program based essentially on the graphical solution for this equation devised by Conway and Mullikan.9 About 40 strain/time readings were taken during transient and steady-state creep. Over most of the creep curve, the average difference between the measured reading and the calculated strain at the appropriate time was less than 0.0001. However.

Jan 1, 1969

By Mohsen Hashemzadehfini

Nowadays heap leaching has become established as a mineral processing technology for treatment of some low grade minerals such as copper, gold, and zinc, etc. Heap height, particle size, leach reagent consumption, and metal recovery are four important metallurgical parameters in a hydrometallurgical process like heap leaching. This paper investigated the effects of heap height and particle size on copper recovery as well as acid consumption. Three heap heights of 2, 4 and 6 meters and two particle size fractions of less than 25.4 mm and 50.8 mm were selected as variables in the experiments. The research results showed the inverse relation between heap height and copper recovery as well as acid consumption. Under given conditions, the copper recoveries of minus 25.4 mm ore are 78.63%, 66.27% and 52.88% higher than that of minus 50.8 mm samples for the heap heights of 2, 4, and 6 m, respectively. Both copper recovery and acid consumption increase with decreasing particle size. Keywords: heap leaching, heap height, particle size, acid consumption

Sep 1, 2012