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By G. H. Lair, B. J. Langford, S. H. Rockwood

Volumetric reservoir analysis is dependent upon a firm relationship between porosity, connate water, and net pay. Capillary presswe data on core samples interrelate these three factors. It is shown that other reservoir problems may be resolved: (I) whether water production is indigenous or extraneous to the oil producing interval, (2) an oil-water contact is being approached, and (3) whether the oil-water contact is remotely situated. INTRODUCTION Volumetric analysis of carbonate reservoirs challenges the ingenuity of the reservoir engineer due to an absence of data on the minimum oil-bearing and oil-producing pores of a given reservoir rock. Many studies with this as the ultimate objective are available on the physical characteristics and fluid-flow behaviors of the carbonate reservoir. Some of these publications are: Hassler, Brunner and Deahl's1 study of the role of capillarity in oil production; Jan Law's' and A. C. Bulnes3 statistical treatment of core analysis data; Chalkley's method4,5 or estimating specific surface areas and porosity; Walter Rose's9 report on porosity, reserves, and recovery; Archie's78 tex-tural classification of carbonate rocks; Stewart and Spurlock's9 large core analysis; Purcell'sl0 mercury injection method in studying capillary pressure phenomena; Stewart, Craig, and Morse's" model multiple-phase flow test in investigating the relative permeability effect; and Fatt's12 illumi-nating network model of porous me-dia. The present study shows that the static reservoir parameters of porosity, connate water, and net productive thickness may be interrelated by utilizing a statistical arrangement of mercury capillary pressure data in addition to routine core analysis. This report summarizes the techniques that are followed to obtain these relations which are applicable to carbonate and sandstone reservoirs that do not contain clays. Capillary pressure statistical studies may be extended to include clay-bearing rocks by utilizing water capillary pressure data. POROSITY It is necessary that the laboratory determine the porosity value that includes the pores that are filled with hydrocarbons and water in the reservoir. This is the reservoir's total porosity. When true total porosity values are not available, correlations between porosity and capillary pressure characteristics lose their significance since they cannot be related through oil-base mud core data to the porosity and connate water values found in reservoirs. Methods used to obtain reliable porosity data will not be discussed; however, care should be exercised in selecting samples for measurement. In homogeneously porous formations, small core plugs sampled frequently will furnish adequate information. Where heterogeneity, particularly vugginess, is present, large-core porosity data may be required; in such reservoirs a suite of capillary pressure samples may be selected from small plugs. CAPILLARY PRESSURE Capillary pressure data provide a method for relating two carbonate reservoir parameters, porosity and connate water saturation, which in turn permit delineation of productive rock types necessary for selecting the third parameter, productive thickness. Specific applications of capillary pressure data to petroleum reservoirs were suggested by Archie8 and Pur-cell."' Their work demonstrated that in preferentially water-wet rock, porc

Jan 1, 1958

By W. T. Lankford, Low J. R., Gensamer M.

The problem of sheet metal formability is one which has received a vast amount of attention during recent years. In spite of the great amount of study and experimental work which has been devoted to this problem, many of its fundamental aspects are still not well understood. No generally satisfactory test has been developed which is capable of providing a reasonably adequate evaluation of sheet metal formability, particularly in borderline cases. Anomalies persistently arise in which a lot of supposedly satisfactory material exhibits excessive breakage when formed. This lack of suitable technological tests greatly hinders the design of new parts and the substitution of new materials in parts of existing design, frequently necessitating considerable costly trial and error experimentation on an actual production basis. When, at the beginning of World War 11, it became apparent that mass production methods of forming would bc required in the aircraft industry if the large numbers of military aircraft needed were to be supplied, renewed attention was focussed on the problem of sheet metal formability. It was widely recognized that the formability requirements placed on sheet metals had been steadily increasing in severity through the years, especially as greater and greater emphasis was placed on streamlined designs with the resultant freer application of doubly curved surfaces. The recent advent of several new high strength aluminum alloys of more limited formability than some of the older alloys also served to emphasize the need for new approaches to the problem. It seemed evident that progress in the technology of sheet metal forming would depend to a great extent on the development of more reliable criteria for the evaluation of formability. Although the problem is admittedly very complex, the most logical approach appeared to be through studies of the fundamental material properties of sheet metals, especially under complex stress conditions simulating those prevailing in actual forming operations. Most previous investigations have failed to make full use of existing knowledge of fundamental material properties, and in many instances have attempted correlations with properties which are now recognized as being ambiguous in nature. This investigation was undertaken, therefore, with the aim of developing methods for the study of the flow and fracture of sheet meta1s under combined stresses, and of making use of such methods as might be developed in

Jan 1, 1947

By Andrew J. Hyett

The ISRM commission on testing methods has recently presented Suggested Methods for rock stress determination (Kim & Franklin, 1987). This proposes that even if the magnitude of in situ stress is not sufficient to cause significant ground problems, the optimum shape, orientation, and layout of underground structures can be significantly affected by it. In the design of underground excavations, the engineer often requires a knowledge of the average in situ stress tensor in the rock mass. However, attempts to measure a stress state applicable to design have proved frustrating, and a high degree of uncertainty is introduced by the variability in results. In the belief that deduced fluctuations are random in nature, many separate measurements are often made, so that a more reliable stress tensor average, and some indication of the associated variance (see Dyke et al., 1986) can be calculated. Unfortunately, this approach is limited by economic considerations and, as with any sampling procedure, it is imperative to understand the sources of measured variability, in order to design an optimum measurement programme. Cundall(1987) itemised the main causes of stress variability as a. Instrument and measurement errors, and b. Natural fluctuations of stress from point to point, induced by the action of a boundary stress on the internal rock structure. At least four categories exist: i. inhomogeneous rock, bedding, intrusions etc.; ii. differential contraction, creep, or changes in rock properties with time; iii. proximity to faults or discontinuities; iv. cycles of tectonic activity that cause movement on joints. The latter was successfully investigated using the distinct element programme UDEC. In this paper, the contribution of items (iii) and (iv) (i.e. the items related to discontinuities) to the total stress variability will be discussed, for the kind of rock mass shown in Figure 1. Although many authors have concluded that rock joints have an influence on the stress in their vicinity, a more analytical approach is required if the stress distribution associated with different jointed rock masses is to be (i) compared, and (ii) related to routinely measured joint parameters. If this can be achieved then, prior to any attempt to measure stress in a jointed rock mass, a consideration of joint geometry, joint deformability, and the geological kinematics of joints (e.g. the magnitude and direction of previous movements), can place valuable `common sense' constraints on the expected stress system for minimal extra cost.

Jan 1, 1989

By Low J. R., Gensamer M., W. T. Lankford

The problem of sheet metal formability is one which has received a vast amount of attention during recent years. In spite of the great amount of study and experimental work which has been devoted to this problem, many of its fundamental aspects are still not well understood. No generally satisfactory test has been developed which is capable of providing a reasonably adequate evaluation of sheet metal formability, particularly in borderline cases. Anomalies persistently arise in which a lot of supposedly satisfactory material exhibits excessive breakage when formed. This lack of suitable technological tests greatly hinders the design of new parts and the substitution of new materials in parts of existing design, frequently necessitating considerable costly trial and error experimentation on an actual production basis. When, at the beginning of World War 11, it became apparent that mass production methods of forming would bc required in the aircraft industry if the large numbers of military aircraft needed were to be supplied, renewed attention was focussed on the problem of sheet metal formability. It was widely recognized that the formability requirements placed on sheet metals had been steadily increasing in severity through the years, especially as greater and greater emphasis was placed on streamlined designs with the resultant freer application of doubly curved surfaces. The recent advent of several new high strength aluminum alloys of more limited formability than some of the older alloys also served to emphasize the need for new approaches to the problem. It seemed evident that progress in the technology of sheet metal forming would depend to a great extent on the development of more reliable criteria for the evaluation of formability. Although the problem is admittedly very complex, the most logical approach appeared to be through studies of the fundamental material properties of sheet metals, especially under complex stress conditions simulating those prevailing in actual forming operations. Most previous investigations have failed to make full use of existing knowledge of fundamental material properties, and in many instances have attempted correlations with properties which are now recognized as being ambiguous in nature. This investigation was undertaken, therefore, with the aim of developing methods for the study of the flow and fracture of sheet meta1s under combined stresses, and of making use of such methods as might be developed in

Jan 1, 1947

By E. E. Maust

The literature on the activation of sphalerite for flotation by short¬chain xanthates leaves unanswered the question of whether a compact surface film of activator sulfide is necessary or merely sufficient for high flotation recoveries. Studies by Guarnaschelli and Plaksin indicate that xanthate adsorption and flotation of sphalerite are increased with increasing hole/ electron ratio. These results, and the known acceptorlike behavior of many heavy-metal impurities in zinc sulfide, suggest that activation may result from a traditional semiconductor doping effect at the surface. Using the theory of chemisorption states on ionic crystals as developed by Levine and Mark, the Bureau of Mines has carried out A calculation to estimate the surface-state energies of various metals when they are substituted at zinc sites on (110) sphalerite surfaces. Based on a simple Madelung-Born treatment of ionic solids, the calculation indicates that many of the metals known to activate sphalerite for subsequent flotation have lower surface-state energies than nonactivators. The results of these calculations are discussed from the standpoint of consistency with the proposed activation mechanism and observed flotation results. The satisfactory agreement obtained is taken to be support for the proposed mechanism, and further elaboration of a surface-doping model is attempted.

Jan 1, 1976

By P. T. Bloomer

Introduction Mining of the orebody of the Sullivan mine, which is owned and operated by the Consolidated Mining & Smelting Company of Canada, Limited, has reached a point where pillar extraction is rapidly becoming a major part of the operation. Very few of the larger pillars have been completely extracted; consequently, this paper contains much that is theory and expectation. Due to early mining methods and the physical characteristics of the Sullivan deposit, similar conditions may not exist in other older mines facing the problems of pillar extraction, but it is thought that the methods employed and those contemplated may be of general interest. History The Sullivan orebody, which is at Kimberley in the Fort Steele mining division of the East Kootenay district of British Columbia, was discovered in May, 1892, by Messrs. Sullivan, Smith, Cleaver, and Burchett. After passing through the hands of several owners the property was optioned in 1909, and purchased in 1910, by The Consolidated Mining and Smelting Company of Canada, Limited. Early mining was highly selective, the objective being a clean, high-grade silver-lead ore. By 1923 the difficulties of milling the very complex ore had been overcome and the first unit of a concentrator was completed with a capacity of 2,500 tons daily. Capacity was increased by stages to the present rate of 8,500 tons per day. Concentrates are shipped over the Canadian Pacific railway ? to the Company smelter at Tadanac, British Columbia, for final treatment. Approximately 45,000,000 tons of ore has been mined to date.

Jan 1, 1948

By G G. Suffel

T HESE remarks on the occurrence of strata-bound massive sulphide deposits are submitted be-cause the writer recently visited the principal Cyprus deposits (in January, 1965) and has also a back-ground of many years spent largely in detailed observation and map-ping of the Horne and Amulet ore-bodies, now largely inaccessible. They are particularly related to the Symposium papers (September Bulletin) by Hutchinson and by Roscoe. Some comments are offered on the cupriferous pyrite deposits of Cyprus. As the writer is currently reviewing the published literature on the related deposits in Turkey, a brief account of some characteristic Anatolian sulphide occurrences is given. The discussion is closed with some thoughts on the relationship between these Mediterranean sulphide deposits and those of northwestern Quebec and the Superior province in general. The geology of Cyprus, as it relates to the sulphide deposits, is well summarized by Hutchinson (1965). After visiting Mavrovouni, Skouriotissa and Limni and after much thought on the possible ge-nesis of these ores, it seems quite logical to me that he is right. They are indeed closely related to late-stage submarine volcanism.

Jan 1, 1965

By Kyeong Woo Chung, Rina Kim, Ho‑Seok Jeon, Yeongjin Ahn, Byunghun Go, Min‑seuk Kim, Hong‑In Kim, Sujeong Lee, Yuik Eom

The study focused on the recovery of vanadium from a Korean vanadium-bearing titaniferous magnetite (VTM) ore, examining the behaviors of magnetic separation and Na2CO3 roasting-water leaching. Two concentrates were prepared using single-stage dry magnetic separation and three-step wet magnetic separation, resulting in V2O5 grades of 0.8% and 1.0% and major gangue mineral SiO2 contents of 6.5% and 1.7%, respectively. These concentrates were subsequently roasted at 1050 °C with the addition of Na2CO3 and then water-leached at 25 °C. Various stoichiometric ratios of V2O5 to Na2CO3 were tested, ranging from 1:1 to 1:40 of the theoretically required amount. As the amount of Na2CO3 increased, the vanadium leaching efficiency showed fluctuations between 4 and 35% for ratios of 1:1 to 1:10, while it linearly increased from 4 to 82% for ratios of 1:10 to 1:40 in the leaching of the low-grade concentrate. In contrast, the leaching efficiency increased from 47 to 74% for ratios of 1:1 to 1:8 and then sharply rose to 84% at a ratio of 1:10 in the leaching of the high-grade concentrate. Subsequently, it reached a plateau of 92 to 94% for ratios of 1:20 to 1:40. The difference in leaching efficiency was primarily due to the reaction of gangue minerals with Na2CO3, which hindered vanadium leaching from the VTM concentrates. This hindrance was notably more pronounced in the low-grade concentrate with the lower salt ratio, as the gangue minerals exhibited a preference for consuming Na2CO3 over vanadium. The mineral formation was analyzed in detail using XRD and MLA to shed light on the mechanism of different vanadium leaching behavior depending on the concentrate grade and vanadium to salt ratio. Based on the results of this study, it is evident that applying a proper magnetic separation procedure is significant to achieving satisfactory vanadium recovery with less salt amount by removing gangue minerals ahead.

Mar 15, 2024

By F. E. Harris

IT has been said that carbon is "ubiquitous" with reference to iron alloys. Certainly at temperatures where carbon and iron form the solid solution, austenite, it may be readily added to, or removed from, steel surfaces. Differences in concentration potential are the sole requirements for carbon flow. To measure the rate of carbon flow, a proportionality factor, D, is arbitrarily expressed in units of (length)2 X (time)-1. If the term used for carbon concentration is weight pct C, as is customary, then a factor must be found, changing this term to one of weight per unit volume when the diffusion coefficient, D, is used in flow formulae. The determination of D values for carbon is complicated since D varies with the concentration itself. The Matano method has often been employed for systems involving a variant D. This method expreses an evaluation of unsteady flow whereby .0 is given a relationship with the numerical value of C-X slopes. The author contends that this solution is incorrect, except when D is invariant. The primary purpose of this paper is to support this contention. Here diffusion is controlled under two conditions of flow. The first part deals with the steady state; the second part considers unsteady flow under definite restrictions. Beginning with the fundamental concept, the development is continued until equations for C-X curves are obtained. The solution is then subjected to experimental data. It is realized that a great amount of reliable data is required for a rigorous proof. No such research is claimed. Instead an attempt is made to set forth the physical significance of the diffusion mechanism, and particularly to express the factors which influence the flow of carbon in austenite. Of equal significance is the implication that gaseous media may be employed with reasonable accuracy in making these determinations. THE STEADY STATE DIFFUSION OF CARBON IN AUSTENITE The fundamental experiment defining diffusion in solid metals may be readily performed for carbon in gamma iron.1 For this experiment a thin plate of medium carbon steel is chosen. The surfaces of this plate may be taken as two parallel planes which may be considered infinite for points well in the center of the planes. These two planes are held at different concentrations of carbon at a constant temperature. This temperature, 1700°F for example, is one where the single phase, carbon in solution with gamma iron, exists. When these conditions are held for a sufficient time the concentration of carbon of the different points of the solid settles down towards its steady state value. At points well removed from the ends, the concentration will remain the same along planes parallel to the surfaces of the plate.

Jan 1, 1947

By R. D. Pehke, J. F. Elliott

The solubility of nitrogen in liquid pure iron has been measured as a function of pressure and temperature. Sieverts' Law is obeyed at all pressures up to 1 atm and the temperature coefficient of solubility is 8 x 106 %/°C. The solubility of nitrogen in liquid iron alloys has been studied by the Sieverts' method and by the sampling method. The solubility is decreased by Al, C, Co Cu, Ni, 0. Si atzd Sn, and it is increased by Cr, Cb, Mn, Mo, Ta, W, and V. Interaction coefficients eN, for the effect of these elements on nitrogen dissolved in liquid iron, are reported. 1 HE effect of nitrogen upon the properties of steel may be desirable or not, depending upon the composition, processing treatment, and the use of the product. To understand the behavior of nitrogen in the various steelmaking processes, it is necessary to have reliable fundamental data pertaining to the solubilities, rates of solution, and chemical reactions of nitrogen in steel, particularly in the liquid state. In an effort to extend our knowledge in these areas, an investigation of the thermodynamics and kinetics of the solubility of nitrogen in liquid iron alloys was undertaken. The thermodynamic aspects of the study are presented in this paper. The solubility of nitrogen in liquid pure iron has received the attention of several investigators whose results are summarized in Table I. Reasonable agreement among the more recent researches1-l8 is found for the solubility of approximately 0.044 wt pct at 1600°C and 1-atm pressure of N,, for the temperature coefficient of solubility being small but positive, and for adherence to Sieverts' law for pressures up to 1 atm. The solubility of nitrogen in a number of binary liquid iron alloys has been studied: Fe-A1,3 Fe-As,16 Fe-C,3, 71 18, 19, 20 Fe-Cr ,5,7, 10, 11, 15 21 Fe-Co,'4, '6 Fe-Cu,'6 Fe-Mn,10, 11, 18 Fe-Mo,13, 16 Fe-Ni,10, 11, 13, 15, 16 Fe-O,16, 17, l9 Fe-p,7 Fe-S,l6 Fe-Sb,16 Fe-Se,lg Fe-Si,4) 97 '77 187 19>2° Fe-Sn,16 and Fe-v.51 '3 A few ternary systems have been studied, most of which were reviewed by ~angenberg" who applied the methods suggested by WagnerPz3 Chipman,24 Darken and G~rry, and Morris and Buehl26 for predicting solubilities in multicomponent alloys. Langenberg22 and Humbert and Elliott15 compared the solubilities computed from simple binary alloy systems with experimental measurements of nitrogen solubilities in liquid iron containing two or more alloying elements. The interaction coefficients for nitrogen in

Jan 1, 1961

By John H. Bassarear

How best to grind? This article compares conventional crushing and grinding circuits to semiautogenous circuits, reviews recent installations of each circuit, and describes seven methods of using autogenous or semiautogenous techniques. In addition, steel and power consumption data are reported and benefits of a dedicated digital computer are discussed. Size reduction is the most expensive operation in most mills. Crushing and grinding are usually the greatest part of capital costs. They often make up 60-70% of total mill operating costs. Picking the proper crushing and grinding method must, therefore, be done with great care, so the best circuit is chosen. In the past 10 years, there has been a strong trend toward using autogenous or semiautogenous grinding in mills throughout the world. Autogenous grinding is favored when the ore is quite competent and a fine grind is needed. Semiautogenous grinding is applied when fine crushing could cause severe problems or when ore varies in hardness or competency. The taconite iron ores of northern Minnesota fit the description for an autogenously ground ore and many are successfully ground that way. Most im¬pressive are the nine lines of 11 x 4.9 m (36 x 16 ft) mills powered by 9 MW (12,000 hp) motors at Hibbing Taconite. Porphyry copper and molybdenum ores fit the description for semiautogenous grinding. Recent installations include Highmont in British Columbia, Canada, and Quintana in New Mexico. Sampling Many mills have been built based on inadequate sampling data or insufficient tests. With the cost of many mills exceeding several hundred million dollars, it is mandatory that geologists, mining engineers, and metallurgists work together to prepare representative testing samples. Simple, repeatable work index tests are usually sufficient for rod and ball mill tests. However, pilot plant tests on 50-100 t (55-110 tons) of ore are frequently necessary for autogenous or semiautogenous mills. Preparation and selection of the test sample is of utmost importance. Procedures for autogenous and semiautogenous mill pilot plant tests are relatively simple for those experienced in running them. Reliable and repeatable results can be obtained if simple, fundamental procedures are followed. The accompanying figure shows a typical conventional crushing-grinding circuit with three stages of crushing followed by ball mills or a rod mill-ball mill combination. This flowsheet is typical of many mills that have been built throughout the world. Also shown is a typical semiautogenous (SAG) circuit with feed coming directly from a primary crusher, and the semiautogenous mill product going to the separation process. Many similar semiautogenous circuits are built today because they are simple and flexible, lend themselves readily to high tonnages, and usually cost less to build and operate. With some ores, it is possible to send mine-run ore directly to the semiautogenous mill, eliminating the need for a primary crusher, as at Benquet's Dizon mill in the Philippines. An autogenous or semiautogenous circuit, as the name implies, uses the ore itself to assist in the grinding process. Generally, for this type of circuit, the ore must be competent so large ore chunks can be used to grind smaller ones. If ore alone is used, then the circuit is autogenous; but if balls are added to supplement the charge, then the circuit is termed semiautogenous. Ore competency is not always a criterion, to break up large pieces and wash away cementing material. Autogenous and semiautogenous mills have been very successful on relatively soft uranium ores where the values are frequently found in the material that cements together the sandstone grains. Autogenous Circuits When an ore is hard and competent, it is always possible it might make good "pebbles" that could be used for fine grinding media. Seven methods have been tried using combinations of autoge-

Jan 6, 1982

By Ram Song, Yohei Harada, Shinji Kumai, Kazuho Otsuka

"Recently, vertical-type high-speed twin-roll casting (HSTRC) has been developed. The HSTRC shows extremely high cooling rates over 1,000 K/s even at the mid-thickness area. The fabricated strip has many metallurgical characteristics; super-saturation of alloying elements, fine solidified structure, and homogeneous distribution of fine constituent particles. In Al-Mn based alloys, the Mn alloying element can be supersaturated in the a-Al matrix and also form Mn-containing constituent particles during solidification. The Mn supersaturation and the distribution of primary/secondary particles in cast products affect the metallurgical behavior in the down-stream processing and can improve mechanical properties of the final products. In this study, Al-Mn based alloy strips were fabricated by HSTRC with various Mn contents. The solidified microstructure, constituent particles and its distribution, and Mn solubility were investigated in the as-cast condition. Due to the high cooling rate of HSTRC, fine constituent particles were homogeneously distributed, and coarse intermetallics were not observed. Mn solid solubility was estimated by electrical conductivity. The estimated Mn solubility was equivalent between strip surface and mid-thickness area.INTRODUCTION Al-Mn based alloys, as non-heat treatable wrought aluminum alloys, are widely used in packaging and heat exchanger for automobile industry. Besides Mn, Al-Mn based alloys often contain Fe and/or Si as alloying elements or natural impurities. During solidification, Mn can be super-saturated in the Al matrix, and also form Mn-containing constituent particles. Additionally, in the subsequent thermal-mechanical processes such as homogenization, rolling, and intermediate annealing, Mn in solid solution precipitates out of the Al matrix as secondary particles. The size, distribution, type, and the amount of dispersoids including constituent particles affect to texture evolution, recrystallization behavior, and final mechanical properties of wrought Al-Mn based alloys (Huang et al., 2016; Huang & Marthinsen, 2015; Engler et al., 1995; Muggerud et al., 2013). Therefore, controlling the initial level of Mn super-saturation and the distribution of constituent particles are important in the cast Al-Mn based alloys."

Jan 1, 2018

By S Hapugoda, J R. Manuel, M P. Ma, L Lu

Iron ore sinter quality depends heavily on the mineralogy, textures and physical structure of the sinter, which is formed upon solidification of the primary sinter melt. The interactions of the initial sinter melt with its surrounding materials will impact on the properties of the primary sinter melt and consequently the solidified structure of the sinter. By using a high-temperature visualisation system, in situ studies have been conducted on the effects of melt compositions (Al2O3, SiO2 and MgO) on the interfacial phenomena of the sinter melt on a natural iron ore substrate. It was found that the melt composition significantly influenced the wettability between the sinter melt and the iron ore substrate. The interactions between the sinter melt and the natural iron ore substrate were also examined. Such interactions can lead to further changes of sinter melt composition and hence the sinter melt properties that, in turn, further affect the wetting behaviour of the sinter melt.CITATION:Ma, M P, Lu, L, Hapugoda, S and Manuel, J R, 2013. Effects of melt composition on the interactions of sinter melt on a natural iron ore substrate, in Proceedings Iron Ore 2013 , pp 431-440 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By M. V. Rowley, D. D. Warkentin

With high commodity prices, tightening operating budgets and increasing disposal costs, there is an increasing interest in processing municipal waste streams, such as the ash derived from combustion processes. This paper describes laboratory development work for a process to recover metal values from the finer fractions of these wastes. The work was initially aimed at recovery of copper and the removal of lead and other heavy metals from the ash residue, but results showed gold and silver recovery to be an important objective as well. The process uses gravity and flotation as the principal separation steps, with gold recovery occurring mainly in the flotation stage. The particle size range and chemistry of the ash presented numerous challenges to developing a suitable flotation method, but an effective flowsheet was developed by separating the ash into a fine fraction and a separate slime fraction, each with a unique flotation strategy. Specialized conditioning stages and careful reagent selection have resulted in effective gold and silver recovery from a range of ash types and sources. The work has resulted in a patent being issued for a process based on this novel approach to the treatment of combustion wastes.

Jan 1, 2017

By Romulo Camata

O objetivo deste trabalho é estudar as reações de dessiliciação, envolvidas no processo de pré-tratamento de ferro-gusa. A princípio, as misturas utilizadas foram caracterizadas e estudadas através do software de termodinâmica computacional (FactSage). Em seguida, os resultados obtidos através do estudo termodinâmico computacional foram comparados com aqueles obtidos mediante os testes experimentais a 1400 °C. As misturas dessiliciantes tiveram como base fontes de CaO e FeO. Os testes experimentais permitiram identificar que a agitação do sistema, maior quantidade de massa de mistura adicionada e misturas com adição de 20% de fonte de CaO mostraram-se mais eficazes no processo de dessiliciação do ferro-gusa. Com os resultados pode-se afirmar que a termodinâmica computacional mostrou-se eficaz em prever o processo. Além disso, a termodinâmica computacional também contribui, em alguns casos, para a análise de compostos sólidos que podem se formar na escória e limitar as reações de dessiliciação.

Oct 30, 2017

By T. Veneroso

Comminution is the process by which rock or ore is reduced to a size where the liberation of the minerals is maximized without changing the chemical or physical properties of the rock. Comminution accounts for about 50% of all energy that mines use (Klein et al., 2018). Growing demands from stakeholders and shareholders for sustainable development and CO2 reduction will increase the need for energy-efficient comminution. Ores with different mineralogical characteristics, textures, strengths, apparent stiffness, and mass-specific fracture energies need to be processed with a specific, new, and efficient comminution technology to increase the production and profitability of mining companies. The adoption of crusher wear parts built with new materials, such as non-Hadfield manganese steel or synthetic materials or traditional manganese with wear-resistant components, could improve the efficiency of the crushers, reduce downtime, increase production, improve the desired P80 (the aperture through which 80% of the product will pass) product size distribution, and enhance mine safety.

Feb 1, 2023

By David P. Reddick

"Suncor Inc. Oilsands Group mining operation in Northern Alberta, Canada, has been blasting to loosen the oilsands to increase production and decrease maintenance of the bucketwheel excavators for over twenty years. In 1991 an area of the mine was encountered which had a working face of 130 feet rather than the usual 20 to 57. In order to maintain production objectives, the planning and blasting departments of the mine took on the task of blasting as much of the working face as possible. McGinnis Rathole Drilling Company provided the drilling for the project and Mining Services International (MSI) delivered the bulk explosives to the boreholes. It is believed the resultingblasts exceeded several known records in production blasting."

Jan 1, 1992

By Andrzej Warczok

Intensive smelting of copper concentrate in Teniente Converter (CT) leads to the production of high grade matte and highly oxidized slag. Smelting slag is processed in Teniente vascular slag cleaning furnace. The slag composition and forms of copper affect the slag cleaning process and final copper content. Converting of high grade matte in Pierce-Smith converter faces some difficulties in proper slagging of iron oxides. Overblowing in copper making stage allows for slag liquidation but leads to high content of copper oxide in converter slag. Converter slag recycling into CT results in the increase of the participation of oxidic copper. Separate treatment of converter slag and its impact on the forms of copper in CT slag has been analyzed. Thermodynamic properties of a system and kinetic limitations pointed out the negative effect of converter slag recycling on the forms of copper and copper recovery in slag cleaning stage. Experimental results of slag cleaning tests in a crucible scale as well as microscopic examination of laboratory and industrial slag samples supported the above analysis and permitted to formulate recommendations of separate processing of converter slag. Keywords: copper, losses, slag, recycling

Jan 1, 2001

By V. G. Papangelakis, T. Clark, G. Kolliopoulos

Sustainability of the hydrometallurgical industry requires the development of processes for effective water recovery; if process water is recovered and recycled, fresh water intakes will be reduced. Forward osmosis (FO) is an innovative membrane process that promises to recover water from industrial process aqueous streams or seawater with less energy input compared to reverse osmosis (RO) and evaporation; the energy efficiency relies on the spontaneity of the process (no energy input required). The driving force of the process is the osmotic pressure gradient between a dilute feed solution (process water) and a concentrated draw solution. The draw solution is an engineered aqueous solution that contains a highly soluble chemical reagent that is able to osmotically "draw" only water from the dilute stream, through a semi-permeable membrane, leaving behind a small volume of concentrated brine. The draw solute is separated and recovered for reuse, leaving behind water. The main energy requirements of the FO process arise from the separation and the regeneration of the solute chemicals from the diluted draw solution. This work focuses on the evaluation of aqueous carbonated trimethylamine (TMAH:HCO3) as the draw solution and reports recent findings on the separation efficiency of TMA and CO2 from the solution.

Jan 1, 2015

By R. E. Hobart

THE development of the Hauto power plant and the claims made by various engineers that electricity was more economical than steam for power purposes in and about the mines; led the Lehigh Coal and Navigation Co., in 1911, to conduct a test to ascertain the consumption of power used by a large steam hoisting engine. The question being one on which no reliable information could be found, and the opinion of various engineers differing to such an extent, it was decided that a test under actual operating conditions was necessary. This was arranged for at one of the collieries. The engine selected was a 30 by 60-in. (76.2 by 152.4-cm.) piston-valve engine of modern type, and comparatively new. The boiler plant from which the hoist received its power was about 600 ft. (182 m.) from the engine, the latter being fed by a 10-in. (25.4-cm.) steam line insulated with magnesia pipe covering. Two batteries of the boiler plant, aggregating 1200 hp., were cut off and fed into a separate steam line leading direct to the hoist engine. Steam auxiliaries, consisting of feed-water pump and blowers, were fed by the boilers in test, and their consumption charged against the hoist. A barrel weighing device was installed, as it was felt that this would be the most accurate way of determining the consumption of water. The fuel, No. 3 buckwheat, was carefully weighed, and every precaution was taken to make the test accurate in every particular. The test was run for 1 week, or a total of 168 hr. A record was kept of the number of trips hoisted or lowered, and continuous indicator cards were taken. One particular set of cards was taken with the hoist operating balanced, and also with the hoist operating with no counterweight other than the empty cage, the coal in the car being weighed. The speed of the hoist was taken by means, of a graphic recording instrument which registered the number of revolutions every 5 sec. From this record, speed-time curves were plotted.

Jan 2, 1918