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By Graeme Miller

The geotechnical characteristics of the ore are important in understanding the kinetics of a copper heap leach. These characteristics can indicate potential problems and can be used to determine the semi-quantitative changes in field kinetics as compared with column kinetics. The application of this approach allows a more rigorously based determination of ?scale up factors? than has been the case the date. The shrinking core model has been shown to be a poor predictor of leach kinetics based on the crushed ore size distribution. However the model itself is a very useful tool to analyse commercial heap data. Significant geotechnical parameters such as: bulk density / stress characteristic, limit moisture capacity and particle density are used to determine the effect of changes on the diffusion controlled leach rate. By consideration of the geotechnical reaction of the ore mass the leach rate changes are related to changes in these variables. Analysis of commercial heap data has indicated effective diffusion lengths of up to ten times the largest particle size.

Jan 1, 2003

By North R. A

The Queensland Mining Act 1968-1972 has now been in force for almost two years. The Act was completely re-written and has made for easier working, e.g., there is no distinction now between Gold Mining Leases and other Mining Leases. For the first time in the history of Queensland, provision has been made for caveats, so that options etc. can be protected. The chief problem which has arisen so far has been the question of the Government issuing mining leases to the holder of an Authority to Prospect over areas which are included iri its Authority. Litigation has taken place and an Appeal, it is understood, will shortly be heard by the Privy Council. The provisions dealing with labour conditions have been brought up-to-date and generally speaking, they are quite clear as to the responsibility of the Lessee. The Mining on Private Land Act has been repealed and the provisions relating to mining on private land are now a part of the Mining Act itself. Previously, the holder of a- mining freehold did not have to pay royalty on

Jan 1, 1974

By M. W. Hildyard, J. A. L. Napier

The improved design of support systems and stoping strategies when changes in depth, stratigraphy, or mine layouts are considered must rely on the designer's fundamental understanding of the deformation mechanisms adjacent to underground openings so that he can extrapolate and predict expected mining conditions. This paper presents a numerical approach to the modeling of the growth and interaction of mining-induced fractures near the edges of deep tabular excavations in brittle rock. Fractures are represented by displacement-discontinuity elements that are allowed to propagate according to prescribed growth rules. This procedure is justified by the reproduction of several features observed in laboratory simulations of fracturing around openings in blocks of rock subjected to uniaxial and biaxial compression. An attempt is then made to explain some of the attributes of the fracture zone surrounding tabular stopes. Particular questions of interest are the sequence in which fractures form and are mobilized in front of the mining face, the effect of parting planes parallel to the plane of the excavation, and the distribution of stress parallel to the hangingwall and footwall.

Jan 1, 1992

THE Howe Memorial Lecture, in memory of Henry Marion Howe, Past President of the Institute, was authorized in April, 1923, as an annual address to be delivered by invitation under the auspices of the Institute by an individual of recognized and outstanding attainment in the science and practice of iron and steel metallurgy or metallography, chosen by the Board of Directors upon recommendation of the Iron and Steel Division. The following were the Howe lectures and lecturers for the years indicated: 1924 What is Steel? By Albert Sauveur. 1925 Austenite and Austenitic Steels. By John A. Mathews. 1926 Twenty-five Years of Metallography. By William Campbell. 1927 Alloy Steels. By Bradley Stoughton. 1928 Significance of the Simple Steel Analysis. By Henry D. Hibbard. 1929 Studies of Hadfield's Manganese Steel with the High-power Microscope. By John Howe Hall. 1930 The Future of the American Ironand Steel Industry. By Zay Jeffries. 1931 On the Art of Metallography. By Francis F. Lucas. 1932 On the Rates of Reactions in Solid Steel. By Edgar C. Bain. 1933 Steelmaking, Processes. By . George B. Waterhouse.

Jan 1, 1946

By H. A. Zollinger

The Hallmark Distribution Center is one of the most sophisticated material handling and order filling facilities in the world. The 53 million cubic foot facility houses an ultra-modern, computer- monitored distribution complex that handles as many as 1/4 million orders per day. The Distribution Center replaces 16 leased buildings scattered through- out metropolitan Kansas City and, in addition, re-leased 4 floors in mid-town Kansas City needed for creative and administrative expansion. This new facility is the nerve center for distribution of Hallmark products in United States and Latin America. The size and gross numbers of all parts of the system is a significant accomplishment, but the purpose of this paper is to explain the technical advancements in the state-of-the-art of material handling and controls. The system iteself is made up of seven sub-systems including receiving, warehousing, picking rack stocking, towline, order filling, order sorting, and shipping. Significant techniques were used in each of these areas as well as technical advancements in the state-of-the- art. The most significant points are in 4 of the areas and are discussed in this paper.

Jan 1, 1973

By Jack Fox

Last time there was a Take Five in these pages, it dealt largely with the matters considered by your Board of Directors at the meeting on October 20, 1970, in St. Louis, Mo. It was impossible to cover all the points worthy of discussion in the space available. So, at the end of the Take Five in the December issue of [i=], I promised to continue in the next installment. Unfortunately, I was unable to keep that promise. On December 2 your humble servant joined the ranks of those who have suffered a coronary occlusion. While I was away from the office, the very excellent SME staff team that we have built up over the years kept things going without bothering the "old man" unnecessarily. Assistant Executive Secretary, John V. Beall, Mrs. Lillian E. Donaldson, Assistant to the Executive Secretary, Mrs. Ruth Orologio, Administrative Assistant, and Mrs. Alice Ruiz exceeded even their usual dedicated efforts. As a result, the SME came up to the Centennial-Annual Meeting in great shape.

Jan 1, 1971

By Kenneth G. Arne

INTRODUCTION The real problem is finding the "appropriate" financing sources by matching the risk and reward expectations of the various classes of investors and lenders. Generally, lenders who advance funds temporarily are interested in assuming only limited risk and conversely expect to earn only a limited reward. The equity owners on the other hand, are expected to take most of the risk of the enterprise, but should receive a reward commensurate with that risk. In particular they will receive the benefit of the company's increase in net worth over time. MINE DEVELOPMENT CYCLE Consider the development cycle of a mining project beginning with rank wildcat exploration (Figure 1) [ ] Just as different professionals must be utilized at different stages, so must different funding sources be used at different points in the pipeline. Figure 2 shows the general sources of funding: [ ] This concept can perhaps be better understood if we compare the risk with the capital requirements. Suppose each area within a triangle is proportional to the risk taken (see Figure 3): [ ]

Jan 1, 1985

By K Ellis, K Quast, R Newell

The use of ammonia as a leaching agent in the recovery of copper from ores and concentrates has a number of potential benefits. These include the ability to treat ores with an acid consuming gangue, non-corrosivity, the insolubility of iron in the solution and increased selectivity. This paper reviews the previous and current use of ammonia based leaching systems for copper recovery and presents the results of a laboratory investigation that involved leaching of a copper concentrate and a low-grade ore. The effects of the operating variables (particle size, oxygen addition, agitation and temperature) are discussed. Of these, the particle size had the greatest effect, with decreasing size giving improved leaching rates and recoveries. The possibility of using ammonium salts in heap leaching is also discussed, and the results of some small-scale column leach tests presented. Possible methods for recovering the copper from the leach solution are outlined, and the types of ores and concentrates for which ammonia leaching may prove to be a viable alternative processing route are discussed.

Jan 1, 2000

By Thomas J. Feeley

The US Department of Energy (DOE) is supporting the engineering development of three advanced physical coal cleaning technologies: selective agglomeration, advanced flotation and advanced cycloning. Each is capable of significantly reducing the pyritic-sulfur content of US coals. The objective is to provide the coal and electric-utility industries with a cost-effective option for addressing the SO, emission reductions required by the 1990 Clean Air Act Amendments (CAA). A secondary objective is to evaluate the potential of advanced coal cleaning for removing trace elements that are precursors to the formation of hazardous air pollutants (HAS). The proposed National Energy Strategy (NEE) and the 1990 CAA lay a foundation for a more efficient and environmentally sustainable energy future (1991). The need to use energy resources in an environmentally sound manner presents critical challenges and opportunities for coal preparation during the next decade, particularly regarding the control of SOS and HAY emissions. The principal challenge is the development of cost-effective coal preparation approaches for sulfur and HAY precursor removal.

Jan 1, 1993

By Claude Cunningham

Blasthole pressure is the starting point for many blast design calculations, but the way in which it is usually derived, from measured detonation velocity, indicates that more thought is needed as to its true meaning and implication. The general impression is given that the energy in the hole is defined by VoD, but rarely is this the case. VoD is defined by the energy released in the Detonation Driving Zone between the shock front and the Sonic (or 'CJ') surface, and for commercial explosives it is normal for reaction not to be complete within this zone. Reaction and energy delivery continues behind it, not reflected by VoD. Thus it would be more appropriate to use the theoretical VoD, not the measured VoD, to derive the starting pressure, since this would reflect the energy input of full reaction. In decoupled situations, the derivation of pressure at the blasthole wall using a polynomial decay concept is also of debatable value, and an alternative is offered.

Jan 1, 2006

By R. Van Rijswick

Crankshaft driven piston and piston diaphragm pumps inherently generate a varying flow each crankshaft revolution. Depending on the system connected, this flow variation results in a pressure pulsation. This pressure pulsation may, depending on the structural design, result in structural vibrations. In order to limit the level of pressure pulsations, volume absorbing devices, mostly gas filled vessels, are used. The standard selection of these so-called dampeners is based on the flow variation of the pump but does not incorporate the interaction with the connected system. The paper discusses the application of a pulsation analysis tool developed by WEIR Minerals Netherlands, manufacturer of GEHO positive displacement slurry pumps. The paper first discusses the basics of pressure pulsation analysis, such as flow variation generated by crankshaft driven pumps, and hydraulic effects such as capacitance, inductance and resistance and their influence on the hydraulic response of a system. Furthermore, the relation between pressure pulsations and structural vibrations, known as fluid structure interaction, will be discussed. Additionally, the capabilities of the pump pulsation analysis tool are presented, illustrated by examples of simulation results and experimental verification.

Jan 1, 2007

By A. G. Allten

EXAMINATION by metallographic and X-ray diffraction means of an austenitic steel containing 0.06 pct C, 1.26 pct Mn, 0.38 pct Si, 21.15 pct Ni, 18.72 pct Cr, 3.07 pet W, and 9.14 pet Mo indicated that a - phase, which had not been reported in the literature, existed in this steel. Both the s and car-bides of the M6 C type were present in the as-forged steel. The carbides dissolved completely in the aus-tenite at approximately 2200°F (1205°C). The s, however, was present at all temperatures up to the solidus temperature of the steel at approximately 2375°F (1300°C). Ferrite was not found in any condition of the steel. The faintness of some of the s lines in X-ray patterns obtained from samples of the steel made it desirable to isolate the s prior to verification of its entire pattern. It was found that the s phase could be separated from samples of the steel which had been water quenched from 2250°F (1230°C) by dis-

Jan 1, 1955

PUGET SOUND LOCAL SECTION. Executive Committee. CHESTER F. LEE, Chair roan. C. R. CLAGHORN, Vice-Chairman. JOSEPH DANIELS, Secretary-Treasurer, University of Washington, Seattle, Wash. W. C. BUTLER. AL K. RODGERS. On the evening of Tuesday, Sept. 2, an informal dinner was held at the University Club, Seattle, Wash., at which the Secretary of the Institute was present, and a valuable and interesting conference took place concerning the recent activities of the Institute and the relations of the Institute management to the Local Sections. SOUTHERN CALIFORNIA LOCAL SECTION. Executive Committee. THEODORE B. COMSTOCK, Chairman SEELEY W. MUDD Vice-Chairman. FREDERICK J. H. MERRILL, Secretary-Treasurer, 300 Germain Building, Los Angeles, Cal. C. COLCOCK JONES. FRANK ROBBINS. Maintains headquarters at 300 Germain Building, Los Angeles, Members of the Institute are invited to visit these headquarters whenever they are in the city. A reception was held at the headquarters of the Section on Wednesday, Sept. 10, at 8 p.m., to meet the Secretary of the Institute and discuss Institute activities and affairs. Light refreshments were served, and about 20 members of the Section attended.

Jan 10, 1913

By G. R. W. Walker

A unique means of obtaining sea-water by G. R. W. WALKER, Pr. Eng., B.Sc. (Hons.) (Min. Eng.) (Member) Although the mining and treatment operations at The Consolidated Diamond Mines of South West Africa, Limited, are located within an average distance of I km from the Atlantic Ocean, the supply of clear sea-water in large and continuous quantities for use in treatment plants is made difficult by siltation of water-holes and the amount of sand in suspension in the sea itself. The need for sixty million litres of sea-water per day at the new No. 2 treatment plant necessitated the construction of a system that would ensure a continuous and reliable supply. Several sea-water intake schemes were proposed. This paper outlines the need for an improved means of obtaining water and describes the construction of the scheme eventually chosen - a tunnel driven through bedrock for over 400 m beneath the Atlantic Ocean. At the end of the tunnel, two large chambers were excavated from which vertical holes were drilled to intersect the sea-bed.

Jan 5, 1976

By F. X. Tartaron

F. C. Bond (Consulting Engineer, Processing Machinery Dept., Allis-Chalmers Manufacturing Co., Milwaukee, Wis.) — Papers such as this one which deal in a lucid manner with the obscure fundamentals of comminution theory are always welcome. The author has attempted to bring together several diverse theories and handles them interestingly. However, some of the ideas expressed and conclusions drawn require critical reviewing, for which amenities alone will not suffice. The author points out that the theoretical energy required to break across crystal lattices is of the order of 1000 times the actual energy required to crush or grind, and that this energy in turn is perhaps 1000 times the measured surface energy of the new surface area produced. The energy required to grind commercially is controlled by flaws and dislocations, rather than by the inner strength of the lattice structure. The measured surface energy is only a slight residue left after the face atoms are adjusted to their new environment. The dislocations in the crystal lattice structure, with a spacing of about O.l,u, or

Jan 1, 1962

It has been common practice for many years to predict and control underwater blasting effects on the basis of certain simplified theories related to the pressures generated by underwater detonations. Unfortunately, two of the most commonly applied concepts in many instances do not provide an accurate modeling of typical field conditions nor the potential for damage. One of these concepts is that the damage potential is related directly to the peak pressure generated by an underwater detonation, without regard to the time history of the pressure pulse. This belief has led to the widespread use of air bubble curtains to reduce peak pressures, without considering the effect that air curtains have on the time history of the pressure pulse. At times, this procedure can be unwise. The other concept is based on the premise that pressure pulses in solids (such as rock) will always be transmitted to nearby water bodies in agreement with the theories of the transmission of plane waves across normal (perpendicular) boundaries. In reality, such conditions are quite rare.

Jan 1, 1985

By S M. Mousavi

The issue of estimating evaporation in soils is central to the design of engineered soil caps for mine waste and landfill applications. In general, because evaporation from the soil is difficult to measure in the field, laboratory experiments and empirical methods have been used. Much of the earlier work has been conducted in soil science, although in recent years, geotechnical and geoenvironmental engineers have given great deal effort to this work. The result of this increased interest is the development of numerical models, such as UNSATH and SoilCover for estimating evaporation. In this study laboratory-measured evaporation from soil columns was compared with evaporation predicted using the computer program SoilCover, and the analytical method proposed by Gardner and Hillel. Good agreement among the results was observed. Also the sensitivity of the predicted evaporation to soil hydraulic and geotechnical properties, such as saturated hydraulic conductivity and coefficient of volume change was discussed and the practical implication of the sensitivity were highlighted. The work has application in the design and construction of soil covers over sulfide-bearing mine waste and landfills.

Jan 1, 2003

By Yousef Ghorbani, Abolfazl Danesh, Fatemeh Kazemi, Ataallah Bahrami, Morteza Abdollahi, Mohammad Raouf Hosseini

This study aims to investigate the effects of operational variables on concentrate grade, recovery, separation efficiency, and kinetic parameters of the copper flotation process. For this purpose, the effects of the pulp solids content, collector and frother dosage, and preparation and concentrate collection time were studied using a Taguchi experimental design. The results of statistical analyses indicated that the concentrate collection time and pulp density were the most influential parameters on concentrate grade. Considering copper recovery, concentrate collection time, collector dosage, and pulp density were the most significant variables, in decreasing order of importance. Also, the separation efficiency was mostly influenced by the concentrate collection time. Furthermore, kinetic studies showed that the second-order rectangular distribution model perfectly matched the experimental flotation data. The highest kinetic constant of 0.0756 s−1 was obtained from the test, which was performed with 35% solids content and 40 and 20 g/t collector and frother, respectively. The highest predicted copper recovery of 99.57% was obtained from the test at 30% solids content, and the collector and frother dosages of 40 and 15 g/t, respectively

By H. Hanemann

Discussion of the paper of H. HANEMANN and PAUL D. MERICA, presented at the New York meeting, February, 1916, and printed in Bulletin No. 108, December, 1915, pp. 2371 to 2385. JOHN A. MATHEWS, Syracuse, N. Y.-I should like to ask the authors if there is any evidence of chemical change resulting information of, alpha iron from the gamma crystals found in nickel steel of high nickel content when stressed beyond the elastic limit, similar to the effect produced by drastic cooling. Would the stresses mentioned and the drastic cooling both result in an increase in magnetic induction? I would also like to ask the authors if they have made a test of the hardness. It would be very interesting to see whether the hardness decreased under the conditions of stress, as might be the case if alpha iron were produced. PAUL D. MERICA, Washington, D. C.-While it is impossible to state absolutely, it is my belief that the effect of deformation is approximately the same as, that of -drastic cooling, but we did not make a test, of the hardness.

Jan 5, 1916

By H. R. Hanley

ELECTROLYTIC zinc produced from sulfate solution and, with pure lead anodes is always contaminated with a small and varying percentage of lead. The purpose of this investigation is to determine the characteristics of several lead alloys and their influence on the products of electrolysis and power consumption. The study of alloyed anodes has been a matter of interest for some years. Tainton, Taylor and Ehrlinger prepared a highly interesting paper1 on this subject a year ago, in which the effects of silver-lead and some ternary alloys of lead-silver-tin were described. The present paper describes a study of various combinations of 10 metals. The general plan of the work provides for the fabrication of the alloyed anode, its adequate conditioning by preparatory electrolytic operation, the production of cathode zinc and its analysis, the determination of the anode polarization, and other features. A list of the anodes tested, showing composition and polarization at various current densities together with the lead assay of the cathode zinc, is shown in Table 1.

Jan 1, 1930