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By A. E. Wraith, R. Harris, J. Qiu, R. Parra

Small pilot scale experiments have shown that it is possible to almost fully eliminate the minor elements (ME), namely As, Sb, Bi and Pb contained in smelter dusts by vacuum calcination of mixtures of the dust with sulphidizing agents such as dirty copper concentrate or elemental sulphur at 900 °C and 80 +/- 30 Pa for 90 minutes. The products of this calcination are a residue comprising a purified mixture of copper containing compounds along with the gangue constituents and a high sulphur condensate comprising a mixture of the minor element compounds. In particular, the Cu:ME ratios of the concentrate and dust were increased from 250 and 50, from 28 and 12 and from 36 and 8 to roughly 3000, 3000 and 100 for the calcine, for Bi, As and Sb, respectively. It has also been calculated that (i) the copper content of the vacuum calcine may be recovered by feeding it into a Peirce-Smith converter during its slag blow, and (ii) the resulting recycling could increase the minor element treatment capacity of a smelter by 100 % while also reducing the blister As content by a factor of three. The experimental results are briefly discussed and a treated dust recycling option is examined. Example operating conditions are presented and available commercial technology for the vacuum calcination of the mixtures is reviewed.

Jan 1, 2007

By Gisell Sumaria, Mike Martos

La analítica avanzada permite analizar los datos (en tiempo real, históricos, no estructurados, estructurados, cualitativos, cuantitativos, etc.) para identificar patrones, optimizar indicadores, mejorar procesos, generar conocimientos para informar y, en algunos casos, resolver conflictos con una mínima intervención humana, es decir, automatizar decisiones. El proceso analítico ha demostrado ser un excelente aliado para la toma de decisiones, o inclusive, desde el origen hasta la decisión, control y seguimiento de resultados del proceso.

Sep 29, 2023

By E. G. Joe

"This paper summarizes the main conclusions derived from twenty-two technical presentations made at the 1973 meeting of the Canadian Mineral Processors. Results of two surveys with response from over seventy mines were reported on Canadian milling practice for water re-use and on elimination of cyanide from mill effluents. Water and solution recycle in Canadian mills were detailed for copper, copper-zinc, lead-zinc-copper, nickel-copper, iron and gold mines. Cyanide elimination from mill effluents was reported under current practice and under requirements for further treatment by various other processes. Three recent process equipment entries into Canadian mills have been the on-stream particle analyzer, the new gravity concentration tables for recovery of fine tin and other heavy minerals, and solution-jet slurry equipment for reclaiming ground ore from storage. The principles of operation of this equipment were described along with the practical limitations that were found in their application to mineral processing. Capital costs and milling cost reductions were shown in some operations. Computer control of flotation mill processing was a major item on the program. Four major mining companies outlined their mill process control strategy, computer programs and on-stream analysis equipment. Some capital costs and personnel changes were presented, together with gains in concentrate grade and mill recovery. Recent development work has shown the effect of the type of grinding and of aeration on the recovery of sulphide minerals in flotation. One mining company reported a significant depressing effect on copper sulphide flotation while floating ore ground with mild-steel balls; also, pyrite appeared to be activated in the subsequent zinc flotation step. One company with extensive experience in the application of aeration to copper sulphide flotation showed significant improvement to copper recovery by pre-aeration. Both the effects of grinding and aeration were subject to the constraints of the chemical condition of the ore pulp. The metallurgy of silver recovery by combination grinding - gravity treatment and of gold recovery from a complex gold-sulphide ore were reviewed in two papers on precious metals. The latter paper further described the recovery of gold from the Cottrell collectors and the final disposal of arsenic from the dust collectors."

Jan 1, 1973

By Thomas Darlington

The obligation of an employer to the State requires certain things of him as matters of good citizenship: for instance, that his workmen shall have a living wage, that child labor shall not be employed, that injuries from accidents shall not make workmen a charge upon the State, and that the laborer's children shall have opportunity for education and to become good and useful citizens. Affairs of this kind are not taken up as philanthropy, for the officials of a corporation or a large manufacturing concern may not feel at liberty to spend the funds of their company as prompted simply by motives of kindliness; but they may spend company money on such matters because it is good business. For years, the poisonous effects of lead, phosphorus, and dust have been emphasized in books on industrial hygiene and their elimination has been urged; but the more important and everyday physiology of the workman himself has been neglected. Part of my object in writing this paper is to show how our knowledge of physiology may be applied to working conditions in everyday life. In the interest of industrial laborers, accident compensation laws have been enacted in 33 States. This has been carried forward rapidly, because it has been shown that it pays both employer and employee. A further step is the recognition of sickness and disablement independent of accidents, not only because of their immediate cost to the worker and to the employer, but because continued efficiency in work and business depends largely upon health. Some measure of the importance of health in industry can be gained by the knowledge that records kept by some companies which now make this the subject of careful inquiry show that the time lost by employees, through illness, is several times as much as that lost as the result of industrial accidents. It is true that accidents frequently result in permanent disability or death, but it is equally true that illness is also a cause of permanent disablement or death. Thus the chief difference is that the loss to the employee through accidents occurring in the course of his employment is now generally recognized as a cost

Jan 1, 1918

By Rudolph H. Jacobson

The leaching of heaps or sub-marginal waste ore dumps as it is practiced throughout the Southwest as well as other parts of the world, is the major method of secondary recovery of copper. In 1970, twenty percent of all domestic copper was produced by dump leaching operations (l). In recent years, this method has been successfully extended on a limited scale, for the recovery of uranium from low-grade ores (2). It is inevitable that this technique will be increasingly employed in metal production to satisfy the insatiable demand of our mineral based society. Although dump and heap leaching has been used effectively for some time (3) , its application has been more of an art than a science. Therefore, it is essential that we learn about the important factors and parameters affecting this versatile process so that we may make increasing use of this technique in the future. The dump or heap leaching process encompasses the preparation of ore for-subsequent inplace leaching, the flow of solutions and ionic species through porous rock masses, the leaching of minerals with inexpensive and, if possible, regenerable lixiviants under prevailing conditions of the inplace environment, and the recovery of metals from the pregnant liquors. It is evident that this comprehensive scope of dump or heap leaching falls under the realm of interdisciplinary science and engineering requiring the application of the principles of physics, mineral engineering, hydrology, computer modeling, operations research, economics, and allied disciplines. An exhaustive study of the phenomenology of a leach dump or heap requires detailed knowledge of the simultaneous interaction of'

Jan 1, 1972

By John A. Hansuld

Molybdenum presents a series of baffling geo- chemical puzzles. It can exist in six different valence states, possessing three different coordination numbers. As a result, it combines with other elements to form a wide variety of negatively and positively charged ions and complexes whose exact chemical nature are relatively unknown. Its rather complex chemistry might be described as "ambidextrous, bi-sexual and polygamous". It is little wonder then that the geochemistry of molybdenum is relatively unknown, and compared to most common metals its geochemical behavior is somewhat unique. The behavior of a particular element or metal, such as molybdenum, in a given dispersion media is largely controlled by the stability relations among its various oxidation products. Recognition of these products and an understanding of their stability relations is therefore a prerequisite to a proper understanding of its observed behavior. Because most secondary dispersion media represent aqueous chemical systems, stability relations are best expressed as functions of Eh and pH.

Jan 12, 1966

By William Gleason

With its 2011 acquisition of rival equipment company Bucyrus International, Caterpillar added underground mining and large shovels to its line of products and further solidified its standing as the leading mining equipment manufacturer in the world with solutions for every aspect of mining. When Caterpillar spent $8.8 billion to acquire Bucyrus, the global mining business was flourishing, as mining companies around the world worked to keep up with demands for nearly every commodity. Flash forward to 2013, and the global mining landscape looks very different. Lower demand for raw material from China and India and falling commodity prices have forced most mining companies to pull back on their production. The reductions from the mining industry have hit equipment makers like Caterpillar and Komatsu hard. In October, Caterpillar reported that its quarterly earnings had fallen 44 percent. The changing conditions have also changed the narrative from Caterpillar and other equipment makers to customers from offering solutions to move the most tons per hour, to now offering solutions for the lowest cost per ton. In September, Caterpillar hosted some of its mining customers and the trade press at its Tinaja Hills Demonstration and Learning Center near Tucson, AZ to talk about its range of products, from its MineStar System designed to help increase efficiency through better equipment management and planning, all the way up to the massive Cat 7495 and 7495HF electric rope shovel lines acquired through the Bucyrus takeover

Dec 1, 2013

By Glenn L. Krum

Inflation has received much attention due to its effect on capital budgeting, associated cost overruns, and declining real profits. This study focuses on the effects of inflation on the evaluation of a mining investment and the estimation of a mining project's revenues. The study indicates that the best method for estimating future returns is the fore- cast dollar scheme. In this scheme, the metal price was held constant, and the operating costs were "inflated" along a historical regression line. The conclusion was reached by comparing the "actual" performance of a 3000 tpd (tonnes per day) lead mine model with 'its estimated performance during four time periods (1950-1960, 1955-1965, 1960-1970, 1965-1975). The individual data files for each time period and estimating method (6 files by 4 time periods) were pro- cessed by a suite of cash flow computational and investment analysis sub- routines. The analysis presumed that the mine was part of a large corporation which could utilize the expensed, development and exploration costs and any investment tax credits, in the year that they were incurred.

Jan 1, 1979

This paper addresses, in particular, the influence of winding depth on the selection of head ropes for Koepe winders. Because this is just one aspect of winder design that affects the operational safety of the winding system, the paper starts by considering all the issues governing the life and safety of the winding ropes. Regulations from a variety of countries are reviewed and comparisons of the legislated rope factors of safety and their variation with winding depth are made. This is followed by a discussion of the typical observed mode of in-service deterioration of Koepe head ropes. This mode of deterioration is due to fatigue and is influenced by the load range occurring in the ropes. Parameters contributing to load range are discussed and the influence of winding depth is highlighted. Lessons learned from early experience with very deep Koepe winders in South Africa are recalled. Predictions of load range as a function of depth are made, from which general rope life predictions are made for ropes selected by conventional national factor of safety requirements. This is illustrated in graphs comparing rope life as a function of depth. Typically a reducing life with depth is predicted. A rope selection strategy is advocated, which is based on achieving a constant rope life irrespective of the depth of wind. A new factor of safety (or rope design factor) equation is prepared that has the trend of increasing with depth. This proposed equation is compared with other published proposals that promote an increasing rope factor of safety with depth. It is shown that smoother winder drive controls enhance winding rope life and this improvement is quantified. The paper concludes by pointing out the consistency in predicted and observed life of winding ropes selected in accordance with legislated factor of safety approaches. It recommends the adoption of a new rope design factor equation for rope selection, to be used in conjunction with appropriate codes of practice for winding rope condition assessment and for the design, installation, operation, maintenance and testing of Koepe winders. The new rope design factor equation approaches a limiting economic depth of wind at shallower depths than the existing Koepe factor of safety approaches. However these older approaches æbuild-inÆ a reducing rope life with depth. The new rope design factor is therefore a more consistent way to select Koepe ropes and to evaluate economic trade-offs between Koepe and conventional double-drum or Blair winding systems.

Jan 1, 2005

As we look back through the Proceedings of our Institute, we find few papers dealing directly with education and recruitment. Apart from papers prepared in the earlier decades of this century, there was little written discussion on the subject until the 1950s, and mostly this was by the professionals, the professors and lecturers who staff the various mining schools of Australia and New Zealand.I use the term "mining school" in its fullest and widest meaning, to cover all aspects from ore to metal, and not in the narrow meaning that the word might imply. At the same time, in restricting the parameters of this address to "ore to metal" I recognize that I am excluding the very important fields of physical metallurgy and materials science; this I do because there is a limit to the quantum of any paper, and in fact these subjects are more closely allied to the use rather than the production of metals.However, the lack of education papers does not mean that education has been regarded lightly by The Institute. Sir Maurice Mawby in his presidential address in 1968, reminded us of the original objectives of The Institute, one 'of which was, "To promote the arts and sciences connected with the economical production of the useful minerals and metals ...". Our present Royal Charter is more specific when it says that one of the objects of The Institute is, ". . . to encourage the study of engineering with special reference to mining and metallurgy ...". If we recognize that in itself membership of our Institute is one means of continuing our education, it is true that education has been a concern of The Institute since it was first founded.Occasionally in recent years, an intrepid president has ventured to tell the academics what the industry needs, and he generally does this in a "no-question" situation! However it is encouraging that those entrusted with mineral education have always accepted this; they keep coming back for more and ask us to tell them what we want, and they will provide it.In 1948 a considerable dialogue on education was initiated when a standing committee was established by the Council of The Institute. In the period 1949 to 1951, three papers were prepared under the chair...

Jan 1, 1974

By V. E. Dawson

Brake testing of large mining trucks was initiated in British. Columbia in 1969 following an accident involving the failure of the service brakes of a l00-ton electric-drive truck. Some selected results of the 1976 brake test program are presented and discussed ?in this paper . The tests were conducted on end- dump trucks having load capacities ranging from 85 to 235 tons. All tests were made with the vehicles fully loaded operating on downhill grades varying from 8 to 10 %. Stopping distances were measured from initial speeds varying between 10 and 39 mph. The results are adequate, in most cases, to determine the "ultimate" capabilities of the service brakes of varying models and sizes of haulage trucks operating in British Columbia mines.

Jan 1, 1977

Semisoluble salt minerals are characterized by their ionic bonding and are distinguished from soluble salt minerals by their limited solubility in water. One group of semisoluble salt minerals being considered is the alkaline earth salt minerals, including fluorite (CaF2), calcite (CaCO3) and apatite (Ca5F (PO4)3), as well as celestite (SrSO4) and barite (BaSO4). Another group of semisoluble salt minerals being considered is the rare-earth salts, which include bastnaesite ((Ce, La) CO3F), monazite (CePO4) and xenotime (YPO4). Surface chemistry features of these selected semisoluble salt minerals are discussed with respect to flotation separations. First, the surface chemistry features of alkaline earth semisoluble salt minerals are reviewed, and then the surface chemistry features of rare-earth semisoluble salt minerals are examined. The discussion includes electrokinetic behavior, wetting characteristics and collector adsorption.

By J. J. Shields

This is the Seventh of a series of publications that describe methods and practices used in mining bituminous coal mechanically.3/ This report deals with the operation referred to in coal mining as continuous mining, and the interest shown by mining companies in this method is the reason for this study. Only continuous mining as it applies to the room-and-pillar system of mining, or a modification thereon, is discussed in detail in this report. Although not always as continuous as the name implies, it is a system of mining in which a machine is used to cut and load coal in one continuous operation without drilling and blasting the coal. With the mining equipment in most general use today, the usual cycle of operation in mining of coal is: (1) Timber, (2) cut, (3) drill, (4) blast, and (5) load. As the phases of this type cycle cannot be performed simultaneously in the same working place, it is necessary to operate from 3 to 7 working places so that at least 1 place is available for coal loading at all times. Even if the schedule of the phases in a cycle is maintained, coal production ceases during the time required to move the loading equipment from one loading place to the next. In 1920 a continuous-type mining machine4/ was installed in an Illinois coal mine to drive entries. Several other companies used these entry drivers for short periods in the following few years. In 1927 a southern Illinois coal company installed 2 of these machines which, in the next 25 years, were reported to have driven over 200 miles of entries. The machines did not attain widespread usage.

Jan 1, 1954

By D. Malovichko

Seismic events and pillar failures observed in two platinum mines in the Rustenburg area, South Africa, were investigated. We studied the sources of approximately 300 largest seismic events recorded in 2009. Moment tensors of these events were estimated from amplitudes and polarities of P- and S-waves. The inverted mechanisms contain isotropic implosive components in many instances. Analyses of uncertainty of the moment tensor solutions confirmed the significance of the implosive component in general. Several documented cases of pillar failure were considered in detail. For each of these a seismic moment tensor was calculated from an elastic stress model assuming an instant removal of a failed pillar. The geometries and magnitudes of the theoretical seismic moment tensors are in agreement with the observed (i.e. inverted from seismic data). The results indicate that either pillar failure or fracturing in the proximity of the reef (within a fraction of the dominant wavelength of seismic waves) are responsible for a significant portion of the large events recorded in these mines.

Jan 1, 2012

Extremes in temperature and weather, along with the highly corrosive nature of acid leach solutions used at open-pit copper mines, necessitates the use of pipeline systems that are both corrosion resistant and impervious to the environment.

Jan 6, 1976

By Derek J. Barratt

The specification of the prime mover of an autogenous/semi-autogenous mill involves an analysis of the likely operating conditions within the mill and the choice of a nominal operating speed. For variable speed mills, the operating range for mill speed has to be defined so that mill power/torque requirement can be matched by the motor power/torque capability. This paper will describe how this relationship can be influenced by ore grindability.

Jan 1, 1993

By Paykan Safe

?? Background ?? WorleyParsons Gas Cleaning ?? PT Inco Smelter ?? Process Design Considerations ?? Furnace Control and Combustion ?? Combustion Chamber ?? Spray Chamber ?? Draft Control ?? Baghouse ?? Secondary Ventilation ?? ID Fan ?? Dust Handling Equipment ?? Project Execution ?? Heat Recovery ?? Conclusion ?? WorleyParsons Gas Cleaning ? Irving, TX ?? Formerly Gas Cleaning Technologies ?? Acquired by WorleyParsons in 2005 and now part of a global EPCM company ?? 14 years experience in off-gas system design for ferrous and non-ferrous facilities worldwide

May 1, 2008

By Tap Pryor

A very small nation with large seabed resources requires a strategy. The simplest approach is to duplicate every step taken by the United Nations (UN), in its own leasing programme. In addition, the smaller nations must sell itself and its competitive offering. It is one thing just to await applicants and/ or tenders, another to work to make the leasing seem like a very good idea. This cap be achieved through publications, correspondence, meetings (such as the Underwater Mining Institute, but especially through pro-active planning, seeking the ideal technologies in both harvesting and processing. The ideal would be some combination that could begin quickly and on a small scale. It must be within the UN environmental guidelines. To meet the "quick and small criteria," simple harvesting and physical processing methods must be given the highest priority. Once these are satisfied, then marketing studies can be completed. There is, of course, a market for every element but only careful engineering and cost analysis will determine accessibility. What is required is a stepwise approach, gaining greater and greater credibility at each step. In fact, much planning can be done for very low cost. In the Cook Islands, the first crucial step was the East-West Center publication which pulled together all facts in one volume and which found the local resource to be richer in significant ways than Clarion-Clipperton. Most seem to believe that it could be many years before full production is possible, but this has been conventional wisdom for so long that it has taken on the suspicious aura of myth. Is it real? Have all possible recent technologies such as robotics and physical processing been taken into account? Either way, it is essential that a comprehensive approach be taken so that all factors from resource to market are considered as inter-related until a single business plan emerges. When that is in hand and when its profitability and risk levels are found to be credible, adequate investment funds are available.

Jan 1, 1994

By Robert Hopler

Your petitioner further alleges that at various times, to wit, from 1872 until June 30, 1895, during the existence of the combination and conspiracy in restraint of trade among the various States herein- before described, there were organized under the laws of various of the several States of the Union various corporations having for their object the manufacture and shipment and sale of a high explosive commonly known as dynamite, which said explosive is commonly used for the same purposes as those for which blasting powder is used;

Jan 1, 2013

By Randy McMeekin, Chris Twigge-Molecey, J. Peter Blake

The business objectives of a metallurgical project determine targets and constraints, such as the range of products, production capacities, in-service dates, and capital and operating cost parameters. Permitting is usually left to the project team, as are decisions regarding site location, technology, and construction approach. Success requires an orderly methodology, represented in this book by front end loading (FEL) phases: FEL1 examines several alternative approaches; FEL2 ranks and eliminates less economically or technically attractive options; and FEL3 develops the preferred option to the point of major permit completion, with defined scope, schedule, and cost to submit for approval to proceed with implementation in FEL4. Working through FEL1, FEL2, and FEL3, the project definition improves, estimates become more accurate, and project risks are reduced. The project design basis at the end of FEL3 is the control document for project implementation in FEL4.

Jan 1, 2015