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By L. K. Witika, J. H. Masinja

"Investigations of flotation characteristics of Lumwana and Kansanshi ores using formulated frothers were carried out. Of the six frothers tested, two came from the alcohol family, two from the glycol family and last two were formulated products. The initial work involved determining the optimum mesh of grind and frother dosage for Lumwana and Kansanshi ores. Further work involved carrying out surface tension, bubble size and froth stability measurements. Finally, water recovery tests were conducted at Lumwana and Kansanshi mine sites. For froth stability tests, six frothers were tested on a two-phase (water–air) system using the Bikerman column flotation cell, while water recovery tests were conducted using a total of seven frothers, including the standards for each plant. The results of the testwork showed that (i) although a stable froth is essential for optimum recovery of valuable minerals, a higher molecular weight frother, like Dowfroth 250, caused poor selectivity when used on fine ores and (ii) a lower molecular weight frother was suited for Lumwana ore, while a mid to higher molecular weight formulated product was suitable for Kansanshi sulphide ore. INTRODUCTION Investigations of flotation characteristics of Lumwana and Kansanshi ores using formulated frothers were carried out. The initial work of this project involved determining the optimum mesh of grind and frother dosage for Lumwana and Kansanshi ores. Further work involved carrying out surface tension, bubble size and froth stability measurements. Finally, water recovery tests were conducted at Lumwana and Kansanshi mine sites. In order to investigate the gangue entrainment levels in the Lumwana and Kansanshi sulphide ores, two well-known methods (froth stability and water recovery) were used. Firstly, froth stability tests were conducted using six frothers, two from the glycol family (Dowfroth 200 and Dowfroth 250), two from alcohol family (MIBC and pine oil) and other two from the formulated family (Betafroth 20 and Betafroth 245), at the University of Cape Town’s Centre for Mineral Research (CMR) laboratories. Froth formation and stability measurements were conducted using the Bikerman column flotation cell."

Jan 1, 2015

By Carl-John Grävare

This paper deals with some of the systems and equipment that are being developed and/or are in use in Scandinavia. The main subject is the development of loading tests on the piles using monitoring equipment. This paper also describes ground improvement using lime-cement columns, expander body piles and steel core piles.

Jan 1, 2000

By Torsten Wichtmann, Jan Macheck, Frederik Broz, Patrick Staubach, Hauke Zachert

The majority of heavy or strongly loaded structures, for instance high-rise buildings, large span bridges or gas storage tanks are founded on pile groups. However, current design codes and guidelines do not provide a standard procedure for their design under lateral dynamic and high-cyclic loading arising from e.g. wind, temperature or earthquake loads. To establish appropriate design strategies, a better understanding of the pile-soil, pile-pile and pile-cap interaction is required. This paper is focused on finite element backcalculations of centrifuge tests on single piles and pile groups subjected to up to 500 lateral load cycles. For the finite element simulations, a special calculation procedure is applied, combining two kinds of constitutive models, a conventional (Hypoplasticity with Intergranular Strain extension) and a special highcycle accumulation (HCA) model. The parameters of the constitutive models are calibrated based on static and cyclic laboratory tests on the sand used in the centrifuge tests. The performance of the applied numerical procedure is evaluated based on a detailed comparison of the simulation results with the measured data from the centrifuge tests. Overall the applicability of the used numerical strategy for simulating the behavior of pile groups subjected to high-cyclic loading is shown.

May 1, 2022

By B. Hart, D. J. Miller, J. T. Francis, M. C. Biesinger, Smart. R. St. C.

Diagnosis of the surface chemical factors playing a part in flotation separation of a valuable sulfide phase requires measurement of the hydrophobic and hydrophilic species that are statistically different between the concentrate and tail streams. Time of flight secondary ion mass spectrometry (ToF-SIMS) can be used to identify sufficient particles of a specific mineral phase for reliable statistics determining a mean value for each species with 95% confidence intervals (1). Using the region of interest (ROI) facility in the Tof-SIMS software, a mass spectrum from each particle, at 1-2 monolayer sensitivity, is recorded and stored. This analysis is reported for a chalcopyrite / pyrite / sphalerite mineral mixture conditioned at pH 9 for 20 minutes in order to study transfer of copper from chalcopyrite via solution to the other two mineral surfaces since this mechanism can be responsible for their inadvertent flotation in copper recovery. Analysis from mineral selection based on specific ToF-SIMS signals (eg. Pb, Zn, Cu, Fe, Fe/Cu) indicated no statistical difference in the copper intensities on pyrite and sphalerite after this conditioning. Principal component analysis (PCA) of the ToF-SIMS imaging data identifies combinations of factors strongly correlated (positively or negatively) in images or spectra from mass spectra recorded at each of 256x256 pixels in a selected area of particles. PCA is a better method of selecting minerals due to multi-variable recognition. It has clearly separated a statistical difference in copper intensities between the sphalerite and pyrite phases. The method has been extended to samples from an operating plant again with excellent phase recognition and diagnostic surface chemistry.

Jan 1, 2004

By S. F. Shaw

MINING conditions in Mexico during the current year have been most unfavorable, synchronizing with conditions in the United States, but the outlook for the near future is improving. The chief difficulties met with are because of the following conditions: severe drop in prices of metals; high smelting rates; high prices of supplies; inadequate means of transportation; low efficiency of labor. In comparison with pre-war prices for metals it cannot be said that prices are low, particularly for silver, which recently has gone to a level that would have been considered exceedingly good in 1912. But conditions have changed so greatly that only the most favorably situated properties can operate without loss.

Jan 1, 1921

OWING to the gradual depletion of the hitherto plentiful supply of firewood in the immediate vieinity of Queenstown and Gormanston, which caused a steady increase in the cost of fuel for domestic purposes, the Mount Lyell Company took steps several years ago to make available as a substitute electric current from its Lake Margaret hydro-electric supply. In order to make this practicable it was necessary that the cost of electric power for heating purposes should compare favourably with the cost, of fuel, and the installation of domestic appliances brought within reach of the average householder, and efforts have been continuously directed towards this end since the year 1928.WATER HEATERSThe installation of electrical apparatus in local dwellings began with hot-water services, the heating elements being the types then procurable on the market and adapted to meet requirements.These, however, did not prove satisfactory, but the study of their bilure resulted in a type being developed locally which has overcome all difficulties. The first type of water heater evolved was an outside circulation one the element of which consisted of an iron pipe through which the water passed, insulated with micanite and wound with nichrome wire, the latter being covered with alundun cement to keep it in position and prevent oxidation. This was insulated on its outside surface with a layer of asbestos flour, and connected to the hot-water container as shown in Fig. 1. It was found, however, that the iron pipe had a short life, due to a certain amount of acidity in the water, and a copper pipe was substituted which proved very durable. Some heaters with this improved type of element are still operating after six years of use. The resistance wire is run at a very low current density, which ensures durability.

Jan 1, 1927

By P. D. Rao

Chemical and physical properties of typical low-rank coal (LRC) ash are significantly different than bituminous coal ash. With the exception of extraneous ash, which is incorporated during mining or is due to ash partings within or between coal seams, LRC ash consists primarily of inherent ash that is bonded into the coal's organic matrix or finely disseminated mineral matter. This paper reviews the nature of LRC ash, both inherent and extraneous, and how this impacts the prospects of washing and utilizing LRCs. A literature review, as well as washability data, proximate and ultimate analyses and ash analysis of 25 Alaskan LRC seams are used as a basis for this discussion. The authors' recent research into the nature and distribution of phosphorous in an Alaskan LRC is also discussed

Jan 1, 1997

By Richard A. Brown

The direct precipitation of uranium with hydrogen peroxide has been known since 1877. Commercial use of the process began in the 1960's. During 1967 the Bureau of Mines assisted the Climax Uranium Co., Grand Junction, Colorado in the development of a uranyl peroxide precipitation process to control a molybdenum impurity problem (1). Atlas Minerals, Moab, Utah has used hydrogen peroxide to control vanadium and sodium levels in their uranium concentrates since 1969 (2). Recently, the use of hydrogen peroxide by the uranium industry has grown, particularly since the increased demand for uranium has led to the processing of low grade ores. Impurities present in low grade ores can be concentrated with the uranium during milling and will substantially complicate the refining of uranium yellowcake concentrates. Consequently, commercial nuclear fuel processors have imposed stringent specifications and penalties to control these impurities. The ability to produce a pure uranium yellowcake can eliminate penalty or reprocessing costs. Hydrogen peroxide precipitation of uranium is specific and quantitative, producing a very high purity product.

Jan 1, 1980

By B Saunders, J Carpenter

PanAust’s Phu Kham copper-gold operation (Phu Kham) in Laos is currently limited by throughput in the Semi Autogenous Grinding (SAG) mill. The ability to accurately predict SAG mill throughput (throughput) is therefore critical to accurately forecast copper and gold production. During the fourth quarter of 2016 the proportion of hard unweathered rocks in the mill feed increased, resulting in a period of lower than expected throughput. These low throughput rates prompted a study with the aim of identifying a practical solution for throughput predictions. The study identified an empirical modelling approach based on actual SAG mill throughput rates. The empirical model was then optimised by linear programming to identify the ideal feed blend of unweathered rocks to achieve a maximum SAG mill throughput.Rock strength was the initial focus of the throughput study at Phu Kham because previous studies had identified a strong link between rock strength and throughput. It was determined that there was insufficient valid data to adequately model but sufficient data to qualitatively characterise rock strength. The data identified that the weathering and lithology had a controlling influence on the rock strength. Complicating throughput predictions were operational improvements (changes to blasting and mill settings) implemented in response to the lower than expected throughput. This created uncertainty with the throughput equations. A self-learning empirical modelling method was developed to predict the throughput by incorporating fundamental rock properties with operational practices and improvements. The method is based on the proportion of mill feed with similar weathering and lithology (a proxy for comminution performance) and the actual mill throughput using the SAG mill as the analytical instrument. The modelling method simultaneously incorporated the sum and interaction of unmodelled influences including blasting, crushing and mill settings. The empirical modelling method worked at Phu Kham because the lithology and weathering has an intuitive and observable controlling influence on SAG mill throughput. The modelling method is described along with a worked example of feed blend optimisation using linear programming.CITATION:Carpenter, J and Saunders, B, 2017. Empirical mill throughput modelling and linear programming for blend optimisation at the Phu Kham copper-gold operation, Laos, in Proceedings Tenth International Mining Geology Conference 2017, pp 291–296 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

By J. F. Lupo

Leaching operations combine both metallurgical and hydraulic processes to extract metals from the ore heap. In the design of leaching operations, metallurgical tests and simple hydraulic tests are often conducted to define operational parameters such as leach cycle time, application rate, lift height, and effective leach area. While metallurgical constraints are often the primary focus on leach facility design, the hydraulic factors are also critical to the overall success of the operation. Some of the hydraulic factors that are known to impact solution flow through heaps include: • Ore physical and hydraulic properties, • Variation in ore properties under heap loading, • Ore mineralogy and its susceptibility to chemical and/or mechanical degradation, and • Heterogeneities within the heap. This paper presents a discussion on hydraulic factors that may impact the effectiveness of leaching operations. In addition, methods are presented which may be used to assess flow conditions within active and inactive heaps.

Jan 1, 2000

Council for 2005/2006 President W.H. van Niekerk President-elect R.P.H. Willis Vice-presidents Senior R.G.B. Pickering Junior A.M. Garbers-Craig Immediate Past-president F.M.G. Egerton Honorary Treasurer J.A. Cruise

Jan 1, 2006

By R. V. Ramani

Demands on available lands will continue to increase due to the projected increase in population and industrial expansion. Though there is an upper limit on the available lands, the multi-use nature of the lands will make it possible to meet these demands. However, this will not happen without adequate planning. Land uses can be broadly categorized as non-renewable and renewable. Lands with mineable resources can be dedicated at some point in time to the extraction of resources. Such a dedication, however long-term, is only temporary because of the non-renewable nature of the mineable resources. Implied here is that the land will be available before and after mining for other uses. Planning for such lands must have the objective that, as far as practicable, no non-renewable uses are pre-empted and no renewable uses are permanently destroyed. The primary aspects of this planning process will be addressed in this paper, These aspects include a discussion of planning responsibility, data needs and availability, the integration of mine planning and post-mining land use planning and a long-term plan for resource conservation and utilization. Minerals, together with agriculture and forestry products, are the primary sources of wealth. Therefore, to avoid land development that may pre-empt future mineral resource utilization, the local planning groups must be aware of the mineralization and mining potential. Much work needs to be done to identify and characterize the mineral resources. Even more work is needed in land use planning for lands with mineral deposits.

Jan 1, 1982

By Christopher F. Gleeson, Roger D. Thomas

"Abstract - Wawa has long been a center of mineral exploration activity and diamonds have been reported in the area since the 1930s. However, diamond exploration did not begin in the area in earnest until 1991. In 1993, Sandor Surmacz and Marcelle Hauseux of Saminex began a prospecting program in the area which culminated in their discovery of the "Sandor" diamond occurrence in an outcrop on the east side of the Trans-Canada Highway. They subsequently optioned the property to Spider Resources Inc. who obtained the necessary exploration permits from Algoma Central Corporation and undertook an exploration program. The diamonds at the "Sandor" diamond occurrence are hosted in the matrix of a spessartite dike composed of actinolite, biotite, and albite. Of the 64 similar dikes that have been sampled and analyzed to date, eight have been found to contain a total of 231 diamonds. Most of the diamonds are of high quality, although they are small.The dikes are non-magnetic and do not have any other geophysical characteristic that can be used to differentiate them from the adjacent country rock. All of the dikes discovered to date have been found by prospecting or by geological mapping by the Ontario Geological Survey. The dikes do not contain pyrope garnet or chrome diopside, two of the commonly used kimberlite indicator minerals. Instead, low Mg, high Cr, Zn-rich chromite, and ilmenites of variable composition, some of which lie within the field of kimberlitic Mg-ilmenite compositions, characterize the diamondiferous dikes. A regional-scale till sampling program for heavy minerals, and geochemical analysis of the <0.177 mm fraction, was used to further define the areas of occurrence of the spessartite dikes and to indicate additional areas for diamond prospecting. Heavy minerals in till that were most useful include: actinolite, chromite, and ilmenite. Geochemical analyses of the dikes show them to contain elevated concentrations of Ni and Cr and to be enriched in Ba, Co, V, Ca, Fe, and Mg relative to the surrounding rocks. Elevated concentrations of Ni and Cr in till occur overlying and down-ice of known lamprophyre dikes."

Jan 1, 2000

By G. W. Jones

As part of its program for the promotion of safety, the Bureau of Mines has investigated various means of mitigating or eliminating the explosion hazards of combustible gases and vapors found in the mining and other industries. Knowledge as to the explosive characteristics of cyclopropane in air, oxygen, and other gaseous mixtures is of both theoretical and practical importance because cyclopropane is now used extensively in anesthesia. As such an agent it has many desirable characteristics, and increased consumption of this gas may be expected if the explosion hazards now attending its use can be minimized or eliminated. The present practice of using mixtures of approximately 20 percent cyclopropane and SO percent oxygen should be discouraged because such mixtures are violently explosive and have led to fatal accidents.

Jan 1, 1940

By AIME AIME

BEFORE proceeding with the papers scheduled for the ore and foundry session*, the teller&apos;s report on the election of officers for the ensuing year was presented, a; follows: Chairman. G.C. F. MacKenzie; vice-chairmen, C.S. Robinson, J. T. MacKenzzie, C. E. Meissner; executive committee, A. L. Field, R. F. Harrington, E. F. Kenney lit. Waterhouse announced that the fall meeting will be devoted to alloy steel. This meeting will be held in Chicago the week of Sept. 22 in connection with the National Metal Congress. He also announced that oxygen in steel will be the central idea of the meeting which will be held in New York next February. The first paper, entitled "Sintering Limonitic Iron Ore at Ironton, Minn.," was presented by Perry G. Harrison (T. P. 284), the author. Sintering was first un¬dertaken in 1024 to treat Cuyuna range iron and manganiferous ores low in silica and high in moisture and containing objectionable qualities of fine... A Dwight-Lloyd machine was first installed. This machine was replaced by a larger one having a width of 72 in. The power cost was decreased from about $11.22 per ton of sinter on a 42-in. machine to about X0.14 for the 72-in. machine. The tons of sinter per man-shift was increased from 11.86 to 16.77. Improvements embodied in the larger plant reduced the cost of sintering to $0.41. The analyses of iron ore and manganiferous ore and the sinter produced from these materials was used to show the increase in value at the mine resulting from sintering. Crude iron ore actually unsalable was increased in value f.o.b. mine from a theoretical figure

Jan 1, 1930

By Martin Nevens

"In 1998, the Iron Ore Company of Canada initiated an aggressive program to improve the performance of its Carol Lake Concentrator located in Labrador City, Newfoundland. This program was termed the Concentrator Upgrade Program. The Concentrator Upgrade Program was a group of initiatives developed with the common goal of improving the overall process and operations of the IOCC Carol Lake Concentrator. The main goal of the program was to increase the annual production capacity of the concentrator from 18.0 million tomes to 21.6 million tomes. This gain in capacity was to be done mainly through improvements in process iron recovery. The target iron recovery value was 80+% versus a historical value of 70%. This improvement in iron recovery would translate to a natural weight recovery improvement from 44% to 50%.The Concentrator Upgrade Program provided the first opportunity in 30 years to make fimdamental changes to the concentrator flowsheet. To accomplish this, several pilot plants were built to evaluate new circuits. AAer 2 years, a new flowsheet was selected for the primary gravity separation circuit and the magnetite circuit. The centrepiece of the new flowsheet was the introduction of Hindered Settling Separators to the metallurgical process.The Concentrator Upgrade Program has since proceeded into detailed engineering and, as of February 2001, construction. The first one of IOCC’s 3 primary AG Mills (Mill 11) has been converted to the new flowsheet at the time of writing and is in the throes of commissioning. This paper will review the flowsheet development program in the pilot plant for the gravity separation circuit and examine the overall benefits to the operation of the IOCC Carol Lake Concentrator."

Jan 1, 2002

By A. Ignatieff

This is the first in a series of Coal Technology Reviews being prepared in accordance with a recommendation voted by the Coal Division in session at the Jubilee Meeting, Vancouver, April, 1948, that the Department of Mines and Resources be requested to arrange for publication by the proper Government authority of a Quarterly Review&apos; of Coal Technology, for distribution among those concerned in the production and use of coal in Canada. This recommendation was subsequently endorsed both by the Council of the Institute and by the Dominion Coal Board. Further reviews (or digests) will appear at intervals in the Bulletin, or will be published and distributed by the Board which, meanwhile, has undertaken to distribute reprints of Mr. Ignatieff&apos;s review.-En. * * * The fields in coal mining technology which are considered to demand most attention and study at the present time are reviewed under the headings appearing below. Mechanization In the light of the growing shortage of skilled miners and the necessity of mitigating constantly increasing mining costs, interest continues to centre in mining methods and applications of mechanization chat will produce the maximum reduction of man power. The growth of strip or open-cut mining, also, is a consequence of this trend. Mechanization at the face attracts most attention and the trend is toward developing and adopting machines capable of cutting and loading the coal in one operation instead of having the separate operations of cutting, drilling, blasting, and loading. In Great Britain, where longwall mining is? the general practice, the A.B. Meco-Moore machine still receives much attention, and accounts describing its performance over reasonably long periods have appeared in the technical press.

Jan 1, 1948

By William P. Blacutt

This paper describes the strategy, the struggles, and the obstacles encountered during the last two years in the ongoing process to capitalize Vinto. The effort involves the offering of a vertically integrated business package composed of the tin and antimony smelters along with the two principal tin mines of the country. Capitalization: Bolivia&apos;s Innovative Approach for Privatization, the Vinto Case provides a summary of hard-earned lessons. These experiences can be success- fully implemented in other nations committed to transforming their state natural resource sector.

Jan 1, 1998

Adams, Benjamin C., Jr., Student, Univ. of Oklahoma Norman, Okla. &apos;36 Adams, Ernest C., Student, Univ. of Illinois 908 W. Green St., Urbana, Ill. &apos;35 Adams, George H., Student, Colorado School of Mines Golden, Colo. &apos;36 Adams, Robert Keller Mitchell Hotel, No. 18, Golden, Colo. &apos;35 Afshar, Hadji Khan A., Student Box 63, Univ. Sta., Moscow, Idaho. &apos;36 Ahrenholz, Herman William, Jr., Student, Lehigh Univ Bethlehem, Pa. &apos;35 Alger, Robert P., Student, Missouri School of Mines & Met.Rolla, Mo. &apos;36 Allen, Paul W., Student, Mass. Inst. of Tech Cambridge, Mass. &apos;35 Allen, R. M., Jr., Student, Virginia Polytechnic Inst., "G" Co.Blacksburg, Va. &apos;35 Alley, John Arnold, Student, Montana School of Mines Butte, Mont. &apos;36 Amberger, R. H., Student, Michigan College of Min. & Tech Houghton, Mich. &apos;35 Ambrosiani, F. Peter, Student, Michigan College of Min. & Tech Houghton, Mich. &apos;36 Andersen, Burton Lee, Student, School of Mines, Univ. of Washington Seattle, Wash. &apos;36 Anderson, Carlos, Student, Univ. of Oklahoma Norman, Okla. &apos;36 Anderson, J. Wendell, Student, Pennsylvania State College State College, Pa. &apos;36 Anderson, Joseph S. Cornelia Hotel, Ajo, Ariz. &apos;35 Anderson, R. C., Student, Univ. of Washington Seattle, Wash. &apos;35 Anderson, Roy A., Student, Washington State College Pullman, Wash. &apos;35 Anderson, Willard. Student. Univ. of Oklahoma Norman, Okla. &apos;36

Jan 1, 1936

By Klaus Pronold

Once installed rolling mills can look forward to a long life. Around 40% of the 140 conventional hot strip mills presently in operation were built between 1960 and 1970. 17 of the 29 CSP®-plants were commissioned before the year 2000 and have automation platforms that are obsolete and/or have outdated rolling technology. Keeping pace with the market requirements is an ongoing challenge for producers of flat steel. It is a real balancing act keeping production facilities performing at necessary levels, safeguarding the investment and keeping outage periods to a minimum. To overcome these demanding factors and strike the right balance allowing for the production of higher grade steel that meets the current market price the installation of mechanical equipment as well as automation platforms and process technology must meet the latest technology standards. Being discussed in this paper are the different motives for modernizations along with their impact on project handling and commissioning philosophies. Experience gained during recent modernization projects in the field of flat steel rolling relating to Steckel / plate mills or current CSP® modernizations will be shared and demonstrate that each modernization has its own individual solution. Specific strategies are explained to help optimize production, increase plant agility and maximize the return on investment.

Aug 17, 2017