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By John Drew Ridge

Tables showing world trade in metallic mineral raw materials during the years 1953 through 1957 have been prepared for the following twenty-one commodities: alumina, aluminum, bauxite, chromite, copper concentrates, partly refined and fully refined copper metal, iron ore, pig iron, iron and steel (simple shapes), lead concentrates, lead metal, manganese ore, mercury metal, nickel ore, concentrates, and matte, nickel metal, raw pyrites, sintered pyrites, tin concentrates, tin metal, zinc concentrates, and zinc metal. In each instance, the amounts given by the importing country were used except when statistics from the importing nation were lacking, incomplete, or misleading. To show the considerable divergence between importing and exporting country totals for the same years, the complete mercury table is given and, in parallel columns, shows the comparable tonnages of importers and exporters. Tables for the other twenty commodities are presented in summary form. The data of the concentrate tables are used with those of the corresponding metals as a basis for a discussion of trade in concentrates versus trade in metals. The data of all twenty-one tables provide the basis for testing the thirteen rules governing international trade in metal raw materials which I first published in Mining Engineering for July 1955. Because the 1953 through 1957 data are far more complete and considerably more extensive than those on which the 1955 rules were based, it was found possible to deduce five additional rules and to modify three of the original thirteen appreciably. The full text of the eighteen rules is given.

Jan 1, 1960

RME has a vision for a new grinding plant operational paradigm made possible by RME's fast, safe Mill Relining System. Some new liner designs can degrade SAG mill performance because of mill volume loss, ball strike (rotational speed limitations) and other issues often brought about by modifying liner design for maximum life and without a backward glance at metallurgical consequences. Freshly relined mills can initially produce as little as 80 per cent of their maximum throughput, that maximum occurring toward the end of the liners' wear life. RME's proposition is to see new liners designed for maximum commercial performance. This may mean more frequent mill relines but with liners designed to yield optimum grinding, metallurgical and profitability performance, not maximum life. In other words, mill liner profiles and mill relining speed become key operational controls and not simply `must do' maintenance functions. Taken to the extreme, liner profiles may prove capable of `tuning' a grinding plant for maximum profitability in any metal price environment. Following the introduction, the first section of this paper provides an update describing recent and significant developments within RME's range of Mill Relining Systems, the enabling technologies which permit more frequent liner exchange without incurring additional downtime imposts. The second section outlines RME's vision of a `liner profile versus profitability' commercial model, developed either intuitively or by using a combination of new measurement and modelling technologies. These new measurement and modelling tools provide the opportunity to predict the optimum commercial outcome, off-line in the virtual world, before committing to an expensive liner experiment.

Jan 1, 2007

By A. Eslami

In recent development of piled raft design, the contribution of both raft and piles to tolerate the loads is taken into account, depending on the stiffness and contributions of involved elements i.e.; piles, raft and surrounding soil. The piles are usually required not to ensure the overall stability of the foundation but to act as settlement reducers. One alternative method of foundation design is therefore to introduce piles purely as a means of improving or enhancing the stiffness of the base soil by structurally disconnecting the piles from the raft. In this paper, two and three dimensional finite element analysis of disconnected pile-raft systems are performed on three case studies including a 12-storey residential building in Iran, a 39-storey twin tower in Indonesia, and the 256m height of Messeturm tower in Frankfurt, Germany. The analysis include different geometrical parameters, e.g., pile spacing and embedment length, arrangement and raft thickness for foundation system to obtain the optimized design functions and to clarify the role of each parameter and method of analysis. The parametric study results and comparison to a few field measurements indicate that by concentrating the piles in the central area of the raft foundation leads to the optimum design with the minimum total length of piles. This achievement can be considered as a criterion for project cost efficiency. On the other hand, disconnected piled-raft systems can significantly reduce the settlements and raft internal bending moments. Finally, the comparison indicates that simple and faster 2D analysis has almost the identical results to 3D analysis which is complicated and time consuming.

Jan 1, 2008

By Jay L. Hodkinson

Replacement of an aging twin span river crossing in Vermont required a temporary bridge to accommodate traffic during construction. Soils beneath the temporary approach embankment consisted of very soft organic clayey silt underlain by interbedded, loose alluvial fine sand and silt/clayey silt. Reinforcement was required for the southern temporary approach embankment to limit settlement and to increase global stability factors of safety. A ground improvement design was developed using Rammed Aggregate Pier® reinforcement and was included in the contract documents as an FHWA Category II Experimental Feature. Instrumentation intended to document the performance of the supported embankment was installed. Piers were then constructed and monitoring commenced as embankment and bridge construction occurred. Weekly instrumentation data reports indicated continuing excess pore water pressure, settlement, and lateral deformation of the subgrade soils as the embankment and temporary bridge abutment was constructed. In response to the unanticipated monitoring results, further investigation indicated that significant deviations from the conditions and basis upon which the ground support design was developed were made during construction. This paper discusses these deviations and their specific impacts to embankment support performance, how these deviations occurred, the role that the ground support system played in maintaining global stability, measures taken to limit further detrimental impacts to the embankment, and provides recommendations for contract document preparation and construction oversight to prevent similar situations from occurring on future projects.

Jan 1, 2011

By Adil Aledresse, N. Emre Altun, Bern Klein, Nuri Hmidi, Brent Hilscher

A study was conducted to investigate high gold grades in water lines and carbon fines collected from the Musselwhite gold recovery circuit. It was discovered that fine magnetic particles in the overflow from the carbon fines settling tank launder had high gold grades ranging from 2,000 to7,000 g/t. The -37 micron fraction had up to 17,000 g/t gold. Scanning electron microscopy revealed the gold was attached to the surface of iron particles. The objective of the study was to identify possible mechanisms that result in the attachment of the gold to the magnetic iron particle surface and to recommend process modifications that would reduce these types of gold losses around the carbon circuits. Solid and solution samples were collected from the gold recovery circuit and analysed. Two possible mechanisms were identified including gold cementation onto iron and heterocoagulation of colloidal gold onto iron oxides in the elution column. Possible sources of the colloidal gold include reduction of gold cyanide complex to metallic gold in the carbon regeneration kiln and gold detached from cathode in EW cell. Based on SEM+EDX, the sources of iron were natural magnetite and roasted iron sulphides. Thermal reduction of gold is believed to be the cause of dendritic gold from the carbon regeneration kiln.

Jan 1, 2014

By Mark S. Stagg, David E. Siskind

The mining industry occasionally blasts near pressurized transmission pipelines and has requested guidance of safe vibration levels and setback distances. the Bureau of Mines and the Indiana Department of Natural Resources cooperated with AMAX Coal Company on a study of coal mine overburden blasting. Five buried and pressurized 250-ft pipeline sections were specifically installed on the Minnehaha Mine highwall near Sullivan, IN for testing to failure. Four welded steel pipes ranging from 6- to 20- in diameter and one 8- PVC water supply pipe were monitored for vibration, strain, and internal pressure for a period of 6 months while production blasting advanced up to the pipeline field. In contrast to previous studies of small-scale blasting representing construction activities, these tests involved overburden blasts of up to 2100 lb per delay in 12-l/4-in diameter holes.

Jan 1, 1996

By W. A. Calhoun

This report gives results of metallurgical investigations performed by the Bureau of Mines on mineral samples taken during April 1959, from Hawaiian bauxite deposits on the islands of Kauai, Maui, and Hawaii. The bauxite samples were tested at the Bureau's Rolla Metallurgy Research Center, Rolla, Mo., to determine if alumina could be extracted. The results were encouraging. Extraction of the alumina by the American Bayer type digest of crude ore samples from Kauai, Maui, and Hawaii recovered 78.8, 73.1, and 70.0 percent, of the total alumina, respectively. These recoveries were increased to 82.8, 85.5, and 79.5 percent by modifying the treatment, which consisted essentially of calcination and weak caustic desilication to provide a residue. The residue was then treated with calcium oxide and digested in a strong caustic solution to extract the alumina.

Jan 1, 1962

By K. Viking

The vibratory characteristics of full-scale sheet piles, vibratory driven into the ground, have so far not been described systematically in detail. This paper concerns the preliminary results of a series of full-scale field tests where both the driveability and induced ground vibrations have been continuously monitored. Furthermore, the results of measured ground vibration levels have been measured at two different sites characterised as having hard and easy driving conditions. In the light of the presented results, the paper briefly discusses how the complexity of a driveability and vibration prediction can be subdivided into three parts, namely, vibrator-, sheet pile-, and soil-related parameters, all of which significantly affect both the driveability and induced ground vibrations.

Jan 1, 2000

By R. A. Halatchev

A risk model for assessment of the uncertainty in the forecasts of the planned profit is developed. It is based on the selling price of the metal recovered from the ore and the production per shift of the excavators. These two critical variables characterise the economic and technical aspects of the mining venture. Time-series methodology is used to describe the behaviour of the economic variable, which improves the adequacy of the modelling. A hypothetical open-pit gold mine is used to illustrate the application of the model. Results obtained show that the model is a good alternative to sensitivity analysis in taking account of the stochastic character of the price of the metal recovered from the excavated ore and the production per shift of the excavators used. The model can be extended by the inclusion of new variables that have a probabilistic nature

Dec 1, 1996

Under the Town and Country Planning Act 1977 the Ministry of Works and Development has a responsibility for providing information to local and regional planning authorities on public works and matters of national development and importance, for the exercise of their responsibilities under this Act. One such matter which has recently become a source of concern is the development of South Island lignite. In 1979 the Ministry of' Energy produced a position statement outlining a programme of' research leading to the possible extraction of lignite in Southland or Central Otago for conversion into about 50 per cent of New Zealand's liquid fuel requirements by 1995. Understandably this possibility has caused considerable concern at the local level, expressed particularly by bodies such as Federated Farmers and the local authorities. In the absence of any factual knowledge short of mere conjecture been able to recommend to local authorities is that they limit their planning period to ten years. After this time more information regarding the size, nature, location and certainty of the proposal will permit a more accurate assessment of the implications of the York. While on holiday earlier this year I took the opportunity to visit opencast mining areas in Germany and England to gain an appreciation of the scale of impacts involved and discuss with those concerned the procedures used in planning for such operations. What follows is a brief description of these operations, a comparison with the likely development in this country and the extraction of what may be some relevant principles of' operation for the planning of an environmentally acceptable project. Please note that the views expressed in this paper are mine alone and are not necessarily those of the Ministry of Works and Development.

Jan 1, 1981

By J. R. Long, A. H. Roberson, T. R. Graham, R. S. Dean

EXPERIMENTAL work on the properties of high-purity alloys of the copper-manganese-zinc system has necessarily required extensive metallographic work to determine the equilibrium conditions in this system. Previous work on these alloys is fragmentary and, unfortunately, based on alloys made with impure grades of manganese, thus introducing significant amounts of iron, silicon, aluminum and carbon. Since these elements are known to affect equilibrium conditions, it became desirable to re-examine these alloys made from the pure metals. The alpha solid solution field was of particular interest and, therefore, was chosen for the initial work, which was outlined to determine the composition limits of this field. PREVIOUS WORK Heusler1 conducted an extensive survey of the liquid-solid regions of this system and also made an estimate of the solid-phase boundaries at 340°C. The pertinent part of his diagram is given in Fig. I, but it is of limited usefulness, since it applied to a single temperature only and is based on impure alloys under admittedly nonequilibrium conditions. Bauer and Hansen,2 likewise working with impure alloys, have determined the phase boundaries for alphabeta brasses containing small amounts of manganese and indicate an increase in the extent of the alpha field with increasing manganese. This is not in accordance with Heusler or with data obtained on pure alloys.3 They also described a third constituent precipitating in the alpha plus beta field below 350° to 400°C. but did not identify this constituent. Guillet4 and Heike and Ledibur5 have also noted this precipitate Each of these investigators recognized that impurities present in the manganese could and did have an effect on the structure and properties of their alloys. Corson6 in particular pointed out the hardening effects of silicon, aluminum, and carbon in copper-manganese alloys and Heusler reported that his alloys containing more than 25 per cent manganese were extremely brittle. In all probability this brittleness was due to the impurities present. This early work, therefore, should be taken as a general guide for preliminary studies only, and high-purity alloys may be expected to produce different results. The work of the Bureau of Mines laboratories with electrolytic manganese has been briefly summarized by Dean7 but includes only a short section on this system. Later work3 outlined a limited portion of the alpha field in the neighborhood of 65 per cent copper, 10 per cent manganese, and 25 per cent zinc. The present work was under-

Jan 1, 1945

By Dilip I. Patel, Jesus Schabib, W. Allen Mawr, Daniel A. Louis

East Side Access (ESA) will extend Long Island Rail Road into midtown Manhattan via 11 km of tunnels, a new terminal station and associated rail support facilities. The hard-rock tunneling in Manhattan will traverse under Park Avenue and some of the most historically and commercially significant real estate in the world. The soft-ground tunneling in Queens will traverse beneath Amtrak’s Sunnyside Yard and the Harold Inter locking, the busiest rail interlocking in North America. This paper details ESA’s program-wide geo-instrumentation monitoring system for obtaining, processing and presenting all geotechnical monitoring data. Data streams will be real-time, such as from automated total stations, and manually read, such as from optical survey instruments and handheld data loggers. All data will be input into a web-based Geo-Instrumentation Data Management System, which will be accessible to project stake holders via ESA’s intranet or via the Internet using remote access controls.

Jan 1, 2007

By J Nell, J Petersen, X C. Goso

The feasibility of increasing the deportment of titanium species and the stability of the pseudobrookite solid solution (M3O5) in a titaniferous slag was investigated, to facilitate the valourisation of titaniferous slags. Thermochemical simulations using FactSage™ software, ver 8.3 (by Thermofact/CRTC and GTT-Technologies), and equilibration-quench experiments were conducted using an appropriate synthetic titaniferous slag composition in an oxygen partial pressure (pO2) ranging from air to 10-16 atm under non-isothermal conditions. The temperature-pressure phase stability diagram for the synthetic slag containing 37.19 per cent TiO2, 19.69 per cent SiO2, 13.12 per cent Al2O3, 16.00 per cent CaO and 14.00 per cent MgO showed that the spinel solid solution (M3O4) was the primary phase until a pO2 of 10-10.5 atm, thereafter M3O5 was the primary phase until a pO2 10-13.2 atm. M3O4 again was the primary phase between a pO2 10-13.2 and 10-16 atm. The changeover of the primary phase coincided with an increase in the liquidus surface. When cooling the slag in a pO2 of 10-16 atm, M3O5 crystallised as a ternary phase that showed a rapid increase in mass while that of the primary M3O4 phase decreased and that of the secondary perovskite (CaTiO3) phase increased at a slower rate. At 1300°C under sub-liquidus conditions, the contents of M3O5, M3O4 and CaTiO3 were about 20 per cent, 15 per cent, and 11 per cent, respectively. Experimental results showed that the Ti3+/Ti4+ mass ratio in the M3O5 phase, ie a measure of the reduction of titanium species, is not considerably sensitive to equilibration temperature in the reviewed range. Slow cooling and minimum/no oxidation during cooling of titaniferous slag would increase the deportment of titanium species to, and the growth and stability of the M3O5 phase.

Jun 19, 2024

Characterisation of Computer Printed Circuit Boards for Hazardous Properties and Beneficiation Studies

Sep 13, 2010

By David E. Siskind

The Bureau of Mines studied airblast from surface mining to assess its damage and annoyance potential, and to determine safe levels and appropriate measurement techniques. Research results obtained from direct measurements of airblast-produced structure responses, damage, and analysis of instrument characteristics were combined with studies of sonic booms and human response to transient overpressures. Safe levels of airblast were found to be 134 dBL (0.1 Hz), 133 dBL (2 Hz), 129 dBL (6 Hz), and 105 dB C-slow. These four air-blast levels and measurement methods are equivalent in terms of structure response, and anyone could be used as a safe-level criterion. Of the four methods, only the 0.1-Hz high-pass linear method accurately measures the total airblast energy present; however, the other three were found to adequately quantify the structure response and also represent techniques that are readily available to industry. Where a single airblast measuring system must he used, the 2-Hz linear peak response is the best overall compromise. The human response and annoyance problem from airblast is probably caused primarily by wall rattling and the resulting secondary noises. Although these will not entirely be precluded by the recommended levels, they are low enough to preclude damage to residential structures and any possible human injury over the long term.

Jan 1, 1980

By G. H. Glos

There was a time when an occasional failure of a tailings embankment was considered an acceptable risk associated with mining activities. This is not the case anymore. A major tailings failure today could result in the indictment of mine officials, huge fines and a possible site closure due to the loss of operating permits. As a result of this changed operational environment, tailings disposal facilities must be operated with these potential consequences in mind. Physical controls for tailings embankments are prohibitively expensive. However, the nuclear industry has developed a system of administrative controls as an alternative to physical controls. Administrative controls may be defined as control of actions, through organizations and management, using written procedures, record keeping, review and audit to assure operation of a facility in a safe manner (10 CFR 50). Administrative controls can reduce the cost of operating tailings impoundments, as well as increase the level of confidence in these facilities.

Jan 1, 1999

The relationship between the maceral composition of coal and the strength of the coke produced from that coal has received a great deal of attention in recent years.Studies using two Bulli Seam coals, and blends of Bulli and Wongawilli Seam coals, from the IIIawarra Measures of the Southern Coalfield of New South Wales were carried out.The optimum range of vitrinite was found to lie between 45 per cent and 60 per cent (mineral matter free).Above and below this vitrinite range coke strength deteriorated. Coke strength indices increased with rank, and the optimum vitrinite content increased with an increase in rank. These changes require confirmation as trends by testing a third level of rank. It was noted that vitrinite content decreased with an increase in the specific gravity of separation of the coal.Use of petrographic analyses will increase confidence in choosing coals for coking, provided the coals are well known. Such analyses offer the possibility of greater flexibility in coal purchases and the possibility of producing a marketable blend from coals, which have limited market potential. Critical base coals for blends can be conserved.Significantly more work is required before coal reserves can be utilized to optimum advantage. This work would require extension of the studies discussed in this paper and, in particular, the testing of a wider range of rank.

Jan 1, 1971

By G A. Wellwood

What do all iron ore mines have in common? Perfect production days! Yes, those harmonious 24-hour periods when the stars align and the daily output number rockets past the long-term average to hit new heights. While perfect days are always welcome, the focusing question iswas that just a ‘flash in the pan’ (due to a special cause) or an indication of the process’s capability (with clues to the common causes) which, if addressed, could make every day perfect? In the context of today’s operating environment, with the need to maximise productivity at minimum cost, it’s an important question.Investigations reveal that the throughput difference between a perfect production day and the average is often in the order of 40 per cent, and that bulk solids handling (BSH) system deficiencies are the largest (>50 per cent) class of lost opportunity. Root causes for underperformance of elements in BSH systems can often be traced back to the detailed design and even study-stage oversights. Essentially baked into the fabricated plant, operations are effectively forced to accept them at the point of practical completion and then deal with the consequences for the life of the mine. Subsequent normalisation of these defects in the planning process reduces visibility and hence the impetus for long-term solutions in favour of lower targets and quick fixes to keep the show on the road. On an industry wide basis the design processes and assumptions responsible for BSH system underperformance become enshrined as common practice and hence repeated across sites and organisations.In addition to making the case for action, practical steps that can be taken to help realise the significant productivity prize and avoid the problems in first place are provided.CITATION:Wellwood, G A, 2017. One perfect (production) day – a bulk solids handling perspective, in Proceedings Iron Ore 2017, pp 443–452 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By F. D. Richardson

STAFF: Editor, Gerhard Derge Carnegie lnstitute of Technology Schenley Park Pittsburgh, Pa. 15213 Editorial Assistant, M. A. Redmerski Production Editor, Otto T. Johnson THE METALLURGICAL SOCIETY: Jack H. Scoff, President; Richard C. Cole, Past-President; Harold 0. Emerick, President-Elect; Ralph L. Hennebach, Treasurer; Robert W. Shearman, Secretary; Donald A. Parks, Assistant Secretary; Leslie S. Wilcoxson, Assistant Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: R. E. Lund, Chairman; T. E. Dancy, H. O. Emerick, P. R. Gouwens, R. E. Grace, J. H. Jackson, H. H. Johnson, A. E. Lee, Jr., R. R. Nosh, R. D. Pehlke, and Paul Queneau. Review and selection of manuscripts is under the supervision of the following Publications Committees: Extroctive Metallurgy Division: R. E. Grace, Choirmon; G. M. Bell, D. W. Bridges, J. M. Cigon, G. W. Heoly, T. A. Henrie, R. D. (Holli-doy, C. E. O'Neill, C. S. Somis, A. W. Schlech-ten, and Charles Shull. Iron and Steel Division: R. D. Pehlke, Choirmon; T. P. Floridis, Arnulf Muon, G. R. St. Pierre, E. T. Turkdogan, L. H.Von Vlock, and J. M. Uys. lnstitute of Metals Division: H. H. Johnson, Jr., Chairman; J. B. Clark, Vice Choirmon; M. R. Achter, G. F. Bolling. J. O. Brittoin, G. P. Conard, II, R. S. Davis, L. A. Girifolco, G. T. Hohn, J. P. Hirth, L. Himmel, G.T.horn, George Krauss, J. D. Livingston, R. D. Manning, H. M. Otte, S. V. Rodcliffe, R. E. Reed-Hill, H. C. Rogers, E. ScaIa, O. Sherby, M. T. Simnad, G. R. Speich, E. A. Steigerwald, R. A. Swolin, W. A. Tiller, W. R. Upthegrove, J. B. Wagner, Jr., Derek Wolton, H. W. Weart, W. W. Webb, and D. Published seven times yearly in February, March, April, June, August, October, and December by the American lnstitute of Mining, Metallurgical, and Petroleum Engineers, Inc., 345 East 47th Street New York, N. Y. 10017. Telephone PLAZA 2 -6800. Subscription $30 per year for non-AtME members m United States and North, South, and Central America; $32, foreign; $7.50 for AlME members Single copies, $6.00, single copier foreign, $6.50. The AiME is not responsible for any statement made or opinion expressed in its publications . . . Copyright 1964 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address, AiME New York Indexed in Engineering Index, Industrial Arts Index, and Chemical Abstracts. Second dost postaas poid ot New York, N. Y.,ond Ann Arbor, Mich. Volume 230, Number 6.

Jan 1, 1964

By Garland E. Likins

High-strain dynamic testing of drilled shafts and cast-in-place piles has become routine procedure in many parts of the world today. Field testing is performed by measuring strain and acceleration records under impact of a falling mass. Wave equation analysis is utilized to design the weight, drop height and cushion of the hammer apparatus to assure a successful test. The Pile Driving Analyzer* (PDA) and CAPWAP* methods are used for data acquisition and analysis. Testing results yield information regarding pile static bearing capacity, structural integrity, and pile-soil load transfer and pile load-movement relationships. This paper discusses application of high-strain dynamic testing to cast-in-place shafts with emphasis on aspects unique to this type of pile. Suggestions regarding minimum requirements for good quality tests are offered. Five case histories reported in the literature are summarized and a sample specification is also included.

Jan 1, 1995