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By W. S. Weldon, R. M. G. Machunter

The use of spiral separators for the beneficiation of fine coal typically in the size range - 2+0.lmm is now well established process technology. Developments during the mid 1980's resulted in the production of cost effective, efficient large diameter coal spiral separators. Recent developments and research have been geared to optimise metallurgical performance, materials handling and equipment geometry of large diameter coal spiral separators.

Feb 24, 1997

By U. K. Custred

In 1973, the United States production of marketable phosphate rock set a record in excess of 42 million tons. This production rate is expected to continue to increase, due to the growing international requirement for fertilizer, at a rate exceeding 5% per year well into 1977. This trend contrasts sharply with the reduced phosphate rock production levels of the 1966 - 1971 period. The natural consequence of this growing phosphate rock market is an evaluation of the variety of means whereby plant capacity can be most effectively increased. One approach toward increased plant production capacity is through large capacity flotation cells provided they can be successfully applied to the recovery of the relatively coarse product which is characteristic of the phosphate rock feed. This paper will summarize the results of a nine month evaluation test program, conducted at the Haynesworth Mine at Bradley, Florida in which the flotation circuit "specific capacity" (tons feed/ft.2 floor space) and "specific input power" (Hp/ton feed) were determined, and the feasibility of achieving economically acceptable concentrate grade and recovery levels was demonstrated, using large, high capacity, flotation cells.

Jan 1, 1974

By U. K. Custred, E. W. Long, V. R. Degner

In 1973, the United States production of marketable phosphate rock set a record in excess of 42 million tons. This production rate is expected to continue to increase, due to the growing international requirement for fertilizer, at a rate exceeding 5% per year well into 1977. One approach towards increasing plant production capacity to meet the growing demand is through large-capacity flotation cells, provided they achieve metallurgical performance comparable to existing smaller cells. A 9-month evaluation test program recently completed at the Haynsworth mine at Bradley, Fla., demonstrated the feasibility of achieving economically acceptable concentrate grade and recovery levels using large, high-capacity flotation cells. The composition of the feed to the Haynsworth beneficiation plant is a typical Florida pebble phosphate matrix composed of phosphorite pebbles ranging in size from approximately 1-1/2 in. down to 150 mesh and intimately associated with a mixture of clay and sand (essentially silica). The feed contains approximately 22 to 28% phosphate reporting as tricalcium phosphate, Ca3 (PO,) 2, or "bone phosphate of lime" (BPL). The flotation section utilizes the double-float procedure typical of Florida plants. The phosphate is first floated away from the silica in the rougher circuit, using crude fatty acid, ammonia, and fuel oil or kerosene. Rougher conditioning is accomplished at 60 to 70% pulp solids with sufficient ammonia added to raise the pH to 9 to 9.5. Following coarse and fine rougher flotation, the concentrate (overflow) streams are joined and conditioned (sulfuric acid cleaned and washed) prior to entering the cleaner circuit where an amine float (cationic reagent and kerosene added in the feed box; pH 7.3 to 7.8) is employed to float the silica. The feed to the coarse rougher circuit averages 29% +35 mesh while the fine rougher feed averages 10%+35 mesh. Primary attention was directed toward the large rougher cell performance (recovery and grade) on coarse feed during the Haynsworth evaluation program. Flotation Cell Test Program A row of three No. 120 size (300 cu ft) WEMCO flotation cells was installed in parallel with an existing air-cell row. The total installed volume of the large cell circuit was 900 cu ft and required a floor space of 306 sq ft. This compared to the air-cell total volume of 200 cu ft and 152 sq ft floor space. (Both floor areas include feed and tails hoppers but exclude walkways.) Fig. 1 is a schematic cross section of the large flotation cell showing the relative location of key mechanism elements. In operation, the rotor generates a fluid vortex extending up along the walls of the standpipe and creating a sufficient vacuum within its core to ingest air into the standpipe/rotor cavity through the air inlet duct. The ingested air mixes with the pulp, which has been recirculated through the false bottom and draft tube, in the rotor. Further mixing occurs as the air and pulp move radially outward from the rotor, finally passing through the disperser into the flotation cell. Flotation is accomplished outside the disperser, where phosphorite laden air bubbles rise and the remaining pulp recirculates down along the cell wall to the false bottom and draft tube. Large-flotation-cell performance is influenced by the ability of the mechanism to (1) circulate, or suspend, the solids in the pulp; (2) ingest air into the rotor cavity; and (3) mix the air and pulp effectively. The proper balance between pulp circulation and air ingestion is a key consideration in achieving good recovery in a course feed application. Large-flotation-cell pulp circulation and air transfer characteristics are significantly influenced by rotor speed and rotor submergence; therefore, these two operational parameters can be used to "optimize" a particular mill application. Fig. 2 maps the hydraulic performance of the WEMCO No. 120 size flotation cell. This map can be used to relate the cell operational parameters which influence metallurgical performance. At a given rotor speed, power intensity (i.e., pulp circulation) is seen to increase, and airflow decrease, as rotor submergence is increased. The inverse relation between power and airflow is due to the two-phase air-liquid mixture density reduction accompanying the increased airflow rate. For any fixed rotor submergence, the power intensity (i.e., fluid circulation) and airflow both increase as rotor speed is increased. The selection of these two mutually related operating conditions (i.e., rotor speed and submergence) was a key consideration in the Haynsworth evaluation program.

Jan 1, 1976

By P. Erskine

"Hyperaccumulator plants can be utilized as ‘metal crops’ in agromining operations. This emerging technology produces ‘bio-ore’ by growing ‘metal crops’ on sub-economic ore materials, such as natural ultramafic soils. In a typical application plant material is periodically harvested, followed by air-drying and incineration to produce the bio-ore intermediate. The bio-ore is of very high grade (>15 wt. % nickel), and of high purity, and may be processed into a number of different products (including nickel metal, nickelbased catalysts and pure nickel salts). Current research efforts from our team focus on Mediterranean climate field trials (Albania, Spain) and tropical climate field trials (Malaysia, Indonesia). Field-scale demonstrations are required to provide evidence of real-life performance and of economic viability. If the trials are successful, agromining may in the near future support local livelihoods with income opportunities as an alternative type of agriculture: to farm nickel.INTRODUCTION AND BACKGROUNDHyperaccumulators, plants with the exceptional ability to uptake and concentrate trace elements in their shoots, can be utilized as ‘metal crops’ in agromining operations (Van der Ent et al., 2013a; Chaney et al., 1998; 2007; Baker et al., 2010). Agromining produces ‘bio-ore’ from harvested ‘metal crops’ grown on unconventional resources such as natural ultramafic soils (Van der Ent et al., 2015a). The bio-ore is a high purity and very high-grade (>15 wt. % nickel) product intermediate that may be turned into a range of different nickel products (nickel metal, nickel-based catalysts and pure nickel salts). The potential for agromining is greatest in tropical regions (Asia-Pacific Region: Indonesia, Malaysia, Philippines, Papua New Guinea and New Caledonia) where very large expanses of ultramafic soils exist (Van der Ent et al., 2013b). Agromine operations may replace existing marginal agriculture on poor ultramafic soils, for example oil palm plantations that require high fertilizer inputs to be profitable, or take place under a cocropping regime. The ability of ‘metal crops’ to achieve high nickel concentrations in biomass (and hence in harvested bio-ore) from soils with just <0.5 wt. % nickel, makes it possible to access non-conventional resources, not accessible by traditional mining techniques. For example, agromining could be implemented both on the large ‘halo’ around the mine leases, and as part of the progressive rehabilitation process after conventional resource extraction. As with all methods for resource extraction, agromining will be finite due to the diminishing concentrations of nickel in the zone accessible by plant roots (Chaney et al., 2014). Nevertheless, considering soil materials with 0.2 wt. % nickel and ‘metal crops’ with a yield of 100 kg nickel ha-1 the agromining venture may be sustainable for decades (Van der Ent et al., 2015a)."

Jan 1, 2016

By James Paone

Drillability of rocks by mechanical means is closely related to the physical properties of the respective rocks, Various approaches by previous investigators on rock drillability are presented, as well as recent techniques studied by the Bureau of Mines. The studies show drillability concepts based on (1) theoretical drilling equations derived from laboratory drilling experiments extended to field drilling results and on (2) a statistical method where multiple regression analysis is used to develop a prediction equation for drillability.

Jan 1, 1966

By Andrew F. McKown, Lewis L. Oriard

Advances in explosives engineering are moving forward in several different aspects. These include improvements and new development in explosives products, the application of these products to blasting technologies, and the study of the peripheral effects of the use of explosives, such as ground vibrations and airblast. Topics of special interest in the last several years include new explosives and detonators, cap timing, explosive casting, high-speed photography, perimeter and slope control, air decking and mathematical modeling of blasting processes.

Jan 1, 1988

By AIME AIME

THE non-ferrous alloys have been placed in the same class with steel by metallurgical research on hardening, and hardenable alloys of all metals except zinc are now manufactured. The hardening of the non-ferrous alloys is accomplished by a process of heating, quenching and ageing. R. S. Dean, head of the research department of the Western Electric Co., told of the results of this research in &apos;a lecture on "Recent Advances in the Art and Science of Fabricating Metals," given before the Missouri Mining and Metallurgical Association on Jan. 24, 1929.

Jan 1, 1929

By Hans Lundberg

PREFACE THE successful conclusion of all geophysical work depends on the operator&apos;s skill and sound judgment, as well as on his knowledge of geology and geophysics. We have been fortunate enough to have as co-workers a number of very good men. Some results of their work are summarized in this paper, and it is a pleasure to acknowledge their cheerful spirit of co-operation and the enthusiasm and loyalty with which they have assisted in the building of a geophysical organization to serve the Canadian mining industry HISTORY Geophysical prospecting is commonly, but quite erroneously, regarded as something new. The name is modern, but the principle of applying physical laws to reveal the presence of hidden ore is several hundred years old. Already, at the beginning of our civilization, the need was strongly felt for methods that could indicate the presence of ore in regions where the ore-bodies were completely masked or hidden from the eye. Particularly in countries where the rocks have been eroded during periods of glaciation and later covered by a thick mantle of glacial debris, all kinds of mysterious schemes were invented to locate the hidden ore. Often magic was resorted to (for example, the divining rod), but methods based on sound principles were also developed. Such features as topography, colour and taste of surface waters, and the growth and occurrence of trees and plants, were used to reveal certain types of ore deposits. For finding bodies of iron ore, the compass was very early in use. The fact that objects of iron attract a compass needle was utilized in prospecting long bef01:e the time of Columbus, and a systematic search for bodies of iron ore by this method was organized as early as the year 1600. There are still in existence documents, dated a little over 300 years ago, which show that the Swedish Chancellor of that day, Axel Oxenstiorna, ordered dozens of sun-dial compasses from instrument makers in Germany. The Swedish Government at that time employed a great number of prospectors to search systematically for iron ore. This Government undertaking must have been quite successful, as a number of iron ore-bodies were found in areas covered by heavy overburden. These prospectors were simply Government &apos;geo-physicists&apos;, although they were not known by this fancy name.

Jan 1, 1937

This paper reviews recent advances in geophysical tools for mineral exploration. It does not restrict comments to methods which are usually applied in the tectonically active belt surrounding the Pacific Ocean, where geophysics has often been secondary to geological prospecting (eg visual recognition of surface alteration) and drainage geochemistry; but considers geophysical tools applied to a broader range of both deposits and terrains. For example, the subdued topography of much of Australia and Canada has lent itself to the development and extensive application of airborne methods. In Australia, deep weathering and transported cover have necessitated the use of geophysical methods to not only detect anomalies but also to map and understand basement geology. This same weathering has caused specific problems, particularly for electrical methods, but recent improvements in instrumentation, processing and visualisation have largely overcome them. A great deal of geophysical data is now being collected by government agencies, often from the air, and made readily available to explorers. In several Australian states it is free, often on line, and in almost all cases it is relatively cheap. These regional data sets are often augmented by more detailed local surveys in areas of interest. Although æanomaliesÆ are still important much more is being done with the high quality data which is now available The results are used for geological mapping, to test geological hypotheses, to construct detailed 3D geological models and, together with fluid flow modeling, to predict optimum locations for mineralisation.

Jan 1, 2004

By O Ishiyama, L Lu

Sintering is the most economic and widely used agglomeration process to prepare iron ore fines for blast furnace use. Due to the depleting reserves of traditional high-grade iron ore, there have been considerable changes in iron ore resources available throughout the world, especially in steel mills in East Asia. Corresponding to the changes in the availability of iron ore resources, the amount of impurities in iron ore has been slowly increasing. Some of these impurities have been found to have deleterious impacts on sinter quality and sintering performance. In the meantime, an increasing number of large blast furnaces with inner volumes of more than 5000 m3 have been built that require more sinter and are often more demanding in terms of the quality requirements of the ferrous materials. Finally, sinter plants are facing increasing pressure due to more stringent regulations regarding their environmental impact. This paper gives an overall review of a variety of technologies developed worldwide to tackle the changing raw material characteristics and mitigate emissions from sintering operations.CITATION:Lu, L and Ishiyama, O, 2015. Recent advances in iron ore sintering, in Proceedings Iron Ore 2015, pp 61–68 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Charles Reed

WITH the increasing importance of clay in drilling operations which demand more precise and exacting control over its behavior, there has come the realization that most of our present methods of control over many of its important properties still represent more of an art than a science. Such a situation with respect to a material of such industrial significance is unfortunate, and naturally many investigations have been conducted to improve our knowledge. In general, these investigations have revealed the complex nature of clay behavior and while sometimes they may not have seemed to contribute directly to a solution of the field operator&apos;s problems they have been of inestimable importance in bringing to light the broad fundamental scientific principles upon which must be based any effective working theory correlating the known facts of clay behavior and predicting profitable new lines of attack for its improvement.

Jan 1, 1938

By Benoit Virollet

Over the last 10 years the diameter of unbraced, unlined and unanchored circular shafts has grown dramatically in many parts of the world. This progress has taken place through improvements in: construction methods; concrete rheology; and design capabilities. Excavation equipment has become more precise in terms of operator control and ability to correct alignment of digging elements leading to better alignment tolerances. Also contributing to the increases in shaft diameters is the evolution of design models. A better understanding of soil structure interaction is being incorporated into the analyses in terms of radial soil stresses and imposed loads on the shaft. This paper provides an overview of the recent progress made in circular shaft construction, the primary design considerations, and some innovative uses of efficient arc elements to develop unsupported structures of other shapes. In addition, a summary of recent circular shafts constructed worldwide is provided.

Jan 1, 2006

By J. T. Ryan

SAFETY practice or the elimination of accidents in our coal mines is specifically a problem of management. It cannot be delegated to any governmental agency except that the various coal-producing states do and should have some minimum safety standard laws. However, the legislative method of attempting to control mine accidents is ineffective because of the delay between the necessity and the action. It will always be impossible to keep our various state mining laws up to date; and when the law says you must do a certain thin there is a tendency to do this and no more. Unless the scheme for setting up state regulations is so flexible that when a new hazard develops it can be immediately and adequately covered and the whole responsibility for accident elimination placed undivided on the

Jan 1, 1937

By Moto Goto

Today, Pierce-Smith converters, coupled together with various types of smelting units, are used in most of the world&apos;s smelters. However, due to the "batch" processing nature, and problems associated with fugitive emissions during the transfer of melt and blowing stages, this arrangement will unlikely be adopted in future smelters. Modern day alternative processes include the Mitsubishi Process, Outokumpu Flash Smelting and Flash Converting Process, the Noranda Process, and the Ausmelt Process, but only the Mitsubishi Process is a "truly continuous" smelting and converting operation, producing a constant flow of blister without tapping, and is economically proven by long term commercial operations. This paper reviews recent advances in modern continuous converting technologies, with a special section devoted to operation of the "first standalone Mitsubishi C-furnace" coupled together with a Noranda Reactor, at Port Kembla Copper Pty. Ltd. in Australia.

Jan 1, 2003

By Moto Goto

Today, Pierce-Smith converters, coupled together with various types of smelting units, are used in most of the world&apos;s smelters, However, due to the "batch" processing nature, and problems associated with fugitive emissions during the transfer of melt and blowing stages, this arrangement will unlikely be adopted in future smelters. Modern day alternative processes include the Mitsubishi Process, Outokumpu Flash Smelting and Flash Converting Process, the Noranda Process, and the Ausmelt Process, but only the Mitsubishi Process is a "truly continuous" smelting and converting operation, producing a constant flow of blister without tapping, and is economically proven by long term commercial operations. This paper reviews recent advances in modern continuous converting technologies, with a special section devoted to operation of the "first standalone Mitsubishi C-furnace" coupled together with a Noranda Reactor, at Port Kembla Copper Pty, Ltd. in Australia.

Jan 1, 2003

By R H. Sillitoe

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Geological concepts are employed routinely in porphyry copper exploration at the area selection, prospect appraisal and deposit definition stages. Regional, district-scale, deposit-scale and laboratory-based concepts can all play a role, with the resulting porphyry copper models providing templates for the integration of geochemical and geophysical responses and interpretations. Of the 19 concepts and parameters selected for brief discussion, those relating to subdivision of porphyry intrusions, understanding of diverse and commonly complex alteration-mineralisation patterns and lithocap characterisation are undoubtedly the most influential in exploration. Several of them are of particular importance because of their role in promoting grade development. Additional belt-, district- and deposit-scale features are currently little used but hold promise, whereas others have less practical value but help in underpinning the evolving porphyry copper genetic model.CITATION:Sillitoe, R H, 2015. Recent advances in porphyry copper geology and their exploration utility , in Proceedings PACRIM 2015 Congress, pp 35–44 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By G. J. Hutchins

Precision surface mining is gaining traction in the iron ore, copper, iodine, limestone, bauxite, coal and gypsum markets. In this paper, we first address the possible improvements of a surface miner control using GPS techniques. An application in an iron ore mine in Western Australia is presented. The second item addressed is improvements of a new drum driving technique for a 100 ton surface miner. This technique involves installing a slow speed hydrostatic motor directly on the cutting drum rather than driving the drum through chain and sprockets. Details of the performance of this direct-drive versus the chain-drive are detailed. In addition to the 100 ton machine, we also present a 200 ton surface miner. This larger machine has 1600 hp (894.8 kg), and has been successfully introduced into a large iron ore mine in Western Australia. Performance of the 200 ton surface mining machine in various rock hardnesses is detailed. Some comments on the cost effectiveness of using a built-in loader versus loading with wheel loaders are included.

Aug 1, 2013

By R. K. Filip

"Steel bearing piles have long been used to carry high compressive, tensile and lateral loads. Such piles are most commonly tubular or ""H"" profile and are typically installed using percussive techniques. The noise and vibration associated with such installation techniques tends to preclude the use of steel bearing piles in urban and other sensitive areas.This paper describes the design and construction of an innovative new road bridge in Milton Keynes, UK. The steel bearing piles were required to continue out of the ground to form the bridge columns and abutments and then be cast directly into the soffit of the reinforced concrete bridge deck. This project was to be the first time in the UK, that this form of bridge design had been used.The paper shows how new installation techniques allowed the designers to use these high capacity steel elements in a sensitive urban environment without the use of percussive or vibratory installation techniques. Finally the paper shows how these quiet and vibration-less installation techniques can be extended to other applications.A UNIQUE BRIDGE SUPPORTED ON ""BOXED SHEET PILES""CONCEPT HISTORYThere are over 700 bridges in Milton Keynes. Concrete is the dominant construction material, most are single span with massive parallel wing wall retaining abutments. All have a certain uniformity of aesthetic design. Pell Frischmann Consultants Ltd (PFC) proposed to the client, English Partnerships (EP), that an ""integral bridge"" with a slender open appearance would be an appropriate aesthetic form for a new highways bridge, within the district of Westcroft (figure 1). The concept required that the bearing piles be continued up out of the ground to form the bridge columns and abutments. Four rows with four piles in each row were suggested. Each would then be cast directly into the reinforced concrete bridge deck forming a moment connection (figure 2). This concept meant that a single continuous steel structural member would replace traditional reinforced concrete bored piles, pile caps and piers. This member would carry vertical and lateral loads. The conceptual design was intended to meet the following client requirements:"

Jan 1, 2005

By Ray. K. Filip

The concept of installing a steel sheet pile retaining wall into the ground by "pressing" has resulted in the development of various equipment solutions over the last thirty years e.g. Taylor Woodrow ?Pile Master&apos;, Giken &apos;Silent Piler" & Tosa &apos;Still Worker?. Dawson Construction Plant Ltd (DCP), have recently advanced the pile pressing concept with the introduction of their &apos;Push-Pull&apos; system. This advancement offers significant improvements in the quality of installation compared with traditional pressing solutions but also greater versatility, higher productivity and, most importantly, generates new opportunities through a wider range of applications for "silent piling&apos;. This paper will focus primarily on the use of the Push-Pull concept in the construction of a unique "integral" bridge in Milton Keynes, England. Finally, the paper touches on the development of quiet, vibration-less pile extraction equipment, which allows steel to be considered the foundation material of choice for truly sustainable construction. It is no longer acceptable to leave unwanted piles in the ground.

Jan 1, 2006

By V. G. Papangelakis, G. P. Demopoulos

"Recovery of gold from refractory ores and concentrates presently constitutes one of the most important, challenging, and exciting areas of R&D activity in the gold processing industry. New technologies are being tested for the treatment of refractory gold materials, some of which have been advanced to the level of commercial operation. In this paper, some recent technological developments in the hydrometallurgical processing of pyritic matrix-refractory gold ores are highlighted. Key operational steps of each of the alternate hydrometallurgical technologies are analyzed and potential advantages and drawbacks are identified. The processes which are reviewed are: hydro chemical oxidation, biochemical oxidation and pressure oxidation. INTRODUCTIONOver the years the term ""refractory"" has been applied in gold ore processing to denote situations in which straightforward cyanidation failed to yield high gold recoveries. A number of mineralogical and chemical factors may be responsible for this ""refractoriness"" problem. A systematic classification of the different options for their treatment has been discussed in a recent review paper. In this paper, the pretreatment of the submicroscopic gold encapsulated within the matrix of pyrite and arsenopyrite minerals is considered. This type of gold is the ultimate refractory material because complete breakdown by reaction of the host mineral structure is required.The method which has been traditionally applied for the treatment of pyritic-type refractory gold ores is an oxidation roast (single stage or double stage depending on the As content) of a flotation concentrate to produce a porous calcine, the latter being more amenable to cyanidation. Despite its established practice, oxidation roasting is not considered particularly attractive with today&apos;s standards for high product recovery and clean environment. Roasting is known to be very sensitive to heating parameters and feed composition and deviation from optimum conditions can result in reduction in permeability which is translated to incomplete gold liberation."

Jan 1, 1989