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By Robert L. Sundeen, Richard V. Wenberg

INTRODUCTION Shotcrete can be defined as spray-applied concrete with a maximum size aggregate in excess of 9.5 mm (0.375 in.). The concept evolved from guniting, which uses smaller aggregate and generally produces concrete with poorer physical properties. The larger aggregate used in shotcrete requires less water in the mix, while offering larger bonding surfaces, thus imparting greater tensile and compressive strengths. TYPES OF MACHINES Two basic designs of shotcrete machines in general use are the wet or prehydrated zero slump and low slump type, and the dry or nozzle hydrated machines. Fig. 1 shows a typical zero-slump machine in a con¬figuration commonly used for small-volume require¬ments. The prehydrated zero-slump machine mixes exactly proportioned batches in a sealed pressurized chamber. "Slugs" of hydrated shotcrete mix and com¬pressed air are sent through a distribution hose to the nozzle where the wet mix emerges as a spray. The spray is directed onto the rock surface by the nozzle operator. The low-slump machine is similar, except that a thick slurry mix of aggregate is delivered throughout the distribution hose to the nozzle. Fig. 2 shows a typical low-slump shotcrete machine used in moderate-volume applications. The nozzle-hydrated shotcrete machine accepts a premixed "dry" (4 to 6% moisture) batch of aggregate and cement. A constant feed of this mix is directed by compressed air through the distribution hose to the nozzle. At the nozzle, water for hydration is introduced into the emerging spray. The hydrated mixture is di¬rected onto the rock surface by the nozzle operator. Fig. 3 shows a typical dry-mix machine. The major difference between the two basic machine designs is the consistency of the shotcrete quality. Pre¬hydrated machines have high degrees of consistency and produce high-strength concrete, resulting from their ability to produce exact mixtures of zero or low-slump concrete within the machine. Nozzle-hydrated machines tend to produce poorer quality concrete because of the difficulty in controlling the water content at the nozzle. Water input essentially is an art. As such it is not precise, and the shotcrete produced is of variable quality. MATERIALS HANDLING Materials handling presents a problem to either type of shotcrete machine. At times considerable quantities

Jan 1, 1982

During the last 20 years, manufacturers of Australian iron have given increasing attention to development of external markets for processed blast furnace slag. Slag has been in widespread use overseas and data on the performance of Australian slag in concrete lave shown it is suitable for that use. Chemical and physical properties of typical Australian slag products including air cooled, granulated and pelletised slag are discussed and compared with local natural aggregates. Special attention is given to pumping achieve- ments with slag concretes and the observed durability of concrete after many years service. More'recent applications for granulated slag as a sand replacement are discussed. It is concluded that'whilst more wide- spread use of slag is possible, the cost of marketing and transporting slag are likely to restrict opportunities unless for local usage.

Jan 1, 1979

By Chas. F. Jackson

The work of the Mining Division is divided among seven sections, each in charge of a supervising engineer, as follows: 1. Metal-mining methods section, the supervising engineer of which is also supervising engineer of the Southwest Experiment Station at Tucson, Ariz. 2. Metal-mining research section. 3. Nonmetal-mining section. 4. Coal-mining section. 5. Mine-ventilation section. 6. Mineral-industries survey section. 7. Electrical section. The names of the sections indicate broadly the fields covered by each, and in the following, pages the objectives and type of work of each section will be summarized briefly and their active problems listed. The work clone during the fiscal year 1937 will also be summarized.

Jan 1, 1937

By A. Patton

Introduction THE use of roll scale in the Bessemer process dates back, to the "best of our knowledge, at least 20 years. It was first used by the Ohio Steel Co.; Youngstown, Ohio (now the Ohio Works of the Carnegie Steel Co.) under the direction of Sam, MacDonald, Superintendent of the Bessemer Department at these works. Two 10-ton vessels and one blowing engine capable of blowing one heat at a time were employed. The object of using the scale was to -shorten the length of the blow; or in other words, to increase the production with the same equipment. Various means were tried out for introducing the roll scale into the bath of molten iron: It was shoveled into the vessel before the heat was charged, so that the metal would flow over the scale; it was shoveled into the bath after the vessel was turned up; it Was dumped into the empty iron ladle by the wheelbarrow-load, and at times wars dumped on top of the molten metal in the iron ladle. But the practice of introducing the scale into the iron ladle had to be abandoned on account of danger from explosions and of skulling the -ladles. It was soon learned that the proper place to charge the scale was in the empty vessel, so that when the molten iron was poured into the vessel it flowed over the scale, causing a considerable reaction to take place before the heat was turned up. Eventually, cylindrical chutes similar to those now in use were installed. Into these chutes the scale is dumped and carried into the empty vessel. Before this convenient means of introducing the scale was adopted, the Ohio Works had satisfactorily demonstrated that roll scale would increase production, by blowing 107 heats in one 12-hr. turn (1,087 tons) with one blowing engine, blowing one heat at a time; whereas, prior to the use of scale, the best practice at these works was about 80 heats under the same conditions.

Jan 2, 1917

By Charles L. Ross

A successful placer mine is being operated by the E. T. Fisher Co. on Rock Creek in the South Pass mining district at Atlantic City, Wyo. About 2,800 cubic yards of gravel is dug daily by a gasoline-driven dragline shovel with a 1 1/4-yard bucket and washed in a movable plant with a gold-dredge trommel and standard-dredge sluice boxes; the total cost is about 12 cents per cubic yard. The gold-bearing gravel occupies a narrow valley between two low ranges, of hills. The ground is covered by brush and willows, which are cleared of in the fall by burning after the leaves have dried. The elevation at the mine is 7,600 feet above sea level.

Jan 1, 1935

By Edward Sampson, Allan B. Griggs

Surveying of many holes drilled by the U. S. Bureau of Mines in the Metaline district has shown surprising deviations. The holes start in the Ledbetter slate (Ordovician) and pass into the underlying gently dipping Metaline limestone (Cambrian) at varying depths, locally in excess of 1000 it. All holes start vertical, but one had deflected as much as 35° at a depth of only 300 it. One hole was found to be deflected 70' at a depth of 1000 ft. These deviations were not indicated to the drillers by any action of the rods or machines. Analysis of the survey data in the light of the observed geology indicates that the holes deviate most in the Ledbetter slate and scarcely at all in the Metaline limestone. The upper part of the "limestone'" in most holes is a massive rock strongly altered by hydrothermal action and essentially homogeneous. The slate is only obscurely bedded but has a cleavage, varying from slight to strong, which is unrelated to bedding. Drill holes have deflected to become nearly perpendicular to the cleavage. Several plans and cross sections are submitted showing the behavior of various holes. Introduction The Metaline district of northeastern Washington has received much attention recently and has promise of becoming even more important as a source of zinc than at present. Exploration has been conducted largely by deep diamond drilling, and in the course of this work it was found that holes became seriously deflected. This paper deals with the nature and causes of these deflections. The district lies along the Pend Oreille River in the northeastern corner of Washington, about loo miles north of Spokane, 9 miles from British Columbia, and 15 miles from Idaho. Three mines are now in operation and for a number of years have furnished a considerable production of zinc and lead. The ore contains zinc and lead in a ratio of about 31/2 to I, and occurs in the upper part of the Metaline limestone of Cambrian age, the upper member of which, where unaltered, is a rather pure limestone. This is overlain by Ledbetter slate of Ordovician age. Ore has formed by replacement of limestone, commonly 100 to 200 ft. below the slate, in areas of gentle dip, resulting in extensive tabular ore bodies. In and near ore, limestone has been intensely altered to granular dolomite and fine-grained quartz, which, where it predominates, forms "jasperoid." As part of their war program, the Geological survey and Bureau of Mines of the U. S. Department of Interior have been cooperating in an investigation of the district. The exploration by the Bureau of Mines in 1943 and 1944 was conducted largely by deep diamond drilling in which as much as 1000 ft. or more of Ledbetter slate was penetrated before the ore-bearing Metalin-2 limestone was reached. During the course of this drilling it was found that holes were seriously deflected while traversing the Ledbetter slate.

Jan 1, 1949

By Edward Sampson, Allan B. Griggs

Surveying of many holes drilled by the U. S. Bureau of Mines in the Metaline district has shown surprising deviations. The holes start in the Ledbetter slate (Ordovician) and pass into the underlying gently dipping Metaline limestone (Cambrian) at varying depths, locally in excess of 1000 it. All holes start vertical, but one had deflected as much as 35° at a depth of only 300 it. One hole was found to be deflected 70' at a depth of 1000 ft. These deviations were not indicated to the drillers by any action of the rods or machines. Analysis of the survey data in the light of the observed geology indicates that the holes deviate most in the Ledbetter slate and scarcely at all in the Metaline limestone. The upper part of the "limestone'" in most holes is a massive rock strongly altered by hydrothermal action and essentially homogeneous. The slate is only obscurely bedded but has a cleavage, varying from slight to strong, which is unrelated to bedding. Drill holes have deflected to become nearly perpendicular to the cleavage. Several plans and cross sections are submitted showing the behavior of various holes. Introduction The Metaline district of northeastern Washington has received much attention recently and has promise of becoming even more important as a source of zinc than at present. Exploration has been conducted largely by deep diamond drilling, and in the course of this work it was found that holes became seriously deflected. This paper deals with the nature and causes of these deflections. The district lies along the Pend Oreille River in the northeastern corner of Washington, about loo miles north of Spokane, 9 miles from British Columbia, and 15 miles from Idaho. Three mines are now in operation and for a number of years have furnished a considerable production of zinc and lead. The ore contains zinc and lead in a ratio of about 31/2 to I, and occurs in the upper part of the Metaline limestone of Cambrian age, the upper member of which, where unaltered, is a rather pure limestone. This is overlain by Ledbetter slate of Ordovician age. Ore has formed by replacement of limestone, commonly 100 to 200 ft. below the slate, in areas of gentle dip, resulting in extensive tabular ore bodies. In and near ore, limestone has been intensely altered to granular dolomite and fine-grained quartz, which, where it predominates, forms "jasperoid." As part of their war program, the Geological survey and Bureau of Mines of the U. S. Department of Interior have been cooperating in an investigation of the district. The exploration by the Bureau of Mines in 1943 and 1944 was conducted largely by deep diamond drilling in which as much as 1000 ft. or more of Ledbetter slate was penetrated before the ore-bearing Metalin-2 limestone was reached. During the course of this drilling it was found that holes were seriously deflected while traversing the Ledbetter slate.

Jan 1, 1949

By André G. Journel

Geological study of the Prony Nilaterite (New Caledonia) began in 1969 and included drilling, geological mapping and laboratory studies. The deposit is the product of weathering of basic rocks. From top to bottom, the following zones can be distinguished: a compact ferruginous cover; ore associated with yellow laterite, containing 1.0-1.5% Ni and low in impurities (SiO2, Mg); an intermediate silicated ore containing 1.3-2.0% Ni and higher percentages of impurities; garnierite ore much richer in nickel (2-4%) but high in SiO, and Mg contents (Mg up to 20%) ; and parent rock, largely peridotites. Distinction between types of ore is essential because the high grade ore (silicated and granierites) is penalized for its high Mg contents that demand additional acid treatment. All studies made distinguish two types of ore, laterite and silicated.

Jan 10, 1973

By M G. Aylmore, L W. de Klerk

Roasting of refractory gold ores has been a commercial process for many years. Improvements in design of fluidised bed roasting technologies and low capital and operating costs compared with other refractory treatment processes can potentially make roasting a viable option.However, gold extraction from roasted ores carried out on laboratory scale equipment often invariably yields lower recoveries than other processes such as bio-oxidation or pressure oxidation. Non-optimal laboratory roasting conditions can incorrectly write roasting off as a process option.Low gold recoveries from the cyanidation of calcine products from roasting can often be attributed to roasting conditions not favouring gold liberation and agglomeration processes, particularly if lockups of elements such as arsenic are being pursued for environmental reasons.This paper reviews the conditions favoured for gold agglomeration and accessibility of gold to cyanide, test conditions to achieve gold liberation and agglomeration on laboratory scale and designs that incorporate staged decomposition and roasting to make roasting a more commercial option.CITATION:Aylmore, M G and de Klerk, L W, 2013. Conditions and design considerations for maximising recoverable gold in roasting of refractory gold ores, in Proceedings World Gold 2013 , pp 375-388 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By M. K. Gangal, E. D. Dainty

The CANMET diesel-related work, carried out in cooperation with the Canadian mining industry, resulted in the identification of several useful R/D studies. One such study was the development of a dash-mounted alarm signal system to indicate overexposure of production LHD diesel vehicle operators to toxic contaminants in a mine environment. The resulting instrument has been called the [CO2 Exposure Meter]. This meter is particularly applicable to LHD machines because previous investigations have indicated that operators of LHDs and some haulage truck drivers are exposed to up to 200% of the contaminant concentrations measured in the general mine return air. This paper describes the development of the system which continuously monitors and displays the operator's exposure to diesel pollutants, and indicates an overexposure by an alarm light. The overexposure limits are preset by mine personnel based on carbon dioxide (CO2) measurements, which in turn are related to simultaneous spot respirable combustible dust (RCD) measurements (or to Air Quality Indices - AQI, if available). The CO2 settings are, in general, related to the engine/exhaust treatment selections, vehicle duty cycle and local ventilation rates and efficiency. The system continuously displays one of three lights: green for underexposure, yellow for caution, and red for overexposure. Overexposure can occur for several reasons, such as: reduced ventilation, malfunction of the diesel vehicle, and excessive airborne contaminants. The paper confirms satisfactory operation of the system in a laboratory-simulated mine environment, as well as in field trials.

Jan 1, 1993

By G J. A Dewar

The Australian Corporations Law generally requires Independent Expert Reports to be presented in support of capital raising or in defence of mergers and takeovers. The introduction of the VALMIN Code in 1995 (and its recent revision issued as the VALMIN Code, 1998) made Assessment and Valuation Reports in these circumstances much more comprehensible than before because of its key requirements for transparency and materiality. By forcing the Independent Valuer to provide an explanation of the reasoning behind the estimation of a particular resource asset, VALMIN allows the reader to clearly see any error or illogicality in the valuation methodology used and to seriously question or even reject the resulting value. Even though many elements of resource asset valuation practice are undeniably subjective, there must be some basis of objective rationality to it. Independent resource asset Valuers are the essential link between mineral explorers/miners on the one hand and brokers/analysts/fund managers/investors on the other. The minerals and financial industries both expect them to not use inappropriate or invalid valuation methods and illogical steps within these methods. This paper examines some of the less sensible ways in which some of the main techniques that Valuers commonly use to assess the fair market value of mineral properties have been applied in recent instances. The authors hope to discourage the adoption or perpetration of the æWhat-number-did-you-have-in-mind?' approach. It is MINVALÆs view that as many methods as possible should be used in any resource asset valuation. If any of the resulting estimates are in approximate agreement (particularly if they were derived using the less subjective of the available methods), ie if they cluster, they are probably more persuasive as being the Preferred Value of the asset than outlier values within the Valuation Range.

Jan 1, 1999

Cominco Ltd's Polaris Mine in Canada's High Arctic has been successfully mining zinc ore in permafrost since 1981. Mining methods using frozen backfill have been the key to success. The mine is now producing about 60 per cent of the ore from pillars while maintaining high productivities. Annual ore production is just over one million tonnes providing more than 200 000 tonnes of zinc concentrate each year. Cominco Ltd has adapted management and operating practices to suit the harsh environment and the isolated site, and has shown that a profitable development can be carried out in the tough Arctic conditions, with minimum impact on the environment.

Jan 1, 1993

By Sam S. Taylor, H. M. Smith

"INTRODUCTION In most oil fields, natural gas is the major source of energy causing flow of oil to the well. The amount of gas Produced with the oil generally exceeds actual energy requirements, so that in time the gas reserve of the field becomes seriously depleted and the oil production must be stimulated by some auxiliary means. One of these is to repressure the oil formation with natural gas; or, where a gas supply is not available, often air is used.Although P.ir is a Cheap and convenient repressuring medium, its use sometimes is attended with several disadvantages. First, the return air-gas mixture decreases rapidly in fuel value, often until it can be used no longer as a source of power. At the same time, explosive mixtures may result if recycling is used, causing hazards to life and equipment. Second, some fields experience considerable trouble with the formation of emulsions which become increasingly difficult to treat. Although there is no definite proof that air repressuring always causes these emulsions, many operators are convinced that this is the case. The Petroleum Experiment Station of the United States Bureau of Mines at Bartlesville, Okla., has been interested in problems connected with air-repressuring for a number of years. Some time was spent in studying the so-called ""bad gas""--return,mixture of low fuel value. However, it appeared impossible to attack the problem successfully from this angle, and an approach was made through a laboratory--scale study of direct oxidation of crude oil."

May 1, 1934

By W. Baguley, L. P. H. Greenhalgh, R. P. Riley

The traditional impeller system for aeration and suspension of slurries, e.g. in bacterial oxidation plants, is the vertical flat blade turbine (VFBT) . This type of impeller is energy-intensive, which results in a heavy-duty design of shaft, gearbox and drive. The Mixtec BX04 agitator development programme is designed to evaluate the use of the new generation of hydrofoil impellers which consume less power and thus have potential for capital and operating cost savings as well as being possibly less damaging to the bacteria. The early tests on pyrite oxidation in a 300 litre laboratory pilot tank using the Thiobacillus ferro oxidans bacteria, showed that hydrofoil impellers had superior characteristics to the VFBT impeller and to air-agitated pachucas, with lower energy input. The geometry of the air sparge ring was found to be very important in optimizing the system. These early successes resulted in a prototype impeller and sparge ring beinq tested in a 9m3 tank where oxygen uptake in water, impeller cavitation at different impeller speeds and air flows were evaluated. Resulting from this work was the supply of an agitator unit to an operating bacterial oxidation plant where it has been successfully evaluated. This paper describes the development work so far carried out

Jan 1, 1992

By V. H. Forsythe

Mr. Chairman, members of SME, and guests It is indeed a pleasure to have the opportunity to appear before this group. The topic of this paper is, "Current Trends in Related Industries and Their Influence on Electric Shovel Design and Size". Before getting into the major items, it is well to point out that this text will deal with loading shovels primarily, since their application is almost universal in major open pit mining operations throughout the world. Related industries influence our design in many ways. For the sake of simplicity, these industries will be broken down into two major categories. The first category to be discussed will include industries that will indirectly influence design and size, while the second category will include industries whose products can directly be incorporated by the engineer in the design of shovels.

Jan 1, 1964

By Nicholas T. Camicia

A career in the coal mining industry today offers students one of the most interesting and challenging opportunities available in the industrialized world. As reserves of other fossil fuels dwindle in face of the world's demand for energy, it has become apparent that coal, once the king of energy sources, must be relied upon again as the major fuel for powering industrial growth in developed and developing nations. Centuries of coal supplies lie beneath the earth's surface, assuring the world of a steady, plentiful supply of energy until science and technology can produce a way to harness and efficiently use renewable sources, such as solar. The need to increase our use of coal during the last two decades of the 20th century is reason enough to believe that the future growth of the coal industry is assured. A major impediment to that growth might be backward national public policies that could restrict the full utilization of our coal reserves. These policies could result from overregulation and a failure of the public to recognize that coal use, with proper techno- logical safeguards, is compatible with our society's environmental-quality objectives. Communication of this problem and its solution is a major undertaking of the coal industry in the 1980s. At the end of the 1970s, the American coal industry was producing approximately 635 Mt/a (700 million stpy) of coal. To meet the nation's projected energy needs by 1985, the annual tonnage must be doubled. A similar scenario is predicted for the rest of the world. Such growth in the modern international business world will require huge additional amounts of capital, equipment, and people who know how to wisely raise and apply the capital; use the equipment productively; and deal with the many community, public, and governmental problems such expansion will create. Whether a student's interest is in actual mining operations, business administration, engineering, finance, law, industrial relations, marketing

Jan 1, 1981

By Ali Soltani, Scott Santti

The Gold Quarry Mine is a large scale open pit mine located 11.3 km (7 miles) north of Carlin, Nevada. The operation consists of an open pit mine, two milling facilities, a leach crushing plant, and three dump leach pads. Gold Quarry is operated by Newmont Gold Company, which is 90.1% owned by Newmont Mining Corporation, a Denver based company. The property is the largest of the three gold producing properties operated by Newmont Gold Company on the famous Carlin Trend. This paper will give a general overview of the Gold Quarry mining facilities and detail mine operating practices. Specifics on cost saving ideas being implemented and those under investigation will be discussed.

Jan 1, 1989

By Edward Saibel

The various theories that have been advanced to explain or predict the conditions under which a metal fractures may be divided into two categories: First, there are the macroscopic theories generally used in engineering practice. These are empirical in nature and limited in application. For example, the maximum normal stress criterion, which is quite satisfactory for a mild steel in simple tension at atmospheric pressure,' no longer suffices when this steel is pulled under hydrostatic pressure.2 In all of these empirical theories, the critical condition characteristic of the material and of the loading conditions must be obtained experimentally. Secondly, there are the theories based on interatomic forces,3'4 or on the energy required to form new surfaces.5,6 These have all dealt with the theoretical evaluation of the tensile stress necessary to bring about rupture in a purely brittle manner; that is, without plastic flow preceding fracture. All of these attempts have led to values of the tensile strength of crystals or of polycrystalline bodies that are 100 to 1000 times higher than observed values. On this account, it has been thought necessary by some investigators to conceive of a microcrack structure or distribution of flaws throughout the specimen such that the resulting stress concentrations provide the factor necessary to bring about agree- ment between calculation and experiment. It has been pointed out by several observers' that this point of view is highly unrealistic, in that the weakening effect of these flaws or microstructures must be very uniform from specimen to specimen, since the fracture stresses found for various specimens of the same material tested under similar conditions are so nearly constant. Furthermore, since calculations based on atomic forces or atomic energy are for purely brittle fracture, a condition probably never satisfied in tests, agreement is hardly to be expected. Thermodynamic Theory of Fürth In order to resolve this apparent discrepancy between the theoretical cohesive strengths and the observed fracture strengths, Fürth8 advanced a thermodynamic theory of the tensile strength of isotropic bodies based on work of Born relating to the melting of crystals. Assuming an isotropic material free from imperfections and flaws, behaving elastically up to the breaking point, and assuming a connection between rupture and the melting phenomenon, Fürth obtains an expression for the rupture stress a, in the form where Q is the melting energy per unit mass, p is the density, and is Poisson's ratio. Furth compares fracture stresses computed from Eq I with the fracture stresses of metals as given in the Landolt-Bernstein Tables (1927) and in the Hand-

Jan 1, 1947

By Edward Saibel

The various theories that have been advanced to explain or predict the conditions under which a metal fractures may be divided into two categories: First, there are the macroscopic theories generally used in engineering practice. These are empirical in nature and limited in application. For example, the maximum normal stress criterion, which is quite satisfactory for a mild steel in simple tension at atmospheric pressure,' no longer suffices when this steel is pulled under hydrostatic pressure.2 In all of these empirical theories, the critical condition characteristic of the material and of the loading conditions must be obtained experimentally. Secondly, there are the theories based on interatomic forces,3'4 or on the energy required to form new surfaces.5,6 These have all dealt with the theoretical evaluation of the tensile stress necessary to bring about rupture in a purely brittle manner; that is, without plastic flow preceding fracture. All of these attempts have led to values of the tensile strength of crystals or of polycrystalline bodies that are 100 to 1000 times higher than observed values. On this account, it has been thought necessary by some investigators to conceive of a microcrack structure or distribution of flaws throughout the specimen such that the resulting stress concentrations provide the factor necessary to bring about agree- ment between calculation and experiment. It has been pointed out by several observers' that this point of view is highly unrealistic, in that the weakening effect of these flaws or microstructures must be very uniform from specimen to specimen, since the fracture stresses found for various specimens of the same material tested under similar conditions are so nearly constant. Furthermore, since calculations based on atomic forces or atomic energy are for purely brittle fracture, a condition probably never satisfied in tests, agreement is hardly to be expected. Thermodynamic Theory of Fürth In order to resolve this apparent discrepancy between the theoretical cohesive strengths and the observed fracture strengths, Fürth8 advanced a thermodynamic theory of the tensile strength of isotropic bodies based on work of Born relating to the melting of crystals. Assuming an isotropic material free from imperfections and flaws, behaving elastically up to the breaking point, and assuming a connection between rupture and the melting phenomenon, Fürth obtains an expression for the rupture stress a, in the form where Q is the melting energy per unit mass, p is the density, and is Poisson's ratio. Furth compares fracture stresses computed from Eq I with the fracture stresses of metals as given in the Landolt-Bernstein Tables (1927) and in the Hand-

Jan 1, 1947

By P. Thapliyal

The petroleum refining industry generates over a million tons of spent catalyst per year, containing valuable metals. Currently, these materials are recycled to smelting furnaces, but the fundamental mechanisms controlling the recovery processes are poorly understood. Furthermore, submerged injection of finely divided materials is potentially a means to obtain high recoveries of pay metals. In this study, a catalyst containing 10% Ni and 1% Co was injected into 45 kg heats of matte. A copper matte was chosen so that the nickel and cobalt recoveries were measurable. It was found that the recovery ranged from 40 to 700Al, increasing with catalyst feed rate, decreasing with catalyst particle size and decreasing with the oxygen content of the carrier gas. A mathematical model was developed to account for the results, and to permit extrapolation to nickel mattes. The industrial implications are discussed.

Jan 1, 1996