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By G. E. Johnson

The problem of efficient reclamation of zinc base die cast scrap became interesting early in 1930. Die Cast Metal, as referred to in this paper, is a zinc base alloy with various proportions of aluminum, copper, magnesium, antimony and tin. Many attempts were made to work out some means of reclaiming the discarded die cast metal for re-use as new die cast metal. Difficulties in such reclamation were attributable to contamination by lead and tin from solder, chromium and nickel from electroplated coatings, and iron from iron inserts. This paper relates the experiments that led to the development of a specialized muffle furnace for the treatment of zinc base die cast scrap for the production of zinc oxide and zinc, and describes the development of the muffle furnace and the equipment now used commercially for these purposes. The Eagle-Picher Co. acquired all patent rights' for these developments from the International Smelting and Refining Co. in connection with their purchase of the East Chicago Plant. Zinc Base Serap Situation About 1935, the die cast scrap situation became increasingly acute for scrap dealers. This scrap was accumulating from dismantling automobiles and household appliances which contained die cast parts. Efforts to find an outlet for this type of scrap were intensified. The International Smelting and Refining Co. began to study the possibilities of a commercial process for the recovery of values from die cast scrap. At that time most of the die cast metal reclaimed was melted down in small kettles of from one to five tons capacity, the iron inserts being removed by skimming. The dross was skimmed off and disposed of as a zinc dross. The drossed metal was cast into slabs and was given the trade name "die cast slabs.". Distribution of the products produced by melting die cast scrap in kettles is shown in Table 1. American Process Experiments A method considered for the production of zinc oxide from die cast scrap was an adaption of the standard American Process of zinc oxide manufacture. Thus some die cast scrap was mixed with oxidized zinc materials and charged to Wetherill grates. The zinc oxidized to zinc oxide but, while the aluminum and copper largely remained in the residue, the color of the zinc oxide produced was impaired by copper contamination. As the proportion of die cast scrap was increased, liquation took place; that is, the metal trickled through the charge then solidified in the openings of the grates. French Process Experiments Several hundred tons of die cast scrap were purchased for test purposes and converted into die cast slabs. These slabs were charged into a French Process (horizontal retort) zinc oxide furnace with some electrolytic zinc. A satisfactory grade of zinc oxide was not produced. Distillation in Belgian Retorts It was then decided that, rather than attempt to use scrap die cast metal or scrap zinc for the production of zinc oxide, it would be advisable to redistill the die cast slab metal in a Belgian retort furnace. The opportunity to do so was provided by the closing of the zinc smelter of the Illinois Zinc Co. at Peru, Ill. Arrangements were made for the operation of a Belgian retort furnace for such redistillation purposes. The results of this experiment are summarized in Table 2.

Jan 1, 1950

By John W. Nebgen

This report contains findings from a U.S. Bureau of Mines study concerning the inhibition of acid mine drainage formation from underground coal mines. A series of experiments was performed in which three different pyritic materials (wastes from coal production plants) were evaluated using several candidate inhibiting agents. Data obtained from the inhibitor-treated pyrites were compared with data from control experiments in which untreated pyritic wastes were used. The experiments were conducted by placing treated and untreated pyrite in columns, passing moist air through the columns to promote oxidation of pyrite, and washing the columns weekly to collect oxidation products for analysis. Experimental results indicate that quantities of acid mine drainage can be substantially reduced if soluble iron III (ferric) ion is controlled. The best inhibitors are neutral or alkaline siliceous materials such as fly ash, blast furnace slag, portland cement, and cement kiln dust. These materials appear to insolubilize iron III species to make them unavailable for reaction with pyrite. The data strongly suggest that the soluble ferric ion aqueous is a key oxidant for pyrite to produce acid mine drainage. The role of aqueous ferric ion as an oxidizing agent is substantiated further by data obtained using metallic iron (nails) as an inhibitor. The iron nails tended to keep the soluble iron in the iron 11 (ferrous) state. Experimental results indicate that sulfate and acidity levels are reduced when pyrite is in contact with the metallic iron.

Jan 1, 1979

By J. A. Finch, Zhenghe Xu, Z. A. Zhou

A particle-bubble collision model was used to investigate the minimum recovery zone height, H(r,min) required for flotation columns. The criterion used to define H(r,min) is that height which gives unit collision probability. It is shown that H(r,min) is determined by particle and bubble size, gas hold-up and bubble-bubble interaction. Under typical operating conditions, for flotation of particles less that 10 micrometres in size H(r,min) is greater than 10 m, but it reduces to less than 1 m for particles greater than 100 micrometres

Aug 1, 1995

By L. A. Vaisberg

"Crushing and grinding are the two most common industrial processes. These processes consume nearly 20 per cent of the entire electric power produced worldwide. This enormous amount of electric power consumed results from the fact that modern crushing and grinding machines employ the processes first introduced by the prehistoric man, namely those of compression, impact, attrition, and cutting. The material thus handled decomposes indiscriminately, and almost completely ignoring the microscopic cracks and other defects of its structure. Apart from the irrational use of the power, the crushing and grinding processes currently in use result in irretrievable loss of useful components or else in a substantial deterioration of the final products obtained, all as a result of incomplete grinding or, reversely, of overgrinding, palletizing, or fracture of particles.The principal type of equipment that has almost universally been used all over the world for more than 150 years for crushing both natural and synthetic minerals comprises unbalanced jaw and cone crushers. The driving element of crushing bodies in these machines is an unbalanced weight, which transfers the crushing body, allowing it to squeeze the material within the eccentricity value only. The maximum reduction ratio achieved by such a drive is 5, which is due to the rigid kinematic arrangement of the crusher, its dynamic unbalance, and the impossibility of increasing the number of impacts on the material being crushed. Moreover, conventional machines cannot cope with super hard materials, and their mechanism is vulnerable to damage by uncrushable objects.On the basis of fundamental research into the theories of solid body and vibration, OAO Mekhanobr- Tekhnika have developed a range of vibrating jaw and cone inertia crushers that make a reduction ratio of 30 feasible in an open-circuit operation with the reduction ratio monitored within a wide range. In these crushers, the eccentric drive is replaced with a vibrating one. In this way the rigid kinematic drive became dynamic, thus allowing pieces of material to be crushed in a thick layer due to the effect of their bumping into each other, and with the amplitude changing automatically. This results in a number of advantages as compared with conventional crushers:"

Jan 1, 2003

By Dale Preece

A carefully designed and controlled in-place destruction experiment was performed on a concrete bunker buried in 4.27 m (14 ft.) of soil. The objective was to determine if the explosive charges would collapse the structure in-place without requiring mechanical excavation. Collapse of the buried structure was first attempted by drilling holes in the soil and placing four 13.38 Kg (29.5 lb) Comp B explosive charges at a depth of 2.13 m (6.7 ft.). The configuration of the charges when detonated was 2.13 m (6.7 ft.) off the top of the concrete roof and 3.66 m (12 ft.) apart in a square pattern. Detonation of these charges created a crater ~4.88 m (16 ft.) in diameter and 2.13 m (6.7 ft.) deep, leaving ~2.13 m (6.7 ft.) of soil covering. Very limited spalling occurred on the ceiling of the concrete structure as a result of detonating these four charges. The second attempt to collapse the structure consisted of placing another single 13.38 Kg (29.5 lb) charge, identical to the first four, near the geometrical center of the bunker roof. This charge was detonated in the soil cover 100 to 200 mm (4 to 8 in.) above the reinforced concrete roof, collapsing it. Due to the collapsed roof and remaining soil cover, the structure had been collapsed in place, requiring no further demolition.

Jan 1, 2006

By E. Matinde

Human beings have been dependent on metals and alloys for livelihoods since time immemorial. In fact, there is irrefutable evidence that successful ancient civilizations achieved supremacy over their environments through the mastery of metals and alloys (Miller, 1995; Mtetwa, 2022). Over time, metals and alloys have evolved to become ubiquitous engineering materials indispensable to mankind, with applications in industrial and residential infrastructure, agriculture, energy generation and storage, transportation and communication systems, and manufacturing, among others (Elshkaki et al., 2018; Watari et al., 2021). Population growth, technological developments, and increase in urbanization and industrialization are all intricately linked to the intensity of use of metals and alloys. With up to 5 billion people estimated to live in urban areas by 2030 (Armstrong, 2009), the demand for metals and alloys will inevitably increase in order to satisfy the increased demand for infrastructure, machinery, and other human needs (Elshkaki et al., 2018; Watari et al., 2021). According to LePan (2022), urbanization and growth of mega-cities will increase the demand for metals and alloys, such as nickel, steel, aluminium, and copper by 116%, 50%, 57%, and 26%, respectively, between 2019 and 2035. Naturally, the production of metals and alloys from natural ores, secondary resources, and/or a combination of both, to meet this increased demand will invariably lead to the increase in generation of deleterious emissions in the form of wastes. In fact, mining and metallurgical wastes currently constitute the world’s largest anthropogenic streams by mass, often containing a high concentration of elements and compounds that can cause potential damage to natural ecosystems and humans (Hudson-Edwards et al., 2011; Lottermoser, 2011; Matinde et al., 2018; Seetharaman et al., 2022). Obviously, society’s heavy reliance on new mineral resources to drive the emerging energy transition entails that the legacy of these waste streams will continue unabated for the near-foreseeable future. The scarcity of high-grade mineral reserves, coupled with deliberate efforts to solve the anthropogenic circularity conundrum, therefore introduces a high level of urgency in the metal extraction industry to develop nascent and more eco-friendly processes and technologies. Integrating circular economy principles based on intentional configurations of circular industrial ecosystems in order to maintain the value of materials and resources in the economy for as long as possible is widely accepted as a practical approach to mitigating the negative externalities imposed by

Sep 1, 2024

By A. MacG. Robertson

A cone penetrometer has been used to assess the level of stress existing in hydraulically placed mine backill. The test apparatus was fabricated at the mine and consisted of a steel cone, connector rods and a hydraulic jack. Testing was carried out from a manway passing through the centre of the stope. The cone was pushed horizontally into the fill, both at right angles and parallel to the orientation of the stope walls, and the resistance to penetration was measured. Corrections were made to allow for friction along the rods. In a cohesionless sand, such as mine fill, the point resistance should be directly related to the in situ stress. The stresses in mine backfill are due to o the self weight of the fill o convergence of the footwall and hangingwall of the stope. Silo theory was used to estimate that component of the in situ stress due to the self weight of the fill. The difference between the stress predicted by silo theory and the stress estimated from the cone resistance was assumed to be due to convergence of the stope walls.

Jan 1, 1986

By Christopher Van Dyke, Edward L. Petsonk, Knox Van Dyke, Vincent Castranova, Ji-Hee Kang, William Pailes

"INTRODUCTIONPlatelet-activating factor (P AF) has been shown to mediate a broad range of biologic activities (1). Chemical analysis has shown that PAF is a glycerophospholipid with a choline polar head group, an ester-linked acyl chain at the second carbon of the glycerol backbone, and an ether linkage at the first carbon. The alkyl group attached to the first carbon can exist in a variety of chain lengths, with the C16 and C18 forms predominant in humans. The structure of P AF has been identified as 1-0-alkyl-2-acetyl-sn-glycerol-3-phosphorylcholine (2,3).PAF can be released from a variety of cell types, such as basophils, neutrophils, and alveolar macrophages ( 4-6). Stimuli for the release of P AF include calcium ionophore, phorbol esters, chemotactic agents, and zymosan. In addition, endotoxin has been shown to be a potent stimulant of P AF release from alveolar macrophages (7).P AF has been shown to have a number of pulmonary effects. It has been associated with asthma since it can cause contraction of pulmonary tissue (8) and leukotriene secretion from leukocytes (9) and induce airway constriction when inhaled by humans (10). In addition, PAF is a potent chemoattractant and can cause migration ofneutrophils into the airspaces of the lungs (11,12). Endotoxin is a lipopolysaccharide-protein complex derived from the cell walls of gram-negative bacteria. I.PS is the lipopolysaccharide portion of endotoxin. LPS contains four covalently joined subunits: lipid A, 3-deoxyoctonate, a core polysaccharide moiety, and an 0-specific antigenic polysaccharide side chain. Rough LPS contains no 0-antigen side chain. The liP.id A portion of LPS has been associated with most of the biolQgic effects of endotoxin (13). This lipid A subunit consists of a D-glucosamine disaccharide backbone substituted with four fatty acid side chains. Endotoxin is found in a wide variety of occupational settings associated with organic dusts derived from plants or animals, such as cotton, cereal grains, silage, rice, and poultry (14-18). In addition, airborne endotoxin has been found in sewage treatment plants, composting plants, offices with contaminated humidifiers, and showers or saunas (19-22)."

Jan 1, 1990

By I. C. Spangenberg

The status of sampling practices in the gold mining industry in Africa was determined as an initial step in a process to standardize sampling practices in the mining industry. Twenty-one gold mines, twenty metallurgical plants, and thirteen laboratories were rated for the potential influence of the relevant sampling errors on each component of the particular sampling system. The findings of the study on the status of equipment, standards, procedures, and management principles were presented in a dissertation (Spangenberg, 20121) and are now used by AngloGold Ashanti?s mines in the quest for correct sampling practices. The information is also used to compile a guideline on leading practice procedures for sampling methods in gold mining. This article is an overview of sampling best practice found in African mining Keywords theory of sampling, best practise, sampling errors, sampling standards.

Jan 1, 2014

By I M. Turnbull

QMAP (the Quarter Million Mapping Programme, 1:250 000 scale) is a geological mapping programme which will build a digital geological database of the whole country and publish maps and books to document it. The programme was established in 1993, following a recommendation by a review panel appointed by the Ministry of Research, Science & Technology, and is funded by the government, from the Public Good Science Fund. The relevance and fundamental value of QMAP lies in the greatly improved geological knowledge it will provide for researchers and other end-users of geological information.   QMAP research involves assessment of previous work, field and laboratory investigations in key areas, and data storage, manipulation and publication using Geographic Information Systems (GIS) computer technology. The QMAP digital database of New Zealand geology will be completed by 2006, as will the series of 21 full colour printed geological maps and accompanying explanatory texts. Two are already completed and published (Kaitaia and Dunedin), and six other projects are well advanced.   QMAP information will also be available in digital form. Next year we hope to expand the scope of the programme to cover the reconciling and linking of many other earth science databases to QMAP, because we believe this will create a powerful research tool. The intention is to develop internet access to the databases, to make the information publicly available.

Jan 1, 1997

By Edwards A. B

The following note on the mineral association in the ores of the Tennant Creek Goldfield, Northern Territory, is largely based on Mineragraphic Reports Nos. 49, 89, 117 and 193 of the Council for Scientific and Industrial Research. These reports are the results of the examinations of auriferous specimens from a number of mines of the goldfield and are now supplemented by the examination of further specimens from Mt. Samuel forwarded by Mr. V. G. Martin.The Tennant Creek Goldfield lies in the central portion of the Northern Territory, about Lat. 190 35', Long. 1340 15', on the Overland Telegraph Line and about 369 miles north of Alice Springs. It comprise an area extending about 50 miles east and west, by 30 miles north and south.The geology of the goldfield has been described by Woolnough. (2)The rocks of the area are of pre-Cambrian age, and consist of talcose, chloritic, micaceous and siliceous schists of sedimentary origin, interbedded with flows or dykes of schistose quartz porphyry, and of granites which were intruded subsequent to the regional metarporphism of the area. The rocks are moderately folded, but the beclding tends to be obscured by a pronounced east-west cleavage. The most continuous orebodies run east and west, parallel with this cleavage.Numerous lenses of hematite occur in the schists, with their long axes, parallel to the cleavage, and the gold values of the field are frequently associated with such hematite bodies. The dimensions of these hematite bodies are variable but rarely exceed a length of 300 ft., with an average thickness between 10 and 30 ft.; the original vertical dimensions are thought to be comparable with their length. The lenses tend to occur in groups when they are arranged en echelon both horizontally and in depth; and erosion has exposed individual lenses to different degrees, ranging from incipient exposure to complete removal. The existence of unexposed hematite lenses at depth has been proved by geophysical surveys, coupled with drilling tests. (3)A few of the bodies are pipe-like. Many are surrounded by a casing of brecciated rock, composed of fragments of hematite and shattered country rock, and presumably caused by subsequent earth movements which crushed the country rock against the resistant hematite bodies. In the early days of the field most of the important gold occurences were found within these crushed zones, or, to a less extent, within the hematite bodies themselves.These occurrences appeared to be associated only with those hematite lenses which were intersected by quartz veins or other lines of weakness, of later origin than the crushing. This led Woolnough to think that the introduction of the gold and attendant bismuth was subsequent to the...

Jan 1, 1942

During the period 1979 thru 1982, Multi Mineral Corporation conducted a mining research program at the United States Department of the Interior's Bureau of Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and, the results are described in this report.

Jan 1, 1983

On June 4, Kennecott Utah Copper (KUC)marked the centennial of the founding of the original company. Bill Champion is president and chief executive officer of KUC. He said, “What has happened during the past 100 years far surpassed even the most optimistic visions of men like Daniel C. Jackling and Robert Gemmell when they promoted the concept of mass production techniques for a low-grade deposit of copper ore. At that time, it was a totally new way of doing things and the mining leaders of that day scoffed at the idea. They said it would never work,” Champion said. The company will celebrate this once-in-a-lifetime occasion with a few special projects, mainly for the benefit of our employees, said Louie Cononelos, director of government and public affairs for KUC. The company has designed and minted a commemorative copper coin that reflects early steam shovel and locomotive operations on one side, and today’s modern electric shovels and huge haulage trucks on the other side. “The history of the company stems from the ores of the Bingham Canyon Mine. That coin has been encased as part of a10-panel brochure that captures the company’s 100 year history,” he said. KUC also developed special centennial banners and comparable framed posters that were displayed throughout its operations and at selected community locations that have enjoyed a long-time partnership and special relationship with the company. Some of the plants also designed their own centennial hardhat decals.

Jan 1, 2003

By John Nagy, Hylton R. Brown, Irving Hartman

"INTRODUCTION The tests described in this publication were planned to provide information on the explosibility of metal-powder dust clouds. This subject has become increasingly important because of the large quantity and variety of metallic powders now used for military and industrial purposes. To provide the increased amounts of metallic powders needed in the manufacture of munitions and to supply the demand created by the rapid growth of powder metallurgy, existing metal-powder plants have been enlarged, production schedules accelerated, and new plants erected. In some cases new methods of producing metal powders have been developed. This increased production and the development of new manufacturing methods have caused an increase in the number of metal-powder fires and explosions, with accompanying heavy loss of life and property. These have emphasized the need for information on methods of providing protection against hazards inherent in the production and handling of powdered metals. This paper gives results of laboratory inflammability and explosibility tests made to April 1, 1943, and is a progress report. Many descriptive details have been omitted purposely; they will supplied in a later publication, expected to be a Bureau of Mines bulletin."

Oct 1, 1943

By Horace C. Knerr

It has been shown that the resistance to corrosion of duralumin sheet is greatly influenced by the quenching medium used in heat treatment, or, more specifically, by the rate of cooling during quenching. The severity of corrosive attack after exposure to salt-water spray increases in .the following order: The tensile strength, yield point and elongation are only slightly affected by the quenching medium, as shown in Table 1. Tensile test requirements: yield stress, 25,000 lb. per sq. in. minimum; ultimate stress, 55,000 lb. per sq. in. minimum; elongation in 2 in., 18 per cent. minimum.

Jan 1, 1931

By Thomas P. Mucho, Dennis Dolinar, Christopher Mark

Horizontal stresses are caused by global plate tectonic forces. During 1995 alone, they were largely responsible for closing two U.S. longwall mines. This paper presents six case histories from Pennsylvania. West Virginia, Kentucky and Alabama. In each case history, a mine encountered roof falls or difficult ground conditions in the headgate, caused by horizontal stress concentrations. The problems are detailed and the control measures adopted are described. In most cases, nearby longwall panels without stress concentrations were trouble-free. The paper also discusses detailed measurements made at two adjacent Pennsylvania longwalls. One headgate was oriented to avoid a horizontal stress concentration, and the other was not. Eliminating the stress concentration dramatically reduced roof support loads and roof deformation. The paper concludes that proper panel orientation and sequence is the key to maintaining headgate ground control. The optimum orientation is not parallel with the maximum horizontal stress, as previously thought but rather 200 in the stress shadow of the gob. Other stress control techniques, including artificial support, are briefly discussed.

Feb 24, 1997

By K. E. Gray, M. S. Seth

In Part I of this work,1 equations of elasticity were formulated for transversely isotropic, axisymmetric, homogeneous, porous media exhibiting pore fluid pressure. Equations of elasticity and the thermal analogy method were used to determine transient horizontal, tangential, and vertical stresses and radial displacement in a semi-infinite cylindrical region when either a constant rate of pressure or a constant rate of flow is maintained at the wellbore. In this paper, the approach presented earlier is extended to finite reservoirs for the cases of (1) steady-state flow, (2) constant pressures at the well bore and outer boundary and (3) constant pressure at the wellbore and no flow at the outer boundary. Results of this work show that radial and tangential stress gradients are high near the wellbore but diminish rapidt; away from the well; the vertical stress gradient behaves in the same way but is less severe. Radial stresses are compressive or neutral, whereas tangential and vertical stresses may be tensile, neutral or com-pressive, depending upon the boundary conditions, the physical Properties of the system and the radial distance involved (vertical stresses are always compressive in an unbounded system1. For constant boundary pressures, both radial and tangential stresses increase with time whereas they both decrease for a closed outer boundary and constant pressure at the wellbore. The vertical stress decreases with time for both systems. For steady-state systems, radial displacement may be positive or negative, depending upon the dimensions of the system, the pressure differential and the porosity. Radial displacement may be positive or negative for a closed outer boundary but is positive for constant pressures at both boundaries. INTRODUCTION The importance, utility and complexity of a realistic appraisal of the stress state at and local to a wellbore were indicated in Part I. In this paper the analytical approach presented earlier is extended to finite, cylindrical reservoir geometry for the cases of (1) steady-state flow, (2) constant pressures at wellbore and outer boundary and (3) constant pressure at the wellbore and no flow at the outer boundary. Other than the outer boundary of the reservoir being finite, the physical system and assumptions pertinent thereto are the same as before. The reader may wish to review the mathematical development through Eq. 49 of Part I before proceeding here. SOLUTION FOR GENERAL BOUNDARY CONDITIONS THERMAL STRESSES AND DISPLACEMENTS Since normal stresses do not exist at the free boundaries of a system subjected to thermal stresses, the boundary conditions are

Jan 1, 1969

The ready solubility of gold in dilute aqueous solutions of the cyanides of the alkalies or alkaline earths provides a convenient method for the separation of the precious metal -from the large surplus of associated materia1. The finely ground ore is pulped with a weak solution of cyanide, agitated to dissolve the gold, filtered and washed. The lowgrade filtrate is then clarified and the gold precipitated by some electronegative agent, the most usual being finely divided zinc or zinc dust. The slight precipitate is collectedon some form of filter coated with a filter aid, the filter cake being then known as "gold slime".A typical analysis of this slime is given in Table 1.

Jan 1, 1956

By Amanda de Angelis Vitoi

A nitretação do aço inoxidável endurecível por precipitação do tipo 17-4PH foi estudada comparativamente pelos processos de Plasma-DC e de Tela Ativa. Os resultados mostram que os dois processos são eficientes em promover a formação da camada nitretada de elevada dureza superficial, cerca de 1300 HV0,025. Entretanto, diferenças importantes são observadas. No processo de Plasma-DC a camada nitretada é composta, além da martensita acicular saturada em nitrogênio, de nitretos de ferro e cromo precipitados pela supersaturação. No processo de Tela Ativa a precipitação de nitretos de cromo é praticamente suprimida e predominando os nitretos de ferro. Esta diferença na sequência de precipitação de nitretos é inferida como sendo causada pela oferta de nitrogênio. Em Plasma-DC a oferta de nitrogênio é suficiente para a precipitação do nitreto de cromo, o que não ocorre em Tela Ativa. A maior profundidade de camada e de endurecimento transversal confirma a maior difusão de nitrogênio em Plasma-DC. Ainda, em ambos os processos a dureza de partida do substrato envelhecido é preservada após o ciclo de nitretação.

Aug 16, 2017

By Patrick R. Taylor

In the search for the development of more "environmentally friendly" and more intensive waste disposal approaches to meet more and more stringent environmental regulations, thermal plasma-based processes? are considered one of the most promising alternatives to well-established technologies such as incineration. This paper presents an overview on the research and development status of thermal plasma-based waste remediation technologies. The properties of thermal plasma are described. Due to its unique feature of high-energy intensity and super high temperature, thermal plasma is particularly capable of destroying organic-containing wastes. Its potential and promising application to waste remediation may include: treatment of incinerator ashes; metallurgical dusts (especially, electric arc furnace dust); medical wastes; radioactive wastes; and other Resource Conservation and Recovery Act (RCRA) listed hazardous wastes. Many research institutes and vendors have been involved in the development of thermal plasma-based waste treatment-technology encouraged by the cleanup programs supported by the Environmental Protection Agency (EPA), the Department of Energy (DoE) and the Department of Defense (000). More recently, thermal plasma-based waste treatment technologies (sometimes called plasma-enhanced pyrolysis) are focused more and more on not only just destroying organic wastes but also on how to practically, and economically recover energy contained in the organic waste materials in addition to the recovery of metals in order to offset the high operating costs.

Jan 1, 2003