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By Vladimir G. Kochnev

Crushing and grinding account for the major portion (60 to 80 percent) of the overall expenses for ore processing. Autogenous (AG) and semiautogenous grinding (SAG) have been considered a step forward in comparison to conventional grinding circuits with several stages of crushing and using ball (and/or rod) grinding mills (Bassarear, 1982, MacPherson, 1989, Pithois, Casalis, 1983, Maripuu et al., 1983). However, there remains room for improvement to existing AG and SAG technologies and both technologies have immense economic benefit potential. Experience gained by the Technics & Technologies of Disintegration Ltd. (TTD) in the research of grinding processes shows that grinding in AG and SAG mills can be performed in a more effective way. The company's approach comprises the following elements: ? Novel mill design. ? New liners and lifters. ? Novel discharge grid design. ? Technique of treating material of critical particle size. Comparative tests that demonstrated the usefulness of these innovations are described in this article. Currently, there are hundreds of AG and SAG mills in operation throughout the world. Application of new internal elements of the mills and reconsideration of the circuit design of the existing grinding equipment using present technological solutions would significantly increase the throughput rate and diminish power requirement.

Jan 1, 2008

By Steve Kral

Mining is a risky business. The cost of exploring for new mineral deposits is high and the success rate of finding one worthy of development is relatively low. And once a deposit is identified, there is no guarantee that it will become a mine. Mining companies have to spend a lot of time and money on due diligence, prefeasibility and feasibility studies, and sustainable development and environmental issues before deciding whether the deposit will become a profitable mine. And then there are the millions of dollars spent in developing the deposit and building a mine. No wonder the mining industry has trouble attracting investment capital. Companies take a large risk in developing reserves and investors take a similar risk in investing in them. So mining companies must be as accurate as possible in determining mineralization that makes it to reserve status. After all, reserves are a company’s most important asset and one of the critical factors analysts and funding sources look at when determining if a mine or mining company is worth the risk.

Jan 1, 2003

By T. Yegulalp, M. Castaldi

As global energy demands increase, there will be a critical need to employ fuels that have minimal environmental impacts. While hydrogen is considered the ultimate fuel for that purpose, hydrocarbon based fuels will be in use for a considerable time and will probably be the first major source of hydrogen for next generation power systems. The best fuel for this transition will be natural gas because of the high hydrogen to carbon ratio. Natural gas hydrates have the potential to meet the global energy needs for the foreseeable future. The amount of energy stored in natural gas hydrates is significantly more than that of all the other fossil fuels combined. However, most proposed techniques for recovering the natural gas from the hydrate require too much energy input, raise safety concerns or can only recover a fraction of the gas. This paper discusses the technical feasibility of a novel method of gas production in hydrate reservoirs. The method is an in-situ process that creates a point heat source in the hydrate formation. This method not only significantly reduces the energy input, but also has the potential to sequester as much or more CO2 than would be produced from combustion of the natural gas produced, thus making this in-situ methane production technique virtually carbon neutral. Simulations using FEMLAB™ show that the method offers an energy efficient and environmentally friendly way to produce natural gas from hydrate reservoirs. Preliminary results indicate that it is possible to have an energy efficiency of nearly 90% for land based reservoirs for hydrate loadings of 20%. The simulation results also suggest that alternatives to a point source can be employed which may improve the process efficiency.

Jan 1, 2007

By Chester O. Ensign

The White Pine Mine is situated in the southwestern portion of the Keweenaw Peninsula of Upper Michigan approximately 6 miles south of Lake Superior (Fig. 1). It is east of the Porcupine Mountains in Ontonagon County. The ore deposit is about 70 miles southwest of the famous native copper deposits of the "Copper Country" lying northeast of Houghton. Geological conditions are different at every mine and create a special set of problems in dilution control. This paper is largely intended to describe the techniques applied in mine dilution control (grade control) at White Pine, and present results of the program. For necessary background information major geologic characteristics of the deposit, particularly those that exert control over the distribution of ore, are briefly discussed. Mining methods are described in considerable detail since applied grade control techniques are adapted to these.

Jan 1, 1964

By A. G. Mayton, L. Adler

The paper under discussion provides an excellent and concise study of compartment ergonomics for thin seam equipment. However, in accomplishing this, some very important operational aspects were ignored. Since these are likely to be determinant, the authors' response is solicited. The novel shuttle car with its cross-car, end-mounted compartment is operationally very different from the current one. The latter can be considered a highly mobile extension of the continuous miner or loader, with a pass-through conveyor, dump boom, and extra storage. As such, the vehicle's kinematics are the simple "I," or shuttle pattern, bent for going around pillars, with an intermediate stop at the "change-out point" (Adler, 1986 ). The action of the cable reel adjusts well to this pattern. The proposed shuttle car's motion either superimposes a "Y," time is lost (5 seconds) for each cycle, space is needed, line of sight is compromised, and a cable anchor is probably required at the dump. A chute is almost prohibitive in construction time and cost. The lack of a dump boom further curtails flexibility in the proposal. The value of a standard hand and opposite standard hand configuration also needs consideration. Many front-end loaders have a rocker (overshot) capability that is designed to achieve an "I” pattern. And crawler loaders sometimes use a side dumping bucket variant for the same purpose. These examples indicate the pattern's importance. For underground, thin seam application, the ram car has become popular. This is an articulated truck, battery-powered, and with an ejector dump. Its operational patterns would be similar to the novel shuttle car, except without the loading flexibility provided by a conveyor. Since the cab location of the proposed shuttle car largely obviates some of the major advantages of the present shuttle car, the question arises whether this configuration could be adapted to the current ram car and scoop

Jan 1, 1991

By L. Adler

The paper under discussion provides an excellent and concise study of compartment ergonomics for thin seam equipment. However, in accomplishing this, some very important operational aspects were ignored. Since these are likely to be determinant, the authors' response is solicited. The novel shuttle car with its cross-car, end-mounted compartment is operationally very different from the current one. The latter can be considered a highly mobile extension of the continuous miner or loader, with a pass-through conveyor, dump boom, and extra storage. As such, the vehicle's kinematics are the simple "I," or shuttle pattern, bent for going around pillars, with an intermediate stop at the "change-out point" (Adler, 1986). The action of the cable reel adjusts well to this pattern. The proposed shuttle car's motion either superimposes a "Y," time is lost (5 seconds) for each cycle, space is needed, line of sight is compromised, and a cable anchor is probably required at the dump. A chute is almost prohibitive in construction time and cost. The lack of a dump boom further curtails flexibility in the proposal. The value of a standard hand and opposite standard hand configuration also needs consideration. Many front-end loaders have a rocker (overshot) capability that is designed to achieve an "I" pattern. And crawler loaders sometimes use a side dumping bucket variant for the same purpose. These examples indicate the pattern's importance. For underground, thin seam application, the ram car has become popular. This is an articulated truck, battery-powered, and with an ejector dump. Its operational patterns would be similar to the novel shuttle car, except without the loading flexibility provided by a conveyor. Since the cab location of the proposed shuttle car largely obviates some of the major advantages of the present shuttle car, the question arises whether this configuration could be adapted to the current ram car and scoop.

Jan 1, 1990

By J. C. Yingling, J. W. Leonard

Introduction The absence of coal-face particle management heavily penalizes the transportation of coal from initial loading to final consumption. The penalties include dust problems, significantly reduced mine-loading-cycle productivity, mine-belt spillage, excessively high coal-preparation costs, chute blockages and dangerous pulverizer blockages at the final point of utilization. Fine particles commonly cause environmental and economic problems. It is well known that these fines can cause safety and environmental dust problems. But it is not well understood that these fines can also swell broken coal to a point where 5% to 15% more time and capacity must be used to deliver the same tonnage. In this paper, methods and rewards for reducing and/or managing fines at the mine face are discussed. Computer-based loading-cycle model productivity estimates, viewed from a new perspective, are made on the basis of material volume rather than on the long-established, and frequently misleading, basis of tonnage. It is typically the volume of broken material being transported that defines the capacity of a given transportation system, while the corresponding tonnages are merely a reflection of the specific material densities. Published evidence suggests that the swelling of broken coal can be decreased very significantly using small quantities of certain nonfrothing chemicals, which are added to mine-face spray water, and by employing improved mine-face breakage practices. In a future paper, the effects on transportation productivity beyond the coal mine will be discussed. The precursor to the work presented in this paper, involving the bulk density improvement for broken coal and the subsequent production gains for underground coal mines, was earlier presented in Leonard and Newman (1989). In the past, this topic has been studied and practiced only in byproduct coking in the steel industry. However, a potential exists for an increase in coal-industry productivity by improving the bulk density of coal to yield a subsequent reduction in delivered cost. This can occur with breakage, handling and treatment methods resulting in the loading of greater quantities of coal in fixed volumetric capacity haulage units such as mine cars, shuttle cars and scoops. Laboratory-based experiments to achieve an increase in productivity by increasing coal bulk density were discussed in Leonard, Paradkar and Groppo (1992). Chemical techniques using small quantities of commercially available reagents (surfactants) resulted in about a 13% to 15 % increase in bulk density, which was thought to produce a proportional increase in the productivity of a mine, together with a subsequent reduction in cost. The idea is to mix the reagents with the water that is used to spray coal during mining. In this paper, the impact of bulk density improvements on production rates is presented. Increases in production ranging from 60% to 88% of the bulk density increases are projected. This analysis was performed for atypical continuous-miner section. In the following sections, discussion and results of the analysis are presented. Discussion An analysis was performed to ascertain the impact of bulk density improvements on face-production rates for a typical continuous-miner section. Figure 1 illustrates the section layout and cut sequence. This layout and sequence is identical to the case described in King and Suboleski (1991). As can be seen, the section uses five entries and 12.2-m cuts that are taken by a remotely controlled continuous miner. The seam height is 1.5 m and two shuttle cars (5.7 t nominal capacity) are employed for haulage from the miner to the section feeder, which, throughout the cut sequence, is positioned as illustrated in Fig. 1. The simulation model was coded in the SIMAN simulation language. The major impacts of increased bulk density improvements on such a production system are as follows: •Shuttle-car payloads, in terms of the mass of coal transported per haul cycle, are increased proportionally to the increase in bulk density that results from the application of surfactant. •Shuttle-car discharge times should remain largely unchanged, because they are determined by the volume of material that is discharged, rather than the mass, and this volume does not change.

Jan 1, 1996

By J. V. Bymark

It is the intent of this paper to discuss the autogenous grinding circuit at Hibbing Taconite. The scope of the presentation includes; a brief history, the process flowsheet and the steps taken to improve mill productivity, availability and metallurgical performance. Hibbing Taconite is located near the center of the Mesabi Range in Northern Minnesota 100 miles from the Canadian border and 80 miles north of the Lake Superior Port Cities of Duluth and Superior. A 105 mile railroad connects us with the port of Superior, Wisconsin, where our pellets are loaded into lake carriers for lower lake destinations. It is worthy to mention the Mesabi Range's most famous landmark which is immediately to the south of our mine area. This is the Hull Rust Mahoning Mine which operated until the mid-1970's producing more than 700 million tons of red ore between 1893 and 1973.

Jan 1, 1985

By Jürgen Kretschmann, Christina Suarez, Jürgen Brune, Stefan Möllerherm

"The Ruhr region in Germany’s North-Rhine Westphalia is going through significant change. By the end of 2018, the last two underground hard coal mines in the Ruhr, Ibbenbüren and Prosper-Haniel collieries, will close their portals and bring an end to more than 200 years of coal mining and an industry that was once the economic and cultural backbone of the area. Ruhr is undergoing an impressive economic and cultural transformation, as it gradually shifts from being a region once dependent on coal and steelmaking to a post-mining region focused on redesigning itself as a cultural center. This article focuses on the socioeconomic impacts of the transformation into post-mining and the roles of the government, labor unions and local community to aid the transformation from the perspective of an American student. It will look into the cultural values that are helping to drive the transformation and compare them to American standards and values in order to determine if a similar approach can be used in the United States and its coal industry. History and backgroundUnderground hard coal mining has had a long history and a significant impact on the culture and economy in Ruhr since the early 19th 20century. The Ruhr region is located in the heart of the German state of North- Rhine Westphalia. Ruhr is bounded by the Rhine River in the west, the Ruhr River in the south and the Lippe River in the north, with the Emscher River running through its center.The Ruhr is home to around 5.1 million people and spans an area of approximately 4,500 km2 (1,730 sq miles). Before the era of industrialization, the Ruhr was a rural, agricultural region. Small-scale coal mining began in the 13th century, with coal being used for heating, cooking and metallurgical processes, including steelmaking. With 19th-century industrialization, coal mining became a significant driver of the region’s economic structure. Steam engines, and soon, electric motors, allowed for the pumping of mine water and for powerful hoists hauling from deep shafts, enabling miners to reach deeper coal seams that were once thought impossible to mine. The Ruhr mining boom began in the 1850s, supported by Prussian economic policies that attracted many workers and their families to the region. The population grew from 400,000 in 1850 to 5.7 million in 1957. The coal and steel industries were key contributors to Germany’s “Wirtschaftswunder” — or “miraculous economic recovery”— in the 1950s. In 1956, the coal industry reached its peak production of around 112 Mt/a (124 million stpy) of coal and employed almost 600,000 miners."

Mar 1, 2019

By David B. Brooks

I gratefully acknowledge the help of a number of American and Canadian geologists, in both federal surveys and in private firms, who took the time to discuss this problem with me. Hans Landsberg and Bruce Netschert also followed the study with interest and encouragement. In their 1961 monograph, THE FUTURE SUPPLY OF THE MAJOR METALS, Bruce Netschert and Hans Landsberg noted that identified potential resources (that is, known but submarginal resources) of lead and zinc were much lower relative to reserves (that is, known and supermarginal resources) than was the same ratio for other metals.1/ Put another way, it seemed that for such metals as iron, manganese, copper, and aluminum, slightly more favorable economic conditions or modest advances in technology would greatly increase reserves by permitting the exploitation of vest quantities of leaner or deeper or otherwise less valuable mineral deposits. But for lead and zinc, Netschert and Landsberg concluded that either: "(1) there is relatively little material below present cutoff grades; [or] (2) such material exists, but for some reason there are no data.? 2/ This situation, which they called "the lead-zinc anomaly" has been subsequently discussed by other authors. The purpose of this paper is to carry the discussion further by examining the evidence in favor of (1) and (2) and by advancing a third alternative.

Jan 1, 1967

By M. Javier

Mining is an industry of experimentation throughout human history. Recently, societies are giving a clear message about mining because many projects are being rejected around the world. These refusals are a generational reaction to the activity of mining. In practice, it generates the perception that mining is using the same methodology without attending to the gradual initiation of conflicts. This is in spite of the best engineering and technology of the time that are put in place at the presentation of those mining projects. Some of these rejected projects are geographically distant from each other, but the communities? rejection occurred during many cases under similar characteristics. This concern shows that the current model of mining projects needs to be replaced with a new one: A new Design, one within which the socio-environmental values of this millennium are inherent. This paper describes Mining Project 101 to help the industry to set the highest and cleanest standards for mining. It also presents its aspects to sustainability and nature, which provides the principles and procedures for designing, planning, and operating mining projects with sensitivity to nature. It offers methods of diagnostic, remediation, and extraction while at the same time preventing and preserving a physical, chemical, and biological equilibrium of nature. This emerging process will be a step up from having a mining industry unaccountable to the socio-environmental conflicts it perpetrates and will abandon the ?cosmetic? repair on the caducity of traditional models in today?s practice. In conclusion, we have the opportunity to change this model. KEYWORDS: Equilibrium in Nature, Geomímic, Deproduction, mine design.

Feb 27, 2013

By C. Okrusch, C. Roos, M. Akers, S. Rosenthal

Modern mining consistently faces controversy. Public sentiment impacts the permitting and development of mines, so a quality public relations (PR) program for mining companies may improve society’s impression of the mining industry. Developing mines face more permitting challenges than operating mines, which stems from a lack of societal trust given the history of mining and its impact on the environment. Two case studies were selected based on the type of public controversy they face to demonstrate how pervasive permitting issues are in industry. Both Pebble Mine, owned by Northern Dynasty Minerals (NDM), and Black Butte, owned by Sandfire Resources America Inc (SRA), experienced difficulties with their water permitting due to potential risks their mine developments posed to local fish populations. Pebble has, to date, failed in all of their attempts to become permitted due to concern for the water and the fish. Black Butte dealt with the same problems, on a smaller scale, but was able to become permitted. These two mines will be discussed in detail including local history, mine setting, mining history in America, prevalent culture groups, technology development, and intercultural communication competence (ICC). The mining industry needs to evaluate its ICC skills since ICC directly determines the effectiveness of PR. Based on Barna’s Stumbling Blocks for intercultural communication, methods for improving the mining industry’s PR will be suggested in the hope of easing the permitting process for future mines by developing ICC.

Mar 2, 2022

By C. M. Brinckerhoff

Much has been written in the mining technical magazines about the caving system. Many of these articles were published in the Transactions of the American Institute of Mining Engineers prior to World War II. In recent years little has been written on mining methods or on the detailed planning always required. Block caving had primarily been used to mine deep copper ores in Africa, the United States and in Chile, although other ores had been mined by this same system. Asbestos ore had been caved in Canada, tin ore in Bolivia, molybdenum ore in Colorado, iron ore in Wyoming and Sweden, and limestone in California.

Jan 1, 1984

By Steven E. Paulson

In situ mining is emerging as a potential alternative to conventional surf ace and underground mining techniques. A major factor in determining recoveries by in situ mining is the proportion of ore minerals that can be contacted and solubilized by the leach solutions. To provide basic information on the processes occurring during in situ leaching, particularly at the microscopic scale, the Bureau of Mines has developed a geologic characterization research program. This includes laboratory experiments using leaching apparatus that can accommodate whole core samples. Whole core experiments result in higher leach solution-ore mineral contact ratios than packed column experiments, and also allow for the assessment of permeability changes taking place as the result of mineral dissolution, precipitation, and clay swelling within the flow channels in the rock. A nonreactive, reusable reaction cell has been designed and tested. The leaching apparatus can be used for constant-pressure or constant-flow experiments and allows for the control of flow rate, pressure, and temperature during the experiments, thus permitting studies on a wide variety of ore samples. Details of the experimental apparatus and design are presented, as well as preliminary results from the first series of experiments on an oxide copper ore from the Casa Grande, AZ, area.

Jan 1, 1987

By Tom Gonzales

At San Manuel, AZ, Magma Metals Co. operates an Outokumpu flash furnace, four Peirce-Smith converters and two anode casting wheels that are supported by six anode vessels. Process gasses from the flash furnace and converters are treated in a two-train/ double-contact sulfuric acid plant. The plant captures 98% of the sulfur. A new flash furnace was commissioned in July 1988. It has since processed more than 2.7 Mt (3 million st) of sulfide concentrate without a major rebuild. The company has gained unique experience in the operation of the flash furnace at high oxygen enrichments with low off-gas dust loadings. New procedures have been developed to maintain secondary material generation at equilibrium and for maintaining metallurgical control of operating parameters. Process flow description At Magma's San Manuel plant, concentrates and other copper-bearing material are blended and conveyed from two separate areas of the plant to three 420 t (465 st) capacity wet charge bins located above the rotary dryer. Flash furnace silica flux is conveyed to a 227-t (250-st) capacity fine flux bin located adjacent to the wet charge bins. The concentrate and flux are blended in controlled amounts and fed into a 168-t/ h (185-stph) gas-fired rotary dryer. The wet charge enters the dryer at 8% moisture and is dried to 0.2% moisture. The dried charge is pneumatically conveyed to a 580-t/h (640-stph) dry charge bin located above the flash furnace. Flash furnace charge is drawn from the bin by two drag conveyors at a concentrate feed rate of 145 t/h (160 stph). The charge is mixed with enriched combustion air and injected into the furnace reaction shaft. In the reaction shaft, the charge is oxidized to form matte, slag and a rich SO, off-gas.

Jan 1, 1992

By R. L. Loofbourow

Reasons for reexamining underground mining include: 1. The assurance that more deep deposits of useful minerals will be found. 2. The existence of deeply covered deposits of industrial minerals near large markets where quarries are becoming depleted or are lacking. 3. Surface property values, zoning and other limitations on open pit mining. 4. Expectation that underground space will be increasingly used for transportation, power plants, storage and similar purposes. 5. The improvements which have been made in underground mining. During the last three or four decades many changes and improvements have been made underground. All underground construction and mining has benefitted to some extent but the effect on the productivity of labor employed with some methods- has changed little and the use of these methods has declined. Productivity of labor in other methods has increased substantially. The relative usefulness of mining methods has changed and a vital industry, bituminous coal, has been returned to health. In this paper, consideration is limited to nine methods used with high productivity during the period under review. These methods are not necessarily better than others but they may be considered the prime methods in the sense that, in our economy, many, low grade ores, coal and the principal industrial minerals could hardly be produced by less productive means.2 Although most of the examples cited are from mining as such., the first four methods discussed can be used for the construction of stable excavations of various' shapes in sound rock.

Jan 1, 1967

By D. H. Davidson

The basic principal in the ISL process involves the recovery of metal values by moving fluids through rock instead of moving rock. The process combines surface and sub-surface operations, with the economic performance controlled by four major factors; rates of fluid injection and production from wells; the rate of mineral solubilization; the volume of rock swept by the fluid; and the volume of solution processed through the system. This paper discusses various technical and economic parameters affecting these four factors and how they impact project costs.

Jan 1, 1985

By Z. Sample

"INTRODUCTION This past year commodity prices continued their dip with increased volatility causing market values to slide another 16% putting increased pressure on even the largest companies to improve their free cash flow.[1] Without a recovery in commodity prices in sight, companies must find a sustainable method to improve returns in the current economic climate. In an effort to improve plant sustainability, the mineral processing industry is investing in advanced automation technologies and innovative processing methods that are both more reliable and more efficient than ever before. One such breakthrough technology is Heap Leaching (HL). This method of extraction has certain advantages over traditional metallurgical methods making previously unsustainable operations economically feasible. While HL is already seeing use in the gold and copper industries among others, recent developments may allow for the use of HL to process primary sulfide ores which make up about 80% of today’s ores.[2] For this reason, this emerging technology is poised for exciting growth. Unfortunately, as with any process change, the implementation of HL projects requires significant training on both the control system as well as the underlying process, and further, due to the complex nature of the HL process, this can be a particularly difficult task. DEMOGRAPHIC TIME BOMB Even before the implementation of these new technologies, the availability of the skilled workforce has already become a significant problem for the mining and mineral processing industries. From a survey of 912 mining professionals, Stratum International found that a mere 0.4% of senior level candidates were between the ages of 25 and 34 and a similar proportion aged over 75 years.[3] This indicates that there is both a deficiency of young skilled workers and a skilled workforce that is retiring earlier than the previous generation. Combined with data published by the US Department of Labor stating that the median age of the mining workforce is approaching 50 years old, research suggests that up to 50% of skilled mining and mineral process professionals are expected to retire in the next 5 years, leaving with their irreplaceable knowledge and experience.[4] While it is projected that the labor pool will be sufficient to fill open positions, the real question is if this young workforce will have necessary skill sets and experiences. In addition to a rapidly aging workforce and an inexperienced labor pool, a study done by the Oil and Gas Journal showed that it takes about 7 years, on average, for new workers to achieve a level of competency that permits them to assess risks and appropriately make decisions.[5] Not only is this figure is in direct conflict with the typical tenure of 5 years in one position meaning that the thinly spread skilled labor will be required to become senior staff before they are able to achieve competency in their current role, this also means that these millennials are not given the opportunity to become competent in their role before the retirement of the more experienced workforce."

Jan 1, 2016

By M. Misra

The coral contaminated with plutonium at Johnston Atoll UA) was subjected to gravity and flotation separation processes at the Soil Washing Laboratory (SWL) and also at the Johnston Atoll UA) site. Tests were conducted with the contaminated coral fractions referred to as the "HP-l" ( hot particles) and the "sludge". The gravity process tested was centrifugal gravity separation and the flotation processes were conventional Denver mechanical flotation and tall column flotation. Flotation tests were conducted using both fresh and sea water. Industrial fatty acid (anionic collector) was chosen as collector to make plutonium-enriched particles hydrophobic. The use of flurosilicic acid and sodium silicate made the clean coral hydrophilic. The results show that each of the processed when tested with appropriate size fraction and operating conditions resulted in passing the success criteria. It was possible to obtain more than 80% weight of the original coral as "clean sand" having activity below the JA site "soil screening level" of 13.5 pCi/gm. The field tests spiked with plutonium particles showed remarkable success. The effect of depressants, flotation medium and the coral pretreatmentis described. Finally, a flowsheet developed by the University of Nevada, Reno to treat 8000 tons of HP-l pile presently stored at JA is presented.

Jan 1, 1996

The concept of "classification is expanded beyond the performance of the classifying equipment to include all aspects of the fines removal system of the grinding circuit. Design and operating parameters which affect fines removal are identified and discussed, and a quantitative index for circuit fines removal effectiveness is defined. This approach lends new interpretation to certain observed phenomena, and suggests useful guidelines for circuit design and operation.

Jan 1, 1985