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By Allen Latham

It started' in 1936 when some Dutch adventurers wanted to scale the highest mountain in the South Pacific. Quite by accident, they discovered the Ertsberg, a contact deposit of magnetite laced with chalcopyrite, in a high mountain valley where it had been gouged at by glaciers and finally left as a solitary pillar for its discovery by a geologist who lent purpose to the expedition, Dr. J.J. Dozy. By the-.time a report was published describing the deposit, war had hit the Netherlands. Perhaps again by accident, the report was uncovered in 1959 by the East Borneo Company. At this point, Freeport entered the scene through its vice president for exploration, Forbes Wilson. During the course of a meeting on laterite prospects, the Ertsberg was introduced and he put the wheels into motion for Freeport to join in its exploration. You might, at this point, ask yourself whether you or your company would have taken on a venture to look at a reportedly large high grade copper outcrop in New Guinea, an unexplored land known best for its inhospitable climate, terrain and head-hunters. I heard the chief executive of one large mining company comment sometime back that neither he nor his company would have gotten involved. I won't attempt to describe the trials of the initial exploration expedition that passed through dense-man grove swamps, tropical jungle and across jagged mountains a distance of some 200 miles to get to the Ertsberg in 1960. It should be chronicled by its participants - Forbes Wilson, Del Flint, and John Bowenkamp. Needless to say, the participants relish the experience but wouldn't be among those volunteering for a return engagement. As a result, the Ertsberg changed from a reported outcrop to a mineral deposit containing an estimated 13 million tons with systematic surface sampling indicating a copper grade of over four percent. Moreover, the deposit extended to an indeterminate depth with the possibility of doubling or tripling. reserves well within reason.

Jan 1, 1971

By Nathaniel Arbiter, Robert R. Beebe

The U.S. mining industry - once world dominant and largely independent of foreign sources for most major commodities - has today lost this position, with little likelihood of regaining it. But even though Business foretold The Death of Mining four years ago, the current outlook is less pessimistic because of drastic restructuring of the industry; a major reduction in its labor force, with resulting large increases in productivity; and introduction of improved technology. In the face of this clearly changed climate for domestic mining, it is important to examine the role of the development and research establishment in the industry's future, which raises a complex set of questions: 1. Where and to what extent can new technology assist in the continued survival of the industry ? 2. What is the past record of the research establishment in developing new technology; and what is the industry's record in supporting and adopting it ? 3. In the light of these records, and of the drastic cuts in both research staffs and expenditures, what areas should be the most important targets for new technology? New Technology vs. Old A1 though mineral processing's origins can be traced back through five or six millennia, its modern structure is about 200 years old.

Jan 1, 1989

By Pier Francesco Paglini, Gian Luca Menchini, Pier Francesco Boschi

"PROJECTThe “Caltanissetta” Tunnel is part of the ANAS S.p.A (National Autonomous Roads Corporation) $ 1.3 Billion Highway 640 Caltanissetta-Agrigento (Sicily, Italy) Rehabilitation Project, consisting in upgrading of 62 km (40 miles) of highway. The Italian multinational construction company Cooperativa Muratori & Cementisti di Ravenna, is the General Contractor for the design and build contract. The highway S.S. 640 starts from Porto Empedocle, to the intersection with the Motorway A 19 Catania-Palermo.The entire project, double carriageway designed for speed 70-120 km/h and maximum longitudinal slope of 4.2%, is divided into two sections. First Section: just finished and opened to traffic. Second Section: mainly involving the province of Caltanissetta, length about 28 km (18 miles), works started in 2013. This second section includes the most challenging work of all the project, the “Caltanissetta” tunnel consisting of two separate tubes, each with 3.9 km length and inside diameter of 13.50 m, in order to host 2 traffic lines and an emergency line. HORIZONTAL AND VERTICAL ALIGNMENT - GEOLOGY AND HYDROGEOLOGYThe plan alignment of “Caltanissetta” tunnel is formed by two tubes which are located at a minimum mutual distance of 22 m to a maximum of 63 m, with n. 9 pedestrian and n. 4 road cross passages; ventilation shafts are not provided. Overburden over portals area is about 5 m till a maximum of 120 m. Tunnel sections have variable longitudinal slope from 2.6% to 0.5%, transversal slope of about 3.5%. Right tube length is 3,992 m, left tube length is 3,877 m."

Jan 1, 2016

By H Sohn, R. R. Fernández

Microscopic gold inclusions in sulfide minerals cannot typically be extracted by conventional cyanidation. The gold ore must be pretreated to oxidize sulfide minerals associated with gold and to remove other minerals and chemical compounds that interfere in the cyanidation leaching process. The recovery of gold from refractory sulfidic-carbonaceous ores after roasting pretreatment was studied. With the addition of an oxygen-containing gas (e.g., air or oxygen-enriched air), sulfides of iron, zinc. copper and other metals are tramformed into solid oxides or sulfates and gaseous sulfur dioxide at elevated temperatures (e.g., 400° to 800°C). When the sulfides are oxidized, individual particles lose internal volume and become porous, allowing leaching solutions access to the gold. The structural characteristics of the calcine have a strong influence on the eventual recovery of gold by cyanidation. These characteristics are strongly dependent on the roasting conditions and roasting method. The optimum combination of particle size, roasting temperature, reaction time and oxygen concentration in the off-gas was determined for a typical refractory sulfidic-carbonaceous ore from the Carlin Trend in Nevada. The tests were run using a 150-mm laboratory rotating tube furnace and 160- and 200-mm.fluid-bed pilot roasters. Laboratory results indicated that the maximum gold extraction was 92%, with the head and the leach residue containing 5.7 and 0.4 g/t (0.166 and 0.013 oz/st) Au, respectively. The maximum extraction was achieved under the following roasting conditions: a top particle size of 150 yin, a residence time of 2 hrs, a roasting temperature of 475°C and with 40% oxygen (by volume) in the off-gas. Similar results were obtained from circulating fluid bed (CFB) pilot-plant testing. The maximum gold extraction was 90%, with the head and leach residue containing of 5.1 and 0.5 g/t (0. 149 and 0.015 oz/st) Au, respective) v. These results were achieved with the same particle size and oxygen concentration as in the laboratory testing but with the roasting temperature of 500 ° to 525°C and a residence time of 30 min.

Jan 1, 2000

By P. Crouse, J. Obermeyer

"INTRODUCTION Site location and history The Holden Mine is a former underground copper mine that was developed and operated by the Howe Sound Mining Company (Howe Sound) from 1938 to 1957. The mine is located in north-central Washington State, U.S., near Lake Chelan in the area shown as Holden Village in Figure 1. Although Rio Tinto never owned or operated the mine, they are managing and funding a several hundred million dollar clean-up to prevent future water and soil contamination and to reclaim the former mine site under the United States Environmental Protection Agency (USEPA) Superfund process. The former mine included an onsite mill and a nearby housing complex for the miners. Howe Sound developed the mine as a series of near-horizontal drifts and tunnels, interspersed with stopes and shafts that connect different mine levels underground. The tunnels that were excavated to develop the mine total nearly 100 km in length.During development of the underground workings, Howe Sound removed more than 230,000 cubic meters (m3) of waste rock from the tunnels and deposited this material in two waste rock piles. Ore was processed from the mine in the onsite mill to produce a copper concentrate that was shipped off site for smelting. Roughly 10 million tonnes of tailings were produced as a by-product of the milling operation, most of which were deposited in three large impoundments (Tailings Piles 1, 2 and 3) directly south of and adjacent to Railroad Creek. Howe Sound closed the mine in 1957. In 1961, the property was transferred to Holden Village, Inc. (Holden Village), a not-for-profit corporation that maintains a year-round community and operates an interdenominational religious retreat in the former miners’ town. With the exception of the patented private land, the remainder of the Site is on National Forest lands and is administered by the U.S. Forest Service. The mine is remote. It is only accessible by boat or float plane from Chelan, Washington, up Lake Chelan to Lucerne, nearly 40 km. Vehicle access from Lucerne to the mine is provided through a 17.5-km-long winding gravel road that climbs 640 meters in elevation. The general site features are shown in Figure 2. Physical setting The Holden Mine is located on the eastern slopes of the Cascade Mountain Range at an elevation between 975 and 1,050 m above mean sea level. Holden Mine was developed adjacent to Railroad Creek, which lies in a glacial U-shaped valley carved into the igneous and metamorphic bedrock with steep-sided slopes (Figure 2)."

Jan 1, 2017

By L. S. Gertsch, M. Z. Abu Bakar

The research presented here is part of a project to quantify the differences in the mechanical excavatability of rocks in dry and water-saturated conditions. A series of full-scale laboratory linear rock cutting tests were carried out with a long-bladed single disc cutter on dry and water-saturated sandstone blocks. The muck collected from the cutting tests was analyzed to establish a link with the specific energy (SE) of the operation. The coarseness index (CI), a non-dimensional parameter, was found to be a useful indicator of the relative efficiency of the cutting operation. An inverse relationship of the form SE = k CI-n was observed between SE and CI. The power n of the relationship for both dry and saturated rock was much lower than found in previous studies. The exponent n is believed to be dependent on the strength of the rock and the cutter type used. Although the average CI was lower for saturated rock than for dry rock, at the same time, saturated rock cutting was found to be less energy-intensive (in terms of SE) than dry rock cutting. Moderate correlation exists between the production rate or yield and the SE of the cutting operation for both dry and saturated rock, which can provide some useful information about the field production rate, discounting the effect of discontinuities in the rock mass.

Jan 1, 2012

By Y. Guan

The dissolution behavior of silver in ammoniacal solutions with cupric ammine as an oxidant has been investigated using a rotating disc electrode. The rates of dissolution of silver were determined by an electrochemical means as well as a direct measurement of silver ions reported in the bulk solution as a function of time. The variables investigated included stirring speed, temperature, concentration of lixiviants, and pH of the solutions. The rate of dissolution under the conditions studied' was found to be controlled by an electrochemical reaction at the liquid/ solid interface with an apparent activation energy of 48.07 kJ /mole. The rate was found to be a half order with respect to the, concentration of cupric tetra-ammine, Cu(NH3)l+.; The results were explained in terms of a mixed' potential theory.

Jan 1, 1994

By J. C. Zelanko

The U. S. Bureau of Mines conducted a multi-faceted geomechanics research project at a bump-prone longwall coal mine in eastern Kentucky. This mine presented a unique opportunity to study coal mine bumps in that the problem appeared to be confined to areas beneath a sandstone channel of limited areal extent. The Bureau's research plan sought to exploit the uniqueness of the site by monitoring strata behavior and longwall support reactions as the longwall face approached and passed beneath a sandstone channel. The study incorporated static pillar stress and strata deformation measurements, shield support leg pressure measurements, and microseismic monitoring as well as geologic mapping and the collection of observational data. Data collection was underway when a major coal bump occurred on the longwall face at the mine. Pillar behavior (load and deformation), shield loading, and microseismic activity were monitored prior to, during, and after the bump. Observations in the tailgate indicated that these pillars were failing prior to and after the face bump. Shield load data which were evaluated in an effort to identify trends which could be used to forecast coal bumps appear to provide a measure of the effectiveness of destressing operations conducted on the face (e.g. shot firing). Analyses of microseismic data revealed anomalous values associated with microseismic "energy" prior to the face bump. In addition, microseismic source location data and underground observations provided some insight as to the sequence of pillar and face bumps.

Jan 1, 1991

By S. K. Kawatra, V. Claremboux, S. Valluri

Carbon dioxide capture from coal-fired power plant flue gas and subsequent sequestration is expected to play a vital role in mitigating global climate change. To meet the growing need for CO2 capture Technology, Michigan Technological University is researching CO2 capture and Utilization. We have successfully converted CO2 into oxalic acid using an electrochemical approach. If oxalic acid can be produced in bulk from CO2, it can be used to leach rare earth minerals at low cost. Electrochemical reduction of CO2 to hydrocarbons and other chemicals is a complex multistep reaction with adsorbed intermediates. The exact reaction mechanisms leading to various products are not clear from the literature to date and will likely change over the range of conditions like pH, electrode potential, electrolyte medium, catalyst, etc. In this paper, we will present an idea of how the factors mentioned above will effect the electrochemical reduction of CO2 to Oxalic acid. INTRODUCTION. CO2 is thermodynamically quite stable, as shown by its highly negative heat of formation. Thus, it is expected that the formation of any useful chemical from CO2 will require the input of at least as much energy as geological sequestration. However, to be more effective the resulting economic value of the chemical need only pass the cost of the additional energy required beyond geological sequestration. This lends itself to two extremes: one where the quantity of energy required is low and one where the economic value of the additional energy is low. It is expected that CO2 can be reduced via electrolysis to several compounds. Of particular interest are formic acid, oxalic acid, methanol, ethanol, formaldehyde, and carbon monoxide (as a component to syn-gas). These chemicals have been reported as electrolytic products previously in literature and have considerable potential for application. EXPERIMENTAL Electrocatalytic Production of Oxalate from CO2 We are using membrane electrolysis cell to produce oxalate from CO2. A membrane electrolysis cell is a 2-chamber electrolysis cell where the chambers are separated by a selectively permeable membrane. To produce oxalate, a cation exchange membrane (which selectively exchanges cations) was used. Previous literature suggests that in the cathode chamber an organic electrolyte, such as tetraethylammonium perchlorate or tetraethylammonium bromide in dimethylformamide, are preferred3. In the anode chamber, a sodium hydroxide solution water is used. Carbon dioxide is then bubbled into the cathode chamber as a current is applied.

Jan 1, 2019

By C. Sunderman, R. Jacksha

"Mine monitoring through various sensors is a vital component of successful miner safety and health programs. Data from environmental, geotechnical, infrastructure and other types of sensors are increasingly used to discover and mitigate health and safety concerns in underground mines. In many smaller underground mines, as well as in the new development headings of larger underground mines, leaky feeder communication systems may be the only available means to transport crucial monitoring data. In addition, data transport is increasingly being delivered using Internet Protocol (IP), while older forms of serial communication are being retired. This paper presents the selection, configuration and testing methodologies employed by researchers from the U.S. National Institute for Occupational Safety and Health (NIOSH) to integrate commercially available land mobile data radios into an existing leaky feeder communication system to provide IP data transport.IntroductionTo enhance the health and safety of their mining workforce, mine owners and operators are increasingly installing environmental monitoring and control systems in underground mines. Real-time, mine-wide monitoring is becoming a reality with the implementation of the Industrial Internet of Things (IIoT) into the underground mining industry (Zhou et al., 2017). However, not all underground mines, especially smaller mines and new development headings in larger mines, have the information technology infrastructure in place to handle the data transport requirements for the newer Internet Protocol (IP)-based technologies that are part of IIoT.This was the case with a mine in the Western United States. It lacked the infrastructure to perform critical monitoring in remote headings. Therefore, the mine partnered with the U.S. National Institute for Occupational Safety and Health’s (NIOSH) Spokane Mining Research Division (SMRD) to develop and evaluate a cost-effective solution for the real-time monitoring of geotechnical conditions in relatively remote sections of the mine. This paper describes SMRD’s solution to leverage the mine’s existing leaky feeder communications system to achieve IP data transport using commercially available land mobile data radios (NIOSH, 2013; Forooshani et al., 2013; Novak, Snyder and Kohler, 2010; Yarkan et al., 2009). The solution, fully evaluated in laboratory and mine environments, requires no modifications to the existing system, is economical, simple to implement, and reliable. It also allows for transition to higher-bandwidth IT networks, such as fiber optic or WiFi, should they become available."

Dec 1, 2018

By Ross Glanville

The Optimum Production Rate (OPR) is one of the most important parameters in the evaluation of a mineral deposit. The OPR cam also be expressed as the Optimum Mime Life (OML) in years since the expected mime life is determined by dividing the OPR per year into the estimated ore reserves. Unfortunately, very little time and effort has been directed towards the determination of the OPR. Instead, "rules of thumb" are often applied to select a mime life without due consideration of the economic implications of such a selection. A "justification" for a particular production rate is often based on a pre-conceived arbitrary requirement for a mime life of 5, 10, or 15 years, for example. In this paper it is demonstrated that such arbitrary selections for high-grade/low¬-tonnage mines (such as many underground gold/silver deposits) often lead to sub¬optimal results. In fact, am apparently uneconomic deposit at am arbitrary production rate may be economic at the OPR. Consequently, investment opportunities may be overlooked if one analyzes mime' properties based on arbitrary production rates.

Jan 1, 1984

By Robert E. Kirby

The potash mine and refinery of AMAX Chemical Corporation is located 26 miles east of Carlsbad on the north end of the potash producing areas. This property was developed between 1949-1952 and production of muriate began in August 1952. Two shafts, located 400 feet apart, were sunk to the ore zone 900 feet below the surface. A 15-foot diameter ore hoisting shaft equipped with a 1000-ton ore pocket, crusher and automatic skip loading equipment plus a 20-foot diameter service shaft with a curtain wall for exhausting air were provided. Sylvinite production to date has been from the first ore zone, stratigraphically, the lowest of ten identified mineralized zones in the salt section. This first ore zone has been the top producer of Muriate of Potash over the years. In our area we do have some very marginal mineralization in the third ore zone some 35 feet above the first. We have not mined from this seam as yet but we are investigating the economics very closely with access slopes and an experimental mining panel. Our ore seam is generally flat lying but does have local gentle rolling with grades from 2% to 5%. The mine was designed and developed from the beginning with conventional mining practices and rail haulage from the mining section to the ore pocket. As mining progressed in the early years, production increased from less than one million tons annually to a maximum of 3,935,000 tons in 1964. Efficiency also kept pace with the increasing production and continually improved until the efficiency of the production crews reached an average of 100.3 tons per manshift in 1964.

Jan 1, 1974

By G. C. Kachel

Significant effort has been expended and considerable success has been realized m the application of instrumentation and automatic control equipment in the mining and ore processing industries. This effort has been applied principally to process equipment with the objective of increasing throughput, minimizing labor requirements and/or improving grade or product quality. Less spectacular, but quite rewarding has been the successful application of instrumentation and automatic control equipment to a wide variety of material handling equipments. This paper describes some of this work including: (1) automatic weighment of load-haul-dump units and trams underground; (2) automation of skip loading; (3) instrumentation applied in feeders and conveyors; (4) level measurement in bins, silos, vessels and sumps; (5) automatic blending of sized materials; (6) automatic loading of ships, trains and trucks; (7) automatic control of tailings disposal facilities

Jan 1, 1973

By F. Habashi

Japan was a closed society until 1853 when it was forced to open to the West. Mining, metallurgical, and geological education started there around 1861 when a graduate from Yale University in USA went to Japan to organize the first School of Mines. This was followed by other metallurgists from Great Britain, France, and Germany and thousands from other disciplines. The present report is a summary of the writer's first contact with Japanese metallurgists and his visits to a number of universities and research institutions in the past years.

Jan 1, 2012

By K. P. Stricker, H. Keddeinis, K. Grebe

Recent investigations by Mannesmann Research have shown that disintegration of sinter with widely varying quality levels is subject to a much more complex set of influences than was previously assumed. It was confirmed that disintegration at temperatures between 300° and 600°C (570° and 1,110°F) is triggered by the degradation of hematite. The specific tendency of hematite to disintegrate is, however, not constant: sinters containing the same amount of hematite can show widely differing disintegration tendencies, depending on structural homogeneity, porosity, and gangue quantity. Sinters with heterogeneous structures transmit stress to the hematite phase and this favors disintegration. Another factor is the brittleness of the glassy silicate phase, which can be influenced even by small modifications of minor gangue constituents.

Jan 2, 1984

By James G. Mock

The choice of equipment to be applied to a given installation by the Application Engineer begins with the data as presented to him by the user. This point in the relationship establishes a communication link, which will decide whether or not the correct piece of Overhead Equipment is applied at the most economic advantage to the user. The role played by the user cannot be minimized. No one knows better than he, just what work he expects to accomplish with this piece of machinery. However, all too often, he oversimplifies the requirements, and along with minimal crane and building parameters, merely refers to one of the following crane classifications as defined by The Crane Manufacturing Association of America, as shown in Figures 1, 2, 3, 4, 5, 6 and 7. This approach places the ultimate user in an unfair position, since he has then assumed the status of the machinery designer and must, therefore, assume the responsibility of the success or failure of the operation of that piece of machinery. If the user selects a Class "C" crane for his job requirement, when actually a Class "B" crane can adequately handle the work load, he is not offering the most economic solution to his company and added little to the cranes service capabilities.

Jan 1, 1973

By Barrie C. Butt

The opportunity for an exploration geologist to follow a successful exploration project through the feasibility, financing, construction, development and exploitation phase is rare. In addition, it is not often that the exploration geologist can be present during the mining of a deposit to explain why certain actions were taken or interpretations made and to find out how these interpretations turned out in actuality. At the Woodsreef chrysotile asbestos mine in New South Wales, Australia, mining has been in progress for six years and the writer has been intimately associated with the project during the five years of exploration and the six years of exploitation. The industry is possibly aware of the fact that the Woodsreef Mine has had major production problems, the majority of which have stemmed from the unique characteristics of the ore body and of the fibre. Because of these unique features, a large volume of research has been undertaken by Woodsreef and by other scientific organisations in Australia, England and Canada on the Woodsreef fibre. The answers to some of the problems have negated some semi-sacred concepts of asbestos ore milling and led to the development of new techniques, such as the adoption of microscopic fibre counts as a routine procedure; the modification of accepted evaluation procedures; the development of new machines for dedusting fibres, and to the recognition of a fibre with a unique milling behaviour pattern and, possibly, properties. The problems experienced can be divided broadly into those associated with the geology and those associated with the physical properties of the fibre. It is possible that the same features may manifest themselves in other deposits around the world, and if they can be recognised during the exploration stages a feasibility evaluation may be just that little closer to the actual.

Jan 1, 1978

By Mark Van Dyke, Mark Mazzella, Gamal Rashed, Nicole Evanek, Brent Slaker

In the past decade, there have been several incidents of massive ground collapses in underground stone mines in the eastern United States. Fortunately, these events have not resulted in any fatalities. However, three mine workers were injured and many others were at risk due to the hazard from the fall of ground and/or the airblast associated with these massive collapses. The National Institute for Occupational Safety and Health (NIOSH) initiated a project to better understand the causes of these massive ground collapses to help prevent their future occurrence. The main objective of this study is to investigate the main factor(s)that initiated one of these massive ground collapses. The authors relied on several tools including three-dimensional (3-D) LiDAR scans for the surface subsidence feature and the underground mine workings around the collapsed area, borescope data at multiple locations around the collapse, S-Pillar analysis for average and unfavorable conditions, and numerical models. The emphasis has been placed on the impact of the following limestone pillar stability parameters: pillar width-to-height (W/H) ratio, benching, the existence of karst features, weak roof, and geological discontinuities. 3-D LiDAR scans were utilized to show the shape and the extent of karst cavities observed within stable pillars around the perimeter of the collapsed area. Together, this coupling of field measurements and observations and modeled systems suggests the potential causes of the collapse.

Jul 1, 2023

By Mirko Martini, Marcelo Benaglia, Andrea Codalli

Riachuelo Lot 3 forms part of a sanitation programme being implemented in Argentina to relieve the Riachuelo river basin from its current contamination. The programme, by far the most important in its kind in the country during the last decades, will expand the sewage capacity of Buenos Aires and will benefit an area of 4.3 millions inhabitants by intercepting a number of waste water discharges and conveying them to a new treatment plant prior to final discharge into the Rio de la Plata. The project foresees amongst other works the construction of an onshore 48 m deep shaft at the outlet of the treatment plant plus a 4,3 m inner diameter outfall tunnel of 12 km length. The last 1.5 km of the alignment is fitted with 34 vertical risers jacked from inside the tunnel to allow the discharge and dilution of the treated effluent into the Rio de la Plata. This paper describes the peculiarities and challenges, both in terms of design and in terms of construction, of the outfall tunnel, which was entirely bored under the Rio de la Plata using a 5.2 m cut diameter Tunnel Boring Machine (TBM). On one hand, the tunnel segmental lining was designed to work in tension during the system flow rate peaks while on the other the tunnel excavation faced a variety of complex conditions, such as crossing water bearing permeable soft ground formations and advancing at face pressures in excess of 3,5 bars for the entire route.

Jun 13, 2021

Microorganisms have been widely used for hydrometallurgical operation and effluent treatments(Smith, et. al., 1991a; Gadd, et. al., 1986; Darnall, 1986; Paponettis, et. al., 1991; Mihaylov, et. al., 1991; Rusin, et. al., 1991; Noble, et. al., 1991; Yang, et. al., 1991). In recent years there is a growing interest in using microorganism for flocculation of minerals fines and flotation collector (Smith, et. al., 1991b, 1991c; Misra, et. al., 1991a, 1991b, 1992a, 1992b). It is envisioned that the utilization of nonpathogenic microorganism and/or extracellular surfactant derived from microorganism as a flotation collector will replace some of the environmentally toxic flotation collectors and at the sometime improve flotation efficiency. The selection screening, and judicious selection of appropriate microorganism as flotation collector has been a challenge to process engineers. Over the past five years, continued research at the University of Nevada has shown that certain microorganism Mycobacterium phlei (M. phlei) can be a good flocculating agent and has potential to be used as a flotation collector (Dubel, et. al., 1992; Misra, et. al., 1991a, 1991b, 1992a, 1992b; Smith, et. al., 1991d; Chen, et. al., 1992a, 1992b)).

Jan 1, 1993