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By Norman J. Sather

LOCATION AND HISTORY The Bunker Hill Mine is situated on the south side of the Coeur d’Alene River in Shoshone County of Northern Idaho near the City of Kellogg. Kellogg, the largest in the Coeur d’Alene District cities, is at an elevation of 2,300 feet and has a population of approximately 7,000 people. It can be reached by air, railway or highway. The history of the Bunker Hill Mine dates back to August 26, 1885, when Noah S . Kellogg found the outcrop of the Bunker Hill ore body on the hillside above the present town of Wardner, Idaho, in Milo Gulch. A small concentrator was erected in 1886. Before the railroad came, the mine output was transported by mule teams to the head of navigation on Coeur d’Alene Lake. After ten years of production, an interest was purchased in the Tacoma Smelter at Tacoma, Washington, to which the entire output was shipped. In 1916 and 1917 a modern lead smelting plant and refinery was erected and in 1927 and 1928, a modern Electrolytic Zinc Reduction Plant was built and put into operation by the Sullivan Mining Company which was 50% owned and now totally owned by The Bunker Hill Company. GEOLOGY AND MINERALOGY The Bunker Hill ore bodies are found in gray and greenish gray quartzite and argillaceous quartzite of Precambrian age and are known as the Revett and St. Regis formations. Most of the ore bodies are found in the St. Regis formation.

Jan 1, 1970

By J. Juilland

Over 10 percent of the United States of America or 41 percent of the Federal lands is managed by the Bureau of Land Management (BLM) as Public Lands. The mission is to manage the use of these lands and their resources. The way in which BLM carries out its mission is being refocused under the concepts of biodiversity and ecosystem-based management for the benefit of various human needs including environmental, social and economic values. The Bureau is developing methods to integrate the renewable and non-renewable resources programs into the concepts of biodiversity and ecosystem-based management. Exploration, development and extraction of energy or mineral resources on Public Lands are affected. The statements that following the next few pages are my personal views as a scientist (economic geologist -mining technologist) who is and has been involved for the last twenty years in the multiple-use management of Public Lands. They are not necessarily the position of the Bureau of Land Management, although much of the information on which I base my views comes from my experience with the BLM. The Bureau of Land Management (BLM) manages over 10 percent of the United States (270 million acres or 108 million hectares) which is 41 percent of the Federal Lands. Lands managed by BLM are known as Public Lands as opposed to the National Forest Lands which are Federal Land Policy and Management Act (FLPMA) of 1976 which in Sec. 102 states ??that it is the policy of the United States (7) ?that management be on the basis of multiple use and sustained yield??, the mission of the BLM is rapidly refocused under the concepts of biodiversity, ecosystems, and ecosystems-based management for the benefit of the environment, human needs and socio-economic values.

Jan 1, 1994

By R. J. Craig

Introduction All mining operations produce rock dust. Inhalation of rock dust, particularly if it has a high silica content, causes silicosis. Silicosis is, therefore, recognized as a hazard of the mining industry and has been made compensable throughout most of Canada. Most of the dust in any mining operation is caused by rock drilling and blasting operations and the movement and transportation of broken rock. Dust from blasting cannot be eliminated, but it can be controlled by means of increased ventilation, the use of water sprays, and the control of blasting hours. Dust from ore movement can be reduced by keeping the broken rock in a moist condition at all times. The dust from the rock drilling operation has been found to be the most difficult to control. Concentrations of dust caused by rock drills in stopes can usually be reduced to the safe minimum of 300 particles per cubic centimeter (p.p.c.c.) by diluting the air with increased ventilation. In development headings, where the machines are more confined, this is not always practicable. Therefore, the dust must be eliminated at its source. This paper deals with the reduction of dust from Leyner machines by adopting improved designs.

Jan 1, 1947

PUGET SOUND SECTION SIMON H. ASH, Chairman, I. F. LAUCKS, Vice-Chairman, CHARLES SIMENSTAD, Sec.-Treas., 425 Lyon Building, Seattle, Wash. GLENVILLE A. COLLINS, JOHN N. POTT. The Puget Sound Section met at the Arctic Club, Oct. 28, 1916, for the annual meeting. Those present were: Chairman Glenville A. Collins, Vice-Chairman H. L. Manley, Sec.-Treas. Amos Slater, Chester F. Lee, R. P. Tarr, G. E. Rockefeller, Simon Ash, Geo. W. Evans, Joseph Daniels, I. F. Laucks, F. C. Greene, Darsie C. Bard, Marcel Daly, Milnor Roberts, F. A. Hill, Percy E. Wright, and as guest, Mr. Coates of British Columbia. After dinner had been served, Chairman Collins called the meeting to order. The reading of the minutes of the last meeting were suspended upon request of the Secretary. The Secretary read the report from the Committee on the Associated Engineering Societies of Seattle. Upon motion, duly seconded, the report was adopted and placed on file. Mr. Lee, Chairman of the Committee. on the Mining Men's Convention to be held this coming winter, gave his report orally, and upon motion the committee was continued. The report of the Secretary-Treasurer was read, received, and placed on file.

Jan 3, 1917

By Nikhil Dhawan, SHAILA MIR

The emerging problem of electronic waste has promoted the interest in exploring metal recovery from secondary sources under the umbrella of urban mining. This study presents the physical and chemical characterization of various components present in end-of-life laptops to help ascertain the sites of metallic values and develop sustainable and environment-friendly recycling. The recycling potential of a laptop is evaluated by sequential disassembly, separation, and characterization of components such as body (49.8 wt.%), printed circuit board (9.7 wt.%), hard disk drive (4.9 wt.%), and battery (12.4 wt.%). The printed circuit boards comprise metallic values, majorly copper (25 wt.%), tin (5.8 wt.%), and lead (3.1 wt.%). The precious metals (Au, Ag) with an economic advantage are abundantly present in electronic components such as integrated circuits, capacitors, resistors, and processors. Critical elements such as lithium, cobalt, and rare earth elements are detected in the discarded laptops' batteries and hard disk drives. The recycling potential representing the amount of material that can be recycled in various components, depending on the type, concentration, and purity, is determined in the range of 36–100%. On average, a unit laptop contains~ 386 g of Cu (14.45 wt. %), 49.73 g Co (1.86 wt. %), ~346 mg Ag, ~141.2 mg Au, ~650 mg of rare earth elements (Nd, Dy). This study presents a database for investigating integrated and economical recycling techniques from different components of a laptop, and an overall process flow is also proposed.

Jul 24, 2021

By Johannes Käppeler, Alexander Weh, Harald Giese, Klaas van der Wielen

"High voltage breakage is a novel comminution technology that shows considerable potential for various applications in mineral processing and recycling. It relies on highly energetic electrical pulses to induce electrical explosions in rocks, causing the formation of plasma channels and powerful shockwaves that result in fracturing and fragmentation of particles. There has been considerable interest in this technology for its ability to weaken rocks and preferentially liberate target minerals, as previously demonstrated by other authors. Weakening has the potential to significantly reduce energy consumption during comminution, or alternatively, increase throughput of a circuit. Better liberation may yield an improved concentrate grade and/or recovery, reduce fines losses to tailings or increase the grind size required for liberation, thereby also reducing energy requirements. This review aims to increase general awareness of this technology, and promote further research into it by providing a general summary of the theory underlying high voltage breakage, as well as the envisaged applications of this novel technology. A brief history of the technology is presented before progressing onto the physics underlying the electrical and geomechanical aspects of high voltage breakage. Key results regarding weakening and liberation are discussed, and some mention is made of current challenges and planned developments to increase the throughput of high voltage breakage units to the level where it can be integrated into new and existing processing circuits."

Jan 1, 2014

By David B. McWhorter

Conventional analyses of seepage through saturated media do not apply when tailings impoundments are located above a partially saturated zone. Three stages of seepage are identified and methods for estimating the seepage rates and duration of each stage, based upon flow in partially saturated and saturated porous media, are demonstrated. The effectiveness of earthen liners is discussed and procedures for estimating the required properties of the porous media are provided.

Jan 1, 1978

By D G. Oldfield

Pall has developed and supplied to several airlines cabin air libers to provide clean air for passengers and crew in flight, while reducing airline operating costs. Most of today's modern commercial passenger aircrafts employ cabin air recirculation as a means of reducing operating costs. With large numbers of passengers being subject to an increasing proportion of recirculated air for hours at a time, the matter of cabin air quality, with particular respect to the health effects on passengers and crew, has to be addressed. Commercial pressure will ensure that the airlines and aircraft manufacturers will not revert back to the total fresh air systems of the 1960s and 1970s. In fact, feasibility studies are already being undertaken to look at increasing the proportion of recirculated air to 80% and above. With the application of specialist nitration technologies. Pall is able to ensure that the requirements for economy are met whilst ensuring that the air is effectively rendered as 'fresh air’ each time it is recirculated.

Jan 9, 1996

The thirty-ninth meeting of the Boston Section was held at the Engi- neers? Club on Monday evening, Dec. 4, 1916. Thirty-three members and guests sat down to dinner; There were present as section guests; Dr. L. D. Ricketts, and Prof. Bradley Stoughton, President and Secretary of the parent society, and each was called upon to speak. Mr. Stoughton spoke of the growth of the Institute during the past year and described the very numerous and important activities, of which the junction of the American Society of Civil Engineers with the other three societies is perhaps the most important. Dr. Ricketts, the advertised speaker of the evening, spoke on Recent Progress in Mining and Metallurgy of Copper Ores. In discussing the improvements in mining, he traced the mining methods from square- set mining to the modified Ohio System now so successfully used at Inspiration: In metallurgy, he described the growth of reverberatory-smelting ant1 allied problems such as the utilization of the waste heat for generating steam. He laid stress on the importance of sampling and bedding of

Jan 6, 1917

BOSTON SECTION ALFRED C. LANE, Chairman, GEORGE A. PACKARD, Vice-chairman, E. E. BUGBEE, Sec'y-Treas., Mass. Inst. of Technology, Cambridge, Mass. R. L. AGASSIZ, FRED W. DENTON. Forty-sixth Meeting The forty-sixth meeting of the Boston section was held at the University Club on Monday evening, Jan. 28, 1918. Thirty-six members and guests were present, which is a record for this Section. After a good dinner, President Philip N. Moore, of the Institute, was introduced, and spoke of the many problems of the Institute. The topics covered were the progress and growth of the Institute during the administrative year, the efforts to stimulate the local sections and to bring them more in touch with the policies and problems of the parent body and, last but not least, of the constructive results and patriotic work of the Institute in the national service of the war. The other guest of the Section, Mr. Thomas Nelson Perkins, Counsel for the Priority Board, spoke most entertainingly of recent experiences in Russia, England and France. After considerable discussion during which Mr. Perkins most obligingly answered innumerable questions, the meeting adjourned at about 10 p. m.

Jan 7, 1918

By L. J. Buter, D. J. Collins

Introduction FMC's Paradise Peak gold mine was discovered by staff geologists in July 1983. Located south of Gabbs, in western Nevada, the deposit contains about 11 Mt (12 million st) of ore grading at 3.6 g/t (0.105 oz per st) of gold and 129 g/t (3.75 oz per st) silver. It is estimated that the ore contains 34 t (1.1 million oz) of recoverable gold and 933 t (30 million oz) of recoverable silver. The 3.6 kt/d (4000 stpd) mill began operation April 14, 1986, just 18 months after Davy McKee completed a feasibility study and construction, and two-and-a-months ahead of schedule. It also came in about 10% under budget at a cost of about $100 million. Crushing Run-of-mine ore is delivered from the mine in 45-t (50-st) haul trucks to a 272-kt (300,000-st) capacity open air stockpile. Ore is reclaimed using 5 m3 (7 cu yd) front-end loaders that feed a 91-t (100-st) hopper equipped with a 610- x 610-mm (24- x 24-in.) grizzly. A 1.4- x 11-m (54-in. x 35-ft) apron feeder delivers ore from the hopper by way of a vibrating grizzly screen with 127 mm (5 in.) openings to a 1- x 1.3-m (43- x 51-in.) Rexnord jaw crusher. Crushed material is conveyed to a 1.8- x 4-m (6- x 14-ft) Link Belt vibrating screen equipped with a 50-mm (2-in.) manganese grizzly bar deck. Screen oversize is fed to a 1.7/0.6-m (5.5 ft) Rexnord standard cone crusher. Product from this crusher joins the -50 mm (-2 in.) screen undersize and is conveyed to a 136-t (150-st) surge bin. Three hydraulically driven belt feeders deliver ore from the ore bin to three 2 x 6 m (7 x 20 ft) Link Belt single-deck tertiary screens fitted with 6 x 25 mm (0.25 x 1 in.) slotted polyethylene screens. Screen undersize - -6 mm (-0.25 in.) rock - is conveyed to a 3.6-kt (4000-st) ore storage bin. Screen oversize is delivered by way of a conveyor to a 91-t (100-st) surge bin. From this bin, two belt feeders feed ore to two 1.7 m (66 in.) Rexnord Gyradisc crushers, which are in closed circuit with the tertiary screens. Design features include magnetic protection for tramp iron removal and sloping floors and pump sumps for ease of clean up. Dust scrubbers keep the working environment clean and in compliance with state dust emission regulations. Grinding Two 1 x 4.5 m (3.5 x 15 ft) belt feeders deliver ore from the fine ore bin to a conveyor belt that feeds it to the 5 x 7 m (16 x 22 ft) Allis-Chalmers ball mill. The conveyor belt is equipped with a Merrick weightometer. This controls feed rate to the ball mill by speed control on the hydraulic motors driving the feeders. The 2.6 MW (3500 hp) powered mill grinds 3.6 kt/a (4000 stpd) to an average grind of 85% -75 µm (-200 mesh). The mill is in closed circuit with four 660 mm (26 in.) Krebs cyclones. Three of these are normally in operation while one is a standby. Warman pumps feed the cyclones through a cyclone distribution manifold. The cyclone underflow returns to the ball mill, which has a 300% average circulating load. Mill discharge pH is 11, and that is obtained through pebble lime addition to the feed belt. Cyclone overflow is sampled using a Heath & Sherwood two-stage sampler. It then flows to a 27-m-diam (90-ft-diam) Eimco thickener. Thickener overflow is returned to the grinding circuit, while underflow at 50% solids is pumped to the leaching circuit. Grinding-circuit design features include a steeply sloped floor for ease of clean up, an open area over the pumps for maintenance accessibility, and a ball hopper with a self discharge bottom to speed ball addition. Other features include a mill liner handler and an air clutch that connects the mill motor to the mill.

Jan 12, 1986

"The most common comminution testing methods and the associated analytical procedures provide average values and do not capture the variability in breakage behaviour of ore particles. Therefore, plant designs and process performance predictions use only average values; hence, the inherent variability that exists within an ore domain translates into variation in process performance. This paper discusses the drawbacks of using the average approach to impact comminution testing and plant design. It considers breakage intensity from a single-particle testing perspective. To clearly delineate breakage behaviour of each broken particle, an experimental technique using the JK Drop Weight Tester (JKDWT) has been developed by which actual comminution energy per particle and breakage intensities were measured directly. Four different ore types in ranges of -45+37.5mm and -22.4+19mm were tested at three energy levels of 0.1, 0.25, 0.5 kWh/t and six energy levels of 0.5, 1.0, 2.0, 2.5, 3.0 and 4.0 kWh/t, respectively. Sieved results of individual particles, notionally, t5, t10 and t50 showed the presence of large variability in their breakage behaviour, which was not captured by the standard JK impact breakage testing approach. In addition, the original JKMRC model is modified by introducing a third parameter, ‘Emint10’ which describes the minimum energy required to produce the minimum percent t10 for a given ore type and its significance is tested statistically. These results suggest that the analysis of breakage variability may lead to more robust plant designs. Perhaps, the most useful insight from this work is to extend single particle breakage model developed by JKMRC to a comminution percentile envelope which may provide a more detailed picture of ore breakage variability. INTRODUCTION Rock consists of mineral grains, pores, voids and cracks that may differ markedly in size/density which make rock a heterogeneous material by nature. The degree of heterogeneity in rock affects its breakage characteristics where these variations increase local differential strain and stress within a stressed rock (Scholz, 1968) and it depends on many factors such as rock genesis, alterations, etc. One important aspect of this heterogeneous feature is presence of a large amount of experimental scatter in rock breakage results when considered from a quantitative perspective (Bieniawski, 1967; Liu, Roquete, Kou, & Lindqvist, 2004)."

Jan 1, 2018

Diesel engines are used in underground mining 1 throughout the world. Exhaust gases from those engines contain toxic components. To protect quality in underground mines, diesel emission control was introduced decades ago, many years before the first surface applications. Today, emission controls, such as catalytic converters, are standard on underground diesel engines in countries concerned with occupational safety and health. Nett Technologies manufactures a range of diesel emission-control devices for underground mining. Emission problems are not the same at each mining operation. And there is no universal control technology. The selection of exhaust aftertreatment technology depends on raw exhaust emissions, particular emission problems, fuel quality and economics. Some of the technologies that have been used in underground mining to control diesel emissions include catalytic converters, diesel filters, fume diluters and water scrubbers. Table 1 compares the effectiveness of these technologies to control the particular components or aspects of diesel emissions.

Jan 1, 1997

NEVADA SECTION J. W. HUTCHINSON, Chairman, FRANCIS CHURCH LINCOLN, Vice-Chairman, HENRY M. RIVES, Secretary-Treasurer, Reno, Nevada W. H. BLACKBURN, E. A. JULIAN, EMMET D. BOYLE, JOHN G. KIRCHEN, FREDERICK BRADSHAW, C. B. LAKENAN, TASKER L. ODDIE. The formation of the Nevada Section was originally suggested by Professor F. C. Lincoln, who had discussed the subject with Mr. William L. Saunders when the latter was President of the Institute. Professor Lincoln sought the assistance of the Nevada Mine Operators' Association, whose Executive Committee constituted itself a Committee on Organization, and authority for the establishment of a Nevada Section to include the entire State was secured from the Board of Directors of the Institute. The formal installation took place at 10 A.M. on May 18, Mr. William L. Saunders officiating. The Honorable Emmet D.. Boyle, Governor of Nevada (and a member of the Nevada Section), made the address of welcome. On the afternoon of the same day, a technical session was held, at which the following papers were presented: History and Development of the Cyanide Process Charles Butters Virginia City Whitman Symmes Ore Deposition at Steamboat Springs Prof. J. C. Jones

Jan 7, 1916

SAN FRANCISCO SECTION W. H. SHOCKLEY, Chairman, PRANK H. PROBERT, Vice-Chairman, T. A. RICHARD, Sec.-Treas., 420 Market St., San Francisco, Cal. C. C. BRAYTON, J. F. NEWSOM. The San Francisco Section met on September 11 to discuss the problem of Labor in its Relation to the Mining Engineer. Mr. W. H. Shockley was in the chair. T. A. Rickard opened the discussion under four heads: The recognition of the union, the rustling-card, the sliding scale of wages, and the' contract system. He expressed his belief that collective bargaining cannot be ignored, and insisted that the mining company represented a collective bargaining of its shareholders with the men. employed in its mine. He held that the contract system was often used unfairly, but that used fairly it was the best check on labor tyranny. The rustling-card he held to be right in principle, in so far as it gave the employer the choice of employees, but he believed that it was often used in an irritating way to black-list refractory laborers. The sliding scale of wages was easy to establish in prosperous times, but it would inevitably lead to trouble when conditions went against the miner. His conclusion was that the quarrels of labor and capital were due mainly to a lack of the sense of fair play and of social justice. Albert Burch agreed with most of the foregoing, and insisted that 90 per cent. of the men were inclined to be just, but that the 10 per cent: made all the trouble. He stated that he had introduced the rustling-card in the Coeur d'Alene in 1899, as a means for getting rid of agitators. E. L. Foucar considered that labor was irresponsible. He described his experience in Peru, where the authorities promptly stopped a strike of Italian miners by threatening prompt punishment for any display of violence. Morton Webber also gave a bit of his own experience, to show that the chief trouble is that the men do not think for themselves, and are therefore easily led by fomenters of trouble. F. H. Probert described his experiences in Germany and. also in Arizona, and insisted that too often the men were not given a fair hearing. E. T. Blake argued that a manager must get the workmen's point of view, in order to control them effectively. He believed that young men who started life doing manual labor were in a better position to understand their fellow workers. George J. Young suggested that the mine owners should encourage the good men to lead the unions, and not leave the direction of the unions to the noisy element.

Jan 12, 1917

BOSTON LOCAL SECTION Executive Committee HENRY L. SMYTH, Chairman ALFRED C. LANE, Vice-Chairman AUGUSTUS H. EUSTIS, Secretary-Treasurer, 131 State St., Boston, Mass. ROBERT H. RICHARDS ALBERT SAUVEUR Meets on the first Monday evening of each winter month Twenty-first Meeting The Twenty-first meeting of the Boston. Local Section of the Institute was held at the Engineers' Club, 2 Comonwealth Avenue, Boston, Monday evening, Oct. 5, 1914. Twenty members and two guests were present. The Chairman, Henry L. Smyth, presided at the dinner, at the close of which he introduced, as the speaker of the evening, John M. Longyear, who gave a most interesting talk about his work in exploring for coal on the islands of Spitzbergen, 400 miles north of the North Cape of Norway. The talk was illustrated with many photographs, which showed clearly the nature of the work and the extraordinary difficulties of the location. AUGUSTUS H. EUSTIS, Secretary.

Jan 12, 1914

By G N. Phillips

No new goldfields have been found in the Witwatersrand Basin for over 60 years, and one consequence of this is a long-term decline in gold production. Exploration throughout this period has been based on the placer model that infers alluvial transport of gold grains and then sedimentary sorting in the basin; however, there is no viable source for so much alluvial gold and no single sedimentary setting that hosts the gold.An alternative genetic model can now provide a quantified explanation for the source of the gold, and it does not rely on alluvial gold processes. The hydrothermal model can easily explain the source of the Witwatersrand gold as being derived from the background gold at parts per billion (ppb) level throughout the Kaapvaal craton of South Africa. This gold is involved in metamorphic processes, available for solution in metamorphic fluids, and hence may be transported whilst dissolved in fluid into the Witwatersrand Basin. The hydrothermal model warrants consideration as it can explain the source of gold, the large alteration halo in the goldfields, the mineralogy, and especially the gold-carbon association.Working on the premise that if one model (placer) is not giving the desired results (discovery of new goldfields), then it may be prudent to consider alternatives. Application of a hydrothermal model to guide exploration would place importance on large and small early structures in and around the Witwatersrand Basin; it would also emphasise the geochemical nature of potential host rocks (especially C and Fe) rather than their sedimentary origin.CITATION:Phillips, G N, 2013. Origin of Witwatersrand Gold - a viable source region and source process for gold, in Proceedings World Gold 2013 , pp 175-180 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

COLUMBIA SECTION S. S. FOWLER, Chairman., J. C. HAAS, Vice-chairman, LYNDON K. ARMSTRONG, Secretary-Treasurer, 720 Peyton Bldg., Spokane, Wash. W. H. LINNEY. J. F. MCCARTHY. On July 15, 16, and 17, 1918, through the good offices of Secretary Stoughton, and the courtesy of War Department officials, Columbia Section was able to secure a series of moving pictures which were presented under the auspices of the Spokane Engineering and Technical Association.. The title was "The Way Out," representing the activities of individuals who had lost an arm, a leg, or both, yet whose apparent misfortunes were made the stepping stones to advancement in various human activities. The exhibitions were given at Natatorium Park in the evening, each of the three performances being attended by 1000 per-sons. Later the films were shipped to Kellogg, Idaho, where they were shown in the principal playhouse one evening to a full house. On July 31, 1918, the Columbia Section participated in the luncheon and other entertainment in honor of Alfred D. Flinn, Secretary of the Engineering Council, who made a trip through the country to meet different classes of engineers, members of the National Societies, for whom he had a message. The entertainment was under the auspices of the Spokane Engineering and Technical Association, Mr. Peter Mogensen presiding. The luncheon was held in the Elizabethan Room, Davenport Hotel, at noon, 35 engineers being present, of whom about one-third were our members.

Jan 9, 1918

COLUMBIA LOCAL SECTION Executive Committee F. A. THOMSON, Chairman GEORGE W. RODDEWIG, Vice-Chairman L. K. ARMSTRONG, Secretary- Treasurer, P. O. Drawer 2154, Spokane, Wash. R. S. MCCAFFERY S. H. RICHARDSON The quarterly meeting of the Columbia Local Section of the Institute Was held in Pullman, Wash., May 16-17, 1914, as a joint meeting with the Spokane Sections of the. American Institute of Electrical Engineers and the American Society of Civil Engineers, each holding separate sessions on the afternoon of the 16th With a joint meeting in the evening. The Section meeting was held in Science Hall, the Chairman, Prof. Francis A. Thomson, presiding. E. Jacobs, Secretary of the Western Branch of the Canadian Mining Institute, acted as Joint Secretary: About 35 members and guests Were present. H. C. Bellinger, formerly Metallurgical Manager of the Great Cobar Co., Ltd., N. S. W., Australia, described the Horwood process. Papers as follows were presented and discussed: A Smelting Furnace for Cyanide Precipitate, by P. S. Anderson. Mining Methods in Rossland, by C. H. Loux. Geological Notes on a Part of Central Idaho, by Prof. D. C. Livingston. Some Notes on the Ore Deposits of Republic, Wash., by A. M. Balfour. E. Steidl, of the U. S. Bureau of Mines Rescue Car, spoke on the mine rescue service of the Bureau, and E. Jacobs described what is being done along similar lines in British Columbia and elsewhere. The evening was occupied in joint session, J. B. Fisken presiding. Mr. Fisken read a short paper on the benefit to the young engineer of an association y membership in the local section of either of the societies represented in the meeting, and C. F. Uhden gave a stereopticon lecture on Power Development Along the Spokane River.

Jan 7, 1914

By Ben Burger

This paper describes the design, the first three years of operation and optimization of a large, single stage SAG mill at Minera Yanacocha?s Gold Mill facility located in northern Peru. The Gold Mill was commissioned in March 2008 with a 32? x 32? EGL, 16.5MW single stage SAG mill, to process 5 million tonnes per annum high grade oxide Au/Ag ore. Operational control, feed size distribution, grinding media, mill liner, grate and pulp lifter optimisation have allowed the mill to operate 15-30% above design throughput rates, but with a product P80 coarser than design. As part of the optimization, full grinding circuit surveys were conducted. Historical operating data and survey data were analyzed and used to evaluate possible circuit changes and determine alternative operating strategies. A number of changes were implemented which allowed the SAG mill to operate similarly to a large ball mill and achieve finer mill product that was closer to design. This paper summarizes life to date data analysis and improvements made by Minera Yanacocha as well as the grinding circuit optimisation study conducted by Metso Process Technology and Innovation.

Jan 1, 2012