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By W. R. McClelland

GOLD-BEARING ores, representing many types, are found widely distributed through the Province of British Columbia. They range from those which by their nature may be considered as complex, to those whose mineral characteristics are simple. Those in which the gold is associated with metallic sulphides provide particular milling and metallurgical problems, the solution of which involves not only detailed laboratory investigation but also a careful consideration of economic factors. The location of an ore-body may have a deciding influence on the adoption of a method for the metallurgical treatment. Whether the ore should be treated with the object of recovering the gold as bullion or as a shipping concentrate is often dependent on such topographical considerations as the position of the mine at or near tidewater or within a reasonable overland distance of a smelter. British Columbia is fortunate in having the Trail smelter situated in the southern part of the Province, and the smelter at Tacoma, Washington, is accessible for coastwise traffic. Both of these provide a ready market for most types of gold-bearing concentrate. In order that the results obtained by laboratory tests may give a fair indication of what should follow in mill operation, it is essential that the test sample should represent as closely as possible in mineralogical character and in grade the ore that eventually will constitute the feed to the mill. In the early stages of mine development this consideration is sometimes overlooked and samples of a much higher grade than would be representative of run-of-mine ore are submitted. Flotation tests on such a sample of ore high in sulphides may show a low ratio of concentration, bu.t if the actual run-of-mine ore is lower in sulphides the mill operation will reveal a much higher ratio. The recommendations for treatment based on the results of laboratory tests may have been against concentration, when in actual operation this would be the most suitable method of treatment. Recommendations based on laboratory tests are necessarily from the results of work carried out on the sample submitted, modified only by such other economic or topographical information as may be known to the investigator. This paper deals with a few of the gold ores found in the six mining districts of British Columbia and is based on investigations made in the Ore Dressing and Metallurgical Laboratories of the Mines Branch, Department of Mines, Ottawa.

Jan 1, 1937

By Shahé Shnorhokian

A study was conducted on the seismic activities and associated rockburst events that took place at an underground Canadian metal mine over a period of five years. In the first stage, a back analysis of the microseismic database led to the identification of clusters of major events. The locations of these clusters were identified with respect to the local geology and the planned mining sequence. In the second stage, a numerical model was constructed using the finite difference code FLAC3D to simulate the in-situ stress, mine geometry, local geology, and stope sequence. Mining-induced stress fields were compared against two rockburst events that took place during this period, as well as against the various geologic units present. It was shown that by combining microseismic analysis and numerical modeling, it was possible to provide a basis for evaluating the influence of the in-situ stress regimes and stope sequencing on mining-induced seismic response.

May 1, 2011

By M. Mirnezami, D. Lascelles, J. A. Finch, E. El-Ammouri

"In a previous publication, the depressant action of Mg above pH 10 on Cu-activated sphalerite was described (Lascelles et al., 2001). In the present communication, a second role, aggregation is introduced.Aggregation (i.e., the tendency of particles to cluster) is measured using settling rate and turbidity converted to an aggregation index (AI) where 0 corresponds to dispersed and 1 to aggregated. Surveys of Cu and Zn flotation stages at four concentrators showed the A1 increased significantly above pH 9. The metal ions identified in the process waters, principally Ca and Mg, were tested to determine which might be responsible. The presence of Mg was found to be the most important, 50 ppm Mg having a greater impact than 500 ppm Ca fkom pH 9 to 1 1. In one plant, poor repeatability in A1 was suspected to be related to varying Mg levels; doping with Mg significantly increased AI.In both aggregation and depression, therefore, the common feature is the impact of Mg at pH > 9. Over this pH range Mg forms a range of hydroxy species, including Mg(OH)2 precipitates. Suggested aggregation and depression mechanisms associated with these precipitates are introduced. Possible problems and opportunities arising from the findings are discussed.INTRODUCTIONProcess waters in flotation circuits contain a variety of metal ions that may introduce unwanted activation or depression. Two common metal ions are calcium and magnesium. Typical concentrations are in the range 50 ppm Mg and 500 ppm Ca (Marticorena et al., 1994, Basilio et al., 1996, Negeri et al., 1997, Nesset et al., 1998)."

Jan 1, 2002

By T. M. Ruff

A GPS-based traffic awareness and collision avoidance system has been implemented at mines with long, narrow access roads to help avoid accidents involving two approaching vehicles or vehicles following too close. A simple display in the cab of each outfitted vehicle gives an indication of oncoming traffic and a voice announcement indicates the type of vehicle that is coming as far out as 300 meters. Advanced warning of approaching vehicles is increasing driver awareness, especially around blind corners and in adverse weather such as heavy fog, snow, or rain. Speeding alarms have also been implemented and are especially critical as a vehicle approaches reduced speed areas near single-lane bridges or tight curves. A description of the system, safety improvements seen since its introduction, and implementation challenges will be discussed.

Aug 1, 2013

By A. Mazhary

"Although ore sorting in mining is not a new concept, sensor-based sorting has failed to gain broad acceptance due to perceived challenges with the technology. In order to gain wider applications, this research focuses on treating waste rock and low-grade ore to identify and test appropriate sensors and to evaluate the response. Results showed that amenability of rocks to sensor-based ore sorting is both sensor and ore specific. It was also observed that the efficiency (recovery) of sorting is directly influenced by the degree of heterogeneity of the rocks. The overall outcome showed that with the right sensor, several of the materials tested are amenable to sensor-based ore sorting. Mining companies could benefit from multiple economic and design impacts, such as lower energy cost, lower transportation costs, higher metal recoveries and smaller footprints that lead to more sustainable mining. This paper will focus on the effects of heterogeneity of rocks on sorting potential and efficiency.IntroductionSensor-based ore sorting has been attracting more attention since the pressure for effective resource extraction and management has increased. An urge to make most of the current deposits, and to make the low-grade deposits economic to mine has ushered the technology to find new ways to overcome the new challenges. No matter the terminology used, such as coarse beneificiation, waste rejection, particle or bulk sorting, the purpose of sensor-based ore sorting is to remove low-grade rocks before the comminution circuit, increasing the feed head grade and quality while reducing the energy costs related to comminution.Despite nominal advantages, there have always been some concerns that have impeded the intorduction and acceptance of the technology. One of the most important shortcomings of ore sorting is their capability, or capacity, to keep up with the high-tonnage mining. Some other issues that have been mentioned as drawbacks to sorting include installation cost of such devices, feed preparation for effiecient sorting along with accuracy of sorting and probability of false negatives (Manouchehri, 2003)."

Jan 1, 2015

By J. R. Emery, D. F. Coates

"FOUR PAPERS ON CEMENTED BACKFILL were given at the Annual General Meeting of The Canadian Institute of Mining and Metallurgy in 1970:Weaver, W. S., and Luka, R., ""Laboratory Studies of Cement-Stabilized Mine Tailings"".Pasieka, A. R., Beattie, H. F., and Espley, G. H., ""Cemented Hydraulic Backill within the Falconbridge Group of Companies"".McLeod, P. C., and Schwartz, A., ""Consolidated Fill at Noranda Mines Limited (Geco Division)"".Clement, W. P., and Sokoloski, R., ""Pumping Cemented Backfill"".These four papers give the impression of a development in mining technology that has been substantially completed. Somewhat over ten years ago, The Inter-national Nickel Company of Canada, Limited and Falconbridge Nickel Mines Limited started experimenting with the addition of Portland cement to mill tailings to produce improved backfill and cheaper floors for scraping. Shortly after, the Canada Cement Company Limited (now Canada Cement Lafarge Ltd.), with full support of the two mining companies, started an extensive research program to provide the technologic-al data necessary to exploit what was obviously going to be a significant development in mining technology."

Jan 1, 1970

By Paul Miranda, Corby Anderson

"The Center for Advanced Mineral and Metallurgical Processing (CAMP) has recently obtained a Mineral Liberation Analyzer (MLA). CAMP has utilized the technology for several projects with excellent results. The MLA is able to both analyze size and quantify mineral phases. Therefore, the MLA is becoming the Sherlock Holmes of the mining and metallurgical industry. For this presentation, four projects have been evaluated and data was collected using the MLA. The first project involved tungsten mine. Previous mining practices have yielded poor tungsten results and recoveries. By using the MLA, tungsten mineral phases, along with possible contaminants, were verified and the results used to try to increase overall tungsten recoveries. The second project evaluated a molybdenite/chalcopyrite concentrate with surprising results. The third project is a silver project. Initial flotation scoping tests were performed by attempting to separate silver from gangue material. Because of the poor recovery results (less than 5%), MLA was used to determine possible scenarios for increasing silver recovery. Finally, the last project involves gold evaluation in tailings. For all projects, MLA application results will be presentedand discussed.INTRODUCTIONThe Center for Advanced Mineral and Metallurgical Processing (CAMP) has recently received a software add-on to a scanning electron microscope (SEM) located at Montana Tech. The Mineral Liberation Analyzer (MLA) technology was developed by Dr. Ying Gu of the JKTech Center of the University of Queensland. Since August 2006, CAMP has received and processed over 50 samples. These samples include a total mineralogy of tungsten ore samples, gold tailings, lead zinc tailings pile, molybdenite concentrates, copper concentrates, as well as others. During analysis of these received samples, the technology allows the samples to be quantified mineralogically with some surprising results.For analysis, the samples were initially sieved between 170 to 200 screen sized mesh. This ensures that received samples mineral size is fairly uniform. The samples are then placed into epoxy and allowed to harden. Next, the samples are polished and carbon coated for MLA analysis."

Jan 1, 2007

By Rodolfo Espinosa

"Industrias Peñoles, S.A. de C.V. in Mexico, has nine mining operations, six managed by Peñoles (base metal mines) and three managed by Fresnillo plc (precious metal mines). Seven of the operations use flotation and the other two are heap leach operations, one for gold and the other one for copper.This paper gives a brief introduction of Peñoles, shows mine locations and describes the main process characteristics of each concentrator. It also presents four of the new operating practices that were implemented over the last four years to improve the economics of the mining operations. These include (1) the use of centrifugal gravity concentrators to increase the recovery of gravity recoverable gold (GRG) and silver (GRS), (2) the use of expert systems to reduce process variability while increasing grades and recoveries, (3) the application of the Six Sigma methodology to key projects to ensure success and personnel development and (4) the use of water chemistry fundamentals to identify chemistry problems and design adequate solutions for improving grades and recoveries.INTRODUCTIONPeñoles was founded in 1887. It is a mining group with integrated smelting, refining and chemicals producing operations. Peñoles is the world largest producer of refined silver and metallic bismuth, the leading Latin American producer of refined gold and lead. It is amongst the world leading producers of refined zinc and sodium sulfate.Peñoles operates and controls six underground mines in Mexico and is the largest producer of zinc and lead of the country. It also produces copper concentrates and cathodes. Through its 77.1% equity stake in Fresnillo plc (a London Stock Exchange listed company); Peñoles is also a significant producer of gold and silver. Fresnillo plc operates three precious metal mines in Mexico. While Fresnillo is the world largest primary silver mine, Ciénega and Herradura are two leading gold mines of Mexico. Figure 1 shows a map of Mexico indicating the locations of the Peñoles mines. The main process characteristics of each concentrator are listed in Table 1."

Jan 1, 2011

By Cosmin Carpinisan, Erich J. Hofmann, Stephen J. Hall

"Since presenting a technical paper regarding their unique capabilities in Forged Steel Mill Gearing at the SAG-2006 Conference, Australian heavy engineering company Hofmann Engineering has pioneered a number of new manufacturing processes and design concepts for components of large comminution equipment. These include: 1. Novel design improvements for HPGR Rolls with forged steel tyres and a unique patented tungsten carbide insert designed to improve wear life, enhance autogenous layer build-up, and to reduce breakage & chipping under load. 2. Development of forged fabricated Mill Heads using rolled & welded high-tensile steel plate as alternatives to cast conical mill heads. 3. Insitu Girth Gear measurements for profile and wear via portable 6-axis CMM. 4. Gear and Pinion designs to AGMA-6114 for SAG mills of 38’-40’ diameter to 24MW and for Ball Mills of 26’ diameter to 18MW. The paper presents case studies from the Australian heavy manufacturing facilities of Hofmann Engineering, combined with news of their new gear manufacturing and gearbox overhaul facility in Canada."

Jan 1, 2012

By R. L. Amelunxen

"In January 1983, Gibraltar Mines Ltd. started an exploratory program on Column Flotation with hopes of improving performance of the Molybdenum Cleaning circuit. The encouraging results led to a column test trial in the Bulk Copper Cleaner circuit where the test unit has per¬formed well. A program was undertaken to understand the mechanics of column operation. A year and a half later, Gibraltar is considering the replacement of existing Bulk Copper and Moly Cleaning flotation cells with a fully computer con¬trolled Column Flotation circuit.BRIEF SUMMARY OF TESTWORKInitial testwork was done with a home made 20 inch diameter x 31 foot high column, equipped with a doppler flow-meter at the tail line and automatic level conrol. This loop maintained constant level in the column by throttling the tail valve. This column was placed in a variety of locations around the Moly circuit as shown on Figure 1 a, b. Test re¬sults indicated that the column could achieve much higher grades than the conventional cells, but recovery wise, the performance was low. Spillages from overloaded pump boxes were a common frustration during this time.Column control strategy was reviewed; and, in light of information received from McGill University, changed to conform with the methods that had been employed by D. Wheeler, of the Column Co. of Canada4 and Gaspe Copper Mines3.The column was tested replacing a portion of the bank, figure lc. The results obtained were more or less equal to the circuit. However, as we had Nitrogen gas connected to the column and not the regular cells, the column was kept in service. With the use of Nitrogen in the column, the usual copper depressant, Sodium Cyanide could be replaced with Sodium Hydrosulphide, hence lower operating cost.As time went on, a 10 inch diameter column was added in series to re-treat the concentrate of the 20 inch diameter column with hopes that the copper content would decrease from 0.6% down to 0.3% in order to save on subsequent leach¬ing costs. So far, results indicate there has been some im-provement, hut we are not achieving 0.3% copper. (See figure 1d)."

Jan 1, 1985

By John Plecash

This paper comprises a general outline of all of the developments, including the history, geology, mining, milling, power and transportation installations, at the gold mining operation of La Luz Mines Limited and the copper mining operation of its wholly-owned subsidiary, Rosita Mines Limited, both located in north-central Nicaragua. The low-grade, gold-bearing ore-bodies of La Luz Mines, contained in highly fractured and folded Lower Cretaceous sedimentary rocks, were from 1909 to 1928, mined and treated by primitive methods by the La Luz and Los Angeles Mining Company. The abandoned property was acquired by La Luz Mines Limited in 1936, and was equipped with modern machinery and put into production in 1939. Between 1939 and 1948, the daily rate of production was in-creased from 300 tons per day to 2,-000 ton per day. The ore reserves available for open-pit mining were depleted in 1954. Since then, the entire production has come from under-ground operations.

Jan 1, 1963

By T. Chong, R. Pesalj, B. Marchant, Z. Nikic

"The Mount Polley copper/gold project is located in central British Columbia and is currently being developed by Imperial Metals Corporation. Extensive laboratory and pilot plant testing was required to develop acceptable metallurgy for recovery of both sulphide and oxide copper-gold mineralization. Copper recovery is highly sensitive to oxide copper content of the feed whereas gold is primarily associated with the copper sulphide minerals. A conventional flowsheet where sulphide flotation is followed by sulphidization and oxide scavenging is described. The conventional flowsheet was used in a feasibility study which resulted in a favourable production decision at Mount Polley. Detailed engineering and permitting are in progress.More recently, laboratory and pilot testing of a new flotation reagent, S-6493*, an oxide specific collector, has indicated that improved copper recovery can be accomplished with reduced reagent consumption, including elimination of the sulphidization step, using S-6493 compared with the conventional flowsheet. The comparative metallurgical results using S-6493 and conventional sulphidization methods are presented, from both bench scale and pilot testing. Comparative economics of the conventional flowsheet and that using S-6493 are also presented. Advantages of S-6493 include reduced reagent costs, increased revenues from additional copper recovery, and overall reduction in capital and plant operating costs due to the simplified flowsheet. INTRODUCDONThe Mount Polley copper/gold property is located in Central British Columbia, 56 air kilometres northeast of Williams Lake. The first recorded exploration was in 1964. By 1989, a total of 238 diamond drill holes, totalling 27, 522 meters, was completed to detail reserves on the Mount Polley prospect. A number of drill core composites were submitted, containing a variety of oxide copper levels, for metallurgical flowsheet development. Six bulk samples were collected from surface trenches for additional bench scale testing and for pilot plant testing."

Jan 1, 1991

By E. S. Moore

"The Centre of the silver-producing section of the Gowganda area lies about 55 miles northwest of Cobalt, and the village of Gowganda is 71 miles by road from New Liskeard. The geological similarities of the Gowganda and Cobalt areas led prospectors westward from the rich Cobalt field, first to Elk Lake and then on to Gowganda, where mineralization was found in 1907. A year later many showings were found, and rich hand-picked ore was shipped. Most of the ore has come, however, from two mines, both of which are still operating; the Miller Lake-O'Brien, which was purchased by Siscoe Metals of Ontario Ltd. in 1945, and the Castle-Trethewey. The annual production of these two mines runs over one and one-half million ounces of silver and considerable cobalt. The total production of the camp has reached about 32,000,000 ounces of silver and a large amount of cobalt, the total not recorded.General GeologyThe general geology of Gowganda is in many respects much like that of Cobalt. There are areas of Keewatin basic and acid Javas mixed with tuffs and basic intrusions. These rocks are deformed and partly altered to schists, and have been intruded by some Haileyburian basic and ultra-basic rocks and by Algoman granite. These were followed by a large number of porphyritic Matachewan quartz diabase dykes. After a period of extensive erosion the Huronian sediments were deposited on a pene-planed surface over all the older rocks; these sediments include large quantities of conglomerate (partly tillite), quartzite, and greywacke. The Keweenawan rocks include the Nipissing quartz diabase sill, later quartz diabase dykes, and one long olivine diabase dyke, the latest Precambrian rock. The area has been extensively glaciated.Structural FeaturesThere has been little folding in the area since the Algoman batholiths were intruded, and the Huronian sediments lie nearly flat, with dips of 10, 15, or rarely 25 degrees. The Matachewan dykes show a remarkably uniform, nearly north strike, indicative of east-west tension when they were intruded. On the other hand, the dykes later than the sill strike nearly east, tangentially to the northeasterly and northwesterly strikes of the Miller Lake basin."

Jan 1, 1949

The information in this document has been prepared as at February 16, 2011. Certain statements contained in this document constitute ?forward-looking statements? within the meaning of the United States Private Securities Litigation Reform Act of 1995 and forward looking information under the provisions of Canadian provincial securities laws. When used in this document, the words ?anticipate?, ?expect?, ?estimate?, ?forecast?, ?will?, ?planned?, and similar expressions are intended to identify forward-looking statements or information. Such statements include without limitation: statements regarding timing and amounts of capital expenditures and other assumptions; estimates of future reserves, resources, mineral production, optimization efforts and sales; estimates of mine life; estimates of future internal rates of return, mining costs, cash costs, minesite costs and other expenses; estimates of future capital expenditures and other cash needs, and expectations as to the funding thereof; statements and information as to the projected development of certain ore deposits, including estimates of exploration, development and production and other capital costs, and estimates of the timing of such exploration, development and production or decisions with respect to such exploration, development and production; estimates of reserves and resources, and statements and information regarding anticipated future exploration; the anticipated timing of events with respect to the Company's minesites and statements and information regarding the sufficiency of the Company's cash resources. Such statements and information reflect the Company's views as at the date of this document and are subject to certain risks, uncertainties and assumptions, and undue reliance should not be placed on such statements and information. Many factors, known and unknown could cause the actual results to be materially different from those expressed or implied by such forward looking statements and information. Such risks include, but are not limited to: the volatility of prices of gold and other metals; uncertainty of mineral reserves, mineral resources, mineral grades and mineral recovery estimates; uncertainty of future production, capital expenditures, and other costs; currency fluctuations; financing of additional capital requirements; cost of exploration and development programs; mining risks; community protests; risks associated with foreign operations; governmental and environmental regulation; the volatility of the Company's stock price; and risks associated with the Company's byproduct metal derivative strategies. For a more detailed discussion of such risks and other factors that may affect the Company?s ability to achieve the expectations set forth in the forwardlooking statements contained in this document, see the Company's Annual Report on Form 20-F for the year ended December 31, 2009, as well as the Company's other filings with the Canadian Securities Administrators and the U.S. Securities and Exchange Commission. The Company does not intend, and does not assume any obligation, to update these forward-looking statements and information. Marc Legault, a Qualified Person and the Company?s Vice-President, Project Development, reviewed the technical information disclosed herein. For a detailed breakdown of the Company?s reserve and resource position see the February 16, 2011 press release on the Company?s website. That press release also lists the Qualified Persons for each project.

May 1, 2011

By J. R. Goode

ABSTRACT Aurora Energy Ltd. is considering a 10,000 t/d process plant to produce 97 million lb (43,998,460 kg) of U3O8 over a 17-year project from uranium deposits in coastal Labrador. This paper summarizes the test work, mostly done by SGS Mineral Services in Lakefield, Ontario, and the economic studies supporting flowsheet selection. The proposed flowsheet includes semi-autogenous grinding (SAG) and ball milling, acid leaching using air/SO2 as an oxidant, and resin-in-pulp (RIP) extraction of uranium from the leached slurry. Other unit operations examined include ore sorting, heap leaching, liquid- solid separation, solvent extraction, and nanofiltration for eluate upgrading. We also review the extensive environmental test work and studies that were completed.

Jan 1, 2012

By Cecilia Arrue, Dominic Fragomeni, N. O. Lotter

"A statistically designed benchmark mill survey was carried out in July 2005 at the Kidd Creek Concentrator, D Division circuit, which processes Ni/Cu ore from the Montcalm deposit. A structured statistical survey approach was followed, together with defined quality controls, which would assign a 95 percent level of confidence in the result.A set of six surveys were completed over a limited time; the corresponding stream samples of the surveys found acceptable were combined to obtain high confidence composite samples. The head grade of each survey is compared to two distributions to test its acceptability; surveys that fail to conform to these trials are rejected. The accepted set of surveys, which is a robust representation of the process, is prepared into a composite for QEM-SEM analysis and mass balance purposes.Where the above practice is a standard procedure in Falconbridge for QEM*SEM purposes, in this case each individual two-hour survey unit was measured and analysed for a mass and value balance. It is shown that none of the individual mass and value balances close as well as the composite set of accepted two-hour survey units. This founding is in keeping with the averaging properties of the Central Limit Theorem.INTRODUCTIONMontcalm OperationsNi/Cu bearing ore from the Montcalm deposit is being processed at the Falconbridge, Kidd Creek Concentrator in a modified D Division circuit. The circuit was commissioned in the fall of 2004. Ore is crushed at the minesite to –19 mm and trucked to Kidd for delivey into the 4 parallel fine ore bins.Ore is milled in a rod mill followed by cyclones and 2 parallel ball mills. The grinding circuit treats Montcalm ore at an average feed rate of 100 wet tonnes/hour (750,000 tonnes/annum) and produces a flotation feed particle size of 83% -53 um. A simple flowsheet including bulk Cu/Ni roughing and 2 bulk cleaning stages followed by Cu/Ni separation in 2 stages is practiced. Soda ash is used as a pH modifier in bulk flotation. SIBX is the collector. Lime and Dextrin are added into Cu/Ni separation for the depression of pentlandite."

Jan 1, 2007

By R. S. Bowman, G. S. Austin, J. M. Barker, P. S. Freeman

The physical, chemical and mineralogic characteristics of zeolites allow commercially important applications. While adoption of zeolite technology is slow in the United States compared to other regions of the world, continued testing and research has shown a wide range of uses for these minerals. They are important catalysts in petroleum refining, molecular sieves able to separate gases, and chemically inert carriers of reactants. The zeolite clinoptilolite produced by St. Cloud Mining Company (clino) (SC) is used in animal hygiene and animal feed, especially concentrated animal feeding operations (CAFOs), horticulture, water treatment, floor dry, aquariums, air and other filters, and odour control. Clino can remove cations from solution, and surface-modified zeolite (SMZ) is a sorbent for the removal of anions and neutral organics from water. Specific clino applications are: control of chemical pollution in groundwater, removal of organic compounds from oil field waters, and elimination of pathogens from sewage effluent. Combining the sorption capabilities of SMZ with chemical or biological transformations can yield complete removal of toxic materials from contaminated water. Continued development and marketing of zeolite products will be a growth market far into the future. The CAFO market for zeolites is the most significant growth area in the United States over the next few years. SMZ, currently less than 1% of St. Cloud sales, will continue to gain market penetration for many years.

Jan 1, 2004

By The Staff

FOR forty years cyanide men have been intensively engaged on the treatment of sulpho-telluride ores. So far as we know, the processes used today were-with the important exception of the concentration plus high-lime process at the Victor mill (1915)-in use, or had been tried, in the earl y years of the century. Roasting, bromocyanide, ordinary cyanide, table and vanner concentration, floating and treating the concentrate, roasting con-centrates prior to treatment, etc., all were used at Kalgoorlie in 1904 or earlier. Flotation, followed by shipment of the concentrate to the Golden Cycle mill, was the practice at the Vindicator mine, Cripple Creek, for some years prior to 1917. Similar practice was employed in the Portland Independence mill at Victor, Colorado, and was lacer superseded by the table concentration, high-lime cyanide treatment of rails of the older Portland Victor mill. During all this time, an immense amount of research was being clone on these ores by the staffs of numberless companies. Conclusions were drawn and mills built. But if the results of one per cent of this research were ever published in sufficient detail for intelligent use by others, the Lake Shore staff has been unable to discover them, or does not recall having clone so. Government laboratories-as for instance chose of the Mines Branch, Ottawa, in or about 1927-have touched upon certain methods in their publications, but they simply have not had the time to finish the job. The paper by W. E. Johnston, Tellurides-Problem or Alibi? (E. & M.]., Aug., 1933), aroused wide interest and comment. It published conclusions, some right and some wrong, and gave the evidence adduced by the author i:n support thereof. Conclusions published without supporting evidence are to most of us worse than no conclusions at all. We suggest chat, if even one-tenth of the operators had published full, detailed results of their laboratory work, ad vance in the treatment of sulpho-telluride ores would have been very much accelerated. Therefore, we venture to inflict upon the Institute a compendium of the results of laboratory work performed during the past few years at the Lake Shore mill. It is really a summary of the more interesting results to date, prepared by the mill staff for their own use and benefit. But we hope chat the discussion under any heading is so detailed chat it will be intelligible to anyone interested in that phase of the subject.

Jan 1, 1936

By R. Blosser

Phelps Dodge introduced a process improvement model known as Quest for Zero in 2001. In 2004, the focus of Quest for Zero shifted from corporate-led initiatives to projects led by site personnel. The Hydrometallurgical Division at Morenci focused on two (2) significant process improvements: reducing electrolyte bleed and organic losses. In September 2004, Morenci kicked off a bleed reduction project to reduce electrolyte bleed by 45%. By the end 2005, electrolyte bleed was reduced by 55% through understanding and reduction of variance. Significant process changes made during this time period include changes in acid-addition strategy, reduction of uncontrolled bleed, and optimization of bleed placement. In April 2005, the organic reduction project began with the goal of reducing losses by 15%. Operational improvements during this project included improved organic recovery systems, mixer speed optimization, and picket fence installation. By the end 2005, this project reduced organic losses by 35% and current losses are 48% lower than at the start of the project. These projects and smaller Questfor Zero projects have resulted in sustainable annualized savings of $13 million in Morenci hydrometallurgical operations. Through the use of Six Sigma tools, process variances can be controlled and reduced.

Jan 1, 2007

By Milton Fies

Introduction The first experiment in underground gasification of coal in the United States was conducted at Gorgas, Walker county, Alabama, under a co-operative arrangement between the U.S. Bureau of Mines and the Alabama Power Company, at the suggestion of the Power Company. The test was conducted on property of the Alabama Power Company, that owns some 19,000 acres of coal-bearing lands on which there is developed a highly mechanized mine producing some 2,500 cons of good quality steam coal per day. At the same locality ?there is a 200,000 kilowatt steam plant one of the largest in the southern portion of the United States. The Alabama Power Company owes much of its beginning in 1912 to British vision and courage. The original plans for building hydroelectric plants in Alabama, and for the construction of necessary transmission lines, were submitted to Sperling & Company, bankers of London, who agreed to underwrite certain bond issues, the proceeds of which would be used in launching the new Company on its programme. The set-up by which these funds from England were received was through an intermediary Canadian company, which the English investors desired. The Canadian company - Alabama Traction, Light and Power Company, Ltd. became owner of the securities of the Alabama Power Company and marketed its own securities through the banking house of Sperling & Company. Without assistance at this time the Alabama Power Company could not have gone ahead with its programme of expansion and the bringing together of the properties necessary for laying the foundation for a strong Company, fortified with ample power resources essential for future requirements and for dependable service to the public.

Jan 1, 1948