Search Documents

By Jr. Jones

This paper is derived from a document that compiles autogenous and semi-autogenous mill installations worldwide, through the end of 2010. Updates have been solicited from all major mill manufacturers and most have responded. A review of AG/SAG mills sold to date and in the last five years indicates that the AG/SAG mill market is very healthy and the trend is larger diameter mills with high diameter-to-length ratios. Ring motors (gearless) are the preferred drives for large mills even though the power transmitted through a gear drive is expected to near 11,000 kW per pinion in the near future.

Jan 1, 2012

By J. A. Finch

Solvent-coated air bubbles in the Air-Assisted Solvent Extraction (AASX) process achieve the dual role of high solvent specific surface area and ease of phase separation. The thickness of the solvent film is of fundamental interest but difficult to measure directly in the process itself. As an approach interferometry (in the UV-vis region) was used to measure the time dependent thickness of a film formed by blowing an air bubble in kerosene-based solvents. The film was stabilized by the presence of 1.5 ppm silicone oil, as employed in AASX. The film appears to comprise two layers; an outer "free" layer of almost constant thickness and an inner "bound" layer which decreased in thickness with time. The bound layer is considered relevant to AASX. For a 20 mm diameter bubble blown in LIX/kerosene solvent the initial thickness was ~ 3 um which decreased over 10 minutes to a final rupture thickness of 500 nm. The bound layer thickness and time to rupture decreased with decreasing bubble size. Correspondence to prior indirect estimates of solvent layer thickness is examined.

Jan 1, 2006

By C. J. Cajka

Commodity agreements, trade liberalization, producer cartels, the New International Economic Order, price stabilization and access to supply are buzz words of the day. The international concern and dialogue on these concepts, often by a new breed of politically motivated experts, have generated intense interest in seeking an international solution to natural resource problems. While this momentum was maintained during the past year, the growing incidence of protectionist actions by several major nations has been eroding confidence in the global approach. The seriousness of current difficulties has created an urgent need for decisive action. At the same time, the limitations of the global approach have become more evident.

Jan 1, 1978

By C. M. Diaz, P. J. Mackey

Since its inception, in 1987, the Copper-Cobre series of conferences has established itself as the prime world forum for discussing advances in copper process metallurgy, in particular copper sulfide smelting, copper recovery by leaching and electrowinning and copper electrorefining. All copper producing countries have actively participated in the pyrometallurgy symposia held in the framework of these conferences. In 1999 and 2003, the close to 100 pyrometallurgy papers that were presented had to be accommodated in two volumes. In the present paper, the authors firstly provide a brief historical sketch of the Copper-Cobre conferences and then focus on providing a retrospective look at the dramatic changes that have taken place in copper smelting in the last few decades, primarily as discussed in the Copper-Cobre and precursor conferences pyrometallurgy proceedings. Topics include: the development of autogenous, increasingly more intensive, environmentally sound and energy efficient smelting processes; significant improvements in Peirce-Smith converting practice and at the same time the commercialization of alternative continuous converting routes; the consequent expansion and modernization of smelters; the increasing compliance with strict government environmental regulations in most copper producing regions of the world; the realignment of the copper smelting industry throughout the world; and trends in copper smelting R&D. A look at the future closes these reflections on the contribution of the Copper-Cobre conferences to the advancement of copper smelting technology.

Jan 1, 2007

By V. N. Mackiw, H. Veltman

"A process is described which permits the separate recovery of lead and zinc from complex low-grade sulphide concentrates such as are produced from the New Brunswick type of disseminated pyrite ores. This process calls for the preparation of a lead-zinc bulk concentrate from the original ore by flotation. The bulk concentrate is then oxidized under pressure in autoclaves in aqueous sulphuric acid solution, such as return electrolyte from zinc electrolysis. This yields a zinc sulphate solution and a residue containing lead sulphate, unaltered pyrite and elemental sulphur generated during the oxidation. After the oxidation, the leach slurry is briefly heated to above the melting point of elemental sulphur and then cooled. Thus, pellets containing pyrite and elemental sulphur are formed, and they are separated from the lead sulphate by screening and/or flotation. Laboratory tests have shown that about 95 per cent of the zinc and lead can be separately recovered from complex bulk concentrates. Process possibilities are discussed."

Jan 1, 1967

By T. Patching

"Introduction The occurrence of coal was first reported in the Drumheller area in 1793 but it was not until 1912 that production of coal was recorded. In that year 13,000 tonnes were mined in the Drumheller area. Three years later the Drumheller mines ranked next in the Province to those in the Crowsnest and Lethbridge districts, with an output of 225,000 tonnes. By 1917 production had increased to 600,000 tonnes, moving Drumheller to second place in output in the province, second only to the Crowsnest district. It held this rank until 1960. Production, almost all from underground mining, rose to over a million tonnes a year by 1920 and remained between one and two million tonnes per year until 1954. Competition from newly discovered oil and natural gas, beginning around 1950 caused a steady loss of domestic coal markets, especially from underground mines. By 1960 Drumheller's production had fallen below a half a million tonnes per year and the field ranked third in output in the province, being surpassed by new stripping operations in the Castor field. By 1965 only a couple of producing mines remained in the Drumheller valley, and output was only about a quarter of a million tonnes per year(1). Throughout the life of the field production was seasonal, depending mainly on the domestic heating market. In 1979 the last mine ceased production. For the last several years of its operation it had remained open in the summers to provide tours for visitors(2). The Drumheller mining operations were located along or near the Red Deer River valley which is 300 to 400 feet deep, and extended from a few miles above the city of Drumheller to East Coulee, about 13 miles down the river in a south-easterly direction. Intervening mining communities existed for some years at Wayne and Rosedale. During the peak years of production some 2000 to 2500 miners and their families lived in these communities and the surrounding areas."

Jan 1, 1985

By P. O. Parfitt

At the McIntyre mine, there are two distinct operations: a gold mine with narrow veins, mined by cut-and-fill methods, and a copper mine with large, open, long-hole stopes. The application of the Critical Path Method to scheduling work in the copper mine, where it has been used successfully for several years, is de-scribed briefly. This application is relatively simple. Use of C.P.M. has now been extended to the gold mine. To replace the former method of scheduling from bar-charts, a procedure was developed for scheduling automatically. To handle an operation of this size and complexity, a computer was essential. Improved schedules are now being produced, with a saving in time.

Jan 1, 1967

By Josée Dartois

En 1988, à l?instar de plusieurs états du monde industrialisé, le Québec décidait d?accélérer la cadence de l?assainissement des rejets industriels et lançait un programme intégré de réduction de la pollution industrielle visant, à la fois, les rejets dans le milieu aquatique, les émissions atmosphériques et les matières résiduelles. Ce programme fut intitulé le Programme de réduction des rejets industriels.

Nov 1, 2002

By Mitchell P. Rothman

This paper concentrates on profits and other measures of return in the Canadian mining industry, especially in the non-mineral-fuels sector. The paper examines the historical patterns of mining profits, both before and after taxes, as compared with profits in other sectors of the Canadian economy, as well as some of the more important influences on mining profits. These include the prices of mineral products, provincial and federal tax policies with respect to mining , and the effect of inflation on mining profits and the financial position of mining firms - in each case, comparing mining with the other sectors of the economy. Finally, the paper provides an analysis of current and prospective rates of mining profits in relation to the capital required to ensure the future viability of the Canadian mining industry.

Jan 1, 1977

By R. G. Rosehart, S. Y. Lee

"The current investigation concerns the removal of arsenic from waste waters using ion-exchange resin and activated carbon as sorption media. Use of certain weak and strong base anion exchange resins permits the removal of arsenic. Arsenic may be loaded on the weak base resin in the pH range of 2 to 3 and on the strong base resin above pH 5. The elution of arsenic is successfully achieved using 0.5 M NaCl or a mixture of NaCl and NaOH. The activated carbon investigated was less effective on loading arsenic, but the arsenic loaded was easily eluted by simple pH adjustments."

Jan 1, 1972

By Harry F. Weaver

WHEN 1 was assigned by the Director of the United States Bureau of Mines to present a paper at this annual meeting of the Mining Society of Nova Scotia, 1 was grateful, honoured, and elated to realize finally a life-long desire to see your beautiful land and visit with you who have the good fortune to live and work here. Naturally, in preparing for this important event, 1 wanted to give you something of special interest within the limits of the subject so I chose an area dose to my heart -the operation of our Federal coal mine inspection service, which has, as its fundamental purpose, the prevention of accidents in and around ?Coal mines. In 1957 the United States had 10,879 active coal mines scattered throughout 28 States and the Territory of Alaska. The production of coal for the year was about 515,472,000 tons, including 2.5,472,000 tons of anthracite and 490,000,000 tons of bituminous coal and Hgnite. Anthracite is mined principally in a comparatively small area of one State. AU the 28 States and the Territory produce bituminons coal and/or lignite. The beds mined range from 18 inches to more than 100 feet in thickness and from the horizontal to the perpendicular.

Jan 1, 1958

By D. L. Cramp

The Direct-Connected Electric Hoist In the latter part of 1931 a new electric hoist was installed at the Lake Shore mine. A number of interesting features were incorporated in this machine, which is the first direct-connected, direct-current-operated hoist to be placed in service in the Kirkland Lake district. Many factors requiring care and study enter into the selection of hoisting-engine drive. In this instance, conditions warranted the selection of the generator voltage control system (Ward-Leonard), utilizing a direct-current driving motor and a separate motor generator unit. It was further deter-mined that additional economies could be secured by the selection of a motor generator unit with a flywheel, and consequently the Ilgner-Ward Leonard flywheel set was adopted. Some of the advantages of this system are: 1) Greater accuracy of control, resulting in increased flexibility in hand-ling with increased precision and safety; especially desirable in large, important installations where the rope-speed is high or where frequent shifting is necessary. (2) Reduced energy consumption. (3) Feasibility of load equalization, without which, in some cases, the power system would be unable to carry the fluctuating load imposed on it by the operation of the hoist. ( 4) Elimination of reduction gearing in the construction of the hoist. The hoist is located on the surface and is used for skip operation at the main shaft, hoisting ore from a present maximum depth of 4,200 feet.

Jan 1, 1933

By M. Stogran-Baker, E. Legault-Seguin

"Fluorspar mining in the St. Lawrence area of Newfoundland and Labrador began in the 1930s and ended in the mid-1980s. In 2013, Canada Fluorspar (NL) Inc (CFI) discovered a new ore body, the AGS vein, which proved amenable to more economic open pit mining methods and began developing this resource. This paper discusses the flowsheet development of the AGS vein deposit. Testing at SGS began in 2009 with samples from other deposits in the area. The testwork included pilot-scale dense medium separation (DMS), laboratory-scale flotation tests to develop the flowsheet and a flotation pilot plant. The more recent work that is presented here has been devoted to the AGS vein, and included a variability testing program that gave tremendous insight into the metallurgical drivers of processing the deposit. The ore was found to be fairly variable in terms of fluorite grade, but also gangue mineralogy, which had greater implications on the DMS performance. The gangue mineralogy was also found to significantly impact the grindability characteristics of the DMS product. This paper will detail the testing conducted and the mitigating steps which were identified for the operation.INTRODUCTION Fluorspar is the industrial trade name for the mineral fluorite (CaF2), which is the primary industrial source of fluoride. There are a number of categories of fluorspar, most notably acid-grade fluorspar and metallurgical fluorspar (metspar). Acid-grade fluorspar has stringent specifications and is suitable for the production of hydrofluoric acid that is used for many applications. The typical specifications of acid-grade fluorspar are >97% CaF2 and less than 1% each of SiO2 and CaCO3, with a particle size distribution in the order of 80% passing 100 µm. Metspar is typically used for metallurgical purposes, typically as a flux in smelting, and has significantly more relaxed specifications (< 15% SiO2). The principle source of fluorspar in Canada has been from the Burin Peninsula in Newfoundland and Labrador. More than 3 million tonnes of fluorspar were produced there between 1940 and 1978 and from 1987 to 1990, when production ceased (Fulton & Montgomery, 1994)."

Jan 1, 2018

By Y. Okita

The Goro Nickel Process, developed over a ten-year period, uses a number of novel processing steps and treats two ore types, limonite and saprolite, together. Nickel and cobalt are solubilized using a 270°C pressure acid leach in sulphuric acid, which rejects the bulk of the Fe into the leach residue as hematite particles. The leach liquor, after CCD, is aerated to oxidize any ferrous iron to the ferric form and is neutralized with limestone to precipitate iron as hydroxides together with gypsum from the neutralization of the free acid. Further neutralization with lime, together with steps to remove suspended solids, reduces the iron to trace concentrations. Nickel and cobalt are directly recovered from the low-iron leach solution by primary solvent extraction using Cyanex 301® (SXl) in a high-strength hydrochloric acid solution. Nickel is subsequently separated from cobalt in a secondary solvent extraction circuit using tri-isooctylamine. A granular nickel oxide is made by pyrohydrolysis, and this allows the recycling of hydrochloric acid to SXl. The process is currently being commercialized to produce approximately 60,000 t/y of nickel as nickel oxide granules and approximately 5,400 t/y of cobalt as cobalt carbonate. This paper describes the process development to control the Fe concentration in the SX1 feed solution.

Jan 1, 2006

By J. Suarez Condezo, E. Herrera Alarcon

The Ilo Smelter Modernization Project will require treating the slag from the Peirce Smith converters in Slag Cleaning Furnaces using pig iron technology. Currently the slags from the converters show variable magnetite contents. The copper contained in this slag is recovered in Reverberatory Furnaces, where the smelting rate was improved due to the high silica content of the converter slag. Preliminary industrial tests where developed to clean the slag from converters using pig iron. The results showed that the magnetite content has a significant influence in this process. This work describes the actions that are being implemented in the converter operation to control the magnetite content in the slag in order to maintain the high copper recovery of the smelter when the new facilities are commissioned. This task will demand a strong control of both the slag chemistry and converter practices in order to get the copper recovery considered as the design criteria (~97.4%).

Jan 1, 2007

By G. M. Castillo

Newmont?s Phoenix mine started production in March of 2006. Due to the extreme hardness of the ore, the mill has struggled to meet throughput projections. Grinding studies showed that optimizing the existing circuit would not achieve budgeted throughput. These studies also showed that the pebble crusher was being underutilized due to the inability of the SAG mill to break the rock. The concept was developed to supplement the feed to the existing pebble crusher with a secondary crusher. Models of this process looked favorable so a portable crusher was installed to test the process. The temporary crusher was successful at increasing the throughput by 7% and based on the operating data, plans are currently being developed to install a permanent secondary crushing system in front of the SAG mill. This paper will review the results from the test crusher and the flow sheet for the permanent secondary crusher.

Jan 1, 2012

By D. Laguitton

The basic chemistry of a1•senic related to its dissolution and subsequent precipitation in gold-mine waste waters is discussed. The lime addition methods provides the most economic treatment of arsenical slurries, but requires a careful control of the oxidation of Asm into Asv, of the pH (>12) and the filtration of the precipitate. If arsenic levels below 0.5 mg/ l are required, a modification of the method by phosphate addition must be considered.

Jan 1, 1976

By Paul Graham

Presentation Focus ? What is LTUG / What do we do? ? History of LTUG ? Examples of Benefits from LTUG Participation ? Encourage Participation What is LTUG? ? An informal gathering of surface mining companies to discuss and work issues of common interest and to share information and best practices around large tires.

May 1, 2008

The fracture behavior of second phase particles and the role of matrix material on the wear resistances of the three Al-Si alloys containing 8, 17, and 19% Si were investigated using single pass scratch testing technique by applying normal loads between 0,15 and 5,00 N, in ambient air, Optical microscopy and SEM with EDS were used to analyze microstructures and morphologies of scratch tracks of the Al-Si alloys, The results showed that needle-like Si particles fractured under a load of 0.50 N, while block-like Si particles fractured at loads above 3,00 N, The Al-17% Si alloy with large number of needle-like particles (area fraction 16,4%) exhibited the highest coefficient of friction (0,8) and the widest scratch track, The Al-19%Si alloy containing high Si percentage and larger number of block-like particles (area fraction 16%) exhibited the lowest coefficient of friction (0,37) and the narrowest scratch track width. Presence of block-like particles was effective in reducing the amount of material transfer from Al-Si alloy surfaces to the counterface.

Jan 1, 2005

By R. E. Phelan

Introduction The Flin Flon deposit was discovered by Tom Creighton, an experienced prospector and trapper, who in 1914 made his headquarters at The Pas, Manitoba, and still lives there. The discovery was made in the fall of 1914, and Creighton and his associates spent the next summer in investigating the find. In August of 1915 the first claims were located. The property was optioned to Hayden Stone & Company, and in the spring of 1916 they started a diamond-drill campaign. Hayden Stone spent $50,000 on the property and, among other things, completed over 7,500 feet of diamond drilling. The ore not being as high grade as expected, and also being complex in character, Hayden Stone then abandoned their option. In the spring of 1917, Messrs. Earle, Faskin and associates took an option on the property and started an extensive drilling campaign. This campaign accomplished approximately 18,000 feet of drilling and secured for the Faskin interests a 32 per cent interest in the property. In 1920, W. B. Thompson and The Mining Corporation of Canada secured an option, and, while this option was in force, sunk two shafts in the ore-zone and did a considerable amount of drifting and cross-cutting in the ore to study the manner in which it occurred in place, and, by actual channel sampling, to check the grade indicated by the previously accomplished diamond drilling. All of this work had indicated that an ore-body existed on the property containing at least 18,000,000 tons of ore, assaying as follows: gold, 0.074 oz./ton; silver, 1.06 oz./ton; copper, 1.71 per cent; and zinc, ). 45 per cent (1). Complete analyses of composites from the drill holes showed that the ore was very complex in character. It contained the above values in gold, silver, copper, and zinc, as well as large amounts of sulphur and iron, and traces of lead, arsenic, antimony, cobalt, and various other metals. Although the ore was obviously pyritic in character, pyritic smelting, the usual method of treating this class of ore, could not be used to beneficiate the ore with any reasonable expectation of making such a venture a financial success, since coke and coal landed at Flin Flon would be expensive, and siliceous flux was known to be scarce locally and low in grade. The property therefore lay idle until 1925.

Jan 1, 1935