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By M. S. Badollet, N. W. Edgerton

"A study of the physical properties of long grades of asbestos fibers imported into the United States during the past eight years has disclosed information that will contribute materially to effective selection and use of fibers for electrical products. The study embraced fiber lengths, volume resistivity under three different conditions, total iron by chemical analysis, magnetic rating, conductivity of an aqueous ex-tract and its sodium chloride equivalent.The fibers examined included chrysotiles from Rhodesia, British Columbia, and Barberton area; marlime from Bechuanaland and Province of Quebec; amosite and crocidolites from Africa and Australia; and anthophyllites from Mozambique and from Georgia in the United States. Volume resistivity values provide a relative basis for estimating the electrical performance of end products; magnetic rating -an estimate of the quantity of iron compounds present in excess of those in the asbestos structure; conductivity of an aqueous extract; and an estimate of the ionizable impurities in fibers.Tests of these factors yield in-formation, not heretofore generally known, which may serve as a guide in the evaluation of asbestos fibers for electrical products."

Jan 1, 1960

By Holt. Grover J.

"IntroductionThe history of iron ore production in the United States has followed a pattern not far different from that set in the production of non-ferrous ores; the first interest of the prospector and miner being the discovery and development of high-grade ores. In the early stages of development of most mining districts, high-cost low-grade ores are usually of slight interest due to the additional capital investment required in concentrating plants, as well as the increased requirements of •power and other facilities. As the reserves of higher grade ores are depleted and the technical knowledge of ore beneficiation is broadened, production of concentrates from the lower grade ores is stimulated.The real stimulus necessary to arouse serious consideration of beneficiated iron ore in the Lake Superior district has been provided by the serious inroads made in the high-grade ore reserves by two World Wars.The first shipment of high-grade iron ore from the Mesabi range in Minnesota was recorded in 1892, and the first token shipment of concentrates was made 15 years later, in 1907. Not until 1910 did the production of concentrates assume any great importance. A steady increase in concentrate production over the years is shown by the fact that, in 1910, concentrates accounted for 8 per cent of the total shipments from the State, whereas by the time of World War II this percentage had increased to 22 per cent and by 1948 had risen to 26 per cent. It seems a safe assumption that the shipment of concentrated iron ore, from the Mesabi range in particular, will continue to increase even more rapidly from now on, with other iron ranges of the Lake Superior district following this lead."

Jan 1, 1950

By Brian W. Mackenkzie, Jozef Lajzerowicz

This paper is intended to familiarize planners in the noncommunist world with the district planning approach used in eastern Europe for mining development. It deals generally with the basic nature of the district planning problem, the planning process for mining development and the state organization for the planning of mining districts. A number of applications of district planning techniques to both established and new eastern European mining districts are described.

Jan 1, 1971

By S. P. Narayan

The hot deformation behavior of Pure Mg and Mg-0.29Ce alloy were studied by isothermal hot compression tests in the temperature range of 250 - 500°C and strain rate range of 10-3 - 102 s-1 in a computer-controlled 50kN servo hydraulic universal testing machine (UTM). The results show that the flow stress of Mg pure and Mg-0.29Ce alloy increases with strain rate and decreases after a peak value, indicating dynamic recovery and recrystallization. Process efficiency was increased by nearly 10 to 12% by addition of Ce in Mg. Mg pure exhibits instability zones between 250-275°C at 10 ? 102 s-1 and 400¬500°C at 101 ? 102 s-1 temperatures and strain rates respectively, rest is the safe deformation zone. Wherein, Mg-0.29 Ce exhibits two low efficiency zones from 250 ? 300°C at 10-2? 10° s-1, 400 ? 500°C at 101 ? 102s-1 and high efficiency zone at 450 ? 500°C at 10-3? 10-1s-1. 4D process maps were generated for the above said alloys which illustrate contours of power dissipation and instability in the 3D space of strain rate, temperature and strain.

Jan 1, 2011

By P. Leo

Al-Mg-Si alloys are widely used as medium-strength structural materials; extrusion is the most common processing route. In the present hot deformation investigation of a 6060 alloy, the microstructure of the alloy has been analyzed in the as-cast state, after homogenization heat treatment and after hot deformation by tensile tests in the range 400-490°C and 10-4 to 10-2s-1 on both as cast and homogenized alloys. After deformation the microstructure of the as-cast alloy exhibited cavitation. The flow curves at the lowest test temperature T show a gradual softening after a stress peak, being more evident for the alloy deformed in the homogenized state in association with a high yield stress; at higher T a plateau is attained which is lower as T rises and strain rates decrease. For each fixed T, the ductility decreases as strain rate increases for the homogenized alloy whereas, for the as cast alloy, it rises with strain rate. Constitutive analysis gives Q = 240kJ1mol for the homogenized alloy in agreement with published values; this indicates a more rapid strength decline with rising T than Al, suitable for good hot workability along with the lack of cavitation.

Jan 1, 2011

By Georges Croisé, Les-Lee Thompson, Adrien Debergé

Membrane filtration systems have regained focus in recent years as an effective means of liquid-liquid separation to increase the concentration of valuable elements, recover reagents or remove impurities. ORANO Mining (formerly AREVA) investigated this cost optimization process opportunity as early as 2011 for implementation at the Trekkopje project (Namibia). The key focus was to separate and recycle bicarbonate from the uranium bearing eluate solution. The performance targets were successfully achieved at lab- and pilot scale with an ultrafiltration and nano-filtration configuration system. Early 2015, ORANO Mining further launched an investigation into the use of membranes for acid recycling at the KATCO In Situ recovery mine in Kazakhstan based on the favorable results from the original bicarbonate application. KATCO is the world leader in ISR uranium mining with an eluate processing capacity of 80 000 m3/yr. This site consists of two processing plants namely, Muyumkum and Tortkuduk, located 40 kilometers apart, both operating under acidic conditions whereas precipitation and packaging are based in Tortkuduk only. This paper serves to present the results from the integration of a nano-filtration system at the Muyumkum satellite processing plant. The project consisted of screening laboratory bench studies conducted at ORANO-CIME followed by process validation at KATCO through further bench and pilot test work. The feasibility study assessments were successfully concluded which led to the implementation at an industrial scale in Muyumkum of a nano-filtration process to reduce eluate volumes being sent to the uranium precipitation section whilst achieving effective separation of uranium from sulfuric acid. Nano-filtration technology has drawn significant attention due to the efficiency and reproducibility of the process and its moderate capital cost relative to operational savings. The reliability of the previous results is a great opportunity to reduce operative expenditures within ORANO’s next ISR mining project in Mongolia.

Jan 1, 2020

By P. D. R. Maltby

This paper describes the background and markets for calcium carbonate and silica sand in Canada, as well as the results of recent test work carried out at the Ontario Research Foundation. Tests on sericite, tremolite, vermiculite, barite and graphite are also mentioned.

Jan 1, 1979

By William Petruk

Image analysis studies were performed on mill products from pilot-plant and laboratory tests that had been conducted to determine the effect of grinding media on the selective flotation of two zinc-lead-copper ores. It was found that, when the ores had been ground to the same degree of fineness with flint pebbles, ceramic pebbles or ore fragments (autogenous grinding) as with steel balls, there generally was increased sphalerite, chalcopyrite and galena liberation in the flotation feeds, depending on the textures of the minerals. The increased sphalerite liberation fully accounted for the improved zinc recoveries that were obtained when steel balls were replaced by either pebbles or ore fragments. The increased chalcopyrite and galena liberation accounted for part of the changed technical efficiency of concentration, but other factors, probably changes in oxidation and reduction of iron and in consumption of oxygen, also contributed.

Jan 1, 1977

By Andrukaitis. E.

The increasing use of electronic equipment by the Canadian Forces has increased the importance of electric power. A power source that is packed with energy and yet light, small and durable is the common request of military users. However, this needs to be achieved while also addressing the requirements of safety, reliability and low temperature performance. The potential use of fuel cells in a military environment has become a possibility in several areas in the 21st century. Some examples of power source requirements and the materials related R&D required to give better, higher energy power systems in the future will be discussed.

Jan 1, 2005

By S. Kariyawasam, R. McNealy

Pipelines are subject to multiple threats often requiring quantification of pipeline risk and engineering evaluation of in-line inspection and other data to effect discovery of conditions defined by the regulation. Public concern and pressure from regulatory bodies are accelerating the need for pipeline operators to formalize and intensify their approach to integrity management. Most operators need a phased approach to progressively adopt the most relevant and needed assessments. The organized and relevant assessment steps need to be introduced according to data available and maturity of the integrity management program. Each refinement to the quantification offers distinct advantages to the user. In this paper, the progressive integrity assessment solutions using quantitative methods are presented. Methodologies for engineering evaluation of integrity in-line inspection data for immediate and future integrity are summarized. Corrosion is used as an example, but the approach is applicable to any time-dependent defect based hazard. Strategies for pipeline integrity management are discussed.

Jan 1, 2005

By Raymond S. Suglo

Increasing depths of mining coupled with the mechanization of most underground mining operations have led to growing complexities in the mine environments with the production of large amounts of gaseous and particulate contaminants. Over 100,000 lives have been lost due methane gas and dust explosions in coal mine workings in both the US and Canada since 1900 when the methane concentrations exceeded stipulated levels in some workings. There is therefore the need to constantly assess and evaluate the performance of the existing mine ventilation systems to maintain safe and acceptable mine environmental conditions in workings to meet the requirements of federal, state or provincial laws. This paper uses the results of continuous monitoring of methane concentrations conducted in selected development headings in coal mines in North America to assess the effectiveness of existing auxiliary ventilation systems in the control of methane gas concentrations in the headings. The results show that the average quantities of fresh air required to dilute, disperse and remove methane concentrations within set levels of one minute varied from 5.43 m3/s in Heading #11 (Condition 2) to 27.97 m3/s in Heading #10 (Condition 1) and this represented about 12 to 26% of the quantities required to dilute methane concentrations to safe levels within one minute under Condition 1 and 32 to 139% under Condition 2. The average dilution times in the headings studied were less than 8 minutes. The forcing efficiencies of the auxiliary systems in the headings studied ranged from poor to excellent implying that the auxiliary ventilation systems were capable of controlling the methane concentrations below statutory levels but may not be able to cope with large and unusual methane concentrations in the headings. This study is important to prevent methane gas and coal dust explosions in coal mines and thus avoid any loss of lives and property.

May 1, 2001

By W. J. Wolfe

"Quartz Hill is a large, low- to moderate-grade quartz vein stockwork porphyry molybdenum deposit, discovered in 1974 during a regional stream sediment geochemical reconnaissance survey of southeast Alaska conducted by United States Borax and Chemical Corporation. Mineralization is localized in the upper parts of an Upper Oligocene (30 Ma) composite quartz monzonite stock which is emplaced discordantly into older Cretaceous to Early Tertiary terrain of the Coast Range igneous metamorphic complex of the northwest North American Cordillera. Subsequent fault-controlled, complex multi-stage intrusion, concentrated in the core of the Quartz Hill stock, produced successive pulses of hydrothermal alteration and molybdenum mineralization at about 27 Ma. Overall, the deposit is tabular and flat-lying and well suited to open pit mining. The 0.05% MoS2 grade limit covers an area of approximately 1500 m by 2750 m and extends to a maximum depth of 520 m below surface. Details of grade distribution show two separate lobes of higher grade material within the larger low-grade deposit.A ten year program of exploration drilling, underground development, sampling and metallurgical testwork led to a 1983 feasibility study based on a resource of 1600 million tonnes grading 0.127% MoS2 at a 0.08% MoS2 cutoff The large size of the deposit and its homogeneous grade distribution, typically showing gradual outward decrease of grade, makes in pit grade selection practical at several cutoff levels. Cominco Ltd. now reports a Probable Resource of 210 million tonnes averaging 0.22% MoS2 with a further Possible Resource of 1100 million tonnes averaging 0.12% MoS:z. At low molybdenum metal prices which have persisted for 10 years since the molybdenum price spike of the late 1970s and early 1980s, the Quartz Hill deposit is sub-economic."

Jan 1, 1995

By Engineering Staff

"This paper briefly describes the surface mining operations at Smoky River Coal Limited (formerly McIntyre Mines Limited, Coal Division) near Grande Cache, Alberta. Geology, mining methods, equipment, manpower and reclamation and environment topics are discussed. Introduction Smoky River Coal Limited, a wholly-owned subsidiary of McIntyre Mines Limited of Calgary, Alberta, produces a high quality, low sulphur, low volatile bituminous coking coal from its minesite located at west central Alberta, approximately 20 km from the town of Grande Cache and 360 km west of Edmonton (Fig. I). Most of the coal property is contained within a 30 km long by 20 km wide block lying in a northwest-southeast direction in mountainous terrain. Elevations vary from 920 m above sea level ·at the plant·site on the Smoky River to 1,600 mat the upper levels of current and proposed mining operations. A total of 11 coal seams have been identified. Only two seams, No. 4 Seam and No. 10 Seam are currently considered of major commercial value. These seams are recovered by both surface and underground mining. Approximately 650Jo of the plant feed coal is obtained from a conventional shovel/truck surface mine; the balance is mined underground by room-andpillar methods. Background In 1921, McIntyre Mines Limited acquired some 26,300 hectares of coal leases at Smoky River. Since then the leases were explored intermittently by different companies including McIntyre. In the mid-l 960s exploration activities increased and several feasibility studies were completed. Development of the area was undertaken by McIntyre in 1968 and, in August of the same year, a long-term contract was signed with a consortium of Japanese steel mills for delivery of 2 x 106 t of clean coking coal for 15 years commencing in 1970. Production was focussed on underground mining, using longwall methods."

Jan 1, 1985

By Robert A. MacGregor

"Following several months of test work, water leaching in mined-out areas at Stanrock commenced on a production basis in February, 1963. A combination of fast high-pres-sure washing and rewashing of stopes on a predetermined cycle, and the intermittent sprinkling of low-grade heaps, using both fresh water and recirculated acid water, has proved most successful. There was also a correlation of daily sampling data points to a relationship between the leach water grade and the grade of the material being washed, the leaching time and the location along the dip. An increasing tolerance for uranium by the acid-producing bacteria is also indicated. A steady production rate of 10,000 to 12,000 lbs. of u.08 per month is being maintained, with an over-all mine water grade of 0.25 lb. per ton and a pH of 2.3."

Jan 1, 1966

By B. R. Conard

Copper refining at Vale Canada (previously known as Inco) has been associated with Ni production. Because Cu and Ni carry risks for adverse health endpoints through inhalation exposure, it is critical that their aerosol levels, and the metallurgical processes through which they enter the air, are understood. Because certain Ni substances have been linked to respiratory cancers, it is also important to characterize the amounts and types of Ni compounds in occupational settings. This paper describes electrorefining and electrowinning operations near Sudbury, Ontario (1930–present), and gives aerosol measurements (1978–present).

Jan 1, 2014

By Zhao-shu Sun, Mao-lin Li, Rui Cui

"Fankou Mine produced pyrite concentrate (PC) from the tailings by rougher and scavenger flotation before 2010, with the averaged S grade of 40.54% at recovery of 79.34%. The economic value of PC increases with its purity. When the S grade of PC feed to sulfuric acid plant is over 47%, the pyrite cinder can reach a high Fe grade of 62% which can be directly sold as iron concentrate. On this background, engineers in Fankou Mine set the PC with S grade of 47% as target.The direct way to reach that goal was to clean the rough PC Lots of cleaner flotation tests were conducted and the balanced strategy was to produce two ranks PC with the S grade of 47% and 38% at the recovery of 44.20% and 36.17%, respectively. The dual-product flowsheet was successfully industrialized in 2010. In order to further improve the quality of PC, gravity separation was introduced into the flowsheet. The numerical simulation and tests were performed to evaluate the beneficiation and classification performance of hydrocyclone as it treated the rough PC. It was shown that the underflow of hydrocyclone could addressed the S grade of 47%, and the finer size overflow could also be enriched to PC with S grade of 47% by flotation, due to the contained pyrite with well liberation. That is to say, with the ingenious addition of hydrocyclone to treat the rough PC, single PC with S grade of 47% could be achieved. The new flotation-gravity separation flowsheet was commissioned to produce the high quality PC at the end of 2013. The averaged S grade is 47.20% at recovery of 82.26% in 2014. The two steps flowsheet improvement maximizes the enterprise benefits and leads to simple utilization of Fe in pyrite in downstream industry."

Jan 1, 2016

By R. Wirth, B. Orberger, C. Wagner, A. Tudryn, B. Baptiste, S. Miska, Université Paris-Sud

Banded iron formations (BIFs) comprise complex textures and mineralogy, which result from fluid-rock interactions related to high and low temperature alteration. The initial iron oxy hydroxide mineralogy and associated phases such as carbonates, quartz, apatite and phyllosilicates were transformed leading to an upgrading of these BIFs into the world’s largest source of iron ore. In low-grade BIFs, a large part of the iron is related to micro- and nano- metric iron-bearing inclusions within micrometric quartz and/or carbonates (mainly dolomite). We studied laminated jaspilitic BIF samples from a drill core containing 26.71 wt.% total iron, 0.2 wt.% SiO2, 0.32 wt.% MnO, 15.46 wt.% MgO, 22.32 wt.% CaO, 0.09 wt.% P2O5, < 0.05 wt.% Al2O3, 0.15 wt.% H2O and 34.08 wt.% CO2 (Aguas Claras Mine, Quadrilatero Ferrifero, Brazil). Bright rose coloured dolomite and quartz bands alternate with massive specular hematite bands. Raman spectroscopy, X-ray diffraction and FIB-TEM analyses reveal that the micro- and nanometric inclusions in dolomite are mainly hematite and minor goethite, partly occurring as clusters in voids. Curie Balance analyses were carried out at different heating steps and temperatures on whole rock samples and a synthetic mix of decarbonated sample and pure dolomite. X-ray diffraction on the products of the heating experiments shows that that hematite is stable and new phases: magnesioferrite (MgFe2O4), lime (CaO), periclase (MgO), portlandite (Ca(OH)2) and srebrodoskite (Ca2Fe2O5) were formed between 680°C and 920°C. These finding gives hints to optimizing the beneficiation process, as the presence of hydroxyl ions bearing goethite micro- and nanoinclusions lowers the sintering temperature. Prior separation of coarse hematite and barren dolomite and quartz, followed by lower temperature sintering of the inclusionbearing dolomite/quartz leads to transformations into phases with higher magnetic susceptibilities (such as hematite and magnesioferrite). The entire Fe and Fe/Mg oxide feed (the priorly separated fraction added to the sintered fraction) can then pass through wet-high intensity magnetic separation after crushing.

Jan 1, 2016

By R. Hendricks

"IT IS a pleasure for me to appear before yon today and to have this opportunity of reviewing with you recent developments in the world lead and zinc industry. To provide essential background material, I propose reviewing the period from 1950 to the present, a period which has undoubtedly been the most hectic in the long history of the industry.In capsule form, the pattern for this period is one of repeating cycles of boom and recession, of failure through research to develop adequately new markets and new uses for lead and zinc, of surplus production and growing inventories, of price instability, and lastly, of an abdication in some sections of the industry of responsibility for control of its own destiny by turning to governments for support in time of stress. This is not a pretty picture but, as the 1950 decade ends, there are signs of a new maturity and of a growing determination on the part of the industry to put its own house in order.The difficulty suffered by the world's lead and zinc industry in the current decade originated with the support extended to it in 1950 by the U.S. Government at the time of the Korean conflict. Recalling the shortage of base metals in World War II and fearing that the Korean conflict might develop into World War III, the U.S. Government in 1950 adopted a policy to encourage the production of lead and zinc, both domestically and abroad by means of development loans and long-term floor priced purclu.se contracts."

Jan 1, 1960

By J. C. Gathje

Newmont&apos;s Phoenix Project is located near Battle Mountain, Nevada and is scheduled to produce copper concentrates containing high precious metal values. High temperature pressure oxidation (PDX) of the concentrates was considered as a treatment option during process development. The metals content in Phoenix concentrates range from: 15-25% for Cu, 1-10% for Zn, 0-2% for Pb and ?27% Fe. The precious metals content of the Phoenix concentrates can range up to ?300 g/t Au and >3,000 g/t Ag. As a consequence it was necessary that any process for consideration should have the capability of recovering both the copper and precious metal values. Typically, gold can easily be leached from the autoclave discharge solids, but silver is chemically bound with the jarosite formed and cannot be directly leached. Laboratory investigations led to the development of a patented PDX process that minimizes the formation of jarosite so that the silver can be leached easily along with the gold. The process was confirmed with extensive pilot plant testing. Excellent solution extraction of copper and zinc was achieved, and both iron and lead were precipitated in the PDX residue. The process produces clean PDX discharge liquors with very low iron concentrations. As an example, conventional PDX techniques resulted in pregnant liquors containing ?5 g/L Fe. However, the Newmont process, which controls the iron and sulfate species, achieved high iron precipitation in the PDX solids and pregnant liquors containing <0.5 g/L Fe. High gold and silver recoveries were achieved by direct cyanidation of the PDX solids. This process has the added benefit of producing PDX solids that demonstrate superior settling and filtration characteristics.

Jan 1, 2006

By Ltd. (CYMCO) Technology Center Yunnan Metallurgical Group Co., S. Jian, T. Song, J. D. Miller

"As sulfide zinc ore deposits become exhausted, nonsulfide zinc ore deposits become the other resource for zinc production. However, flotation for zinc recovery from nonsulfide deposits is much more difficult than the flotation of sphalerite from sulfide deposits and may become an option for zinc production only if a suitable processing technology is developed. In this regard, research efforts are being devoted to the flotation of nonsulfide zinc oxide minerals. Some common methods which have been used for the flotation of zinc oxide minerals include sulfidization-flotation, activation, and direct flotation with anionic and cationic collectors. The traditional flotation techniques have low efficiency and difficulty in separation and recovery of the zinc minerals from gangue minerals, for example, smithsonite (ZnCO3) from other carbonate gangue minerals and hemimorphite (Zn4Si2O7 (OH)2·H2O) from silicate gangue minerals. In this study potassium lauryl phosphate was evaluated as a collector for the flotation of nonsulfide zinc minerals. Results from contact angle and microflotation experiments at pH 6–9 show that hemimorphite (Zn4Si2O7 (OH)2·H2O) can be floated from quartz and that smithsonite (ZnCO3) can be floated from calcite. However, when dodecylamine, which is a common collector reported in literature for the flotation of nonsulfide zinc minerals, was used as collector, no significant difference between nonsulfide zinc minerals and gangue minerals was observed at any pH value. Initial evaluation suggests that potassium lauryl phosphate is effective at low concentration and may be a promising collector for zinc oxide mineral flotation.INTRODUCTIONBefore the twentieth century, zinc was mainly produced from nonsulfide ores (Large, 2001; Gilg, Boni, & Cook, 2008). With the development of differential flotation processes in the late 19th century major production switched from nonsulfide zinc sources to sulfide zinc ores (Hitzman, Reynolds, Sangster, Allen, & Carman, 2003; Gilg et al., 2008). However, as it is becoming more difficult to find new sulfide ores, recovery from nonsulfide deposits is being considered. Nonsulfide flotation for zinc recovery is much more difficult than the flotation recovery of sphalerite from sulfide deposits and may become an option for zinc production if a suitable technology is developed. Zinc and lead oxide ores are difficult to beneficiate ores due to their similar floatability with gangue, high solubility in water, and the influence of slimes (Fa, Miller, Tao, & Li, 2005). In order to improve the performance of oxidized minerals, lots of effort is being devoted to this field of study (Ejtemaei & Mahdi, 2014)."

Jan 1, 2016