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By H. R. Wilson

"This paper describes the evolution of the Waste Management Program at the Lupin Mine through the years 1982 - 1988. The program was developed in response to the terms and conditions of the Water Licence issued to the mine in 1981 by the Northwest Territories Water Board. Echo Bay Mines Lupin Mine is located on the western shore of Contwoyto Lake in Canada's Northwest Territories about 80 km. south of the Arctic Circle.The gold mine commenced production in 1982 and the Waste Management Program was based originally on the total containment concept. Due to an expansion of the mill circuitry and increased throughput, it was apparent that the total containment concept would require reevaluation since discharge from the pond would be required within a few years. During the initial years of production, an investigative program was established to determine the most effective means for treating the tailings pond water. This program incorporated both laboratory studies as well as monitoring of the tailings pond contents and environmental conditions as the impoundment area was filling. The program showed that natural degradation phenomena, if properly utilized, are effective in lowering the concentrations of all contaminants to within Licence limits with the exception of arsenic. To ensure compliance with arsenic limits, an iron salt was added to cause arsenic to precipitate from solution in the tailings pond.As a result of our studies, the tailings management system finally implemented at Lupin Mine includes the following components:Tailings pulp retention cells constructed by dyking off one end of the tailings impoundment area.Two tailings ponds in series operated in a sequential decant and fill fashion.An iron salt solution preparation and metering system.A syphon system into which the iron salt solution is injected as the contents of the first pond are decanted into the second pond.A second syphon system for decanting the contents of the second pond to the receiving streamThis paper discusses the findings and conclusions of the waste management investigative program, describes the civil work completed to reach our final operating scenario, describes the sequence of operating the treatment system, reviews performance data, and comments on abandonment and restoration of the tailings impoundment area."

Jan 1, 1989

By I. M. R. Duarte, J. A. Rodrigues-Carvalho, F. R. S. Rosa, A. B. Pinho

"This paper aims to contribute to the knowledge of the mechanical properties of the shales and greywackes which constitute the flysch-type deposits of the Baixo Alentejo Flysch Group, in the south of Portugal. These formations are flysch-type deposits constituted by sequences of usually thick greywacke beds alternating with thin shale beds, which include sometimes intercalations of conglomerate beds. All the sedimentation of these flysch formations was controlled by tectonics. At the same time, should have occurred along with the first Hercynian deformation phase, a low-grade metamorphic event (chlorite zone), that affected these flysch deposits. This study highlights the influence of anisotropy and heterogeneity of these flysch rocks on their physical and mechanical characteristics. The anisotropy verified in some physical properties and on mechanical properties, due to the foliation makes difficult the sample preparation for the laboratory tests. Besides, it induces a scattering of the properties values measured, as for example, the strength and the deformability. The heterogeneity is related to the main features of these geological formations, which are constituted mostly by thinly stratified greywackes and shale beds, which sometimes may affect the results of the laboratory tests making them less representative. The study is made by using both shales and greywackes that constitute these flysch-type deposits in order to evaluate their geotechnical properties, mainly of the shales. Samples of these two rock materials, are tested accordingly a laboratory testing programme, which includes which included mineralogical analysis (X-ray diffraction), physical tests (bulk density, porosity, and void index) and mechanical tests (uniaxial compression, and deformability tests). INTRODUCTIONOne of the factors that most influence the geomechanical behavior of rocks, as well as rock masses is the anisotropy. The word anisotropy comes from two Greek words ""anisos"" (meaning uneven) and ""tropos"" (meaning direction). A body or material is considered to be anisotropic, where the same property has different values depending in which direction it is measured, therefore, an anisotropic material is one whose magnitude of the properties depends on the direction in which these are studied or measured. Otherwise, it is about an isotropic material. However, the fully isotropic materials are quite rare in nature."

Jan 1, 2015

By J. Fellowes, Z. Liang, J. Robson, M. Kenyon

"Dispersoids play a significant role in the recrystallization and texture development for wrought Al-Mg-Si (6xxx series) alloys by inhibiting grain boundary motion. It is therefore important to understand the precipitation kinetics of such particles. It is the additions of Mn and Cr in Al-Mg-Si based systems that can lead to dispersoid phases being formed. These phases are currently thought to nucleate on ß’-Mg2Si via an intermediate semi-coherent precipitate. Scanning transmission electron microscopy (STEM) has been conducted to study the precipitation of a-Al(CrFe)Si and a’-AlCrSi dispersoids. Corresponding electron dispersive spectroscopy (EDS) has been used to distinguish the dispersoids. The volume fraction and size distribution of dispersoids has been measured as a function of distance across a grain. Electron probe microanalysis (EPMA) has been conducted to study the inhomogeneity of elements in the cast structure and the effect on dispersoid precipitation. Dispersoid free regions have been observed in the microstructure correlating to regions depleted in the dispersoid forming elements.INTRODUCTION Al-Mg-Si (6xxx series) based alloys are increasingly being used in the automotive industry. The primary reason is to reduce the weight of vehicles, resulting in a reduction of CO2 emissions and increased fuel efficiency. The demand for 6xxx series is predicted to increase over the coming decade. Due to the high cost and CO2 emissions produced by raw extraction of aluminium, close loop recycling of these alloys becomes a more important process. However recycling of automotive alloys can be difficult due to pick up of impurity elements such as Mn, Cr and Fe. The addition of these elements can form dispersoid particles during early heat treatment processes. Although a controlled population of dispersoids is necessary to control the grain structure during thermo-mechanical processing, a significant change to the dispersoid population due to a composition change could profoundly influence the final microstructure, affecting the final properties of the material. More research is required on the precipitation and effect of additional minor alloying elements; in order to increase the 6xxx series alloys recyclability."

Jan 1, 2018

By S. Broda

Waste rock piles (WRP) are made of heterogeneous, coarse grained waste rock, with inclined layers due to segregation along the slopes and haul traffic compacted layers, creating highly contrasted hydrogeological conditions. The internal structure of the pile has a major impact on water and oxygen movement and pore water pressure distribution. In the presence of reactive minerals, this influences the production of acid mine drainage (AMD) or contaminated neutral drainage (CND) with metal leaching from the WRP. Water flow and distribution may also affect slope stability, particularly following major infiltration events (rain/snow melts).The prediction and interpretation of water distribution in WRP is a challenging problem. Numerous numerical investigations of short and long term forecasts have been conducted, and many of these were found of limited reliability. The shortcomings of existing approaches are typically due to difficulties in representing preferential flow processes in macropores. Such phenomena are in fact often neglected in the assessment of water flow in WRP because these are unattainable with the classical porous media approach typically used in this field. This paper focuses on the use of modeling techniques originally designed for massive fractured rock media to simulate flow in WRP. Waste rock properties used in this study are retrieved from large scale laboratory permeability and water retention tests and from in situ infiltration tests. The effect of WRP configurations on water flow into potentially reactive zones is examined with the numerical 3D fully-integrated surface/subsurface, variably saturated flow model HydroGeoSphere. Material properties retrieved from the laboratory tests are represented by means of stochastic facies distribution generated within a probability framework. Modelled soil water contents and hydraulic head distributions, as well as fluxes within a simple waste rock pile, with compacted layers, are compared with results retrieved from simulations based on the classical equivalent porous medium approach. Results indicate significantly increased flow towards the looser waste rock zone by considering heterogeneous material distribution, causing weak or absent capillary barriers and preferential flow paths. Practical implications for the design of waste rock piles are also discussed.

Aug 1, 2013

By N. Melnyk

"FOREWORDThis paper provides a unique description of a method devised for mining a very thick steeply dipping seam of soft gassy coal which was prone to spontaneous combustion. The editors con¬sider that the information in this paper should be important to those who may have to consider mining such seams again at some time in the future and therefore believe that the paper warrants reprinting in the present volume. The author was ask¬ed to review the paper and to add any additional relevant in¬formation. He provided the accompanying footnote, only a month before his death on April 22, 1982.IntroductionIn the past, the Cadomin Coal Company has opened four mines, all in the same coal seam or its folds. Three of these were opened from river level by horizontal entries or rock tunnels. and the fourth, the present working mine, by vertical shafts. This paper deals largely with some operating phases of this fourth mine, with which the writer has been associated.The seam worked here is a thick, steep, bituminous seam, and the writer feels there is a paucity of published data on the mining of such seams. Possible reasons for this are that such seams do not lend themselves to intensive development or mining, there is little chance to mechanize because of the extreme pitch, and operations are fraught with many problems. In addition the present operations in this particular' seam are being carried on at a level below the former workings, introducing new problems, not encountered on the upper level.Coal will, without question, long continue to be an impor¬tant factor in the national economy, and some of the best coal is to be found in thick, steep seams. But with the exhaustion of the easily-mined coal near the outcrops, future coal will have to come more and more from lower levels. At Cadomin there is still considerable coal on the second level, below the old river-workings, and there is a possibility that, in the future, still lower levels will be worked. It is the purpose of this paper to indicate some phases of such lower-level operations and to invite discussion."

Jan 1, 1985

By M. Clotilde Apua, A. F. Mulaba-Bafubiandi

"The efficiency of hydrochloric acid (HCl) leaching of gold from low grade gold-bearing material has been investigated in the presence of sodium hypochlorite (NaOCl) to produce in situ chlorine gas which is an oxidizing agent able to oxidize gold metal to its soluble forms. The effect of concentrations of HCl, NaOCl, and mixtures of HCl + NaOCl was sought. Iron and potassium present in the feed were leached and consumed all the HCl. Gold found as inclusion in pyrite was not exposed to the lixiviant. Therefore, leaching of gold from low grade gold-bearing material in aqueous chlorine solution is not an effective process for now.INTRODUCTIONHydrometallurgy of gold is commonly based on cyanide leaching solution. Due to the environmental concerns related to cyanidation and mercury processes, and inefficiency of cyanide gold leaching to dissolve refractory ores, sustainable alternative lixiviant systems, capable of generating gold (I) and gold (III) complexes must be studied. Amongst non-cyanide gold lixiviants there is the chloride/chlorine system (Hilson and Monhemius, 2006; Senanayake, 2004; Pilsniak and Trochimczuck, 2007; Wang et al., 2007; Reeves et al., 1999; Khodadad et al., 2008).In practice, the most oxidizing agents utilized for the leaching of gold as chloride, are chlorine (Cl2) or hypochlorite (HOCl) which are either generated in situ by suitable reaction or added in solution (Adamson, 1972). The dissolution of gold concentrate using hydrochloric acid, sodium chloride and sodium hypochlorite (Cl-/HOCl system) were studied (Puvada and Murthy, 2006). The effect of NaOCl and NaCl concentrations were also investigated. The leaching was performed under the following conditions; time: 4h, solid–liquid ratio = 1:4, at room temperature. It was found that the increase of the NaOCl concentration from 25 to 75 g/L did not have any meaningful effect on the recovery of gold which was about 30% (experimental conditions; S/L ratio = 1:4, NaCl concentration: 25 g/L, HCl concentration: 0.35 M). It was also found that from 25 g/L to 200 g/L NaCl, the recovery of gold rose from 30% to 40% (experimental conditions; S/L ratio: 1:4, NaOCl concentration: 25 g/L, HCl concentration: 0.35 M)."

Jan 1, 2012

By A. L. Mackie

Arsenic is a highly toxic element and a known human carcinogen. It is often a contaminant in mine water discharges, particularly from gold mining and roasting operations, and has been found at concentrations as high as 4 g/L. Increasingly stringent controls on the concentration of arsenic allowed to be discharged into the environment cannot always be met by current treatment processes and thus enhanced technologies are required to achieve low treated effluent concentrations at reasonable costs. A novel two-step physicochemical treatment process was developed and tested at the bench-scale using synthetic mine water solutions (SMWs) in order to reduce arsenic concentrations in treated effluent to exceed current discharge regulations. The process includes chemical coagulation with ferric sulphate and ballasted flocculation for enhanced solid-liquid separation. The SMW contained 59 ± 2 mg/L arsenic with a slightly alkaline pH. The effect of arsenic speciation on the process was tested by using either arsenite, As(III), or arsenate, As(V), in the SMW solutions. Tests were performed at cold temperature (3 ± 1 °C) to ensure the process? efficacy year-round in northern climates. Arsenic in As(V) SMW solutions was removed to a final total concentration of 0.0054 ± 0.002 mg/L, almost half the current recommended allowable drinking water concentration of 0.010 mg/L. As(III) was removed to a concentration below the Metal Mining Effluent Regulations? (MMER) current limit of 0.50 mg/L, to 0.32 ± 0.06 mg/L, with double the coagulant dose used in Stage 1 for As(V) removal. Oxidant addition at a concentration of 5 mg KMnO4/L in Stage 2 resulted in final total arsenic concentrations of 0.017 ± 0.002 mg/L and pH adjustment with lime in Stage 2 resulted in 0.0415 ± 0.0007 mg As/L in treated As(III) SMW. Both of these modifications to the process reduced arsenic concentrations to below proposed new MMER limits (i.e., 0.10 mg/L). This two-stage treatment process was shown to reduce arsenic concentrations to well below current treatment guidelines while reducing or eliminating chemical oxidant demand.

Aug 1, 2013

By A. Danaei, A. McLean, M. Barati, C. Ravindran

"The aluminum industry generates about 90 million tonnes of red mud each year. Previous research shows it could be utilized as a refining flux with a high capacity to absorb phosphorus and sulphur from hot metal in the steel industry. The present study was undertaken to evaluate the melting properties of such fluxes, as it affects the effectiveness of the flux. The results show that the melting behavior of red mud is strongly affected by lime addition and the characteristic melting/softening temperatures reach minimum VALUES (at 32.7 wt% CaO. From these findings, a correlation was established between melting behavior and optical basicity. This allows one to adjust the composition of the flux based on the process requirements. INTRODUCTIONThe aluminum industry generates about 90 million tonnes of bauxite residues each year. This residue is usually red in color because it contains a substantial amount of iron oxide. The red mud, as it is called, is a solid waste with a high concentration of sodium oxide, high pH (10 to 13), and high alkalinity, and thus is harmful to many forms of life. Traditionally, the material is stored in large tailings ponds within the plant’s vicinity (Power, Grafe, & Klauber, 2009). Development of solutions for safe disposal or preferably using this residue for other industrial processes or applications could help restore polluted locations and eliminate a negative impact on the environment (Haake, 1988; Power et al., 2009; Yan & Xuegong, 2010).The mineralogy and chemical composition of red mud depends on the quality of the bauxite and refining process parameters. In general, it consists of iron oxide (Fe2O3), aluminum oxide (Al2O3), titanium oxide (TiO2), sodium oxide (Na2O), silicon oxide (SiO2), and calcium oxide (CaO) (Power et al., 2009). Like most ores and soils, bauxite can contain trace quantities of metals such as arsenic, beryllium, cadmium, chromium, lead, manganese, mercury, nickel, and naturally-occurring radioactive materials, such as thorium and uranium. Most of these trace elements stay in the residue (Power et al., 2009)."

Jan 1, 2012

By R. A. Sudisman, T. Yamabe, M. Osada

"Geological material can be subjected to some different loading conditions, mainly due to three inter-related physical processes which are mechanical, thermal, and hydrological. Freezing and thawing process of rock that occurs in sub-zero temperature condition may contain some or all those three physical processes depended on its initial condition. Those inter-related physical processes may lead the ground into failures. Therefore, understanding the physical properties such as deformation process of geological material under freezing and thawing condition is required for the artificial ground freezing projects and engineering construction activity in the natural cold region.In order to study the strain characteristic of rocks during freezing and thawing process, a series of freezing and thawing experiments of core samples of three different rock types and mortar has been conducted under varying temperature from -20 °C to +20 °C. Four core sample types are Sandstone, Granite, Tuff, and Mortar with 50 mm diameter and 50 mm height, which were naturally dried before the freezing-thawing experiment. Freezing-thawing experiment was conducted by submerging the vinyl covered core samples into a temperature-controlled liquid coolant box. Firstly, temperature of liquid (brine solution) was set at -20 °C so that the temperature of subjected sample was decreasing to as low as -20 °C. And then the temperature of brine was returning to initial room temperature after the coolant system was stopped. Strain gauge and thermo couple were attached on the core’s perimeter to measure strains and temperature changes.Sandstone and Mortar samples show relatively similar results than other two samples. Both presents linearly shrink with the temperature decrease and expand almost to its initial condition with the temperature increase. Granite shows less-linear strain-temperature relationship during thawing process, while the Tuff sample shows abrupt strain increase during thawing process on the temperature higher than +10 °C. Thermal expansion value of each rock types were obtained by fitting the major strain-temperature relationship on -19 °C to +10 °C temperature range. Overall, anisotropic deformation was observed on the entire samples and possible mechanisms for each hysteresis characteristic are discussed, which need to be confirmed by further experiments."

Jan 1, 2015

By V. G. Papangelakis, A. Dani

"Alkaline pressure oxidation, particularly in the presence of trona as additive, can be used to oxidize high carbonate refractory gold ores as it prevents the formation of CO2 in the autoclave. However, the presence of silica in the ore can lead to the encapsulation of pyrite due to the solubility of silica in alkaline solutions and its subsequent reprecipitation on the reacting pyrite surface, leading to the formation of a passive layer. This fundamental study investigates the chemical composition and thickness of the passive layer on a rotating pyrite disk using XPS and SEM, as a function of process conditions at 230°C, in an aqueous slurry containing silica sand, sodium carbonate and calcium carbonate under 100 psi of oxygen overpressure.INTRODUCTIONAlkaline pressure oxidation (POX) has been used successfully to treat high carbonate refractory gold ores, which contain carbonates in addition to sulphides, most notably at Mercur and Goldstrike mines operated by Barrick Gold. There are several advantages to using alkaline POX over its acid counterpart, especially due to high carbonate content. First, it eliminates the production of CO2 in the autoclave without resorting to pre-acidification, which allows for high oxygen utilization. Second, alkaline POX suppresses the formation of elemental sulphur and intermediate sulphur oxyanions (such as thiosulphates and dithionates), which reduce gold recovery. Third, the use of sodium hydroxide or salts prevents the formation of anhydrite scale by forming soluble sodium sulphate. Other advantages are the use of cheaper materials of construction and the formation of non-acidic residue that do not require further treatment prior to cyanidation (Thomas, 2005).Sodium carbonate in particular is a promising reagent for alkaline POX because it was shown to significantly accelerate the kinetics of pyrite oxidation by molecular oxygen, when compared to other reagents such as sodium hydroxide, sodium borate and calcium hydroxide. This has been attributed to the following factors: a) the faster oxidation kinetics of Fe2+-CO3 complexes compared to Fe2+ oxidation, b) the buffering effect of carbonate ions on the acidic pyrite surface, and c) the increased solubility of oxidizing Fe(III) species due to carbonate complexation (Caldeira, 2010)."

Jan 1, 2012

By M. A. Perras, M. S. Diederichs

"The Niagara Tunnel Project (NTP) is a 10.1 km long water-diversion tunnel in Niagara Falls, Ontario, which was excavated by a 14.4 m diameter tunnel boring machine. The excavated rock types included limestone, sandstone, siltstone, shale and mudstone. Based on observations and measurements the overbreak was divided into four zones. Approximately half the tunnel length was excavated through the Queenston Formation, which locally is a shale to mudstone. Three of the four overbreak zones were within the Queenston. Zone 1 includes the formations above the Queenston Formation, Zones 2 and 4 are border regimes with little or no influence from St. Davids Buried Gorge and Zone 3 is the area influenced by the gorge. Zones 2 through 4 can be generally summarized as having overbreak as the result of stress induced spalling. Zone 2 marks the transition from slabbing at the Whirlpool contact in the stress shadow to spalling towards Zone 3. The behaviour of Zone 3 is interrupted from the typical high stress behaviour due to the presence of St. Davids Buried Gorge. As the tunnel passed from the gorge the high regional stresses induce spalling, which creates the typical notch shaped overbreak geometry of Zone 4.Three modelling approaches were used to back analyze the brittle failure process at the NTP: damage initiation and spalling limit, laminated anisotropy modelling, and ubiquitous joint approaches. Analyses were conducted for three tunnel chainages: 3+000, 3+250, and 3+500 m because the overbreak depth increased from 2 to 4 m. All approaches produced similar overbreak geometries to those measured. The laminated anisotropy modelling approach was able to produce overbreak depths and chord closures closest to those measured, using a joint normal to shear stiffness ratio between 1 and 2. The back analysis results were able to produce sets of stress and strength inputs for different sections of the tunnel at the transition from overbreak Zone 3 to 4. The back analysis procedure demonstrates the importance of including the anisotropic stiffness in the numerical modelling approach to correctly capture the overbreak geometry and deformations around underground excavations."

Jan 1, 2015

By H. J. McQueen

Aluminum was hot worked at 400 - 500°C and strain rates (e ) of 0.004 -0.1s-1, under reversing strains (c) of 0.5 to 0.2 or 0.5 to 0 and also advancing from 0.5 to 1 or 0.5 to 5. Under similar test conditions for different parts of the strain paths, the average measured flow stresses are found to agree with each other. In the forward and backward strain path tests, the almost identical steady state plateaus affirm the occurrence of dynamic recovery (DRV). On reversal of strain direction at constant e , there was generally negligible Bauschinger effect. In specimens annealed at 400°C, static recrystallisation (SRX) was followed microstructurally. mainly by disappearance of elongated grains with serrated boundaries because the new grains were only little a finer than the old due to low strain energy. The only influence of reversing strain path observed was the effect of change of grain boundary area as grains elongated or returned towards equiaxed. In optical microscopy, elongated grains with serrations and deformation bands confirmed DRV in forward path specimens. In reverse path specimens, equiaxed grains were gradually restored with retention of serrations and bands. In low magnification polarized optical microscopy, grain alignment increased with strain for forward path specimens; whereas it decreased in reverse path ones, supporting DRV. Orientation imaging microscopy (OIM/SEM) revealed that elongated grains are broken up as deformation bands rotate during the forward path and that grains return to equiaxed appearance on backward straining. Comparative studies using optical microscopy in polarized light (POM), OIM/SEM and transmission electron microscopy (TEM) revealed that while subgrains remain equiaxed and constant in size and character during the forward and backward paths, the fraction of low angle facets decreased while that of high angle grain facets increased with increasing strain; these are coupled with a fairly low fraction of medium angle boundaries. The results contribute to the understanding that dynamic recovery in aluminum maintains sub-boundaries with low misorientation but as grains elongate and more subgrain become adjacent to grain boundaries the fraction of high angle boundaries rises (with backward straining it was vice versa).

Jan 1, 2007

By Perry L. Christian

"Mana/ta Coal Ltd. 's Costello Mine, located seven kilometres east of Estevan, Saskatchewan, has been operating at the present location since 1960. During the past twenty-three years, annual production of lignite coal has averaged 590 000 tonnes. The coal is used for power generation and for industrial and domestic use. Markets, operating techniques, facilities in place and reclamation are discussed. Introduction The Costello Mine (formerly the Klimax Mine) is located in southeastern Saskatchewan, approximately 210 kilometres southeast of Regina and 5 kilometres from the United States' border, as shown in Figure 1. The present mine, 7 kilometres east of the city of Estevan, has been operating since 1960. The history, however, of the Costello Mine and of the Estevan Coalfield dates from the initial settling of the area in the 1880s. Mining initially consisted of burrowing into the side of the Souris River Valley or other hillsides where the coal seam was exposed. Eventually, slopes were put down in the Estevan/Bienfait area and vigorous underground activity existed. In the late 1920s surface strip mining was introduced. The use of strip mining progressed to the point where it completely replaced underground mining in the 1950s and it is the only method in use today. During the past 23 years annual production has averaged 590 000 tonnes. The lowest production was in 1960 when the mine was starting up at 167 000 tonnes and the highest production was in 1977 when production was 1 509 000 tonnes. The Costello Mine controls approximately 11 400 hectares of mineral rights in the Estevan area. This is made up of 4 900 hectares of freehold coal and 6 500 hectares of leases. The area forms a large, irregular shaped configuration. Most holdings are contiguous and adjacent. The mine also owns some 8 400 hectares of surface rights. The lands under the Costello Mine's surface rights control, which are not being used in the mining operation, are leased to local farmers and ranchers. This ensures that the land is used to its full potential, both before and after mining."

Jan 1, 1985

By T. L. Tanton

Introduction Sturgeon River area, on the east side of lake Nipigon, Ontario, was the scene of a gold rush in 1934. According to press reports, the active staking during the latter part of the summer spread out rapidly from the early holdings until it embraced practically all of the lower basin of Sturgeon river in a belt up to ten miles wide extending west from Kinghorn for 35 miles to lake Nipigon. And, before winter set in, active prospecting and claim staking reached beyond lake Nipigon to areas where belts of ancient schists were known, notably west of Obonga lake. The writer's familiarity in past years with the areas to which attention has been directed admits of some observations on means of access in the field, the general geology, and the progress that has been made in identifying formations favourable for the occurrence of gold. Canoe Routes From the writer's observations in Sturgeon River area in 1917 and in the Obonga Lake area in 1933, it is recalled that there is, locally, a striking dif~ ference in the accessibility of the two areas by travel along canoe routes. Sturgeon River area is easily accessible from Kinghorn or Jellicoe stations on the Canadian National railways. Many small lakes, commonly of the linear type and with elongations east and west, occur among the forested rocky ridges near Jellicoe (Figure 1) and to the east and west along, or adjacent to, Sturgeon river. This stream has long stretches with gentle current between the falls and rapids. The drainage system provides excellent canoe routes (Figure 2), and the interruptions to travel (Figure 3) are remembered .as scenic features that were passed by portages with firm footing. West of Obonga lake, the streams flowing easterly to lake Nipigon may be followed through scenic canyons to a plateau of law relief characterized by extensive muskegs and shallow, brown-water lakes; and along small streams, where beaver dams have been destroyed, there are muck ponds where the usual alternatives of paddling or portaging can be dismissed in favour of the 'moosing' method of progress with the canoe (Figure 4).

Jan 1, 1935

By P. C. Benedict, J. A. Titcomb

"The following description of the geology of the Northern Empire mine is recorded by the senior author, but is based on the observations and complementary mapping of both authors.The Northern Empire mine is a mile east of Beardmore, and 100 miles northeast of Port Arthur, Thunder Bay district, Ontario.Production started in March, 1934, and terminated in September, 1941. The total number of tons milled was 425,866, from which 153,103 oz. gold was recovered. The lowest level from which ore was mined was the 1,900- foot, but considerable drifting was performed on the 2,075-foot and 800 feet on the 2,415-foot, the deepest level,The vein strikes about N.72°E. and has an average dip of80°S. In stoped sections the quartz averaged about 2 feet wide. On the 1,725-foot level it was drifted on continuously for more than 7,000 feet. In the mine as a whole, practically no commercial ore was found beyond points 1,400 feet west and 1,800 feet east of the shaft. Conspicuous wall-rock alteration extended throughout this section, but not much beyond these limits. There was some splitting of the vein and widening of the alteration halo on the lower levels. The average general colour of the quartz changes with depth .The vein is in 'Keewatin' lava flows, to which it is almost conformable. It lies only a short distance south from the 'Timiskaming-Keewatin' contact ( Fig. 2). This contact is marked by a black graphitic fault. So far as is known the fault is parallel, or nearly parallel, with the flows in strike, but dips at 72°S., which is 5° flatter than the average dip of the overturned flows. A post-vein, almost flat sheet of diabase about 550 feet thick cuts outthe vein from about the 650- to the 1,200-foot level ( Figs . 1 and 3). If it was intruded along a fault, the fault had only minor displacement. A strong alteration halo extends to 200 feet above and below the diabase. The vein was conspicuous but in large part it was below ore grade for 100 feet or more above and below the diabase.-"

Jan 1, 1954

By P. R. G. Brandão, E. E. Ferreira

The presence of metallic cations in solution will affect the aggregation or dispersion of the fine hematite particles, depending on the type of cation adsorption: either specific or non specific adsorption. In this work, the zeta potential measurements were carried out on a sample of pure hematite as a function of pH and metallic cations concentration (Ca2, Mg2+, Mn2+, K+, Na+ and Al3+). The objective of these studies was to clarify the effect of these metallic cations on the surface chemical properties of pure hematite. The cations K+ and Na+ adsorbed as non-specific species and caused only the reduction on the values of zeta potential (in terms of absolute value) over the entire range of pH values tested. For the Al3+ cation, in the acidic pH range it adsorbed as a specific species and increased the zeta potential values. The cations Ca2+, Mg2+ and Mn2+, adsorbed as a non specific species at pH levels less than 6.0 and caused the reduction of zeta potential due to the compression of the electrical double layer. However, for pH values greater than 6.0, these cations adsorbed as a specific species causing the zeta potential to increase and became more positive as the pH value increased (alkaline). This effect could be due to the adsorption of some hidroxy complex species of these cations, which contributed to the positive charge. The effect of metallic cations (Ca2+, Mg2+ and Al3+ concentration, at pH 4.0, 7.0 and 10, showed the following results: a) at pH 4.0, increasing the concentrations of Ca2+ and Mg2+ resulted in on a small reduction in the value of the zeta potential. At this pH, increasing the concentration of A131 cations caused the zeta potential to increase due to specific adsorption of a negatively charged Al3+ hydroxy complex b) at pH 7 and 10, increasing the concentrations of Ca2+ and Mg2+ caused the zeta potential to change its charge from negative to positive.

Jan 1, 2004

By A. Pawelczyk, D. Hreniak, E. Zych, W. Strek, K. Grabas, A. Ostrowski

"Mongolia is a country rich in rare earth resources. In the experiments carried out samples of the Mongolian ore were processed to obtain a lanthanide concentrate. The concentrate underwent hydrometallurgical processing. At the same time radioactive elements were removed. The lanthanides were obtained in the form of hydroxides that were further processed in order to get concentrated products. As a result cerium, lanthanum and neodymium-praseodymium concentrates were separated in the process. Also a concentrate of remaining elements: samarium, europium, gadolinium, terbium, dysprosium, holmium and erbium was obtained. INTRODUCTIONAccording to the assessment of the US Geological Survey, Mongolia possesses 16.77 % of the world total rare earth (RE) resources (Daly, 2011); that is the second largest RE reserve in the world, estimated to be 31 million tonnes in terms of rare earth oxides (REO). In the face of Chinese RE trade restrictions, Mongolia emerged as an important economical partner in mining and exploitation of these critical raw materials. This country is recognized as having more than five large RE deposits in the southern provinces. The most important are Lugeengol (Lugin Gol), Mushgia Khudag, Khotgor and Khalzan Buregtei (Eurasia, 2010). The Mongolian government has taken measures to facilitate western investments, nevertheless the country is economically dependent on China, the basic trading partner, particularly where exports are concerned.In the late 1970s Hydromet Kowary Enterprise, Poland, took up, along with the Wroclaw University of Technology, research and technological study on lanthanides recovery from raw materials of Vietnamese and Mongolian origin and from Indian monazite sands (Kowalczyk, 1990; Kowalczyk & Mazanek, 1987; 1990). For that purpose, a rare earth processing plant had been constructed with the capacity of about 10 t/year of hydroxide concentrate. The facility included several technological operations like grinding, flotation, hydroxide concentrate production in the hydrometallurgical processing, particular RE separation, and production of commercial products in form of CeO2, La2O3, Nd2O3, Pr2O3, and misch metal. Additionally work had been carried out in Kowary on the manufacture of yttrium and europium oxides of high purity, which were intended for color TV picture tube production in Poland."

Jan 1, 2012

By Roderick C. McDonald

Great Bear lake, the fourth largest body of water on this continent, comprises an area of approximately 12,000 square miles, and is set astride the Arctic circle, with a large portion of it witnessing both the Arctic winter night, and the Arctic summer day with its midnight sun. The very name itself, Great Bear, suggests an Arctic region. The seasonal contrasts at Great Bear lake are very marked by the cold and darkness of winter, and the warmth and brightness of summer. Signs of winter such as low clouds, snow, sleet, fog, and night frosts, generally appear the latter part of August, while ice forming on bays during the last two weeks in September ends boat travel on the lake about September 30th.Early in June the ice leaves the river mouths, during the last ten days of the month it disappears from small bays, and at some time during the last two weeks of July the main body of the lake becomes navigable. In 1916, the ice disappeared earlier than usual, and the lake was navigable on July 5th. Great Bear river generally breaks up about June 1st, but, on account of ice cliffs and floes, it is not navigable with safety until early in July. Even then, the traveller is confronted with the Charles rapids, but these might be overcome by a wagon or motor road, such as the one from Fitzgerald to Fort Smith: However, in 1931, Mr. A. W. Boland, Fort Norman, N.W.T., carried with scow and motorboat practically all freight between Fort Norman and LaBine point and Hunter bay, at the east end of the lake. During July and August, two types of clothing are required, for, although the days are mainly ones of warm sunshine, the nights are cloudy and cold. In the winter season, fur clothing is used exclusively. Considerable timber, mainly white spruce, suitable for fuel and building purposes, borders the lake and extends eastward to the Coppermine river. North of the lake, no timber is found except in the river valleys, but with oil and coal possibilities near Fort Norman, the fuel situation might be solved.

Jan 1, 1932

By Frank Ebbutt

Introduction The property of the Britannia Mining and Smelting Company, Limited, is situated on the east side of Howe sound, about six miles from its head. It is roughly thirty miles by water from Vancouver, one of the important ports of the Pacific and the industrial and financial centre of British Columbia. Howe sound is navigable for ocean-going vessels and Britannia Beach is a daily port of call for the commodious boats of the Union Steam-ship Company, sailing from Vancouver. Few mines are so ideally situated or have so many or varied natural advantages. Copper was first found on Britannia mountain in 1888, by Forbes, but it was not until 1898 that five claims were staked here by Oliver Furry, a trapper. It is from these claims that the major production during the past thirty years has come. In 1900 the Britannia Copper Syndicate was formed and development of the property was commenced. In 1903 the late Grant B. Schley obtained control, and through his efforts the Britannia Mining and Smelting Company was organized in 1908 as a subsidiary of the Howe Sound Company. Since that time, a persistent and progressive policy has been followed, which has resulted in a prolonged and profitable operation. The country in the immediate vicinity of the mine is marked by strong relief, with mountains rising abruptly from tide-water to elevations of 5,000 feet and more. Two broad transverse valleys deeply dissect the area. These are the valleys of Britannia creek and Furry creek. The region has under-gone prolonged and relatively recent glaciation. Over much of the surface there is deep overburden and dense vegetation. The geology of the mine and vicinity has been described in reports by S. J. Schofield (1), H. T. James (2), J. G. Barry, and others (3). The present writer is in accord with much of this literature on Britannia, but during recent years, extended observations made underground have shown that the 'quartz porphyry', or 'mine porphyry', of several of the earlier writers is not the host rock to the commercial mineralization; and he contends that the mineralization occurs in highly altered phases of a complex series of ruffs, flows, and pyroclastics and their autoclastic metamorphosed products.

Jan 1, 1935

By D. Tetsuka, H. Okamoto

The amount of impurities to be processed in a copper smelting process has increased for recent years because of an increase in the electronic scrap amount. It has been found that Sb and Ni effect on the operation of our copper electrorefining process. It is found that the current efficiency of the copper electrorefining tended to be decreased as the Ni concentration in the electrolyte increased. The passivation of the process seemed to be more related to SO4 concentration in the electrolyte rather than the Ni concentration in it. The current efficiency decreased when the Sb content in the anode was high. A high Sb content in the anode caused easy passivation by forming a gel-like film in the slime layer. We have developed a method to for see the anode passivation in a short time while generating a slime layer. We confirmed the tendency of passivation through the experiment of changing Pb content in anode. Passivation was easily occur with an increase in Pb content in the anode. The amount of slime increased as the Pb content in the anode increased. This suggests that passivation was facilitated because liquid diffusion near the anode was inhibited. INTRODUCTION The amount of impurities to be processed in copper smelting has been growing in recent years because the amount of electronic scrap has increased. Figure 1 shows that the contents of Sb and Ni in copper anodes have increased since 2007.High Sb and Ni contents in the copper anode decreased the current efficiency of the process and made the quality of copper cathode poor because of the anode passivation and the formation of floating slime in the electrolyte during electrorefining. If these influences of impurities are suppressed, it would be possible to make copper electro-refining current density higher and to process much amount of electronic scrap. We examined the components of our copper electro-refining process like anode composition, slime properties and electrolyte composition, and investigated the mechanism by which Sb and Ni affect passivation and current efficiency. When examining the influence of Ni, we noticed that the SO4 important. The effect of SO42 – was also discussed

Jan 1, 2019