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By Malcolm R. Gent

"The presence in Saskatchewan of sixteen kimberlite pipes of probable late Albian age has been reported. An abundance of aeromagnetic anomalies possibly attributable to kimberlite pipes have been identified and it is anticipated that industry has acquired reasonable proof of the presence of more than seventy k imberlite pipes in Saskatchewan. Historical reports of diamonds, the discovery of kimberlite pipes and these aeromagnetic anomalies indicate the Phanerozoic Basin and some parts of the exposed Shield in Saskatchewan have an excellent potential f or the occurrence of economically exploitable diamond deposits. The presence of some igneous minerals found in some salt solution breccias also indicates the probable occurrence of extensive diatreme activity during the Devonian.A Laramide Orogeny-induced crustal hinging or arching of the eastern margin of the Phanerozoic Basin and probably dextral wrenching-induced arching and faulting within the basin are proposed as major factors in the emplacement of Cretaceous or younger kimberlites. Zones of crustal weakness between subcratonic Archean blocks and internal faults are also thought to be significant controlling factors in the location of kimberlites in Saskatchewan.Mapped aeromagnetic anomalies interpreted as being possibly due to kimberlite pipes generally tend to be concentrated in, areas underlain by a basement of or with components of Archean age. Within Saskatchewan, these anomalies occur within the probable Trans-Hudson Orogen zone; the Rae-Hearn Craton margin; and the northeast flank of the Elkpoint Basin. Recognized areas of potential f or kimberlite emplacement are the Phanerozoic basin margin, the western limit of the Superior Province adjoining the Churchill Province, and a swath approximately 150m wide along the northeast-southwest trending Shaunavon linear and other areas of inner basin arching."

Jan 1, 1992

By M. P. Amsden

"Ecstall Mining is a wholly-owned subsidiary of Texas Gulf Sulphur at Timmins, Ontario. The mill tonnage is 10,000 tons per day of two different ores, a copper zinc ore and a silver lead zinc ore, producing about 2400 tons of concentrates per day. These are as a copper concentrate, a high silver zinc concentrate, a low silver zinc concentrate and a silver-lead concentrate. For flotation recovery a very fine grind is required, about 80% minus 325 mesh and the concentrates produced are 40% minus 10 microns.The thickened concentrates are pumped to the filter floor for filtering and drying. The filtering and drying section is separated from the flotation section by a wall and is controlled from a dryer control room by one operator.Two operating panels are located in this control room. One contains stop-start controls for the thickeners, filter motors and vacuum pump motors, and stop-start controls for dryer feed conveyors and dryer product conveyors to concentrate load-out bins, as well as ammeters for conveyor drive motors. Dryer throughput is regulated by Merrick Type L weightometers located on the dryer discharge conveyors and recorded on tons per hour strip charts.The second panel contains the temperature strip charts, furnace drive ammeters, scrubber and exhaust gas controls, burner controls and panel alarms for the four dryers.Filtered concentrates are dried in Nichols-Herreshoff, multiple hearth, dryers consisting of nine hearths (zinc) and seven hearths (copper and lead). There are two dryers for handling zinc concentrates and one each for copper and lead concentrates. The dryers are heated by burning natural gas. Each zinc dryer handles 1,000 t.p.d. and the copper and lead dryers 750 t.p.d. each.Multiple hearth dryers are unusual in the base metal mining industry and the reasons for selecting them in preference to rotary dryers are as follows:1) The concentrates could only be filtered to 15 to 17 percent moisture. These sloppy filter cakes would be extremely difficult to handle in rotary dryers."

Jan 1, 1972

By R. Gatzweiler

The Key Lake nickel-uranium deposits are situated within the Wollaston domain of the Churchill structural province. The host rocks of the two orebodies are of Aphebian and Helikian age. The orebodies occur mainly within a 5.2-km-Iong, northeast-trending zone which coincides with the intersection of the sub-Athabasca unconformity and a reverse fault striking east-northeast. The principal controls of mineralization are structural and lithostratigraphic (i.e., post-Athabasca faults, the sub-Athabasca unconformity and graphitic metapelites in the lower Aphebian, close to the Aphebian/Archean unconformity). Grades of up to 35% U3O8 and 20% Ni are recorded over intervals of up to 2 m. Some hypogene zonation exists and the nickel mineralization tends to underlie the high-grade uranium ore. The ore minerals include pitchblende, a-U307, coffinite, gersdorffite, millerite, niccolite, bravoite, zoisite, sericite, chlorite and kaolinite. The kaolinite is a post-ore, supergene alteration product. Chemical studies of the sub-Athabasca paleo weathering profile sho w that regolithization is characterized by depletion in Si02 and K20 and concomitant enrichment in Al203 and perhaps MgO. In the paleoweathering profile the ferromagnes ian minerals are chloritized, the Ksfeldspars sericitized and the plagioclase saussuritized. Preliminary geochronologic data from the ores reveal U/Pb ages of -1228 my, - 960 my and 89 my, and Rb /Sr data indicate basement ages of -1850 my and - 1372 my. Aphebian pelitic protoliths, carrying U and Ni, may have released some metals during post-Hudsonian weathering, and minor concentration in structural and geochemical traps may have taken place prior to the deposition of the Athabasca strata. However, it is felt that the bulk ofthe ore-grade mineralization wasgenerated after the deposition of the Athabasca formation and after faulting, probably during a major regional thermal/ intrusive episode of Grenvillian age. Several episodes of remobilization took place between 1228and 89 my ago.

Jan 1, 1979

By Don Peel, Jeremy Richards

Abstract - Aggregates (sand, gravel, and crushed stone) are low unit-cost products extracted in very large volumes for the construction of buildings, roads, and other infrastructure essential to modern society. Because of their low unit value, transportation costs are a key factor in resource economics, and deposits are commonly developed close to market (i.e., close to towns and cities, or along low-cost transportation corridors). This proximity results in potential conflict with residents over land use, disturbance, and pollution. Management of aggregate resources in Alberta is examined in the light of resource geology and distribution, and governance. A case history of development of the Calahoo-Villeneuve deposit is described, and the conflicts between residents and developers that led to establishment of an Area Structure Plan (ASP) are explored. The plan sets limits to, but at the same time safeguards, resource extraction, and defines terms for compensation to residents through a voluntary levy on production (Community Enhancement Fund). This fund is used to support community activities and to pay for a groundwater monitoring program. The ASP is examined within the context of the "Seven Questions to Sustainability" as set out by Mining,Minerals and Sustainable Development-North America (2002). It is concluded that the ASP, for the most part, provides a good model for conflict resolution and sustainable resource development, which could usefully be applied in other jurisdictions. The ASP was developed at a municipal level, and adoption at a provincial level would aid sustainable development of aggregate resources across the province.

Jan 1, 2003

By G. Harper

The Sustut Copper deposit, 230 miles northwest of Prince George, B.C., was discovered in August of 1971. Subsequent exploration has included 56,417 feet of surface diamond drilling in 139 holes. The deposit occurs in gently dipping volcanic rocks of the Upper Triassic Takla Group, which outcrops as rugged mountains. The general Mesozoic sequence comprises some 20,000 feet of green and red basaltic to andesitic rocks. The Lower Formation is characterized by subaqueous basalt, andesite and augite porphyry flows with interbedded breccias. They were rapidly deposited in tectonic depressions of limited extent and steep gradients. Fades changes are abundant. The Middle Formation consists of volcaniclastic rocks made up of fragments from the underlying formation. Two cycles are discernible, both with basal turbiditic, tuf-faceous sandstone and shale units overlain by massive, volcanic conglomerates exhibiting graded and cross bedding. A broader, shallower-water basin is indicated. The top of the uppermost unit was subaerially deposited. The Upper Formation is a variable sequence of volcanic sedimentary rocks. Detritus was supplied from a wide source area and included multiple reworked fragments of the lower formations and material from other rock groups known in the region. Zeolite fades metamorphism is recognized throughout the entire sequence. Epidote is particularly abundant in the Middle Formation, demonstrating the results of metasomatism. The mineralized zone is approximately concordant with the strata over 100-200 feet of the Middle Formation succession. It lies just below the zone of transition from subaqueous to subaerial deposition in the top unit. Hematite, chalcocite, pyrite, bornite, chalcopyrite and native copper are disseminated throughout all sizes of lithic fragments and matrix. Concentration into the specific zone is believed, to be due to upward leaching of copper during low-grade metamorphic and metasomitic reaction. Precipitation occurred in the zone of hydration characterized by prehnite-pumpellyite below the oxidized subaerial rocks.

Jan 1, 1977

By Philippe Portella

Current Ownership : AREVA NC-France & affiliates (63.4%), ONAREM-Niger (36.6%)Related Mines : Ariège, Artois, Arlette(initial Somaïrlease) and Tamou, Taza, Takriza, Tamgak(SMTT lease)Mining Method : Open Pits Reserves : about 14 000 tU Average grade : 0.3 % UEnvironmental Management : Certified ISO 14001 since November 2002Key figures :2003 output : 1126 tU number of employees at year end : 565 Current Ownership : AREVA NC-France & affiliates (34%), ONAREM-Niger (31%), OURD-Japan (25%), ENUSA-Spain (10%) Related Mines : the Akouta mine provides access to several adjacent orebodies(Akola, Akouta, and coming Afasto with Ebba North / South)Mining Method : Underground ?mainly room & pillars Reserves : about 29 000 tU Average grade : 0.40 to 0.50 % U3O8Environmental Management : Certified ISO 14001 since January 2003Key figures :2003 output : 2017 tU number of employees at year end: 1070

May 1, 2006

By R. M. Bustin

"Extensive deposits of tectonically sheared coal of the Mist Mountain Formation occur in the south eastern Canadian Cordillera. The quality of the coal varies markedly; it is commonly partially oxidized and poor washability characteristics.Oxidation of the sheared coal has been promoted by its fine grain-size and by fractures in adjacent rocks which have facilitated penetration of atmospheric oxygen and circulation of oxygenated waters. Oxidation has resulted in a loss of coking power, a decrease in vitrinite reflectance, and an Increase In oxygen and decrease in carbon content.The relatively low clean coal yields of the sheared coal are primarily the result of the greater volume of mineral matter present, which in turn reflects both the greater susceptibility to shearing of coal with abundant rock partings and the shearing and dissemination throughout the coal of formerly discrete rock partings. The high ash content of some sheared coal seams may be artificial, resulting from the difficulty in distinguishing and separating sheared roof rock and floor strata from the coal seam during mining. There is little variation between the quality of the washed sheared and unsheared coal, with the exception of the somewhat higher ash content of the clean sheared coal compared to clean unsheared coal. This poorer separation of the ash from the organic fraction of the sheared coal is considered to be a product of the large amount of fines present as well as the local formation of aggregates of organic material and ash resulting from plastic flowage of the vitrite and clarite during shearing.IntroductionIn the southeastern Canadian Cordillera, coal seams of the Lower Cretaceous Mist Mountain Formation (Gibson, 1979 were in part sheared and comminuted during Late Cretaceous and Tertiary tectonism . Extensive deposits of sheared coal exist, and even in areas of mild deformation the coal may be locally sheared (Bustin, 1979). The quality of the sheared coal varies notably; it is commonly oxidized even far from the present weathering horizon, and locally has a disproportionately large amount of ash and poor washability characteristics even far from the present weathering horizon and locally has a disproportionately large amount of ash and poor washability characteristics."

Jan 1, 1982

By K. Wongpreedee

Recovery and recrystallization of Au wire can degrade strength and alter conductivity properties during exposure to elevated temperature. Au Deformation Processed Metal Metal Composites (Au DMMC's) are being developed for electronic applications requiring high conductivity and high strength. This paper discusses the relationships between microstructure, strength, and resistivity of Au DMMC's. It also presents the results of a recent study on the elevated temperature stability of Au DMMC's of several compositions. Au-7 vol %Ag, Au-14 vol %Ag, and Au-vol 7%Pt DMMC samples were prepared by a powder metallurgy technique. All specimens were processed into wire by extrusion, swaging, and drawing. The smallest final diameter of these wires was 120 ?m. Thermal stability was analyzed by electrical resistivity measurements to determine the relation between transformation rates and time at elevated temperature. The extensive deformation used to produce these composites reshaped the initially equi-axed powder into filaments that are 30 to 100 nm in diameter and 16 to 180 mm in length. The small filament diameter confers high strength on the composite. The high conductivity can be explained by electrons flowing parallel to the filamentary microstructure aligned with the wire axis. Using the Avrami and Arrhenius equation relationships, it is possible to predict the times and temperatures needed to achieve various degrees of homogenization. The Au DMMC's were found to have good thermal stability compared to conventional coldworked Au interconnection wires. Although these composites will revert to solid solutions if exposed to high temperatures for prolonged time periods, their relative stability is sufficient to allow them to maintain their twophase microstructure during the anticipated lifetime temperature profiles of many products.

Oct 1, 2003

By Robert J-M Ethier

"Sequential blasting has been introduced at Mines Gaspe to reduce the harmful effects associated with the instantaneously primed blasting method. Three stages of modifications had been tried to improve this method: trials of a rectangular pattern instead of the square one, trials of lengthened hole collars at the perimeter of the blast and trials of increased inter-row delay intervals from 35 to 50 ms. Results showed that improvements to the instantaneously primed blasting method were limited by the probability of increasing the number of bootlegs.Doing these modifications allowed the definition of a general approach to improvements before the sequential blasting method was introduced. This general approach included: planning of the mining sequence, following up on the drilling, loading and tying-in of each blast, compiling and evaluating blast results, comparing results from one bench to the other and moving along with one change at a time. This approach has permitted the successful introduction of the sequential blasting method in two steps: trials of blast by rows of delayed holes and trials of hole-by-hole blasts. The optimum result has been analyzed by high-speed camera and by computer blast simulations, The actual optimum sequential blast is obtained with a CORDLINE priming system using period 15, permitted in a large drilling pattern, with an intersequences delay interval of 230 ms and an inner-sequences delay interval of 50 ms.While these modifications were being introduced, a careful study of the drilling and blasting costs was made, which showed a sharp reduction of drilling cost per tonne. Even though there was an increased use of packaged slurry the blasting cost per tonne also dropped. The reduction in cost per tonne was explained by the fact that the average energy factor was maintained while the blasting pattern was expanded.The sequential blasting method, successfully introduced at Mines Gaspe, permits blasts of better quality, reduces the drilling requirements by more than 30% and helps to achieve improved productivity while minimizing costs."

Jan 1, 1984

By Steven Dempsey

Overview What is Tubbing? A look at Cigar Lake Tubbing Design The Tubbing Installation Backwall Grouting

May 1, 2013

By Rui Wang, Engang Wang, En Jiang, Anyuan Deng, Xingwu Zhang, Fei Wang

In this paper, the rectangular strands of Incoloy 800 superalloy were fabricated with a pilot vertical continuous caster in Northeastern University, China. In the processing, an electromagnetic stirring (EMS) is applied on the secondary cooling zone to control the solidifying structure and segregation of elements in the strands. The solidification structure of Incoloy 800 superalloy strands were investigated at different electric parameters and casting parameters. The research results show that the EMS can effectively restrain the dendrite growth and increase the ratio of equiaxed grains in Incoloy 800 superalloy strands as applied a suitable electric parameters and cooling condition in the process of continuous casting. The evolution of dendrite crystallization in Incoloy 800 alloy strands from the surface to its center during the solidifying process was investigated with and without EMS.

Jan 1, 2014

By F. Ford, J. Dong

"Laboratory and miniplant testwork was carried out to reject uranium from an Iron Oxide Copper Gold (IOCG) deposit that contains an average of 60-70 ppm uranium with high variability. The dominate copper bearing mineral is chalcopyrite with minor bornite and trace covellite. The main gangue minerals are iron-rich chlorite, quartz and magnetite. The main uranium-containing mineral is uraninite (UO2). Downstream processes require the maximum uranium level of no more than 80 ppm in final copper concentrate.Mineralogical examination reveals that uraninite particles are finely disseminated with grain size of less than a few microns in the deposit requiring fine regrind in order to liberate uraninite from chalcopyrite particles. A lab flowsheet was developed to include ultrafine regrind of the rougher concentrate to the particle size of 80% passing 11-13 µm with up to four stages of recleaning in flotation columns. Finer regrind to 80% passing 5-6 µm may continue to improve liberation but does not decrease uranium level in the final concentrate. In each of the successive recleaning stages by flotation column after fine regrind, uraninite is rejected into the column tailings, with the final copper gold concentrate containing less than 70 ppm uranium from a feed containing 83 ppm uranium. The conceptual flowsheet was further tested in an integrated, continuous miniplant showing average 94% copper recovery with average 74 ppm uranium. The uraninite particles that report to the final concentrate are either locked with chalcopyrite or entrained as liberated particles of less than 5 µm in size."

Jan 1, 2016

By P. W. Percival, J. J. Janssens

"Whitehorse Copper is a 2600-ton-per-day underground copper mine located within the city limits of Whitehorse, Yukon . In early 1978, due to increasingly difficult ground conditions. it was decided to investigate the conversion from longhole open stoping to vertical crater retreat mining. On-site crater testing by C-I-L demonstrated the feasibility of V.C.R. mining at Whitehorse Copper.After some investigation. a down-the-hole drilling rig was chosen and drilling began in November /978. Blasting began in June /979. and to September 1980 approximately one million tons of ore had been blasted. In-field changes to both drilling and blasting techniques have been implemented. Some of these changes were dictated by problems encountered; others were made to improve efficiencies.To date. V.C.R. mining has proven successful from a drilling and blasting aspect.IntroductionWhitehorse Copper Mines Ltd ., a division of Hudson Bay Mining and Smelting Co., Limited , is a 2600-Lp.d. underground copper mine. The plant site is located I mile west of the Alaska Highway, and approximately 7 miles south of Whitehorse city center. Production is from the Little Chief orebody, and total output is from vertical crater retreat stopes.The Little Chief and Middle Chief orebodies at Whitehorse Copper had original reserves in excess of 6 million tons, most of which graded 2.00/0 copper or higher . The orebodies are typical skarn deposits that have developed along the contact between an intrusive diorite and a limestone-quartzite flank pendant. The limestone has been metasomatized to form a calcium-magnesium skarn which, along the limestone / quartzite contact, has locally further developed into a mineralized magnetite-serpentine skarn. The principal copper minerals are bornite and chalcopyrite, with minor chalcocite and valleriite. Skarn gangue minerals are serpentine, diopside, garnet, epidote, calcite and wollastonite. Appreciable values in gold with some silver are present and recovered as well."

Jan 1, 1981

By R. Bonnar, R. J. McH. Clark

"The Cheminis gold mineralization zone is approximately 6.5 km west of the Kerr Addison Mine along the Larder Lake Shear Zone, in the southern part of the Abitibi Greenstone Belt. The zone is very similar in appearance to the flow ore at the Kerr Addison Mine and occurs at the same stratigraphic position. Drilling has demonstrated that the gold mineralization at Cheminis persists to a depth of over 3000 ft .The mineralization is hosted by a pyritic, tuffaceous sediment which occurs within a sequence of volcanics and sediments which have been pervasively carbonatized. The gold is largely enclosed within pyrite grains and the amount of gold in the layers of pyrite increases in the layers closest to a graphitic f ault zone.It is suggested that the gold mineralization may be primarily related to the syngenetic sulphide concentrations formed during fumarolic activity on the seafloor along the Larder Lake Shear Zone. At a later stage a hydrothermal event associated with alkalic volcanism may have resulted in regional carbonatization and further concentration of the gold in the vicinity of fault zones."

Jan 1, 1987

By Greg Johnson

Maintenance needs information about assets to optimize availability and production needs information about performance and consumption to maximize output. In considering both these needs together as, ?Asset Optimization?, the information systems that support them are critical. The theory of Asset Optimization derives from the Lean Manufacturing concepts developed by Toyota, but some changes are required to apply this to mining operations. In particular, mining operations require automated systems due to their geographic spread and they need a strong emphasis on capturing under-performance losses as well as delays and stoppages in production. Leading metal miners and coal miners alike have applied these systems to good effect in the last 10 years. The concepts developed initially in minerals processing plants are now being applied to the mines themsleves as well as the mining logistics chain. Production increases of 5?10% are achievable with the right implementation and consideration of the some key lessons learnt in the last 10 years. Putting these lessons into action is one key step in the goal of optimizing asset performance and thus utilizing the resource at lowest cost.

Aug 1, 2013

By Jerry Z. Lu

Belt conveyor design involves the evaluation of belt tensions, drive selection, pulley configuration and other technical issues. The conveyor belt tensions vary with conveyor layout, drive pulley configuration, belt selection, and idler selection. The decisions for the belt conveyor construction always take all technical, commercial and maintenance issues into consideration. A good conveyor design shall provide required operational features and at the same time be cost effective. The common issues for an engineer to face during belt conveyor design include: (1) Conveyor drive selection ? drive with fluid couplings or variable frequency drives; (2) Drive system configurations - single pulley large drives or dual pulley smaller drives, if intermediate tripper booster drives shall be applied, what power ratio should be adopted for a multi-drive conveyor; (3) Gear reducers ? shaft mount drives, right angle gear reducers or parallel gear reducers; (4) Drive pulley lagging - ceramic lagging or rubber lagging; If ceramic lagging, what type should be used. (5) Conveyor speed variation ? If conveyors run at variable speeds, faster speed/lower percentage loading or slower speed/higher percentage loading. In many cases the decision maker find themselves in a dilemma ? technical benefits vs. financial benefits, capital cost vs. operational cost, and capital and operational cost vs. maintenance effort. Although many conveyor design topics above have been discussed in numerous technical papers and design reference books, management executives and inexperienced engineers may be confused and feel lost. The consultation of people around them may lead to different opinions since experiences tend to vary, making the decision making process complicated. The purpose of this paper is to simplify these complicated issues and provide useful guidelines for belt conveyor design. This paper focuses more on providing simple and practical answers and solutions instead of discussing each topic academically and theoretically in depth.

Nov 1, 2011

By P. G. Keohane, J. S. Drake

"Cominco's Polaris Mine is a lead-zinc underground operation that began commercial production in early 1982. The mine site is located on Little Cornwallis Island in the Canadian Arctic at a latitude of 75°23'N and at a longitude of 96°55'W. The nearest settlement, Resolute Bay, some 100 kilometres southeasterly from the mine, is accessed from the mine by light aircraft. The mine site can be accessed by sea during the six-week ice-free period each year. During this time all major operating supplies are brought to the mine and the lead and zinc concentrate products are shipped out to market.GeologyThe Polaris orebody lies near the top of the Thumb Mountain Formation of Ordovician age. This formation is a relatively homogeneous section of thin to medium bedded limestones which are brecciated and dolomitized in the area around the orebody. The deposit is described as a Mississippi Valley-type orebody. Ore minerals are sphalerite and galena with the waste being predominantly dolomite with calcite and marcasite. The ore is quite porous with voids being generally filled with ice as the mineralized zone lies entirely within permafrost. Reserves consist of about twenty million tonnes of ore grading 3.8% Pb and 14.3% Zn with a further three million tonnes of inferred ore at a slightly lower grade.The orebody strikes in a north-south direction with the hangingwall dipping at about twenty degrees to the east. It is generally conformable with the stratigraphy. The footwall in the western portion of the orebody, the Panhandle, lies about 10 to 30 metres below the hangingwall. To the east the footwall drops sharply, creating an orebody height of up to 110 metres in what is referred to as the Keel Zone. The Panhandle Zone has typically 80 - 110 metres of cover above the hangingwall , About 25% of the reserves are in the Panhandle Zone, the remainder being in the Keel Zone. Figure I illustrates a plan view of the orebody relative to other surface facilities on the property and Figure 2 illustrates a simplified section through the Panhandle and Keel Zones."

Jan 1, 1985

By H. K. Olsen, B. Thomassen, H. K. Schønwandt, L. Grahl-Madsen, H. Stendal

Abstract-The central part of the early Proterozoic Ketilidian orogen in South Greenland consists of an I-type granitoid batholith transected by four regional NE-SW-trending shear zones. The batholith was probably emplaced during subduction, from the south toward the Archaean craton in the north, in a sinistral transpressional system. A regional sediment sampling program covering 5000 km2 shows a close connection between a gold-mineralized trend and one of the major shear zones within the epizonal facies of the batholith. The gold mineralization is not directly related to the major shear zones, but occurs in quartz-veined and silicified second-order structures. High-grade (up to 114 ppm Au over 6 m) low-tonnage mineralization is found within these second-order structures cutting both amphibolites and granitoids. The mineralization is characterized by negligible or small alteration halos. Gold is associated with various element combinations of enhanced As-Bi-W- Cu, which indicate that the mineralization is mesothermal in origin.

Jan 1, 1995

By H. K. Olsen, B. Thomassen, H. K. Schønwandt, L. Grahl-Madsen, H. Stendal

The central part of the early Proterozoic Ketilidian orogen in South Greenland consists of an I-type granitoid batholith transected by four regional NE-SW-trending shear zones. Thebatholith was probably emplaced during subduction, from the south toward the Archaean craton in the north, in a sinistral transpressional system. A regional sediment sampling program covering5000km2shows a close connection between a gold-mineralized trend and one of the major shearzones within the epizonal facies of the batholith. The gold mineralization is not directly related to the major shear zones, but occurs in quartz-veined and silicified second-order structures. High-grade(up to 114 ppm Au over 6 m) low-tonnage mineralization is found within these second-order structures cutting both amphibolites and granitoids. The mineralization is characterized by negligible or small alteration halos. Gold is associated with various element combinations of enhanced As-Bi-W-Cu, which indicate that the mineralization is mesothermal in origin.

Jan 1, 1995

By Abdurrahman Tosun

It is very important for after blasting processes that muck pile fragmentation is predicted and controlled during blasting. Therefore, a significant research effort has been devoted to the development of mathematical equations that predict the value of average muck pile fragmentation. The specific charge parameter used in all of these equations is determined as the ratio of the total mass of explosives used to break a volume of rock. The length of blast surface and the row number of the blasthole are ignored in the calculation of the specific charge. However, in a blasting operation, blasthole geometry may result in additional material being impacted by a blasthole. This is due to effect shares of in both end sides of blastholes and the back region of blasting surface. In this study, a total of 14 blast tests, 8 at the first quarry and 6 at the second quarry of the Bati Anadolu (Western Anatolia) Cement Factory, were performed. In each study area blast tests were designed in the same direction continuously to provide stable structural properties of the rock. Therefore muck pile fragmentation depended on only specific charge values for each blast tests. Specific charge values were calculated according to both an average blasthole and also the total volume of material occurred as a result of blasting for each blast tests. During loading until the end of blasted material the front, the back, the arm off and the bucket off pump hydraulic pressure values occurred in hydraulic pistons of the loader were determined with a lot of data received for each blast tests. After that the relationships between specific charges values obtained according to two different methods and hydraulic pressure values of the loader were established with two correlations. The relationships between specific charges values obtained according to the total volume of material occurred as a result of blasting and hydraulic pressure values of the loader occurred as the best results especially the blasting operations that have the total length of blasting surfaces are short.

Aug 1, 2013