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By S. Manning, W. Morris

Mineral exploration assessment file information has long been considered a useful resource for developing mineral exploration strategies, and one of the most common data sets fled in assessment reports is ground magnetic surveys. The new Earth Resources and Land Information System database (ERLIS) now provides a method for rapidly accessing all references to a specific area through a series of raster images. The ERLIS provides access to the Assessment File Research Imaging (AFRI) database which comprises geo-science mineral exploration assessment file data, Mineral Deposits Inventory (MDI), together with provincial aeromagnetic data from the Ontario Ministry of Northern Development and Mines(MNDM). Conversion of the raster images of ground geophysical data to vector data files together with the concatenation of grids from adjacent claims provides a method for constructing high resolution magnetic regional images. The value of this resource is demonstrated through the construction of a single composite magnetic image derived from eight assessment file grids for an area south of Kirkland Lake, Ontario, within Pacaud and Catharine Townships. The composite grid of magnetic data provides a map with resolution that is not achieved by currently available Ontario Geological Survey airborne data sets. Details contained within the new high resolution image, permit the differentiation of lithologies and their boundaries, fault orientations and the location of alteration zones with magnetic response.

Jan 1, 1997

By Gordon L. Draeseke

"Before getting into more specific aspects of my talk today I should put in one disclaimer - one week in Mainland China and one day with Premier Kosygin does not make me an expert on Sino-Soviet affairs nor on Canadian-Chinese relations. Perhaps though there is a message in the fact that one meeting took place in relative openness in China and the other was at least partly in a bullet-proof limousine in Canada. I thought it might be interesting and appropriate to explain something of the forest industry to you who are engaged in the mining industry. Our industry, like yours, is based on a natural resource and the basic activity that we engage in is the extraction and conversion of that resource into saleable materials. However, the fundamental difference between our industries is that our resource is on top of the ground - easily visible and easily measurable, whereas yours is under the ground - difficult to find and, having been found, expensive to measure. A second difference is that ours is renewable while yours is extractive, and you must keep finding more to keep up reserves."

Jan 1, 1971

By L. S. Brooks

TIMBER HANDLING presents a problem for any mine where appreciable amounts are used. This problem is accentuated where the shaft compartments are too small to allow a loaded timber truck to be lowered in the mine cage. When Normetal Mining Corporation, Limited, found it necessary to resort to square-set mining it faced this problem of getting large quantities of timber down a shaft that was also required for hoisting ore. A 'timber car' that could be suspended under the cage was developed to overcome this difficulty. Production started at the Normetal mine in 1937, at the rate of 250 tons per day. In 1938 a winze, known as No. 3 shaft, was sunk from the 800-foot level ?to the 1,385-foot level. This was later raised to surface and then deepened to 3,275 feet in three stages and became the main production shaft. The portion of the mine below the 3,070-foot level is serviced by a winze, locally referred to as No. 4 shaft, which has been developed for stoping down to the 3,990-foot level and which has been deepened to the 5,365-foot level. No. 3 shaft has two hoisting compartments, each 4 ft. 6 in. by 5 ft. 0 in. inside the timbers, through which the ?ore must be hoisted and timber and supplies lowered.

Jan 1, 1956

By Xian Jian Guo, Lei Li, Hua Wang

The distribution and behavior of As, Pb and Zn elements in the copper smelting process were investigated using thermodynamics. The differences between thermodynamics evaluation and practical smelting processes were analyzed. The main factors affecting the distribution of the elements are oxygen enrichment in blowing, copper matte grade and smelting temperature. In general, the distribution ratio of As, Pb and Zn to off gas increases with the smelting temperature and decreases with oxygen enrichment in blowing. Meanwhile, their distributions in matte decreases and that in slag increases with the increase of copper matte grade. There is some gap in distributions between thermodynamics evaluation and practical smelting processes. INTRODUCTION The copper concentrates usually contain a number of minor elements, the control of which in copper smelting processes is often a key to the quality of the anode copper produced and may also have a bearing on the overall economics of the process (Yang et al., 2017). Knowledge of the thermodynamic properties of the minor elements in slag is very important in the control of the slagging reactions (Takeda Y, Ishiwata & Yazawa, 2007). In addition, the environmental contamination caused by the minor elements associated with copper-bearing ores, such as As, Pb and Zn, has become more and more important (Wang, 2004). Arsenic, lead and antimony, which are all carcinogenic metalloid elements, are usually contained in iron-rich wastes, and theirs emissions are considered to be one of the foremost environmental concerns (Wang, 2004). It is important to elucidate the elements distribution of them in the reducing-matte smelting process. The distributions of As, Pb and Zn elements in the copper smelting process are dependent on many factors, including the temperature, raw material composition, reduction atmosphere, concentration level, and slag chemistry etc. (Chen L Z, Xu X, 2016). Generally, these minor elements mainly distribute in phases of gas, copper matte and slag in the smelting process (Shu, Wang, & Qu, 2016). The arsenic exists mainly in the form of sulfo-arsenides in the copper concentrate, and it will decompose and be oxidized in the smelting process (Chen & Lu, 2016). Part of the products, including AsS, AsO, As2 and As2O3, evaporates into the gaseous state, and some other part enters into slag phase in the form of As2O3 and As2O5 (Wang, Guo, & Tian, 2017). Meanwhile, the As2O3 in the slag phase can also be reduced to metallic As and combine with Cu, S, Fe forming Cu3As2, As2S3 and Fe3As2, and then enter into copper matte. During the copper smelting process, about 50% of zinc enters into slag phase in the form of ZnO and 45% exists in the copper matte in the form of ZnS. Little volatizes into the gas phase. Most lead exists in forms of PbS and PbO in the copper concentrate, and it is mainly distributed in copper matte in the smelting process (Zheng & Lin, 2015).

Jan 1, 2019

By E. Best

In 2003, Phelps Dodge Mining Company decided to pursue the design and construction of a Central Analytical Laboratory to provide chemical analyses for their Arizona and New Mexico operations. This centralized approach was selected in place of refurbishing six (6) older laboratories that operated at the various Phelps Dodge sites, and which would not have permitted full automation and use of robotics. The new lab was designed by the Process Technology Center (PTC) Material Characterization Group in cooperation with IMP Group. The Central Analytical Service Center (CASC) encompasses fully automated sample preparation of blast holes and geological samples weighing up to 15 kg/sample. The CASC also includes the first "wet chemistry module" worldwide to be operated by robotics systems to perform Total Cu, Acid Soluble Cu, and Quick Leach Tests (QLT), and a fully automated lab for electrowon copper cathode. The new lab also offers flexibility for handling specialty samples and analyses by either semi-automated or manual mode. Data handling and transfer is accomplished using the commercially available StarLIMS system. Commissioning was accomplished within five (5) months of startup during which the CASC also handled 86% of a full production load. The 24/7 lab operation has already exceeded its design capacity, has achieved considerable savings in operating cost, reduced sample preparation errors, and significantly increased analytical quality.

Jan 1, 2007

By M. J. Nicol

The leaching of gold with thiosulfate solutions in the absence of ammonia and copper ions was investigated using electrochemical and kinetic methods. In sodium thiosulfate solutions, the electrochemical oxidation of gold was hindered and the leaching rate using pure oxygen as the oxidant was very slow. It was found that the addition of a small amount of thiourea or formamidine disulfide to the thiosulfate solution greatly enhanced the oxidation of gold. However, the enhancement to the overall dissolution of gold using dissolved oxygen as the oxidant was limited. This was attributed to the fact that the oxygen reduction process was unaffected by the additives and remained slow, which limited further improvement to the overall kinetics. An alternative oxidant, the ferric EDTA complex having a reduction potential of approximately 0.12 V, was found to be promising. The cathodic reduction of ferric EDTA was fast and reversible at neutral pH. While the ferric EDTA complex was effective in oxidizing gold, it did not appear to significantly oxidize thiosulfate. A thiosulfate solution containing thiourea and ferric EDTA has been shown to quickly dissolve gold in the form of a powder as well as from gold ores. In the leaching with the ores high gold recoveries of above 90% was achieved with the best performance obtained in neutral solutions (pH 6-7).

Jan 1, 2005

By X. Cao, X. -G. Chen, K. Liu

Due to the detrimental effect of platelet iron-rich intermetallics on mechanical properties (particularly ductility) in cast alloys, it has been essential to transform these phases into Chinese script morphology. In the present work, the effects of Mn and/or Si addition and cooling rate on the phase transformation of the iron-rich intermetallics in 206 cast alloys with different Fe contents ranging from 0.15 % to 0.5 % were systematically investigated. The results obtained showed that platelet ß-Fe and Al3(FeMn), Chinese script a-Fe, Alm(FeMn) and Al6(FeMn) can be observed in the 206 cast alloys, depending on the Fe, Mn and Si contents as well as the cooling rate. It was found that the addition of either Mn or Si favors the formation of Chinese script iron-rich intermetallics but inhibits the precipitation of the platelet phases. In addition, the combined addition of both Mn and Si has a synergistic effect on the phase transformation. Furthermore, there exists a critical cooling rate to effectively suppress the formation of platelet iron-rich intermetallics for a given alloy. The threshold cooling rate decreases with increasing Fe, Mn and Si contents. Casting process maps are established to correlate the intermetallics precipitated with alloy chemistry and cooling rate for 206 cast alloys containing various Fe levels.

Jan 1, 2014

By G. Avramovic-Cingara, H. J. McQueen

The microstructure of commercially pure aluminum was investigated by using polarized optical microscopy (POM), orientation imaging microscopy (OIM), and transmission electron microscopy (TEM) techniques. Specimens were deformed in torsion at 400°C and equivalent strain rate of 0.1 s-1, to various strains of 0.2, 0.5, 1, 4, and 6. The results indicate that POM can usefully reveal grain and subgrain structures over a large field in aluminum. TEM is most suitable to study dislocation substructure and evolution of subgrains. While TEM microscopy and OIM are capable of resolving individual subgrains, OIM can not reliably distinguish subgrains with small misorientations, particularly in samples with low strain. On the other hand, the OIM technique is very useful in the analysis of many regions surrounded by high, medium, and low angle boundaries (HAB, MAB, LAB). Various misorientation maps were studied using different data processing methods. The analysis revealed that the subgrain size is relatively insensitive to strain. The fraction of low LAB ( < 5°) decreased and HAB (>15°) increased conversely with increasing strain, whereas MAB (5-15°) remained stable. The development of an increasingly bimodal grain boundary misorientation distribution is consistent with the predominance of dynamic recovery (DRV) in the evolution of microstructure, combined with geometrical dynamic recrystallization (gDRX), now called grain-refining DRV.

Jan 1, 2006

By Diego L. Romero, Joy P. Romero

"IntroductionThe purpose of this paper is to explain the theory and demonstrate the industrial applications of electrostatic separation. Wabush Mines' use of this type of processing for the concentration of iron ore is unique in the industry. Other minerals are concentrated electrostatically but the process is not widely used.Typical minerals separated by electrostatic separation techniques are:Non-ConductorsAnhydriteApatiteBariteBastnasiteBerylCalciteChrysotileCorundumDiamondEpidoteFeldsparsFluoriteGarnetGypsumHornblendeKyaniteAcmiteAugiteBrookiteCassiteriteChalcopyriteChromiteColumbiteCopperDaviditeEuxeniteFerberiteFrankliniteGalenaGoldGraphiteHematiteMica (Biotite)Mica (Muscovite)MonaziteOlivinePerovskiteQuartzScheeliteSideriteSillimaniteSpheneStauroliteSulphurTopazTourmalineXenotimeZirconConductorsIlmeniteIlmenite-( High Iron)IlvaiteKoppiteMagnetiteMarmatiteMolybdenitePyriteRutileSamarskiteSphaleriteTantaliteWolframiteWulfeniteThe limitations of this process are:1. There must be a difference in conductivity between the minerals being separated.2. The size range must not be very wide.3. The specific gravity of minerals being separated should be similar or the minerals to be pinned should be lighter. 4. The feed must be dry.5. The particle shape should be more or less uniform. 6. The feed must not be high in true middling particles."

Jan 1, 1989

By Matthew Russell, Bobby Randhawa, Leopoldo Mariscal Samaniego, Jose A. Puente, D. Brosig, Paykan Safe

The La Caridad copper smelter, located in Nacozari, Mexico, have started a multi-year plan to reduce sulfur dioxide and particulate matter emissions into the environment. In 2014 the smelter completed a voluntary plant-wide SO2 process emissions inventory as part of the smelter’s proactive environmental stewardship policy. In turn, this triggered the development of several environmental projects to alleviate these emissions. A strategy consisting of improved capture efficiency of the sources with greatest impact has been followed to maximize cost-effectiveness. The reduction of secondary emissions from the Teniente Converter, as well as of primary and secondary emissions from the Peirce-Smith Converters have been key areas of priority. Additionally, a new system to capture and recover particulate matter from the Anode Refining Furnaces off-gas is also in the process of being implemented. This paper presents an overview of the work developed behind this effort and the smelter’s vision towards a greener future. INTRODUCTION The La Caridad copper smelter is owned and operated by Metalurgica de Cobre S.A. de C.V. (a subsidiary of Grupo Mexico). Currently, the smelter has a production capacity of 300,000 tonnes of anodic copper per year. The smelter is coupled with a 300,000 t/y electrolytic refinery. Other by-products (such as precious metals and sulfuric acid) are also generated as part of an integrated process. The original smelter started operating in 1986 with one Furukawa concentrate dryer, one Outokumpu Flash Smelting Furnace (FSF), two slag cleaning electric furnaces (SCFs), three Peirce-Smith Converters (PSCs), two Anode Refining Furnaces (ARFs) and one casting wheel. In 1997, a plant expansion project was concluded with the installation of one steam dryer, one Modified Teniente Converter (MTC), one additional ARF, one additional casting wheel, and the electrolytic refinery [1]. Over the years, the smelter management has implemented numerous environmental projects to alleviate SO2 and particulate matter (PM) emissions. The smelter process gas handling system captures the process gases from the FSF, MTC, and the three PSCs. The process gases are cleaned and conditioned and sent to the two acid plants. The first acid plant (with a capacity of 226,000 Nm3/h, wet basis) was commissioned in 1988 to process the FSF and PSC off-gases. A second acid plant (with a capacity of 195,000 Nm3/h, wet basis) was commissioned as part of the smelter expansion project [1]. The PSCs also have a secondary gas handling system with a dedicated baghouse and stack. The Furukawa dryer off-gas reports to a dedicated electrostatic precipitator (ESP) for dedusting before venting via a local stack. Process gas from the two SCFs, along with hygiene ventilation from various sources inside the smelter (including matte and slag tapping hoods from the FSF) report to a baghouse-based gas handling system and vent to atmosphere via a local stack. The original ARFs do not have an off-gas handling system, however, each ARF has a post- combustion chamber which naturally vents the process gases to the atmosphere via a dedicated stack.

Jan 1, 2019

By S. Koski, J. Vanderbeek, J. Enriquez

"The Cerro Verde copper-molybdenum porphyry mine, majority owned and operated by Freeport- McMoRan Copper & Gold, is located 30 km southwest of Arequipa Peru. The concentrator, which produces copper and molybdenum concentrates, started operating in late 2006 with a 108,000 tpd design capacity, processing primary sulfide ore (mainly chalcopyrite and molybdenite). Plant capacity was recently increased to 120,000 tpd. The comminution circuit consists of one 60” x 113"" primary crusher, four MP-1000 secondary crushers in closed circuit with dry screens, four 2.4m x 1.6m High Pressure Grinding Rolls (HPGRs) in closed circuit with wet screens, and four 7.3m x 11m gearless ball mills in closed circuit with cyclones. The HPGR circuit is fed by the Secondary Crushing circuit product at a T80 of 35 millimeters, and the HPGR circuit product feeds the Ball Mill circuit at a T80 of 3000 microns.This paper describes operating experiences with HPGRs during these first four years highlighting improvements in operating practices and presentation of data regarding operational efficiencies, also discussed are the primary benefits provided by HPGRs such as production of micro fractured particles, reduced ore Bond Work Index, and reduced power consumption. Cerro Verde represents the first installation of HPGRs in both the copper industry and large scale hard rock mining."

Jan 1, 2012

By K. Oishi

We have developed a 76Cu-3Si-21Zn alloy "ECOBRASS®" containing no lead. When 3% Si is added to a 78Cu-22Zn alloy, kappa and gamma phases participate uniformly in the alpha matrix. When being machined, stress concentrates on these hard phases, namely kappa and gamma, and thereby lowering the required cutting force and yielding segmentalized chips without lubricant. Kappa and gamma phases transform into beta phase under high temperature, which makes it easier to extrude and/or forge the alloy. When 0.08% P and 50 ppm Zr are co-added, the grains of ECOBRASS® castings are refined significantly to become as small as several dozens of micrometers. The grain refinement by the co-addition of P and Zr improves castability, tensile strength and elongation of ECOBRASS® castings. Meanwhile, the lead leachate from an ECOBRASS® water meter, field-tested in pH 6.8 drinking water for one year, was less than 5 ppb without correction. No indication of dezincification corrosion was observed, either. ECOBRASS® is equally suitable for rods, forgings and castings, and makes it possible to produce a complete set of plumbing parts (valves, faucets, etc.) by its own. This way, not only improving recyclability, ECOBRASS® also realizes size and weight reduction due to its good corrosion resistance and high strength.

Jan 1, 2007

By Guohong Yin

Oxidized sulfidic tailings contain significant amounts of accumulated acidity in the form of water-soluble secondary sulfate minerals and thus constitute long-term sources of acid drainage at many metal mining sites. As part of site remediation activities, alkaline amendments are often added to the oxidized tailings to increase the pH and immobilize the metals. This study assessed the advantages and limitations of using lime mud, a byproduct of Kraft pulp mills rich in calcium carbonate (> 90 wt. %), as alkaline amendment. The inorganic and organic constituents of lime mud samples were quantified. Leachable impurities were determined by the TCLP method. The performance of lime mud was compared to that of reagent grade quicklime (CaO) and calcite (CaCO3). Tailings treated with lime mud or calcite have strong buffering capacities and remain at neutral pH conditions (pH ~ 6.7) for long times. In contrast, tailings treated with quicklime have a very low buffering capacity, and their pH decreases with time. Furthermore, lime mud has finer particle sizes and thus a greater specific surface area than most forms of commercially available calcite, which results in enhanced reactivity. Dissolved metal concentrations are similar in tailings slurries treated with lime mud or calcite. This study suggests that lime mud is an environmentally and economically attractive alkaline amendment for oxidized mine tailings.

Nov 1, 2002

By C. Han, S. J. Zhou, Y. B. Shen, D. Z. Wei, P. Fang

"Collecting property of two hydroxamic acid collectors have different type of nonpolar structure to hemimorphite has been comparatively studied via monomineral flotation test, and the reason causes different collecting performance has been discussed from the view of relationship between molecular structure and collecting property. The flotation tests results show that C5-9 hydroxamic acid has an unbranched linear alkyl nonpolar group shows better collecting property to hemimorphite than cyclohexyl hydroxamic acid which has a naphthenic nonpolar group. FTIR detecting results show that the adsorption type of collector adsorbed on hemimorphite surface is chemical adsorption. Calculation results of polar group’s geometric structure parameters, polar group’s electron density distribution, octanol-water partition coefficient (logP) and molecular frontier orbital energy show that the key factor caused different collecting property of two collectors to hemimorphite is the logP; unbranched linear alkyl nonpolar group is more conducive than naphthenic nonpolar group to make hemimorphite particle more hydrophobic.INTRODUCTIONZinc-bearing mineral recovered from lead-zinc ores is the main source that people can obtain zinc resource from nature. However, natural sulfide ores are currently getting depleted steadily for the primary zinc source. In order to satisfy the future demand of zinc resource, there is an obvious recognition that the recovery of zinc oxidized minerals from the ores is a crucial alternative (Hosseini & Forssberg, 2007; Navidi Kashani & Rashchi, 2008).But the fact that can’t be ignored is the flotation of zinc oxidized minerals is much more difficult than that of zinc sulfide minerals, which is mainly due to the flotation characteristics of these zinc oxidized minerals such as lower selectivity and higher reagent consumption, as well as complex and variety of lead-zinc ores. Presently, there have been many various beneficiation technologies used for recovering zinc oxidized minerals and dealing with ores for recovering metallic zinc such as flotation and hydrometallurgy (Abkhoshk, Jorjani, Al-Harahsheh, Rashchi, & Naazeri, 2014; Önal et al., 2005). But from an overall perspective, flotation is the most common method used for the beneficiation of zinc oxidized minerals, and there have been extensive investigations conducted on the flotation of zinc oxide ores (Ejtemaei, Gharabaghi, & Irannajad, 2014). Until now, the most well-known method used commercially for the flotation of zinc oxidized minerals is sulfidization with sodium sulfide and flotation with a cationic collector of amines containing from 8 to 18 carbon atoms. However, a major problem for this method is the large amount of fines and slime results in the increase of reagent consumption and promotes the phenomenon of slime-coating. For preclude this negative effect, the de-sliming and processing optimization is indispensible (Peres, Borges, & Galery, 1994; Salum, de Araujo, & Peres, 1992)."

Jan 1, 2016

By Ken G. Stowe, Stephen L. Chryssoulis, Christian Bendel, Joe Y. Kim, Ewald Niehuis

"TOF-SIMS (Time-of-flight secondary ion mass spectrometry) was used to detect collectors sorbed onto the surface of mineral particles in concentrate and tailings samples from the Brunswick, Matagami and Kidd Creek concentrators. This technique uses ion beams from either Cs or Ga sources to sputter the particle surface, a method which reduces fractionation of the collector molecule during sampling.In the Brunswick Zn circuit, sphalerite particles lost to the scavenger tails had less amyl xanthate and isobutyl xanthate compared to sphalerite recovered to the Zn final concentrate. Xanthates were detected on the surface of sphalerite particles floating to the CuPb final concentrate.At Matagami, significantly more isopropyl xanthate and isobutyl dithiophosphate were detected on sphalerite recovered to the Zn final concentrate, compared to sphalerite lost in the Zn rougher tails.In the Zn circuit of Kidd Creek, sphalerite lost to the tails had on average ten times less xanthate compared to sphalerite recovered into the Zn final concentrate. Xanthate was also detected on the floated pyrite particles. In addition to isobutyl xanthate, amyl xanthate was also detected on the floated sphalerite and pyrite particles.This preliminary investigation has (a) demonstrated the ability of TOF-SIMS to detect individual collectors on particle surfaces from plant samples and (b) shown that TOF- SIMS is an excellent tool, complimentary to TOF-LIMS, in establishing the surface chemistry of minerals as related to mineral processing."

Jan 1, 1995

By C. Sui, J. E. Nesset, M. Li, J. Y. Kim, S. L. Chryssoulis

"A plant study of zinc rougher flotation at Brunswick Mining was conducted using lime, soda ash and a combination of both as the pH modifiers in order to establish the effects on sphalerite and pyrite kinetics and mineral selectivity. The plant sampling and analysis was augmented by surface analysis using TOF-LIMS, SEM and XPS as well as fundamental precipitation and surface-charge studies in the sphalerite Ca/C03/S04 system.The results revealed the important role of carbonate ions in cleaning the sphalerite surface for effective activation by CuS04 to occur, and the beneficial role of combined soda ash and lime in increasing pyrite and galena depression.1.0 IntroductionThe studies reported in this paper were initiated as part of an investigation into the causes of a particularly pronounced seasonal deterioration in metallurgical performance at the Brunswick Mining concentrator during the summer of 1995. The concentrator treats a complex base metal ore having a typical feed composition of 9.0% Zn, 3.5% Pb, 0.4% Cu and 100g/t Ag at a current throughput of 9,000 TPD, although at the time of the problem in 1995, the average production rate was closer to 10,500 TPD. Zinc, lead, copper and bulk (zinc-lead) concentrates are produced with overall metal recoveries of 86% zinc, 63% lead, 60% copper and 60% silver; results which are typical of the lower recoveries associated with fine-grained, highly complex VMS and SEDEX type deposits. The main economic minerals of interest are an iron-containing (7% Fe) sphalerite, galena and chalcopyrite with the main diluent (about 60% wt) being pyrite.Figure 1 shows a simplified flowsheet of the Brunswick milling circuit while the seasonal decrease in summer metallurgy in 1995 is illustrated in Figure 2. Of significance is the rapid drop in copper and lead recovery in June while there is an apparent delay until late August-September before the zinc deterioration reaches its lowest point. A more typical seasonal effect within the experience of the authors is the reverse of the Brunswick situation, namely an improvement in summer performance thought to be associated with improved differential flotation kinetics during warmer weather leading to better mineral selectivity. The historical Brunswick experience was particularly severe during the summer of 1995 with estimated incremental losses of $10 Million for this period. The potential of the very significant economic benefits to be gained from understanding and hopefully improving the annual drop in performance led to an investigation involving the minesite metallurgical group, the Noranda Technology Centre (NTC) as well as researchers in Professor Jim Finch's group at McGill and the surface analytical services and interpretive skills of AMTEL."

Jan 1, 1998

By J. P. Grieco, F. W. Grieco

"Manufacturing of Jaw CrushersOriginIn 1858 Eli Whitney Blake invented the first successful mechanical rock breaker-the Blake-type jaw crusher. Blake adapted a mechanical principal, the powerful toggle linkage system used to transform rotating motion and energy into oscillating mot ion and tremendous compressive forces. Today these same principals apply and the basic Blake-type jaw crusher is one of the leading machines of its class for heavy duty primary crushing service.In 1881 Philetus W. Gates patented a design for a crusher, the forerunner of the modern gyratory crusher which dominated the field from the late 1800s to the early 1900s. In 1910 the largest gyratory crushers built had 48-inch openings. However, about this time the jaw crusher came to life when the Power and Mining Machinery Co. built an even larger sized opening crusher-a giant 84-inch by 60-inch jaw crusher for a trap rock quarry in Pennsylvania. A 24-inch gyratory crusher became the ideal sized secondary machine for this size jaw. From that time on jaw crushers were looked on favourably as primary breakers and lines were brought up to date to parallel the already developed gyratory lines.FunctionMost heavy duty Blake-type jaw crushers work basically the same way. They are ruggedly designed and capable of crushing material in some cases in excess of 80, 000 p.s.i. compressive strength. They are very simple machines with few moving part s and, with the exception of replacement of renewable parts, are relatively maintenance free. It is quite common to have these machines in product ion for 20 to 30 years. The following will de scribe how these machines work. Large-diameter high-inertia flywheels which are connected to the main eccentric shaft, rotate inside a connecting rod type mechanism called a Pitman. It transforms rotating motion into vertical oscillating motion. This vertical motion is in turn transformed into reciprocating mot ion by means of a system of 2 toggles, each connected to the Pitman. The rear toggle is connected to the fixed rear head, and the front toggle is connected to the swing jaw which is hinged at the top of the crusher. With each rotation of the eccentric shaft the swing jaw opens and closes on rock which is fed into the crusher chamber, crushing the rock in a series of bites. These bites, or strokes as the y are called, usually vary between 1/2 inch to 1 1/2 inch at speeds of 120 to 200 strokes per minute. The reduction ratio of feed input to discharge is usually about 8 to I. Output capacities can vary from 100 tons/hour to 1200 tons/hour depending on the size of machine and its discharge opening. Horsepower requirements can vary from 75 hp to 400 hp.The entire crusher chamber is lined with replaceable 14070 manganese steel liner plates. This material is ideally suited for the job since it hardens as it wears during crusher operation. Manganese is also used in the high wear areas at each end of the toggle plates."

Jan 1, 1985

By J. P. Grieco, F. W. Grieco

"Manufacturing of Jaw CrushersOriginIn 1858 Eli Whitney Blake invented the first successful mechanical rock breaker-the Blake-type jaw crusher. Blake adapted a mechanical principal, the powerful toggle linkage system used to transform rotating motion and energy into oscillating mot ion and tremendous compressive forces. Today these same principals apply and the basic Blake-type jaw crusher is one of the leading machines of its class for heavy duty primary crushing service.In 1881 Philetus W. Gates patented a design for a crusher, the forerunner of the modern gyratory crusher which dominated the field from the late 1800s to the early 1900s. In 1910 the largest gyratory crushers built had 48-inch openings. However, about this time the jaw crusher came to life when the Power and Mining Machinery Co. built an even larger sized opening crusher-a giant 84-inch by 60-inch jaw crusher for a trap rock quarry in Pennsylvania. A 24-inch gyratory crusher became the ideal sized secondary machine for this size jaw. From that time on jaw crushers were looked on favourably as primary breakers and lines were brought up to date to parallel the already developed gyratory lines.FunctionMost heavy duty Blake-type jaw crushers work basically the same way. They are ruggedly designed and capable of crushing material in some cases in excess of 80, 000 p.s.i. compressive strength. They are very simple machines with few moving part s and, with the exception of replacement of renewable parts, are relatively maintenance free. It is quite common to have these machines in product ion for 20 to 30 years. The following will de scribe how these machines work. Large-diameter high-inertia flywheels which are connected to the main eccentric shaft, rotate inside a connecting rod type mechanism called a Pitman. It transforms rotating motion into vertical oscillating motion. This vertical motion is in turn transformed into reciprocating mot ion by means of a system of 2 toggles, each connected to the Pitman. The rear toggle is connected to the fixed rear head, and the front toggle is connected to the swing jaw which is hinged at the top of the crusher. With each rotation of the eccentric shaft the swing jaw opens and closes on rock which is fed into the crusher chamber, crushing the rock in a series of bites. These bites, or strokes as the y are called, usually vary between 1/2 inch to 1 1/2 inch at speeds of 120 to 200 strokes per minute. The reduction ratio of feed input to discharge is usually about 8 to I. Output capacities can vary from 100 tons/hour to 1200 tons/hour depending on the size of machine and its discharge opening. Horsepower requirements can vary from 75 hp to 400 hp.The entire crusher chamber is lined with replaceable 14070 manganese steel liner plates. This material is ideally suited for the job since it hardens as it wears during crusher operation. Manganese is also used in the high wear areas at each end of the toggle plates."

Jan 1, 1985

The influence of joint orientation and joint persistence, on the mechanical behaviour of jointed rock masses under uniaxial compression, has been studied systematically. The joint inclination angle ß was varied from 0° to 90° with an increment of 15°. The joint continuity factor k was taken as 0.2, 0.4, 0.6 and 0.8. The peak strength, Young’s modulus, the complete axial stress-axial strain curves, the cracking process and the characteristic of the fragments, were investigated. It was found that the anisotropic response of the jointed specimens was governed by the micro-mechanism, such as crack initiation, propagation and coalescence, crack opening or closing, and frictional slip of cracks or joints. With the increase of joint continuity factor, the axial stress-axial strain curves change from single-peak to multipeak, the peak strength and Young’s modulus decrease. The specimens with medium joint inclination angle (30°,45° and 60°) has lower energy dissipation and strength due to stepped or shear failure, while specimens with small and large joint inclination angle (0°, 15°, 75° and 90°) has higher energy dissipation and strength due to axial cleavage or crushing failure.

Jan 1, 2015

By M. X. Yao, Y. Ning, P. C. Patnaik, R. Liu, X. J. Wu

Stellite 712 composites were developed with the reinforcement of bare TiC or Ni-coated TiC particles using HIPing powder consolidation technique. The emphasis of this research was on the effect of the Ni coating on the TiC particles and the HIPing conditions on the microstructure and performance of the composites. Calorimetric effects of the mixed composite powders were investigated using the differential scanning calorimetry (DSC) technique before the HIPing process, which provided the basis of the HIPing cycles designed. The microstructures of the composites were examined using SEM with EDX. The hardness and wear resistance of the materials were evaluated respectively. It was found that the HIPing temperature influenced the microstructure and the performance of the materials. The Ni coating on the TiC particle has improved the fracture toughness of the composites, but detracted the wear resistance. The experimental results and relevant mechanisms were discussed.

Jan 1, 2004