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By George Hope, Dave Green, Jacques McMullen

The Est Malartic mill has been treating massive sulphide, copper/gold ore from the Bousquet 2 mine since 1989. The need to minimize copper content in flotation tails which are leached for gold recovery and to produce a saleable copper concentrate led to the evaluation of Conventional, Column and HG flotation methods. The HG method was preferred and two full-scale cells were installed and operated over a two-year span. In 1992, it was decided to expand the mill capacity from 1500 tpd to 2500 tpd. A total of nine additional HG Tank Cells were installed to provide additional roughing and cleaning capacity. The expanded plant has been operating since June 1993.

Jan 1, 1994

By G. Brooks, M. Hamed, S. Nightingale, K. Coley

The Marangoni effect plays a significant role in slag line corrosion of refractories. Previous experimental studies for various refractory /slag systems and mathematical models are reviewed and show that Marangoni flow is important in slag line corrosion under static conditions. Recent work by the authors is presented which also shows significant slag-line corrosion of MgO refractory in SiO2-CaO-FeOx-MgO slag. The rate of attack of the MgO was marginally slower in the case of slags containing alumina. A semi-empirical model developed by Hrma based on mass transfer control described reasonably well the observed progression of corrosion with time. Further work is proposed to evaluate this model.

Jan 1, 2004

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

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 T. Hadley, Northern Minerals Ltd, C. S. Griffith, T. A. Safinski, K. H. Soldenhoff, M. Fainerman-Melnikova, A. Manis

"ANSTO Minerals and Northern Minerals have been working together since 2012 on the process flowsheet development for the Browns Range project for the recovery of the heavy rare earths (Dy – Lu, + Y). Initial efforts were directed toward defining the most efficient and direct flowsheet for the Preliminary Feasibility Study (PFS), issued in June 2014, then towards the Definitive Feasibility Study (DFS), issued in February 2015. These goals were achieved by undertaking comprehensive laboratory and continuous piloting programs. Further improvements to the flowsheet following the DFS have been made. This publication provides an overview of the evolution of the process flowsheet based on these laboratory and piloting programs from the PFS through the DFS and beyond.INTRODUCTIONNorthern Minerals Ltd (Northern) has been working on developing their flagship project at Browns Range for the recovery of the heavy rare earth elements (HRE, Dy – Lu, + Y). The project is located in the north of Western Australia as shown in Figure 1. The Total Mineral Resource at the project is currently estimated at 8.98 Mt @ 0.63% total rare earth oxides (TREO) comprising 56,663 t of contained TREO using a cut-off grade of 0.15% TREO. Of the Total Mineral Resource, 58% is classified as Indicated Resource, with the remainder in the Inferred Resource category.The deposit is characterised by breccia-hosted, hydrothermal, HRE-rich, xenotime mineralisation. The main gangue mineral associated with the xenotime is quartz. The distribution of rare earths (RE) observed for the xenotime mineralisation at Browns Range is presented in Figure 2. Extensive test work has shown that the xenotime can be readily beneficiated to between 20 – 40% rare earth oxide (REO) using a process consisting of crushing and grinding, followed by magnetic separation and flotation steps. Continuous piloting of this process was conducted on ~80 t of trench-sourced ore in late 2013 at SGS Perth, to produce ~2 t of ~20% REO mineral concentrate (MC) for hydrometallurgical testing. The composition of the MC produced during piloting is presented in Table 1."

Jan 1, 2016

By T. L. Carpenter

"The presence of excessive water in the Gibraltar East Stage 1 pit initiated studies into the ground-water conditions that might be expected in mining the Granite Lake and Pollyanna pits. Hydrologic information obtained from a pump test program in 1974 indicated that deep-well dewatering could be successfully achieved. In 1976, a deep-well dewatering system consisting of eight wells was installed on the periphery of the Pollyanna pit . it has been responsible for a significant decrease in mining costs.This paper presents a brief summary of the engineering principles involved in the design of the Gibraltar dewatering system and the problems encountered in the installation and operation of deep-well pumps. IntroductionGibraltar Mines is an open-pit copper-molybdenite mine located approximately 230 air miles north of Vancouver in the central interior of British Columbia (Fig. I). The property consists of three separate major orebodies; Gibraltar East, Granite Lake and Pollyanna (Fig. 2). Mining commenced during the summer of 1971, in the Gibraltar East Stage 1 pit. The Granite Lake Stage 1 pit was mined from mid 1974 to mid 1976. The Pollyanna Stage 1 pit is currently being mined and the Gibraltar East Stage 2 is being developed for production. This report is intended as an outline of the studies and tests leading up to and including the installation of the Pollyanna pit dewatering system, the problems encountered and the results obtained.GeneralIn the summer of 1973, mining in the Gibraltar East pit progressed below ""daylight"" on the down-hill side and ground water very quickly became a costly nuisance in the day-to-day mining operations. Mining, maintenance and blasting costs reflected these problems. Concern was also voiced about adverse effects of ground water on pit wall stability. This concern later became a reality in the Gibraltar East and Granite Lake pits. A study was initiated to investigate various methods and costs of dewatering the pit areas. The study included in-pit sumps, deep peripheral wells and a drainage gallery system located below the pits."

Jan 1, 1980

By Hajime Miki, Gde Pandhe Wisnu Suyantara, Ahmed Mohamed Elmahdy, Hidekazu Matsuoka, Kyushu University, Tsuyoshi Hirajima

"Selective flotation of chalcopyrite and molybdenite was studied using various surface treatment methods such as electrolysis, ozone treatment, and plasma. Oxidation via electrolysis method indicated that only chalcopyrite surface is affected by electrolysis due to conductivity difference with molybdenite. Oxidation treatments and XPS analyses indicated that chalcopyrite became hydrophilic due to deposition of oxidized iron on its surface. Various oxidizing methods also showed that chalcopyrite was selectively oxidized and this can apply selective flotation of chalcopyrite and molybdenite. The possible mechanisms are proposed in this work based on surface analyses and thermodynamic calculations.INTRODUCTIONCopper sulphide minerals often associate molybdenite (MoS2) which is one of the most important by-products (Wills, 2006). It is important to recover molybdenite perfectly not only since molybdenite is valuable mineral, but also contamination of molybdenite into copper concentrate or contamination of copper mineral into molybdenite concentrate indicates penalty for both concentrate values (Wills, 2006). Conventional separation of copper sulphide and molybdenite has been achieved with sulphide bulk flotation followed by selective molybdenite flotation with NaHS addition since NaHS works as a depressant for copper sulphide. However, this current process shows imperfect molybdenite recovery and depressant such as NaHS needs to be used under specific flotation plant since it might be environmental contaminant. Hirajima et al., (2014) have been studied selective flotation of molybdenite and chalcopyrite (CuFeS2), which is the most important copper mineral, with plasma pre-treatment. They reported that plasma pre-treatment process followed by washing treatment can improve molybdenite floatability and depress chalcopyrite. This result is attributed to surface oxidation and selective conversion of chalcopyrite and molybdenite wettability. It may be hypothesized that another surface oxidation methods could give a similar result as plasma treatment process. To test this hypothesis, in this study, as comprehensive study of oxidation effect, various oxidation methods such as electrolysis, ozone, and plasma were investigated. Electrochemical measurements, thermodynamic calculations to predict the chemical reactions happened during the process, various surface analyses, and flotation experiments were carried out."

Jan 1, 2016

By P. E. Weidmark

"PART I - Published PapersBallivy, G., and Dupuis, M., ""Laboratory testing for the design of grouted rock anchors""; Proc 6th Pan Am Conf Soil Mech Found Eng; Lima; 1:277-291; 1979.Ballivy, G., Ladanyi, B., and Gill, D., ""The effects of moisture content on the strength of fissured rocks""; Proc 1// 1ntnl Congr 1.A.E.G.; Madrid; //:2:7-16; 1978.Baumgartner, P., and Stimpson, B., ""Development of a tiltable base friction frame for kinematic studies of caving at various depths""; Int J Rock Mech Min Sci Geomech Abstr; 16:4:265-267; 1979.Bawden, W.F., and Roegiers, J.-c., ""Discussion and interpretation of the mathematics governing radial flow in a single horizontal rock fracture""; ISBN 07727-7002-6; Dept Civil Engng publication 79-11; Univ Toronto: 134p;1979.Chatterji, P.K., Smith, L.B., and Insley, A.E., ""Construction of Saline Creek Tunnel in Athabasca oil sand""; Can Geotech J; 16:1:90-107: 1979.Coates, D.F., and Gyenge, M., ""A case history of pit slope design""; Proc 4th ISRM Congr; Montreux, Switzerland; Sept 1979; 1:Theme IV:591-596; 1979.Crawford, A.M., and Curran, J.H., ""A dynamic direct shear machine for determining the time-dependent behaviour of rock joints"": Dept Civil Engng publication 79-08; Univ Toronto; 1979.Crawford, A.M., and Curran, J.H., ""A displacement discontinuity approach to modelling the creep behavior of rock and its discontinuities""; Dept Civil Engng publication 79-09; Univ Toronto; 1979.Crawford, A.M., and Curran, J.H., ""A higher-order displacement discontinuity element""; Dept Civil Engng publication 79-10; Univ Toronto; 1979.Cruden, D.M., ""A computer-based system for rock mass description""; Proc 1// Intnl Congr I.A.E.G.; Madrid; //:2:155-159; 1978.Cruikshank, D.J., and Curran, J.H., ""A.B.LE. approach to modelling of fluid flow in fractured rock masses""; Proc 7th Cdn Congr Appl Mech; May 1979; Sherbrooke, Que; 887-888; 1979."

Jan 1, 1980

By V. Nudo, R. del Villar, A. R. Laplante

"Fine iron ore recovery from the tails of Les Mines Quebec Cartier was investigated using Reichert trays and spirals. The effect of feed rate, density and splitter setting on the performance of rougher, cleaner and recleaner stages of a 2DS tray assembly was determined using 2- and 3- factorial experimental designs. The tray concentrate, assaying 27% Fe, was further upgraded by spiral to yield a concentrate assaying 55% Fe. Further laboratory scale testing showed this material to be easily upgraded to 65-66% Fe with high Fe recoveries.This paper presents the metallurgical results of the three tray stages. The model used to predict the performance of a full recovery circuit is then described. Simulation results are presented and their reliability assessed. Finally, an economic evaluation of the proposed scavenging circuit is summarized.INTRODUCTIONThe Mount Wright plant (UWP), located near Fermont, Quebec, processes daily 130,000-150,000 tonnes of iron ore assaying between 27 and 33% Fe, to upgrade it with three stages of 44.5 cm pitch GEC spirals to 66% Fe, while rejecting approximately 80,000 tonnes assaying between 6 and 11% Fe (1-3). Heavy liquid separation (at 3. 3 g/mL) of the plus 37 µm fraction (+400 mesh) of the tails reveals that a significant fraction of the iron is in the sink product, below 150 pm (100 mesh), as shown in Table 1. Also shown is the iron grade of the sink and float fractions. The high grade of the fine sink indicates that hematite ls well liberated below 105 µm (150 mesh), as previous studies have shown (4,5). The iron grade of the floats is very low in the fine size range, but increases with increasing size above 105 pm, because of incomplete liberation. Overall, two thirds of the plus 37 µm iron ls in the sink product, which constitutes less than 10% of the total tail."

Jan 1, 1987

By Kazuteru Tozawa, Robert G. Robins

"The stability of calcium arsenate is discussed in relation to the possible misuse of lime in the treatment of gold processing waste waters. Stability diagrams have been derived and experimental results cited to show that calcium arsenate has a higher solubility in neutral to alkaline solution than has previously been recognized and this solubility is further enhanced by the presence of carbon dioxide, bicarbonate or carbonate.IntroductionThe removal of arsenic from gold mine waste waters has been of interest for more than thirty years, but with the recent emphasis on clean water standards there has been renewed activity in relation to that problem. The processing of gold-bearing sulphides which contain arsenopyrite and other complex arsenic sulphides is well established. Initial roasting to oxidize the sulphides leaves the arsenic in the form of both arsenic and arsenic, in which forms it is soluble in the subsequent leaching stage. Further oxidation of the leach liquors is required before the well-established procedure of precipitating calcium arsenate with lime, which is carried out despite an immense lack of knowledge of the calcium-arsenic-water system.The solubility product and free energy of formation for Ca3(AsO4)2, which are to be found in recent and reliable sources of data, originate from the work of Chukhlansev, whose experimental determination of the concentration of calcium from the solubility of calcium arsenate in solutions of various pH yields the results plotted in Figure 1. This is the work which has resulted in a wide acceptance of the ""insolubility"" of calcium arsenate and the use of lime to stabilize arsenic in that form.Laguitton attempted to further elucidate the chemistry of the lime addition method for treating arsenical waste waters from gold processing operations. The low solubility product for Ca3(AsO4)2 was the basis for his examination of likely chemical equilibria in the system. Laguitton and other workers have not considered atmospheric carbon dioxide as an important component in this system."

Jan 1, 1982

By Charle Lawrence, Murray E. Blanchard

"A significant addition to Canada's commodity export transportation capabilities is being built by Ridley Terminals Inc. on Ridley Island in the Port of Prince Rupert on British Columbia's north coast.Site preparation began in early 1982. By the end of 1983 the terminal will be receiving coal from two major new mines being developed in B. C.'s massive $2.5 billion northeast coal development.The RTI terminal will have initial capacity to transfer 12 million tonnes of coal a year from railcars to storage and to ships. Capacity will be doubled to 24 million tonnes as market opportunities are developed.The challenge of building this $220-million facility in less than 24 months, the benefits Canada has received from the work the project is generating, and the long-term faith in Canada that this project represents, are all part of the excitement which surrounds the Ridley Terminal and northeast coal developments.RIDLEY TERMINALS INC. (RTI) is building a very significant addition to Canada's commodity export transportation capabilities. The facility, on Ridley Island at Prince Rupert, on the north coast of British Columbia, is a key link in British Columbia's northeast coal development which in itself is a massive undertaking involving investment of some $2.5 billion. The entire project is making a substantial contribution to Canada's economy at a time when such contributions are sorely needed.The development is creating employment, not only in British Columbia where its various parts are being created by mining companies, railways and others, but also across the country where suppliers are manufacturing a wide variety of good s and equipment for the development's participants.The RTI terminal is no exception. It is a critical cog in this mega project's large transportation system and its construction is contributing substantially to job creation and to other economic activity, in the Prince Rupert area and in many other parts of British Columbia and the rest of Canada."

Jan 1, 1983

By J. -P. Tshibangu, M. Ramos da Silva, F. Descamps, C. Schroeder, J. -C. Verbrugge

"The mechanical behaviour of rock materials is largely influenced by the stress state and pore pressure; this needs to be considered in many applications, such as petroleum engineering, tunnelling or stability of underground excavations.Conventional triaxial tests (d2 = d 3) are generally used to assess the influence of confining and pore pressure. In this work, those tests are performed on a porous rock named Sorcy limestone, along with more advanced stress paths like triaxial extension (d 2 = d 1) and purely deviatoric tests with independent pore pressure control. Those tests are combined to a true triaxial study on the dry rock in order to investigate the effect of true triaxial stresses and, hence, build three-dimensional limiting envelopes accounting for the influence of pore pressure.Three-dimensional limiting envelopes of dry Sorcy limestone are built in meridian and octahedral planes. The shape of the octahedral sections changes with the mean stress from triangular to hexagonal and then quasi circular. At even higher mean stresses, the evolution continues towards a triangle with apexes oriented in the direction of triaxial extension stress states. In meridian sections, the deviatoric stress first increases with the mean stress. The transition between this deviatoric mechanism and the cap surface occurs at different mean pressures depending on the Lode angle.Terzaghi’s effective stress is found to govern the yield and plastic behaviour of saturated Sorcy limestone. Triaxial tests show that the limiting envelope does not depend on the loading path (conventional compression and purely deviatoric stress paths). In triaxial extension, the brittle-ductile transition is observed for a higher mean pressure than in triaxial compression, as previously found for true triaxial tests on the dry rock.Finally, it is shown that upon appropriate normalisation, the dry and saturated yield envelopes come very close one to each other. This suggests that only the size of the yield envelope changes between dry and saturated state (pore pressure = 5 MPa); its shape does not seem to evolve."

Jan 1, 2015

By M. Sutherland

"Increased efforts to improve mine safety have led to various successful forms of ground control in Canadian underground mines. At Inca Limited's T-3 Mine in Thompson, Manitoba, a perimeter blasting method has been implemented in jumbo drilled development headings.The technique utilizes an increased number of perimeter blast holes in the drill pattern while decreasing the linear charge density of explosives in any individual perimeter hole. The decrease in perimeter charge density means less blast damage to the surrounding structure.The benefits realized include increased safety through less loose ground and substantially less scaling time, less overbreak and improved long-term drift stability. This paper highlights the development and implementation of the perimeter blasting program.IntroductionThompson Mine Thompson Mine is a 6000 ton per day underground nickel mine located just outside the city of Thompson, 400 miles north of Winnipeg. The mine is serviced by the T-I shaft and by the T-3 shaft. The shafts are 10 000 ft apart and are connected on several levels with the deepest operating levels at T-1 and T-3 being 4000 ft and 2400 ft respectively.The T-3 Mine presently produces 52% of the total Thompson Mine production and 65070 of the 3000 ft of mine development each month. Current development of the 5 million ton 1, C orebody below 2400 level at T-3 will maintain these production and development ratios.Depending on equipment requirements, development headings at T-3 Mine vary in size. The 1, C ramp, at 17 1/2 ft wide by 10 1/2 ft high, is presently the largest development heading at T-3. Fifty- two per cent of the development footage is done with four Gardner Denver two boom electric /hydraulic jumbos and one Gardner Denver one boom electric /hydraulic jumbo. The remaining 48% is driven with hand-held jack-leg drills."

Jan 1, 1990

By I. Stanoev, V. S. Stoilov, I. Gradinarov, E. D. Visariev, I. A. Bonchev, Aurubis Bulgaria

"Aurubis is the leading integrated copper group and the world’s largest copper recycler. In Copper smelter Aurubis Bulgaria (Pirdop), the residual copper in the slags from Flash furnace and Converters is recovered by flotation. The slag processing comprises: pit cooling, crushing, two stages grinding (autogenous and ball) and flotation. The copper concentrate is thickened and then is filtrated by vacuum disk filter. The thickener overflow is sent to settler for additional clarification. A resent throughput increase resulted in higher solid content in the thickener overflow due to insufficient thickener area. Different scenarios to overcome the issue were evaluated (new thickener, reagents and reconstruction). An increase of the thickening area by installation of lamella modules was chosen as the most promising option. Three lamella modules (1 m3 each) were installed in conventional thickener for the test. Number of sampling campaigns was done to evaluate the effect on solid content in overflow. Parameters of the dewatering cycle were collected during sampling campaign. The products grain size distribution was defined - thickener feed, thickener overflow with and without lamella. The thickener overflow with lamella modules has 2.12 g/L less solid content. The decrease was 71.8%. According to the tests results, the whole conventional thickener was reconstructed with lamella modules. The thickener area was increased by more than 400 m2.INTRODUCTIONIn Copper smelter Aurubis Bulgaria, the copper in slag from the Flash furnace and the Converters is recovered by flotation. The scheme of slag processing is crushing, two stage grinding (autogenous and ball) and flotation. Till 2010 the grinding cycle in the plant was in two stages: the first stage was AG Mill 70×23 working with a classifier and the second stage was ball mill 3.6/5.5 working with a hydrocyclone. In 2010 a new AG Mill 65×78 with hydrocyclone was put in operation in order to increase throughput of the plant. The second stage of the grinding cycle was not changed."

Jan 1, 2016

By W. C. Ferguson

"This paper could be more appropriately titled ""The Application of Vacuum Filters to Underground Minewater Treatment. in a previous paper co-authored by the writer (1) the history and development of minewater treatment at the Sudbury District Operations of the International Nickel Company was outlined. It is the intention of this paper to dwell more specifically WIth the the application of the vacuum filter to a problem found in most, if not all, underground mining operations. In the preparation of this paper the writer has made liberal use of the illustrations and text of the paper previously noted.Last year we heard Mr. Nemeth discuss the basic mechanisms involved in vacuum filtration (2), and today Yr. Cunliff has exposed us to the selection of the filter media (3). I will now briefly review the various vacuum filter designs that generally lend themselves to metallurgical dewatering applications.DRUM FILTERSThe revolving drum-type which filters on its outside periphery is illustrated in Fig. 1. This is the Oliver or Drum filter and represents the first commercially available continuous vacuum filter. The original design dates back more than 50 years, but with the exception of the method of discharge, is identical to the units being marketed today. This filter is generally applied to slow filtering slurries. The cake may be discharged in several ways; strings, scraper blades, rolls or by passing the filter cloth over a small diameter discharge roller (belt discharge).THE DORRCO FILTERThe revolving drum type which filters on its inside periphery is illustrated in Fig. 2. Here the slurry lies in the drum and the cake discharges through a chute or conveyor. This type of filter is most often applied to fast-filtering slurries.THE DISC FILTERThe revolving filter which filters on the vertical plane of the disc is referred to as the Disc or American-type filter. This represents the most inexpensive design in terms of cost per square foot of filter area. This filter is widely applied, but is probably more suitable for slower draining pulps."

Jan 1, 1971

By Haibin Wang, Zhiwei Huang, Zhixiang Cui, Wenzhao Cui, Zhi Wang

Fangyuan Two-Step copper smelting process was commercialized in October, 2015 and has been operating for 3 years and 5 months. As the unique continuous copper smelting process with simplified flow in the world, production parameters have been significantly improved after three years. In the first half of 2018, the feed rate was above 200t/h, availability reached 97.5%, operation cost was about 20% lower than the conventional three-step processes showing obvious economic advantages. The Two-Step process in Fangyuan is composed of 1 Submerged Lance Smelting furnace (SLS) and 2 Submerged Lance Converting& Refining furnaces (SLCR). Two SLCRs work alternatively to ensure continuous production. High grade and liquid matte from the SLS is introduced to the SLCR by sealed launder to complete converting and refining. The SLCR is an original and independent innovation of Fangyuan, for which Fangyuan completed lots of development and improvement. This paper will introduce the process and experience. INTRODUCTION China is the largest producer and consumer of refined copper. Most of the processes adopted in China are conventional "Three-Step" copper smelting processes, which are comprised of smelting, converting and refining. There exists some problems in the conventional processes, such as high energy consumption, large heat loss, low altitude emission of SO2, etc. To deal with these problems, Fangyuan developed the new copper smelting process with simplified flow, low cost, clean and high efficiency. The SLCR that combines converting and the refining process was also developed, which shortens the process flow from conventional three steps to two steps. The SLCR is of great significance in promoting the development of the copper industry. Development and industrialization of SLCR At present, copper concentrates are treated in three steps: smelting, converting and refining. Anodes are also produced by continuous converting processes such as the Mitsubishi process and the Double Flash process. Problems like matte transportation by ladle, capacity limitation, and low altitude pollution exist.

Jan 1, 2019

By P. E. Weidmark

"PART 1-Published PapersAllcott, G.A., and Archibald, D.E.; ""Description of pillar behaviour at Heath Steele Mines""; Can Min Metall Bull; 74:834:80-87; 1981.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of rock Mechanics; 3:32-33; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:37-38; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:38; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses"" ; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:41; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:42; 1979.Baar, C.A.; Discussion of Theme 1: ""Physical properties of intact rock and rock masses""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:46; 1979.Baar, C.A.; Discussion of Theme 2: ""Tectonophysics""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:60; 1979.Baar, C.A.; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3: 116; 1979.Baar, C.A.; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:116-117; 1979.Baar, C.A.; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:117; 1979.Baar, C.A. '; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:118-119; 1979.Baar, C.A.; Discussions (2) of Theme 4: ""Underground openings""; Proceedings 3rd Congress lntnl Soc of Rock Mechanics; 3:119; 1979.Baar, C.A.; Discussion of Theme 4: ""Underground openings""; Proceedings 3rd Congress Intnl Soc of Rock Mechanics; 3:120-121; 1979."

Jan 1, 1982

By S. Shokri

The increasing size and complexity of mega construction projects result in having several geographically distributed stakeholders, collaborating with each other to successfully deliver the project. Electronic Product and Process Management Systems (EPPMS) are recently emerging to facilitate the collaboration between stakeholders, reduce the surprises and issues, and improve the project productivity. These are commercially successful but evolving systems. An important component of EPPMS is the Interface Management System, which aims at formalizing and automating the communication channels between stakeholders. An interface is generally considered the link between construction elements, phases, or stakeholders. An interface Management System (IMS) involves five iterative steps: (1) Interface Identification, (2) Interface Documentation, (3) Interface Transferring, (4) Interface Communication, and (5) Interface Closing. A fundamental part of step 2 is recognizing different roles in dealing with interfaces. Each stakeholder is assigned a different role, such as responsible, accountable, consulted, and informed. In a mega project, several thousands of interfaces exist with complex relationships between stakeholders. Therefore, identifying stakeholders with higher responsible roles has been requested as useful information to the project owner in dealing with some of the project risks. After the interfaces are determined, and the responsibilities are allocated, the critical stakeholders are identified using the centrality concept in Social Network Analysis. The critical stakeholders can be determined at the highest level, considering all types of interfaces, as well as for each specific type or discipline-related interfaces. The proposed methodology is applied on a hypothetical offshore project with over 500 interfaces. In fact, this project is a simplified representation of a real scale Liquid Natural Gas project. In order to reduce the complexity of calculations and clarity of explanations, the simplified case study is used. By implementing IMS in mega projects, different parties not only formalize the communication between each other, but also gain better visibility concerning their roles and responsibilities. In addition, the owner benefits from analysing the complex relationships between stakeholders to further identify critical ones, along with other criteria like package cost, stakeholders? experiences, etc.

Aug 1, 2013

By P. A. Riveros

The literature on the arsenic disposal practices of the metallurgical industry and the long term stability of the disposed arsenic compounds were reviewed from a Canadian perspective. The review was complemented with visits to selected operating metallurgical sites to obtain information on their specific arsenic disposal practices and the behaviour of their impounded residues. The arsenic disposal procedure currently favoured by the industry involves the formation of an insoluble ferric arsenate compound which is allowed to sediment at the bottom of tailings or residue ponds. It has been shown recently that this poorly formed crystalline compound is similar to ?arsenical ferrihydrite? which is ferrihydrite containing strongly adsorbed arsenate anions. Despite concerns about its long term stability on thermodynamic grounds, arsenical ferrihydrite appears to be stable for many years in the proper environment which includes a slightly acidic pH and oxidizing conditions. A high Fe/As ratio and the presence of heavy metals appear to increase the stability of arsenical ferrihydrite. High temperature operations, such as those encountered in the autoclave treatment of refractory gold ores, are conducive to the formation of scorodite, FeAsO42H2O, and/or a series of ferric arseno-hydroxy-sulphate compounds depending on the solution composition. Scorodite has several advantages over arsenical ferrihydrite as a disposal compound including a lower iron demand, a higher density and a greater thermodynamic stability. New procedures have been developed to generate scorodite at ambient pressure. These procedures would offer significant reductions in capital cost because of the elimination of the need for autoclaves. Lime precipitation which was widely used in the past is being abandoned as a result of strong evidence showing that calcium arsenate compounds decompose slowly in contact with atmospheric CO2 to form calcium carbonate and soluble arsenic acid. In all cases, the long term stability of the disposed arsenic compounds depends on a number of factors including disposal site characteristics, particle crystallinity and size distribution, the presence of complexing agents and the effect of bacterial activity.

May 1, 2002