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By M. R. Dion, K. Frenette, R. K. Jonas, S. Simard, F. Robichaud

"In 2011, a site study indicated that the application of Honeywell’s Multivariable Predictive Control Technology (MPC) to the Goldex processing facility would provide significant opportunities for improvement. Grinding MPC was implemented in the SAG Mill in June 2015. This pilot application, called Phase 1, featured one of the first Multivariable Predictive Controllers to be installed in a Canadian mineral processing plant. Since the implementation of MPC, gold recovery from the gravity circuit has increased. MPC contributed to a decrease in flotation feed particle size (120 to 112 µm) and an increase in the SAG feed tonnage (8.5% increase). MPC also increased and stabilized the % solids of the SAG feed, which can have an impact on cost reduction (mechanical maintenance). Additionally, MPC increased productivity, providing grinding operators with more time to perform other tasks. Further anticipated benefits include the standardization of the grinding circuit operation from one team to the next, thereby minimizing circuit disturbances resulting from different operating philosophies. This paper will discuss the advanced control project development and justification, the technology and rapid implementation process, the performance results and the benefits obtained.IntroductionGoldex is an underground mine located near Val-d’Or that is owned and operated by Agnico Eagle Mines Limited (AEM). Between 2008 and 2011, mining focused on the Goldex Extension Zone (GEZ). In 2011, the project was halted due to geotechnical problems; operations ceased until late 2013. Goldex operations resumed in September 2013 with the M and E zones, for which there were 0.7M gold ounces of proven and probable reserves, 2.1M ounces of measured and indicated resources and 1.2M ounces of inferred resources, totalizing 4M ounces. Life expectancy was extended until 2024."

Jan 1, 2017

By S. Kelebek, C. Gibson, M. Aghamirian

"Global niobium production is currently dominated by three operating mines, Araxá and Catalão in Brazil, and Niobec in Canada. Although over 90% of the world’s niobium is mined and processed in Brazil, a number of high grade niobium deposits exist worldwide. The advancement of these deposits depends largely on the development of operable beneficiation flowsheets. Pyrochlore, the primary niobium bearing mineral, is typically upgraded by flotation with amine collectors at acidic pH, and often includes a reverse gangue flotation stage prior to pyrochlore flotation. Challenges related to the flotation of niobium ores include complicated flowsheets which require pulp pH adjustment from alkaline to highly acidic conditions, difficulty recovering fine grained pyrochlore, producing concentrates that meet specifications, and minimizing the losses to reverse pre-flotation gangue concentrates, slimes, and tailings. The specific flotation challenges associated with different niobium ores are discussed. In some cases, the use of alternate flotation reagents and flowsheets are required to achieve reasonable gangue rejection and maximize recovery, particularly of very fine pyrochlore grains.INTRODUCTIONNiobium is a transition metal primarily found in the oxide minerals pyrochlore (Ca,Na)2Nb2O6(OH,F) and columbite (Fe,Mn)Nb2O6. After physical upgrading, pyrochlore is converted into a ferroniobium product which is largely used in the production of high strength low-alloy steel. Today’s niobium market is dominated by the Companhia Brasileira de Metalurgia e Mineração, whose Araxá operation produces over 80% of the world’s niobium. There are two smaller operations, Niobec in Canada, and Catalão in Brazil, which account for the remaining production (U.S. Geological Survey, 2013).A number of niobium deposits exist globally, their advancement dependent on the development of operable beneficiation flowsheets. Pyrochlore, the predominant niobium bearing mineral, is commonly upgraded by flotation with cationic amine collectors in acidic pulp conditions. However, many niobium ores do not respond to this typical flowsheet because they are either highly refractory or niobium deports to other minerals such as columbite, ilmenite and rutile, which are not as responsive to this reagent scheme (Bulatovic, 2010). Other reagents, such as alkyl hydroxamic acid, have been studied extensively and while promising, are not without their own inherent issues including lack of selectivity over iron oxide minerals, and high addition rates (Ni & Liu, 2012; Gorlovskii, Eropkiny, Koval, Strelstin, Khobotova, & Shtchukina, 1968; Gorlovskii, Khobatova, & Shtchukina, 1966).It is the aim of this report to highlight the challenges associated with the physical upgrading of niobium minerals through examination of the flotation behavior of two different ore systems. In order to overcome these challenges it is important to thoroughly understand the limitations of typical flowsheets/reagent schemes currently employed in operation."

Jan 1, 2015

By R. D. Lindsay

Pamour Porcupine Mines, Limited has been actively engaged in the ''Custom Tolling'' of Gold-Bearing materials throughout the past decade. Experience acquired in this area was utilized to design and commission a custom gold milling facility at its operations in Timmins, capable of:(a) Accepting a bulk ore test sample at the rate of 150 t/d for crushing, sampling, and metals analysis;(b) Processing gold-bearing ores at a rated capacity of 150 t/d, to produce a goldbearing sulphide concentrate;(c) Processing free milling gold ores at a rated capacity of 80 t/d for total cyanidation;(d) Cyaniding custom gold flotation concentrates at a rated capacity of 80 t/d; and(e) Processing of complex gold/copper or carbonaceous ores, requiring an impurity flotation concentrate separation stage prior to cyanidation, at a rated capacity of 100 t/d.Items considered in the process design and development included:- various gold ore types available for processing;- flowsheet flexibility required;- sampling strategy as related to head grade determination and metals accounting; and- contract considerations.This paper highlights how these various considerations were used to design Pamour's ''Custom Gold Milling Facility''.

Jan 1, 1987

Safe underground mine backfilling with hydraulic fill requires efficient fill drainage and stable fill retaining walls or bulkheads. If any or both the above two requirements are not satisfied, such a backfilling operation creates unsafe conditions and may lead to backfill retaining wall failures. Mine backfill retaining wall failures are always associated with economic losses, fatalities and interruption to mine production. Mining industry wants to either reduce or eliminate these fill retaining wall failures. The fill retaining wall failures could be effectively avoided through the use of fibre reinforced shotcrete fill retaining walls and engineered drainage systems through the retaining walls. This paper presents the experience of the author in developing, implementing, and monitoring several hundred fibre reinforced shotcrete fill retaining walls at a mine in Australia with the highest safety standard. The details on the mine backfill drainage system and fibre reinforced shotcrete fill retaining wall designs are also presented.

May 1, 2007

By Jacob Masliyah, Zhiang Zhou, Tshitende Kasongo, Jianjun Liu, Zhenghe Xu, Jeawon Choung

"Slime coating is a recognized challenge in fine particle flotation, not only in decreasing recovery, but also in reducing the selectivity and hence froth quality. In this presentation, a novel method based on electrophoretic mobility distribution measurement to study slime coatings is described. By measuring electrophoretic mobility distribution of individual minerals and their mixtures, the interactions between these minerals can be evaluated.For illustrative purposes, a model system of fine coals, or oil sands with two different types of fine clays was studied. Flotation tests showed a significant decrease in coal (bitumen) flotation recovery with montmorillonite but not with kaolinite clay addition. When electrophoretic mobility distribution of a fine coal/montmorillonite clay mixture was measured, a single modal zeta potential distribution was obtained, in contrast to a bimodal distribution for fine coalkaolinite clay mixture. This finding suggests a stronger adhesion of montmorillonite than kaolinite clays on fine coal surfaces. In the case of bitumen, the bimodal zeta potential distribution was measured for the mixture of bitumen emulsion and kaolinite or montmorillonite, indicating a weak attraction of the clays by bitumen. In the presence of calcium, however, a single modal zeta potential distribution was obtained in the mixture of bitumen emulsion with montmorillonite but not kaolinite clays. These findings are in excellent agreement with bitumen flotation results, demonstrating that the electrophoretic distribution measurement is a powerful tool to study slime coating phenomenon in a complex fine particle flotation system."

Jan 1, 2002

By Robert Boyd

The Diamond Markets ? Supply has continuously increased over the past 25 years ? However, global supply is expected to drop by 1 to 2% by 2015 ? Demand Driven Market ?Demand is expected to grow 3% annually through to 2015 ? Supply Squeeze Anticipated (2010 to 2015) ? Consumption is exceeding rate of discovery, mine development and reserve replacement ? These fundamentals are driving increased capacity and production at existing mines in South Africa, Botswana and Russia and new areas such as Canada ? Canada is now the third largest diamond producing country in the world ? These fundamentals are also driving record levels of exploration expenditures throughout the world with particular focus on Africa and Canada

May 1, 2006

By Manqiu Xu, Songtao Yang, Zongfu Dai, Robert Pelton

"Hydrophobic polystyrene nanoparticle suspensions were evaluated as potential flotation collectors for pentlandite. Experiments involving both clean model mineral suspensions and complex ultramafic nickel ores confirmed that conventional water-soluble molecular flotation collectors such as xanthate could be partially or completely replaced by hydrophobic nanoparticle flotation collectors. The ability of nanoparticles to induce flotation was demonstrated by floating hydrophilic, negatively charged glass beads with cationic polystyrene nanoparticle collectors. Electrostatic attraction promoted the spontaneous deposition of the nanoparticles on the glass surfaces raising the effective contact angle sufficiently high to promote the adhesion of beads to air bubbles. As little as 10% coverage of the bead surfaces with our most effective nanoparticles could promote high flotation efficiencies, whereas conventional small molecular flotation collector requires ~ 20% or higher coverage for a good recovery. Surface functionalized nanoparticles enhanced the ability for nanoparticle collectors to selectively deposit onto surfaces of the desired mineral particles in the presence of gangue. For example, poly (styrene-co-vinylimidazole) nanoparticles were designed to selectively deposit onto nickel mineral (pentlandite) in the presence of Mg/Si slime. Flotation tests of ultramafic nickel ores at Vale with these nanoparticle collectors have shown improvements in both pentlandite recovery and selectivity. On-going work includes attempts to identify specific applications where nanoparticle flotation collectors might be cost effective.INTRODUCTION Most mineral processing operations include multiple stages of froth flotation to concentrate and isolate the desired product. Before flotation, chemical collectors are routinely added to ground ore slurries, selectively binding to mineral-rich particles, increasing their hydrophobicity thus promoting selective flotation. (Fuerstenau, Jameson, & Yoon, 2007) Conventional collectors are surfactants with a short hydrocarbon tail and a head group, such as xanthate. A typical conventional collector is potassium amyl xanthate (PAX), which is a small molecule with an extended molecular length of about 1 nm. Critical characteristics of a good collector include the ability to selectively adsorb onto desired mineral surfaces and to lower the water/mineral surface energy. Despite the extensive role of flotation in mineral processing, some ores are difficult to process by flotation. For example, ultramafic nickel sulfide ore containing both valuable pentlandite and large quantities of unwanted Mg/Si slime [primarily serpentine, (MgFe)3Si2O5(OH)4] responds poorly to flotation. (Mani, Xu, Quinn, & Stratton-Crawley, 1997) Fibrous hydrophilic Mg/Si slime usually masks the surface of pentlandite (known as “slime coating”) due to electrostatic interaction (Edwards, Kipkie, & Agar, 1980) and dramatically depresses pentlandite flotation. Consequently, new approaches are required for processing these difficult ores."

Jan 1, 2012

By Stuart McTavish

"Noranda's Goldstream mine is a 1,500 ton per day copper-zinc mine located 60 miles north of Revelstoke, B.C.The orebody which contains 3.69% Cu and 2.69% Zn was discovered in 1972. Construction of the mine and mill was completed in 1982 and start up was achieved in May 1983.This paper will describe the flowsheet and related equipment 1n the crusher and mill, in particular the dewatering section where two Larox pressure filters are used to dry the concentrates.INTRODUCTIONThe Goldstrean property is located 60 miles north of Revelstoke, B.C. in the Goldstream River Valley (Figure #1). It was discovered during the construction of a logging road in 1972. Exploratory drilling was initiated in 1975, and in 1976 a portal was collared to obtain underground data. Samples were taken from the underground workings for metallurgical bench tests and a pilot plant run.Due to economic conditions, the decision to go into production was delayed until 1980. Concentrator construction and underground development progressed simultaneously during 1981 and 1982, and were completed by the end of 1982. Start up of the concentrator was achieved on May 2, 1983.The ore typically contains about 40% sulphides, which are chalcopyrite 10%, sphaletite 6%, pyrrhotite 20%, and pyrite less than 5%. The sulphide minerals have a high degree of intergrowth. Most of the sphalerite occurs in micron sized grains which are embedded in the pyrrhotite and, to a lesser degree in the chalcopyrite. There is also some fine dissemination of the chalcopyrite in the pyrrhotite. The waste rock is made up of about 30% quartz, 20% guange silicates, and 10% carbonates. The ore has a specific gravity of 3.2 and a natural pH of 8.2."

Jan 1, 1985

By Vu Van Dong

Resource estimation is the science of determining the amount and quality of a given material in the ground that has the potential to be mined at a profit. This is because during this time computers have become more widely available and more powerful and software packages have become more comprehensive and user friendly. Over the past three years The Mining Geology Company with the support from Vinacomin Group has developed the Coal Geological Modelling and Reserve Estimation ? VMG system. The VMG system enables the geological and mining engineer to start at the reserve estimation for the mine design and planning. The VMG system enables the national and international standards (NI43-101, CIM-Canada; SAMREC Code, Africa, and JORC Code, Australia) and user friendly with menu driven thereby permitting the engineer with minimal computer training to rapidly learn and utilize the system. Geological and mining data input through digitized map files and drill-holes information files stored in the database that is an integral part of the VMG system with the main function for collection, validation, and recording, storing and processing of data will include both ?primary? (observation and measurement) and ?interpreted? data. It is recommend that data be stored digitally, using a documented, standard format and a reliable storage medium that allows for easy and complete retrieval of the data. The coal reserve estimation through standard polygon methods with the increased use of these mathematical techniques (geometrical modelling, geostatistical method, least square method, ?) over the last ten years corresponds, to some degree, to a decrease in both the amount of the coal deposit mapping and, in particular, coal seam structural interpretation and modelling, and permit rapidly evaluation of coal seam and overburden quality and quantity. The understanding of the relationship between the coal mineralization of interest and the likely related complicate geological processes and structure that govern its emplacement and geometry within the geological framework is essential to the establishment of the geological controls for coal mineralization. System outputs includes: drillholes summary reports, stratigraphy, cross-sections, isopach maps, structure, contour maps, premining and post mining topography maps, and 3D perspective view on coal seam structure.

Oct 1, 2009

By G. K. Jorgenson, S. H. Chung

"IntroductionThe SABREX Blast Modelling Program was developed jointly by the companies of the ICI Explosives Group, of which C-I-L Inc. is a member. SABREX (Scientific Approach to Breaking Rock with Explosives) is a modular computer program which incorporates new technology with a number of tested programs that have been in use world wide.SABREX predicts the performance of blasts in terms of (I) fragment size and distribution; (2) muckpile profile and face velocity; (3) grade fracture; (4) collar breakage; (5) a rupture envelope which depicts crack penetration behind and beneath blastholes; and (6) a complete cost analysis including explosives, drilling and accessory costs. The predicted blast results are displayed as dynamic colour graphics and in tabular form.SABREX uses data on the detailed geometry of the drilled and loaded pattern, detonation characteristics of the explosives and the dynamic properties of the rock to generate blast predictions. SABREX blasting calculations take into account the effects that shock and quasi-static pressures exert on the rock around the blastholes. While physical effects occur very rapidly in rock blasting, it is possible to view and model the sequence of events as discrete sections.The program can be run on a microcomputer and is currently operated by C-I-L technical service staff in Canada for the use of drilling and blasting operators.Figure I is a diagram representing the modules of the program and associated technology that is used to complement the program.Any, or all, of the modules may be used in a particular study or blast optimization. Because the BOBCAT module of the SABREX program has been described in previous papers(7.8.9), this discussion will concentrate on the newer modules: CRACK, HEAVE, RUPTURE ENVELOPE and to a limited extent, KUZ-RAM, which present a more detailed picture of the blasting process.Each of these modules is discussed in terms of the information they offer the operator in analyzing the blast. Specific examples of recent usage in Canadian mining situations are included to illustrate the ability of the model to produce practical results that can assist in optimizing actual blasting operations or solving problems that do exist."

Jan 1, 1987

By Ronald L. Bruening

IBC has developed a cost effective MRT process for the selective extraction and recovery of gold, copper, and a mixture of other base metals from mine leach cyanide solutions. This is a two-stage system in which the gold is first recovered selectively as a high purity salt. The copper is then recovered separately as a sulfate salt. The other base metals are then collected as a cyano anion concentrate. Three different SuperLig® materials are used. The first stage can be used alone on gold leach solutions where copper and other base metals are not a problem. The two or three stage system is used when the base metals build up in the leach solution, resulting in increased costs. The cyanide or cyanide/cyano anion concentrate can be recycled back to the leach solution until the build-up of other salts, etc. becomes too high, or this too can be controlled with a percentage bleed stream.

Oct 1, 2003

By Peter Makuvise, Alain M. Bantshi

"The Mazowe Gold Mine is managed by Metallon Gold (Zimbabwe) and is situated in the west-central part of the Harare greenstone belt. Orebodies here generally comprise shear zones which are in-filled with gold-bearing sulphides and quartz. The mineralised zones are up to 1 m in width, have average grades of 4 to 5 g/t, and mostly dip between 10º and 60º to the north.Mazowe Mine is one of the oldest mines in Zimbabwe, and exploration and development in this region dates back to 1890, with over 1.4 million ounces of gold produced to date. Mazowe mine comprises two underground operations, Mazowe and the BSV sections. Ore is processed in a single plant which consists of conventional crushing and milling and carbon-in-leach facility.Baldmin Projects was awarded the contract for the design, construction and commissioning of the 60,000 tonnes per month plant at Mazowe mine in 2014 for the processing of sand and slimes tailings from previous operations at Mazowe mine. The average grade of the tailings is 1.1 g/t. The plant consists of feed preparation, grinding, flotation, thickening of flotation concentrate, and carbon in leach (CIL). A pump station for hydraulic mining of the slimes tailings dam also part of the plant.Key features of the Mazowe sands Plant are described and include:• Hydraulic mining of gold tailings dump.• Feed preparation section that includes a (W x L) 2.4 m wide x 4.8 m trash screen, 250 m3 surge tank, a cluster cyclones with 2 x 500 mm diam. Cyclone.• Comminution circuit designed for a bond work index range of 10-12 kwh/tonne. comminution circuit is constituted with 3 ball mills, 1.83 m diam. X 6.71 m Long, 280 kW.• Flotation circuit comprising rougher bank, scavenger bank and cleaner bank. Rougher Scavenger bank is constituted of 6 x 6m3 flotation cells and 3 x 30 m3 flotation cells and the cleaner is constituted of 3 x 6 m3 flotation cells.• Concentrate Thickening with 6 m diam. Thickener.• Concentrate CIL (carbon in leaching): CIL circuit is comprised of 7 tanks with 2 leach tanks and 5 Carbon in leach."

Jan 1, 2017

By Constantin D. Pitis

Similarly to notions of constant capital/expenses in business or magnetization power for electric motors an energetic base load (E0) is always necessary to set up a mining process. Denominated as ?non-productive energy? or base load, (E0) is a constant component of the entire energy consumption of the process, while another component the ?productive energy? (Ep) is variable, being function of the production/throughput (M). By using these new concepts, the author creates an energetic model proposing a new method of assessing changes in mining processes (throughput) that can reveal possible energy savings (DSM component) or energy losses. Proposed mathematical model of assessing (E0) and energy savings by using ?Marginal Energy Usage Index? (MEUI) enables creation of historical benchmarks and direct on line energetic (efficiency) assessment of mining processes and/or equipments. The paper analyses the case of assessing possible energy savings that can be obtained by: ?? Improving efficiencies of various equipments (by retrofit) ? reducing E0 ?? Improving the process control or other process changes ? reducing Ep ?? Monitoring persistence of the adopted Energy Conservation Measures (ECMs). For the new plant design, the proposed method enables prediction of Customer Baseline in various mine/process configurations. The method could become part of a ?preventive action? in design process by offering a reliable tool of assessing additional financial effort (Incremental cost) when choosing various higher efficiency equipments and/or processes.

Oct 1, 2009

By Martin Nevens

"In 1998, the Iron Ore Company of Canada initiated an aggressive program to improve the performance of its Carol Lake Concentrator located in Labrador City, Newfoundland. This program was termed the Concentrator Upgrade Program. The Concentrator Upgrade Program was a group of initiatives developed with the common goal of improving the overall process and operations of the IOCC Carol Lake Concentrator. The main goal of the program was to increase the annual production capacity of the concentrator from 18.0 million tomes to 21.6 million tomes. This gain in capacity was to be done mainly through improvements in process iron recovery. The target iron recovery value was 80+% versus a historical value of 70%. This improvement in iron recovery would translate to a natural weight recovery improvement from 44% to 50%.The Concentrator Upgrade Program provided the first opportunity in 30 years to make fimdamental changes to the concentrator flowsheet. To accomplish this, several pilot plants were built to evaluate new circuits. AAer 2 years, a new flowsheet was selected for the primary gravity separation circuit and the magnetite circuit. The centrepiece of the new flowsheet was the introduction of Hindered Settling Separators to the metallurgical process.The Concentrator Upgrade Program has since proceeded into detailed engineering and, as of February 2001, construction. The first one of IOCC’s 3 primary AG Mills (Mill 11) has been converted to the new flowsheet at the time of writing and is in the throes of commissioning. This paper will review the flowsheet development program in the pilot plant for the gravity separation circuit and examine the overall benefits to the operation of the IOCC Carol Lake Concentrator."

Jan 1, 2002

By S. Nikolic, G. M. Stieper, D. P. Mallah, B. J. Hogg, P. B. Voigt

Copper feed materials processing is becoming more challenging, due to an incremental increase in the mineralogical and compositional complexity of these feeds. These complex and polymetallic feeds are now becoming more common and many sites have been forced to re-evaluate their operating strategies to process these materials at cost competitive rates, whilst meeting ever more stringent environmental regulations. Most operations must first evaluate the merits of pyrometallurgical and hydrometallurgical treatment routes. Although there are multiple copper smelting technologies available, only top-submerged lance (TSL) technology, supplied by Glencore Technology as ISASMELT™, has been applied in the real world to consistently and successfully smelt complex materials in integrated metallurgical facilities such as Glencore’s Kazzinc Ltd. operation in Kazakhstan, Umicore Precious Metals Refining in Belgium and Aurubis AG in Germany. Glencore Technology also offers hydrometallurgical processing, through the Albion Process™ technology, opening up viable flowsheet options previously not possible for these complex feeds. This paper describes a number of real world process flowsheets at global operations and Glencore’s own operations at Mount Isa and Kazzinc Ltd., which process complex feeds. These flowsheets integrate the ISASMELT™, Albion Process™, ISACONVERT™, ISAKIDD™ Tank house, and bottom blown oxygen cupel (BBOC™) technologies to provide an effective process solution for the treatment of complex polymetallic feeds to produce metallic copper and associated by-products. INTRODUCTION Traditional smelters and those built in recent times within the bulk smelting hubs of the world have been designed to treat standard/clean concentrates. In recent years the processing of complex polymetallic sulfide concentrates and the recycling of secondary copper and derivatives of waste electrical and electronic equipment, such as e-scrap, have become a focus for numerous companies (Alvear & Nikolic, 2013). Processing of these complex feeds, characterized by relatively high levels of minor elements (over 5% of elements such as arsenic, antimony, bismuth, lead and zinc) is more challenging. Facilities not designed for these types of materials may require significant modifications or a change in smelting technology to treat them. Often operations find themselves re-evaluating the merits of pyrometallurgical and hydrometallurgical treatment routes for their sites through a number of factors:

Jan 1, 2019

By L. Flett, S. Woods, C. Deredin

"Following a significant reduction in world Imperial Smelting Furnace (ISF) capacity from 2003 to 2008, a major optimization initiative was successfully carried out on the lead upgrading and bulk (zinclead) flotation circuits in the Brunswick Concentrator.This paper describes the process improvements that have taken place in order to reduce the quantity of bulk concentrate:•,Increase in lead upgrading rougher flotation circuit capacity•,Installation of a closed-circuit bulk regrind utilizing MillPebs and 150 mm Cavex hydrocyclones•,Installation of two additional cleaner flotation stages on the bulk circuit•,Optimization of the manipulated variables in the lead upgrading and bulk circuitsINTRODUCTIONThe Brunswick Mine (Xstrata Zinc Canada) is located near Bathurst, New Brunswick and is one of the world’s largest lead/zinc mines. Milling of ore commenced in 1964 from the No. 12 orebody, with an expansion in 1966 to accommodate ore from the No. 6 open pit mine. The planned closure of the mine will take place at the end of the first quarter in 2013. The ore is a complex massive sulphide, consisting of approximately 20% valuable minerals, 60% pyrite and 20% silicates.A simplified flowsheet for the concentrator is given in Figure 1. The overall flowsheet involves SAG milling, secondary ball milling, selective flotation, and dewatering by thickening, filtering and drying. The complexity of the flowsheet evolves from the requirements for fine grinding and the production of four concentrates: zinc (sphalerite), lead (galena), copper (chalcopyrite) and bulk (sphalerite plus galena).Primary hydrocyclone overflow feeds the copper-lead aerator-roughers for flotation at pH 9.0 with soda ash. Plant xanthate (80-20 sodium isopropyl and potassium amyl) and AP407 are used as collectors in the copper-lead circuit. The rougher concentrate is directed to the copper-lead regrind circuit and the tailings are fed to the secondary grinding circuit. The secondary hydrocyclone overflow from the secondary grinding circuit feeds the copper-lead rougher-scavenger banks. Rougher concentrates are reground to a P80 of 28 µm prior to three stages of copper-lead cleaning. The first stage of cleaning is done in an open circuit with the tail reporting to the cleaner scavenger. The cleaner scavenger concentrate reports to the regrind circuit and the cleaner scavenger tail combines with the rougher/scavenger tail to feed the zinc circuit. The second and third stages of cleaning are performed in closed circuit with the cleaner tail being recycled to the copper-lead regrind circuit. The average final concentrate grades 23% Pb, 3% Cu and 704 g/t Ag, and is fed to the copper separation circuit."

Jan 1, 2013

By D. Imeson, T. Grammatikopoulos, M. Aghamirian, M. Oliazadeh

"More than 70% of potash is produced worldwide by froth flotation. Flotation of potash was developed in the early 1930s. Amines are widely used for flotation of sylvite (KCl) from halite (NaCl) and insoluble materials such as clays. Amine collector is also absorbed by clays. Therefore, clays are usually separated by scrubbing and de-sliming prior to flotation. Alternatively, slimes can be floated ahead of potash flotation. Flotation recoveries of sylvite are commonly in the range of 85%, while losses can occur in slimes, flotation tailings and make-up of process brine. Ores containing free coarse-grained sylvite are generally screened, whereas both fine and coarse fractions are conditioned and floated separately. The unique features of potash flotation include solubility of sylvite in water, the size of particles floated and fast kinetics. Particles up to 2.3 mm can be floated and about 50% of flotation feed can be removed in the rougher stage in few minutes. The main challenges in potash flotation are the recovery of potash from slimes, flotation efficiency in the presence of carnallite and recovery of coarse potash grains. A review of potash flotation shows that there is still room for improvement in both coarse and fine potash flotation. The present paper reviews the most significant flotation parameters including reagent type and dosage, flotation circuits, flotation equipment size and new developments in potash flotation. The latter include new reagents, flotation technologies (Hydrofloat, Jameson and column cells) larger flotation cells and slimes flotation.INTRODUCTION Potash is the common industrial term for potassium in various chemical combinations and minerals soluble in water. About 90% of potash produced worldwide is used as agricultural fertilizers. Flotation is the main treatment process of sylvinite (KCl-NaCl) ores for recovery of sylvite (KCl). Potash concentrate should contain a minimum of 95% KCl and be relatively free from 0.2 mm KCl fines. The flotation process for beneficiation of potash ores was developed in United States and Russia concurrently in the early 1930s. In 1934, Potash Corporation of America applied flotation process in a commercial scale (Tippin R.B. and Huiatt J.L). In the initial application, halite (NaCl) was selectively floated by employing lead chloride as an activator and soap as collector. The sylvite concentrate was reported in the cell underflow."

Jan 1, 2012

By Chuck Edwards

"Milling operations in northern Saskatchewan’s Athabasca Basin have produced uranium continuously since 1975. Over that period, the Athabasca Basin has been one of the world’s premier uranium camps, yielding more than 660 million lb of U3O8. In this paper, the author describes former and current milling operations and discusses why and how the milling process has changed and developed over the past 35 years. The author’s considerations for the future of uranium extraction in the Athabasca Basin close out the paper.INTRODUCTIONThe roughly oval Athabasca Basin in northern Saskatchewan occupies nearly one third of the surface area of the Saskatchewan Shield. Its sandstone-like deposits lie unconformably on the older basement. The basin hosts many high-grade unconformity-type uranium deposits(Saskatchewan Energy and Resources, 2010) for which the Athabasca Basin is world famous. Uranium production in the Athabasca Basin has come from four mills. In the order of startup these are Rabbit Lake, Cluff Lake, Key Lake and McClean Lake. General data (AREVA, 2010; Cameco, 2010; Denison 2010) for each mill are shown in Table 1."

Jan 1, 2011

? Founded In 1953 ? Mining growth of 83% since 2007 ? We produced over 1 million ounces of Au in 2012 ? We Forecast of 20% Au production in 2013-2015 ? We have paid a dividend 31 years consecutively. Terry Reid ? 1992-93 Electrical Technical, College ? 1994-95 On the job placement College ? 1998 ? Licensed Millwright, ? 2005-12 ? Maintenance Reliability Planner ? 2012- Present Business Process Owner

Aug 1, 2013

By Peter White

Mine Planning Shaft Collar Shaft Sinking Raises Ramp Underground Water Storage

May 1, 2009