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By G. Hamel

The LCL&L process (Low Caustic Leaching & Liming) is a patented hydrometallurgical route developed by Rio Tinto Alcan (RTA) to economically process spent pot lining (SPL) generated by aluminum cells. The three resulting end-products (carbonaceous, fluorinated and caustic liquor) are inert and have valorization possibilities. An industrial size pilot plant located in Saguenay (Quebec) was inaugurated in mid-2008 to demonstrate and optimize the technology. This paper describes characteristics of the LCL&L process and the experience acquired by RTA since the plant's start-up, including ramp-up capacity and technology challenges that were overcome. Possible end-products valorization methods are also presented. The carbonaceous end-product can be separated into carbon and brick rich fractions and used as either alternative fuel, reducing agents, or as raw material for third party processes. The development of a conversion process for the fluorinated end-product would allow its reuse as a substitute to fluorspar mineral for aluminum fluoride production. Finally concentrated caustic liquor is already valorized at the nearby RTA Vaudreuil alumina refinery.

Jan 1, 2011

By M. Sagedahl

The off gas from a smelter is cooled and dust removed in an electrostatic precipitator before approximately 95% of the sulphur dioxide (S02) is converted to sulfuric acid. However, the tail gas may need to be polished to remove the rest S02 to meet demands. A flue gas desulphurization (FGD) system, as usually applied to S02 removal on coal and oil fired Power Station, is suitable for polishing tail gases from copper smelters. The ALSTOM Seawater FGD process makes use of the alkalinity in the seawater to absorb and neutralize S02. Before being returned to the sea, the seawater is treated to comply with environmental regulations. As the ALSTOM Seawater FGD process uses no reagent and produces no byproduct, it is extremely cost-effective for coastal installations. The first SWFGD plant started operation in 1968. Over 60 of these units have been installed worldwide. The ALSTOM Seawater FGD process removes S02 from flue gas flows corresponding to a total of 70,000,000 Nm3 /h. Suitable for thermal power stations, smelters and oil refineries, ALSTOM Seawater FGD plants efficiently treats flue gases in the range of 300,000 Nm3/h to 2, 700,000 Nm3 /h per FGD plant, containing 20 - 6,500 ppm of S02.

Jan 1, 2007

By B. Tiryaki, M. Ayhan, O. Z. Hekimoglu

Coal shearers are one of the major sources of dust and fines in underground coal mines. Despite considerable research investigations, no comprehensive in situ investigations coupled with extensive laboratory studies on the effects of drum design on generation of dust and fines have been found. It may be for this reason that many major shearer drum manufacturers persistently employ a certain drum-lacing pattern on current coal shearers, which is believed to cause excessive dust and fines in coal mines. This paper shows how respirable dust and fines are minimized under near-identical conditions when the drum lacing pattern was changed from a triple-tracking to a single tracking arrangement. A series of laboratory trials simulating in full scale the practical cutting action of tools was followed by extensive long-term underground trials during production operations in OAL (Cayirhan) Lignite mine in Turkey. The results are presented and discussed, and recommendations for proper drum-lacing in terms of respirable dust and fines are made.

Jan 1, 2002

By C. V. Corless

1. Introductory Some members may recall that at the Annual Meeting two years ago I read a paper, 'The Future of the Mining Industry in Canada." Discussing this large subject it was possible only to outline the facts and inferences leading to ?the conclusion that Canada is a country endowed with enormous mineral wealth, of which the fringes are yet scarcely touched. In the present paper, I wish to examine in somewhat fuller detail the evidence, both direct and inferential, concerning the mineral wealth of the greatest physical and geological feature of Canada-the Precambrian Shield. Many, if not most, of these facts are already familiar to you. But, since they will form the basis of the reasoning employed, they will be recalled for explicit reference. First, let us review very briefly the position and extent of the Shield. The area of the entire Shield is given in textbooks as 2,000,000 square miles, of which perhaps 10 or 12 per cent. is exposed in the south-easterly part of Canada's Arctic islands. The remainder occupies roughly two-thirds of the North-west Territory; the north-east corner of Alberta; one-third of Saskatchewan ;two-thirds of Manitoba; three-fourths of Ontario; and nearly ninety-five per cent. of Quebec.

Jan 1, 1924

By W. S. Tremaine

When the Hedley Mascot mill was built in 1935, it was designed as a straight flotation plant. The ore to be treated at that time was a gold ore in which the gold was intimately associated with arsenopyrite and pyrrhotite in highly silicified and garnetized limestone gangue. This material was ground to 85 per cent minus 325 mesh in two-stage grinding and floated in standard flotation cells to produce about a 5-ounce concentrate, which was shipped to Tacoma smelter for refining. This arrangement gave us a recovery of about 89 per cent. Test work indicated that the best way to improve this recovery would be to build a cyanide plant to treat our flotation middling. Arrangements for the construction of this plant were finally approved and work on it was started in the spring of 1940. This plant was of the conventional type in which the flotation middlings were thickened, filtered, and then put through the usual cyanide process. Its capacity was 50 tons of middlings per day. This arrangement worked quite satisfactorily and gave us an increase in overall recovery of 4 per cent. Unfortunately, about the time the plant was completed, we developed, and started to ship to the mill, ore that differed entirely from that met with up to that time. Instead of being hard, it was very soft, the orebody from which- it came being much faulted and brecciated. In many sections, the sulphides were oxidized and the breccia was filled in with a very soft, hydrous iron silicate known as chloropal. When this new ore was mixed with the old ore and sent to the mill, the whole operation was disrupted. The chloropal slimed so badly that the classification, flotation circuits, and cyanide plant would not handle it. The difficulty in the cyanide plant was at the head end, where the 10 ft. by 20 ft. thickener and the 8 ft. by 8ft. drum filter would not handle the middlings containing a large percentage of primary slime and chloropal. This material would not thicken to more than 30 per cent solids in the thickener and, when pumped to the filter, would forma very thin, slimy cake. Overall recovery dropped to between 83 and 84 percent and it was quite apparent that some extensive changes would have to be made in our flow-sheet before this ore could be treated successfully.

Jan 1, 1947

Mirador - Overview ? Located in Andean foothills of SE Ecuador ? Copper-gold porphyry hosted by calc-alkaline Late Jurassic granitic and porphyritic rocks ? 438 MT of 0.61% Cu and 0.19 g/t Au measured and indicated resources (at 0.4% Cu cut-off) ? Additional inferred resources of 235 MT of 0.52% Cu and 0.17 g/t Au ? Initial 25,000 tonnes/day production, expanding to 50,000 in year 6 320 MT of 0.62% Cu, 0.2 g/t Au ore mined at an average 1.4:1 strip ratio over a 21 year mine-life

May 1, 2006

By J. A. Bos, Z. Dai, P. Quinn, A. Lee

A flowsheet is being developed for processing Thompson ultramafic low-grade nickel ores. This type of ore is characterized by high content of serpentinized magnesium silicates which generate slimes during comminution. Flotation of this type of ore proves difficult due to problems associated with the slimes. The flowsheet, based on extensive laboratory and miniplant flotation tests, consists of two key components: desliming by hydrocyclones prior to flotation and using soda ash for pH control in flotation. Satisfactory metallurgical results have consistently been achieved in laboratory full circuit simulation and miniplant tests.

Jan 1, 2009

By Wei Wang

The SMCO copper plant is located in DR Congo, and was designed by China NERIN Engineering Co., Ltd. The process is a typical hydrometallurgical plant with Leach-SX-EW, with the project treating the oxide minerals with agitation leaching, followed with three stage of solvent extraction and two stages of stripping, and using permanent SS cathodes to produce LME grade copper. Because of the special characteristic of the ore, what contains 2 different type of oxides (one high carbonate oxide and the other low carbonate), there are several new technical measures that have been developed and adopted for the plant. For example, different grinding, leaching, and filtering are used to treat different oxides. This paper, presents the project process, engineering design, construction and commissioning. The paper also describes some of the problems encountered during plant commissioning, such as the agitation leaching tank issues, and corrosion in the settler-mixer. This paper discusses some NERIN solutions to these problems, and explains the use of the CN filter, which is used to filter PLS to treat high level suspend solids, instead of the traditional sand filter. Finally, this paper also proposes steps / measures for further improvement for future plant operation.

Jan 1, 2014

By S. S. Dimov, B. R. Hare

This paper describes two micro-beam analytical techniques(Dynamic SIMS and TOF-SIMS) which have become an intricate part of a comprehensive analytical approach for precious metal (PM) ore characterization and process mineralogy or deportment studies. The value of the D-SIMS technique is its capacity for accurate analysis in the sub ppm range along with the ability to produce high resolution elemental maps. The TOF-SIMS is significant for speciating and quantifying preg-robbed Au on the surface of carbonaceous material. In combination with traditional assays, the two techniques can provide invaluable information regarding the distribution of PMs within an ore along with providing insight into potential sources of PM loss in processing or where losses have occurred in process streams.

Jan 1, 2011

By F. Tanaka

Copper losses to discard slag have long impacted on the profitability of copper smelters. Businesses based on the treatment of secondary materials have also revealed that copper losses are indices of precious-metals losses. Many custom smelters are thus required to obtain more reliable controls for reducing copper losses than ever before. Mitsubishi Materials Corp. has cooperated with academic research institutes in conducting research projects on the pyrometallurgical fundamentals of copper smelting systems, including mutual evaluation of magnetite behavior between synthetic and industrial slags. The state-of-the-art pyrometallurgy has subsequently been introduced to Naoshima smelter for controlling the Mitsubishi process. The revised controls function successfully and the operational results demonstrate that avoiding the discharge of solid magnetite from the S-furnace is quite effective to reduce copper losses. Magnetite behavior has been controlled over the Mitsubishi process so as to reduce copper losses while satisfying the needs of recycling businesses growing in Japan. In-situ estimation of magnetite behavior using the absorbed heat from the melts to cooling water will also be discussed.

Jan 1, 2007

By P. Mišcevic, B. Kavur, I. Vrkljan, N. Štambuk Cvitanovic

It is known from earlier and recent research that mechanical properties of intact rock like uniaxial compressive strength (UCS), Young's modulus (E) and Poisson's ratio (?) are influenced by shape deviations of test specimens as deviations from the ideal cylinder. That impact can be significant at certain level of inaccuracy of specimen preparing, and it should be objectively evaluated and controlled in testing. The effects of intact specimens side straightness, ends flatness, ends parallelism and perpendicularity to the specimen axis, on UCS, E, and ?, measured in several actual ways during laboratory compression tests, were determined by previous research on 90 homogeneous specimens of limestone. In this paper, we subject these new experimental results to Response Surface Methodology (RSM) to model the mentioned dependence, to identify significant connections of variables and to evaluate the conclusions obtained directly from experimental phase. This study indicates how the responses of the model (outputs) – parameters UCS/E/??of limestone rock depend on factors (inputs) – parameters of specimen shape deviations like flatness R, parallelism P and perpendicularity O, assuming modern test machines with spherically seated upper platen. Starting from general RSM model with three factors (R, P, and O), we investigated the multiple linear regression models of specific mechanical property (UCS, E, and ?). Using the NCSS program ("NCSS 2004 and PASS 2005") in several steps, final models with very high coefficients of determination were developed for properties with the most evident effects of specimen shape deviations: nine models for strength UCS and UCS50 (equivalent UCS for specimen with 50 mm diameter), and three models for ?L (Poisson's ratio calculated from axial deformations measured on the entire specimen length). These statistical models with their response surfaces further strengthen and confirm the results and conclusions from the experimental phase. The critical values of R, P, and O are established using an additional statistical analysis to determine the lower and upper engineering limits. These findings set the basis for the new eligibility criteria for specimens of limestone (and similar rock with UCS about 100-150 MPa) in further testing of strength and deformability.

Jan 1, 2015

By V. I. Ryaboy, V. P. Kretov, I. V. Ryaboy, E. D. Shepeta

This paper studies the features of known and newly synthesized dialkyldithiophosphates and reagents with thioamide groups when separating copper-containing and arsenic-containing minerals in the flotation of skarn-scheelite-sulphide ore at the Primorskaya concentration plant. The optimization of dialkyldithiophosphate collectors was based on the study of their surface activity at the liquid-gas interface and estimated hydrophobic abilities. The flotation experiments show that the selectivity of action of the reagent increases with an increase of its surface activity and a reduction of hydrophobic ability when separating chalcopyrite and arsenopyrite. IMA-225-5 was proposed as a more efficient dialkyldithiophosphate collector, which increases the recovery of copper by 2.8% compared to the industrially used collector IMA-I413. Selection of the optimal structure for reagents with thioamide groups (derivatives of thionocarbamate and thiourea) was carried out according to their acidity and the presence of hydrophilic particles in their structure. Calculations were performed depending on the pH of the solution of chalcopyrite to determine the optimum reagent sorption and to further optimize the structures of these reagents. The tests with reagents with thioamide groups show an increase in copper recovery by 3-4% together with a significant increase of arsenic content compared to IMA-225-5. As a stronger collector with thioamide groups, it was recommended to use sample 234, which belongs to the thiourea derivatives. IMA-225-5 was recommended for industrial tests at the Primorskaya concentration plant. Thus, this study has shown that using dialkyldithiophosphate is more appropriate if it is necessary to increase the selectivity of separation of copper-containing and arsenic-containing minerals, and using reagents with thioamide groups, or their combinations with dialkyldithiophosphates, is more appropriate if it is necessary to increase the recovery of copper or the quality of copper concentrate with less selectivity of the process.

Jan 1, 2016

By T. Guan, G. Fu, X. Zhou, L. Deng

"Currently, tailings water is required to be recycled in minerals processing plants. When the flotation tailings water of complex copper-sulfur-tungsten polymetallic ore is reused to the flotation of copper-sulfur ore, a portion of tungsten would be lost in copper concentrate or sulfur concentrate due to the addition of the collectors used for oxidized ore which are also effective for the sulfide minerals in the process of tungsten flotation. At the same time, the technical index of copper concentrate and sulfur concentrate would be seriously affected by tailings water. Our experimental researches of many years show that the copper concentrate with a grade of 18.36% Cu at a recovery of 76.67% is obtained for the raw ore containing 0.60% Cu, 18.99% S, 0.16% WO3 in small locked cycle test using recycled water, through simple pretreatment of the tailings water from tungsten flotation and adding special regulator CW and new tungsten collector TM. The result is close to the performance without using tailings water. And, in the continuous pilot experiment which was continuously conducted for 4 days with the same technology, the following results was obtained: the copper concentrate with a grade of 21.74% Cu, the recovery was 71.55%; the sulfur concentrate with a grade of 45.16% S, the recovery was 80.10%; the tungsten concentrate with a grade of 42.63% WO3, the recovery was 54.62% relative to raw ore (the recovery relative to scheelite was 76.47%). The throughput of the continuous pilot experiment is 1.0~1.2 t/d, and the raw ore contains 0.56% Cu, 18.80% S, 0.14% WO3 on average.INTRODUCTIONMining industry is one of the most important developing fields, it supplies raw materials for industrial production as well as discharges much waste water. Tailings water is the main source of beneficiation waste water, it would result in severe environmental pollution if discharged directly. Generally, the tailings water would bring undesirable effect on flotation index after simple pretreatment by lime (Kalin, Fyson, & Wheeler, 2006). On the other hand, the treatment of tailings water through ion-exchange (Cui & Liu, 2015) before recycling is of high cost. Generally, in the flotation of Cu-S-W polymetallic ore, when the tailings water from tungsten flotation is treated simply by lime and recycled to the flotation of sulfide minerals, the flotation index of sulfide minerals decreases, and a portion of oxide mineral would be lost in the sulfide concentrate. As a result, the recycle rate of this kind of tailings water is relatively low, some of the tailings water is discharged after simple treatment and then environmental pollution is caused subsequently. One of the effective ways to improve beneficiation performance and increase the recycle rate of tailings water is to conduct research on developing recycle technology for flotation tailings water of complex copper-sulfur-tungsten polymetallic ore."

Jan 1, 2016

By R. Harrisson, K. Esmaieli

Brunswick mine employs an ore and waste pass system for material transfer. This paper reviews the evolution and performance of ore pass systems at the mine. It presents the range of selected configurations, inclination, dimensions, etc. Select case studies are used to address the influence of structure, stress and materials handling on the longevity of the employed ore passes.

Jan 1, 2008

By Alan A. Barton

Introduction The Little Long Lac mine is situated in the Thunder Bay mining district, township of Errington, Ontario. The mine is located on the south side of the most westerly bay of Little Long Lac. The property consists of 36 claims, which comprise some 1,400 acres. This group of claims was staked in August, 1932, by Tony Oklend and Tom Johnson, and, after surface sampling, was optioned by the present controlling interests, who diamond-drilled it during the winter of 1932-33. In early spring, a small steam-driven plant was installed, and shaft sinking commenced on June 1st, 1933. During the summer, all supplies are transported to the mine from Hardrock station, at mileage 18 on the Canadian National Railway line from Longlac to Port Arthur. At Hardrock, which is seven miles from the mine, the railway skirts a bay of Little Long Lac, and supplies are loaded directly from railway cars to scows. Two scows are used, of 30-and 45-ton capacity, respectively. A 36-ft. pointer, powered by a 35 h.p. engine, is used as a tug. A good winter-road has been cut out from Geraldton to the mine, for winter transportation. Geraldton is about two miles north of the mine, and is also located on the Canadian National railway. A hard-surface road is now being constructed for summer as well as winter use. Geology The Little Long Lac gold area covers the northern limits of a large synclinal structure, the contact of the Keewatin flows and sediments, striking about twenty degrees north of west, with the dip of the sediments varying from eighty degrees north to seventy degrees south, the average being around eighty degrees south. The vein worked by Little Long Lac Gold Mines occurs in massive sedimentary rock of about the composition of arkosic or quartzitic greywacke, and consists of a shear-zone up to fifteen feet in width, striking N.75°E. and dipping steeply to the south, which has been filled by numerous narrow, parallel quartz veins and. veinlets. These are well mineralized. with arsenopyrite, pyrite, and some chalcopyrite and stibnite, and carry considerable quantities of visible gold. They show more than one age of quartz deposition, the quartz being fractured and re-cemented. The arkosic rocks separating the veins and veinlets are also slightly mineralized with pyrite. Work to date has indicated the probability that the vein-shear is controlled by local drag-folding.

Jan 1, 1935

By Jerry Ran

Many large underground mines using the open stoping method have changed their primary applications of consolidated rock fill (CRF) to paste or consolidated hydraulic fill due to considerations of demand in infrastructure and equipment, system reliability, backfill capacity and material sources. However, some smaller or even large mines still use or consider using CRF for backfill purpose due to factors such as capital expenditure, availability or suitability of other fill types or in some cases local regulatory requirements. As demands on CRF applications diminish among major mining companies, there is a lack of recent literature on application of CRF to open stoping in design and operation. There are several methods being used for fill strength design. Results from these methods have been successfully applied to paste or hydraulic fill. However, the design strength for CRF is much higher than that determined by use of these widely accepted methods. In operation, CRF preparation and placement have significant impacts on the quality of placed CRF and therefore the mining performance. This paper reviews the current fill design methods and their applications to open stoping with presentation of the bench marking data, presents fill failure cases and various CRF preparation and placement arrangements and discusses quality assurance and control programs.

Jun 1, 2012

By Robin Sheremeta

Fording Greenhills first acquired GPS (Global Positioning System) technology with the commissioning of a GPS-based dispatch system in December 1994. The second exposure to satellite technology came with the conversion of the conventional optical survey system to a high-resolution GPS system in June 1995. In September 1995,a GPS-based grade control system was tested on the largest shovel (Marion 301 — 58 cubic yard).In January 1996, the system was added to all of the cable shovels (2 P&H 2800s). All three applications of GPS at Greenhills are fully operational and producing positive results. This paper will focus on the practical application of GPS in a mining environment and the effect that GPS technology has had on the Greenhills Mine.

Jan 1, 1996

IN 1932, the No. 4 shaft at Wright-Hargreaves mine was completed to a depth of 4,000 feet, and the lowest operating level at that time was at 3,900 feet. It was realized that the existing pumping system, using triplex plunger pumps at somewhat irregular depths in the mine, would be in-adequate to take care of the increasing volume of water that would have to be handled as mining operations expanded. Accordingly, in February, 1932, after a thorough study of the whole matter, it was decided to instal an entirely new, automatically controlled, system of pumping, employing centrifugal pumps, with their characteristically trouble-free performance, operated by off-peak power.

Jan 1, 1939

Surfaces forces have been measured between gold sphere and gold-coated glass plate in xanthate solutions using an atomic force microscope (AFM). The measurements conducted in potassium amyl xanthate (PAX) and potassium ethyl xanthate (KEX) solutions showed long-range hydrophobic forces, with the force curves showing no evidence for nanonubbles on the surface. The strongest hydrophobic force was measured at contact angle of 94° with a decay length of 23 nm. The hydrophobic force became weaker at higher concentrations and after a long immersion time, which may be attributed to the xanthate species adsorbed on top of the first mono layer. The hydrophobic force became stronger when the residual xanthate solution is displaced by pure water, indicating that hydrophobic force becomes the strongest in pure water.

Jan 1, 2009

By Mark Weidenbach

OZ Minerals owns and operates the Prominent Hill copper-gold concentrator in South Australia, built in 2008 and commissioned in early 2009. The concentrator operates via semi autogenous grinding in a thirty four foot ThyssenKrupp Polysius mill followed by a twenty four foot Polysius ball mill in closed circuit with hydro cyclones, designed for an ore throughput of eight million tonnes per annum. The main aspects of designing the circuit are discussed along with the issues faced in the early stages of operation. A review of the optimization strategy applied to the milling circuit such as cyclone optimization, advanced process control strategy implementation and reline management to improve availability is then discussed highlighting areas of significant process improvement that have seen the plant exceed nameplate throughputs above nine million tonnes per annum.

Jan 1, 2012