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By E. J. Marcotte

"IntroductionDevelopments in the preparation, hydraulic transportation and placement of classified mill tailing as an effective backfill and support for mining excavations, have made feasible several advancements in mining methods that are safer and more economical. Hydraulic backfill systems have played an integral part in the development of more efficient cut-and-fill and blasthole stoping.The hydraulic transportation of tailing fill has made possible the elimination of expensive and laborious transportation, placement and spreading of gravel type fills. Also, in cut-andfill stopes, the use of hydraulically placed consolidated fill has largely eliminated the need to use extensive timbering for floors and supports, previously necessary when only gravel type, waste rock or unconsolidated tailing fill was used .Another important advantage of using mill tailing as backfill is that it decreases the need to contain a large portion of the mill solids waste in a surface disposal area and thus reduces environmental and ecological problems.Tailing Fill PropertiesConsolidated tailing fill consists of deslimed mill tailing and Portland cement. These two materials are mixed together in various proportions to form a high density slurry which is transferred underground by gravity through boreholes and pipelines. After placement underground, the water is drained off and the mixture is allowed to set. The strength of the consolidated fill is dependent on the cement content, particle size distribution and curing time. A typical tailing/ cement ratio used for bulk filling in stopes requiring vertical wall support is 30:1. Ratios ranging from 8:1 to 5: 1 are used for stope floors. High pulp densities minimize segregation and loss of cement during placement as well as reduce the amount of drainage water to be handled."

Jan 1, 1989

By A. C. Halferdahl

The Granby ores may be divided into three groups or classes. The No. I ore is a heavy pyrite, chalcopyrite, pyrrhotite, sulphide carrying some free silica, and calcite. No. 2 ore carries the same general group of sulphides as does No. 1, but in a lesser amount. The gangue is an altered greenstone. No. 3 ore has a smaller amount of sulphides than either of the others. Analyses of these ores is as follows: Cu. Si02 Fe. CaO S. Al 203 MgO No. I. Per Cent. 1.8 17.5 33.0 5.7 34.5 2.3 1.3 No. 2 Per cent. 2. 0 35. 6 23. 9 4. 3 I .5. 0 9. 2 6 .. 0 No. 3, Per cent. 1 . 5 40. 9 21 . 7 3. 0 I 1 . 3 11 . 0 5 . 4 The sulphide minerals in No. 2 and No. 3 ores occur largely in bands in the gangue, and for these portions comparatively coarse grinding serves to release the gangue. Drill cores show a certain dissemination of sulphides in portions of the rock, so that grinding to 5 per cent. + 65 mesh with 65 per cent.-200 mesh liberates the sulphide minerals very completely. The association of the sulphides is fundamental. The pyrite was probably deposited first and was followed by a portion of the chalcopyrite, or these two portions of the sulphide minerals were deposited together.

Jan 1, 1924

By J. M. Cormie

"The orebodies of the East Malarcic mine are interesting from a geological standpoint because of the very small amount of vein quartz, the occurrence of much of the ore in soft greenstone schist, the presence of innumerable bodies of porphyry and diorite, and their obvious relationship to structural features .The property lies in the northeast part of Fourniere township in western Quebec, and within the important fault zone that geological mapping in recent years has shown is traceable wesrward through the Noranda and Kirkland Lake camps and eastward to beyond the Val d'Or region . The claims included in the property were staked by J.P. Norrie and L. K. Coffin in 1932, but gold was not discovered until i934. Production began late in 1938. The total amount of ore milled up to the end of 1945 was 2,837,091 tons from which gold having the value of $16,631,758 was recovered.The region is underlain by an alternating series of Early Precambrian sediments and volcanics cut by innumerable intrusives. These are more fully described in the works of Gunning, Ambrose, and Norman. The East Malanie property is underlain by three formations, which, named from north· to south, are : the Cadillac sediments, the Blake River volcanics, and the Kewagama sediments. In addition, there are countless intrusions of porphyry and diorite, particularly in the greenstone, occurring in all sizes up to those measurable in hundreds and even thousands of feet . These constitute a large proportion of the greenstone in places. In many parts of the ore zone there is more porphyry and diorite than schist. The greenstone itself is not homogeneous but includes peridotite, andesitic lava, and soft talcose schist.Orebodies have been found in both the Blake River volcanics and the Kewagama sediments. They are not known to occur in the Cadillac group. The ore occurs in a zone of pyrite mineralization in which almost no other metallic minerals and very little vein quartz are present. Generally, the grade varies directly with the amount of pyrite. The mineralization is later than all the rocks of the area. Diorite was a particularly favourable rock for mineralization and contains the highest grade of ore, but any rock in the fault zone may be ore-bearing, whereas the same type away from the zone is not."

Jan 1, 1954

By D. G. Macintyre

Thick westward prograding clastic wedges were deposited along the margin of ancestral North America from Mid-Proterozoic to Mid-Paleozoic time. Periodic rifting and tectonic subsidence resulted in the formation of starved sub-basins along this otherwise passive continental margin. These sub-basins host important sedimentary exhalative barite-zinc-lead-silver deposits. In northeastern British Columbia, a thick succession of Paleozoic basinal facies clastic rocks is preserved within the northwest-trending Kechika Trough. Within the trough, sedimentary exhalative barite and barite-sulfide deposits occur in starved basin sediments of Middle Ordovician, Early Silurian, and Late Devonian age. The last are the most economically sigrrificant and are hosted by carbonaceous cherty argillites and siliceous shales of the Middle to Late Devonian Gunsteel Formation of the Lower Earn Group. The largest deposit, Cirque, has reserves in excess of 35 million tonnes averaging 100J0 (Pb +Zn) and 47 g/t Ag. Other potentially significant deposits include Driftpile Creek, Bear, Mt. Alcock, Fluke, Pie and Elf. Stratiform barite deposits are also common, particularly near the basin-to-shelf transition zone. The Late Devonian barite-sulfide deposits typically are zoned: interlarninated barite-sphalerite-galena-pyrite occurring near suspected vent areas grades outward into bedded barite. Laminated beds of pyrite typically occur in hangingwall siliceous shales, particularly above the inferred vent zone. The apparent absence of epigenetic stringer sulfide zones and footwall alteration implies that the deposits were formed from ponded brines at relatively low temperature. Away from the main deposits, the favourable stratigraphic interval is marked by the presence of thin beds of nodular and laminated barite and thin laminae of pyrite. Thin tuff beds also occur locally in this stratigraphic interval and are evidence for a Late Devonian volcanic event. A paleogeographic reconstruction of the Kechika Trough in Late Devonian to Mississippian time suggests that the barite-sulfide deposits formed in third-order starved basins between uplifted, northwest-trending horst blocks that were capped by shallow-water carbonate banks. The presence of intraformational breccias suggests that fault movement accompanied barite-sulfide precipitation. This tectonic activity may have allowed the escape of heated, overpressured metalliferous brines from permeable reservoirs within the sedimentary pile. Sedimentary exhalative deposits formed where these brines were exhaled as buoyant plumes onto the seafloor, cooled, and ponded in anoxic seafloor depressions.

Jan 1, 1992

By S. M. Moon

Today, underground exploration is spotlighted as an infinitely developable area. For this purpose, many tunneling technologies were created. And until this very day, many techniques are being developed for more efficient underground movement. Although previous technologies have been developed and now being used in various forms like TMB, struck propulsion method and hydraulic propulsion method, it is hard to find a robot type exploring in small scale. But development of small scale underground exploration robot is a promising research subject for its usage in examination of soil, mineral, and subterranean resources, investigation of hazardous regions, and the military. So we developed a robot that can dig and move underground, inspired from the motion of earthworm and mole cricket. Earthworm and mole cricket dig the soil in the front and draw it off backward, so that they can move forward. We developed a mechanism that uses 2 rotating solid of revolution (bits) for pulverizing the firmly united soil in the front and put it inside the body. The bits rotate in the opposite direction of each other. While moving forward, the soil in the front moves along the spiral on the bit and is saved inside the body. The soil saved inside is taken out through an outlet in the back by a ventilation system. The ventilation system on the ground blows through a hosepipe connected to inner part of the robot and the air blows off the soil. The moving mechanism of exploring underground can be classified into 2 parts. One is to fix the blade link on the soil in a form of 4-bar link. The other one is to move forward rotating the whole link. When the blade link system for movement rotates a certain degree, one blade link is fixed, while the other one is folded in. When 2 blade links of different length rotate as it is, different torque is applied on each link. By the law of action and reaction, the link that has larger torque leads the rotation and movement.

Aug 1, 2013

By F. L. Thompson

MAN has been using lubricants of one type or another for at least four thousand years, and probably for a much longer period. We have learned from the inner wall of the tomb of Tehuti-Hetep, on which is a decoration illustrating the method of moving a great stone statue, that as early as 1650 B.C. lubricants were used to facilitate the movement of heavy loads. The Egyptians had available nearly every animal oil and fat, as well as at least thirteen vegetable oils, of our time, all used for food products and in the arts. Examination of the deposit on the axle of a chariot from an Egyptian tomb of 1400 B.C. showed it to consist of animal fat, quartz, sand, iron, and compounds of aluminium and lime-indicating a manufactured lime-soap grease made with lime-soap and possibly tallow. This would not be a bad lubricant for the axles of chariots which had to travel over sandy soil in hot weather. As to the method of grease application, it is remarkable that, from the time wheels were first used in the far distant past up to the present day, no one has ever thought it necessary to design a seal to keep the lubricant in and the dirt out. While time certainly marches on, we have today, in waggons throughout the world, exactly the same form of lubrication as was used in the earliest chariots. From the early days of the chariot until shortly before 1800 A.D. (when the steam engine was introduced), the main heavy equipment required for mining purposes, for machines of war, etc., was made of wood. The bearings were rough, but usually they had metal in the lower half. Light machinery was made of bronze, brass, or iron. Large clearances and poor alignment, plus the fact that speeds were much below present-day demands, combined to provide conditions that were quite satisfactorily met by the lubricants available. These were often produced locally by the machine operator. In northern countries, lard oil, prepared from the fat of hogs, was the universal lubricant employed in machine shop, as a belt and leather dressing, and for cutting operations. Sperm oils were used for light machinery, whereas beef and mutton tallow were more generally employed for the largest bearings. For the early steam cylinders, a slug of heated beef tallow was injected wherever the cylinders gruntingly complained of a lack of lubricant. Southern countries, however, resorted to the use of vegetable oils-olive, cocoanut, etc.

Jan 1, 1940

By D. R. Hatton

To obtain sufficient material on which to perform copper-molybdenum separation testwork a variability set of drill hole reject samples amounting to several tons was put together to include the different ore types proportions expected in the copper circuit. The samples were treated in a copper circuit pilot plant and enough mass of bulk concentrate was recovered to conduct copper moly separation tests in the laboratory. Tests consisted of stage flotation reactor (SFR) rougher pilot plant tests, conventional laboratory rougher, cleaner and 4 stage open circuit cleaner tests. The mineralogical liberation analysis of the feed and concentrate was used to model the effect of liberation on the grade-recovery relationship of the different samples. Mineral kinetic parameters for the various samples were determined by calibration to the test data. The copper concentrate results as simulated from previous studies on the same deposit were used to simulate the variability in head grade and throughput expected for the feed to the copper molybdenum separation circuit for each of the first 10 years of production. This variation in feed was then simulated through the separation circuit to obtain optimised molybdenum grade recovery curves to forecast the circuit production for each of the first 10 years. INTRODUCTION Incorporating Geometallurgy into the design for a copper molybdenum separation is especially challenging due to the low mass of final concentrate typically produced during testwork. This is due to the low molybdenum head grades and high overall molybdenum upgrading expected. With molybdenum head grades of around 300 ppm, 1 tonne of copper circuit feed is expected to produce around 300 g of molybdenum concentrate in the plant. In the laboratory however, this may end up only resulting in a few grams. Obtaining sufficient mass for laboratory testing therefore requires starting with a large initial sample and careful testwork planning to maximise the utilisation of this mass. A testwork program was designed to investigate the effect of ore variability on the copper molybdenum separation circuit (here after referred to as the molybdenum circuit). Composite samples were selected to represent the various ore types, copper content, moly content, pyrite content and clay contents expected in the copper circuit feed. These samples were run through a bulk copper pilot plant to create the feed for the molybdenum testwork. The molybdenum testwork consisted of rougher kinetic flotation tests, rougher cleaner kinetic tests, rougher cleaner kinetic tests with regrind, stage flotation reactor (SFR) pilot plant tests, open circuit cleaner tests. These tests were used to calibrate the ore kinetics in the IGS-FLEET model for simulation of the molybdenum circuit performance.

Jan 1, 2019

By D. Chakravarty, B. Samanta, D. Ghosh

Autonomous robots are useful for 3D underground mine mapping to avoid human exposure to hazardous spaces. To prepare a precise mine map, a self-navigating robot must navigate an arduous path, avoiding obstacles and sensing the environment. A prototype laboratory-scale robot was built and evaluated through a mock-up in a test mine gallery. It was outfitted with a 2D laser scanner, a stereo camera for obstacle avoidance, and a high-precision, laser-based imaging and digitizing system for collecting 3D point cloud data. Various algorithms were used for scan matching to facilitate simultaneous localization of the robot for mapping.

Jan 1, 2014

By M. J. MONEA

Canada's only economic high-swelling bentonite deposit is mined in Wilcox, Saskatchewan, by A vonlea Mineral Industries Limited. The bentonite resulted from devitrified and altered volcanic ash released during the Laramide Orogeny. Volcanic ash was deposited in a pre-Cretaceous basin that was formed by salt solution collapse structures. Sedimentary rocks in the Wilcox area belong to the Snakebite Member of the Upper Cretaceous Bearpaw Formation. Bentonite beds are 61 cm, 46 cm and 30 cm thick; these are separated by 365 cm and 182 cm of shale respectively. Saskatchewan bentonite is used primarily in the oil well industry.

Jan 1, 1984

By S. A. Sadough vanini

In this paper the influence of temperature on the flow behavior and rheological characteristics of an A356 alloy in the semi-solid state using backward extrusion process are studied experimentally and numerically. Simulation process is done by dynamic explicit in ABAQUS software for each forming condition. A cooling slope treatment was employed in order to obtain a non-dendritic microstructure. Experiments were performed in 5 temperatures and 4 different wall thicknesses. In the low forming speeds, liquid fraction had time to escape from solid phase forward the samples? wall. This condition was the main reason for the segregation phenomenon seen in the base and walls. Viscosities were determined using the force-displacement graphs obtained form back-extrusion tests. As observed experimentally, in a constant temperature, increase of shear rate resulted in decrease of alloy viscosity exponentially. Raising the temperature increases the liquid fraction hence reduces the semi-solid alloy viscosity. The results of experimental and simulation are compared and there is a good adaptation.

Oct 1, 2011

By A. G. Roach

MILLING of Nova Scotia gold ores began in 1862 with arrastras and wooden stamps and has progressed to heavier stamps followed by tables and other forms of concentration for the recovery of the sulphides. Chlorination and cyanide leaching of the concentrates has been practised, and in 1936 the combined amalgamation and all-sliming cyanidation plant of Seal Harbor Gold Mines was built. It has since been found that it is not necessary to cyanide the full tonnage and now only the concentrates are being so treated. From his experience in this enterprise, the writer presents the accompanying flow-sheet and supporting comments. While he has not the temerity to maintain that it is the best or only flow-sheet for Nova Scotia gold ores, he feels that it warrants thoughtful consideration by members of the milling fraternity of the Province. THE ORE The gold in Nova Scotia ores occurs both free and intimately associated with sulphides-chiefly arsenopyrite. Much of the free gold is quite coarse and crystalline. This is especially true when it occurs in white quartz. When in the slate, it is usually in thin plates and scales, frequently coated and discoloured. The values bound up in the sulphides are not amenable to amalgamation and must be recovered by other methods-concentration, followed by smelting or fine grinding and cyanidation. While high freight and treatment charges apply on concentrates shipped from the Province to smelters, a considerable quantity has been so disposed of in the past. However, it is hoped that a customs cyanidation plant will soon become available to producers of these auriferous concentrates in Nova Scotia.

Jan 1, 1938

By C. G. McLachlan

Professor H.E.T. Haultain: To me from time to time the urge comes to say the agreeable thing as well as the disagreeable in commenting on the work of others. It is a prerogative of age. I don't apologize. To myself I justify my action as based on a long experience of the matters with which I deal, and I like to tell myself that I have a certain responsibility in such matters on account of my detached position. This Noranda article is a very fine contribution concerning Canadian milling, and I am surprised that no word of commendation or thanks has appeared concerning it in the BULLETIN. There is altogether too much written in these days by men rushing into print, concerning laboratory work, that has not been tied into, nor has resulted in application in the field. The authors of this paper have not rushed into print. The preparation of this paper was evidently an uncongenial task. If the authors had been that way inclined, it could have spread over several lengthy papers. It is an important article because it represents an enormous amount of work in the laboratory and the mill, extending over a period of sixteen years, and resulting in fine metallurgical and economic results with a very difficult and involved problem. It is a fine article because it is so well prepared and presented. It deals with an unusual ore condition, but there is much in it of use to every cyanide millman. It leaves very little room for criticism, though there may be differences of opinion in regard to some of the chemistry phases with which I am not conversant. I am struck by the enormous amount of persistent, painstaking, conscientious research work involved, and in the careful, sincere way in which the methods and difficulties have been described. Persistence and sincerity are the key note of the effort. It should have a good educational effect on the rising generation of millmen, and it should continue for long as a work of reference, and a spur to others. There has been an important by-product, the training and development of the young men engaged in the work. Three of them became superintendents of important mills. One was sought for important work in Africa, another has joined a large research organization in the United States.

Jan 1, 1946

By D. Cruden

DISCODAT is a system of computer programs written for CANMET, Canadian Department of Energy, Mines and resources, to be used in analyzing geological data for rock slope design. The programs were written in Fortran IV for an IBM 360/67 computer. A program conditions field data from field forms for storage in a line file. Data may be selectively retrieved from the line file by a general retrieval program which uses a variety of relational operators. The retrieved data may be displayed as structural diagrams or histograms produced on a line printer or in a number of maps produced on a drum plotter. There is a logical sequence which leads to the characterization of those elements of the subfabrics of a rock mass which may be kinematically active. Structural domains within the rock mass can also be outlined by a procedure described as areal analysis. Costs for a complete analysis are usually substantially less than $l/discontinuity.

Jan 1, 1978

By P. J. Adams

Environmental regulations require means for controlling emissions of SO2 NOx and particulate when burning coal. The combustion of coal in limestone fluidized beds is one of the most promising techniques for the necessary reduction in emissions. Fluidized-bed firing, furthermore, offers potential economies in capital equipment. The world's largest steam generator applying fluidized-bed techniques was built under the sponsorship of ERDA and installed in Rivesville, West Virginia. This paper describes the design and discusses the start-up and development difficulties which were experienced during the period from initial operation to current readiness for commercial operation. Other developments leading to utility and industrial fluidized-bed steam generating equipment are reviewed. The future potential of this promising technique is discussed.

Jan 1, 1979

By B. Coupal, F. D'Hennezel

Sorption measurements show that peat moss has much stronger affinity for oil than straw, which is currently used. Microscopic studies of peat moss show a highly porous and fibrous material, and this property, associated with the phenomenon of selective absorption, had been used to absorb oil. Laboratory experiments show that peat moss absorbs up to eight times its weight of oil. Field tests have proved that peat moss can be an effective absorbent and can be used on a large scale.

Jan 1, 1972

By Gulshan Kumar Pradhan, Yogendra Pratap Singh, Dhawanm Nikhil

"Potassium (K) is one of the essential elements for the growth of plants and thereby for humans. In fertilizers, potash demand has been steadily increasing at ~3.5% annually. Water soluble potash deposits are rare and highly localized. India is neither present on the world potash production map nor it has adequate potash rich rocks. The K-bearing minerals are recovered either by using conventional underground mining methods or though solution mining methods. India possesses a vast resource of silicate rocks such as glauconitic sandstone and Feldspar. These rocks are basically a group of alumino silicate of potassium, sodium and calcium (K2O%: 5-12, Na2O%: 3-10%, SiO2%: 52-65, Al2O3%: 15-20, Fe2O3%:, 5-7 and MgO%: 2-3.5).The K extraction from silicate rocks has received little attention probably due to the slow release, the locked structure of alumina-silicate minerals, and the unavailability of appropriate economic processes & their know-how. In fact due to this India imports all of its potash demand (about 3.5 million tons per annum) from different countries.In the present work, an attempt has been made to identify the structural and chemical alteration of desired K mineral phase in silicate rock (~K2O%: 10.5, Na2O%: 2%, SiO2%: 55, Al2O3%: 19, Fe2O3%, 5-6, MgO%: 2.5) under different conditions such as acid leaching, thermal treatment and chemical processing. Different treatments are aimed to increase K availability which is related to the modifications in mineralogical composition. The modifications in the feed sample and treated samples are studied through SEM-EDAX, XRD, EPMA and optical microscope. With the combination of treatments, it is possible to extract more than 90% K and the formation of sylvite phase (water soluble) confirms the dissolution of potash values."

Jan 1, 2016

By M. C. Walton, W. Roelofs

ABSTRACT: In most cases, a refractory repair involves dealing with used refractory linings above shoulder height, defining these as overhead refractories. This paper details a method of personnel protection involving a low-pressure inflatable balloon system, installed to prevent the dislodgement and freefall of in-situ refractories. This system has been successfully applied to numerous types of vessels in the process industries in the last three to four years. This paper, prepared for the CIM Conference of Metallurgists held in Vancouver, British Columbia in October 2010, outlines details of the system and gives examples of successful applications.

Jan 1, 2012

By Chandrakala Kari, Divyang Shah, Lakshmi Kanth Reddy, Kaushik Vakil, Sanjay Sarkar, Bhavin Desai

Gases rich in sulfur dioxide generated as a by-product of smelting and converting operations of copper concentrate contain selenium apart from zinc, lead, copper, cadmium, bismuth, antimony, and arsenic. The gaseous stream is heat exchanged in waste heat boiler, dust collected in electrostatic precipitator followed by cleaning in reverse jet scrubber to remove fumes, halogens and fine dust before passing to DCDA Monsanto catalytic converter to produce commercial grade sulfuric acid. The gas cleaning section of the acid plant uses water to scrub the smelting gases. During scrubbing, precipitated solids, known as sludge, settles at the bottom of the reverse jet scrubber containing 30 to 40 wt% copper and selenium up to 40 wt% selenium. In the existing process, the sludge collected during scrubber cleaning process is directly recycled to the smelter for copper recovery. However, the selenium is expected to again vaporize due to high oxidation potential during smelting and converting, causing accumulation of selenium in sludge. In present investigation, a roasting process has been developed to recover the selenium from acid plant sludge before charging it to smelter for copper recovery. Selenium is associated with copper in acid plant sludge as copper selenide, as determined by X-ray diffraction and electron microscopy. Thermodynamic and thermo-gravimetry study revealed that the copper selenide phase present in the sludge was amenable to oxidation at 600°C forming oxides of copper and selenium (Cu-Se-O). However, the dissociation of selenium from the copper oxide was made possible by sulfatation using sulfur dioxide between 450°C to 600°C, resulting into the formation of CuSO4(s) and SeO2(g). Lab scale experiments were carried out in vertical tubular furnace to determine the optimum roasting conditions with respect to roasting time, temperature and molar ratio of O2:SO2. Using these optimum conditions, selenium up to 90 wt. % in the form of SeO2 vapors could be recovered from the acid plant sludge in a large scale commercial roaster. Roasted sludge free from selenium and containing oxides and sulfates of copper could now be recycled in the smelter for copper recovery. INTRODUCTION There is an increasing demand for minor metals due to their use in innovative technologies. Similarly, the increase in demand for selenium is expected due to disruption in sectors related to renewable energy and photovoltaic battery. Selenium is a chalcogen and a non-metal with black or red crystalline appearance. Selenium is used in the glass industry to decolorize glass and to make red-colored glasses and enamels. It is also used in solar cells and as a photographic toner. Selenium is used as a brasses in stainless steel to improve its machinability. Selenium sulfide is used in anti-dandruff shampoos. In spite of the toxicity of its compounds, selenium is also an essential trace element for humans and animals. Selenium occasionally occurs free in nature, but more often occurs as selenides of iron, lead, silver and copper. There is an urgent need for the development of new methods for selenium recovery from the existing resources. Commercially, selenium is obtained only from anode mud produced during electrolytic refinery of copper.

Jan 1, 2019

By Ken G. Kress

Syphons can be a simple, reliable and proven alternative to otherwise more complex pumping systems or low level outlet works. In a simple form they consist of a pipeline constructed over the top of an embankment or high topographic feature, connecting a source pond to a receiving pond or channel (see Photograph 1). The syphon action is initiated by removing air from the pipeline (priming) using simple devices which can be purchased ?off the shelf?. Once primed, the syphon flow rate can be controlled or stopped using conventional gate, valve, orifice plate or other devices. Repriming is not required even if the flow is stopped, provided the syphon is not drained. A limiting factor in considering a syphon as a design option is the maximum lift (i.e., vertical distance from source pond level to summit of syphon) which is approximately 9 metres, or less, dependent on syphon pipe features and site conditions. Pipeline syphons can be quickly constructed from readily available materials including steel, polyethylene and PVC pipe. They are particularly well suited to many of the unique conditions often encountered at minesites. This paper identifies situations that can sometimes be best resolved using pipeline syphons. It provides basic principles for pipeline syphon design and includes case histories of their successful application.

May 1, 2001

By Anthony McDonald, Dominic Verhelst

"Hudson Bay Mining and Smelting Co. Ltd. (HBM&S) started up a zinc plant and smelter in late 1930, employing technology of that period. The zinc plant has since converted from a roast/leach operation to a two stage pressure leach operation to eliminate sulphur dioxide emissioms. The smelter, however, is still continuing with much of the original roaster/reverberatory furnace technology. This paper reviews the process flow of the copper smelter, with some comments on past and recent changes.Smelter FlowsheetPrior to July 1993, the HBM&S smelter operation consisted of seven areas, namely feed preparation, roasters, reverberatory furnace, converters, anode casting, fuming plant, and dust collection. A simplified smelter flowsheet is shown in Figure 1. The data for tonnage of materials moving through the circuit are presented in Tables I to 4, and are representative of the time period from July 1992 to June 1993. A change in the zinc plant technology in 1993 resulted in the elimination of a zinc-bearing sulphide leach residue from the smelter feed blend, thereby greatly reducing the zinc content of slag produced in the smelter. Consequently the fuming plant and ancillary equipment, such as the drying plant, were shut down. These areas will, however, be described. With the closure of the zinc fuming furnaces all the slag from the reverberatory furnace is now discarded to stockpile.The over-all smelter metal recoveries are 96% for Cu and rn.5010 for Au and Ag. Figures 2 and 4 indicate historical production numbers of copper, silver and gold, respectively. A review of the minor element distribution in the smelter can be found elsewhere."

Jan 1, 1994