Search Documents

By K. Maruyama, T. Nagasaka, R. d. Chairaksa-Fujimoto, T. Miki

Electric arc furnace dust or EAF dust is considered as a hazardous waste but contains a significant amount of economically attractive non-ferrous metals especially zinc as zinc ferrite (ZnFe2O4) and zincite (ZnO). The hydrometallurgical process is one alternative choice because it has the advantage of low energy consumption. The leaching of ZnO from the dust is very easy. However, the complex major zinc compound in EAF dust is ZnFe2O4, which is very stable and insoluble in alkaline or acidic media under delicate conditions, and causes the low zinc recovery yield by hydrometallurgical process. Moreover, halogens and heavy metals in the dust are also problematic. In order to develop a new effective EAF dust treatment process, the authors have proposed "CaO addition process" as pre-dust treatment to transform all of ZnFe2O4 in the EAF dust to ZnO and Ca2Fe2O5. In this study, the selective zinc leaching from the CaO treated EAF dust with NaOH and NH4Cl solutions was carried out. The effect of temperature, reaction time and solute concentration were systematically investigated. All of zinc in CaO treated EAF dust was successfully leached into both solutions.

Jan 1, 2014

By Matt Manson

Diamonds in Canada: Recent Advances in Exploration Methodology and Advanced Stage Assessment 1. Exploration Methodologies ? Prospectivity Mapping ? Surficial Geochemistry ? Geophysics 2. Advanced Stage Assessment ? Petrology and Diamond Paragenesis ? Micro/Macro ratios and Macro grades ? Value Sampling and Modeling

Apr 1, 2005

By A. G. Eccles

Western Mines' milling circuit produces three concentrates (copper, lead and zinc), with the tailings being disposed of at the bottom of Buttle Lake. In view of the mine's location and the method of tailing disposal, a comprehensive pollution control program has been in effect since start-up. Changes -in the ore over the past few years have required the use of increasing quantities of sodium cyanide in order to effect a good copper-lead separation. This led to the use of alkaline chlorination for destruction of ?residual cyanide and precipitation of dissolved copper contained in the tailing effluent. The development of Western Mines' alkaline chlorination plant is discussed in detail, including initial test work and the evolution of procedures leading to the present operation. The current monitoring program is also reviewed.

Jan 1, 1977

By John B. Phillips

The mine is entered by a central vertical shaft, strongly timbered, and containing two compartments-one for the passenger cage, the other for the large skips bringing the ore to the surface. A man-way, for emergencies, is also provided, parallel to the shaft. The cage is a single-deck steel box, carrying about thirty persons; by means of arrangements above and below, it can also hoist and lower materials needed in the workings. Levels are run at intervals of 100 feet. In special cases, where the ore conditions warrant, sub-levels are operated, such as those at 1,113 feet and 1,123 feet (Fig. 7), which are connected by winzes with the 11 th level. One of these was pushed for 40 feet, and then abandoned because it was unprofitable to take up ore of the grade encountered. The ore between levels is removed by stoping. The drifts follow the course of the veins as much as possible, with numerous cross-cuts. Winzes, raises, connections, etc., are blasted out where needed. The main drifts are at least 8 ft. high by about 9 ft. wide. All former narrow drifts had to be widened sorne time ago, by ruling of the Ontario Department of Mines, to lessen the danger of accidents with cars in the small passages. Accurate plans of the under-ground workings are kept in the office, and extensive surveying is always being done underground to keep the maps up to date, measure the cubical contents of stopes, and so forth. Timber is extensively used in the construction of supports and chutes, and in the sinking of the shaft. Steel and concrete are too expensive to compete with timber, which 1s abundant in such sections as have escaped forest tires.

Jan 1, 1926

By R. W. Bruce, K. W. Downes

"IntroductionSULPHUR production in Canada from all sources for the year 1953 amounted to about 375,000 tons. Except for 16,000 tons of elemental sulphur derived from natural gas, this production was in the form of by-product pyrites, liquid sulphur dioxide, and sulphuric acid. In the same year, Canadian industry imported 359,000 tons of elemental sulphur from the United States. The cost, including transportation charges, to Canadian consuming plants ranged from $35.00 to $45.00 per long ton, depending upon location.Although most of the sulphur consumed is used in the oxidized form it is often most convenient to buy sulphur in the elemental form, and convert it to sulphur dioxide or sulphuric acid in situ as required. This is because elemental sulphur is easily shipped and stored, weighs only half as much as an equivalent quantity of sulphur dioxide and one-third as much as the corresponding quantity of sulphuric acid, and is readily converted to these forms in a sulphur burner. A process, therefore, which could economically recover elemental sulphur from sulphide ores would be most attractive.Since the turn of the century, notable improvements have been made in extractive metallurgy, but until recently only limited attention has been paid to the possibilities of elemental sulphur recovery. This has been due to the plentiful supplies of cheaply mined Frasch sulphur which have been available on the world markets."

Jan 1, 1955

By John D. Galloway

Mining is one of the important primary industries of Canada, with a gross production in 1927 estimated at $241,773,000- the highest in the history of the country-and an impressive dividend record. It is quite apparent, therefore, that mining is a business worthy of the careful attention of the people of Canada. Furthermore, with a vast undeveloped territory more or less mineralized, it is highly probable that our mining industry will continue to expand indefinitely, with a consequent increase in production and in the amounts of the yearly profits distributed. In recent years, the public has taken a larger interest than formerly in mining-an interest, moreover, that is not academic, but primarily from the viewpoint of profits. It is quite evident that mining is a profitable business, at least to some, and the average man on the street, hearing of these profits, is attracted thereto. I have no doubt that many of you have .read in promotion prospectuses, with figures to prove it, that mining is the most conservative, the safest, and the highest-yielding business in the world. Now, a lot of this information is best judged by the old saying that "While figures don't lie, liars figure". At the same time, mining, properly conducted, is a profitable business, even though speculative, and undoubtedly much profit will come from Canadian mines in the future. In this paper my conclusions regarding mining investments are based largely on British Columbia experience, together with some slight knowledge of mining conditions in the other Provinces. It is considered, however, that the inferences drawn are applicable to mining throughout Canada.

Jan 1, 1928

By S. P. Cashin, D. Kashuba, W. Esplin

Barrick has had 6 autoclaves in operation at the Goldstrike Mine, North of Carlin Nevada, since 1993. The 6 autoclaves operate in parallel, processing slurry of gold ore. The gold in the ore is predominantly associated with, and encapsulated by, sulphide minerals. It is necessary to oxidize at least 90% of the sulphide mineral before the gold can be concentrated using a cyanide/carbon-in-leach (CIL) circuit. Sulphide oxidation chemical reactions occurring in the autoclaves are exothermic; however, the sulphide content in the ore is not high enough to operate the autoclaves in an auto-thermal mode. Heat from steam is added to the first 2 of 5 autoclave compartments to initiate the sulphide oxidation reactions. The steam used to heat the autoclaves is supplied by three boilers, which are fuelled with propane gas. The completion of a few operations and maintenance projects in the last 2 years has resulted in a 50% reduction in propane energy requirements. The autoclave operating temperatures were minimized. Excess oxygen addition was held as low as possible. The material of construction for the compartment walls inside the autoclaves was changed from brick to Titanium metal. And, the speed of the autoclave slurry agitators was increased. All of these activities had an impact on the propane energy requirements of the autoclaves. Presented below is a description of the autoclave systems, and a discussion of how the energy needs were reduced, resulting in significant operating cost savings.

Jan 1, 2004

By J. Guha, A. Gobeil, P. Pilote, A. Tremblay, E. Dimroth

The Mount Bourbeau Lac Berrigan area is located just to the north of the Town of Chibougamau. The axial trace of the Chibougamau syncline borders the northern part of both areas. The area contains Archean rocks of the Roy Group, intruded by the Cummings Complex and the Line Lake tonalite stock. Proterozoic sedimentary rocks occur in a series of outliers. Various Cu, Zn, Pb, Ag, Au and Mo showings are dispersed over the area in a wide range of time and space. Pre-Kenoran (stratiform and stringer) showings related to volcanic activity may be distinguished as well as the syn-or post-Kenoran (vein) types whose nature is imprecisely known. In this area, the stratiform showings occur in the Gilman and Blondeau Formations, whereas the vein type showings occur for the most part in fractures or breccias within or along the contacts of the various sills of the Cummings Complex. Mount Bourbeau is distinguished by the greatest variety of showings as well as the proximal volcanic facies of the Blondeau Formation. A volcanic centre is presumed to lie a short distance north or east of the locality. Locally, the Line Lake stock contains significant silver, molybdenum and gold mineralization. Its role as a metal reservoir, a source of heat for the circulation of hydrothermal fluids and its control of the local tectonic style remains to be determined.

Jan 1, 1984

By B. Courtaud, L. Donati, V. Weigel

As a growing mining company, ERAMET is looking for new positions in the strategic metals market. In this context, the Gabonese Maboumine pyrochlore deposit is currently being studied for the recovery of niobium, tantalum, rare earths and uranium. This ore shows mineralogical and chemical characteristics that make it challenging to process by existing practices, from both technical and economic points of view. ERAMET has developed since 2008 an innovative hydrometallurgical process, which has been successfully operated at a pilot plant scale (more than 35 weeks in continuous). The upstream part of the process aims to dissolve valuable elements in sulphuric acid. The first step is dedicated to dissolve the ore matrix, leaving the pyrochlore unleached. The second step consists in chemically breaking down pyrochlores in order to form soluble species of the valuable elements. After dissolution, the valuable elements are separated into different flows: niobium and tantalum are recovered and transformed as commercial ferroniobium on one side, and rare earths and uranium remain in the solution to be recovered in the downstream part of the process. The main goal of this paper is to discuss the upstream part of the process, which has given successful results.

Jan 1, 2014

By T. Schepp, T. Friedrich

"The natural stage of deep mines operation is a closure of unnecessary shafts. It is extremely important to ensure a proper shaft closure to avoid stability loss and the associated damage to surface facilities in the future. For the still active shafts, it can be done by a dedicated shaft closure design, but even then, depending on the shaft closure method, it may be necessary to perform regular shaft inspections. The paper presents a short overview of shaft closure methods and available tools and devices developed in the last time for such shaft inspections. INTRODUCTION The natural stage of deep mines operation, commonly occurring after depletion of the reserves of mined materials, is a closure of unnecessary shafts. All over the world, the number of liquidated shafts grows continuously and the problem of shafts disposal is especially critical for deep shafts. The typical depth of 600 m of currently liquidated shafts in Poland may already be seen as a challenging task. The greater is the challenge of shaft closure in Germany where the last active coal mines for shafts with a depth of up to 1,300 m have been recently closed. It is therefore extremely important to ensure a proper shaft closure to avoid stability loss and the associated damage to surface facilities in the future. For the still active shafts, it can be done by a dedicated shaft closure design, but even then, depending on the shaft closure method, it may be necessary to perform regular shaft inspections. In many cases, it is more important to inspect old, abandoned shafts, where the wall stability or even liner type are not fully known. SHAFT CLOSURE METHODS Abandoning a shaft is a complicated task, as shafts, being the link between the surface and an underground network of workings, disturb hydrogeological and gaseous conditions in the rock mass (Sztelak, 1991). Closure procedures at older mine sites have been carried out in accordance with earlier legislative requirements. For very old shafts (+100 years), it means in many cases only a sealing of the shaft entrances by means of timber or concrete slabs. In the 20th century, the shafts were also closed by means of filling with grainy materials, but even then the retrospective activities at abandoned mine sites were extremely limited and in most cases no further monitoring measures were performed. The possible consequence of an improper shaft closure and lack of monitoring is presented in Figure 1."

Jan 1, 2019

By P. Nelson, B. Salt, J. A. Scott, H. Shang

ABSTRACT In a nickel smelting process, large amounts of off-gas emissions are generated, which can cause serious environmental and plant hygiene problems if not properly treated. With increasingly stringent environmental regulations, an enhanced understanding of well-controlled, off-gas cleaning systems is vital. In this paper, dynamic models for an industrial smelter, off-gas system tackling hazardous sulphur dioxide, carbon monoxide, and carbon dioxide are developed using mass continuity, momentum, and energy conservation laws. The effect of air in-leakage is explored under different operating conditions. The developed models provide an enhanced process understanding and a necessary basis for highperformance control analysis of smelter off-gas systems.

Jan 1, 2011

By G. M. Furnival

A PROGRAMME of structure drilling was commenced in the Southern Alberta Plains in June, 1943, for the purpose of determining the geological structure of the underlying sediments. More than 270 holes have been drilled throughout an area of some 1,800 square miles or 1,000,000 acres (see Figure 1). The Southern Plains of Alberta are covered by a mantle of glacial drift,' at places exceeding 200 feet in thickness. Only where this mantle has been dissected by deep drainage channels is bed-rock exposed to any great extent. Along such channels, surface geological mapping can be conducted to ad- vantage. Accordingly, geological mapping was commenced _in 1942 and continued each season to the present. To supplement this information, a survey of the water wells was carried on in conjunction with the mapping. However, to obtain more positive and evenly distributed structural control throughout the area as a whole and to define more adequately structural trends indicated by the preliminary mapping, it was necessary to resort to the use of drills to penetrate the glacial mantle. Various types of light drills are commonly used for this purpose and provide geological information in the form of drill cuttings, cores, drilling time rates, etc. Correlation of information is generally obtained through comparison of cored sections, drill cuttings, micro-fossils, and drilling time rates. However, in this case the holes were electrologged and correlations were made chiefly by comparison of such logs. The data so obtained is plotted and portrayed in the form of structure contour maps on recognizable stratigraphic horizons and in the form of isopach maps of the recognizable stratigraphic intervals penetrated in the holes. This method had not been widely used in Alberta previously and the technique employed was necessarily developed after the project began.

Jan 1, 1945

By G. Belzil, F. Robichaud, M. Fullam

ABSTRACT The Goldex mining and milling complex is operated by Agnico-Eagle and is located in the Abitibi greenstone region of northwestern Quebec, Canada. Commercial production started in 2008. Average gold recovery is 93.5% with approximately 68% of gold recovery coming from the gravity circuit. During the first three years of production, three gravity audits were carried out to optimize performance of the gravity circuit. This paper presents results of the audits and the development of a model linking gravity and overall gold recovery, and outlines improvements made to increase gravity performance and reduce operating costs.

Jan 1, 2013

By M. J. Latva-Kokko, T. J. Riihimäki

"Oxidation autoclaves are normally operated at elevated temperature and pressure. The improvement in kinetics is due to combined effect of temperature and partial pressure of oxygen. In this paper exclusive effect of pressure has been studied with a low grade sulphide ore at below 100 °C temperature. These studies are related to development of a novel tower-like reactor that utilizes hydrostatic pressure. Technology is designed to generate high amount of effective fluid volume for high solid content slurries with lower energy consumption and improved kinetics compared to normal atmospheric operation.INTRODUCTIONEconomical utilization of low-grade ores requires handling of enormous amount of material. This sets new requirements for process equipment in terms of size and energy efficiency. For example on the field of mineral processing this has lead to a six fold increase in the operating volume of mechanical flotation cells over the past two decades. Ore beneficiation methods like flotation greatly reduce amount of material that needs to be further processed in smelters or hydrometallurgical refineries. However with some ore types, such as nickel laterites and refractory gold ores, traditional concentration technologies cannot be utilized. Thus direct leaching of ground ore could be an attractive option. In many cases normal atmospheric tank leaching has traditionally been a non-feasible option mainly due to high capital and operational expenses induced by large amount of stirred reactors required. Main restriction for increasing reactor size to beyond 500 m3 has been mechanical load and power requirements set by mixing in cases when high dispersion efficiency of gas is required. THEORETICAL BACKGROUNDIn hydrometallurgical industry autoclaves are typically operated at elevated temperature and pressure. In many cases increase in operating temperature is the desired phenomena and improvements in kinetics are strongly related to that. Thus increase in pressure might be induced solely by water vapor pressure. However when gaseous feed is present, pressure itself has a strong effect on leaching kinetics for various reasons and its role should not be neglected."

Jan 1, 2012

By D. G. E. Kerfoot

In September 1945, when the Lynn Lake nickel orebody was discovered Sherritt Gordon Mines was a small copper mining company with rapidly depleting ore reserves at its single producing mine at Sherridon in the Cold Lake area of Manitoba, 100 miles north of The Pas. The company has been formed in 1927, largely through the efforts of Eldon L. Brown, a 27-year old mining engineer, with the financial backing of Thayer and Halstead Lindsley and the Gordon family. The Lindsleys were American mine promoters who had been successful in the Sudbury area, and the Gordons had extensive interests in the lumber industry in northern Ontario. Carl Sherritt, who gave his name to the company, was an American trapper and prospector who had staked the copper property and sold his interest to the new company. Carl Sherritt died in a flying accident at The Pas in 1928. The Sherritt Gordon Mine started production in 1931, shipping copper concentrate to the new Hudson Bay copper smelter at Flin Flon, Manitoba. In 1931 the price of copper was 18¢/lb. Within a year the price had fallen to 5¢ /lb and the mine was forced to close. It remained closed through the Depression years.

Jan 1, 1999

By Dong-Hyeun Koh, Yun-Soo Lee, Min-Seok Kim, Hyoung-Wook Kim

High strength AA7068 (Al - 7.88 wt.% Zn - 2.68 wt.% Mg - 2.07 wt.% Cu) aluminum alloy strip was successfully fabricated by horizontal-type twin roll casting. A simulation technique was used to obtain the range of casting conditions for fabricating strip without defects. The cast strip with thickness of about 5 mm was hot rolled, intermediate annealed, cold rolled to final thickness and subsequently annealed at various temperatures. Tensile properties of annealed and the aged specimens were evaluated at ambient temperature. Tensile strength and elongation of the annealed sheet are about 365 MPa and 28%, respectively. Also, the tensile and yield strength after the aging at paint baking condition (180 °C x 0.5 h) are 586 MPa and 551 MPa, respectively. Therefore, it is expected to show good formability prior to press or stamping and also provide high dent resistance after paint baking treatment.

Jan 1, 2015

By Michel Mellinger

This paper presents preliminary results of a project aimed at obtaining a better understanding of the genesis of gold mineralization in northern Saskatchewan using lithogeochemistry. The properties sampled were: Weedy Lake (B Zone), Waddy Lake (Komis Zone) and Wedge Lake (Twin Zone) in the La Range belt, and the Rio mine in the Flin Flon area. Although the three vein-type deposits rudied here (Weedy Lake. Waddy Lake, Rio deposit) occur in different geological situation . a common gold deposition mechanism appears to have been active at all three location . Hydrothermal fluids carrying sulphur in solution in exces of gold thio-complexes moved through fractured host-rocks until they reached a site where pyrite precipitation wa triggered. As pyrite precipitated, the a/ aAu activity ratio of the fluid decreased. until a critical thre hold was reached and gold thio-complexe were de tabilized . resulting in the co-precipitation of gold and pyrite. The conditions triggering the precipitation of pyrite appear to have been: the abundance of iron in host-rock ~ilicates at Waddy Lake. and temperature decrease upon the reaching of structural trap~ at both Weedy Lake and the Rio deposit. with additional involvement of carbonatizationrelated reactions between fluid and host-rocks for the latter. In addition to pyrite precipitation , potassic alteration of the mafic metavolcanics is observed at Waddy Lake. while at the Rio deposit, the extensive carbonatization of the host-rocks i coupled with the deposition of chlorite that may have been remobilized from the altered mafic host rocks. In both the B Zone at Weedy Lake and the Komis Zone at Waddy Lake, a di tinct vanadium signature give some clue about the direction in which the hydrothermal fluids have moved . and the interpretation made is con istent with the geological ituation in either case. As for the Wedge Lake deposits, the distinct base metals-precious metals a sociation within a sulphide-facies iron formation confirm the volcanic exhalative origin of this gold mineralization .

Jan 1, 1986

By P. E. Davidson

The management of solid waste is known to be a large and increasing problem in high-population areas throughout the world. It is not necessary here to add further definition to the nature and magnitude of the problem. Instead, it is the purpose of this paper to describe a new process, called the Andco-Torrax System, which will be of use in converting municipal solid waste into useful energy forms and a granulated slag by-product. The paper includes a description of the first commercial plant for the process.

Jan 1, 1977

By L. D. Roper

"This paper introduces novel comminution flowsheet concepts involving a novel apparatus, eccentric-high-pressure-centrifugal-comminution (eHPCC), and forthcoming advantages to the international mineral processing community. eHPCC is one-machine synergising high-pressure-rolling surfaces, high-intensity-attrition and centrifugal classification. eHPCC has demonstrated: an absorbed power- intensity of 4 MW/m3; receipt of lump feed whilst producing 80% of product particles less than (p80) 120 µm (choke-fed, dry, open circuit without grinding media; an inert comminution environment); tramp metal tolerance, and a minimum embodied-free-energy saving of 15% as compared against conventional comminution (this comparison withstanding 133-times difference in throughput). Furthermore, this paper introduces: process design and operating characteristics of eHPCC (wet, dry, with and without grinding media); reline considerations (vertical-lift without confined-space). The international mineral processing community is invited to consider eHPCC as an alternative to conventional comminution circuits and/ or complimentary so as to enhance existing process flow sheets.INTRODUCTIONEccentric-high-pressure-centrifugal-comminution (eHPCC) was conceived in 2013 (Patents pending) and has the potential to eliminate the in-efficiencies and complexity of conventional tumbling mill circuits. During the development and testing phase eHPCC demonstrated improved energy efficiency and sustainability offsets.eHPCC will compliment any upstream feed source, be it run-of-mine (ROM), primary crushed rock, or any other conventional comminution stream such as tumbling mill oversize. Another novelemerging technology, Conjugate Anvil-Hammer Mill (CAHM) (Nordell and Potapov, 2011), receiving ROM, will be a complimentary open-circuit feed to eHPCC for very high throughput flow-sheets.eHPCC may compliment downstream process requirements through selective mineral liberation. Selective mineral liberation is entirely feasible as the ore is comminuted upon itself (autogenously) in the high pressure zone caused by the synchronous rotating components."

Jan 1, 2016

By A. Klingberg, M. Svensson, N. Smolko Schwarzmayr

"Removal of silicates and carbonates from sedimentary phosphate ores by the use of new synthetic collector/formulations was investigated in a comparative study with traditionally used collector systems as references. In the direct carbonate flotation the new formulations showed higher efficiency, contributed to an improved balance of P2O5 recovery and P2O5 enrichment in the recovered material. Efficiency of the new formulations containing synthetic surfactants was 1.5–2 times better than potassium salt of fatty acid sulfonate based formulations that are traditionally used for that purpose. The new formulations also provided up to 7% increase in P2O5 recovery at the same P2O5 grade. The new synthetic collectors for removal of silicates showed extremely good selectivity towards silica bearing minerals. The selectivity factor for the flotation tests when new formulations were used was 32–52 and for the flotation tests with the traditional collectors: 20–32. The ratio between distribution of an amount of silicates (as SiO2) and distribution of phosphate in the froth (waste) is defined as the selectivity factor. The new formulations provided more than 2% decrease of the amount of SiO2 at the same P2O5 recovery.INTRODUCTIONPopulation growth and decrease of arable land are the main reasons for constant increase of consumption of apatite (phosphate ore) in the fertilization field (Lannefors, Gorochovceva, Klingberg, Lima, & Gustafsson, 2015). Fertilizers play a key role for farmers to produce more with less land. The phosphate component of the fertilizer is vital for producing healthy and large amount of crop. As a result the demand for phosphate rock is growing.The largest producers of phosphate rock are the Unites States, Morocco, Tunisia, China, Russia, and Brazil. The term “phosphate ore” includes all phosphate-bearing minerals and rocks, but only two of them are of industrial interest: apatite (igneous origin) and sedimentary phosphate (Peres, Araujo, El-Shall, Zhang, & Abdel-Khalek, 2007). The majority of the world’s phosphate deposits are of the sedimentary type. There are two different types of sedimentary phosphates: siliceous and carbonaceous which are categorized based on gangue minerals (such as quartz, carbonates, mica, and clay)."

Jan 1, 2016