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By J. H. Bain, D. C. Haigh, L. C. Parsons

Jan 1, 1964

An extensive study was carried out to evaluate the performance of Outokumpu OK50, OK38 and Maxwell MX14 cells at ComincoÆs Red Dog flotation concentrator in Alaska. Tests were conducted by varying operating conditions of the cells installed in different circuits in the plant. The hydrodynamic and gas dispersion properties were measured and the metallurgical performance of the cells was evaluated for each condition used in the tests. This paper highlights the importance of superficial gas velocity, bubble surface area flux, gas hold-up, power consumption, residence time distribution and froth flow behaviour in optimising cell performance. The findings of these tests provide valuable insights into selection of the best cell operating conditions to optimise circuit performance.

Jan 1, 2000

By Katsuyoshi Kondoh

The synthesis processing of Mg2Si or Mg2Si/MgO at lower temperature from the elemental magnesium alloy powder/chips and Si or SiO2 powder mixture was established via the repeated plastic working (RPW) based on Powder Metallurgy (P/M) process. RPW is much effective on the mechanical breakage of MgO surface films, which prevent from the solid-state reaction between Mg and Si powder. The solid-state synthesized Mg2Si particle of 200nm-2JIm is extremely fine, compared to that via the conventional casting process, causing the coarse one of 50-100um. This is because of not coarsening during the solid-state synthesis of Mg2Si. By using in-situ forming process of Mg2Si via RPW and pre-heating before hot working such as extrusion and forging, the magnesium composite material with Mg2Si or Mg2Si/MgO dispersions was developed in employing Si or SiO2 particles, respectively. For example, when employing AZ31 chips as raw materials of the matrix, it has low density of 1.85g/cm) and extremely superior mechanical properties, such as tensile strength over 350MPa with 5-10% elongation and Young's modulus of 47-50GPa, to the conventional Mg-Al-Zn alloys. The Mg composite alloy wires and pipes were produced via the hot extrusion process in the manufacturing plant, and also showed excellent mechanical properties.

Jan 1, 2003

By Nathan Rouse

This blast mitigation study examined the effects of a barrier wall on explosively driven pressures. This area of blast mitigation is of interest due to the many different applications involved in protecting a target from an explosive attack.

Jan 1, 2012

By Tao Xuea

Gold frequently occurs in nature in the form of a gold-silver alloy. Thus, investigation of the electrochemical behavior of gold-silver alloys in cyanide solution has practical significance. In this paper, the potentiodynamic method is used to determine the anodic polarization curves of gold-silver alloys (Au-10% Ag and Au-50% Ag) in cyanide solutions. To facilitate the interpretation of the results, complementary experiments conducted in NaOH solution in the absence of cyanide are also reported. The results for the Au-Ag alloys are compared with the polarization behavior of pure gold and pure silver. With the aid of potential-pH diagrams for the Au- and Ag-CN-H20 systems and electrochemical kinetics concepts, the dissolution mechanism of gold-silver alloys, the effect of the presence of silver on the cyanidation of gold, as well as the factors which control the anodic reaction rate are clarified.

Jan 1, 1998

By C. Dorfling, W. A. Rossouw

"Hydrometallurgical processes used for metal recovery from waste printed circuit boards (PCBs) typically involve dismantling, shredding and physical separation prior to successive leaching stages for selective dissolution of different metals. The principles of the physical separation units are well understood, but valuable metal losses of more than 30 % can be incurred during these processing steps. The impact of the physical separation units’ performance on downstream leaching operations have not been defined; this prevents the development of a well-integrated process. The objective of this project was to determine to what extent the base metal leaching behavior depends on the physical separation pre-treatment. PCBs were shredded to 100 % passing 2 mm before physical separation by dense medium separation (DMS) as well as magnetic separation. Batch leaching tests using various concentrations of sulfuric acid were conducted on three feed fractions: (1) shredded PCBs without any physical separation, (2) heavy fraction recovered from DMS, and (3) non-magnetic fraction recovered from the DMS heavy fraction. DMS increased the metal content in the feed from 48 % to 75 % on a mass basis, but 70 % of the gold and 20 % of the copper reported to the light fraction. The application of magnetic separation to the heavy fraction produced by DMS removed 67 % and 61 % of the iron and nickel, respectively, while negligible amounts of non-magnetic metals were removed. Although DMS successfully concentrated the feed and magnetic separation removed the majority of iron and nickel, these steps did not result in any improvement in the rate or extent of copper leaching. Metals generally leached faster when the sulfuric acid concentration was increased from 1 M to 2.5 M; this effect was seen to be more pronounced for pretreated feed. INTRODUCTION The fast rate of technological development has led to a decrease in the service life of electronic devices. This is resulting in an increased rate of electronic waste generation. The recovery of metals from electronic waste is of environmental and economic interest. The majority of these metals are typically located on printed circuit boards (PCBs) within electronic devices (Tuncuk, Stazi et al., 2012). Hydrometallurgical processes are considered a viable option for small scale metal recovery from waste PCBs, and generally involve the following steps: disassembly for removal of hazardous and reusable parts, size reduction, physical separation, successive leaching stages for metal dissolution and finally recovery of metals from leach solutions."

Jan 1, 2018

By Askew J. E

All facets of current practices of cable dowelling at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited are re- viewed. This includes materials specific- ations, installation practices and design pro- cedures. Cable dowelling for cut and fill stoping, square set timber stoping, longhole open stoping and level reinforcement is considered. Installation is simple and can be mechanised to eliminate heavy lifting. Quality control is essential for optimum performance of the re- inforcement. Design patterns must consider the mining method, reinforcement economics, acceptable stability standards and mine production priorities.

Jan 1, 1977

By Alexander B. Morris

Studies such as the investigations into the solubility of gases in crude oil under various conditions, which have been carried on during the past three or four years, are very interesting from an academic point of view, but this consideration alone is hardly sufficient to warrant the large contributions from the industry necessary to maintain them. Some definite benefit to the industry as a whole should be forthcoming. The purpose of this paper is to direct the attention of company engineers, and company executives, to some of the ways in which the information gained from these studies can be made directly profitable. This work has two principal economic aspects. One affects the investment budget, and through it the financial requirements of the companies. The other affects operations, and through this course is reflected in current earnings. It will be shown that, as a direct result of the investigations into gas solubility, undertaken in the recent past by various investigators, it is now possible: 1. To determine more accurately the amount of reservoir oil originally present. 2. To obtain closer control on operating conditions, to effect more economical recovery. 3. To predict earlier and more dependably when and how much surface lifting equipment will be needed. 4. To reduce, or entirely avoid the very large investment in gasoline recovery equipment now frequently found necessary. 5. To control the gravity of the pipe-line oil so as to secure the greatest possible revenue from the products of the well. 6. To effect the recovery of a large amount of gasoline now wasted while the practicability of a gasoline recovery system is being decided. 7. To plan operations, by comparison with the history of old properties operated without this new information, so as to avoid the mistakes of ignorance made in the past. These points will be discussed in the following pages, though not necessarily in the order stated. There is so much overlapping of the points themselves, and of the data from which they have been drawn as conclusions, that to treat them in any particular order would require

Jan 1, 1935

This paper records the observations of faulting in the Black Star mine workings. By classifying the faults into two groups, i.e., strike faults and transverse faults, and by pointing out the differences between the groups and their effects on the silver-lead-zinc orebodies, a time relationship between the two groups of faults and the sulphide mineralisation is suggested.GENERAL GEOLOGY AND MINERALISATIONFolding and faulting are closely related to the mineralisation in the shales by silver-lead-zinc and iron sulphides.Commonly the various sulphides are fine-grained and closely associated with one another. However, exceptions do occur locally, where massive coarse galena, sphalerite, pyrite, and to a lesser extent chalcopyrite, have been observed singly or closely associated one with the other.In the main, the sulphide mineralisation forming the orebodies occurs as replacement of, and infilling along, the sheared bedding planes of the finely bedded shale host rock.The shales in general strike north-south with an average dip to 60° to the west; strong shearing along the bedding planes is evidenced by much slickensiding and slaty cleavage.Sequences of finely bedded shales of varying stratigraphic thicknesses alternate with very. massive beds, and it is in the more highly sheared thinner beds that the greatest concentration of sulphides occurs. The unmineraIised massive beds of shale, 11 in. up to 12 in. in thickness, occur singly or in groups between, and to a lesser extent. within, the orebodies. The massive beds resisted sulphide replacement and impart to the orebodies a most prominent banded structure.

Jan 1, 1953

By Paul Grady, Martin Froehling, Curtis Mohns, Eliab Roman

"Since the idea of processing rock to unlock the valuable minerals inside was put into practice, efforts to improve production began. Methods have been learned that allow for operation in environments and under circumstances where it would not have been possible until now. All existing operations have experienced at least some form of productivity improvement measures. The objective is simple: generate more product of better quality in less time and at lower unit cost. Since the year 2000, various modifications have been made at the Kemess Concentrator in efforts to improve productivity. The following is a discussion of these modifications and their contributions to the success of the operation.INTRODUCTIONThe Kemess South Mine, a major producer of gold and copper, is located in north-central British Columbia. Kemess was brought into production in May 1998 by Royal Oak Mines with a modern mill controlled by a fully integrated Foxboro IA DCS system and employing 134 people. On February 11, 2000 Northgate Exploration Limited (now Northgate Minerals Corporation) acquired Kemess Mine from receivership. Since acquisition in 2000, Kemess has seen many accomplishments, including the reduction of costs by 40% site wide.The mill has a nameplate capacity of approximately 56,000 tonnes per day which is processed through a Metso (Svedala) 60” x 89” Primary Gyratory Crusher and then conveyed by a 60” conveyor to a stockpile with 48 hours of total storage capacity. The nominal minus 6” rock from the stockpile is fed to two parallel grinding circuits (A & B). Each section consists of a 10.4 m F x 4.7 m SAG mill with dual drive motors (4,480 kW apiece) discharging onto a 2.4 m x 7.3 m Metso (Svedala) single deck vibrating screen to remove the coarse material for recycle to the SAG mill by a Continental 45º high angle sandwich conveyor. Screen undersize is pumped along with ball mill discharge to a cyclopac consisting of twelve Krebs 66 cm F cyclones to classify flotation feed to a size of approximately 65% minus 200 mesh. Cyclone underflow feeds a Metso (Svedala) 6.8 m F x 11.0 m ball mill, also with dual drive motors (4,480 kW apiece). The primary grinding circuit has 35,840 kW available for grinding."

Jan 1, 2005

By Steve Dillingham

The explosives business by nature is providing a specialized, valued service and associated products to a variety of customers whether mine, quarry or construction related. The level of performance demanded by the customer will typically coincide with his or her individual needs. Some will seek out the skills and knowledge of a blasting expert, while the focus of others is simply on production amounts.

Jan 1, 2003

By James M. Tantalla, Dwight Metcalf, Roderic A. Ellman Jr.

"The construction of a new low head hydro-electric plant at the Cannelton Lock and Dam required the design and construction of a cofferdam to accommodate a deep excavation extending approximately 150 feet below the Ohio River levels. The new plant, which generates about 390 GWh of electricity annually, is owned by American Municipal Power (AMP). A specialist team was assembled to design and construct the cofferdam, marine dike and CB slurry wall that helped make the project successful and on time for project delivery.Because the new plant diverts water from the locks and dam through a powerhouse to generate power, it would need to be partially in the river to operate properly. To accomplish this, approximately 250,000 square feet of land was reclaimed from the river by construction of a marine dike. The dike, combined with the design and construction of a 150 foot deep cement bentonite (CB) cutoff wall enabled construction of the new plant in the dry. Extensive dewatering analyses were performed using Modflow to evaluate pumping requirements and the number of wells needed to maintain ground water at required levels within the side slopes and final subgrade. A monitoring program consisting of inclinometers, piezometers and movement monitoring points were used to monitor cofferdam stability and performance throughout construction. Detailed two and three dimensional stability analyses that included a parametric study of fluctuating river levels and slurry unit weight were performed to ensure stability and suitable low permeability of the trench during cut-off wall excavation both on land and in the marine dike. The wall was constructed with both a hydromill excavating primary panels and a clamshell following behind to construct secondary panels. Data acquisition systems onboard the excavating equipment allowed for detailed confirmation of the continuity of the wall at each interface between panels. Another challenging aspect was the CB mix design for the trench. The cofferdam required the construction of a 1,300-foot long marine dike downstream of the existing dam up to 100 feet tall founded on existing river sediment to enclose the site and cut-off the seepage into the excavation from the river. Marine dike construction utilized vibro-compaction to pre-densify granular fills placed underwater through which the CB trench extended."

Jan 1, 2016

By Henri-Loui Jacob, Suzie Nantel

"Depuis la fin des annees 1800, la province de Grenville represente pour Ie Quebec une source importante et diversifiée de minéraux industriels. Le Ministère de l'Énergie et des Ressources du Québec, dans Ie cadre de I'entente auxiliaire Canada-Québec, et les compagnies minieres y ant multiplié, surtout depuis 1983, leurs travaux d 'exploration, de cartographie, et d'évaluation pour les minéraux industriels. Ces travaux ant conduit ala découverte et ala mise en valeur de gisements de granite architectural, de graphite, de dolomite et ant aussi permis de repertorier des gîtes et des indices prometteurs de wollastonite, de silice, de calcite. de dolomite, de silicates d'alumine et de terres rares. Les gisements récemment découverts sont actuellement exploités au sur Ie point de l'être et les gîtes et les indices les plus prometteurs ant été jalonnés.ABSTRACTSince the late 18oos, the Grenville Province in Québec has been an important and diversified source of industrial minerals. The Ministere de l'Énergie et des Ressources du Québec, under the Canada-Quebec Mineral Development Agreement, and the private sector have put an emphasis on exploration, mapping and evaluation programs in the Grenville Province for minerals, particularly since 1983. These programs have led to the discovery and the development of deposits such as architectural granite, graphite and dolomite, and have also led to inventories of occurrences and prospects of wollastonite, silica, calcite, dolomite, alumina silicates and rare earths. The deposits discovered lately are presently being quarried or will be in the near future. The most promising occurrences and prospects have been claimed."

Jan 1, 1990

By Frank Ittner

In this section it is proposed to discuss operating methods considered good practice under the various field conditions commonly encountered. Efficient field direction and types of equipment needed to meet transportation problems are considered only to the extent that the desire to produce the best possible records must sometimes give way to the factor of cost. As in all engineering projects, alternative possible methods of operation must be considered in the light of relative costs as well as of the quality of results obtained, Cost may be in the background of much that is done in the field operations, but only the effect on record quality will be considered here. Record quality at a particular shot point may vary with the various factors of spread character (relative positions of geophones and shot point), shot-hole depth, formations opposite position of shot, size of charge, the effect of repeat shots, surface geology and culture in the immediate vicinity of the geophones, recorder instrument characteristics, particularly filter.

Jan 1, 1940

By Frank Ittner

In this section it is proposed to discuss operating methods considered good practice under the various field conditions commonly encountered. Efficient field direction and types of equipment needed to meet transportation problems are considered only to the extent that the desire to produce the best possible records must sometimes give way to the factor of cost. As in all engineering projects, alternative possible methods of operation must be considered in the light of relative costs as well as of the quality of results obtained, Cost may be in the background of much that is done in the field operations, but only the effect on record quality will be considered here. Record quality at a particular shot point may vary with the various factors of spread character (relative positions of geophones and shot point), shot-hole depth, formations opposite position of shot, size of charge, the effect of repeat shots, surface geology and culture in the immediate vicinity of the geophones, recorder instrument characteristics, particularly filter.

Jan 1, 1940

By Lawrence E. Mannion

In southwest Wyoming lies buried the world's largest source of natural sodium carbonate, or soda ash. Perhaps a hundred billion tons of trona (sodium sesquicarbonate) are contained in ancient lake beds in the Green River basin'). There the Green River Formation encloses more than 40 extensive beds of trona. At least 25 of these exceed 3 feet (1 meter) in thickness and most of them are more than 300 square miles in extent. Five have been exposed in mines and lie between 800 and 1500 feet below the surface. Others lie at depths of from 400 to 3500 feet. Three companies have underground mines that supply trona to adjacent soda ash plants. These are the FMC Corporation, Allied Chemical Corporation, and Stauffer Chemical Company. A fourth, Texasgulf Corporation, has a mine under development. In 1974, annual soda ash capacity in the Green River area was approximately 4,300,000 tons, which requires the mining of about 7,500,000 tons of trona.

Jan 1, 1975

By W. R. Dengler, R. S. Brown

In 1974, Brunswick Mining and Smelting Corporation Limited started a 48 million dollar expansion programme at their property in Bathurst, New Brunswick. A portion of the expansion plans includes a 26 foot diameter 4,525 foot deep shaft, underground crusher and conveyor excavations and lower level access development. J. S. Redpath Limited was awarded the contract for the new shaft and associated rock work in May 1974. Brunswick Mining and Smelting Corporation Limited, a member of the Noranda Group, operate this 10,000 ton per day lead, zinc, copper plant with proven reserves in excess of 90 million tons. While most of the ore is provided by the underground operation at the Number 12 ore body, some tonnage is produced from the open pit at the Number 6 ore body. Long range plans indicate a phasing out of the open pit and an increase in production from the underground operation. Existing facilities at the underground mine could not provide additional tonnage, thus the requirement for a new shaft. (Figure 1) The new shaft will also provide access to ore below the 2,800 level which is currently the bottom level of the existing facility. The contract called for sinking a 26 foot inside diameter, nine compartment concrete shaft 4,525 feet deep (Figure 2). Station access and ramp development from existing workings would be required to the bottom of the new shaft. In addition, development work for new crushing and conveying facilities was needed simultaneous with the shaft sinking.

Jan 1, 1976

By L. C. Stilwell

The paper will place into perspective the contribution that platinum makes to the South African economy. It will use statistics from official sources, namely the Department of Minerals and Energy, the Department of Customs and Excise, the South African Reserve Bank and Statistics South Africa. Surprisingly few people are aware of these statistics, especially Supply and Usage tables, published by Statistics South Africa, and trade statistics, published by the Customs and Excise division of the South African Revenue Service. The paper will therefore contain a concise explanation of input-output tables and supply usage tables, as well as the derivation of gross domestic product and an outline of the System of National Accounts, of which Input-Output Tables and supply and usage tables are components. GDP is a commonly used, but poorly understood, measure of the wealth of an economy. The paper will explain the methods used by SSA to calculate this indicator and its place in the System of National Accounts (SNA). South Africa exports almost all its platinum production (87.5% in 2002). Exports are a final demand, as opposed to intermediate demand from secondary industries, and therefore do not enter the value-adding process, which is the essence of GDP. By definition, therefore, platinum on its own is not a major contributor to GDP. The platinum industry does, however, have an impact (known as the multiplier effect) on other sectors of the economy. The paper will explain the meaning and derivation of these multipliers, using a model based on an Inverse Leontief Matrix.

Jan 1, 2004

By G. R. Chaudhury

Many base metals, such as copper, lead and zinc, are commercially extracted by thermal processing of sulphide concentrates. However, owing to the depletion of high grade sulphide ore reserves and to environmental legislation, efforts have been in progress for some years to develop methods for the extraction of metals from lower-grade oxide ores and secondary resources, and there are now examples of commercial-scale operations.

Dec 1, 1995

By Lee Fergusson

"The primary features of ViroMine™ Technology are introduced and applications of ViroMine™ Technology to mine site remediation and the treatment of a variety of intractable waste-streams, including a technical discussion of acid neutralizing capacity, metals binding capacity and longterm stability of results. Outcomes from four applications at high-profile international mine sites are presented: 1) the superfund site at the Gilt Edge Mine, South Dakota, USA (four years of data on the treatment of acidity, TDS and metals such as Al, Co, Fe, Mn and Zn); 2) one of Australia’s most polluted sites at King River Delta in Tasmania (treatment of TAA and TPA, and metal and metalloid contaminants such as As, Cr and Hg); 3) The Aljustrel “Aqua Forte” mine site in Portugal (high acidity, metal and metalloid contaminants such as Al, As, Cu and Zn) and 4) the Ulsan Iron Ore Mine at Ulsan, South Korea (treatment of metal and metalloid contaminants such as As, Cd and Ni).IntroductionThe commercialisation of ViroMine™ Technology has resolved some of the most intractable pollution issues associated with historic mining ventures on a global scale and has facilitated the neutralisation of Acid Rock Drainage (ARD), remediation of acidic and metal contaminated impoundments (including tailings dams) and promoted revegetation on tailings deposits and waste rock dumps. ViroMine™ Technology also enables current mining ventures to manage effluent simply and efficiently to meet increasingly stringent environmental standards and is enabling the mining sector to reconceptualise the management of mine spoil. The abilities of ViroMine™ reagents to neutralise the actual and potential acidity of sulphidic mine spoil coupled with the ability to bind metal and metalloid contaminants into non-bio-available forms are the key features delivering environmental and economic benefits to the mining sector and the broader community. Results from four projects utilising ViroMine™ Technology are presented to highlight the suitability of ViroMine™ Technology to treat all forms sulphidic mining wastes. 37"

Jan 1, 2008