Search Documents

By Paul W. Richardson

"Introduction And AcknowledgmentsTHIS PAPER outlines the geology and discusses the geological problems of the Mindamar mine. It is impossible to acknowledge the contributions of ideas of all the geologists who have worked in the area. Among the more important contributors are K. DeP. Watson, W. S. James, B.S.W. Buffam, and L. J. Weeks, and John MacPherson, the resident geologist at the mine.A mineralogical and chemical study of the ore and country rock is being carried •on by Dr. Watson at the University of California, Los Angeles.General InformationThe Mindamar mine is on Cape Breton Island, forty miles south-west of Sydney (Figure 1). The nearest railway stations are at St. Peters, which is thirty-two miles southwest of the mine, and at Sydney. Good gravel-surfaced roads connect the mine to the railways.The mine is producing at the rate of 600 tons a day of ore containing zinc, lead, copper, and minor amounts of silver and gold. At the present time the mill feed averages 9 .per cent combined metals, of which zinc makes u:p 7 1per cent and lead and copper each 1 per cent.General GeologyThe ore being mined ,by Mindamar occurs in a shear zone parallel to a northeasterly striking, vertically dipping, series of rocks consisting of rhyolite tuff, rhyolite, minor more basic flow rocks, and diorite (Figure 2). In the vicinity of the mine, these rocks have been termed the Mine Series. They belong to the Bourinot group, which has been assigned by L. J. Weeks to the Middle Cambrian. At the latitude of the mine, the Bourinot group is bounded on the northwest by the Stirling fault and extends eastward for two miles."

Jan 1, 1953

By Louise Laverdure

The Canadian mining sector has to be innovative and invest in the development of sustainable mining technologies to maintain its international leadership. Natural Resources Canada (NRCan) collaborated with the Canada Mining Innovation Council (CMIC) to define the Green Mining Initiative (GMI) and in order to focus its R&D activities on industry and other stakeholders? needs. The GMI was launched in 2009 to spur innovation in the mining sector and further enhance its environmental performance. The initiative, led by CANMET- Mining and Mineral Sciences Laboratories (MMSL), takes a holistic approach looking at the entire mining life cycle, from design to closure and beyond, through four innovation and research pillars: ? Footprint Reduction, ? Innovation in Waste Management, ? Mine Closure and Rehabilitation, and ? Ecosystem Risk Management. The Canada Mining Innovation Council has also been creating a new initiative on Sustainable Mining, which will bring further focus to environmental aspects of mining, and engaging wide range of research providers to develop research programs complementary to GMI goals.

May 1, 2011

By K. Koyama

As a study to establish a new energy-saving copper recycling process, the copper deposition at a cathode and oxidation of copper(I) at an anode from ammoniacal alkaline solutions containing Cu(I) or Cu(II) were investigated in order to examine the feasibility of electrolysis in this solution.. The current efficiencies were greater than 95% in the current density range of 200 to 1000 A m-2. The current efficiency decreased with the increasing Cu(II) concentration and temperature. In the batch-type electrolysis at the anode, during the initial stage, the current efficiencies were 100%, and the anode potentials ranged from 0 to 0.15V vs. SHE at a current density of 100 A m-2. During the subsequent stage, the current efficiency decreased with time, and the anode potential was around 1.35V vs. SHE where oxygen evolution at the anode surface was observed. As a result, the present electrolytic method can be the core technology in the said copper recycling process.

Jan 1, 2007

By Burrows. A.

Temperature profiles in the lead smelter sinter bed at Xstrata Zinc Mount Isa sinter plant have been measured using a wireless temperature probe. Corresponding sinter samples have been collected for characterization. The sinter peak bed temperatures were found to be in the range of 1000 - 1200 °C. Microstructures and softening temperatures of these sinters have been characterised. Strong correlations have been observed between peak bed temperature and peak hood temperature, and between mean sinter softening temperature and peak bed temperature. It was found that higher peak bed temperature results in higher sinter softening temperature. For the feed material used in the trials, to obtain sinters with mean softening temperatures above 1050 °C, peak bed temperatures above 1130 °C are required. There appears to be a direct correlation between granule size distribution in the feed and peak bed temperature attained. High peak bed temperatures are observed in sinters with narrow granule size distribution.

Jan 1, 2008

By M. J. Young, C. A. Aird

"The Gem molybdenum prospect is situated at the head-waters of Clear creek, between the Fraser river and Harrison lake, about 30 miles north of• Harrison Hot Springs, B.C. Clear creek follows a deeply eroded fault zone southwesterly through the center of the claim group. Elevations range from 2,000 feet in the creek bed up the steep slopes flanking the creek to a height of 5,500 feet. The property lies within an area underlain by schists and gneisses which strike from north to west in a broad fold plunging steeply to the northeast. This metamorphic complex has been invaded by numerous bodies of grano-diorite, much of which is gneissic. A granite plug, roughly 2,400 by 4,000 feet in size, has intruded this broad fold just west of Clear creek and encloses a circular breccia pipe 1,500 feet in diameter. In the breccia pipe, fragments of metamorphic rocks, granite and quartz monzonite porphyry are firmly cemented in a matrix of quartz monzonite porphyry. All the above rocks are cut by numerous fractures filled by vuggy quartz veins, many of which contain molybdenite. Attentien was first drawn to the area by a quartz vein, 18 inches in width, known as the Gem vein, which consists of several laminated bands of quartz and molybdenite. Since 1964, exploration efforts have been directed toward attempting to outline a large, low-grade type of molybdenum deposit."

Jan 1, 1969

By Adrian White

Agenda Overview of pastefill at Kidd Mine Pipeline wear and the need to monitor Steel Loop monitoring Steel Borehole monitoring Monitoring pipe linings

May 1, 2013

By R. V. Hopper, M. E. Wilson, L. S. Trenholme

"The Company known as Rouyn Merger Mines, Limited, was formed in 1943 to take over the ownership of claims in Rouyn and Joannes townships formerly held by East Rouyn Mines, Limited, O'Neil Thompson Mines, Limited, and the Hosking-Cockeram Prospecting Syndicate. The NorandaSenneterre branch of the Canadian National railway passes in an approximately east-west direction through almost the entire length of the property. Since 1937, sixty-three diamond drill holes have been drilled from the surface to cross faults on the contact of the Timiskaming sediments with the Abitibi ( Keewatin) volcanics, along which ore has been found to occur. Late in 1945, the sinking of a 3-compartment inclined shaft in the andesite agglomerate beneath the ore zone was commenced. On January 17th, 1947, this shaft had a depth of 944 feet; cross-cuts have been driven north-northwest from the shaft at 150-foot intervals from depths of 200 to 800 feet on the shaft (Fig. 2).GEOLOGYThe western or East Rouyn part of the Rouyn Merger property in which ore is being mined adjoins the area owned by McWatters Gold Mines, Limited, on the east and is underlain by the eastern continuation of the McWatters formations. As at the McWatters, the rocks belong structurally to three areas: (1) the territory north of the Cadillac-Bouzan Lake fault, occupied almost wholly by Abitibi ( Keewatin) volcanics; (2) the area along the south boundary of the property, underlain by Timiskaming conglomerate and greywacke; and (3) the synclinal belt of McWatters volcanics and sediments between areas 1 and 2.1Bouzan fault of Hawley."

Jan 1, 1954

By S. Torres, J. Álvarez, R. Castillo, R. Fuentes, C. Sandoval, R. Parra, Myakalwar A. K., M. Velázquez, J. Yáñez, D. Sbarbaro

Rapid analytical assessment in copper mining industry is a limiting factor for operational purposes and for the improvement of processes. The present work aims to review the analytical assessment in the copper industry utilizing emerging spectrochemical techniques such as laser induced breakdown spectroscopy (LIBS) and UV-Vis-IR Hyperspectral Sensing. LIBS is a plasma based spectroscopic method where the sample surface is irradiated by high power laser. The light emitted from the plasma contains atomic -molecular spectral information and can be detected using a simple CCD based spectrometer. UV-Vis-IR Hyperspectral Sensing is produced by the reflection of light from the sample’s rough surface in all directions and it can be collected by using an ellipsoid or paraboloid mirror arrangement. The electromagnetic radiation emitted by the samples in the UV-Vis, NIR and MIR region can be used for molecular characterization. The spectrometer splits different wavelengths through a CCD arrangement in 2D spatial and spectral dimensions, thus a hyperspectral cube of data is generated. Chemometric techniques such as principal component analysis (PCA), K- nearest neighbors (KNN), support vector machine (SVM) among others, can be applied to LIBS and Hyperspectral data for better classification and quantification purposes in copper ores. Real- time determination of elemental and mineral species used for online processing control will help to achieve the copper industry 4.0. INTRODUCTION The demand for copper mineral resources is intensely growing with the increase in population, per capita GDP, the development of new technologies and the increase in global living standard. With the rise in consumption of copper, it is important to optimize mining and metallurgical processes tending to the copper industry 4.0 (Ge, Song, Ding, & Huang, 2017). The real-time analytical assessment in the mining and metallurgical processes is a crucial part for allowing the global improvement in mining industry. The features considered for better analytical assessment are the instrumental automation and interconnection, real time results, low cost, quality in terms of accuracy and precision. Furthermore, improving recovery (extraction), timing and quality of final products avoiding environmental impacts. Some elements such as Cu, Fe, Ag, Au, Mo, S, As, Pb, Zn are important to be determined in the process control. Additionally, rapid mineral identification of few species such as CuFeS2, Cu4FeS5, FeS2, CuS, Cu2S, MoS2, Cu3AsS4, FeAsS, among other can be challenging.

Jan 1, 2019

By A. Plugatyr, C. P. Baxter

"Bessemer matte iron content is a critical process parameter that needs to be closely monitored and controlled in order to achieve optimal Ni/Cu smelter returns. Current process control practices during Ni/Cu converting often rely on visual observations and typically involve matte sampling to confirm that target composition was reached. A high-level techno-economic analysis study was carried out to evaluate potential direct benefits of advanced process control during the final stages of Ni/Cu matte converting. The results indicate that the magnitude of direct benefits will largely depend on matte iron control practices already implemented as well as matte iron set point. Preliminary assessment suggests that under the assumptions used in this study, implementation of advanced process control can potentially result in additional revenues ranging from several hundreds of thousands to tens of millions of US dollars per year per converter producing about 200 tonnes of Bessemer matte per day based on Ni, Cu, and Co metal recoveries alone.INTRODUCTION Real-time measurement of molten metal elemental composition, arguably, remains one of the key unresolved issues impeding full automation and real-time optimization of pyrometallurgical operations in different industrial areas, including non-ferrous metals and ferro-alloys. In particular, current process control practices during Ni/Cu matte converting often rely on visual observations and typically involve matte sampling in order to confirm target matte composition. In addition to being time consuming, this approach relies heavily on operator experience and diligence, and, therefore, requires continuous performance and quality control efforts. For instance, the need to improve quality of the Bessemer matte (BM) at the Copper Cliff smelter has prompted an impressive staff engagement and training campaign that was carried out by Vale’s team in the late 2000’s (Zanini, Wong, & Cooke, 2012). This training exercise was executed to address the compounded effect of several operational challenges, namely demand for higher throughputs, changes in the feed concentrate composition, increased feed variability, loss of process knowledge and expertise due to retirement, as well as lack of a comprehensive approach to improving the overall performance of the flowsheet rather than meeting production targets for intermediate products. Although the campaign was very successful and has resulted in significant improvements in the Bessemer matte quality, it has also highlighted the need to move away from “the-art-of-converting” and develop analytical tools that would enable real-time process monitoring."

Jan 1, 2018

By Walker. P. W. A.

Abstract -The Riviera tungsten occurrence in the Cape Province of South Africa was discovered in October 1979 as a result of stream-sediment panned concentrate sampling. The Cape age granite and late Precambrian Malmesbury Group carbonates and chlorite schists which it intrudes and which host the mineralization are covered by between 10 m and 30 m of Tertiary/Recent alluvium and clay. The scheelite/powellite and molybdenite mineralization occurs in a greisenized granite cupola with an overprint of porphyry-type alteration as well as in minor skarns. The ore reserve is estimated to be 46 million tonnes at an average grade of 0.2160Jo W03 and 0.020% Mo. The deposit is uneconomic at current tungsten prices.

Jan 1, 1994

By Charles Tkaczuk

In order to remain competitive the mining industry must keep up with changes in technology. Many innovative technologies from the mining perspective are commonplace in other industries. A ?Global? review of technologies will often reveal existing technologies that can be innovatively applied in the mining industry. Industries, which are rife with proven solutions include, medicine, biotechnology, security, manufacturing, telecommunications, etc. This paper addresses the communications aspect of mining where greater productivity, lower costs and the ability to quickly react to mining related events is obtained through an increase in remote monitoring and operating control. A review of the communications systems in place globally reveals technologies that, with minimal modification, can be immediately applied to the mining environment. We discuss the concept, advantages and implementation of existing communications technology from an industry that is not usually associated with the mining industry. This technology will form the basis of a solid platform on which can be built a state-of-the-art process monitoring, control, and communication system. This lays the groundwork for providing one solution to the underground mining industry?s most difficult problem, establishing a reliable, maintainable and cost-effective underground bi-directional wired/wireless data, video and analog communications system. We need look no further than our own doorsteps to find such a solution. The cable that you see coming from the simple green or brown box on the boulevard into your home contains hundreds of television broadcast channels, FM radio channels and data channels. And if you have a set-top box, you are in control of it all. The Cable Television Broadcast Distribution System suppliers of today are at the leading edge of converging all the different methods of communications onto a common carrier, coaxial cable or fibre optic cable. There is no fundamental difference between providing a reliable communications network to a city/neighbourhood/home/personal computer than there is to a mining operation/underground level/equipment or person. The principle is the same. Only the application is different. Realizing this, we can capitalize on the efforts of other industrial sectors, to solve our communications problem. Where else can you find a solution to a problem that is mature, having been developed with the input of thousands of engineers, and having hundreds of millions of dollars spent on research and development, manufacturing, distribution, global presence and engineering support?

May 1, 2003

By Hasini Wijayaratne

Anode cover material, a mixture of crushed electrolyte and alumina, is a crucial part of an aluminium reduction cell because of its important role in maintaining overall heat balance. However, until recently little attention has been given to understanding or controlling its composition and quality. The thermal conductivity of anode cover material determines the extent of the heat loss from the top of the cell. This will change as a function of the granulometry and composition of the applied cover as well as over time as the cover material consolidates on top of the cell. The ability to measure or predict the thermal conductivity of fresh and ageing cover is an important tool for managing cell heat balance. Recent studies have shown that granulometry or more correctly, voidage is likely to be the predominant determinant of thermal conductivity of anode cover materials. We have developed equipment to measure the thermal conductivity of granular cover material and tested the relative importance of composition (ratio of alumina to crushed electrolyte) and granulometry/voidage on cover thermal conductivity. In general, our results confirm that granulometry is the dominating factor. Generally, high voidages contribute to lowering the thermal conductivity especially when particles are mostly fine. However the relationships between granulometry, voidage and thermal conductivity are complex due to the varying nature of heat transfer between particles. Aging of granular cover material occur during cell operation forming a consolidated crust due to exposure to heat and fumes over time. Structure and thermal behaviour of this consolidated crust is also important in understanding the overall properties of cover. This paper presents the outcomes of laboratory studies conducted in order to understand the thermochemical behaviour of anode cover material and in particular, the role of fines in anode covers mixtures.

Jan 1, 2011

By P. W. A. Mayer

"As the push toward the northern regions of Canada steadily increases to exploit the rich mineral reserves, interest is steadily rising in respect to accessibility and climatic conditions and the problems posed thereby. In twelve years of operation, the Iron Ore Company of Canada, and associated companies, have found, through advanced technology, ingenuity and, most of all. need, some of the answers to the running of a profitable year-round open-pit mining operation."

Jan 1, 1966

By Chuck Crowell

ISO Standards ?Provide Information to Address Commercial and Safety Needs for Standardization: ?Definitions and Terminology ?Test Methods ?Performance Criteria ?Conformity Assessment Process ?Developed by Global Experts ?Promote Global Harmonization

May 1, 2013

By D. A. Brown, C. Lowe

"Abstract -A multi-sensor (electromagnetics, magnetics, gamma-ray spectrometry, and VLF) geophysical survey was recently conducted in the Purcell Basin of southeastern British Columbia in an area encompassing the world-class Sullivan Sedex deposit. The purpose of the survey was to geophysically characterize the known mineral occurrences and to develop strategies to enhance future mineral exploration in the basin. Follow-up investigations of geology and measurements of rock physical properties helped constrain interpretations of the geophysical data sets.Despite extraction of more than 90% of the ore from the Sullivan deposit, it is clear that the mineralization there, as well as at other Sedex occurrences surveyed, is characterized by high conductivity values, strong bedrock conductors, and elevated magnetic anomaly values. The albite-sericite alteration which accompanies this mineralization yields high potassium and low thorium-potassium ratio values. Associated Moyie gabbro is characterized by low electrical conductivity and radioelement concentrations and by high magnetic anomaly values. The study has also aided exploration for other mineral deposit types including stratabound Cu-Ag, placer gold, vein and disseminated basemetal deposits. In addition, the geophysical data have helped constrain geological interpretations of the basin."

Jan 1, 1998

By M. Falutsu

"The PSI-200 is a rugged, innovative, and easy to install on-stream size analyzer. Its calibration is simple and can be done on-line, during operation. Two measurements are displayed on the panel, which are expressed as percent passing a selected size, or as any statistical diameter. These two measurements are given as two continuous 4-20 mA output signals. Operation alarms are displayed on the screen or are given as digital output signals.The PSI-200 has been used in various applications at Lakefield Research. Particle sizes ranging from 10 µm to 450 µm have been monitored successfully, with an accuracy of 1- 2%. Having the size measured continuously and reliably, optimum conditions have been established for the grinding circuit, resulting in a superior quality in pilot plant testing.INTRODUCTIONThe challenge of any operating plant is to optimize product quality, maximize throughput and minimize operating costs. The importance of particle size measurement at a grinding circuit is well recognized. Monitoring continuously the particle size and keeping the product as uniform as possible is crucial to the whole mill operation regardless of the nature of the operation.Various techniques and instruments have been developed over the years attempting to give reliable on-line size analysis data. The operating difficulties and the reliability of these equipment still present major drawbacks and none of them proved to be widely accepted.PSI-200 is a relatively new on-line analyzer. The operation is simple and of low cost and the maintenance required minimal. It measures particle size and it displays two parameters of the solids size distribution, either weight fraction of passing a certain size or any statistical diameter. Two analog outputs can be sent to a process control system and through a supervisory control loop the correct action can be taken to maintain the desired particle size (perhaps adjust the feed rate to the grinding mill)."

Jan 1, 1993

By Stéphane Chevrel

Non-energy raw materials are vital inputs for the EU?s economy and maintaining fair and undistorted access to these materials for EU industry and citizens is increasingly difficult. Within the EU, exploration and extraction have to face increased competition for different land uses and a highly regulated environment. While the EU is currently dependent on the importation of many metals, the overall potential for mining and quarrying in Europe is strong. In spite of this, the land area available for extraction in the EU is constantly decreasing, turning access to land into a key challenge for the extractive industry. The EOMINERS project aims at contributing to demonstrate how to improve the EU capacity in implementing new mining sites and their societal and environmental acceptability. The overall aim of EO-MINERS (Earth Observation for Monitoring and Observing Environmental and Societal Impacts of Mineral Resources Exploration and Exploitation) is to bring into play EO-based methods and tools to facilitate and improve interaction between the mineral extractive industry and the society in view of its sustainable development while improving its societal acceptability. EO offers a unique opportunity to collect necessary spatial parameters that play a key role for better assessments of mining-related environmental and societal impacts. It could enable the development of means to identify the site-specific environmental and societal footprints of mineral resource extraction and to determine their respective significance. This understanding of global and cumulative footprints along a causal chain is needed in order to target policy measures. In this way the expected reduction of environmental and societal footprints in the mining sector can be most effective for the environment and more cost-efficient for public authorities and commercial operators. The project first defined environmental, socio-economic, societal, and sustainable development indicators and criteria that can possibly be dealt with using EO techniques. After an analysis of policies related to the environmental and social footprint of mineral industries, project expertise and stakeholder interviews (national and on-site) as well as site investigations led to the establishment of a list of indicators to be monitored, either directly or indirectly, through accessible parameters. Development of EO-based monitoring tools is then carried out over three demonstration sites: the lignite open pit of Sokolov in Czech Republic, the Mpumalanga coalfield centred on the town of Emalahleni (previously Witbank) in South Africa, and the Makmal gold mine in Kyrgyzstan. From these developments, it is subsequently intended to contribute to the development of generic, standardised EO data integration schemes, in particular in view of characterising affected ecosystems, populations, and societies and prepare indisputable documents that will make the basis for a sound ?trialogue? between industry, governmental organisations, and stakeholders. This paper discusses results obtained after three years into the project, focusing on product development over the demonstration sites and their relevance to the observation and monitoring of environmental and societal footprints of the extractive industry.

Aug 1, 2013

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 Gunther F. Leichtle, James A. Finch, Colin A. Hardie, Cesar O. Gomez

"The recycling of wastepaper has become an important and common process worldwide. Techniques similar to those used in the mineral processing industry are used to produce high quality recycled fibers for use in newsprint. The mineral processing group at McGill University in conjunction with the Pulp and Paper industry (Mechanical and Chemi-mechanical Wood Pulp Network) has adapted one of these techniques, column flotation, for the purpose of deinking wastepaper. This article describes the typical process of recycling wastepaper from a mineral processing point of view. It also presents results from McGill University's flotation column test work at a Quebec wastepaper recycling facility.IntroductionThe recycling of wastepaper has become an important and common process worldwide, including Canada which is now the world's largest importer of wastepaper (CPPA, 1996). Much of the current drive to increase the utilization rate of recovered paper is a reaction to the solid-waste disposal problem that faces many Canadian and U.S. municipalities. The real problem in the disposal of solid waste is not the absolute amount of garbage that must be disposed of each year but this amount in relation to available disposal capacity.Environmental restrictions on the creation of new landfill sites and incinerators (the two main options for disposal of municipal solid waste) have tightened the demand/supply balance in the solid waste disposal market. This shrinking availability of waste disposal sites in the face of increasing population with greater disposal requirements defines the Developed World's solid waste crisis. Not only are there fewer disposal sites available, but the costs of using them is skyrocketing. These factors have increased government regulations mandating recycled paper content in newsprint. Conservation and environmental issues make the current drive for wastepaper recycling a real issue and business opportunity.A key to the success of producing quality recycled fibers from wastepaper is the deinking technology. The production of tissue papers, paper towels and newsprint requires regenerated fibers which are substantially free of ink particles. Of the various options available, mineral processing techniques can offer the most economical, environmentally acceptable and versatile strategies (Yoon, 1993). Today, it is recognized that flotation is one of the most effective processes for removing ink particles in the production of a high quality product. In a collaborative program with the Pulp and Paper industry, the mineral processing group at McGill University has adapted column flotation technology for this purpose. This article will describe the typical process of deinking from a mineral processing point of view (Part A). It will also present some results from McGill University's flotation column test work at a nearby paper recycling facility (Part 8)."

Jan 1, 1998

By D. T. A. Symons, M. M. Kapnistos

"Gravity profiles were established over five known Middle Silurian pinnacle reef s in Lambton County, southwestern Ontario. The profiles were approximately 3 km long, with stations every 60 m. Four fairly recent technological developments were used which now make the gravity method relatively efficient and inexpensive compared to the techniques available two decades ago. These are: (1) a La Coste-Romberg model G gravimeter to measure the gravitational attraction with a sensitivity of 0.01 mgal; (2) a Sokkisha model B-2 semiautomatic engineers level to measure the station elevations with an accuracy of 0.5 cm; (3) a Huntec FS-3 hammer reflection seismograph to determine the overburden thickness to an accuracy of ± 7%; and (4) a modern microcomputer to process the data sets and mathematically filter the gravity values. Thus, two men can measure and analyze approximately 1 km of profile per day and obtain the residual gravity profile to an accuracy of ± 0. 05 mgal. Positive gravity anomalies of 0.17 to 0.72 mgal were observed along all five profiles that approximately delineate the dimensions of the known pinnacle reefs, which have an average height of 120 m, diameter of 1500 m and depth to top of 575 m. The relative ease of the gravity survey method makes it a cost-effective technique for hydrocarbon exploration in southwestern Ontario. IntroductionPinnacle reefs are important sources of oil and gas. Although the pinnacle reefs in southwestern Ontario are small, they may contain commercial pools of oil and gas because of their proximity to refineries. They are also useful for subsurface storage of gas to meet the winter surge in gas demand.At present, geophysical exploration for new pinnacle reefs is done primarily by relatively expensive seismic methods, which are also limited in southwestern Ontario by prohibitions on blasting. Gravity methods of exploration were attempted more than two decades ago in this region. (Pohly, 1954); however, the level of technology at that time made the method marginal in sensitivity and quite expensive. Several subsequent developments- gravimeters with greater sensitivity and operating ease, ""self-levelling"" levels for elevation control, hammer seismic reflection units for determining overburden thickness and portable microcomputers for efficient data analysis-have significantly improved the precision and cost effectiveness of the gravity method. Five known pinnacle reefs were selected in Lambton County, southwestern Ontario (Fig. 1), to test the effectiveness of integrating these developments to locate and define additional reefs. Isolated reefs were chosen to avoid the problem of the gravity effect s of one reef interfering with those of a neighbouring reef. The surveys were facilitated by choosing reefs with a concession road passing directly over them ."

Jan 1, 1980