Search Documents

ABSTRACT Inco’s Iron Ore Recovery Plant was operated by Inco from 1955 to 1980 near Sudbury, Ontario. As exposures to specific nickel substances have been associated with adverse respiratory endpoints it is important to understand processes giving rise to such substances. This manuscript discusses the process and equipment, the propensity for aerosol formation, and operational procedures used by Inco in roasting a pyrrhotite concentrate, reducing the nickel in the formed oxide, leaching the nickel in ammoniacal solution, purifying the resulting solution, making green or black NiO, and producing iron oxide pellets. Industrial hygiene measurements are also reported.

Jan 1, 2013

By S. M. Chentouf, M. Jahazi, N. Bombardier, T. Belhadj

The main limiting factor in the commercial expansion of superplastic forming (SPF) of thin sheet aluminum alloys is the extent of cavitation phenomenon that takes place during the processing. The severity of the cavitation process is mainly dependent on the uniformity of deformation (i.e. level of local thinning) during processing. In the present paper, correlations are made between thickness variations in several formed sheets and the characteristics of the cavities observed in the material. The 1.4 mm thick 5083 aluminum alloy sheets were hot pre-formed at around 450°C for 4 min and then air-cooled. Opto-digital and Scanning Electron Microscopy were used to examine the microstructure and analyse the cavities. Also, grain size measurements were carried out for different location in the SPF formed piece. The surface and volume fractions of the cavities were measured with the aid of metallography image processing (MIPTM) on as-polished samples prior to etching. The results are analyzed in terms of the influence of applied strain and microstructure conditions on the propensity to cavitation of the alloy.

Jan 1, 2015

By M. Rebolledo, N. Mora, G. Zarate

For decades, the mining industry has been focussed to find an efficient and economically attractive process for the leaching of chalcopyrite. Jetti Resources has developed a novel hydrometallurgical alternative to extract metals of value from mineral ores that the mining industry has struggled to process. Jetti’s catalytic technology, whilst being especially advantaged for extracting copper from low-grade and highly refractory minerals, such as chalcopyrite, seamlessly integrates with existing heap leaching methods and downstream processing operations. The technology uses a catalyst which weakens the metal-sulfide bond in the crystalline structure of the chalcopyrite mineral and alters the structure of the passivation layer allowing the leaching process to continue. Metallurgical test work was conducted to examine the effect of ore variability, in terms of grade and copper deportment. The results presented in this study highlight the amenability of the technology and demonstrate that it is possible to enhance leaching performance of copper primary sulfides over a wide range of copper grades, from 0.1 to 2.2%. Further, it is concluded that despite the copper grade, the tests with increasing chalcopyrite content render copper recoveries up to 4 times higher compared to the tests under non-catalyzed conditions. Jetti’s catalytic technology is currently being evaluated at larger scales, namely a commercial dump leach operation and 50-tonne crib tests. The results obtained thus far are compared to the results from conventional sulfide heap leaching tests. INTRODUCTION For decades, the mining industry has been focussed to find an efficient and economically attractive process for the leaching of chalcopyrite. Chalcopyrite (CuFeS2) is the most abundant and recalcitrant of the copper sulfides (Singer, 2017). Owing to its abundance and economic importance, it is the most demandable natural source for copper worldwide. In fact, the projected demand for copper is further expected to rise much higher beyond the current demand by the year 2020 (Panda et al., 2015). Therefore, it becomes imperative to find low intensity hydrometallurgical technologies for the extraction of copper from chalcopyrite in ores of such low-grades that are un-economic to concentrate and to augment the supply by extracting copper from ores with complex mineralogy that cannot be concentrated (Watling, 2013).

Jan 1, 2019

By Osvaldo A. Bascur, Curt Heftier

The lack of integrated information including the Energy/Utility Suppliers with sufficient detail for analysis causes inefficient operation in metallurgical complexes including the Energy/Utility Suppliers . Defining the right context for information use is essential for sustainable operations. This being said, what are we doing to enable people to act upon information and to be aligned to optimize the use of resources like raw materials, energy, water and consumables for an entire metallurgical complex? Collaboration between all company entities is a key component of improving efficiency. Evolution of web technology and object modeling of enterprise assets enables collaboration across the whole business. Operational troubleshooting occurs more quickly as the organization acts on issues to reduce wasteful operation. This paper presents a real time software infrastructure with tools that give users the ability to sift through available data, transform data into information for business continuous improvement and optimization. We will introduce a new technology for analyzing real time data, information and events using multidimensional analysis of information to detect anomalies based on the statistics of the data classified by time events to reduce the information into action. A new paradigm for collaboration at a local and strategic level is proposed to enable the enterprise to become proactive in dealing with wasted time and products. Three examples from the industry will presented and their benefits highlighted.

Jan 1, 2011

By P. P. Andrieux

The recovery of the Zone G crown pillar, located between the bottom of the open pit and the top of the underground workings at the Raglan Katinniq Mine in Nunavik, started in the summer of 2008 and should be completed by the end of 2009. This article describes the rock mechanics-based approach implemented to design the recovery of this valuable block of ore. The stereophotography-based ShapeMetriX3D technique was first used to provide a comprehensive assessment of the various joint sets that comprised the pillar. Then, the statistical distributions obtained for the dip, dip direction, spacing and persistence of these sets were used in conjunction with the geometry of the large-scale faults present in the area to build and run a series of explicit rigid numerical models. Each of these models had a slightly different jointing geometry, randomly constructed from these statistical distributions. Incorporating in a properly formulated numerical model the variability of some of the input parameters has allowed the engineering team to assess in a rational and reliable manner the likelihood of success of the proposed mining method and sequence.

May 1, 2009

By J. Lovering, M. Allan

"INTRODUCTIONThe Afton Mines property is located 180 air miles east-northeast of Vancouver and nine miles west of Kamloops, a city of 60,000 people in south central British Columbia. The deposit is located adjacent to the Trans-Canada Highway at an elevation of 2,231 feet above sea level.Interest in the property dates back to 1898, when a 330 foot shaft was sunk on the Pothook claim immediately south of the existing operations. Since that time many companies and individuals have investigated the possibilities of the area but it was not until 1972 that Afton Mines Ltd. located a significant zone of copper mineralization. The feasibility study was completed in the period 1974-1975, by Teck Corporation Ltd., who control Afton through 50% direct ownership and 65% ownership of Isa Mines, who own a further 23%. Construction began in March, 1976. Ore production started in August, 1977, and the first ore was fed to the mill on December 8. This was the third mine to be brought into operation by Teck since 1975, the others being Newfoundland Zinc and Niobec.The orebody is a porphyry copper deposit which has undergone supergene alteration. It is 1,700 feet long in a west-northwest by east-southeast direction, 300 feet wide and dips at 55° to the south. The mineralization in the supergene zone, which accounts for two-thirds of the known deposit, is rather unusual in that the copper is present primarily as native copper and chalcocite. The grade is one percent with the distribution: 70% native, 25% chalcocite, and 5% chalcopyrite with bornite, covellite, and cuprite."

Jan 1, 1979

By J. Peterson, D. D. Tannant, J. Todd

"A review of blast designs and improved blasting practices at the EkatiTM diamond mine is presented along with the results of three blast-monitoring experiments. Blast monitoring was undertaken to investigate blast damage mechanisms in the mine’s well jointed rock mass. Rock mass damage caused by production, pre-shear and wall control blasts was measured. EkatiTM uses 270 mm holes for production blasting, and 165 mm holes loaded with a decoupled charge for pre-shearing. The production blasts are loaded with bulk emulsion/ANFO blends. The mine plan involves using 30 m double benches. A 30 m high pre-shear is drilled and blasted prior to the production blasting that is done with sequential 15 m benches. This paper summarizes the monitoring equipment and data gathered to date. IntroductionThe EkatiTM diamond mine is located about 300 km northeast of Yellowknife, Northwest Territories, Canada. The mine is a joint venture of BHP Diamonds Inc. (80%) and geologists Charles Fipke and Stewart Blusson (10% each). The EkatiTM mine is Canada’s first diamond mine and BHP is the operator. The mine is accessed by air and by a winter ice road.The first kimberlite pipe mined at EkatiTM is known as the Panda pipe. The Panda open pit mine will have a total depth of 315 m (Fig. 1), a width of about 600 m, and a 50° overall slope. Initial ore production is 9000 tonnes per day.This paper summarizes the pre-strip blasting and the evolution of the production and wall control blast designs from 1997 to 2000. The initial blast designs and the rationale behind subsequent changes that took place are presented along with the techniques currently in use.The paper also briefly presents an experiment done to measure the rock mass response to blasting. Three blasts were instrumented with geophones, gas pressure sensors and time domain reflectometry cables. A brief summary of the instrumentation and data gathered is included."

Jan 1, 2001

By Sylvie Brassard

Available information ?? InfoMine: mineral properties ?? Metals Economics Group: budgeted exploration expenses ?? MineScan: Canadian and American Mining Companies ?? Statistics Canada: Canadian Direct Investment Abroad, by Sector in the world OR all sectors by Country

May 1, 2008

By R. D. Brown

"An adequate level of R & 0 is crucial to achieve gains in productivity and to strengthen Canada' s position in an increasingly competitive world ." So stated Finance Minister Jean Chretien in his April 10, 1978 budget speech, on announcing a new measure designed to increase the productivity of Canadian industry and to assist in the creation of new technology. The effect of the new measure, which permits an income tax deduction of 150% of certain research and development (R & D ) expenditures , can reduce the after-tax cost of a marginal dollar 's worth of such expenditures to as little as 20 cents . This article discusses the income tax treatment of R& D expenditures in general, and describes in particular the income tax incentives which relate to R& D.

Jan 1, 1978

By S. Bastola, Y. P. Chugh

"This research determines shear strength and stiffness properties of bedding planes and joints in the roof strata rocks within 7.5 to 9 m (25-30 ft.) overlying the Illinois #6 coal seam (within the pressure arch zone). A shear test loading device was designed into a 1.334 kN (150 t) Forney Compression Loading Machine to perform direct shear tests in accordance with ASTM D5607-08 “Standard Test Method for Performing Laboratory Direct Shear Strength Tests of Rock Specimens under Constant Normal Force”. The data were used to determine peak and residual friction angles and the dilation angle. A total of 49 bedding plane samples were tested, out of which 46 (36 intact and 10 relatively weak and loose) samples passed QA/QC procedures in accordance to ASTM D5607. Samples from eight (8) different bedding planes- shale/limestone (SL), shale/sandstone (SSs), shale/bone (SB), laminated sandstone (LS), shale/shale (SS), bone/bone (BB), bone/limestone (BL), and limestone/limestone (LL) were tested. The number of samples tested for each bedding plane were: SL- 11, SSs- 8, SB- 5, BB- 4, LS- 6, SS- 9, BL- 1, and LL- 2. Peak and residual shear strength values at 2.75 MPa normal stress range 1.06 – 6.26 MPa and 0.82 MPa to 0.82 – 4.14 MPa, respectively. The average normal and shear stiffness values are about 11.98 GPa/m and 3.11 GPa/m. Dilation angles are low (<10?) and negative in some cases. Angle of sliding friction values range from 9? to 42?. Joint Roughness Coefficient (JRC) values were less than 10.INTRODUCTIONRock mass may be defined as the total in situ rock medium containing bedding planes, faults, joints, folds and other structural features. Therefore, it is discontinuous and may have heterogeneous and anisotropic engineering properties. Upon creation of an excavation in a rock mass, bedding planes and joints are the most likely points of failure initiation. The failure typically occurs either in tensile or shear mode. Upon failure initiation stresses are transferred to the neighboring rock mass and the failure progresses until stability is achieved through equilibrium of stresses and strength. An example of this mechanism is development of the pressure arch. This study determined the shear strength and stiffness properties in shear and compression of bedding planes and joints in the immediate roof strata rocks within 7.5-9 m ( 25-30 ft.) overlying the Illinois No. 6 coal seam (within the pressure arch zone). Since such data are currently not available for Illinois Coal Basin mines, researchers and engineers have been using estimated values for design purposes. The immediate roof lithology in the proposed mining area consists of shale 0.62 m; Bone 0.09 m (0.3 ft.); Limestone, 0.10 m (0.33 ft.); Shale 2.37 m (7.9 ft.); and sandstone 0.55 m (1.83 ft.). The bedding plane samples were provided by a mine in south-eastern Illinois operating at a depth of about 180 m (600 ft.)."

Jan 1, 2015

By H. C. M. Gordon

MR. A. D. BADOUX: I have listened to Mr. Gordon&apos;s excellent paper with great interest, as I personally have gone through some of the experi­ences he has so clearly depicted. In particular, there were a good many times when we were greatly exercised in our minds as to whether we were justified or not in closing-off certain sections in the Allan mine. The difficulty in these cases arose from the fact that a peculiar smell could be detected in these sections but at the same ti me there was no positive evidence of spontaneous combustion either from heat being apparent or from the possible indications of fire getting any worse. It was suspected that the small percentage of -carbon monoxide that could be obtained by analysis in the air in these sections, and also the peculiar odour, were emanating from the coal itself, and, in order to verify this, bore-holes were drilled in the coal and the gases released from these bore-holes were analyzed. They were found to contain carbon monoxide. After quite a considerable length of time this contained carbon monoxide gradually diminished and finally could not be detected when analyzing such samples of gas. It was our intention to follow this matter up further, as such an occurrence of carbon monoxide is practically unknown, but the sections in which these occurrences were found had to be abandoned. Mr. Gordon referred t0 a case of spontaneous combustion in the Allan . mine, and I may say that, although the section in which that occurrence took place was travelled and carefully examined every day by the colliery officials, yet nothing unusual was noticed until the fire actually took place. This tire was the cause of a slight explosion.

Jan 1, 1938

By Randolph R. Dreher, Michael L. Schreder

"In recent years, FFE Minerals has designed, installed and commissioned several large grinding mill circuits. This paper discusses the issues related to the erection and commissioning of large grinding mill circuits. The three circuits discussed are Collahuasi in Chile, Minera Los Pelambres in Chile, and Century Zinc in Australia. These circuits include large SAG and ball mills with both gear and gearless drive arrangements, as well as, both trunnion and shell supported mills. Aspects of these features are discussed with respect to their impact on installation and commissioning. While the normal challenges of mill erection and start-up were experienced, there were also a few unexpected challenges encountered partly due to the large scale of the equipment. An overview of the equipment and design ratings of these circuits is also provided.COLLAHUASIOverviewThe Collahuasi mills were started-up in November of 1998. The site is located in the Andes Mountains at an elevation of 4300 meters. The grinding circuit includes two lines featuring one SAG mill and one ball mill for each line. The circuit features a recycle conveyor around the SAG mills with provision for adding a pebble crusher in the future. The design tonnage of the grinding plant is 60,000 MTPD with an ore BWI of 10.5 kWh/MT.The SAG mills are 32’ x 15’ (1 3’ EGL) with 10,800 HP drives. The drive arrangements are dual pinion through pneumatic clutches. The mills are driven by low speed synchronous motors with CCV variable speed drives. The SAG mills are trunnion supported and use hydrostatic lubrication. Feed to the SAG mills is via a rock-box type feed chute on a cart. The mills discharge on to trommel screens with a bucket wheel to remove the oversize.The ball mills are 22’ x 36.5’ (36’ EGL) with 12,500 HP drives. The drive arrangements are dual pinion through pneumatic clutches. The fixed speed mills are driven by low speed synchronous motors with GE Quadramatic load sharing drives. The ball mills are shell-supported and feature multi-pad bearings with hydrodynamic lubrication. The mills are fed via a rubber lined sump box with feed spout on a cart. The ball mills also discharge on to trommel screens. Twenty-six inch (26”) diameter hydrocyclones are in closed circuit with the ball mills."

Jan 1, 2001

By John C. Robbins

A new technique for the determination of trace levels of uranium in solution has been developed. A compact laser emits short, but intense, ultraviolet pulses to excite the green fluorescence of a uranyl-complex formed by the addition of a proprietary reagent to the sample. Organic species present in most natural waters also fluoresce quite intensely, but their emission does not last appreciably longer than the excitation pulse, in contrast to the relatively long persistence of the uranyl fluorescence . Electronic &apos;gating&apos; is employed to separate the long-lived contribution, rejecting substantially the organic emission. Results using the laser fluorescence method on many sets of natural waters of various origins have been compared against corresponding values generated by independent laboratories. Correlation has been generally good over a range from less than 0.1 to more than 100 ppb U. Solid samples have also been analyzed after extraction of the uranium into solution. Accuracies adequate for most exploration purposes have been achieved, but further work is required to determine effects of interferences in samples with complex matrices. The transport and deposition of uranium in natural waters is controlled by the organic and inorganic chemistry of the waters involved. It is suggested that interpretation of very low uranium levels will be aided by additional measurements of conductivity and organic content, with subsequent statistical treatment.

Jan 1, 1978

By W. K. Gummer

"THE LOCATION of Canada's present aluminum industry is determined by availability of hydroelectric power, and ready access to ocean transport facilities. The chief raw material for the production of the metal is imported by ship over several thousand miles of water. In times of freedom of shipping and uncontested movement this provides the industry with its cheapest method of operation. However, during the early part of the last decade the general conditions of ocean and rail transportation were such that interest in the treatment of materials other than bauxite was greatly stimulated. This was the case not only in Canada, of course, but in most other countries.Canada has no deposits of bauxite and much research was carried out on other aluminous materials, chiefly silicates, in an effort to develop more or less economic and feasible methods of treatment. In the United States, this research was considerably more extensive. Some projects were early shown to be of little or no value, whereas others, including the widely publicized lime-sinter and soda-lime-sinter methods, became important. In North America, however, apart from the application of the sinter method to the hitherto waste-product (red mud) of the normal Bayer plant operation, none of these processes contributed appreciably to the production of aluminum during the war. In certain European countries, on the other hand, largely because of their situation with regard to bauxite deposits, they had a more general application, and Germany, for example, produced alumina from clay, ashes, and slag by at least four methods."

Jan 1, 1952

By A. H. Winckers

"The San Nicolás deposit is a complex fine grained polymetallic volcanogenic massive sulphide deposit located in central Mexico.Metallurgical testwork was carried out in 1999 and 2000 to develop a flowsheet. During the course of the metallurgical testwork it became evident that it would be impossible to develop an accurate head gradehecovery based model for the projection of metallurgy. It was suspected that variability in mineral texture was a predominate factor affecting metallurgy. For this reason it was decided to evaluate the applicability of QEM*SEM technology to this test program.This paper summarizes the metallurgical testwork and describes the evaluation and subsequent application of the QEM*SEM technology to characterize the mineral texture throughout the deposit. Finally it is shown how the QEM*SEM data are used in the mine block model to project the metallurgy.The QEM*SEM (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) is an automated image analysis system developed by CSRO which provides quantitative numerical estimates of the compositional and textural properties of the mineral suite which govern the concentration process.INTRODUCTIONThe San Nicolás deposit, was discovered in 1997 through the application of geological and geophysical techniques. The property lies 60 km southeast of the city of Zacatecas on the central Mexican plateau as shown in Figure 1."

Jan 1, 2002

By Ian M. F. Arnold

"Occupational health programs and their role in improving the quality of working life in the mining industry are discussed. Attention is directed to some problems peculiar to the Canadian mining industry. Factors affecting program development are reviewed, as well as parameters affecting cost-benefit analyses.IntroductionThe quality of working life in the mining industry is a more important consideration than in many other industrial environments because of the very nature of the undertaking. It was a strange paradox of the 1960s that preventive maintenance programs for machinery and equipment were well accepted, whereas the concept of ""preventive people medicine"" was basically ignored. Fortunately, there seems to be a swing toward the development of occupational health programs in many sectors of the business community; however, there is a noticeable lack of consistency and uniformity for thought among the members of the mining industry. The blame for this lack o f progress in the occupational field cannot be entirely attributed to the industry, but must also rest with (for the most part) apathetic and inadequately trained physicians. This latter problem is slowly improving with the growing recognition that a well-planned and executed occupational health program may improve the quality of working life for mining employees and their families.There are a number of factors which relate to occupational health in mining, and its effect on working life quality. Included among these are:1. Community isolation.2. High accident risks.3. Occupational disease risks.4. Production demands and the state of the economy.5. Government regulatory requirements.6. Travel demands.These, and others, reflect on all levels of the mining industry. To examine how these factors can be moderated by an occupational health program, it is necessary to first review the rationale for such a program and some of the costs related to it."

Jan 1, 1983

By K. W. Fritzsche

The prosperity of any nation depends, to a large extent, on its natural resources such as oil, coal, &apos;metal, timber, waterpower, and fertile soil. Each one of these resources forms the basis of a huge industry. The mining and smelting industry ranks among the first since it paves the way for a number of other industries. The mines and smelters provide a market for electric power, coal, timber, and agricultural products: other industries in turn provide a market for metals and non-metals. The real pioneering, however, is done by the prospector who goes into the wilderness to search for the ores from which the metals are to be extracted for the use of men. Prospecting is an interesting and fascinating occupation. There are many difficulties and hardships in the way but the lure of gold and the vision of finding an outcrop that may develop into a large bank account, within a reasonably short time, will urge the prospector forward. Thus, on the outskirts of this northern hemisphere hundreds of prospectors are searching and toiling and of whom nothing is known or heard until they reach civilization and announce a new discovery. Then a mad rush takes place and everybody who can afford to go will take a gamblers chance and plant stakes in the neighbourhood of the new discovery, or wherever an outcrop of mineralized rock can be found, with the hope of winning a fortune.

Jan 1, 1925

By J. M. Simard, S. Morissette, P. Coursol, P. Mackey

A new, powerful model is presented that focuses on plant logistics and scheduling aspects of the smelting, converting, fire refining and casting operations at the Horne smelter. This plant complex is the largest custom copper smelter in North America. It handles a wide range of feeds and utilizes a number of proprietary continuous and batch technologies that require good scheduling in order to maximize plant capacity and efficiency. The present model was developed by Xstrata Process Support, in collaboration with the Horne smelter, and uses the Arena® software to evaluate the impact of a number of plant variables on the annual copper capacity of the plant. Model development was carried out by Xstrata Process Support, in collaboration with the Horne smelter, through the effective combination of process chemistry knowledge and detailed knowledge of the plant operation (including all material flows and transfers, as well as information such as operating on-line times, plant stoppages and also scheduled and unscheduled maintenance activities). A number of case studies were then examined, including the impact of anode furnace and casting cycle times on annual copper capacity and the impact of a one-crane mode of operation in the converter aisle, which normally operates with two cranes in service. The model predictions were found to match actual plant results very well. The present modelling of plant logistics and the scheduling aspects were found to add important dimensions at the plant with regard to projections of the real-life plant capacity. As demonstrated in the present case, this type of model and application can have a significant impact on optimizing operations at a given plant. This impact is particularly important in the current market environment, where emphasis is on maximizing plant output and lowering costs. These models can help yield the easily obtained gains that are clearly desirable in these times. Xstrata Process Support has developed Arena models for other operations and is available to explore new applications for a win-win situation at other plants, including mines and concentrator operations.

Jan 1, 2009

By Qingxia Liu, Mingbo Zhang, Hongbo Zeng

The shortage of freshwater has been a major challenge for mineral flotation in arid areas. When using high salinity water, certain electrolytes are detrimental to flotation while others can improve the flotability of minerals. In this paper, the flotation behaviors and contact angles of pyrite in both Milli-Q water and high salinity water were investigated using different collectors at various pH levels. Results show that the thionocarbamate has a less affinity to pyrite in different solutions under mildly alkaline conditions as compared with potassium amyl xanthate (PAX) and N-isopropoxypropyl-N’-ethoxycarbonyl thiourea (iPOPECTU). At high pH levels, the slime coating on pyrite surfaces, which is caused by colloidal precipitates of magnesium and calcium ions in seawater, was confirmed by SEM, EDX and in-situ zeta potential measurement. The slime coating of colloidal precipitates on mineral surfaces led to low recovery of pyrite at high pH levels. The study of flotation behavior of pyrite in high salinity water improves our fundamental understanding of mineral flotation in seawater.

Jan 1, 2015

By Neil Campbell

"The gently-dipping Devonian dolomite beds south of Great Slave lake in northern Canada are nearly every-where concealed by a cover of glacial drift and muskeg. Nevertheless, in 1898 or earlier, four small outcropping areas of dolomite, richly mineralized with lead and zinc sulphides, were discovered. Exploration work performed here up to the end of 1930, included intensive trenching and drilling of the showings, together with mapping and wide-spaced drilling in the surrounding region. This work proved that the discoveries are isolated pockets of mineralization much too small to be commercially valuable by themselves. No evidence of orebodies elsewhere was reported.Meanwhile, mapping by the G.S.C. in the Shield far to the east disclosed major Precambrian faults, some of which can be projected southwesterly (under a cover of Paleozoic sediments) to the vicinity of Pine Point. During the period from 1940 to 1947, consideration was given, by The Consolidated Mining and Smelting Company Ltd., to evidence of a theoretical possibility that, although apparently dormant in Paleozoic times, these faults may have provided a structural control and a source of ore-bearing solutions in some post-Devonian period. From this, it was postulated that the breaks might have created, in the overlying dolomite, a linear array of orebodies concealed by overburden but lying in a belt of considerable length and in a position predictable within practical limits. A program of drilling designed to test and exploit this specific concept was conducted from 1948 to 1955.he drilling within the new, theoretically-defined search area resulted in the discovery of many lead-zinc ore-bodies, none of which was exposed at the surface. Some of these are large and (as indicated by 1965 production records) very rich. They are situated 1 to several miles distant from, and apparently not connected to, the earlier-known surface discoveries. The drilling also disclosed that the ore, which consists of disseminated sphalerite and galena replacements together with colloform sphalerite and coarse galena cavity fillings, occurs mainly at certain stratigraphic horizons within a large, coarsely-recrystallized dolomite barrier reef. Considerable fracturing and folding was found. It has been suggested that reef development was influenced by post-Precambrian tectonic movements associated with the old faults in the basement complex. The ore may have been deposited by solutions moving from distant sources to favourable structural and chemical environments in or related to the reef.In more recent exploration performed in the course of preparing for mining production, the rate of ore discovery within the same general geological context has been greatly accelerated by the use of new geophysical techniques and drilling equipment. Reserves of 21.5 million tons, averaging 4 per cent lead and 7.2 per cent zinc, were reported in 1965, and production from open pits at the rate of approximately 248,000 tons of concentrates per year is in progress"

Jan 1, 1966