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By F. Daniel Rosenkranz, Peter L. Silveston

Experiments investigating the treatment of a ground wood white water waste from an Ontario pulp and paper mill by an HVCB coal are reported. Adsorption capacity for the waste, with a soluble COD contribution of 2,100 mg/I, amounted to 0.17 per cent, by weight, of the Nova Scotia coal used. Percolation of the white water waste through a coal bed indicated that soluble COD is removed. For finely ground coals, over 90 per cent of the suspended solids in the waste are retained on the coal. Plugging of the coal bed is rapid, so that any treating process using filtration would have to renew the surface of the bed frequently.

Jan 1, 1970

By A. M. Cameron

THE HOISTING PLANT at the Stobie section of the FroodStobie mine is a two-shaft installation designed to handle a daily production of 18,000 tons of ore at depth. The two vertical shafts are within 100 feet of -each other, an arrangement made to provide the needed capacity and to give flexibility of operation (Figure 1). No. 7 shaft, used for handling men and supplies as well as for hoisting ore, has been sunk to the 3000 level and is served by a manhoist handling two cages and an orehoist with two 14-ton capacity Kimberley skips. No. 8 shaft, so far completed to a depth of 1,900 feet, handles only ore. The hoist is semiautomatic with push-button control and the skips are 15-ton capacity bottom-dump. The ore-loading pocket for first stage hoisting at both shafts is 120 feet below 1,600 lev-el and additional pockets are planned, as the shafts are deepened, at 800 foot intervals down to 4,000 feet.

Jan 1, 1956

By G. Harper

"AbstractThe Suetut. Copper deposit, 230 miles northwest of Prince George, B.C., was discovered in August of 1971. Subsequent exploration has included 56,417 feet of surface diamond drilling in 139 holes. The deposit occur in gently dipping volcanic rocks of the Upper Triassic Takla Group, which out crops as rugged mountains.The general Mesozoic sequence comprises some 20,000 feet of green and red basaltic to andesitic rocks. The Lower Formation is characterized by subaqueous basalt, andesite and augite porphyry flows with interbedded breccias. They were rapidly deposited in tectonic depressions of limited extent and steep gradients. Facies changes are abundant. The Middle Formation. consists of volcaniclastic rocks made up of fragments from the underlying formation. Two cycles are discernible , both with basal turbiditic, tuffaceous sandstone and shale units overlain by massive, volcanic conglomerates exhibiting graded and cross bedding. A broader, shallower-water basin is indicated. The top of the uppermost unit was subaerially deposited. The Upper Formation is a variable sequence of volcanic sedimentary rocks. Detritus was supplied from a wide source area and included multiple reworked fragments of the lower formations and material from other rock groups known in the region. Zeolite facies metamorphism is recognized throughout: the entire sequence. Epidote is particularly abundant in the Middle Formation, demonstrating the results of metasomatism.The mineralized zone is approximately concordant with the strata over 100-200 feet of the Middle Formation succession . It lies just below the zone of transition from subaqueous to subaerial deposition in the top unit. Hematite, chalcocite, pyrite, bornite, chalcopyrite and native copper are disseminated throughout all sizes of lithic fragments and matrix. Concentration into the specific zone is believed to be due to upward leaching of copper during lowgrade metamorphic and metasomatic reaction. Precipitation occurred in the zone of hydration characterized by prehnite-pumpellyite below the oxidized subaerial rocks."

Jan 1, 1977

"The Cooperative Research Centre for Mining Technology and Equipment (CMTE) is funded by the Commonwealth Government, by its mining research members — the Universities of Queensland and Sydney and the CSIRO1, and by its industry members — BHP Coal, RioTinto R&TD, Hamersley Iron, Mining Technologies Australia, Pasminco, Shell Coal, WMC Resources, Advanced Mining Technologies, and Aberfoyle. The Centre conducts work aimed at improving the competitiveness of the Australian mining industry. The current work is focused in four areas: new mining and drilling systems, geological sensing, automation, and equipment maintenance and reliability. This paper describes much of the work in these program areas that relates to metalliferous mining. Mechanized Rock ExcavationThe disadvantages of the drill-and-blast excavation method are widely recognized and the last half of the 20th century has seen mining companies and mining research organizations aggressively pursue technology to excavate rock by other means. As discussed below, despite considerable effort and large amounts of funding, the quest for mining’s “Holy Grail” has been unsuccessful in all but the weakest rock types.COMRO (the Chamber of Mines Research Organisation) supported by the South African gold mining industry, spent three decades and (probably) tens of millions of dollars developing prototype drag bits and, later, impact breaking machines aimed at the mechanized stoping of narrow, tabular reefs. This work has not yet produced a commercially-attractive mining system. Work continues in South Africa to mechanize these stoping operations although now the emphasis is on the use of diamond-wire sawing techniques. This work remains in the experimental phase.Both British Coal and Germany’s Bergbau- Forschung spent many years developing techniques trying to extend the range of rock types which roadheaders could cut economically. Again, although new knowledge was produced, it is difficult to claim that any new commercial mining systems emerged from this work."

Jan 1, 2001

By A R. Bullis

Metal Mines Limited (Bancroft Division) was incorporated m 1964 to take over the assets of Faraday Uranium Mines Ltd., including their uranium deposit near Bancroft. Ontario. This paper outlines the geology of the Bancroft area, and. then go on to describe the principle rock types m the mine workings, especially the pegmatite, which is the host rock for the uranium mineralization. The structure and mineralogy of the orebodies are thoroughly covered, and, after a summary of the production and ore re-serve figures, the paper concludes with suggestions for further exploration work. Location and History M ETAL Mines Limited, Bancroft Division, is located in Faraday township, Hastings county, Ontario. The main production shaft and concentrator are about: Y2 mile north of Highway 28 and about 5 miles west of the village of Bancroft (Figure 1). The presence of radioactive minerals in the Ban-croft-Wilberforce area has been known since the early 1920's. Uraninite was found at the Richardson deposit near Wilberforce in 1922, and some attempts were made to produce radium from the deposits of the area between 1929 and 1931.

Jan 1, 1965

By P. Bramwell, R. Tremblay

"The Port Radium leaching plant of Eldorado Mining and Refining, Limited, produces 450 t./d. of sulphuric acid leach liquor containing l. 73 g. /I. U 308. After solvent extraction, the waste solution is discarded at 0.002 g./l. U30s for a recovery of 99.8 to 99.9 per cent. The solvent is acidified with weak sulphuric acid, loaded to 4.5 g./l. U80:1 in three-stage extraction, scrubbed with water, and stripped with soda-ash solution in single-stage stripping. Caustic removes the UaOs from the pregnant strip solution as a precipitate. The slurry is filtered, re-pulped with water, and re-filtered. The pressed precipitate at 81 to 82 per cent equivalent U30s is dried and packaged. The carbon-ate filtrate is cooled to remove sodium sulphate build-up and carbonated to convert excess caustic. Reagent consumptions are 4.1, 0.22, and 0.39 pounds per 1,000 gallons of pregnant solution for Diesel oil, amine, and alcohol, respectively. Caustic consumption averages 1.3 to 1.4 pounds per pound U3O8.Extraction and stripping is accomplished in sheet-iron mixer-settlers lined with Phenoline. Piping on both circuits is Schedule 80 polyvinyl chloride. Valves are straightway Buna N lined with American Hycar diaphagms. Extensive instrumentation ensures good metallurgy with a minimum of variations and labour. Mixing in a continuous organic medium and careful acidity control are required to minimize third-phase formations. Heating the precipitate slurry is conducive to good filtering in Perrin presses with neoprene-coated, rolled-steel sectors. Sodium sulphate is crystallized from carbonate filtrate solution by batchwise cooling to 54°F. with lake water."

Jan 1, 1959

By Jas. G. Ross

Introduction Asbestos, a mineral known and used in ancient times, has become an article of commerce only during the life of the older asbestos miners in Quebec. The diversified uses of this adaptable substance are now numbered by the hundreds. Wherever insulation or resistance to heat may be required, asbestos, either by itself or mixed with some other material, may be employed to advantage. Regarded as a curiosity for centuries, it is now in such common use that it is familiar to all. The demand for long fibre for use in the manufacture of textiles and brake-lining, and for shorter fibre for making shingles, paper, and insulation materials, serves to support the industry of mining asbestos-bearing rock and milling the fibre from it in Canada, South Africa, Russia, Cyprus, and the United States. The commercial use of asbestos dates only from 1876, in which year large deposits were discovered in the Province of Quebec, Canada. Prior to that year a small amount of long fibre amphibole asbestos was produced in Italy. Occurrence In Canada In the Eastern Townships of Quebec, along the line of the Quebec Central railway, is an area of serpentine rock. It extends westerly into Vermont and easterly to Gaspe. A part of it, the section from Danville to East Broughton, contains areas in which occur deposits of commercial asbestos fibre of the chrysotile variety. Pits have been opened on some of these deposits at Danville, Coleraine, Black Lake, Thetford Mines, Robertson, and East Broughton. Thetford is distant 68 miles from Quebec city, East Broughton lies 25 miles to the northeast of Thetford, while Danville is 45 miles to the southwest of Thetford.

Jan 1, 1927

By J. -C. Parisien-La Salle, D. Blais, G. P. Demopoulos

"In this work the dissolution, precipitation and adsorption behaviour of gold in acidic iron sulphate media containing small amounts of chloride ions is investigated via batch laboratory tests and OLI thermodynamic calculations over the temperature range 25-250°C. Chloride ions may be present in industrial pressure oxidation/pressure leaching (POX/PL) operations due to elevated water salinity levels or due to intentional addition as is the case of the CESL Copper Pressure Leaching Process. Thermodynamic calculations show that AuCl4 - may form depending on the free Cl-/Au ratio and temperature, its stability increasing with increasing Cl- concentration and decreasing with increasing temperature. On the other hand during POX/PL, we know that massive precipitation of iron in various hydrolysis products and compounds occurs. Hence of interest is the question how AuCl4 - that may form during leaching interacts with the iron precipitation products. Gold(III) chloride was found to co-precipitate with iron(III) (oxy) hydroxides and arsenates forming in the autoclave but not with natrojarosite. Upon further investigation it was discovered that activated carbon added in the autoclave (as done in CIL) acts as preferential sink for the mobilized gold, hence opening the potential for the development of a direct cyanide-free gold recovery process in acidic sulphate leach reactors.INTRODUCTIONThe recovery of gold from ores and concentrates has evolved over the years with processing routes becoming increasingly complex. Given the high value of gold, any reduction in losses during recovery operations constitutes an important economic benefit. One such loss that needs to be addressed is the potential solubilisation of gold during pressure oxidation (POX) of refractory sulphidic gold feedstocks. For example, Agnico Eagle Mines reported a loss in gold recovery due to the formation of a gold chloride complex (Garofalo, 2009). Gold is known to form complexes in solution, such as gold(III) chloride, if an excess of chloride ions are present. The fate of such soluble gold chloride during pressure oxidation and the subsequent neutralization of the acidic discharge slurry will determine if gold is lost or recovered in the downstream cyanidation operation. Thus it is of interest to know under what conditions gold chloride may stay soluble or co-precipitate along primary (formed in the autoclave) or secondary (formed during neutralization) precipitates. Furthermore, the mode of co-precipitated gold, such as adsorption on iron compounds, like goethite and hematite (Machesky et al., 1990; Nachayev, 1984); substitution in one of the precipitated phases; or finally chemical reduction to metallic state would have consequences in terms of gold recovery."

Jan 1, 2012

By H. L. Snyder

This paper outlines the approach to the underground construction work involved in the Churchill Falls Power Project. It is the first in a series of papers which CIM Bulletin plans to publish as the different 11hases of this large-scale operation evolve.

Jan 1, 1968

By D. Harrington

Ventilation of underground workings consists in establishment of such control of air currents that the underground workers may work in safety, with maximum comfort and efficiency, and without impairment of health; and requires that the mine openings may be made subject to such control of air flow as to remove from these workings at ordinary times harmful gases and dusts, and that, at time of emergency, such as fire or explosion, there may be maintained as much or as little air flow as may be desired covering portions of the mine or the mine in its entirety. Control of air flow is the keystone of any ventilating structure, and this very essential feature is obtainable only by the installation of mechanically-operated fans, together with other;. ventilating devices such as doors, over-casts, regulators, etc. Every mine, large or small, coal or metal, should from the outset be equipped with a fan. While much has been written about natural ventilation and many claims made that in specific mines there is sufficient natural air flow, there are few if any mines, coal or metal, where natural ventilation supplies anything like adequately safe or healthful conditions for underground workers even at ordinary times; and at a time of mine fire or explosion, mines depending upon natural ventilation are practically helpless, and certainly are decidedly dangerous to those unfortunates forced to be in them. While ventilation has practically always been deemed an integral part of coal mining, metal mines have rarely paid much, if any, attention to air circulation until forced to do so by occurrence of some untoward condition or accident. Yet metal mines actually have as great need of efficient circulation of air as have coal mines. The coal mine must remove the dangerous explosive gas, methane, also fumes from explosives and, in occasional places, other gases such as carbon dioxide or nitrogen.

Jan 1, 1933

By John Gittins

Lots 11 and 12, Range IX, Calumet island, are underlain by a Grenville metamorphic complex into which sills of tourmaline granite pegmatite have been injected. The pegmatite has an average mode-potash feldspar 65 per cent, sodic plagicdase 10 to 20 per cent, quartz 5 to 20 per cent, tourmaline 10 to 15 per cent, accessory minerals < 5 per cent; it is unzoned except for a narrow border zone. Some of the feldspar has been replaced by calcite. Microcline has been ?partially replaced by sodic plagioclase. Three varieties of tourmaline are present (black, blue, and green) and spectrographic analysis suggests progressive compositional changes during its crystallization. The presence of U- and Th-bearing minerals in the pegmatite prompted the Quebec Nickel Cor,porat10n, Ltd., to explore the possibility of developing the pegmatite but it does not appear that this is economically possible at the ? present time. Tt\e Grenville metamorphic complex consists of recrystallized limestones and calcsilicate rocks of the albite-epidoteamphibolite facies and the amphibolite facies, which were derived from sedimentary rocks. Several of these are dis-equilibrium assemblages, and retrograde metamorphism has probably formed biotite and epidote from hornblende. The schistosity of the gneisses dips steeply eastward. Numerous strike faults are roughly parallel to the schistosity and one of the pegmatite sills is bounded by such a fault, dipping at 60 ° with about one foot of fault breccia. The general structure of the map-area seems to be an asymmetrical syncline ?overturned to the west. The emplacement of the pegmatite is associated with a period of folding, metamorphism, and igneous intrusion.

Jan 1, 1956

By J. Talja

"Non-ferrous metal concentrates contain typically 7 – 12% water when received at the smelter. Removal of this water prior to smelting is always economically feasible because unnecessary heating of vapour (from 100 °C to 1200 °C) in the smelting furnace can thus be eliminated. This results in major reduction in CO2 emission and direct annual savings of several millions of dollars due to improved energy efficiency. Next step to further improve the energy efficiency, to gain substantial savings and simultaneously cut emissions is to select modern technology for the drying process. Consequently, all CO2 emission will be completely eliminated (from 40,000 tpy down to 0 tpy), NOx emission will be negligible, and the SO2 emission will be reduced by over 99 %. Switching of conventional direct heated drying technology to modern indirect steam drying brings, in addition to dramatic emission reduction, additional savings due to further improved energy efficiency. Direct energy savings count for 900 – 1300 MJ/t H2O, which depending on the concentrate feed rate and its moisture load can be worth several millions of dollars every year. Additional savings in operational expenses related to drying and gas cleaning may be worth a few million dollars more. Sustainability is a key issue today, and major savings together with significant emission reduction are readily available by proper technology selection for concentrate drying. INTRODUCTIONSustainability is a decisive principle in any process industry accompanied with emissions and high amount of energy. This is of significant importance in metal processing, including concentrate drying, where minimum impact on the environment, people and community are targeted, and all this with minimum cost, effort and resources. Therefore, special attention is paid to high energy efficiency, low energy consumption with preferable utilization of waste energy, safety issues, availability, level of maintenance, cost of maintenance, and emissions among other things.Non-ferrous metal concentrates can be dried using various techniques. Conventional drying based on direct heating, and use of fossil fuels for drying energy has almost entirely been replaced by steam drying. It is based on indirect heating and it has become the most dominant drying technology for copper concentrates during the last decade with over 90% of the market share of all new dryer installations. Among the steam dryers the Kumera Steam Dryer is the most pre-dominant technology with some 70% of all new dryer installations world-wide."

Jan 1, 2012

By A. W. Davis

Sapping and mining have constituted an important part of siege operations ever since powder came into general use in Europe. Before this period, famine was the main weapon in the hands of the besiegers, and the history of the middle ages is replete with accounts of sieges lasting two and three years. With the advent of explosives, a position impregnable to assault might be readily won by mining under, and blowing up, its defences. The natural offensive against this method of attack is to countermine and stop the attackers underground before their objective is reached. Thus developed the art of military mining. The French and British, in the Peninsular war, were adepts at this method of warfare, and the explosion of a mine and the formation of a breach were the usual preludes to the general assault of a position. In the Crimea, at Sebastopol, the British and Russians did a lot of underground fighting, as the old maps of their galleries, now in the museum at Chatham, will testify. In the siege of Port Arthur, in still later times, the Japanese and Russians were hard at it as well.

Jan 1, 1926

By T. Orser

In 2010 Newmont made the decision to purchase a 42 foot (ft) Semi-Autogenous Grinding (SAG) mill from Metso and a 28 Mega-Watt (MW) Gearless Mill Drive (GMD) from ABB for the Conga Project in Peru. The test and study work showed that a single line 42 ft SAG mill circuit gave the most favorable project economics in comparison to an equivalently powered single line 40 ft SAG mill circuit. This paper does not address the process design or the project economics, but instead focuses on the key aspects of the SAG mill design, GMD design and the associated component manufacturing. This paper also addresses, where applicable, the potential reliability differences between the initially proposed 40 ft SAG mill and the finally accepted 42 ft SAG mill.

Jan 1, 2012

By Adrian Dance

Newmont Ghana Gold Limited?s Ahafo operation have been working with Metso Process Technology & Innovation (PTI) since early 2009 to increase mill throughput from a combination of controlled blasting practices and optimised primary crusher and grinding circuit conditions. For such Mineto- Mill projects, PTI?s methodology is termed Process Integration & Optimisation (PIO). Ahafo operate a SAG mill, ball mill and pebble crusher (SABC) circuit that processes a range of primary ore of varying hardness from different pits which is blended with soft oxide material. The PTI study focussed on ball mill limited material from the Apensu open pit. Following a benchmarking study of all blasting, crushing and grinding practices in January 2009, PTI recommended changes in both blasting and crushing conditions in order to generate a finer feed size to the SAG mill. Additional operating changes in the grinding circuit were recommended. A series of trials were conducted in November 2009 where three blasts were fired using a different blast design (hole diameter and explosive type) in the same area of the Apensu pit as the benchmarked material in January 2009. Top and bottom benches (or flitches) from each blast were sent exclusively to the grinding circuit and the material was tracked using PTI?s SmartTag? system. The results from the six trials showed a significant increase in primary ore throughput at a reduced blend of oxide material. Ahafo have since standardised on these modified blasting conditions for all Apensu ore zones and have been able to sustain higher throughput compared to historical performance on similar material. This paper summarises the phases of the PIO project, the changes made in operating practices and the outcomes of the blasting trials that validated the predicted increase in mill throughput.

Jan 1, 2012

By G. H. McKay

AT the Eagle mine, near Gilman, Colorado, where the Empire Zinc Company have installed an underground mill, transportation problems were comparatively simple. A railway siding on the Denver and Rio Grande railway is equipped with an unloading dock or platform at the portal of their service incline adit to the mill. This 18-degree incline is approximately 600 feet long from the unloading track to the head of the mill skipway. For the Big Missouri mill, upwards of 2,500 tons of material and equipment had to be trucked from tidewater at Stewart, B.C., a distance of 21 miles to the Big Missouri camp at elevation 2,800. From that point, this freight had to be moved either over or through the Big Missouri ridge, rising to elevation 3,450, to its final location 800 feet from the surface between elevations 2,150 and 2,350. Immediately after leaving the government dock at Stewart, the road crosses the International boundary line into Hyder, Alaska, and then follows a water grade for eleven miles along the lower stretches of the Salmon river. leaving the river, the road climbs for two miles before crossing back into British Columbia territory at Silver Heights, and then continues for another mile and a half to where the Big Missouri road branches off from the main road to the Premier mine. For a distance of four miles from the junction of the roads, the Missouri road is very narrow, with many sharp curves and with irregular up and down pitches and grades up to 25 per cent until it reaches the Summit. From there on, a fairly easy grade leads a mile and a half to the end of the road on Joker Plats. In winter, the last stretch of road is subject to heavy snow drifting, especially through a narrow funnel-shaped gulch, known as &apos;The Gap&apos;, where the snow may pile up to a depth of over twenty feet.

Jan 1, 1938

By G. A. Brown

"Mining executives are becoming increasingly involved with decisions of the ""What would happen if ... "" variety. Potential changes in government policy, such as tax incentives, E.G.M.A. allowances, etc. affect the economic future of present and proposed mining ventures.This paper will discuss various measures of effectiveness normally used in assessing this future, such as discounted cash flow, etc., and will describe means of introducing uncertainty into the computations. As the recognition of risk and attitudes toward accepting it are very important in the life of a mine executive, there will be a brief discussion of utility theory and its application to risk analysis.Risk models are usually of a size to warrant the use of an electronic computer. Therefore, to demonstrate the simple interaction necessary between a financial analyst and such a model, data will be read into a remote computer from a time-sharing terminal in the meeting room. It will be shown that changes may be rapidly made and alternative policies investigated ""on line"" to a computer."

Jan 1, 1970

By Michel Dostie

Un séchoir à vis chauffé par induction électromagnétique a été développé et implanté chez Mines Niobec pour le séchage d?un concentré de niobium. Ce séchoir a permis une réduction des émissions de poussières et des gaz à effet de serre de l?usine. Il offre une grande souplesse de contrôle, une meilleure efficacité énergétique et peut être utilisé pour le séchage de granulats, de poudres ou autres substances habituellement traitées dans un four rotatif ou à l?aide de vis chauffées par un caloporteur. Le principe de fonctionnement du séchoir est simple. Trois inducteurs opérant à la fréquence du réseau électrique assurent le chauffage des parties métalliques du séchoir, dont des vis qui servent à convoyer le matériel. Le contact du matériel avec les parties métalliques chaudes permet le transfert de l?énergie requise pour le séchage. La conception de ce type de séchoir requiert un équilibre adéquat entre les besoins associés au chauffage par induction et ceux liés au transfert de chaleur par contact et au transport du matériel dans le séchoir. Cette première implantation industrielle a nécessité des efforts de développements importants et une collaboration des différents intervenants. Une revue des principes de conception, des difficultés rencontrées et des performances obtenues sera présentée.

May 1, 2007

By R. Blazej

Machinery Systems Division (MSD) in the Institute of Mining Engineering at Wroclaw University of Technology specializes in belt conveying systems analyzing, calculating and design. Within the division operates the certified Laboratory of Belt Transportation (LTT) and Laboratory of Rollers. Since few years, a group of several people have begun work on developing a comprehensive system for the automatic evaluation of condition of conveyor belts working in the mines. Group uses both magnetic devices developed by specialized companies servicing belts and its own machine vision system developed for assessment of belts covers and edges during belt movement (up to 7 m / s) on the specially designed for this purpose the test conveyor. Recently they have got the research grant funded by the National Centre for Research and Development (NCBiR) for development of the system for automatic diagnosing of conveyor belts? condition and aiding of rational belt management. On the basis of previously created diagnostic tool called ABCDE (Automatic Belt Condition Diagnostic Equipment) the five modules: vision-A magnetic-B, preventive-C, forecasting?D, and determining safety factor-E will be developed. They will automatically interpret data about conveyor belts? condition to indicate the extent and timing of repairs, to prevent failures and to select the optimum moments for their replacements. The system will use results of ongoing research & development and planned research concerning modeling of belt wear using evolutionary genetic algorithms. The reached stage of research can not yet allow to start the implementation work by potential users. It is therefore necessary to pursuit research in real scale, the development of new modules (C-E) and intensive testing of the system in working condition with system calibration to optimize the economic effects.

Aug 1, 2013

By C. G. Williams

IN preparing this paper on Canadian mine taxation, there has been no attempt to detail the requirements of the various taxing bodies; but rather to consider the matter from the standpoint of its underlying principles and give a general idea of the methods adopted. I have added an Appendix setting forth the principal features of the various Acts, which should be used for general reference only, since new rulings alter minor details from time to time. In current legislation, many important points are left to the discretion of the Ministers and their deputies. We are, indeed, fortunate in having in Canada an able and conscientious body of permanent officials, who bring a sense of justice and courtesy to their work which is most commendable, and which has done much to simplify the working out of general problems. The production of metals may rightly be deemed a form of manufacture, but differs from the average manufacturing business in three important respects: (1) In its early stages, it is wholly speculative, since it is impossible to make any definite appraisal of value or possibilities. (2) The principal asset of any mine, i.e., the ore in the ground, is a wasting asset, and is irreplaceable. (3) Any additional burden by way of taxation cannot be passed on to the public but must be borne entirely by the producer. Having regard to the first of these differences, it is apparent that, since the risk of loss is great, the reward in case of success must be correspondingly great. This fact seems to be constantly overlooked by those who regard the all too few outstanding successes in Canadian mining history as fit prey for predatory legislation. As an illustration of the speculative nature of early mining development, let us consider the Province of Ontario-and I take this illustration simply because I am more familiar with conditions there, and not because I believe it differs greatly from any other province. From 1907 to 1933, 165,243 claims were staked and recorded, from which 43 mines were developed which paid one or more dividends. There was, of course, some duplication through re-staking; also, on some claims very little work was done, and most mines have more than one claim. But, since staking and recording cost real money and effort, each of these claims must have been considered to have had merit.

Jan 1, 1935