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By T. M. Waterland

A GREAT deal of work has been done at Britannia during the past three years in improving and standardizing rounds for development headings, and the results obtained have been very gratifying. The round which has recently been adopted as a standard for all drifts and cross-cuts has, in some instances, doubled the average length of break formerly obtained. It has also increased the footage of advance per labour shift and reduced explosives' consumption. At the present time, with a shortage of skilled labour, more control is necessar7 in directing the drilling of rounds. The use of a standard round has been o great assistance to the foremen and shiftbosses. NATURE OF GROUND Most of the ground encountered consists of a moderately silicified chlorite schist, known locally as G.M.S (green-mottled schist). It cannot be termed hard ground, because a three and one-half inch Leyner will drill at an average rate of twelve inches per minute. Due to the abrasive nature of the ground, the gauge of the steel wears rapidly and in most cases one set of steel is needed for each hole. The ground is not 'free breaking and holes must be spaced correctly to obtain a maximum break. DEVELOPMENT OF STANDARD ROUND FOR THREE-SHIFT OPERATION Late in 1940, a development programme was started involving 7,000 feet of drifting, 6 ft. By 7 1/2 ft. In cross-section, in two headings. Plans were drawn up to advance the headings on three shifts. Equipment used in the headings was as follows: D.A.35 Leyner?machines, Eimco Model 12B mucking machines, nine one-ton end-dump cars, one Mancha Little Trammer on the longest heading, 20-pound rail, 4-in. 15 compressed-air line, 15-in. Fan pipe connected to 5 h. P. Coppus fan. Diamond-drill cross-cuts, 16 feet in length, were cut every 250 feet. Switches were installed at these cross-cuts and they served as passing points for the cars. One siding seventy feet in length was cut in each heading at approximately the half-way point. The cycle of operations planned was to muck out, drill, and blast each shift. Previous performance in this type of ground indicated that a daily advance of 12 feet to 14 feet might be made. However, if a better type of round could be developed, an increased daily advance would be possible. A study of the time available for each operation in a net working shift of six and one-half hours indicated that the maximum depth of round that could be mucked, drilled, and blasted each shift would be six and one-half feet. When this maximum depth was decided upon, the next problem was to develop a satisfactory round. Due to ventilation difficulties and to the short net working shift, the whole round had to be blasted at one time. In other words, no blasting of the cut-holes could be done.

Jan 1, 1942

By K. E. Waters, J. E. Nesset, F. Rosenblum, J. A. Finch

An advanced laboratory-scale weathering apparatus has been developed at McGill University to study the effects of weathering (ambient temperature oxidation) on the self-heating of sulphides. Previous work by the authors has shown that the problematic self-heating of sulphides is inherently linked to the degree of oxidation (weathering) of the minerals: un-oxidized active sulphides exhibit little or no self-heating while the same material when weathered can generate extensive self-heating bringing temperatures well above 100 0C. In this study the effects of environmental conditions (weathering time, ambient temperature, sample moisture, relative humidity, and oxygen content) were evaluated with respect to the self-heating response of a pentlandite-pyrrhotite nickel sulphide concentrate.

Jan 1, 2015

By Boyd Davis, Vladimiros Papangelakis, Douglass Duffy, Michael Carlos

"The processing of lateritic saprolite in hyper-concentrated magnesium chloride brines offers several potential advantages for the hydrometallurgical production of nickel. An aggressive HCl-MgCl2 leach at atmospheric pressure can significantly reduce magnesium dissolution, and offers the ability to recover HCl and MgO by a less energy intensive process than conventional techniques via the formation of magnesium hydroxychlorides. Inevitably, the high chloride concentration renders iron fully soluble during leaching and thus requires subsequent iron control and disposal steps. Experimental measurements coupled with OLITM modeling were conducted to investigate the behaviour of iron in concentrated magnesium chloride brines, in terms of chemistry (nature of iron species) and solubility limits. The solubility of ferric chloride in magnesium chloride solutions of concentrations and temperatures relevant to this process was controlled by a previously unreported solid phase: 2.5FeCl3·MgCl2·7.5H2O. Iron precipitation tests on synthetic leach solutions without seeding indicate a metastable akaganeite precipitate which transitions to hematite upon equilibration. Magnesium chloride solubility in ferric chloride solutions was also investigated to allow the simulation of a ternary phase diagram for the MgCl2-FeCl3-H2O system, in order to determine process conditions that avoid unwanted chloride precipitation.INTRODUCTION In the search for more economical processes to treat lateritic saprolite for nickel production, chloride hydrometallurgy has been increasingly investigated. While High Pressure Acid Leaching (HPAL) can frequently economically treat lateritic limonite, the presence of saprolite negatively affects process economics. The higher magnesium content of saprolite increases acid consumption, because magnesium sulphate, unlike iron and aluminum sulphates, does not hydrolyze in HPAL. This soluble magnesium decreases the sulphuric acid strength by an amount greater than the amount of acid stoichiometrically required to leach magnesium, which must also be disposed of or recovered (Jankovic, Papangelakis, & Lvov, 2009). Due to these issues, pyrometallurgy is most commonly employed to treat lateritic saprolite, via the Rotary Kiln-Electric Furnace (RKEF) process; this process uses a rotary kiln to dry and partially reduce nickel and iron oxides before sending the calcine to an electric furnace for smelting to produce a ferronickel product for the stainless steel market. Although the problems encountered during hydrometallurgical processing are avoided and nickel recoveries are high, high capital and energy costs prevent the application of this process to lower grade lateritic saprolite deposits (De Bakker, 2011)."

Jan 1, 2016

By W. F. Harkness, D. Hodgkinson

"A non-destructive testing program was established at Crows Nest Resources (C.N.R.), Line Creek mining operation following an in-service fatigue failure of a front wheel spindle on a large haulage truck.This failure identified a definite need for improvements in the ultrasonic techniques used during the mandatory spindle integrity examinations. Initial investigations using common mining industry ultrasonic examination techniques showed that the smallest detectable cracks were 75 mm in length for the spindle types in service at the C.N.R. site. The Initial findings indicated that inadequate inspection technique design was the cause of the poor performance. To improve inspection reliability it was identified that improved ultrasonic techniques were required. Results using designed ultrasonic techniques were encouraging, with the detection of simulated and natural cracks 12 mm long achieved. The cost benefits associated with the extended spindle life, following the removal of these small fatigue cracks, far exceeded those of the expertise and effort necessary to implement and conduct the N.D.T. program.Introduction During 50 years of evolution, non-destructive testing (N.D. T.) has progressed from a laboratory curiosity to a well accepted and invaluable tool used in the assessment of material integrity. Unlike destructive testing, N.D.T. does not deform or render the material useless. Non-destructive tests may involve many applications, from the determination of a corrosion prevention coating thickness to the examination of a raw material for internal and external deformities.Within the mining sector, highly-stressed components will normally have been subjected to some form of non-destructive test during their manufacturing cycle. These tests are used to ensure the component does not contain material flaws whichmay be detrimental to its service performance.While the component may have assured quality when produced, deterioration by fatigue may occur during an aggressive service life. Large dynamically-loaded components such as haulage truck front wheel spindles are , in particular, prone to this service related problem."

Jan 1, 1987

By H. L. Gibson, T. N. Setterfield, J. J. Watkins, R. W. Hodder

"Abstract - The McDougall-Despina fault set in the Noranda district of northwestern Quebec defines the eastern margin of the Despina cauldron, nested within the district-scale Noranda cauldron. The faults are stratabound in that they displace stratigraphy of the cauldron fill, but do not off-set the cauldron cover. The faults are occupied by dikes that acted as eruptive centers to volcanic members of the cauldron-filling sequence. Measurable displacement across the McDougall-Despina fault set is greater than 750 m, and coincident with post-cauldron volcanism. Feeder dikes cross-cut each other and are typically depleted in Na2O and CaO, and enriched in MgO, K2O, Fe2O3 and MnO relative to fresh flows. Economic and subeconomic massive sulfide deposits occur adjacent to the McDougall-Despina fault set at different levels over a stratigraphic thickness of 3000 m. These include the Corbet deposit, the subeconomic D-68 Zone deposits, and the subeconomic stringer zones of South Rusty Hill and Bedford Hill. Numerous copper occurrences and abundant hydrothermal alteration occur in and immediately adjacent to the fault set.The McDougall, Despina, and adjacent, parallel, ancillary faults define a synvolcanic fault set which controlled the location of magmatism, hydrothermal alteration and mineral deposition during the early evolution of the Noranda cauldron. Significant sulfide mineral deposition commonly occurred in proximity to the intersection of the McDougall-Despina fault set with northeast-trending synvolcanic faults. Recognition of synvolcanic faults is therefore a major objective of exploration programs for volcanic-associated massive sulfide deposits."

Jan 1, 1995

By G. M. Ritcey, V. M. McNamara

"In the processing of gold ores by the cyanidation route, effluents which are discharged to the tailings areas can contain up to several hundred parts per million of cyanide in complex combination with similar quantities of heavy metals. Complicating this obvious problem of waste control are concentrations of thiosalts and thiocyanates which are roughly equivalent to the amounts of cyanide species. Although most gold mills are located in thinly populated areas, such contaminants can represent a potential environmental problem due to the various limitations exhibited by on-property ponding.The former Extraction Metallurgy Division of CANMET recognized the problem and, in early 1974, invited representatives of the gold mills to Ottawa to discuss the situation. At that meeting members of the Division presented a ""state of the art"" literature survey of cyanide abatement technology for waste solutions, together with preliminary cost estimate data(1). Shortly thereafter, Environment Canada, together with Environment Ontario, decided upon a guideline of 0.1 ppm (0.1 mg/l) total cyanide content as tolerable for an effluent stream which is discharged, in any manner, to the watershed."

Jan 1, 1978

By A. P. Fletcher, K. Croteau

The intent of this paper is to cover some aspects of preventive maintenance methods which have come into wider usage in recent years as a means of increasing operating efficiencies. Particular emphasis is placed on lubrication and related servicing.

Jan 1, 1967

By S. Markstrom

The Boliden AITIK copper mine is located 100 kilometres north of the Arctic Circle in northern Sweden. A pre-feasibility study was conducted in 2005 with the aim of increasing the capacity of the existing processing plant. After analysis, options to upgrade the existing plant were abandoned in favour of building a new processing plant, with higher capacity and therefore greater profitability. A new plant could be designed with greater flexibility to make potential future expansions easier. A feasibility study for a new 36 Mt/y processing plant including fully AG grinding circuits and flotation was completed in 2006. The project was approved by the Boliden board shortly thereafter. Construction started in the beginning of 2007 and was completed during 2009. Commissioning of the new plant was undertaken in the first half of 2010. The grinding circuit consists of two lines with each line consisting of a 22.5 MW AG mill and a 10 MW Pebble mill in closed circuit with a spiral classifier. The nominal production level is 2 200 t/h for each grinding line. This paper presents the start-up and operation of the grinding circuit.

Jan 1, 2012

By T. Ouellet, F. Chiesa, J. Carignan, D. Levasseur

Common practice for the preparation of permanent mold for aluminum casting is to coat the mold with a ceramic suspension to obtain a chemically stable interface with the aluminum melt. This practice serves two purposes: first, it helps the thermal regulation of the mold and second, it prolongs its life. The possibility of increasing the coating durability by applying it by thermal spray is appealing. Plasma spray of zirconium oxide based coatings was performed on H13 tool steel to study the coating’s thermal fatigue resistance. A unique dip test setup was used to characterize the thermal fatigue resistance of the coatings and of bare H13 steel. Observations of the failure mechanism bring an insight on the requirements of the coating to maximize its durability.

Jan 1, 2014

By T. P. Lim, N. K. Davé

"A modified accumulator method was devised to measure surface radon flux from porous media. It consists of a collector hood type of accumulator with a homogenizer pump and a pressure balancer. The latter was used to compensate any pressure changes produced during sample withdrawal and hence eliminate additional radon transport from the media. Errors resulting from radon back diffusion due to decreasing concentration gradient with time across the interface were also eliminated by measuring radon concentrations in the accumulator for two different periods of time and calculating the true radon flux, J(o), from the solution of a time-dependent radon transport equation in the absence of any pressure and temperature gradients.Core samples from the observation site were also withdrawn for laboratory determination of porosity, moisture content, bulk and grain densities, Ra-226 source concentration and the fraction of Rn-222 produced in the void volume. The data were used to calculate the radon diffusion coefficient for the media.Using the present method, the true value of surface radon flux for an abandoned uranium tailings pile was obtained as J(o) = 2020.2 mBq/m2/sec (54.6 pCi/m2/sec) compared to the value J = 1406.0 mBq/m2/sec (38.0 pCi/m2/sec) obtained by the conventional method. The bulk diffusion coefficient of radon for the media was obtained as 1.2 x 10-7 m2/sec.IntroductionRadon-222 (hereafter called radon) released from uranium mill tailings is a continuous source of environment radioactivity in terms of its transport as an airborne gas and its decay products. The particulate daughter products readily attach to aerosols or dust particles and can further be transported by various other environmental pathways. Typical radon release rates from existing tailings piles vary between 740 and 14,800 mBq/m2/sec (20-400 pCilm2/sec), depending on the nature of the tailings material, moisture content, etc. The United States Nuclear Regulatory Commission (NRC) is proposing radon release rates of 74 mBq/m2/sec (2 pCi/m2/sec) above that of background."

Jan 1, 1982

By P. Moreno

ABSTRACT: The Maras salt terraces, located between Cuzco and Urubamba in the Andes (southern Peru), are living examples of traditional Incan salt production, where present-day artisanal miners produce salt from shallow pans by solar evaporation. In these terraces, natural spring water, eight to nine times saltier than seawater, is used to produce the salt. The field observations and chemical analyses show that the poorly crystalline traditional salt is finer in particle size and contains impurities such as dolomite and gypsum. These differences are the result of shallow pond depth, contamination from wall erosion, and the nonsequential mode of salt crystallization.

Jan 1, 2011

By J. G. Trowell, D. T. Magee

"IntroductionMANITOBA'S first recoverable oil was from the California Standard Daly 15-18 well in Lsd. 15, Sec. 18, Twp. 10, Range 27, W.P.M., completed early in 1951. This well also gave the first indications of commercial production in the Williston basin, which is centred in North Dakota and extends into southeastern Saskatchewan and southwestern Manitoba. Subsequent drilling in the Manitoba portion of the basin has revealed the presence of oil in more or less commercial quantities at various points in an area approximately four townships in width and eleven townships in length.Although completions are becoming fairlly widespread in the area,, the greatest activity is in the Virden district, with the focal point in the Daly field, approximately eight miles west •of Virden. This paper will deal with the various techniques used in the Daly field, where •completion problems have •been unusually troublesome. Techniques evolved there have already been used with success at other points in southwestern Manitoba.Daly FieldGeneralTo date, all production has been from the Mississippian limestone, which is encountered •at depths ranging from 2,300 to 2,500 feet. Pay thickness is •of the order of 100 feet. Core analyses indicate average porosity .of about 9 per cent but permeabilities, for the most part, are extremely low."

Jan 1, 1953

By W. G. Jewitt

THE Box mine, situated in Saskatchewan on the north shore of lake Athabasca, is unique in two respects. It is the first and, so far, the only gold mine in Saskatchewan, and it is the only gold mine in Canada to employ a large-scale forced caving system as the main mining method. Discovered in 1934 by Tom Box, an Edmonton prospector, its subsequent history, while breaking no records for speed, has been one of steady and more or less normal development. Camp and plant are situated close to the shore of Beaverlodge bay, sorne 50 miles east of the Saskatchewan-Alberta boundary and 35 miles south of the north boundary of the Province. The railhead at Waterways, Alberta, is about 220 miles to the southwest. Prince Albert lies some 450 miles to the south. The surrounding country presents a rather rugged variation of the usual Precambrian topography, with hills rising five to six hundred feet above lake Athabasca. The numerous lakes and islands, together with the wide expanse of lake Athabasca, compose an attractive scene, at least in the not over-long 'open water' season. The winters are long but not extremely cold, judged by prairie standards. The small lakes break-up around May 20th and the 'freeze-up' stops navigation early in October. Though apparently remote, the Box mine is fortunate in having reason-ably cheap transportation from Edmonton. The 300-mile railway from Edmonton to Waterways is the most expensive section, the rate for 1st class freight being $1.70 per hundred pounds and for 5th class freight $0.77 per hundred. Freight from Waterways to the mine, approximately 140 miles down the Athabasca river and 90 miles along lake Athabasca, is delivered by barges and tugs for 50 cents per hundred pounds. All freight is delivered during the 'open water' shipping season, which lasts from about .Tune 7th to October 7th. In normal years, barges are loaded to 3 to 3 1/2feet draught up to September 1st. After that date, and earlier in dry years, shallow water at Waterways reduces the barge loads. Barges of 100 to 200 tons capacity handle all mining freight, including pieces up to 15 tons in weight, without undue difficulty.

Jan 1, 1940

By X. -G. Chen, A. M. Nabawy

A novel manufacturing technique for Al-TiB2 nanocomposites has been developed, in which TiB2 nanoparticles were incorporated into liquid aluminum under mechanical stirring and in the presence of a K2ZrF6 flux-wetting agent. The microstructure of the Al-TiB2 nanocomposites was studied using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The microhardness test was conducted to investigate the strengthening effect of TiB2 on the aluminum matrix. The TiB2 nanoparticles were successfully incorporated and dispersed into the aluminum melt in the presence of the K2ZrF6 flux during mechanical stirring. In the as-cast microstructure, most nanoparticles segregated in the interdendritic regions as a result of particle redistribution during solidification. The addition of 2, 5 and 10 wt% TiB2 nanoparticles increased the composite hardness by 60, 90 and 150% respectively when compared to commercial purity aluminum, indicating that the TiB2 nanoparticles imposed a significant strengthening effect on the aluminum matrix. The role of K2ZrF6 flux agent on the incorporation of nanoparticles into aluminum melt was discussed.

Jan 1, 2014

By A. Pawelczyk, D. Hreniak, E. Zych, W. Strek, K. Grabas, A. Ostrowski

"Nowadays recycling became an important rare earth elements (REE) source, which allows to reduce their demand for extraction from natural deposits. At present, the used fluorescent lamps and old type TV or computer monitors kinescopes are selectively collected and undergo processing in the system of recycling. It has been estimated, that utilization of such waste would be sufficient to cover the REE demand for the next 5-8 years. In the developed process, the luminophores were separated from the electronic and electronic waste materials, and processed by hydrometallurgical methods to obtain concentrated REE in form of oxides. INTRODUCTIONInternational Union of Pure and Applied Chemistry (IUPAC) defines the rare earths as a set of seventeen chemical elements, specifically the fifteen lanthanides plus scandium and yttrium. They are considered the most important indicators of the developed technologies and techniques. Rare earths are used, amongst others, for the production of magnetic and superconducting materials, ceramics, lighting, catalytic converters, advanced electronics and alloys. The demand for RE continually increases, similarly to many other primary raw materials. Globalization, the growing demand for limited resources of raw materials, the policy of the countries controlling the raw material market and the economic crisis became a spur for new programs of socio-economic development of the European Union (EU), with particular regard to EU safety for commodities in intermediary as well as long-term horizons (COM 2008), COM 2011).EU countries import most of metallic and chemical raw materials important for their economy. In 2008 a detailed program named Raw Material Initiative was announced. The increase in demand for most raw materials having special importance for the development of technology, and access to of raw materials security of supply affect the future economies of the UE member states and other developed countries."

Jan 1, 2012

By H. N. Tran, D. Barham

"A systematic survey of the appropriate literature in terms of phase equilibria and possible reactions involving deposits in Municipal Solid Waste (MSW) incinerators are analyzed particularly with respect to the theoretical first melting points of typical ashes and the possible presence of a liquid phase at the temperature of ash-metal interface. Conclusions are drawn on the basis of the possible presence or absence of various metal chlorides and sulphates in such situations, and their effects on the problems of fouling and metal corrosion. From preliminary results, it would appear that ZnCl2 is unlikely to be present in any molten phase which causes corrosion because it evaporates rapidly from such liquids. It would also appear that PbCl2 and, by inference, ZnCl2 will sulphate at relatively low temperatures if the flue gas contains SO2 and O2.IntroductionMunicipal Solid Waste (MSW) incinerators produce fly ash which deposits on heat transfer surfaces throughout the furnace, leading to corrosion and loss of energy recovery efficiency. Despite a massive amount of research carried out on the subject of corrosion in MSW incinerators, the problem of corrosion of heat transfer metal is still with us, and no definite over-all cause and effect relationship has yet been identified. In order to make a contribution to the eventual solution of this problem, the authors have examined the problem from the beginning, using their knowledge of fouling and corrosion problems in black liquor recovery boilers as a starting point.The incineration of MSW has been used for many years to reduce the volume of material sent to landfill (ash volume compared to raw waste volume), and, in most cases, to recover energy at the same time by raising steam The steam may be ""low- or high pressure/ temperature"" depending on its end use. The higher the steam pressure and temperature, the greater seem to be the problems with corrosion of heat exchanger metal, presumably because the metal must withstand higher surface temperatures.The chemical and physical composition of MSW is extremely variable, not only on a regional basis, seasonal basis, and day-today basis, but also on a minute-by-minute basis, due to the inhomogeneity of MSW. This makes it extremely difficult to define cause and effect relationships, because both cause and effect are transient in nature."

Jan 1, 1991

By J. N. Hilton, D. Moffett, E. Barnes

"A recent pilot-plant program carried out at Rio Algom's Quirke uranium mine at Elliot Lake, Ontario is described. The goal of the research was the production of tailings basin effluents which were low in total radium-226. The process tested involved precipitation of radium with barium chloride and sedimentation in plastic-lined settling ponds. Adjustment of the tailings basin overflow from its normal value of pH 9.5 by addition of sulphuric acid to about pH 7.5 was found to give approximately a five-fold improvement in total radium-226 removal. A five-month demonstration test resulted in an effluent with a mean total radium-226 activity of44 pCi/L after 2.5 days settling time and 29 pCi/L after 5 days. The results from the demonstration program are used to propose a schedule of achievable total radium-226 activities where precipitation and sedimentation are employed. The maximum suggested values for 5 days nominal settling time are: 30 pCi/L in an annual mean, 45 pCi/L in a monthly mean. 60pCiIL in a weekly mean and 80 pCi/L in any single grab sample.IntroductionRadium-226 has been removed from effluents at the Elliot Lake uranium mines since the introduction of the first barium chloride treatment system in 1965. Current practice, which has changed little over the years, consists of radium-barium sulphate precipitation by the addition of a low do se of barium chloride to the clear overflow from the tailings basin(l·2l. Provision is made for the precipitate to settle in large natural or constructed ponds and lagoons. The residence time in these ponds, which depends on the site, ranges from 3 to 35 days, with varying degrees of efficiency being achieved."

Jan 1, 1981

By William A. Napier

The Mantaro Phosphate Property is located ~ 250 km east of Lima, Peru in the Andean altiplano near the city of Huancayo, Junin District. The Mantaro deposit is a mineralized zone of phosphatic rock currently defined by surface outcrops, trenches and drilling extending over a strike length of more than 30 km and a width of more than 5 km covering ~27,700 hectares. Mineralization is exposed as three roughly parallel exposures (?mantos?) trending in a northwest-southeast direction along the Mancaspico syncline. Estimated mineral resources1 contained in Manto 1 of the Property (4% P2O5 cut-off) as of February 21, 2010, are: Measured 5.548 million tonnes @ 10.8% P2O5 Indicated 33.975 million tonnes @ 9.9% P2O5 Measured + Indicated 39.523 million tonnes @ 10.0 % P2O5 Inferred² 376.265 million tonnes @ 9.0% P2O5 1Tonnes rounded to the nearest 1,000 and grade to 1 decimal place. 2Inferred material reported with no cut-off and an assumed grade. There is considerable potential to expand the resource base. Mantos 2 and 3 of the deposit have been geologically mapped and exhibit surface mineralization widths similar to Manto 1. Given that the deposit is of marine sedimentary origin, it is reasonable to infer that comparable grades and depth of mineralization are present within Mantos 2 and 3. Based on this assumption, the potential mineral deposits within Mantos 2 and 3 are estimated to be approximately: Manto 2 425-435 million tonnes @ 9% P2O5 Manto 3 280-290 million tonnes @ 9 % P2O5 These potential quantities and grade are conceptual in nature, there has been insufficient exploration to define a mineral resource and it is uncertain if further exploration will result in these targets being delineated as a mineral resource. However, should such conceptual resources be confirmed by trenching and drilling, the Mantaro Phosphate Property would rank as one of the most significant phosphate deposits in the world.

May 1, 2011

By R. W. Thompkins

"PREFACEPart 1 of this paper, published in the September issue, covered the occurrence of uranium, radiation from uranium ores, the uranium series, radioactive theory, radioactive equilibrium and application to the radon series, the working level, the theory of emanation and diffusion, transport by thermal diffusion of radon emanating from porous rocks, and definitions.This Part 2, which follows, deals with radiation theory applied to uranium ores, other radon migration factors, factors affecting the radon gas release rate, the measurement of radon gas emanation rates, the tunnel concept, variation of emanation rate with grade and estimating radioactivity from grade analysis.The series will conclude with Part 3, in the November issue, which will discuss the techniques for controlling radiation and provide some example calculations.10.0. Radiation Theory Applied to Uranium Ores10.0.1. The processes of diffusion transport of radon gas, through rock from the fundamental physics is a function o f the radon gas concentration in the interstitial pore spaces and the distance from the surface. Expressed by Fick's first law of diffusion, it is expressed: [ ]10.0.2. The maximum concentration is a function of the emanating power (ß), thus the above equation may be expressed: [ ]10.1. The Effect of Porosity10.1.1. If a constant emanating power is assumed (ß), a family of curves can be obtained for concentrations at varying distances and rock porosities. The curves as originally plotted assumed a constant emanating power of 5 x 10-4 pico curies/litre/sec and show the maximum expected concentrations in the pores in pico curies per litre. Because these concentrations are proportioned to the emanating power, this set of curves can be structured to show the fraction of maximum concentrations possible at various porosities of the rock.10.1.2. Notice that at 10, 20 and 30% porosities a 5-cm sample (hand-sized and drill-sized pieces) has no practical increase in pore concentration. Thus, by measuring the emanating power of hand-sized pieces of ore, the actual radon gas production into any pile of broken ore could be estimated readily."

Jan 1, 1982

By C. Fleming, J. R. Goode

ABSTRACT: Data were produced from two uranium project studies that were conducted in 2008, both involving uranium recovery from leached slurry by resin-in-pulp (RIP) with strong base resins. In both studies, excellent metallurgical results were produced. The loaded resins were eluted with strong sulphuric acid and recycled through RIP circuits in an integrated process. Resin losses by either abrasion or mechanical breakage were immeasurably low. Metallurgical results from these two campaigns are presented, along with a case study economic analysis of RIP versus the alternative processes of counter-current-decantation or filtration and solvent extraction.

Jan 1, 2011