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By A. H. Lang

Introduction Tin continues to be as much a strategic metal as it was during the war. This situation is due to the fact that the tin mines in the major producing areas of Malaya and the Netherlands East Indies have not yet reached their pre-war production. Moreover, the world requirements for tin in certain fields, particularly in the food pack industries, are steadily increasing. At present, tin is still under International allocation by the Combined Tin Committee, of which Canada is a member nation. This Committee reviews periodically the availability of refined tin for export from the producing countries and makes allocations of tin to ensure equitable distribution to the consumer countries. In 1947, availability permitted an allocation of only 70 per cent of stated requirements. From 1935 to 1938 the price of tin in New York averaged 49 cents a pound and during the war the price in Canada was controlled under a subsidy programme at levels from 60 to 70 cents per pound. Just recently, this price has been raised to 96 cents. The value of the Canadian production amounts to about half a million dollars annually and the whole of this is obtained as a by-product of the lead-zinc-silver ores of the Sullivan mine in British Columbia. In 1947 Canada's imports of tin were 3,961 long tons valued at over $6,000,000. In addition, tin plate to a value of $8,000,000 was imported from the United States; the tin content of this is estimated to be from 650 to 700 long tons. An increase in domestic production would, therefore, be of great national importance, and the present high price may make the search for and development of tin deposits more attractive than it has been in the past. Although no one can foretell what future prices will be, there is reason to believe that, unless there is a drastic downward revision of production costs, the price will be maintained at present levels for some years. A number of tin occurrences are known in Canada, but none of these have been developed for their tin content alone.

Jan 1, 1948

By D. M. Muir

Many plants produce iron(II)/(III) waste liquors which must be treated by neutralisation and precipitation to remove the iron. Iron can be precipitated as crystalline goethite or jarosite by controlled oxidation at low pH and as magnetite by controlled oxidation at high pH, but only at elevated temperatures (>70°C). This study focuses on the characterisation and settling properties of the iron oxides produced at ambient temperatures using various neutralising agents in order to improve the performance of thickeners. It was found that two-stage addition of caustic to FeC12 solutions produced a fast settling material characterised by Mossbauer spectroscopy and XRD as maghemite and magnetite. However, lime and magnesia additions resulted in more ferrihydrite formation and much lower settling rates because of the enhanced oxidation of Fe(II) by air. Settling rates decreased significantly as the proportion of Fe(III) to Fe(II) in the liquor increased. The mechanism of iron oxide precipitation is discussed together with some reasons for the different behaviour of the neutralising agents.

Jan 1, 2006

By Frédéric Flament

The aim of this paper is to present the development of a data validation software as component of a commercial mass balance package. Data reconciliation through mass balance is basically an optimization problem constrained by the law of mass conservation. As any optimization problem solved with a modern and robust software application, erroneous information or starting point will always lead to a solution, whether it is realistic or not. Moreover, good information wrongly weighted by an incorrect error model will lead to the same bad ending. In an industrial context where competition requires accurate information, data reconciliation without validation can be disastrous and calls for data validation before and after reconciliation. The challenge in automated data validation resides in the development of general theoretical solutions. Until now, none has been presented and only partial solutions are available. The development presented in this paper incorporates some of these partial solutions. The integration of human knowledge into the application paved the way to a more general solution. The combination ?theoretical validation ? human expertise? proved to be flexible and reliable enough to be integrated in a commercial data validation package. Numerous examples though industrial applications are presented. These applications demonstrate the validation of raw measurements, user support in the development of error models and validation of reconciled measurements.

May 1, 2001

By K. J. Heale, G. G. Richards, D. J. Rioux, R. L. Stephens

Slag fuming has remained a key process for the recovery of Zn, Pb, and minor elements in the integrated flow sheet at Teck Cominco's Trail Operations for more than 75 years. Since the start-up of the KIVCETTM process and the #3 slag fuming furnace in 1997, a range of process intensification projects have been completed to improve metals recoveries and throughput based on improved process control, mechanical modifications, and, most recently, the implementation of oxygen enrichment of the blast air. This latter project, initially named 'nitrogen depletion' and now 'nitrogen oxygen performance enhancement' (NOPE), is the primary focus of this paper. NOPE reduces the amount of heat required to heat the inert nitrogen gas, and therefore more of the energy input can be used for reduction. It also frees up boiler capacity because the inert nitrogen gas does not then have to be cooled down. A dynamic METSIMTM model was developed to determine the opportunities to improve the process capacity and heat balance to both assist with justifying the project and to verify the observed furnace behaviour. Several process safety management issues were also addressed and a few key minor mechanical modifications were made to allow the project to proceed to commercial implementation at 25% blast air oxygen enrichment. Short term plant trials have confirmed the model predictions. The first three months of a long term, continuous trial showed a 6% increase in zinc fuming rate from average furnace performance despite the implementation of a KIVCETTM fluxing change to assist with minor element recovery that was expected to negatively impact the zinc fuming rate by 3 to 5%. This encouraging result is also in line with the model predictions.

Jan 1, 2008

By B. Lewis

Paper did not make deadline for printing

Jan 1, 1982

By F. R. Archibald

A STATEMENT on this subject by A. D. Turnbull, presented and discussed at the Annual Business Conference of the Metallurgy Division, C.I.M., held in Ottawa on April 22nd 1957, led to creation of a committee "too see if the Metallurgy Division of the C.I.M. can improve this situation". Without discounting the general problems of education and short-ages in other fields, the committee is primarily concerned with deficiencies related to metallurgy. The committee members are: F. R. Archibald, Chairman, A. D. Turnbull, L. E. Djingheuzian, J. U. Mac-Ewan, and L. M. Pidgeon. Following exchange of views among the committee members a general attitude of approach was established and a background of reference material assembled. It is the purpose of this review to acquaint those interested with the reference material, to offer an appraisal of the situation, and to suggest a programme for action by the Metallurgy Division of the C.I.M. Before proceeding with the ?presentation it is fitting to point out that, notwithstanding some rather important developments in public concern for educational matters, as well as changes in the level of activity in the metallurgical industry, the statement (April 1957) by Mr. Turnbull still stands as a sound article of reference.

Jan 1, 1958

By Trang T. Tran-Valade

With continually increasing energy prices, the mining industry has been on the search for new energy optimization technologies. One area that is garnering great interest is Ventilation-On-Demand (VOD). Prior to selection and implementation of a VOD solution, it is important to fully understand the mine requirements as well as its existing infrastructure and the interaction with other automation in place at the site. With this information, a business case can be generated including a cost versus benefit comparison for various control strategies. To assist in the development of the business case, this paper will identify key areas for consideration and recommendations for an implementation plan.

May 1, 2013

By M. W. Gilmore, J. Ndlovu, T. Sepoloane, Anglo American Platinum, L. R. Nelson, R. N. Varty, L. J. Bryson, B. Peyper, J. P. Hagemann

"As part of Anglo American Platinum’s Rustenburg Base Metals Refinery (RBMR) expansion, a new Nickel Electrowinning Tank House, with a nameplate capacity of 32 400 tons per annum, was constructed. Commissioning of the new electrowinning technology, which involved world first full deposit plating, commenced in 2011.The old nickel electrowinning process at the RBMR used starter sheets which, along with a divided cell configuration, was very labour intensive and exposed operators to high levels of aerosols that contained both nickel and acid. To overcome this problem two key design intents of the new technology are aerosol abatement and minimising labour in the electrowinning cell environment, with a design target to reduce the nickel occupational exposure limit (OEL) to half the legislated limit of 0.1 mg.m-3.Commissioning of the new technologies adopted to achieve mist abatement is described, together with a review of technical and operational challenges relating to the titanium blank edge strips, blank roughness and sandblasting optimisation, blank quality control, electrode spacing, polyconcrete cell dimensional stability and cell top furniture. The impact of these on process performance is presented and the development of fault checking and rectification methods, to maintain high process performance, is explained.INTRODUCTIONThe expansion of Anglo American Platinum’s Rustenburg Base Metals Refinery necessitated the construction of a new Nickel Tank House to achieve two primary objectives, namely increasing the nickel electrowinning capacity from 22 500 tons per annum (tpa) to 32 400 tpa nickel, and a design to reduce the nickel aerosols to 0.05 mg.m-3 as a time weighted average over 8 hours, which is half of the legislated occupational exposure limit (OEL) of 0.1 mg.m-3."

Jan 1, 2016

By I. L. Sills

Introduction So many minerals and mineral products are used in the glass industry that it would require an unduly long paper to deal adequately with all of them. Only those that go to make up the batch for the more common types of glass will be discussed here, and even with these only, the list is a lengthy one. It is true that for the body of the glass comparatively few materials are required-as silica sand, soda-ash, lime, and feldspar. The others are used mainly to colour or decolorize the glass, or to give it some other desired characteristic, such as high lustre, greater physical strength, or opalescence; but, although they may be present in very small quantities, they are just as in-dispensable to the glass industry as are the main constituents of the batch. Sand Sand is essentially quartz, the dioxide of silicon, Si02. Most glass contains from 71J to 75 per cent silica. Sand for use in the glass industry, or 'glass sand', is obtained both from deposits of unconsolidated material, commonly referred to as 'sand', and from solid rock-sandstone, quartz, or quartzite. For the manufacture of glass, the material must possess a high degree of purity, as noted below, so that, although sand is widespread in most parts of the world, and sandstone, quartz, and quartzite are not at all uncommon, it is only in certain places that suitable deposits are found. At the present time, most of the glass sand used in Canada is imported from France, Belgium, and the United States. The French material, from Fontainebleau, near Paris, is known the world over as a very high quality glass sand. That from Belgium is nearly as good and is lower is price.

Jan 1, 1934

By M. F. Goudge

MAGNESIA refractories and magnesium metal are both essential war commodities. The need for magnesium, which had just made its debut as a commercial metal a few years before the outbreak of the present war, is widely known because this new and valuable light metal has already received much publicity. Less widely known but equally important in the war effort are magnesia refractories. They are indispensable to the efficient functioning of the great metallurgical plants producing steel, nickel, copper, and other metals, where, because of their resistance to extreme high temperature and chemical attack, they are used in lining the furnaces, which are operated at a white heat. The demand for refractories in the metallurgical industries rose rapidly upon the outbreak of war, and now, in consequence of the continued great expansion under way in the manufacture of steel, nickel, copper, and other metals, the need for magnesia is greater than ever. Since 1915, part of the Canadian requirements of basic refractories has been supplied from the deposits of magnesitic dolomite in Argenteuil county, Quebec. The products from these deposits are excellent for many uses, but the magnesitic dolomite has too high a content of silica and lime to be used in making a type of magnesia brick required in nickel converters, and in the roofs of reverberatory furnaces used in the copper and steel industries. There is now a large and growing demand in Canada for bricks and shapes for these uses. This demand has always been supplied from the United States. Makers of these products in the United States, in turn, formerly imported most of the necessary high-grade, dead-burned magnesia from Austria and Manchuria. Not only are these sources closed, but refractory chrome ore from the Philippines is no longer available and chrome refractories may have to be in large part replaced by magnesia.

Jan 1, 1942

By Ashu Garg, Anirban Bhattacharya

"Friction stir spot welding of aluminum alloy AA6061-T6 sheets was performed with circular (plunge depths 0.4 and 0.6 mm), square and triangular tool pin (plunge depth 0.4 mm) with constant 0.2 mm shoulder penetration to characterize various zones of weld nugget. It was observed that the depth of the stir zone formed below the tool pin is comparatively similar for different tool pins but wider for circular tool pin. The size of another stir zone formed at the interface of tool pin and a tool shoulder is observed to be larger for triangular and square tool pin due to the higher swept rate. Predicted strain from finite element analysis, calculated strain rate using Zener-Hollomon relationship and experimentally measured grain size distribution indicates severe amount of plastic deformation in-and-around the nugget/spot region. Finer grains in various stir zones were observed than thermo-mechanically and heat affected zones. Grain size (at distribution peaks) in stir zones varied around 2.54 µm to 3.69 µm for different tool pin profiles as compared to base metal grain size of 20 µm. Microhardness results indicate that the welded region is quite softened than base metal and maximum hardness is mostly observed around the thermo-mechanically affected zone.INTRODUCTION Friction stir spot welding (FSSW) is widely used for joining the sheets of materials like aluminum, copper, magnesium, etc. The process begins by plunging a rotating tool (generally having a pin and a shoulder) into the sheets to be welded. Continuous stirring of the tool and downward plunging force generates localized heat due to friction at the tool-sheet interface and plastic deformation of the sheet metal. The material gets softened and the plasticized material adjacent to the tool pin starts flowing due to the action of tool rotation and tool plunge thereby causing intermixing and bonding between the overlapped sheets. The tool stirring also promotes grain refinement in the weld nugget associated with high strain, strain rate and thermal cycle. The formation of new microstructure also affects the mechanical properties and efficiency of FSSW joints. Studies also showed that the tool pin design and tool shoulder feature exerts a noteworthy influence on the material flow and intermixing during the FSSW process (Reilly et al., 2015; Hirasawa et al., 2010). Sarkar et al. (2016) studied the material flow and intermixing during FSSW using tracer material method and reported that the size and width of flow zone increases with tool penetration depth. The influence of tool rotational speed on microstructure and stir zone temperature was investigated during FSSW of dissimilar AA6061-AA5754 alloys (Gerlich et al., 2007). They reported that the average grain size in stir zone of AA6061 weld increases with increase in tool rotational speed. In another work, Gerlich et al. (2008) studied the local melting and tool slippage during FSSW of Al alloys. Tool slippage was investigated by calculating the strain rate using Zener-Hollomon relation. Garg and Bhattacharya (2017a) studied the effect of dwell time, tool pin profiles and tool rotational speed on shear strength, microstructure, temperature and strain distribution during FSSW of AA6061. In another work, Garg and Bhattacharya (2017b) analyzed the effect of different tool pins and pinless tools on the shear strength and microstructure during similar and dissimilar FSSW of AA6061-T6 and pure Cu. Chang et al. (2004) proposed mathematical relationship between the average grain size and Zener-Hollomon parameter during friction stir processing of Mg alloy. Solhjoo (2010) presented a mathematical approach to determine the critical strain as a function of peak strain required for initiation of dynamic recrystallization in austenitic stainless steel. Fratini and Buffa (2005) also proposed the numerical model to determine the grain size during continuous dynamic recrystallization phenomenon."

Jan 1, 2018

By J. Lui

At its Copper Cliff Smelter, bulk nickel and copper concentrate is processed in two Inca flash furnaces and Peirce Smith converters to produce Bessemer matte containing 0.6%Fe. After slow cooling and Matte Separation, Bessemer matte is converted into three main products using magnetic separation and flotation technology: (1) a nickel containing chalcocite concentrate (MK); (2) two types of copper containing nickel sulfide (ME and MR); (3) metallics (MYN). MK is further processed in the Inca top blowing bottom stirring MK Reactor to produce semi-blister copper containing ~4%Ni and ~3±1 %S. The semi-blister copper is then purified in the multi-purpose vessels (MPV) to produce blister copper by reducing Ni, Fe and S content through oxidation. High melting point NiO is formed inside the MPVs. The accumulation of solid NiO and other oxides requires periodic cleaning by adding reductant and furnace matte, a unique process called "washout" at Inca. For many years, the reductant used for the "washout" process has been 15%Si Ferro-silicon. With increasing cost and limited suppliers for 15%FeSi, alternative reductants were pursued. This paper summarizes the development and commercialization of new alternative reductants for MPV "washout".

Jan 1, 2007

By J. J. . BRUMMER

Kimber/ires are intrusive rocks whose main constituenr, olivine, has been altered entirely or almosr enrirely ro serpentine. Texture usually is porphyritic, superimposed upon a brecciared one. Diamonds are found only in kimberlites, and are present in economic quantities only in about I% of all kimberlites known. Two glacial drift diamonds, one near Peterborough and one near Timmins, both in Ontario, have been found in Canada and are believed to have been eroded and rransporred from their original source by glaciers. Many more glacial drift diamonds have been found sourh of rhe Great Lakes in the United States, parricularly in Indiana, Illinois and Wisconsin . There are nine known kimberlire occurrences in Canada. Diamonds have been located in rwo of rhem: on lie Bizard near Monrreal and on Somerset Island in the Northwesr Terrirories. The lie Bizard occurrence comprises three kimberlire diarremes; samples of rhe largest one revealed JO riny diamonds totalling 0.0537 carars. The Somerset Island kimberlites are rhe mosr significant yet discovered in Canada. Ar leasr 19 separare kimberlite occurrences are known on rhe island. Testing by Diapros Canada Lim ired, however, revealed only "a few small diamonds". fr is likely rhar, wirh enough time and funds, additional kimberlires, possibly bearing economic quanriries of diamonds, will be found in Canada.

Jan 1, 1984

By J. W. Sanger

The establishment of a central steam-heating system in Winnipeg and its inauguration in October, 1924, has attracted a considerable amount of attention. Not only does it excite the curiosity of the engineer, but it has stirred financial and civic bodies throughout Canada to such a degree that there is now a much keener general interest in this particular type of public utility than has been shown heretofore. This does not mean that we may expect a mushroom growth of central-heating systems in all our larger Canadian cities in the near future, but it does mean that the pioneer work which Winnipeg is now doing will undoubtedly be used to guide others in their judgment as to the feasibility of similar projects elsewhere. The success of the municipal hydro-electric system in Winnipeg, and the low rates for electricity resulting therefrom, was without a doubt the most important factor influencing the citizens of Winnipeg to venture into this new field. The events which led up to the central steam-heating proposal in Winnipeg are interesting.

Jan 1, 1926

By H. J. McQueen

Pressure welding is a solid state joining technique that depends on bringing the parts into sufficiently close contact that inter-atomic bonds are achieved. Pressing is more effective at elevated temperatures where plastic flow causes the asperities to collapse; improved application conditions are derived from hot-work research to clarify temperature and strain rate dependence of hot strength and ductility. The substructure evolution systematically studied in hot working to determine dynamic recovery or recrystallization is applied to clarifying that developed in welding. The various processes are affected differently by work-piece geometry and final shape requirements. In addition to pre-cleaning of the surfaces, the plastic flow helps disperse the remaining oxide layers as was originally exemplified in blacksmith hot forging of layered sword blades and in bellldie welding of wrought iron tubes. The presentation critically compares the utility for various materials and configurations of simple pressure, ultrasonic application, diffusion, explosive, rotary and linear friction and friction-stir processes. Diffusion bonding (primarily Ti) with light cleaning, low pressure, little distortion in protective furnace atmosphere contrasts strongly with the heavy upsetting in friction welding, or complex alloy mingling and substructure variations in friction stir joints.

Jan 1, 2011

By J. P. Grau, J. Z. Lu

"Thickeners/clarifiers are widely used in coal preparation plants, potash processing and other mineral processing facilities. Thickeners play a very important role in slurry treatment systems to accomplish solid/liquid separation. The demand for larger plants and the increased thickener handling capacities sometime require thickener diameters as large as 200m. The development and use of high capacity thickeners makes it possible to increase the handling capacity of these thickeners by several to more than 10 times compared to conventional thickeners. Hence, for a given slurry rate, selection of a high capacity thickener will significantly reduce the footprint of the thickener. Much higher handling rate, higher concentration of underflow, clearer overflow and lower capital cost are obvious advantages of high capacity thickeners; however, some process requirements and the concerns of operational cost, especially the flocculant cost of a high capacity thickener operation, keep some engineers selecting conventional thickeners and staying away from the high capacity thickeners. Forty years after the first high capacity thickener was developed, there are still arguments in the selection of conventional thickeners or high capacity thickeners in mineral processing. The arguments will continue unless there is a clear picture of capital cost vs. operational cost for each of the thickener types. The purpose of this paper is to analyze these costs and to provide guidelines for selection of thickeners. INTRODUCTIONThickeners/clarifiers are widely used in various slurry treatment systems. For mining and mineral processing, thickeners are an integral part of the solid/liquid separation system. The feed to the thickeners are processing slurries. The fundamental mechanism for the solids/liquid separation is for the solid particles in the slurry to gravity settle inside the thickener tank. The clear water overflows from the top of the thickener tank and is typically reused in the processing circuit, and the concentrated underflow is discharged to different downstream process systems depending on the application of the thickeners. The general requirements for a thickener operation include high density of underflow and clear overflow. Since thickener operation consists of continuous feeding, overflow and discharge of underflow, the solid particles will gravity settle against an upward flow with its velocity dependent on the feed rate and the underflow discharge rate. Higher feed rates to a given thickener produce higher upward velocities. Underflow discharge is typically relatively small compared to the amount of overflow. The upward flow tends to take particles up to the overflow. Only those particles having a settling velocity greater than the upward flow velocity will possibly settle out. Hence, thickener feed rate has to be controlled so that the required overflow water clarity can be achieved."

Jan 1, 2012

By Songgen He, Jianchun Guo

With the development of complex, unconventional and deep reservoirs, it shows that many rocks behave plastically with the influence of clay and confining pressure. Traditional linear elastic hydraulic fracturing initiation models are not good predictors for elastic-plastic reservoirs. With the deformation theory of plasticity, a power hardening constitutive equation was developed in piecewise approximation method. Based on the nonlinear constitutive equation, a model of the stress field around the wellbore was developed considering fracturing fluid penetrating effect and in-situ stress anisotropy. At last, coupled with the maximum tensile strength criterion and Mohr-Coulomb criterion, a new elastic-plastic hydraulic fracturing initiation model was built. The following conclusions were summarized in the paper: (1)The piecewise power hardening constitutive equation based on the deformation theory of plasticity can accurately describe the nonlinearity of elastic-plastic deformation. (2)Whether the rock is yielded or not is determined by in-situ stress, yield stress, Biot coefficient and pore pressure. (3)Plastic yield has little influence on radial stress but significant impact on circumferential stress. The radius of the plastic zone is positively correlated with in-situ stress but negatively correlated with yield stress, power hardening index, pore pressure and Biot coefficient. (4)Initiation modes include tensile failure and shear failure when rock is yielded. (5) For elastic-plastic reservoir, the initiation pressure predicted by linear elastic model is much lower if the rock is yielded.

Jan 1, 2015

By D. G. Almond

Nkomati Nickel Mine in South Africa processes one of the world?s hardest ores in a 375k TPM autogenous grinding circuit. The plant employs an unconventional processing circuit, comprising a primary autogenous mill (AG or FAG) and pebble crushing circuit followed by a secondary hybrid pebble/ball mill and classification cyclone cluster. Advanced Process Control (APC) or Expert Control is now generally accepted as an advantage in most modern high capacity concentrator grinding circuits. This paper reviews the installation of model predictive control at Nkomati and examines the results and benefits of installation in an autogenous mill during plant ramp-up. The paper also demonstrates how predefining process control objectives together with good plant and supplier cooperation can achieve a robust and reliable APC implementation on a very short site program. The results conclusively demonstrate operational and economic benefits during circuit operation with the advanced process control system ON. Production performance and circuit stability were significantly better than during manual control.

Jan 1, 2012

By Frédéric Bélanger, George P. Demopoulos, Pascal Coursol, Thomas Feldmann

"The use of scandium in industrial applications is expected to rise in the coming years, in large part due to the expected adoption of new, clean energy technologies such as solid oxide fuel cells or Sccontaining high strength aluminium alloys. Given that the supply of Sc is currently dominated by only a few countries (Russia and China) other sources for scandium extraction need to be investigated. This paper looks at different options for the recovery of scandium from waste solutions generated during the production of TiO2 pigments via the chloride process route. In particular, a direct solvent extraction (SX) approach and possible options for concentrating scandium before the SX step were investigated. It was found that the presence of Ti during solvent extraction causes severe formation of stable emulsions, which can complicate the successful application. This was particularly a problem after multiple contacts of the organic phase with fresh aqueous phase. On the other hand it was noticed that the presence of certain elements in the solution, e.g., iron, could possibly be utilized to concentrate scandium in a solid precipitate.INTRODUCTIONMany newly developed high-tech products depend on the use of chemical elements that are only produced in very small quantities. This can result in high and fluctuating prices, as can be seen from Figure 1, which may cause substitution with inferior alternatives, if possible at all (Reck & Rotter, 2012; US Dept. of Defense, 2013; Whittaker, 2011). One example is scandium (Sc) a member of the extended rare earth element family. There are only a few scandium ore deposits, but most Sc is produced from the processing of by-products of other metallurgical processes (Melcher & Wilken, 2013). Increasing demand for scandium metal and oxide (Sc2O3, scandia) is coming from its increased use in applications such as ceramic lasers (Li, Ikegami, & Mori, 2005; Rainer et al., 1982), high strength aluminium alloys (Lathabai & Lloyd, 2002) as well as solid oxide fuel cells (SOFC) (Thijssen, 2011). Especially, the spread of climate friendly SOFC’s, which are a commercial product today (Bloom Energy, 2014), is expected to be a main driver for future Sc2O3 demand. However, the rate of market penetration of this green technology depends on the availability of high purity Sc2O3 (>99.999%), since it specifically contributes to longer life-time and better safety of the SOFC’s (Bloom Energy, 2014; Irvine, Politova, & Kruth, 2005)."

Jan 1, 2016

By F. W. Gray

A GEOLOGICAL study seeking to determine, for economic purposes, the value of the Sydney coalfield as a source of coal supply. Limitations of the coalfield come under two main heads: (a) Areal extent of the undersea coalfield. (b) The distance from shore at which coal can be mined at a cost of production permitting its profitable sale. Conclusions reached are that the areal extent of seams below the Phalen seam is of. small economic importance, and that non-persistence of these seams in full thickness and quality in the undersea extension of the coalfield will put an end to profitable mining before any limitations connected with distance from the shore-line become operative. With respect to the Phalen seam, non-persistence or deterioration of the seam will become effective in the western part of the coalfield, and less certainly in the eastern part of the coalfield, before operation of limitations by distance from shore. In the central portion of the coalfield, the seam probably persists in commercially workable thickness and quality to beyond the limit of mining set by distance from the shore-line. With respect to the seams above the Phalen seam between the Mountain fault on the extreme western boundary of the coalfield and the assumed termination of the deposition area on the eastern extremity of the field near South Head of Morien, there appear to be only such limitations as arise from engineering approach, distance from shore, sufficiency of strata cover between the sea-floor and the upper coal seams, and quality of the coal (with certain reservations as to the continuity of the upper seams under Sydney harbour and in the Sydney Mines-Little Bras d'Or district). Some of these seams have fragmentary land outcroppings from which their persistence seaward is assumed, and there may be other and still higher seams in the strata column which are entirely submarine.

Jan 1, 1941