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By B. Lustman

IT has been known for a number of years that the addition of certain alkaline-earth and rare-earth metals to nickel-chromium base electric resistance alloys causes marked increase in their oxidation resistance as measured in an intermittent oxidation test similar to the ASTM—B 76-39 test. However, the mechanism whereby such additions confer protection is still unknown. On the basis of the experimental observation that the increase in life in intermittent tests of nickel-base alloys is proportional to the atomic radius of the added element, Hessen-bruchl has proposed that the added metal ions occupy holes in the oxide lattice which prevent diffusion of nickel ions in the oxide. Horn2 has postulated that the effect of such additions is to accelerate the rate of diffusion of chromium atoms in the metal and thus to favor the formation of Cr2O3 scales. Hickman and Gulbransen3 concluded from electron diffraction observation that the addition of the elements in question results in the formation of a barrier to the diffusion of nickel ions to the surface. In connection with some experiments conducted to develop a test for the resistance to oxidation of alloys in massive form under conditions of intermittent heating and cooling, some features of the oxidation of nickel-chromium base alloys were revealed which may serve to elucidate the mechanism of protection conferred by rare-earth and alkaline-earth elements. Specimens of cylindrical shape 0.360 in. diam x 0.37 in. long were placed in alumina thimbles and inserted into and withdrawn from a Globar-heated furnace operating at 2150°F at 7.5-min intervals. The weight of oxygen absorbed as well as the weight of oxide spalled were measured at intervals. With the particular experimental conditions used, the specimens in a 7.5-min cycle were at temperature for 2 min which corresponds to the heating time of the ASTM test. The weight changes of similar specimens under conditions of continuous heating in air at 2150°F were also measured. The specimens after oxidation were examined metal- lographically and samples of the spalled oxide collected for X-ray diffraction identification of the phases. The specimens used were from the same lot of material used by Hickman and Gulbransen3 and had the compositions shown in table 1. Included in table I are results of ASTM life tests on the materials in the form of wires. These materials, their composition and the ASTM life test data thereon were all supplied by F. E. Bash of the Driver-Harris Co. It may be noted that alloy 13246 of 80 pct nickel, 20 pct chromium nominal composition showed the shortest life in the ASTM test; alloy 12246 with the addition of small amounts of the elements zirconium, calcium, and aluminum, intermediate life; and alloy 12046 with the further addition of silicon, the longest life. In fig. 1 are shown the results of intermittent oxidation tests made on bulk specimens at 2150°F as well as continuous tests conducted at the same temperature. Duplicate tests were made on each specimen. The ordinate scale, inches of metal oxidized, was derived from the experimentally observed weight gain of oxygen by assuming the scale to be entirely Cr2O3. It may be noted that the metal-loss curves during intermittent oxidation show a constant or continuously increasing rate of weight

Jan 1, 1951

The simple act of taking a sample implies that someone will use the information contained in the analytical result to make a decision about a course of action. In the mining industry, the decisions may involve huge capital commitments for opening or closing a mine, or marginal tactical costs that involve deciding if a truckload of mineralized rock should be sent to the mill for processing, or the waste dump. Sampling is among the most fundamental activities in a mining operation, and this paper aims to examine some of the technical issues that can assist in ensuring that samples are representative and correct. Insights into the scale of variability require that we disaggregate sampling variance into its component parts and evaluate each one individually. The work of Pierre Gy in understanding the different sampling errors is the first step in establishing an optimal protocol. This must be followed by the appropriate measures to ensure the protocol is implemented such that minimal bias is introduced in the sampling process. Even with these insights the possibility exists for large unseen and hidden costs can accumulate in a mineral development because of sampling errors. These hidden costs arise due to misunderstanding of the principle factors that affect the size of sampling errors, such as the mass of the sample, the effects of splitting a sample to reduce the mass, and the influence of the nominal particle size. The handling of sample material without due regard to the sampling characteristics of the material being sampled is also a major source of sampling errors. The most significant problem is due to the influence of the so-called volume-variance effect. This effect is a consequence of the support effect and the information effect both of which relate to the difference in size at which samples are collected and mining blocks are extracted. The information effect is a function of the availability of data at the time that decisions are made about the destinations of mineralized rock, namely the mill or the waste dump. Implementation of appropriate sampling protocols in the mineral value chain remains a challenge throughout the industry. The growing understanding and deepening appreciation of sampling theory and methods means we stand on the threshold of a new era for implementing and understanding appropriate sampling procedures and protocols. In the interests of optimal development of the national patrimony it is suggested that standardization through the identification of structural problems and continuous improvement of mining processes be instituted at a national level.

Jan 1, 2007

By E. G. Loesche

Grinding mills in which the comminution takes place between rollers and the surface of a disc, table or ring are generally known as roller type mills. The Loesche Mill, also known as the Disc Roll Mill, is a special type of roller mill in which the grinding surfaces consist of two rollers assembled over a horizontal disc or table which rotates at a relatively low speed. This design is particularly applicable to industry's present day demand for large capacity grinding mills.

Jan 1, 1964

By Stump NW

Until a year ago all isotope on-stream analysis utilised flow cells similar to those designed for conventional X-ray on-stream analysis. These systems incorporated a fairly complex sampling system necessary to present a representa- tive air-free sample of the main process to the flow cell. Maintenance costs and capital costs associated with flow cells and sampling systems have been generally high. Costs can be greatly reduced and reliability greatly increased, by using isotopes incorporated in immersible on-stream analysis probes which actually dip into the main process stream eliminating the need for sampling. A bonus of other advantages associated with immersible probes includes temperature stability and ease of calibration. This paper discusses details and results of the probe systems, justifica- tion for installing on-stream analysis, comparison of conventional X-ray and isotope techniques, and a brief survey of methods of analysis using radio- isotopes in on-stream elemental determinations.

Jan 1, 1971

By A. D. Garman

This paper presents one of a series of digests of foreign mining legislation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries . This interpretation of the laws of Haiti has been prepared from the best available information in Washington, but is released subject to correction and amplification , if necessary , by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State .

Sep 1, 1930

By McKenzie P

The techniques of geological control developed by the Coal Geology Sections of the Broken Hill Proprietary Company Limited and Australian Iron and Steel Proprietary Limited in providing geological service in the coilieries operated by these associated companies cover the provision of geological control for both planning and production in each of which the significance of geology has in the past been only poorly appreciated by the coal mining industry.While the adoption of similar techniques is well within the capacity of major companies there is considerable scope for the development of government geological services providing specialized assistance of this nature for smaller scale producers.INTRODUCTIONThe coal mining industry in Australia can instance many notable mistakes caused by failure to obtain sufficient geological information or by incorrect interpretation of available geological evidence both before the commencement of mining and during the progress of operations. Substantial development undertaken in, areas with insufficient or inferior coal reserves, difficult mining conditions caused by failure to adjust operations to geological circumstances, and the irregular development of mine workings caused by unexpected geological features, all bear witness to the lack of geological foresight by the industry.Along with the more widespread general use of applied geology, an increasing acceptance has developed during the past ten years of the valuable contribution which can be made by this science to the exploitation of coalfields. In spite of the advances which have been made, there is still a wide scope for further detailed application of geology throughout the coal mining industry in Australia.

Jan 1, 1963

By J. P. Wiser

THIS paper discusses testing and quality control of milled asbestos fibre. It has been composed with the intention of: (I) Summarizing past, present and probable future methods of testing and classifying the various grades of commercial asbestos produced by the Quebec asbestos industry. (2) Acquainting those unfamiliar with the methods used for evaluating, testing and controlling the grading and the quality of Quebec chrysotile asbestos fibres with some of the physical and chemical procedures currently used for that purpose. (3) Discussing some of the complications facing the producers, such as variations in the orebody and special requirements of asbestos manufacturers. ( 4) Detailing some of the present quality control methods. SUMMARY OF PAST, PRESENT AND PROBABLE FUTURE TESTING METHODS Past During the first years of production of commercial asbestos in the Province of Quebec, fibre testing and quality control were based principally on dry screen analysis and visual inspection. These methods were gradually expanded during the period from 18, 90 to 1932. In 1932, standardization

Jan 1, 1962

By Leiting Yue, Peng Ren, Yu Shen, Zhihong Liu, Haibao Shao, Longgong Xia, Feng Yu

The Kennecott-Outotec Flash Converting technology has been proven as an advanced and mature process in 5 individual plants during the past 2 decades. High grade copper matte (65–72%) produced in the flash smelting, or other smelting technologies is granulated to 3-5mm granules in a water torrent, and further crushed to fine powder (≈50µm) and dried to contain less than 0.3% H2O. Oxygen enriched air, together with fine copper matte powder and lime flux are injected into the reaction shaft by a matte burner. The copper making and slag making reactions will happen in very short time and distance during the particle falling and settling. However, industrial practice has found negative effects caused by sodium contamination. Na is introduced in the copper matte granulating process, and appears as Na2SO4 on particle surface. When Na content was high, scaling problems in the boiler will be worse, and the processing air will be blocked by the growing accretion around the matte burner, and as-produced blister copper is always high in S and O. In this present study, an industrial matte sample was used in the experimental work. Na was introduced into the matte powder by Na2SO4 solution soaking. The burning behaviour of the doped copper matte powder has been investigated as a function of the impurity concentration and processing temperature. Morphology and composition of these samples explained how Na2SO4 converts and reacts in the oxidizing atmosphere, and how they or their converting species influence the burning behaviour of matte particles. Cross-sections of as-prepared samples were analyzed with SEM-EDS, and the reaction mechanism has been carefully interpreted. Results from the present study can benefit both academic and industrial people. INTRODUCTION "Flash Converting" technology was developed jointly by Kennecott Utah Copper Smelter and Outotec (Finland) OY in 1992. The first industrialization of the technology was in Utah Smelter in 1995. Since 2006, it has been successfully applied in Xiangguang Copper, Tongling Jinguan Copper Branch, Fangchengang Jinchuan Copper, and Ningde Southeast Copper. The technology has also been further developed in those smelters. At present, roughly 2 million tons blister copper is produced annually through the Kennecott-Outotec Flash Converting technology, accounting for more than 10% of global primary copper production. The technology has advantages of high efficiency, high sulfur capture rate, good in environmental issues, mature equipment supporting, high automatic control level, low comprehensive energy consumption and flexible connection with the smelting unit, which make the technology to be one of the best choices in investing a new large-scale copper smelter or updating an old copper project in the world.

Jan 1, 2019

By Eugene Jak

Copper sulphide processing technologies face increasing pressures associated with decreasing concentrate grade leading to increasing thermal inefficiency and lower productivity. Impurity concentrations are on average increasing, creating potential environmental risk and additional treatment costs. In copper flash smelters dust, partially oxidised materials and fume formed from the condensation of volatile impurities, are routinely recycled to the feed. In the converting stage the heat balance is maintained by charging anode reverts and other inert materials. In both cases, the thermal energy available from sulphide oxidation is not fully utilised or optimised. The productivities of both smelter and converter stages can be potentially increased through the addition of a high copper, low iron, low impurity precipitated copper product. Calculations are carried out for fayalite smelter and calcium ferrite converter slags using an optimised FactSage thermodynamic database. The potential for significant increases in smelter and converter productivities using existing technologies are predicted.

(Members, are urged -to send in for this column any notes of interest concerning themselves or their fellow-members,). Members and guests R: ho called at Institute headquarters during the period Dec: 10, 1916 to Jan. 10, 1917: F. L. Antisell, Perth Amboy, N. J. William Kelly, Vulcan, Mich. F. J Brulé, Toronto, Ont., Canada. W. H. Lanagan, San Francisco, Cal. Zar T. Crittenden, The. Pas, Mau, Canada. S. Lefevre, Forest Glen, N Y Thomas F. Donnelly, Tucson, Ariz. ' D. A. Lyle, St..David's, Pa. - John Davenport, Brighton, 14 lass. -Domingo Nugués, Buenos Aires, Argon-. E. E. Ellis, Birmingham, Ala. tine. N. H. Emmons, 3d, Copperhill, Tenn. - H. L. Scaife, Clinton, S. C. W.. E. Erdofy, New York, N. Y. Mortimer A. Sears, Washington, D. C. C. L. French, New York, N. Y. E. Spurny, New York, N. Y.' , M. H. Gannon, Butte,. Mont. R. K. Stockwell, Santiago, Chile. R. E. Hoffman, Hannibal, Mo. Benjamin F. Tibby, Salt Lake City, Utah. C. Vey Holman, Rockland, Me. Arthur P. Watt, St. Francois, Mo. Arthur P. Allen has left the employ of the Calumet &- Hecla Mine and is now with the Highland Min. Co., Ashcroft, B. C., Canada. H: C. Bellinger has been appointed. general manager of the Chuqui- - c mata mine-of the Chile Exploration Co. -

Jan 2, 1917

By A. W. Fahrenwald

Many factors enter into the efficient operation of the reciprocating type of gravity concentrator. Earlier investigators who studied these factor invariably used natural (crushed ore) products for their experiments, but in the present study synthetic products were used. The variables considered were (1) specific gravity of the sand grains, (2) size of sand drains, and (3) shape of sand grains comprising the table feeds. It is recognized, also, that the percentage relationship of the different kinds of grains is a factor affecting results. This factor is variable in one group of experiments but is thereafter kept constant.

Jan 1, 1929

By D. A. Keefe, O&apos

The electrowinning of beryllium from beryllium oxide (BeO) using a molten-salt electrolyte composed of 56 LiF-37 BeF2-7 BeO (mole-percent) was investigated. Anodes made of porous carbon were found to be superior in current-carrying capacity and gave a lower cell voltage than other types of anode material tested. When porous carbon anodes were used) the resultant increase in anode area prevented anode passivation. The cell voltage was 3.3 volts) and electrode current efficiencies of 50 to 70 percent were obtained. The electrodeposited beryllium was recovered as beryllium powder or was coalesced to metal beads by heating to 1,300° C.

Jan 1, 1970

By Gavin Yuill, Kameron Ray

"The impact on vibration model accuracy by input data that is inaccurate was previously unknown, butthought to introduce significant error. This paper explores the impact of accuracy of different GPSreceivers, bulk truck density fluctuations, and charge weight location convention on the accuracy of the final vibration model output. GPS accuracy is compared between a professional Differential GPS, a “prosumer” GPS unit and a standard consumer GPS chip commonly found in cell phones. Bulk truck density fluctuations are compared from the density given by the operator and the actual cup density measured in the field. Charge weight locations explored are from the bottom of the blast hole, center of the powder column, and collar of the hole. The findings show that the weakest link in vibration model creation is actually low seismograph accuracy standards. Errors introduced from such are generally greater than those introduced from other sources."

Jan 1, 2017

Novel flotation reagents were developed to improve the flotation of coarse particles. Laboratory tests conducted on an anthracite coal sample from Kyung-Dong Coal Company, Korea, showed that the reagents can successfully clean 2?3 mm top-size materials. Pilot-scale tests conducted on a 1.41 mm x0 coal gave substantially better results than those obtained using kerosene as collector. The pilot-scale test results were used to develop a flowsheet, in which the 1.41 mm x0 fraction is cleaned by flotation and the 4 x1.41 mm coal is cleaned by single-stage spirals. The performance of this circuit was compared with another flowsheet, in which the 0.5 mm x0coal is floated using the conventional flotation reagent, with the 4 x0.5 mm material being cleaned using two separate spiral circuits. The performance of the two flowsheets was compared by computer simulation. The results showed that the flowsheet consisting of the coarse particle flotation circuit can give substantially higher yield sat a given product grade. Keywords: coal flotation, coarse particle flotation, collector, spirals, computer simulation.

Jan 1, 2002

The April General Meeting of the Institute was held in Kelvin House, Johannesburg, on 15th April, 1970, at 4.30 p.m. Mr J. K. E. Douglas (President) was in the chair. There were also present eight Fellows: Dr J. M. Bereza, H. Britten, R. C. J. Goode, C. E. Mavrocordatos, P. W. J. van Rensburg (Council Members), C. A. Border, D. E. French and S. D. Hill. Four Members, J. A. Boyd, P. Crawshaw, D. P. Hugo and A. H. Munro. Two Associates, including I. Robinson. Eleven Visitors, including A. B. Gould, P. M. Haupt, B. Needleman and A. F. Wentzel. Secretary, D. C. Visser. Total Present, 27. OBITUARIES The President: "It is my sad duty to announce the death of the following: Leslie Richard Ulyate, Fellow, who joined the Institute in 1939 and passed away on 10th March, 1970. Stanley Sterling, Fellow, and Corresponding Member for Canada, who joined the Institute in 1926 and passed away on 25th March, 1970. As a mark of respect to the memory of the deceased and in sympathy with the bereaved I would ask you all to rise and observe a few moments' silence." MINUTES The President: "May we confirm the minutes of the General Meeting, held on 21st January, 1970, as published in the March, 1970, issue of the Journal?" Agreed. MEMBERSHIP The President: "I have much pleasure in announcing that the names of the undermentioned candidates, having been published in accordance with By-Law 5.2.2., Council has elected them to membership of the Institute in the following grades: Associate: Rupert George CaIcott. Students: Clive Martin Davis, William Machiel Eksteen, Cecil John Tainton. From Student to Member: Dirk Johannes Hugo. "I welcome the newly-elected members to the Institute and congratulate the member who has been transferred to a higher grade." TALK AND FILMS The President: "Mr Ballantyne may I call on you to present your talk and films on the 'Continuous casting of steel'?" After the presentation of Mr Ballantyne's programme the President said, "Thank you very much indeed for your talk and films, Mr Ballantyne. This is a fast developing subject and we appreciate having such up-to-date information being made available to us, particularly those of us who are unable to go overseas for this purpose. We trust that you won't let the matter rest here, but will put everything down in a paper which we can publish at a later stage for the benefit of our members. Thank you once again." CONCLUSION The President: "I wish to thank members and visitors for their attendance, and now declare the meeting closed." The meeting closed at 6.10 p.m.

By A Hughes, S G. Rosin

This paper presents the design and construction approach adopted for the widening and stabilisation of the existing decline tunnel forming part of the Scenic Railway Upgrade project at Katoomba in the Blue Mountains of New South Wales (NSW), Australia. The overall upgrade project included new trains and track, rebuilding of the top and bottom station and installation of a new winch and control system. All the works were undertaken over an eight-month period between August 2012 and April 2013 as part of a $30 M upgrade of the railway.The railway is the steepest cable-driven line in the world at a maximum of 52° extending over 350 m and descending from the escarpment into the Jamison Valley. The track was built in the 1880s for coal haulage and is recognised as a remarkable engineering achievement for its time. The tunnel section extends for about 120 m at the start of the decline and is about 3.5 m wide and 3.5 m high. The tunnel was excavated principally within medium to high strength Banks Wall sandstone and given that the widening only involved about 200 mm of trimming of the crown and sidewall this aspect of the work was not a critical support issue, except at the upslope portal. The tunnel crown however is entirely intersected by a major near vertical shear zone which presented significant challenges for the tunnel stabilisation works.Three-dimensional laser survey scanning was used for definition of the tunnel clearance envelope for the widening, and also to subdivide the tunnel into various geotechnical sections to assist in support design. Specifically oriented rock bolts extending beyond the shear zone into stable rock were used together with mesh, shotcrete and extensive strip drains and flushing points for drainage of the shear zone.Unique aspects of this project were included into the specifications and work methods. This included construction of a mobile working platform for tunnel works, the use of dry shotcrete application, difficult access for rock bolting and limiting vibration during the tunnel trimming works due to the risks associated with crown instability. The works also took into consideration particular safety constraints/work exclusion areas to address the risk of detachment of rock which could mobilise downslope to the track area below. This was required because other works were in progress such as micro-piling and bottom platform works which were being undertaken concurrently with the tunnel work.CITATION:Rosin, S G and Hughes, A, 2014. Scenic Railway Tunnel upgrade in the Blue Mountains, New South Wales – an approach to design and construction, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 607–618 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By E. G. King

Low-temperature heat capacity determinations of the minerals goethite and pyrophyllite were made in the temperature range from 510 to 298° K. The entropies at 298.15° K were evaluated as 14.43 ±0.15 cal/deg mole for goethite and 56.6 ±0.5 cal/deg mole for pyrophyllite. The entropies of formation from the constituent oxides are -4.4 ±0.2 cal/deg mole for goethite and -12.3 ±0.6 cal/deg mole for pyrophyllite. The standard free energy of formation of goethite from its oxides is ?G°298.15 = 0.16 ±0.20 kcal/mole.

Jan 1, 1970

By Joe N. Magee

As part of the important program of promoting conservation and efficient utilization of petroleum, Bureau of Mines engineers are making studies of secondary oil-recovery projects throughout the United states and publishing reports setting forth the pertinent facts so that others may profit by the experience gained. This report presents the results of a study by engineers of the Bureau of Mines, stationed at Franklin, Pa., of secondary oil recovery in a part of the Cabin Creek field, Kanawha and Boone Counties, W. Va., where natural gas is injected into the reservoir to stimulate oil production. Most oil produced in the Appalachian region at present is obtained from stripper fields in which almost all natural energy has been dissipated. Secondary-recovery methods are used extensively in many oil-producing areas of New York, Pennsylvania, West Virginia, Ohio, and Kentucky for recovering oil not produced by primary-production methods. The part of the Cabin Creek field reported in this study is shown in figure 1 and has been designated by the operator as project 4. In 1944 the developed area of the entire field was approximately 4,200 acres, and the area of project 4 was about 600 acres. In the developed area of the project the oil reservoir is in the Berea sandstone and occurs at 2,914 to 3,410 feet.

Jan 1, 1952

Reduce respirable dust exposure of workmen operating auger-type continuous mining machines. Approach: An auger miner was fitted with an exhaust system which draws dust laden air through a [scruber] and discharges it behind the line curtain. How It Works: Dusty air is drawn into the space above the coal conveyor and through a scrubber, by two fans mounted side by side above the conveyor. Exhaust from the fans passes through a duct to the side of the auger miner, and into tubing that runs back and into the air return passage formed by the line curtain. See Figure 1. Of the 5,000 cubic feet per minute of air normally entering the working place, 4/5 is drawn out through the dust exhaust system. The system was installed on a Wilcox Mark 20 Miner and tested underground by personnel of the Bureau's Pittsburgh, Pa., Mining and Safety Research Center, under a cost sharing

Jan 1, 1976

By B M. Washington, R R. Lovel, G J. Sparrow, M J. Fisher-White

"Work in CSIRO with several Australian ores has shown that?by heating a high-phosphorus goethitic iron ore and then leaching with caustic or acid, the phosphorus levels in the ore can be lowered to a commercially acceptable value of around 0.08 weight per cent phosphorus (P). With increasing heating temperatures up to 1300¦C, the extent of phosphorus removal increased. This is considered to be associated with mineralogical changes in the iron oxide phases in the ore during the heating.Little phosphorus was removed from four high-phosphorus goethitic iron ores containing 0.12 - 0.16 weight per cent P in leaches with boiling water. However, leaches with sulfuric acid removed ten to 20 weight per cent of the phosphorus and leaching with sodium hydroxide removed even more phosphorus to produce leach products containing between 0.08 and 0.12 weight per cent P from three of the ores.After heating at 300¦C, leaches at a low pulp density of 0.5 weight per cent solids with 1 - 5 M NaOH and 0.1 - 1 M H2SO4 gave leach products with 0.06 - 0.09 weight per cent P. The lixiviant concentration required and extent of phosphorus removal depended on the ore. At a higher pulp density of 25 weight per cent solids, leach residues with between 0.07 - 0.14 weight per cent P were obtained.More phosphorus was removed from ores heated at 900¦C. Leaches at both the low and high pulp densities, with 1 - 5 M NaOH and 0.1 - 1 M H2SO4, gave leach products with 0.05 - 0.09 weight per cent P. However, the lowest phosphorus levels were obtained after heating the ores at 1200 or 1300¦C and leaching with 1 M NaOH or 0.1 M H2SO4. Leach residues with 0.02 - 0.06 weight per cent P were obtained, even from leaches at the higher pulp density of 25 weight per cent solids. Leaching tests on heated samples under heap leaching conditions at ambient temperatures have shown that phosphorus levels can be reduced to similar levels to that achieved in an agitation leach within ten days.CITATION:Fisher-White, M J, Lovel, R R, Sparrow, G J and Washington, B M, 2013. Effect of temperature on removal of phosphorus from Australian Goethitic iron ores, in Proceedings Iron Ore 2013, pp 373-380 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013