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By J. E. Nesset, L. S. Urbanoski, J. R. Goode

"The benefits and advantages of pre-competitive, collaborative industry/university research are not always well appreciated. This paper presents the case study of a current collaborative project between CAMIRO-Metallurgical Processing Division and McGill University that is investigating the understanding and prevention of sphalerite activation in lead and copper-lead flotation circuits. The benefits of the research findings to the sponsors can be maximized by an approach which links the researchers themselves with the sponsors at frequent, interactive project review sessions. Some examples of the findings and their application to industry are also presented along with a general update on CAMIRO-MPD.INTRODUCTIONThe history of Canadian efforts in the area of collaborative pre-competitive research is not long when compared to Australia (AMIRA) and Britain (MIRO). AMIRA (Australian Mineral Industry Research Association) began over 40 years ago and has had a well recognized role in bringing together industrial sponsors and researchers to fund a large variety of very significant development projects in that country, The total AMIRA funding effort for mineral processing work currently exceeds some $Aus 40 million with new projects valued at about $Aus 12 million initiated each year. This high level of commitment by industry has contributed to establishing Australian researchers and their facilities as among the best in the world.Canadian companies have traditionally funded much of their R & D in-house with extensive facilities and large funding commitments. The past 2 decades have seen most of these facilities disappear. The current situation is one in which only the largest integrated metal and mining companies have retained their own R & D groups (e.g. INCO, Falconbridge, Noranda). Industry-funded research at universities was primarily through individual efforts by the mining companies and rarely included collaboration with other mining companies, equipment or chemical suppliers, or engineering firms."

Jan 1, 2001

By Harshad Bhagwat

The objective of this work is to investigate the inadequacies of current CFD based methodologies of model development for predicting combustion behavior of pulverized coal in furnaces. In the present paper, a steady state CFD model was used for in-depth analysis of pulverized coal combustion. The model accounts for turbulence, coal combustion, convective and radiative heat transfer and motion of coal particles. It also uses coal combustion models to account for important processes such as devolatilization, combustion of char and the evolution of fuel nitrogen during coal combustion. The model predicts fluid flow, heat transfer, progress of combustion and pollutant formation (NOx, etc.). The model uses several parameters, which need to be tuned with experimental data, which is not only limited in quantity but also insufficient in detail. Various existing methodologies like part calibration method for tuning of the parameters are discussed. In the present work, the parameters associated with coal combustion models were tuned and validated with published data obtained from an experimental furnace using one such part calibration methodology. The results clearly show that the model predictions differed with the experimental data not only quantitatively but also qualitatively. These discrepancies were attributed to part calibration methodology. A detailed parametric study was carried out to demonstrate the importance of parameters from various classes, namely, combustion kinetics, heat transfer, process and geometry parameters, and CFD model parameters. This investigation clearly indicates that parameters from different classes have significant effect on combustion behavior. The discrepancies in current methodology are discussed and a need for comprehensive methodology is highlighted. Keywords: pulverized coal combustion, computational fluid dynamics (CFD), pollutant formation (NOx), mathematical modeling

Sep 1, 2012

By Farrel W. Lytle

Instrumental analysis has become an indispensable tool in research and production of the rare-earth elements. This development can be attributed mainly to a combination of two factors--the marked chemical similarity of the rare-earth elements, which excludes classical methods of analysis, and the speed and accuracy of instrumental-analysis techniques. With continued improvements in methods of producing high-purity rare-earth elements, keeping pace instrumentally is becoming much more difficult. Accordingly, greater emphasis is being placed on improving instrumental limits of detection and accuracy. The methods employed most frequently for determining impurities in rare-earth elements involve use of the optical-emission spectrograph (3, 4)4/ and the spectrophotometer (9). Although numerous X-ray-emission spectrographic methods (6-8) have been developed for analyzing rare earths, these techniques have not included detection of low-level impurities. This investigation was conducted to find the precision and accuracy of X-ray fluorescence in deter-mining impurities in rare-earth oxides in the 0.01-to 1.0-percent-concentration range.

Jan 1, 1959

By Daniel B. Brimhall

The research presented here was initiated to investigate the role of atmospheric oxygen in the leaching of copper waste dumps. The problem of increasing the recovery rate of copper from these dumps is or great importance considering there are by conservative estimate in excess of fifteen billion pounds of copper located in dumps in the western United States. At this time, there is an increased interest in recovering copper from these dumps on a large scale. Large tonnages of low-grade material are being placed on the waste dumps of most copper mining operations in the western United States each day. The size of these dumps ranges from 5.5 million tons at Mineral Park, Arizona, to 4 billion tons at Kennecott's Utah operation (1). Leach solutions are recycled and contain ferrous and ferric sulfates. Large quantities of dissolved aluminum, magnesium and calcium salts may also be present. To this solution make up water is added to maintain the solution inventory and sulfuric acid is added for pH adjustment. Iron is introduced into the leach solution by the dissolution of the iron-containing sulfide and oxidized minerals present in the ore deposit. In addition to the iron from dump leaching, iron is also introduced during the precipitation process when the pregnant solution is passed over metallic scrap iron if cementation is used to reduce the copper in solution.

Jan 1, 1972

By Tony Szwilski

Indonesia has enormous mineral resources. Its population of more than 180 million people inhabit most of the more than 13,000 islands. The country is becoming a significant economic power in Southeast Asia. Indonesia is the largest Muslim country in the world. Java, its largest island, is the most densely populated area. The country's diversity is its strength. However, as only an estimated 16 million inhabitants speak bahasa Indonesia as the first language, communication problems endure. Although burdened with large debts, Indonesia has been able to service the debts better than most developing nations. This has given it high credibility and, with increasing frequency, creditor nations compete to provide Indonesia loans with the most the most favorable financial terms. Recent rising prices of petroleum crude has further improved Indonesia's economic status. It maintains a policy of stable oil prices that it promotes in OPEC, of which it is an influential member. As a result, Indonesia is becoming increasingly attractive to foreign investors. The South East Consortium for International Development (SECID) is made up of 34 universities in the southeastern US and Indonesian partners Lembaga Afiliasi Penelitian dan Industri (LAPI) of the Institute of Technology in Bandung, West Java. SECID bid successfully against international competition to develop new academic programs and campus for the Sriwijaya University UNSRI) in Palembang, South Sumara. Funding for the project was provided by the government of Indonesia through a loan from the Asian Development Bank (ADB). There are 47 public universities

Jan 1, 1991

By E. M. Cameron

Reconnaissance radiometric and geochemical data have been obtained for an area on the western shore of Wollaston Lake that includes the Rabbit Lake uranium deposit. The study area is extensively drift cover ed. The geochemical data were obtained by analysis of center-lake sediments and surface waters for a variety of elements and other constituents. The airborne radiometric data comprise measurements of eU, eTh and K obtained with a .50,000-cc NaI (Tl) detector at a mean terrain clearance of 120 m and 5-km flight-line spacing. Uranium in lake sediments and uranium in waters are the most effective geochemical indicators of uranium mineralization; the other elements measured are not notably anomalous. A sample site density of one per 1 8 km 2 is more than adequate for identification of the mineralized area. Because many water samples contain close to or below the current analytical detection limit of 0.05 ppb U, the use of sediments is generally favoured. for broad-scale reconnaissance in the region. Uranium in these lake sediments appears to be little influenced by variations in the organic or iron and manganese content. The most effective radiometric indicator of the mineralization is the eU/eTh ratio. This parameter is less influenced by environmental variation on the ground beneath the flight line than eU alone . The eTh/K ratio is anomalous under the Athabasca Formation unconformity where, in places, the uranium mineralization is localized.

Jan 1, 1977

By William W. Elmer

This paper, describing the mining method at the Black Butte quicksilver mine, is one of a series of papers being prepared by the U. S. Bureau of Mines on mining practices, methods, and costs in the various districts of the United States. It is presented to show the mining practice and costs in the successful treatment of low-grade quicksilver deposits. The operation discussed is an excellent example of w1-pat can be done in working a limited tonnage of low-grade ore under sound management. The Black Butte mine is situated at Black Butte, Lane County, in the southern part of the State of Oregon, 17-1/2 miles from Cottage Grove -- a station on the Siskiyou branch of the Southern Pacific Co. The Black Butte mining district lies in the foothills of the Calapooia Mountain Range, which connects with the Cascade Range on the east and with the Coast Range on the west. The elevation at '.lie reduction plant is 1,000 feet above sea level. The apex of Black Butte Mountain, or which the mine is situated, has an elevation of 2,700 feet. The district possesses exceptional natural facilities infrequently met with elsewhere for the mining and reduction of cinnabar ores. Several factors which contribute to the unusually low mining costs are:

Jan 1, 1930

By G. E. Pellissier, P. H. Salmon Cox, B. G. Reisdorf

Banding that occurred in plates rolled from the early production heats of 18Ni(250) maraging steel is described and related to the segvegation of certain alloying elements (nickel, molybdenum, titanium), the extent of which was quantitatively evaluated by means of electron-microprobe analysis. The effect of banding on mechanical properties is discussed, with particular reference to observed directional differences in plane-strain fracture toughness of plates. It is shown that banding originates as interdendritic segvegation during ingot solidification and persists in some degree through normal soaking and hot reduction to plate. The results of the study showed that heating sections of small laboratory-cast ingots at 2200°F for 4 hr was sufficient to markedly reduce microsegregation and to considerably improve mechanical properties. Hot rolling of 7-in.-thick ingot sections to 1/2-in.-thick plate effected a similar reduction of microsegregation, but resulted in even greater increases in ductility and toughness than that obtained by homogenization treatment alone. DURING the past few years, considerable attention has been directed towards the low-carbon, high-alloy maraging steels and in particular towards the 18Ni-8Co-5Mo-0.4Ti alloy. The steels of this group, having an excellent combination of high strength and toughness, have a number of advantages over their more conventional medium-carbon low-alloy, quenched-and-tempered counterparts. In the annealed condition, the maraging steels are in the form of a ductile marten-site; aging at a relatively low temperature, typically 900°F for 3 hr, increases greatly the strength through the precipitation of intermetallic compounds. One problem in the early production heats of maraging steel was that the finished plate frequently displayed a banded structure. Previous work on other steels1-' had established that banding in wrought products is either a direct or an indirect consequence of chemical segregation, which occurs during solidification and persists to some extent through normal thermal and mechanical treatments. For example, Smith and others: in a study of low-alloy steel, were able to correlate the severity of banding in the wrought product with the degree of interdendritic segregation of nickel and chromium in the as-cast ingot. The effect of banding on the mechanical properties of steels is usually considered to be detrimental, although there is only limited evidence to suggest that a marked improvement in properties can be obtained with less heterogeneous structures. Comparison of the longitudinal and transverse tensile properties of banded and of homogenized 4340 steel showed that only the transverse ductility was improved by homogenization, but even then the improvement was not commercially significant.' Conversely, homogenization of through-the-thickness tension specimens of quenched-and-tempered steel plate, containing 1.47 pct Mn, increased the strength by as much as 10 pct and the tensile ductility by at least a factor of twos5 This improvement was related to the elimination of manganese-rich bands, which also are one of the factors responsible for cold cracking in the heat-affected zone of metal-arc welds.7 In the present study the nature and severity of banding in early commercial 18Ni(250) maraging steel plate and in laboratory-melted 18Ni(250) maraging steel plate was determined. The effects of banding on plane-strain fracture toughness and the effects of thermal homogenization treatments on the strength, tensile ductility, and toughness of 18Ni(250) maraging-steel as-cast ingots and rolled plate were evaluated. In addition, the effects of hot deformation by rolling on the mechanical properties of ingots were determined. 1) STUDIES OF BANDING IN EARLY PRODUCTION PLATE The chemical composition of the steel (A) used in this part of the investigation is shown in Table I. Banding was not clearly evident in either as-rolled or annealed* plate, but annealed and agedc** plate had a banded structure. The typical banded condition, Fig. 1, consists of layers of unetched austenite (white) and dark-etching martensite in a light-etching martensitic matrix. X-ray diffraction measurements showed that this steel contained more than 6 pct austenite. An electron-probe X-ray microanalyzer (using a focused beam of electrons) was used to determine the composition of the bands and of the material between the bands with respect to the main alloying elements— nickel, molybdenum, titanium, and cobalt. The recorded X-ray intensities were converted to concentration values with the use of a standard of similar composition. To facilitate probe positioning, all analyses were conducted on specimens that had been given a light etch. The influence of this etching on the analytical results was negligible; analyses made on the identical area before and after etching yielded essentially the same concentration values. The results of the electron-microprobe analyses at selected points revealed that the layers of austenite and adjacent dark-etching martensite contained greater amounts of nickel, molybdenum, and titanium than did the surrounding matrix, Table 11. The austenite layers

Jan 1, 1968

By D. Cronin, A. Plumtree, A. Hosseini

"Crack in corrosion (CIC) linepipe defects are hybrid defects not directly addressed by existing assessment methods. To investigate the collapse pressure of these defects, CIC defects were formed in 508 mm (20 in) diameter, 5.7 mm thick API X52 linepipe. These defects were 200mm long and varied in depth from 3.0 to 3.8 mm. The respective failure pressures decreased from 14.3 MPa for the plain pipe to 7.9 and 6.2 MPa respectively. A standard FAD method was applied to evaluate these defects as equivalent length and depth cracks, predicting the rupture pressure conservatively by 18% on average. However, when assessed as equivalent cracks with a reduced wall thickness corresponding to the corrosion depth, the predicted collapse pressures were more accurate, approximately 14% conservative on average.INTRODUCTIONPipelines are a safe and efficient method for transporting high volumes of oil and gas. However, aging pipelines may experience defects, such as cracks or corrosion. Present approaches include detection, assessment and repair of defects before they may become critical to the integrity of the line. There are different codes and standards for assessing pipeline defects, depending on the type of defect, with API 579 (API, 2000) being the most common code for the assessment of cracks in oil and gas pipelines . Corrosion is commonly assessed using RSTRENG (Kiefner & Vieth, 1989). Other methods such as the Finite Element method and the CPS method (Cronin & Pick, 2002) may be used for crack and corrosion, respectively.At present, there is no specific method or procedure for assessing crack in corrosion (CIC) defects, and as a consequence there is a need to provide an assessment and evaluation of the integrity of these defects in order to determine the requirements for defect repair or hydro line testing. Hence, the goal of this study was to provide guidance for the assessment of CIC defects for linepipe.CRACK IN CORROSION DEFECTS (CIC)Significant amounts of corrosion and cracking are not generally found together (Hosseini, 2010). However, a new hybrid defect including cracking within corrosion (CIC) has been identified in operating pipelines. In this case, cracking coincident with corrosion (schematic shown in Figure 1) provides the motivation for the current study."

Jan 1, 2012

By H. Russell, N. DePriest, J. D. Quaranta

Valley-fill structures built of blasted rock overburden from Appalachian mountaintop surface mines pose many reclamation challenges. The steep mountainous terrain, short valley lengths, and straight stream channel profiles create significant challenges to implementing fluvial geomorphic landform design in terms of both form and function, and from a safety and constructability perspective. The fluvial geomorphic landform design approach balances erosive and resistive forces by considering long-term climatic conditions, soil types, slope profiles and vegetation types. Commercial geomorphic landform design software tools do not specifically analyze the stability and factor of safety for the computer-designed landform slopes. This research investigated slope stability parameters and factors of safety between a traditional valley-fill design with a geomorphic landform alternative. Slope stability assessments were performed on two profile geometries. Finite-element modeling of a permitted valley-fill and a geomorphic design alternative indicated that slope angle and internal angles of friction associated with the gradation of the overburden greatly affected the designed factor of safety for both designs. The geomorphic designed slopes yielded the highest factors of safety out of 14 models analyzed with all cases having factors of safety over 2.0. The high factors of safety are attributed to shallow slopes and beneficial surface and internal drainage.

Jan 1, 2014

(Read at the Amenia Meeting, October, 1877.) THE Committee on a Standard Gauge have been constantly engaged, since their appointment, in the duties assigned to them.§ They have corresponded with different persons interested in the manufacture and use of gauges in this country, and have received from several of them important information. They have also entered into correspondence with the governments of England, France, Germany, and Russia through their Consuls, and with Austria directly. The Consuls of Germany and France * Transactions, Vol. V, p. 575. t Transactions, Vol. III, p. 43. + Transactions, Vol. II, p. 224. §See Transactions, Vol. V, p.,48.

Jan 1, 1878

By H. Möller, M. Tshibalanganda, C. Taute, A. du Plessis, M. Leary

Additive manufacturing can be used to produce complex and custom geometries, consolidating different parts into one, which in turn reduces the required number of assemblies and allows distributed manufacturing with short lead times. Defects, such as porosity and surface roughness, associated with parts manufactured by laser powder bed fusion, can severely limit industrial application. The effect these defects have on corrosion and hence long-term structural integrity must also be taken into consideration. The aim of this paper is to report on the characterization of porosity in samples produced by laser powder bed fusion, with the differences in porosity induced by changes in the process parameters. The alloy used in this investigation is AlSi10Mg, which is widely used in the aerospace and automotive industries. The sample characteristics, obtained by X-ray tomography, are reported. The design and production of additively manufactured parts can be improved when these defects are better understood.

Apr 1, 2021

By D Martín, G. Díaz, F. Cubeddu, A. B. Mejias

The Modified ZINCEXTM Process (MZP), developed by Técnicas Reunidas, is an industrially proven flexible process. It can handle a wide range of primary and secondary raw materials, producing SHG zinc. The core of the Modified ZINCEXTM Process is the zinc solvent extraction unit. This unit is an effective barrier for any leachable impurities present in the raw material. As a result of this an ultra-pure zinc solution is always obtained. The high versatility of the process makes the application of the technology in different scenarios possible. MZP can be effectively applied when developing a whole new plant (Skorpion) or adapting its scheme to an existing refinery (Akita), in both cases giving the same results. Flexibility in terms of capacity of the plant is a great advantage of the MZP, there is the possibility to adapt the global process to a wide range of production capacities. Zinc production capacities of over 150 000 t/a may be achieved with a single solvent extraction plant train. The robustness of the Modified ZINCEXTM Process has been recently proven on two new plants currently in operation: Portovesme (Italy) and Horsehead (USA) after start up during 2013. The status of both plants is described in this paper.

Jan 1, 2014

The ball level and pulp load play a key role in the operation of industrial scale ball mills. These two operating variables have a significant influence on the performance of the ball mill and any attempts to optimize these devices require manipulating either one or both of these variables. There are several models that can be employed to perform simulations to optimize the performance of industrial ball mills. However, most of these models require ball load and pulp load measurements as inputs to calibrate the model. The changes suggested by the simulator also provide operating regimes that involve moving either the ball level or pulp load and sometimes both of these variables. A ball mill model coded in JKSimMet was used in conjunction with the Sensomag to optimize the secondary ball mill at Waterval concentrator in South Africa. The results show that the perfect mixing ball mill model can be used in conjunction with the Sensomag to optimize the performance of the secondary ball mill.

Sep 1, 2012

By Eugene McAuliffe

HAVING reached the status of an octogenarian plus, I suddenly decided to take a trip to Great Britain by airplane, before the possibility of hardening of the arteries made such a program too precarious. Of thirty June and July days spent in the islands, five were spent in the south of Ireland, or Eire as the politicians like to call their country. On June 15 I arrived in Glasgow where a day was spent with old friends before moving on to Edinburgh, where the Institution of Mining Engineers was billed to hold its summer session. I had received a cablegram before leaving New York inviting me to attend the sessions which I accepted with avidity, spending three most enjoyable and informative days with old friends and the officers of the Institution, Douglas Hay, president; Ian McDermid, secretary; and members of the council.

Jan 1, 1947

By Lyon F. Terry

IN contemplating the prospects of natural gas being transported from the fields where it is produced to such distant points as Philadelphia, New Jersey, New York City, and New England, let us review the advance that natural gas has made and the projects currently scheduled for construction. This may give us a perspective of the point in the long-range development of the natural gas business in which we now find ourselves, and some basis for judging the further expansion of the industry. Authentic statistics of the total marketed production of natural gas in the United States have been compiled by the Bureau of Mines since the year 1906. The growth of the business is indicated by the following data on marketed production for each ten-year interval since 1906:

Jan 1, 1947

By K. C. Dean

During the investigation of the occurrence of manganese deposits in western United States, the Bureau of Mines collected 2-ton samples from three oxide manganese ores in the Columbia and Elberta Mining Districts, Tooelo and Juab Counties, Utah. To determine the amenability of these ores to standard ore-dressing methods: of concentration, extensive laboratory tests were made. The Wildcat property, one of those sampled, is 7 miles east of Fairfield, Tooele County, Utah. The ore is described as a replacement deposit and occurs along fracture and bedding planes of shale and limestone. Experimental work was done on a sample taken from a stockpile at the mouth of the shaft. The Wildcat manganese ore is intermediate in grade (25.7 percent manganese) and contains clay as the principal gangue constituent. A high-grade product was obtained with high recovery of Manganese by simple washing.

Jan 1, 1949

By Niels Verbaan, Ralph Fitch, Charlotte Forstner, David Dreisinger

A process has been developed to extract gold, silver, indium, gallium, lead, copper, zinc, and other metals from a large resource using an oxidizing acid chloride heap leaching technology. The ore is crushed and/or ground to improve reactivity and then contacted with a solution containing NaCl-HCl-NaOCl. The value metals are leached into solution as chloro-complexes. The leachate is treated in a series of separation and recovery processes to produce separate saleable or disposable products. The paper will provide a summary of process development and application to a silver-indium ore from Bolivia. The possible application of the process to other ore types will be presented for discussion.

Jan 1, 2015

By R. T. Pepper

DURING an investigation into the effect of heat-treatment on the creep properties of the magnesium alloy ZW1, (1 pct Zn, 0.6 pct Zr), the previously published methods of final polishing were found to be unsatisfactory. A new diamond-polishing technique has been developed to facilitate the study of fine precipitates in this and other magnesium alloys, and is described in this note. The sectioning and coarse grinding techniques are those of Fox and Hall,' and Hess and Cieorge.' Pre- liminary mechanical polishing is done with 6-µ, and 1-µ( grades of diamond compound on 'Microcloth' using a lubricant of 'Hyprez' oil. When the conventional technique is used with a 1/4- µ diamond wheel for the final polishing of magnesium alloys, scratching is likely to result from the abrasive action of the 'Microcloth' nap on the soft metal surface. This problem has been overcome by the use of a cream on the wheel in order to separate the specimen surface from the polishing cloth. To prepare this cream, a solution of 6-ml tri-ethanolamine in 75-ml water is stirred into 12.5 g stearic acid at a constant temperature of 80° to 90°C. The cream is allowed to cool, and is then 'whipped' to a smooth consistency with 100-ml 'Hyprez' oil. Before polishing, the diamond loaded 'Microcloth' is moistened with a few drops of 'Hyprez' oil, then a small amount of cream is worked into the nap. For the best results a wheel speed of 500 rpm should be used for polishing, and the specimen should be held by hand with a light pressure while being rotated in the opposite direction to the wheel. After polishing it is necessary to swab the specimen thoroughly in methylated spirits to remove residual cream and oil from the surface in order to avoid uneven etching and drying stains. Fig. 1 shows the surface finish obtained on a specimen by polishing on a 1/4- ° diamond wheel using the cream, and Figs. 2 and 3 the precipitate observed in ZW1 after polishing, and etching for two seconds in nitric acid 15 pct in ethylene glycol. This new diamond-polishing technique has made a valuable contribution to the programme of metal-lographic research on ZW1 and has become a routine laboratory practice for other low alloy content magnesium alloys.

Jan 1, 1961

By W. Beres, R. E. Miller, B. Shiari, L. R. Zhao

A dynamic multiscale simulation method has been developed to study the material scratching processes on nanoscale single crystals. The model simultaneously captures the atomistic mechanisms near the free surface and the long range mobility of dislocations and their interactions, without the computational cost of full atomistic simulations. The method also permits the simulation of system sizes that are approaching experimentally accessible systems, albeit in 2D. Simulations are performed on single crystal aluminum to study the atomistic details, surface evolution, and generation and propagation of dislocations for a variety of scratching depths at room temperature. Simulations demonstrate the power of the developed method in capturing both long-range dislocation plasticity and short-range atomistic phenomena during tool advance. Variations of scratching normal and tangential forces are investigated and related to plastic deformation and dislocations generation during the simulation process.

Jan 1, 2006