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By E. G. Noble

The effects of HBr concentration and temperature on the solubility and hydration state of AlBr3,' CoBr2, PbBr2, MnBr2, KBr, and NaBr were investigated by the Bureau of Mines. Saturated aqueous solutions of the AI, Pb, K, and Na bromides were sparged with HBr gas at 20°, 40°, and 60° C, and saturated solutions of Co and Mn bromides were sparged at 20° C. Increased HBr concentration caused decreased salt solubility because of the common ion effect for all the investigated bromides except PbBr2. Aqueous solubilities at 20° C were, in percent, 51.7 for AlBr3, 53.2 for CoBr2, 1.1 for PbBr2, 59.6 for MnBr2' 39.5 for KBr, and 47.4 for NaBr. At 60° C, the solubilities were, in percent, 53.3 for AlBr3, 2.2 for PbBr2' 46.0 for KBr, and 53.8 for NaBr. Solubilities in solutions sparged to HBr saturation at 20° C were, in percent, 0.5 for AlBr3, 42.0 for CoBr2, 32.2 for PbBr2, 21.0 for MnBr2, 0.6 for KBr, and 0.3 for NaBr. At 60° C, the solubilities at HBr saturation were, in percent, 1.8 for AlBr3, 41.4 for PbBr2, 1.3 for KBr, and 0.4 for NaBr. CoBr2 precipitated out to a minimum solubility of 27.2 pct at 28.7-pct-HBr concentration. Further increases in HBr concentration increased CoBr2 solubility because of the formation of bromide complexes. PbBr2 in-creased in solubility as HBr concentration increased.

Jan 1, 1988

By Marcela Morvová, Mário Janda, Morva Imrich

"The possibilities of greenhouse gas mitigation using various methods are brought out. The special case of utilization of mixture of CO2 with other greenhouse gases in a synergetic way inside non-thermal plasma based system is described in detail.Measurements on pilot system comprising pyrolysis chamber as alternative energy system (production of hydrogen and liquid tar) were made for various biomass and waste as the input material. The exhaust from this system was treated with non-thermal plasma gap suitable for up to 650Nm3/hour of exhaust gas flow. Condensable portion of exhaust is liquefied in distillation unit; produced hydrogen is stored on-line inside nano sized carbon of our own production.The CO2 removal efficiency varies depending on exhaust composition between 45 to 98%. Other oxides as CO, NOx, SOx and several hydrocarbons and VOC are also removed. The main product connected with CO2 removal is a solid powder of proteinoid nature. There exist strong probability, that precursor of the origin of life on the Earth from primary atmosphere were formed in the similar way as it is present in the electric discharge system used. Our system is equipped with on-line as well as ex-post analysis of all forms of products. We have also developed a system for recuperation of all forms of produced heat. It is stored inside as latent heat of waxes.IntroductionNatural greenhouse effect on the Earth is caused mainly by water vapour with the average absolute concentration about 4%. Other gases able to absorb long-wave radiation and thus this causing greenhouse effect are CO2, CH4, N2O, halocarbons and as precursors ozone and NOX. Some of them we produce and introduce into atmosphere in large quantities during production of energy and in transport. This factor leads to permanent increase of average temperature of air, sea and oceans, so called global warming.Nowadays large amount of data exists showing that the temperature of Earth in the last 150 years has been continually increasing. It represents about 03°C per ten years and the most of climatologist believe, that the increased concentration of greenhouse gases in the atmosphere is responsible for this effect.The most important greenhouse gas is carbon dioxide CO2. Majority of CO2 emissions comes from electric power stations working with fossil fuels, cars and industry. Burning of fossil fuels contribute up to 80% to world wide anthropogenetic emissions of CO2."

Jan 1, 2010

By L. E. Schultze

The Bureau of Mines operated a mineral recovery unit to recover metal values from post-flash geothermal brines from the Salton Sea known geothermal resource area as part of its research into the use of plentiful resources. The brine was available for metals recovery after its heat content had been used to generate electricity. The brine source was treated with lime to precipitate the contained iron, manganese, lead, and zinc before injection of the heat-depleted brine into the underground reservoir. Data are presented on the effects of process variables, such as rate and method of lime addition and air oxidation versus air exclusion. Variations in precipitation of metal values, composition of precipitates, effectiveness of slurry thickeners, and methods of treating the precipitates to recover metal values are discussed.

Jan 1, 1982

By C. Okrusch, C. Roos, M. Akers, S. Rosenthal

Modern mining consistently faces controversy. Public sentiment impacts the permitting and development of mines, so a quality public relations (PR) program for mining companies may improve society’s impression of the mining industry. Developing mines face more permitting challenges than operating mines, which stems from a lack of societal trust given the history of mining and its impact on the environment. Two case studies were selected based on the type of public controversy they face to demonstrate how pervasive permitting issues are in industry. Both Pebble Mine, owned by Northern Dynasty Minerals (NDM), and Black Butte, owned by Sandfire Resources America Inc (SRA), experienced difficulties with their water permitting due to potential risks their mine developments posed to local fish populations. Pebble has, to date, failed in all of their attempts to become permitted due to concern for the water and the fish. Black Butte dealt with the same problems, on a smaller scale, but was able to become permitted. These two mines will be discussed in detail including local history, mine setting, mining history in America, prevalent culture groups, technology development, and intercultural communication competence (ICC). The mining industry needs to evaluate its ICC skills since ICC directly determines the effectiveness of PR. Based on Barna’s Stumbling Blocks for intercultural communication, methods for improving the mining industry’s PR will be suggested in the hope of easing the permitting process for future mines by developing ICC.

Mar 2, 2022

By Melinda Channel, Alan W. Weimer, Jonathan R. Scheffe

"There is a need to develop cost effective renewable energy processes for the production of clean fuels that can simultaneously mitigate the U.S. energy/global environmental security issue. If H2 can be obtained cost effectively via the splitting of water using concentrated sunlight, then it’s possible to operate a fuel cell using renewable H2 or to synthesize other fuels based on renewable H2 for generating electricity or for running internal combustion engines. For example, H2 can be reacted with sequestered carbon dioxide (CO2) to produce syngas (H2/CO) via reverse water gas shift (RWGS), i.e. H2 + CO2 ? CO + H2O. The syngas can be catalytically methanated to form synthetic natural gas (SNG) or it can be catalytically reformed to produce liquid fuels such as “green” gasoline via the MTG process (syngas? methanol ? gasoline). The desert SW United States is home to world class sunlight. Fundamental ferrite thermodynamics will be reviewed, an example of the beneficial effect of ferrite surface area on reaction kinetics will shown, and process economics will be investigated for a 100,000 kg/day facility to produce H2.Introduction and Background ThermodynamicsSpinel ferrites of the form MxFe3-xO4, where M generally represents Ni, Zn, Co, Mn, or other transition metals, have been shown to be capable of splitting water according to the two step cycle shown below:MxFe3-xO4 + solar thermal energy ? xMO + (3-x)FeO + 0.5 O2 (1)xMO + (3-x)FeO + H2O ? MxFe3-xO4 + 2H2 (2)This is an inherently clean and sustainable process, as the only net inputs are solar energy and water, and the net outputs are hydrogen and oxygen. Ferrite water splitting cycles are advantages compared to other high temperature water splitting cycles, such as the ZnO/Zn and Mn2O3/MnO cycles, because thermal reduction has been demonstrated at significantly lower temperatures[1, 2]. As a result, overall efficiency may be increased due to the fact that radiation losses increase as the fourth power of temperature, and material considerations for reactor design should be more flexible. Additionally, cycle repeatability has been demonstrated with relative ease as compared to other thermochemical cycles [3-6]. However, the amount of hydrogen per mole that is generated is significantly less than for other high temperature thermochemical cycles due to the fact that only Fe3+ is capable of being reduced at the temperatures of interest[6]. In addition, water oxidation kinetics appear to be very slow, likely due to diffusion or surface area limitations created by near surface oxidation [6, 7]."

Jan 1, 2010

By X. Cao, J. J. Jonas, Wanjara. P., J. Gholipour, E. Dalgaard

The linear friction welding (LFW) behaviour of near-ß titanium alloy Ti-5Al-5V-5Mo-3Cr (Ti- 5553) was investigated. Microhardness measurements were performed in order to evaluate the mechanical properties of the welded material. The linear friction welded (LFWed) Ti-5553 was examined with optical microscopy and scanning electron microscopy (SEM) to evaluate the microstructure’s response to the thermomechanical conditions. Characterization of the welds included analysis of the microstructural features of the weld region and thermomechanically affected zone (TMAZ) in relation to the parent material.

Jan 1, 2010

By Walter Nelson

Considerable thought and discussion had been devoted toward provision for increased milling capacity at the Allenby concentrator of The Granby Consolidated Mining, Smelting and Power Company operations as early as 1940. During the war, plans for the installation of an additional grindi.ng unit were formulated but were not carried out. It took considerable time after the war to prepare the mine again for its highest rate of production since, with the scarcity of men, development work had been sacrificed in favour of maximum ore shipments. In order to prepare for the expected competitive market in copper, the matter of increasing the capacity of the concentrator was again given serious attention. As ore became available in the mine and the output of the mill was increased, limitations for a satisfactory recovery were observed, due to the overloaded condition of the classifier units at the higher tonnages. From a metallurgical standpoint, the ore from the Copper Mountain mine had always been difficult to treat on account of the finely disseminated character of much of the mineralization and the difficulty of grinding to the desired fineness. This trouble has become aggravated with time as an increasing amount of wall-rock has diluted the ore and lower grade orebodies have been mined. It therefore has been, and is, the practice at the concentrator to maintain the maximum amount of reduction in size of material fed to the flotation units as is possible for the daily tonnage to be milled. This means that all the grinding units are operated for the maximum possible time, and that the classifiers are regulated to return as much feed ?as possible to the mills. The number of tons to be milled for ?the day is determined by the concentrator superintendent after ascertaining the availability of ore from the mine, the condition of the concentrator ore bins, and the need for repairs in the rolls plant. In order to maintain the tonnage des1red, hourly estimates are made of the rate of grinding by weighing the amount of ore contained on one foot of each of the belts conveying the feed to the various ball-mills, and adjustments are made accordingly.

Jan 1, 1950

By L Keeney

Geometallurgy is not a mechanism designed to replace current geological and metallurgical deposit characterisation but an added component required to understand orebody variability. Current geological characterisation approaches focus on understanding deposit genesis aimed at identifying new mineralised regions and metallurgical characterisation determines parameters required for engineering design of processing plants. Geometallurgical integration has the task of drawing on aspects of each stream to enable spatial mapping of performance indices across a deposit. It is a complimentary activity to current practice and adds a new dimension to orebody knowledge. Although the notion of conducting an integrated geological and metallurgical analysis is not a new concept, limited publications exist in the field proposing integrated methods, with several technical issues existing in current geometallurgical integration approaches. An iterative method drawing on existing geological and metallurgical characterisation and new measurement tools and inputs is proposed. The integrated method comprises of discrete components dynamically linked together through iterative feedback loops with each component having a specific purpose achieved by applying a range of data acquisition technologies and statistical tests. The key outcomes of the method are:overcoming the lack of optimised geometallurgical domains relevant to processing performance,development of a rigorous approach to identifying parameters controlling processability,improved protocols for relevant metallurgical test data and sample selection, andability to generate greater data support to enable rigorous geostatistical modelling of geometallurgical attributes. This paper outlines the integrated mapping and modelling method developed and draws on multiple data acquisition technologies applied within the AMIRA P843 GeMIII Project.

Sep 5, 2011

By Andre Panteleyev, Charels S. Ney, John M. Anderson

"Sam Goosly prospect, 22 miles southeast of Houston, B.C., was discovered in 1967 through geochemical reconnaissance. Soil sampling interpreted with respect to an east-to-west ice movement led to drilling targets.Mineralization is in a window of rocks thought to be Hazelton Group surrounded by Tertiary volcanic rocks and intruded by two stocks separated by about one mile. A westerly quartz monzonite stock is dated 61.1 m.y. and an easterly gabbro-monzonite complex is dated 52.5 m.y. The Tertiary volcanics are trachyandesites shown by the B.C. Department of Mines and Petroleum Resources to be in part extrusive equivalents of the gabbro, and they overlie Hazelton rocks uncomformably. Copper-molybdenum mineralization is sparsely developed in the westerly stock. Silver-copper mineralization forms an elongate west-dipping slab between the stocks in Hazelton rocks, which are continuously pyritized. The gabbro stock is not mineralized, but some dikes related to it are slightly so. Tertiary rocks are pyritized, but are not known to carry copper-silver mineralization. Hazelton rocks are divided into a lower conglomerate, an intermediate pyroclastic unit and an upper mainly sedimentary unit. They form a west-facing homocline. Coppersilver mineralization resides in the pyroclastic unit, mainly in a massive dust tuff through which are lenticular units of lapilli tuff. Well-mineralized rock is typically a breccia of light fragments in a dark chlorite-sulphide matrix. Sulphides are pyrite, chakopyrite and locally pyrrhotite, with very minor tetrahedrite, s phalerite and other sulphosalts. Rock alteration is predominantly a pervasive pyrite-sericite type, with widespread tourmaline, scorzalite, gypsum, ankerite and traces of fluorite. The most evident control of the copper-silver mineralization is the gross parallelism, over a strike length of 1.5 miles, to Hazelton strata, particularly a massive dust .tuff unit. In detail, mineralization crosscuts bedding and there is no appreciable banding within sulphides . A strictly syngenetic origin is untenable, but some initial concentration in a volcanogenic environment with subsequent modification by thermal processes seems likely."

Jan 1, 1972

Reduce dust at the auger mine face by modifying airflow patterns, around the minim machine. Approach Limited clearance between an auger miner and the mine root restricts airflow across the face and causes dust rollback. Directional sprays arc used to direct air across the face, thereby reducing dust rollback and increasing dust dilution (fig. 1). Laboratory and underground studies were used to test and optimize effectiveness of the directional sprays. Results of Laboratory Study Laboratory experiments were conducted in a simulated auger gallery equipped with a full-scale mock auger miner and bridge conveyor. A dual curtain configuration was used to direct the, ventilation, which averaged 2,700 cfm throughout the experiment. Testing variables included spray location, pressure, spacing, orientation, and number. Figure 2 shows the optimized directional spray system, also called the auger clearer spray system. The system consists of three sprays mounted alone the intake side of the miner. Sprays arc spaced 16 to 24 inches apart, and angled 30° toward the return side of the miner. The 24-inch spacing moved about 7% more air across the face than the 16-inch spacing; however, it resulted in some additional misting on the return side of the miner. A 30° orientation was more effective than a 60° orientation for moving air across the face and minimizing misting on the return side of the miner. Flat fan sprays arc used because their spray paths arc not obstructed by the top of the miner and mine roof, A 50° fan angle is used to minimize misting on the intake side of the miner.

Jan 1, 1989

The Douglas mineral sands deposit is located 75 km north of Hamilton in western Victoria, Australia. The deposit was discovered in the late 1990s by Basin Minerals Limited and purchased by Iluka Resources Ltd in 2002. Prestrip mining commenced in December 2004, with ore mining commencing in August 2005. Douglas is the first of several projects being implemented by Iluka Resources Ltd in the Murray Basin, with all heavy mineral concentrate planned to be treated at the companyÆs mineral separation plant in Hamilton. The mineralisation at Douglas lies along the south-eastern margin of the Murray Basin. It is hosted by marine Pliocene Loxton-Parilla Sands and consists of three discrete deposits; Bondi Main, Bondi West and Bondi East. The mineralised sediments dip at a low angle to the west and lie unconformably beneath a veneer of top soil (50 - 100 mm) and subsoil (up to 600 mm) and between three to 12 m of overburden. The barren overburden, characterised by high clay content (<53 ¦m material) generally provides a stark contrast to the sandy ore, which is between 1 m (parts of Bondi East) and 15 m (Bondi Main) thick. Both overburden and ore are removed utilising standard dry mining techniques using both scraper-bulldozer and truck-excavator combinations. All ore is delivered to run-of-mine (ROM) stockpiles before being reclaimed by front end loader into the processing plant. Grade control at Douglas is based around visual dig control aided by high precision survey, which enables accurate reference to the resource drilling and block model data. Vertical excavator faces, inclined scraper faces plus regular test pits and trenches provide opportunities for in pit mapping and sampling. This data is used to refine not only the resource estimate for Douglas but also the drilling, interpretation and resource modelling methods used for similar deposits across the basin. The foundations of the geological reconciliation process at Douglas are the in pit surveys undertaken each time the mining fleet has completed building a ROM stockpile. These surveys and the subsequent interrogation of resource models enable robust estimations of the heavy mineral content of the stockpiles, which are subsequently used to predict the daily input grades into the plant during their reclamation. Reconciliation of this daily data is then undertaken at the end of each month against metallurgical production data and plant balances. Learnings and results from the reconciliation process are used to further refine subsequent resource models and modelling methods.

Jan 1, 2009

By S. Mohanta, S. Chakraborty, B. C. Meikap

"An air dense medium fluidized bed separator is an efficient dry process for the removal of undesirable gangue material from run-of-mine coal. Its cleaning performance depends on a variety of operating parameters that are interrelated in unknown, complex ways. A literature review showed that these parameters' effects had been experimentally investigated using a traditional one-variable-at-a-time approach, which is highly inefficient and sometimes misleading because many of the parameters often interact with each other to alter the overall equipment performance. Also, it is realized that the interrelationship among these parameters can have a significant effect on equipment performance. Therefore, to correctly evaluate the effects of individual parameters as well as their interactional effects on the separation performance of an air dense medium fluidized bed, we conducted a scientific study based on response surface methodology. Empirical models for two key response variables, namely, product ash and combustible recovery, were developed and subsequently used for identifying an appropriate operating region to achieve optimum separation performance. Furthermore, the optimum performances predicted from the empirical models were validated against experimental data. Preliminary results show a strong interaction among the operating parameters investigated in this test program.IntroductionFluidization is widely applied in industry for its various useful features. In the coal industry, it is used in the air dense medium fluidized bed (ADMFB) separator for the beneficiation of run-of-mine coal. In this separator, a medium is created by suspending fine magnetite particles in an upward air flow, and this pseudo-fluid is used as the beneficiation medium, with the lighter coal particles floating to the medium’s surface while heavier particles sink to the bottom. This separation technique had been receiving a significant amount of attention worldwide in recent times for its specific advantages of low operating cost and less restriction for small capacities (Luo and Chen, 2001; Sahu et al., 2009; Dwari and Hanumantha Rao, 2007; Van Houwelingen and de Jong, 2004), but it is still not a well-established industrial practice because of the availability of efficient wet processing technology. However, with a revival of interest in the dry beneficiation of coal, in general, and ADMFB, in particular, there is once again a concerted effort to improve the efficiency of the ADMFB process, and successive improvements have been made to make this process a competitive and viable option. The existing literature reveals that most of these research efforts had been essentially focused on the identification of a single parameter that has a key influence on separation performance, without taking notice of parameter interactional effect. For example, Luo et al. (2004) proposed a pressure drop number to distinguish separation performance without considering the bed height and gas velocity, which are intimately related to this proposed pressure drop number."

Jan 1, 2015

By J. Raatikainen, I. Auranen

"INTRODUCTION Sorting technology has advanced rapidly recently. Of the two possibilities particle sorting has advanced especially in introducing new sensors and the use of multiple sensors. The analyzing and computing lead times have also shortened. This has made it a viable technology option for many applications but not for the most important sorting task at a mine; the run-of mine ore. Bulk sorting, however, has advanced in smaller steps, even if the technology has the capability to tackle the run-of-mine ore and offers a high potential to bring mines substantial economic benefits. The sensors, which are useful are restricted by the difficult operating conditions or by the ore characteristics. One of the important features of run-of-mine sorting technology is the major material handling infrastructure required. The capital expenditure can be substantial requiring good understanding of the sortability curve (grade-recovery curve) behavior of the ore. This paper discusses one industrial case, where substantial amount of data measured from the ore feed belt has been obtained. This data was then analyzed for the grade recovery curves obtainable from that ore with sorting. EXPERIMENTAL The XRF measurement used was the FCA device from IMA Engineering (Fig.1). It is a specially built version of XRF designed to operate with coarse material. The measurement was situated at the main belt conveyor taking ore from the primary crusher to the stockpile. The crushed ore was about 80% -300 mm at a capacity of 1100-1200 tph (Fig.2). Measurement times were varied from 30 seconds to a minute. Measurements were obtained over several months.As the XRF is a surface distribution measuring technique, the measurement was first tested upon accuracy and reproducibility against plant daily wet chemical assays and against on-line Courier feed analysis. As there is a varying delay in the ore stockpile, the delay time was used as a variant in the validation. Different measurement times were tested for accuracy. A one minute measurement time gave a total measurement relative standard error, which was both for Cu and Ni below 3%. The results showed also very robust correlations; for Cu, the correlation coefficient was R > 0,94 for one minute measurements over three months and R > 0,86 for Ni respectively. Fig 3. Shows a measurement period of two hours showing substantial feed grade variations (given as relative value; 1.0 represents the mean value during the measurement month)."

Jan 1, 2018

Valuers of mineral properties should be aware that accountants are a major user of their opinions of value. Reliance by accountants can range from obtaining comfort that book values in balance sheets are not overstated to establishing values by which to assess the fairness of a takeover offer. Accountants using mineral property valuations clearly can't be expected to have the same level of expertise as the valuer and ""second guess"" the valuation. But they do have an obligation, under the ASC guidelines and their own professional standards, to'check the logic and reasonableness of the valuation before being able to rely on it. This means reviewing the valuation report for general sensibility, discussing the methodologies and assumptions with the valuer and being satisfied as to his competence and independence. This paper outlines how accountants use mineral property valuations, the level of scrutiny applied to such valuations and the problems commonly encountered in practice by accountants seeking to rely on them. The paper also explains how values of-mineral properties are established in company balance sheets and why these often differ, quite validly, from fair market values.

Jan 1, 1994

By W. W. Mein

IN March 1949 the Calaveras Cement Co. was sued by five landowners whose properties are located in the vicinity of the plant. These landowners—all of them cattle ranchers—sued for dust damages of $120,338 and for an injunction preventing the company from casting dust upon their properties in injurious quantities. The issue was split, the jury deciding the amount of damages and the court handling the injunction features. The action came to trial before a jury in April of that year and resulted in damages being awarded in the amount of $7,508. A month later the court issued its injunction requiring recovery of stack dust to an 87 pct minimum. The Calaveras plant, shown in Fig. 1, is located three miles from San Andreas in the heart of the Mother Lode country, about 45 miles east of Stockton, Calif. Since it is in a small town, the company's responsibilities to its employees and to the community are different from those of plants located in large centers of population. Construction of the plant was begun in 1925, and production was started the following year. Standard gray Portland cement as well as several specialty cements are produced. Production facilities have been continually enlarged so that the present capacity is more than double what it was 25 years, ago. The most important item in the company's expansion program was the purchase in 1945 of an 11 ft 3 in. x 360 ft Allis-Chalmers kiln which had been declared surplus by the Defense Plant Corp. The company is now able to produce about 2,500,000 bbl of cement a year, and employment at the plant is approximately 300. The production of cement has always involved a dust problem, solution of which has been attempted in a number of different ways. By far the most efficient method of catching dust discharge is electric precipitation. Soon after the company went into production in the 1920's, the landowners near the plant began complaining about dust discharge. The company settled the matter by paying them a total of $27,000 for dust damages incurred during the period from 1929 to 1938. In the latter year the two-unit Cot-trell Electric Precipitator shown in Fig. 2 was installed and collected over 85 pct of the dust resulting from operation of the two 11 ft 3 in. x 10 ft x 240 in. kilns. From 1938 until 1946 the landowners registered no objection and were apparently satisfied with that dust recovery. In 1946, however, the substantially higher production resulting from operation of the new kiln immediately overtaxed the facilities of the existing two-unit precipitator. In a short time claims for dust damages were again received from the landowners. The company informed them that because of postwar shortages it would take several years to install a new precipitator. The company stated that it intended to purchase an additional precipitator and offered in the meanwhile to pay the landowners a fair amount to cover their damages. This offer was rejected and the landowners filed suit in the Superior Court of Calaveras County asking for total damages of $120,-338 and for the injunction outlined above. Case for the Ranchers The attorneys for the plaintiffs produced three different types of witnesses: first, the landowners themselves and members of their families; second, other cattle raisers who were sympathetic to the plaintiffs; and third, several types of technical experts: veterinarians, soil chemists, and an aerial photographer. The testimony of these witnesses was designed to establish that the flue dust from the plant had not only damaged the land and the forage, but had also caused fluorine poisoning to their animals. By a combination of these causes, the plaintiffs attempted to prove substantial loss of profits.

Jan 1, 1952

By Ahmad Abdollahi

Many factors affect mechanical properties of hypoeutectic Al-Si alloys. As examples the presence of impurities such as Mn and Fe due to the formation of intermetallic phases, additions of small amounts of alkaline earth metals and cooling rate in consideration of Si formation, they all have an impact on mechanical properties of hypoeutectic Al-Si alloys. In this investigation, the effect of Fe content into the specification range of A357 alloy, the addition of different modifiers consisting of Na, Sr and Ca for the alloy of A356 and different mounting techniques for separately cast test coupons of hypoeutectic Al-Si alloys using the lost wax method were studied. The results showed that using material with lower Fe content and addition of modifiers improve mechanical properties. Also different mounting techniques resulted in different mechanical properties.

Jan 1, 2004

By Robin B. Batterham

"Since the 1970?s we have seen a marked corporate response in terms of the environment. In part this has come from regulation but it has largely come from stakeholders and the community. Rising expectations have in general been met. We now see a similar trend towards sustainability. At the same time, the importance of mining to the share market has decreased drastically and with that decrease has come the requirement for the mining sector to show returns similar in manner to other sectors. While rationalisation can achieve some progress towards these goals, the long-term requirement is for innovation, as it always has been. This paper looks to the logical goal of innovation within a sustainable mining framework and targets the removal of the desired metal values with minimal environmental footprint. It is suggested that broad ranging alliances will be necessary, particularly amongst the R&D suppliers, to achieve this goal. Industry will need to take an active role given the recent global restructuring.THE MARCH TO SUSTAINABILITYSince the 1970?s there has been an increasing corporate response on environmental matters. We have moved from matters environmental being issues relevant only to minority groups through a series of attitudinal changes by management. Whilst there have always been examples of excellent environmental performance, for many in the 70?s spending money on improving the environment beyond some minimal level was seen as a distraction from production or treated in a similar way to donations to the community. There is little of that attitude these days, as most mining companies have long since regarded the environment as a core business direction. Indeed, for some years one could note an escalation in matters of environmental reporting to the extent that the environmental performance of companies is now very public. In some cases, NGOs have even been invited to help certify and audit the reporting standards. Similarly with health & safety.There is now a rising expectation on the part of the community that social matters will also be given the same level of support as health, safety and the environment. This time around it would appear that the mining industry is at the leading edge of sustainability. The Global Mining Initiative (Global Mining, 2002) and the contributions to the Rio World Summit on Sustainable Development (Rio +10, 2002) suggest that sustainability is being taken very seriously by the mining industry. For sustainability it is convenient to use the Brundtland (1987) definition. This definition has widespread acceptance with governments, industry, environmental groups, financial institutions and individuals as a direction against which our activities and plans can be measured."

Jan 1, 2003

By J. W. Miller

An investigation was begun by the Bureau of Mines in 1948 to determine the preparation characteristics of American coals. Results of the investigation were planned to be reported on a county basis and, from the data developed, to determine: (a) Which coals, either as mined or after beneficiation by conventional preparation, are suitable chemically under present standards for producing metallurgical coke. (b) Which coals require special and more intensive treatment in preparation than is now practiced. (c) Which coals cannot be considered potential sources of metallurgical coke, regardless of preparation. This report is one in a county series and describes the preparation characteristics of the coals of Logan County, W. Va. According to present-day standards for metallurgical coal, many believe that the sulfur content of the coal should not exceed 1.25 percent? Coal with more than this amount has been used for making metallurgical coke, especially when blended with coal containing less sulfur. In this series of reports 1.25 percent sulfur is used as a gage to determine whether or not a coal will be suited for metallurgical coke.

Jan 1, 1957

By S. L. Weber, Y. H. Cheng, D. E. Banks, J. K. H. Ma

"The aggressive industrialization of America, the development of powered tools which generated massive amounts of respirable-sized dust particles, a latency period which may mask the relationship between exposure and development of disease, inadequate (or perhaps even careless) understanding of the relationship between dust exposure and disease, and respiratory protection which has later proven to be inadequate have resulted in a series of epidemics of silicosis which have caused the premature death of many workers.1-11 Emphasis on the regulatory control of dust levels in the workplace has greatly reduced the development of pneumoconiosis in the United States and in other developed as well as underdeveloped countries, yet the prevention of silicosis or coal workers' pneumoconiosis has not come close to being accomplished. Despite the public health perspective that pneumoconiosis arc totally preventable illnesses, there appears to be little evidence that this is the case.Cases of pneumoconiosis continue despite aggressive enforcement policies by regulatory agencies, attempts at dissemination of very readable materials aimed at workers and management 12.13 and respiratory dust exposure standards which are in place and appear, for the most part, protectivc.14- 16 It is more than frustrating for all parties associated with advocating workers' health to see reports of workers with aggressive silicosis. On another level, both the physician and the affected worker are helpless when a diagnosis of silicosis or coal workers' pneumoconiosis is made. Both realize that there is no proven way to affect the natural history of these progressive inflammatory and fibrotic processes. Neither is there any ""compassionate use"" therapy. What must be developed, at the very least, is a ""salvage therapy"" which has the potential to reverse, or at least dramatically lessen, the aggressive natural history of silicosis which develops over relatively short time periods. Because of the aggressive nature of silicosis (compared to coal workers' pneumoconiosis) attempting to develop a therapy for this illness should be a priority."

Nov 1, 1995

By M. Gangal

CANMET-MMSL, in cooperation with Dry Systems Technologies and Quinsam Mine, conducted a study to determine the effects of B50 biodiesel on the emissions of a flameproof diesel power package in comparison with mining diesel fuel for application in underground coal mines. The emissions testing for coal mine application requires that the intake air mixture to the engine should be at 1.25 percent methane by volume in air. The tested power package system included a naturally aspirated, mechanically-controlled diesel engine with a diesel oxidation catalyst (DOC), a heat exchanger, flame arresters, and a low temperature disposable diesel particulate filter. The engine dynamometer tests were conducted at the CANMET-MMSL Diesel Emissions Research Laboratory in Ottawa using the ISO 8178-C1 test protocol. The separate and combined effects of a B50 biodiesel blended fuel, and with and without 1.25% methane enriched intake air were measured on a diesel power package. Fuelling the baseline engine (without methane), with B50 biodiesel blend reduced carbon monoxide (CO) by 44%, and increased nitrogen dioxide (NO2) by 19%, and particulate matter by 31% relative to the mining diesel fuel. Similarly, injection of 1.25% methane to the intake air for baseline engine with mining diesel fuel increased engine power by 15%, CO by 124%, and NO by 15%, and decreased NO2 by 13%. The effect of B50 biodiesel relative to the mining diesel for coal mines application (with methane for both fuels) was to reduce CO by 27%, and NO by 6%, and increase NO2 by 23%, with no change in engine power. The overall results indicate that the minimum ventilation rate for the equipment application in coal mines with B50 biodiesel was 4.11 m3/s (8,700 cfm), slightly higher than the ventilation rate of 4.01 m3/s (8,500 cfm) with the mining diesel fuel. This slight increase in ventilation rate for B50 biodiesel fuel was due to an increase in NO2 at one of the operating test points, and the ventilation rate for this equipment was governed by NO2 in the exhaust gas.

Jan 1, 2009