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By A. Robles-Vega

In recent years, tellurium has been extensively used in the manufacture of semiconductor materials. For this type of application, high-purity tellurium is required. Selenium, lead and silicon are usually the main impurities in tellurium. During the electrolytic refining of copper, tellurium gold and silver are collected in the anode slimes. A pyrometallurgical treatment is used to recover gold and silver from the decopperized anode slimes whereas tellurium is oxidized and skimmed off from the refining furnace as a Na2CO3-based slag. In the slag, tellurium is present as sodium tellurite (Na2TeO3), which is further water-leached from the slag. The first step in the conventional process for tellurium recovery consists of the precipitation of the tellurium contained in the leaching solution as tellurium dioxide (TeO2). The solid TeO2 is then dissolved under acidic conditions for its further reduction with sulfur dioxide gas (SO2). In this paper, an alternative route for tellurium production is presented in which a sodium tellurate [Na2TeO4] intermediate is obtained by oxidation of the sodium tellurite in an alkaline solution following the water leaching step. Sodium tellurate is then dissolved in acid media and high-purity tellurium is obtained by reduction with SO2 gas. Experimental tests under laboratory conditions indicate that the novel process yields higher precipitation selectivity for tellurium than the conventional process. A comparison of its efficiency concerning impurities co-precipitation with respect to the conventional process is discussed.

Jan 1, 2009

By Ihsan Berk Tulu, Ted Klemetti, Deniz Tuncay

"The Analysis of Retreat Mining Pillar Stability (ARMPS) program was developed by the National Institute for Occupational Safety and Health (NIOSH) to help the U.S. coal mining industry to design safe retreat room and pillar panels. ARMPS calculates the magnitude of the in-situ and mining-induced loads by using geometrical computations and empirical rules. In particular, the program uses the “abutment angle” concept in calculating the magnitude of the abutment load on pillars adjacent to a gob.In this paper, stress measurements from U.S. and Australian mines with different overburden geologies with varying hard rock percentages were back analyzed. The results of the analyses indicated that for depths less than 650 ft, the ARMPS empirical derivation of a 21° abutment angle was supported by the case histories; however, at depths greater than 650 ft, the abutment angle was found to be significantly less than 21°. In this paper, a new equation employing the panel width to overburden depth ratio is constructed for the calculation of accurate abutment angles for deeper mining cases.The new abutment angle equation was tested using both ARMPS2010 and LaModel for the entire case history database of ARMPS2010. The new abutment angle equation to estimate the magnitude of the mining-induced loads used together with the LaModel program was found to give good classification accuracies compared to ARMPS2010 for deep cover cases.INTRODUCTIONIn the early 1990s, the Analysis of Longwall Pillar Stability (ALPS) was introduced by Mark (1990) as a chain pillar design software and was generally accepted and used by the U.S. coal mining industry. Following the success of ALPS, the National Institute for Occupational Safety and Health (NIOSH) developed the Analysis of Retreat Mining Pillar Stability (ARMPS) program for designing retreat mining pillars using a similar approach as ALPS (Mark and Chase, 1997). The Australian mining industry also recognized the success of ALPS, and Colwell, Frith, and Mark (1999) calibrated the program to Australian conditions. The ALPS and ARMPS programs draw their strengths from the large databases that are used to calibrate them (Mark, 2009). However, following the Crandall Canyon Mine collapse in 2007, NIOSH had to reconsider the pillar design criteria used in deep-cover retreat mining (Mark, 2010). The ARMPS overburden load prediction algorithm was improved to more accurately predict the loading of narrow panels with high overburden depths by implementing the pressure arch concept, and this new version is called ARMPS2010."

Jan 1, 2019

By Richard J. Waxweiler, Frank E. Lundin, Robert J. Roscoe, Victor E. Archer, Michael J. Thun, Joseph K. Wagoner

[Introduction] Since excess lung cancer mortality was first noted in the late 1800's among Joachimsthal-Schneeberg miners, there have been a number of studies of the long term health effects among various types of miners exposed to elevated levels of radon and its radioactive decay daughters. Substantial excesses of lung cancer have been noted among miners in the Joachimsthal mines (Sevc, 1976) , lead-zinc miners in Sweden (Axelson, 1979) , fluorspar miners in Canada (DeVilliers, 1971) , iron miners in Sweden (Renard, 1974) , uranium miners in Canada (Hewitt, 1976), and metal (Wagoner, 1963) and uranium miners in the United States (Lundin, 1971; Archer, 1976). The latter prospective cohort has also been shown to be at an excess risk of death due to tuberculosis, nonmalignant respiratory disease, and accidents when followed through September 30, 1974 (Archer, 1976). This report extends the followup of this cohort of miners through December 31, 1977 and expands the mortality analysis to investigate more cause-specific categories. [Methods] During the decade beginning with July, 1950, medical teams from the United States Public Health Service (USPHS) examined 3362 white and approximately 780 nonwhite males who had worked underground in uranium mines in the Colorado Plateau at least one month by January 1, 1964. Occupational, medical, and smoking histories were obtained during the examinations and often updated/confirmed during subsequent annual censuses of the miners conducted by the USPHS. The white miners now have been followed-up through December 31, 1977 using the Social Security Administration, Internal Revenue Service, direct telephoning and various other sources. Death certificates were obtained for the deceased and coded directly into the Seventh Revision of the International Classification of Diseases, Adapted, using the rules in effect at the time of death. Deceased miners for whom no certificate has yet been located were assumed dead on the date specified by the reporting agency, cause of death unknown. The uranium miners cohort was analyzed using a modified life-table system developed by the National Institute for Occupational Safety and Health (NIOSH). Person-years at risk of dying (PYAR) were calculated for each miner from his first USPHS medical examination date or date upon completion of one month of underground uranium mining if that was later. PYAR were calculated specific for five-year age groups, calendar periods, and periods after first underground uranium mining. The numbers of cause-specific observed deaths among the cohort occurring by December 31, 1977 were compared to the numbers of expected deaths. The expected deaths were calculated by multiplying the appropriate PYAR by the United States death rates for white males specific for five-year age groups, five-year calendar periods, and cause. The results were summed over the age and calendar period specific categories to obtain the total expected deaths for each cause. Standardized Mortality Ratios (SMR's) were calculated for each cause by dividing the observed number of deaths by the expected number of deaths and multiplying by 100. In some tables, two-sided 95% confidence intervals for the SMR's were computed using either Fisher exact confidence limits, if the observed frequency was less than eight, or approximate confidence limits, if the observed frequency was eight or greater, to indicate statistical significance. Because a priori hypotheses had been well established, one-sided lower confidence limits were used for tuberculosis, lung cancer, other nonmalignant respiratory disease (ONMRD), accidents, and total mortality. [Results] The cohort included 589 miners first examined in either 1950, 1951 or 1953; 753 first examined in 1954; 1235 first examined in 1957; 5 first examined in 1958; and 782 first examined in 1960. In Figure 1 the distribution of the cohort by first year of underground uranium mining indicates that 13.7% started before 1947 and would have thus had an opportunity to be followed beyond 30 years

Jan 1, 1981

By Don F. Macfarlane

This paper describes the field application of the NTH fracture classification to rock encountered in the construction of the 9.6 km long, 10m diameter, Second Manapouri Tailrace Tunnel. Excavation of the tunnel was undertaken by TBM between 1997 and 2002, in gneisses, granitic and diorite rocks. The paper outlines an adaptation of the NTH fracture classification used during the geological logging of this tunnel. The NTH fracture classification was primarily applied to assess discontinuity spacing for tunnel support requirement decision-making. The paper includes some general comparison of NTH classes with overall penetration rate.

Jan 1, 2008

By S. B. Patton

A computer model, which quantitatively utilizes the relationship between the interactive and dynamic processes of methane drainage, mining, and ventilation, is presented. The model includes simulation of the coalbed methane reservoir for prediction of gas-emission rates under the influence of degasification wells and longwall mining, ventilation network-generation, and ventilation simulation. As mining progresses step-wise through the coalbed-methane reservoir, the ventilation network is created and subsequently simulated, iteratively determining fan requirements to safely reduce methane concentrations. The model can be used to quantitatively study the effectiveness of methane degasification on the ventilation system in a longwall panel.

Jan 1, 1992

By A. Yazadni-Chamzini

Considering the nature of open pit mines, harvest volume, it usually is required to remove a lot of waste to access to mineral planned grade. So, one of the most important part of open pit mines design, is waste dump site selection. Many factors are effective in waste dump site selection. These factors are sometimes in conflict with each other. So selecting the desired location for waste dump is a process complex and multi-criteria decision making. There are a variety of methods for decision making under complicated condition, such as fuzzy, Delphi, multi-criteria decision making and Expert system methods can be hinted. VIKOR method, which is one of the decision making multi criteria methods, is useful tool for decision-making. On the other hand with regard to uncertainty in decision-making, fuzzy approach is a useful tool for this purpose. This article has tried to select the best waste dump site in Sari Gunay Gold Mine by Fuzzy VIKOR. The results show that C position has a higher priority than other positions.

Jan 1, 2012

By J. L. Mehaffey

A variety of chemicals offered by Armak were evaluated as dewatering aids for aqueous slurries of silica sand, sparsand and feldspar; an established commercial dewatering aid was used as a control. A number of Armak's potential dewatering aids yielded lower moisture retention values than did the commercial product on all of the mineral samples. In addition to the chemical dewatering evaluations, some of the mechanisms involved in the removal of water from these mineral samples were examined.

Jan 1, 1983

By Norman F. Schulz

The technical excellence of separation achieved in a mineral concentration process, or any other process where two constituents of any kind are physically separated from each other, is expressed uniquely and quantitatively by the Separation Efficiency: ES = (R ? Rg) where R is the percentage of the valuable constituent and Rg the percentage of the waste appearing in the concentrate. The Separation Efficiency meets all the usual requirements of a true efficiency and is independent of the nature of the process used. It can be visualized as the percentage of the feed material that, in effect, actually undergoes complete separation while the rest of the feed is distributed randomly and unchanged into the two separation products.

Jan 1, 1969

By O. MacIntosh

The Round Mountain gold mine, located 90 km (55 miles) north of Tonopah, NV began large-scale production in 1977. During 2008 Round Mountain Gold Corp. (RMGC) relocated the primary crusher facility approximately 300 m (1,000 ft) to make room for the next phase of openpit mining activities. This facility was installed in 1988 and used a log-crib retaining wall and dump pocket. RMGC selected Hilfiker Retaining Walls and Collins Engineers, Inc. to provide design and materials for a new 17-m- (56-ft-) high mechanically-stabilized embankment (MSE) wall to support the haul trucks at the new location. The construction contractor was EarthTech West Ltd. of Norwood, CO. An MSE wall with a cast-in-place concrete face was chosen as a durable, yet less expensive alternative to the reinforced concrete dump pocket that was originally designed for the project. The arrangement of the MSE wall is of an unusual configuration to meet a variety of operational and maintenance requirements. This paper outlines the selection process, design and construction of the MSE wall.

Jan 1, 2010

By S. A. Pirzada

A thermal plasma assisted laminar flow reactor has been used to evaluate the kinetics of converting alumina to sodium aluminate in flight. Free energy minimization calculations were used to determine experimental conditions. The experimental variables include: alumina particle size, alumina/sodium nitrate molar ratio, temperature and residence time. A mathematical model for the conversion was developed and validated. Experimental and mathematical results are presented.

Jan 1, 1996

By R. W. Smith

The electrokinetic and flotation behavior of the green alga Chlorella vulgaris was studied in the absence and presence of Pb(II), Al (III) and flotation collectors. It was found that the presence of Al (III) is necessary for good flotation of the organism whether or not Pb(II) is present when dodecylammonium chloride or sodium dodecylsulfate is used as collector. Best flotation using dodecylamine is at about pH 8 and best flotation when using sodium dodecylsulfate is at about pH 4. It appears because of the small size of the organisms that the Al (III) is necessary for flocculation to enhance bubble-cell contact and C. vulgaris removal from water. When N-dodecyl-2-aminoproprionic acid is used as collector good flotation occurs at about pH 4 without the addition of Al (III).

Jan 1, 1990

By Peter Hall

The need for large volume covered storage has increased drastically in the last ten years. Increased world demand for such products as thermal coal, potash, metallic concentrates, etc., availability of land for large open storage and environmental issues have brought about this need. This paper discusses briefly demand, environment, types of covered storage and the Alternative Storage System "Eurosilo", a proven system for storage of dry bulk mateials in units up to 100,000 m3.

Jan 1, 1982

By III Boxley

Most of us realize that our nation's roadways are under ever-increasing stresses, from higher traffic counts to increased tire pressures and their resulting loads. At a time when the interstate system as originally envisioned is completed, and the National Highway System is being drawn to replace it, it is appropriate that we examine design and construction methods for the next century. The stone industry shares a common desire to produce high quality, cost-effective roadways that perform over time. The superior sub-grade and road base structure provides for the superior roadway. Since I am neither an engineer nor a contractor, I will not attempt to suggest design or construction methods. What I can do is share my company's experience in supplying road base materials by using a historical perspective in Virginia and some trends in the market that we have observed. Road building and related non-building construction are still far and away our largest markets as an industry. If we can help to improve the end product of our biggest customers, we add value to our own product. Indeed, in a time of budget constraints and competing demands for government dollars, we must show value over the life of a pavement structure to ensure their long-term funding.

Jan 1, 1996

By J. S. Hall

The productivity and fuel efficiency of iron-ore blast furnace operations has greatly increased in recent times. These improvements, particularly to the Japanese steel industry, have primarily arisen from process engineering studies of the blast furnace and associated operations such as sintering. The development of fluxed sinter based on iron-ore fines reacted to produce highly reducible, low slag sinters has contributed further to a reduction in fuel requirements. The Pilbara province of Western Australia is a significant source of these iron-ore fines supplied to the international market. Increasingly, this market is being offered high quality ores from other foreign sources. To technically assist companies in improving the processing efficiency of ores, and to improve the technical marketing of ores by modelling the processing characteristics of Australian/international ore blends, the Commonwealth Scientific and Industrial Research Organization (CSIRO) is actively assisting the industry by researching the general theme of 'iron ore from mine to metal in this paper we outline progress towards a numerical description of: a. ore deposit classification. b. Degradation during transport. c. Direct reduction of iron ore. d. Liquid bath ore reduction/smelting. e. Industrial sintering.

Jan 1, 1986

By B. A. Ferguson, P. W. MacMillan

INTRODUCTION Jack Spalding in Deep Mining, Chapter 3, states: "In deep mining, to start stoping an orebody without a definite plan of operations covering the whole extraction from beginning to end is to invite serious trouble. Any stoping without plan is bound to leave, toward the end, a number of pillars, remnants, or promontories, which, as they are reduced in size, are liable to fail and cause a general collapse. The object of stope planning is so to mine an orebody that at no stage in the operation is a remnant left. Definition: `When a block of ore is stoped in such a way that eventually a small piece is left entirely surrounded by stoping, that piece is termed an island remnant.' The design of and adherence to a plan of stoping is of greater importance in preventing rock bursts than the type of ground control adopted." This, of course, is just an example of the old axiom that an ounce of prevention is worth a pound of cure. And in this context, mining does not have to be very deep before poor ground conditions, made worse by lack of good planning, force a mining company to resort to more expensive methods of ore recovery. At all times when rock pressures become excessive, stoping plans must be devised to avoid the creation of pillars or promontories. This is most readily recognized when mining deep narrow ore veins by open methods. It would be a little more general to say that stoping systems should seek to avoid or minimize localized concentrations of rock stress. Ore bodies, and particularly those at Falcon¬bridge, can reach large widths and leaving pillars for extraction at a later time cannot be avoided. However, good planning can reduce the effect of factors which create bad ground conditions. The necessary ingredients of planning are time and information: time to formulate and revise ideas; information, gained in exploration and early development, to provide the fullest knowledge of the ore body. In this way, plans become meaningful. It must always be kept in mind that the long-term results of good planning often require decisions not compatible with reaching earliest full production. PLANNING FOR DEEP MINING At Falconbridge Nickel Mines ore bodies presently being found and prepared for production lie at depths in excess of 610 m (2000 ft) below surface. Current un¬derground exploration is being directed towards favor¬able locations below 914.4 and 1219.2-m (3000 and 4000-ft) depths, at most mines. The Onaping Deep ore body has been traced to a depth of 1508.8 m (4950 ft) and at Falconbridge mine the ore body is under develop¬ment below the 5000 level. Planning for more efficient ground control has therefore become an important con¬sideration of future mining. HYDRAULIC BACK FILLING AND CUT-AND-FILL STOPING The advent of hydraulic back filling has led to the increasing use of flat-back cut-and-fill stoping methods during the last ten years, until it has probably become the commonest method of mining deep ore deposits in Canada. These methods account for almost all the pro¬duction from Falconbridge Mines at this time. The ad¬vantages claimed are: safety-a minimum of open ground; very little supplementary ground support (except rockbolted backs and walls); greater selectivity and flexibility in extraction (horizontal extension of the vein, high grade ore stringers going out into the walls); and high productivity and increased mechanization in larger ore widths. There is some difference of opinion as to whether hydraulic classified tailing back fill provides any great resistance to initial closure of the stope walls. The evi¬dence available suggests that it does not. Addition of portland cement to the back fill just prior to placement has produced a material having the properties of a weak concrete. It is confidently expected that this material will assist greatly in the efficient mining of pillars and generally in giving increased ground support to oppose closure. PRINCIPLES OF STOPE PLANNING BY LONGITUDINAL FLAT-BACK CUT-AND-FILL Again quoting from Spalding: "The practice of con¬trolling output by stopping and starting stopes is bad¬stopes once started should proceed without interruption, and control must therefore be obtained by altering the rate of stoping. It is therefore necessary that faces should normally advance at a medium rate which can be boosted, if required, to give temporarily a greater output. Modern high productivity stoping methods, however, generally aim to achieve and maintain the maximum output possible from a stope. Control of tonnage and grade, therefore, becomes a more complex problem requiring very careful scheduling and organiza¬tion. With the basic method of flat-back overhand stoping using hydraulic fill, it is not usually possible to mine in such a way as to avoid creating pillars." Consider an ore body as illustrated in Fig. 1. It is 274.3 m (900 ft) high by 228.6 m (750 ft) long on strike and averages 4.6 m (15 ft) in ore width. It rep¬resents approximately 907 000 t (1,000,000 st). The ore body could be mined by advancing one long single face through all the levels from bottom to top. A total face length of 228.6 m (750 ft) would accommo¬date five 45.7-m (150-ft) stopes. See Fig. la. Each of these stopes would produce approximately 1814 t/m (2000 stpm) and the ore body would require a period of ten years for complete extraction. A possible im¬provement to this scheme might be to stagger the indi¬vidual stope faces. See Fig. 1b. Problems of hanging wall failure can be reduced by this arrangement. From the point of view of reducing travelway maintenance, it is good practice to employ a stoping system of retreat. Stopes farthest from the shaft are mined first so that on completion, haulage drifts below can be aban

Jan 1, 1982

By Chi-shing Wang

In many cases the roof strata of a bedded deposit may be considered as a composite of rock beams of rectangular cross section, whose component layers differ in thickness and may or may not be separable from each other when they are subjected to loading by their own weight. An analytical study of the behavior of such multiple-layer beams is extremely difficult owing to the heterogeneity and anisotropy of rock materials. The complexity is revealed by the fringe photographs obtained from several series of barodynamic photostress experiments conducted on various types of multiple-layer model beams of a medium-grained Bedford limestone. Further discussion on the applicability of barodynamic photostress techniques to the model study of the behavior of mine roofs in stratified geologic media is presented by comparing the phenomenological observations recorded in this investigation.

Jan 1, 1968

By X. Cui, H. Ding, J. Wen, Q. Gu

This study is a continuation of previous work designed to further explore the mechanism of the bioleaching of sulfide concentrate at neutral pH by heterotrophic bacteria Bacillus megaterium QM B1551. The concentrate contained 13.2 percent nickel (Ni) and 0.2 percent cobalt (Co), which presented primarily as pentlandite and pyrrhotite. Contact and noncontact bioleaching experiments were conducted with finely ground ore at an initial pH of 6, resulting in 44.7 percent of Ni and 38.2 percent of Co leached in the contact-bioleaching treatment. Oxidation experiments of sulfur, thiosulfate (S2O32−) and ferrous ions (Fe2+) by cell membrane were performed to verify whether sulfur transferase, thiosulfate quinone reductase and enzyme cytochrome B558 on the surface of the bacteria could be expressed to oxidize the sulfide. The results show that thiosulfate quinone reductase and cytochrome B558 could be expressed to oxidize S2O32− and Fe2+ to SO42− and Fe3+, respectively.

By E. Sabina Brady

Over the next two decades there will be significant trade and development opportunities in China for mining, engineering, equipment, and construction companies interested in becoming part of the development of China's chemical and fertilizer industries. At last count, China's phosphate ore reserves of 11.8 Gt (13 billion st), ranked fourth in the world behind the US, the USSR, and Sahara-Morocco. However, a recent statement by the head of the Ministry of Geology and Minerals, Sun Daguang, claims that with increased prospecting in the last few years, China's phosphate reserves now rank first in the world. Whatever the actual size of its known and potential reserves, China's present phosphate processing capabilities fall far short of demand, while the substantial progress that has been made in this area points out the severity of the problems that still remain. Since 1949 China has developed 181 mines and increased its phosphate concentrate production from 10 kt (11,000 st) to 10.86 Mt (11.97 million st). By the 1980s, China was the third largest chemical fertilizer producer in the world-although this claim is slightly misleading as China's nitrogen/phosphate potassium ratios are far from average world ratios and even further from US standards. According to the Sixth Five Year Plan promulgated in 1982, the country's development plans emphasize the expansion and upgrading of key energy and industrial sectors, including that of fertilizer production-specifically phosphate and potash. Within the framework of the plan, the Ministry of Chemical Industry's development priorities are to: • Increase potash production by 150% to 50 kt (55,115 st). • Raise phosphate fertilizer production 21.2% to 2.8 Mt (3.1 million st), 46 kt (50,705 st) of which will come from new projects constructed and completed within the Sixth Five Year Plan, with projected new production of phosphate concentrate and complex fertilizer in the next decades totaling 500 kt (551,146 st). • Commence work to increase phosphate ore production by 8.33 Mt (9.18 million st). Facilities for 2.43 Mt (2.68 million st) will be completed and come on stream by 1985. • Commence work to increase iron pyrite ore production by 3.69 Mt (4.07 million st), facilities for 2.9 Mt (3.2 million st) will be completed and come on stream by 1985. • Verify 600 Mt (661 million st) of new phosphate ore reserves. Since the promulgation of the Sixth Five Year Plan, Chinese authorities have announced that 70 key construction projects will receive top priority in the implementation of the plan. These projects include five in the chemical industry area, including the construction of four fertilizer plants in Urumqi (Xinjiang), Zhenhai (Zhejiang), Beijing, and Lucheng (Shanxi), and a pyrite mine in Yunfu (Guangdong). In addition, by 1985 the state will expand or construct three major phosphate mines: Wangji in Hubei, Kaiyang in Guizhou, and Kunyang in Yunnan. Fertilizer Ratios In 1982, China's fertilizer production was slightly higher than 12 Mt (13.2 million st) and consisted of 80% nitrogen, 19% phosphate, and 0.19% potassium. By 1985, state officials project that fertilizer production will reach 13.4 Mt (14.8 million st) and consist of 78.4% nitrogen (10.5 Mt or 11.6 million st), 21.2% phosphate (2.8 Mt or 3 million st), and 0.39% potassium (52.3 kt or 57,605 st). To attain the world average using the country's 1985 projected production level for nitrogen, China will have to double its 1985 phosphate production to 5.76 Mt (6.35 million st) and increase its 1985 potassium production almost 80 times to 4.1 Mt (4.5 million st). These numbers demonstrate the seriousness of the fertilizer production problem in China today and the long-term nature of the problem's solution. Development Examples Yunnan is the third largest phosphate-rich province in China with verified deposits of 1.9 Gt (2.1 billion st). Despite this abundance, the province only mines around 3 Mt (3.3 million st) of phosphate rock annually. In June of this year, Yunnan announced its intention to initiate 39 development projects within the next two and a half years, requiring an estimated $200 million worth of foreign investment. The three areas receiving the most emphasis will be:

Jan 9, 1983

By R. Bauer

Adaptations and redesign of the existing already very successful and proven road milling machine concept and technical innovations such as an optimized, specifically for mining application developed cutting drum, cutting housing design and cutting tools, high manoeuvrability achieved via a tight turning radius, a three disk clutch system and a cutting drum drive that allows for the acceptance of higher loads, a complete reinforcement of the chassis to withstand higher vibrations and torque, the installation of increased engine power via a modern drive unit, a specifically for mining/construction applications developed operator’s platform and finally a redesigned air intake system and the adaptation of the levelling system resulted in far more cost effective and advantageous capabilities of Wirtgen Surface Miner in soft to medium hard mining and construction applications. As the achieved results show for the first time in modern surface mining history mechanized cutting is capable to compete successfully against traditional drill, blast/ripping and other conventional mining methods.

Jan 1, 2007

By Jacob Petersen, Jon J. Kellar, Samuel Kessinger, Kiran Green

 The paper demonstrates that Belle Fourche Shale (BFS), an abundant shale, can be transformed into a ceramic through careful characterization and thermal processing. The study explores the potential of BFS ceramics for use as refractories and thermal energy-storage devices, highlighting their high thermal storage capacity, good thermal shock resistance, and cost-effectiveness.

Dec 1, 2023