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By L. Forsbacka, M. Nakamoto, L. Holappa

Viscosity of the slag is one of the central parameters when producing FeCr in submerged arc furnaces. It contributes to smelting behaviour and reduction kinetics of chromite ore as well as to the Cr recovery by influencing the separation of dispersed metal droplets from the slag. A typical FeCr process slag contains 5-10pct chromium oxides, CrO and CrO1.5. The neural network computation was applied to the evaluation of viscosity for slags containing chromium oxides, and the prediction of viscosity in FeCr process slag was conducted. The main results in this estimation were that the chromium oxides in FeCr process slag lower its viscosity, and that the effect of CrO on the viscosity decrease is greater than that of CrO1.5.

Jan 1, 2007

By H. Foster Bain

THERE has never been a great civilized nation which did not have a mining industry; civilization cannot flourish without metal mining. Without tools we can have none of the 'industries that are the foundation of civilization and without metal mining we cannot produce the material of which tools are made. Therefore, if we have no metal mining we have no metals, no tools, no civilization. An example to illustrate this may be drawn from a recent article in the Saturday Evening Post which described the run-down condition of modern Athens. Athens is nothing but a busted mining camp! In its palmy days the Greeks so applied the leasing system to the silver mines of Laurium that the royalties, paid the expenses of government and instead of a tax bill the inhabitants received a pay check. The Persians came over to capture these mines but the Greek navy was built to defend them. When the silver mines played out, Greek civilization declined.. Our mining must continue if our civilization is to continue.

Jan 1, 1921

By J. H. Bain, D. C. Haigh, L. C. Parsons

Jan 1, 1964

By J. G. Pippenger

Rio Tinto Coal Australia (RTCA) developed the Meandu Mine in Queensland, Australia in 1983 to supply thermal coal to the adjacent and newly constructed Tarong Power Station (TPS). In designing the mine, RTCA selected Meandu?s best economic reserves for a 27-year life based on station owner Tarong Energy Corp.?s (TECs) estimated life for TPS. That 27-year plan changed dramatically in the early 2000s when TEC approved life extensions to TPS?s four existing units plus construction of a fifth unit. After reviewing Meandu?s remaining reserves, RTCA decided the nearby Kunioon reserve offered the more economic option for maintaining deliveries beyond 2010. Those plans changed again in 2007 when TEC chose to purchase the Meandu Mine and nearby reserves. TEC then selected Thiess Pty Ltd. (Thiess) to continue operating Meandu until the new mine at Kunioon could be developed. After assuming operation of the mine in 2008, Thiess began a review of Meandu?s remaining reserves and found considerable coal available with economic potential. Working jointly with TEC, Thiess performed several analyses on Meandu and subsequently the Kunioon coal reserves. The results changed TEC?s decision from expediting Kunioon?s construction to instead continuing Meandu?s operation for up to 15 additional years.

Jan 1, 2011

By Dominic Howarth, Diana Drinkwater, Don McKee

At a time when the mining and minerals industry across the world is undergoing unprecedented change, the very fabric of the tertiary education system which is the principal source of trained professionals to the industry is in decline in many countries. The change sweeping the industry is globalisation as evidenced by the emergence of a relatively small number of increasingly dominant corporations with operations in most of the major mining countries. The education sector is struggling to provide sufficient graduates as the viability of small mining schools declines. That is only part of the problem as the global operating industry is increasingly seeking graduates who are comfortable working in different countries and cultures. One obvious response to the industry needs and developments is for the education sector to consider how it can best respond to the global opportunities. This paper presents the case for a global education network which is based on a network of international thinking Universities and which makes use of the latest in educational thinking and technologies to provide a quality education and in the process produce graduates fitted for international careers.

Jan 1, 2003

By K. G. Wheeland, J. E. Dutrizac, M. Wasserlauf, A. A. Condy

Numerous processes for the treatment of thiosalts in base metal milling effluents have been examined in the past decade. Flowsheets for thirteen processes are outlined, and cost estimates are presented for a base case of a 720 mi/h effluent flow containing 1400 mg/L thiosalts. The processes are ranked on the basis of Numerous processes for the treatment of thiosalts in base metal milling effluents have been examined in the past decade. Flowsheets for thirteen processes are outlined, and cost estimates are presented for a base case of a 720 mi/h effluent flow containing 1400 mg/L thiosalts. The processes are ranked on the basis of

Jan 1, 1988

By Terry P. Medhurst, Stuart A. MacGregor, Peter J. Hatherly

In addition to fractures and joints, compositional factors and bedding influence the strength of clastic sedimentary rocks. Rock mass rating schemes must therefore consider all of these factors. In this paper, a rating scheme for clastic sediments based on geophysical measurements is described. Geo-physical logging allows an approximation of rock com-position to be obtained and an assessment of bedding frequency and laminations. Velocity measurements incorporate the effects of fracturing. The rating requires scores for the intact rock, bedding/cohesion, and defects. These are combined to yield a Geophysical Strata Rating (GSR). Determination of the GSR is objective and repeatable. GSR values are typically between 20 and 80 and can be related to the Coal Mine Roof Rating.

Jan 5, 2007

The title of “the world’s biggest volume-produced hydraulic breaker,” that was held for more than a decade by the Atlas HB 7,000, changed hands with the launch of Atlas Copco’s HB 10,000 at bauma 2007. A service weight of 10 t (11 st) and up to 50 percent higher productivity represent major steps toward a new market segment: the use of hydraulic breakers as cost-efficient production machines for primary breaking and as a true alternative to drilling and blasting. The HB 10,000 has all the technical features developed by Atlas Copco for its hydraulic breakers and includes: StartSelect — the breaker’s start-up and shut-down behavior can be adapted to the conditions. AutoControl that ensures an optimized balance of impact energy and impact frequency to maximize percussive performance. Auto-Control also reduces blank firing force and controls energy recovery. PowerAdapt — if oil pressure is too high, the breaker shuts down automatically. This prevents downtime and is particularly useful when breakers are used on different carriers. DustProtector II — a combination of multiple strippers prevents abrasive rock dust and foreign bodies from penetrating the lower breaker section. Conti- Lube II — the automatic lubrication unit guarantees optimal lubrication of the breaker at all times.

Jan 1, 2007

WHEN the writer resided at Zeehan, qn the West Coast of Tasmania, some years ago, he took a keen interest in the geology of the district and availed himself of the opportunity to investigate occurrences, of the varied minerals in which the field abounds. The following notes were compiled as a result of one of his periodical visits to the outlying mining districts, when an examination was made of the bindsay Reward tin mining property, which has an area of 140 acres. This is most easily reached from Renison Bell, the centre of the North Dundas tin-fields, on the Emu Bay railway, 'about' eight miles north east of Zeehan. Thence a pack track some 14 -miles long connects with the mine, crossing the Piemah River by a fine suspension bridge.The mine itself is situated on the main south leading spot of the Parson's Hood Range, at an altitude of some 1600 ft. above sea level. The Parson's Hood Range is composed of granite and is an extension of the rugged Meredith Range. A remarkable feature is the uniform topography of the surrounding country when viewed from the peaks. Except where dissected by the rivers and creeks, the surface is practically level and, indeed, affords a striking illustration of an ancient uplifted peneplain.The mine has been opened by means of trenches and adits, and the ore-body proved to extend for a length of 30 chains, with an average width of about 100 ft. Its general trend is west-north-west, and its dip, which is steep, corresponds to that of the country-rocks. These latter, which are of sedimentary origin and generally regarded as of pre-Silurian age, have been tilted at high angles, consequent, no doubt, on the crustal movements produced by the intrusion of the huge granitic masses which now form the high ranges in the vicinity.It may be here remarked that it is not Within the scope of this paper to deal with the sequence of events leading to the geological structure...

Jan 1, 1923

By W. L. Ott, J. E. Hawley, C. L. Lewis

"IntroductionTHE APPLICATION of spectrochemical analysis to metals of the platinum group was advocated by Harvey (3) as follows: ""The spectra of the platinum group metals have been studied less than many of the more common metals. The rarity of occurrence of these elements makes the analysis relatively unusual. Potentially, the analysis of this group is an excellent application of spectrographic methods, particularly in contrast to the tedious chemical procedure"".Wichers (8) divides platinum-metal analysis into three broad divisions as follows :( 1) The detection and estimation of these metals in other materials, e.g., ores, where the amounts present are very small.(2) The detection and estimation of impurities in the refined metals themselves ....(3) The analysis of alloys of the platinum metals .....The present paper deals with the second division: analysis of refined rhodium.Research on spectrochemical techniques for determination of trace contaminants in refined platinum metals was begun at Queen's University in 1949, under the supervision of Professor J. E. Hawley. Since 1953, the work has been continued in the Metallurgical Laboratories of Falconbridge Nickel Mines, Limited. Techniques for spectrochemical analysis of refined platinum and palladium have been published ( 4, 5). A technique for analysis of refined iridium has been developed but not yet published."

Jan 1, 1955

By Jeon Jeon, Yong-Kun Choi, Chung-In Lee, Yong-Hun Jong, Hag-Soo Kim

In this study, a computer program to design tunnel blasting pattern has been developed. The program consists of two parts; one is for tunnel blasting pattern design and the other is for blasting modeling to estimate the peak particle velocity, the distribution of fragmentation and the excavation damage zone. We modified the design method of tunnel blasting pattern suggested by Langefors because it provided undesirable pattern in blasting practices such as considerably large center cut and too large burden for Vcut as drilling length increased. As a result, the burden and spacing were reduced to practically appropriate amounts. In addition, the correlation between rock mass rate, RMR, and rock constant in blasting, c, was analyzed based on the data collected from twenty three tests of tunnel blasting. It was concluded that the correlation between them was fairly good enough to be applied in cut design. In order to check the validity of the modified methods and their practical applicability, test blasting was carried out at two different tunnel construction sites in Korea. The results were satisfactory in that the average rate of advance was 90% and the overbreak did not cause additional support. Futhermore, the developed program is capable of estimating peak particle velocity by using (a) the existing vibration equations, (b) the vibration equation obtained by test blasting to check out the practical applicability of the designed blasting pattern. Feedback is implemented into the program to adjust the designed blasting pattern and control the vibration.

Jan 1, 2005

By C. S. Wageman

Staying competitive in the highly aggressive Powder River Basin is a challenge facing all operators. Any advantage that a mine utilizes to improve productivity and reduce costs could mean the difference in the tight spot coal market. Technological advances in mining equipment and data acquisition at the Eagle Butte Mine in Gillette, Wyoming result in productivity gains and increased maintenance awareness. A new overburden haulage truck fleet with an onboard payload and fault monitoring system interacts via telemetry with the loading shovel and PC's located in production and maintenance offices, enabling staff to monitor production and maintenance on a real-time basis. This paper will describe the system and highlight the benefits realized as a result of its implementation.

Jan 1, 1996

By G. S. S. Raman, M. S. Klima

Coal refuse slurries stored in tailings impoundments can potentially lead to environmental concerns such as effluent seepage, property devaluation, and in extreme cases, dam failures. Pressure filtration offers an opportunity to reduce the impoundment requirements by providing significantly drier solids. A full-factorial design was used to study the effects of temperature and pH on dewatering a refuse slurry obtained from a coal preparation facility in Pennsylvania, USA. The experimental results indicated a strong effect of temperature on cake moisture as the cake moisture after about 2800 s was 22% at 43 °C and only 36% at 10 °C for tests conducted at pH 3. ANOVA results confirmed the statistical significance of pH, temperature, and their interaction effect. Also, the results showed no significant differences between the tests conducted near neutral and alkaline pH values at low and ambient temperatures. On the other hand, Tukey’s test indicated higher reductions in cake moisture at higher temperatures for lower pH values. This study affirms the need to monitor and control the pressure filtration process as throughput could significantly vary with changes in temperature and slurry conditions.

By G. S. S. Raman, M. S. Klima

Coal refuse slurries stored in tailings impoundments can potentially lead to environmental concerns such as effluent seepage, property devaluation, and in extreme cases, dam failures. Pressure filtration offers an opportunity to reduce the impoundment requirements by providing significantly drier solids. A full-factorial design was used to study the effects of temperature and pH on dewatering a refuse slurry obtained from a coal preparation facility in Pennsylvania, USA. The experimental results indicated a strong effect of temperature on cake moisture as the cake moisture after about 2800 s was 22% at 43 °C and only 36% at 10 °C for tests conducted at pH 3. ANOVA results confirmed the statistical significance of pH, temperature, and their interaction effect. Also, the results showed no significant differences between the tests conducted near neutral and alkaline pH values at low and ambient temperatures. On the other hand, Tukey's test indicated higher reductions in cake moisture at higher temperatures for lower pH values. This study affirms the need to monitor and control the pressure filtration process as throughput could significantly vary with changes in temperature and slurry conditions.

Jun 17, 2019

By G. S. S. Raman, M. S. Klima

Coal refuse slurries stored in tailings impoundments can potentially lead to environmental concerns such as effluent seepage, property devaluation, and in extreme cases, dam failures. Pressure filtration offers an opportunity to reduce the impoundment requirements by providing significantly drier solids. A full-factorial design was used to study the effects of temperature and pH on dewatering a refuse slurry obtained from a coal preparation facility in Pennsylvania, USA. The experimental results indicated a strong effect of temperature on cake moisture as the cake moisture after about 2800 s was 22% at 43 °C and only 36% at 10 °C for tests conducted at pH 3. ANOVA results confirmed the statistical significance of pH, temperature, and their interaction effect. Also, the results showed no significant differences between the tests conducted near neutral and alkaline pH values at low and ambient temperatures. On the other hand, Tukey’s test indicated higher reductions in cake moisture at higher temperatures for lower pH values. This study affirms the need to monitor and control the pressure filtration process as throughput could significantly vary with changes in temperature and slurry conditions.

By S. Shi, J. Y. Hwang, B. Li

Silver, copper, and zinc are commonly known elements with antibacterial and antifungal capabilities. Attempts have been made to dope silver on minerals, glass, and ceramics and the resulting materials have been investigated for their antibacterial and antifungal properties. Since silver is expensive and very reactive, silver doped materials have been found inappropriate in some applications. Copper-vermiculite is investigated as an alternative. Vermiculite has high cation exchange capacity on the magnesium ion in the crystal structure. Copper ion may have a high tendency to replace magnesium because of similar charge interference and ionic radius. Copper-vermiculite is prepared by reacting vermiculite and copper chloride solution. By impregnating copper ions into the nanometer openings between the layers of vermiculite, it is possible to render the composite with antibacterial functions if the copper ions could be released gradually from the composite. The antibacterial efficiency of Cu-vermiculite against Escherichia coli was studied using the Halo method. The results show that Cu-vermiculite is effective for preventing the reproduction of the bacteria. Heat treatment of Cu-vermiculite at up to 400°C does not show significant changes in antibacterial activities.

Jan 1, 2002

By Francesco Montanari, Gianni Schena

"Recent improvements in X-ray computed tomography allow investigation of objects several tens of millimetres in dimension with spatial resolutions in the order of a few microns. These improvements are made possible by coupling the micro-focus technology adopted by some of the latest cone-beam X-ray sources with an increase in the efficiency of the detectors. The micro-focus technology allows the production of clearer images at high magnification by reducing the penumbra (fuzziness) associated with larger focal spot size.Even higher resolutions can be expected in the next few years with the commercialisation of nano-focus X-ray tubes. In practice one can inspect a system of fine composite particles and analyze the different mineralogical phases in each individual particle. Computed tomography allows accurate liberation studies, e.g. providing liberation spectra or washability data in tens of minutes. However, on-line application of micro-focus computed tomography is unlikely in the foreseeable future, despite rapid development.Dual-energy (DE) radiography is another X-ray technique, which allows retrieval of the volumetric content of valuable components in two-phase particles in a fraction of a second. A digital radiograph of a single two-phase particle produces a grey level image, where the luminosity of the pixels is determined by the sum of the attenuation levels of all the structures. Thus morphological and compositional effects concur to produce the radiographic image, which does not allow retrieval of the composition of the particle, as the 3D-structure of the particle is compressed into a 2D-image, with an obvious loss of information. Thus, in principle it is not possible to discriminate between thick, comparatively penetrable, and thin, comparatively impenetrable mineralogical components."

Jan 1, 2003

By Kazimierz Gwizdala

In recent years, in Poland the ATLAS piles have been successfully applied for some constructions near Gdansk. The piles have been used as foundations for housing and another areas of civil engineering, in delta Vistula geotechnical region, characterized by weak, highly compressible soils represented by mud and peat, lying in sub-surface layers, several meters thick. Usually below are dense sandy soils or gravel. In all cases, the base of ATLAS piles rested on sandy soils. The analysis of pile bearing capacity has been discussed and verified by static pile load tests (SPLT). The load-settlements characteristics obtained were satisfactory. In the paper, the results of geotechnical investigations as well as calculations and load tests are shown. The ecological aspects of ATLAS piles application within highly urban areas of the cities and complex geotechnical conditions are emphasized.

Jan 1, 2006

By George Rice

Foreword Following the explosion in the Hillcrest mine, which occurred in the evening of Sunday, September 19th, 1926, and in which two men lost their lives, the writer was invited by the Hon. J.E. Brownlee, Premier of Alberta, to conduct an investigation into the causes of the disaster, and to make such recommendations as seemed advisable with a view to minimizing as far as possible the chance of future explosions in this and similar Alberta coal mines. Accordingly, the mine was visited, and extensive investigations were made underground on October 21st, 2.2.nd, and 25th, in company with Mr. John T. Stirling, Chief Inspector of Mines for Alberta, Mr. Moses Johnson, District Inspector for the Crowsnest Pass District, Mr. J as. A. Richards, Inspector of Mines, Edmonton, and also Mr. Thomas Davies, manager, and other officials of the Hillcrest mine. Hearings of the coroner's inquest were also attended on October 20th and 23rd, when testimony regarding the explosion was given by various witnesses. The following paper summarizes my general observations in tracing the place of origin of the explosion, and my efforts to determine the cause of ignition. Certain recommendations arc also made, and the writer invites discussion on these and the other matters dealt with in the paper.

Jan 1, 1928

By James P. Stewart

This case history describes the engineering design and construction for the Contractor of a 35-ft-deep excavation for an 800-square-foot addition to an existing sewage pump station. The site posed unexpected geotechnical complications that included deep gravelly soil, a history of local construction difficulties, groundwater consisting of heavy salt brine, and the need to underpin the existing pump station. The project took an interesting twist when the Owner issued a change order limiting the dewatering discharge to a fraction of that required to lower the water table. This documents the interesting circumstances of this job and documents the unusual subsurface conditions in the Syracuse, NY Lakefront area.

Jan 1, 2003