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With the proving of a mineable orebody at Orlando in May 1961, Peko Mines N.L. was faced with the decision of whether to mill the ore on site or to haul it 25 miles to central facilities at Peko. Orlando was a relatively small orebody, so that it was decided to haul, although no reliable assessment of possible ore haulage costs was available.The necessity for a good haul road was recognised from the beginning and a 17 mile, 12 ft wide, single seal bitumen road was constructed, to link the mine to the Stuart Highway and Peko. The initial selection of 20 ton capacity diesel-powered end-tipping ore carts was made, with the best information available at the time.Since then some 130,000 tons of ore have been carted over a period of 3 years, and this paper presents the experiences of this haulage operation and the lessons learned.A second mine has just been brought into operation at Ivanhoe, 19 miles from Peko. For this haul it was decided to use an ore haulage vehicle of the side tipping road train type, which would cart some 70 tons, or more than three times the load of the vehicles initially selected.Only about 5,000 tons had been hauled at the date of this paper, but preliminary figures indicate a cost 01 1· 65d./ton-mile as against 2·47d. for the smaller vehicles.It would appear that the road haulage of ore from small outlying mines to a central plant can be highly economical, if certain basic rules concerning haul roads and vehicle selection are followed. This paper does not try to determine the maximum tonnages and haul distances which would finally make road hauling uneconomical...

Jan 1, 1966

By W. J. Theron

The purpose of the paper is to give an introduction to the concept of fatigue and its causes in the mining industry. By knowing the fundamental role it plays, together with its dynamics, can positively contribute to a mine?s safety management system. The difference between physical and psychological fatigue will be addressed with a possible range of causes that could trigger fatigue. There are two main sources of fatigue: firstly, work-related fatigue which is associated with activities at the workplace; and secondly non-work-related fatigue. The shared responsibility between the employer and employee is also discussed as it involves factors that occur both in and outside the workplace. Employers have the responsibility to manage fatigue through using a risk management approach. Employees have the responsibility to ensure they get enough sleep, take sufficient and regular nutrition, are healthy and physically fit and come to work fresh and alert. The impact of the implementation of a fatigue management plan and procedures has the potential to eliminate employee fatigue or its causes, reduce the likelihood of fatigue occurring in the workplace, and counteract the effects of fatigue when it occurs. Factors considered when implementing a fatigue management system include: extended hours of work, shift work, time of day and work design. Fatigue is one of the major role players (either causal or contributory) when it comes to causes of fatalities in the mining industry. Our main challenge in identifying whether fatigue played a role is the fact that it cannot be tested in post-mortems like drug or alcohol abuse. It is an aspect worth understanding and getting an organization sensitive to managing it properly to benefit both organizational as well as employee needs. Keywords Signs of fatigue: Causes of fatigue, circadian rhythms, the fatigue equation, fatigue management, fatigue affecting safety, fatigue fighting tips, lifestyle suggestions.

Jan 1, 2011

By Philip Dubbeling

Conventional dynamic sheetpiling techniques are ill-suited to urban development because of the emission of excessive noise and ground vibrations. Drilled shafts and slurry walls alleviate some of these environmental concerns but add additional problems due to large bulky machines, reliance on dusty concrete plants and urban trucking grief. To solve these problems, pre-fabricated sheetpiles are hydraulically jacked-in by reaction principle using a compact and lightweight press-in machine, a so called the "Silent Piler". Through scientific analysis, definition and systemization of press-in machines and methods, new construction concepts such as the one-step approach, implant structures, functional design and life cycle design have been developed to comply with new basic construction principles.

Jan 1, 2006

The Karangahake gold-silver deposit is located 11 km west of Waihi in the southern part of the Hauraki Goldfield. Historically it was the second largest bullion producer in the goldfield with a past production (1882 - 1944) of 126.712 tonnes of gold-silver bullion (Au:Ag ratio of 1:3.3) from 1 142 315 tonnes of ore grading 27.4 g/tonne gold equivalents.

Jan 1, 1987

By Kristen E. Coose

Concrete is a mixture of a fine aggregate (sand), a coarse aggregate (gravel), cement, and water. Cement itself is the most expensive of the ingredients but generally amounts to only about 10% of the concrete mixture. Cement raw materials include calcium, alumina, iron oxide, silica, and gypsum. They are heated and chemically changed into clinker "minerals," which are then ground and shipped as cement. Each of the four main clinker minerals-tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite-impart specific strength and compositional properties to the final concrete product. During hydration of the cement, chemical changes produce new minerals that include calcium silicate hydrate gel (C-S-H, the main constituent of hydrated cement paste), calcium hydroxide, and calcium, sodium, potassium, and sulfate ions, among others. Two main reactions can occur that may be deleterious to concrete. Normal cement pore solutions, in a hydrated cement, contain sodium hydroxide and potassium hydroxide. If these alkali concentrations are too high, they can react with the siliceous aggregate (alkali-silica reaction, or ASR) to form an alkali-rich calcium silicate hydrate gel (C-N+K-S-H), which, upon prolonged contact with water, can expand to crack the concrete. The other deleterious reaction occurs when the mineral ettringite (Ca6A12(S04)3OH12. 26H20) forms after the concrete is hardened (delayed ettringite formation) and cracks the concrete. Many of the concrete bridges and structures built in New Mexico in the past 20 years are in need of replacement due to deterioration. Many others constructed very early on in the century are still sound. By collecting and analyzing samples of both old and new concrete and good and bad concrete, we compared their differences on both a microscopic and macroscopic scale. Samples taken from concrete sidewalks, parking lots, drainage canals, spillways, and a railroad-trestle foundation have construction dates that range from 1923 to 1997. They were analyzed by electron microprobe and by petrographic microscopy. Cracks, air voids, and aggregate alteration were primary locations for investigation and analysis. Using the electron microprobe, ettringite was found in voids of most of the samples, both in good and bad concrete. This leads us to believe that ettringite formation is not causing distress in the concrete. There was one exception in which ettringite was found lining a crack. In this instance, ettringite may have the ability to further the cracking and cause distress. No alkali-silica gel was identified with the microprobe. Using the petrographic microscope in cross-polarized light, a light-brown material was observed that lined some of the air voids and cracks; however, exact mineralogic identifications were not made. Although many instances of chalcedony and other deleterious quartz phases were found, no clear evidence of ASR-gel deterioration was present in our samples using these methods. However, positive identification of the ASR gel was made on an in-place concrete near one of our sample sites and in several sample cores using a newly developed chemical test for the soluble potassium ions associated with the gel. The chemical used in this test is sodium cobaltinitrite, Na3Co(NO2)6.

Jan 1, 1999

By Valois R. Shea-Albin

Increasing pressure from State and Federal agencies to mitigate mining-induced subsidence damage to overlying structures has presented a unique problem to the coal industry in the western United States. Because sandstone escarpments are an environmental issue, millions of tons of coal reserves that underlie these escarpments risk being classified as unminable by regulatory agencies. At this time, the effect of subsidence on escarpments has not been well documented or characterized. The Bureau of Mines is using numerical modeling techniques to analyze escarpment response to longwall mining. Two- and three-dimensional finite element models have been constructed for a study area near Price, Utah, where longwall panels were mined near an escarpment. This status report includes preliminary results showing that the pattern of subsidence surrounding the escarpment can be simulated through numerical modeling. Models that include such structural details as joint and fracture patterns will better simulate subsidence patterns .and magnitude. By locating longwall panels strategically in relation to the escarpment, stability may be preserved throughout the mining process. Numerical modeling provides a method to analyze relatively quickly the effects of longwall panel location and resulting subsidence on escarpment stability. The goal is to provide a relatively accurate predictive tool for mine planning to determine if escarpment stability can be maintained while maximizing extraction of the coal reserves.

Jan 1, 1986

By Fred C. Schmednecht

For years, the strategy was to contain waste and in many applications, is still the recommended method. Recently, it has become acceptable to create filters below ground for the in-situ treatment of waste. Consequently, in lieu of the waste being contained, it is desirable that the waste flow through a pervious treatment zone. For instance, subterranean pervious walls comprised of iron sand are particularly useful in treating chlorinated solvents in contaminated groundwater. The iron acts as a corrective filter to treat the contaminated groundwater. How are these impervious and pervious walls being constructed? One effective means of constructing an impervious barrier is the vibrated beam method. This method, in brief, involves the use of a fabricated steel beam, a vibrator, a pile driving crane, and a mixing plant. This method results in a 4-6" wide wall with depths up to and exceeding 100'. Over one hundred slurry walls have been installed using this method in the United States. The need for the vibrated beam method continues to escalate due to its reduced health and safety considerations, high level of quality control, lack of excavation, narrow working area, and ability to achieve depths greater than 100'. A recent project was in Marinette, Wisconsin at the ANSUL facility. The project consisted of a 28,000 square foot slurry wall and was completed in January of 1999. Another effective means of creating an impervious barrier, where structural support from the barrier is needed, is the Waterloo® Barrier System. This system involves the use of a pile driving crane, Waterloo® steel sheet piles which are patented steel sheet piles due to their groutable interlocks, and a grout plant. This system results in a water-tight barrier due to the grouted interlocks and provides structural support. A project was completed at Beta Steel in Portage, IN for a retention pond to protect Lake Michigan. Due to the new concept of "filtering", there are few accepted construction techniques available. One effective field proven construction technique is the patent pending mandrel emplacement technique. This technique involves the use of a fabricated hollow steel mandrel with a shoe, a vibrator, a heavy duty crane, and a material feeder. This technique results in a pervious wall which may be comprised of pure iron sand or any other flowable media. Using this technique, the pervious wall may be constructed in varying widths to depths in excess of 100'. A successful installation occurred in October 1997 at Cape Canaveral Air Station in Florida.

Jan 1, 1999

By Wenbing Xie

At Renlou Coal Mine, Huaibei Mine Area, the track entry deformed significantly after longwall mining in an overlying multiple seams. The supporting characteristics of primary roof bolts and shotcrete with wire mesh are closely related to the movement of the mine?s surrounding strata. A case study of a track entry deformation was monitored during the longwall mining of a selected overlying panel. The measured data showed the unique entry deformation pattern during the longwall mining in the overlying seam. Underground extensometer measurement showed that entry stability was mainly affected by the periodic roof weighting of longwall mining in the overlying seam. The displacement of the deeper strata occurred a head of the immediate vicinity of the entry. Thereafter, deformation of the roof and floor strata was in the form of shearing of the shallower strata. Due to the use of heavy-duty roof bolting with wire-mesh, the roof-tofloor and rib-to-rib convergences were small, but the floor heave was large, greater than 80% of the roof-to-floor convergence. The measured displacement from extensometers varied with the position of the monitored cross-sections and depth into the roof. There were several deformation patterns, such as shearing movement, compression, and expansion, and the variations between compression and expansion. Strata compression at the entry surface was always accompanied with shearing movement at the deeper strata. During the longwall mining, the whole surrounding strata of the entry moved toward the opening. Underground practical experience indicated that prior to mining, the entry was supported very well in excellent conditions. After mining, however, it deformed greatly. The current entry support technology was not effectively control the severe deformation incurred in entries driven in soft strata due to the following reasons: (1) little is known about the entry deformation behavior of the strata surrounding the opening and (2) the degree of interactions between entry deformation and roof bolting with wire mesh is not well understood. Consequently, effective supporting systems cannot be properly selected to control its deformation and maintain a stable supported surrounding structure.

Jan 1, 2012

By R. H. Seraphim

"Western Mines Limited produces gold, silver, copper, lead and zinc from a number of Paleozoic volcanogenic deposits near Buttle Lake on Vancouver Island. The deposits were emplaced along a series of submarine linear volcanic ridges that extended for at least 6,000 metres in a northwesterly direction.Rock types mapped include: andesitic, dacitic and rhyolitic flow s and volcanic breccias; detrital breccias, tuffs and hematitic silts; black and green cherts; and a variety of dykes and sills, including quartz porphyry and diorite. Orebodies are associated invariably, and in places intimately, with quartzsericite schist and rhyolitic rocks. The ore is complex, varying in mineralogy and tenor both within each deposit and from one deposit to another.Recent studies have increased our knowledge of the structure and left no doubt that the orebodies were deposited both within the throats of the linear vents and on paleoslopes adjacent to these vents.IntroductionWestern Mines Limited operates an 850-tonne-per-day mine, located 85 km south of Campbell River, B.C. The mine is at approximately 400 metres elevation, near the south end of Buttle Lake on Vancouver Island (Fig . I). It has operated since early 1967 and produced 3,650,000 tonnes with an average grade of 1.9 g (0.06 oz) gold, 93 g (3.0 oz) silver, 1.6 per cent copper, 1.0 per cent lead and 7.5 per cent zinc per tonne by the end of 1978. Current reserves are 1,157,000 tonnes of 2.7 g (0.09 oz) gold, 117 g (3 .8 oz) silver , 1.2 per cent copper, 1.2 per cent lead and 8.0 percent zinc per tonne (December 31, 1978).Ore from one zone, known as Myra High-Grade, is mined and milled separately because of its grade. Ore milled prior to December 31,1978, plus reserves, 180,715 tonnes of6.6 g (0.21 oz) gold, 554.5 g (17 .7 oz) silver, 0 .8 per cent copper, 3.2 per cent lead and 10.6 per cent zinc are included in the figures listed in the preceding paragraphs."

Jan 1, 1980

By Rafael C. Castro, Geoffrey Hughes, Fredrick (Rick) Vincent, Philip H. Albert

Seven pairs of drop and ventilation shafts, between two and nine feet in diameter, will convey combined sewer flow to a 230-foot-deep, 26-foot diameter storage tunnel. This paper will present case histories for each site. Discussion will include functional requirements, program and site access constraints, structural design, geology, the variety of excavation and lining construction methods used, and lessons learned. Noteworthy observations include the importance of assuring competent ground sup-port at the soil-bedrock interface and of achieving tight verticality tolerance using both top-down and raise bore excavation methods.

Jan 1, 2007

By Stephen Mansfield

In metalliferous mining operations, subdrill is that portion of the blast hole that is drilled below the target grade elevation, and in most cases loaded with explosives. Its primary aim is to enable efficient excavation down to the target floor level. Subdrill is often described as being expensive and that excessive subdrill should be avoided, as it can result in damage to the subsequent floor, lead to difficult drilling conditions and higher vibration levels. As a result, many operations aim to apply the bare minimum amount of subdrill in order to excavate to the target floor. At a large open cut copper operation, challenging geological structure resulted in slabby and blocky fragmentation in the stemming region, resulting in poor crusher throughput due to bridging. To overcome the poor fragmentation in the top of the bench, longer than conventional subdrill was used to precondition the top third of the bench. The technique significantly improved the run of mine fragmentation and resulted in feed to the in-pit crushers that is more consistent, which produced less crusher downtime due to bridging. A new method of quantifying the energy in a blast has been created. Termed the linear powder factor, or energy factor, the calculation considers the energy contributed by the subdrill of the upper bench and its impact on the energy in the lower bench. The technique enables blast designs to be optimised to deliver finer fragmentation and more consistent blast outcomes. To support the layer of preconditioned rock at the top of the bench, an innovative new device was developed. The device is inserted into the drill collar immediately after drilling and remains in position throughout the subsequent steps of hole depth measurement, priming, loading and removed prior to stemming. The device not only supports the broken rock at the top of the bench, but also minimises the amount of drill cuttings that fall back into the hole. Furthermore, the device helps protect the hole from damage by external factors such as weather events, drill tracks, vehicle tyres and movement around the collar during measurement and loading of the blast hole.

By J. Drelich, J. Pletka

Lost foam casting patterns are foamed polystyrene shapes glued together into the shape of the part to be cast and are coated with a refractory material consisting of a mineral mixture and binders. Prior to casting, a significant number of the patterns are damaged and inevitably land-filled. In this study, a process is developed for the recovery of foamed polystyrene from the coating and glue contaminants. The process consists of shredding, impact comminution, size classification and density separation. It is successful in separating up to 97% of the contaminants, while recovering 95% of the polystyrene.

Jan 1, 2001

By Jochen Belz, Allan Henneker, Nod Clarke-Hackston

For the construction of tunnels and other underground structures, extraction of the exact amount of material is of paramount importance both economically and for engineering purposes. In the Sequential Support Method (NATM) immediate (sequential)and smooth support by means of shotcrete, steel arches, lattice girders and rockbolts, either singly or in combination are used; cutting of the precise (albeit sometimes of complex geometry) profile is an integral part of the method. In order to save unnecessary excavation and provide better information to the machine operator, VMT GmbH has developed a system to support precise excavation of the tunnel profile when using road headers or other partial face cutting machines. This paper outlines the principles of this system with examples from Australia, Ger-many, Sweden and Spain and will cite examples of typical savings achieved.

Jan 1, 2007

By C. D. Elifrits, N. B. Aughenbaugh

Introduction Federal and state laws enacted to regulate coal mining and the accompanying public concern about the adverse effects that mining might have on land use have focused much attention on the subsidence of the land surfaces over underground mines. Some questions asked are: • Will abandoned mines subside in the future even though they have exhibited no surface adjustment to date? • If so, when will subsidence take place? • Can a specific surface area be affected by subsidence more than once? • What surface form will the subsidence feature take? • Is there any way to predict when subsidence will occur and end? An attempt is made here to address these questions insofar as it is possible with available data and experience of evaluation of subcritical extraction conditions. Mining that results in subsidence features can be classified as supercritical, subcritical, and critical with respect to the minimum span lengths of the worked-out rooms (Fig. 1). A complete basin will not develop fully immediately over subcritical conditions because the span lengths of the entries are less than the critical dimension (Wardell, 1983). Passageways, entries, and room-and-pillar panels are all included in the subcritical category. Because of the short span lengths, subcritical mining conditions tend to be stable over the life of the mine unless adverse geologic conditions exist (Gray et al., 1974; Dunrud, 1976). Various roof control and support procedures are employed to maintain entry stability during mining. Little information exists concerning the time factor of subsidence over areas of subcritical extraction. Data that have been collected relate to longwall mines, whereby the cavity sizes are designed large enough to induce caving behind the working faces so that complete subsidence at the surface occurs within a short period of time. The UK's National Coal Board (1975) has reduced the enormous amount of data it has collected to empirical correlations and has published these correlations in its Subsidence Engineers Handbook. The handbook states that "None of the foregoing remarks applies to pillar and stall working," with respect to the section discussing the time factor of subsidence caused by longwall mining (National Coal Board, 1975, p. 40). To understand and evaluate how time relates to subsidence above room-and-pillar mines, one must first recognize how mine cavities deteriorate and fail. The propagation of failure to the surface must then be studied, and, finally, the failures that are manifest at the surface in the form of depressions accompanied by both compressional and tensional movements must be investigated. Failure of mine cavities Any cavity beneath the earth's surface represents a condition of nonequilibrium and tends to close with time. Failure of cavities in a subcritical mine can be classified as failure of the roof, failure of the floor, failure of the supports (pillars, cribs), and elastic rebound of the rock. One mode of failure may dominate, but generally combinations of the four will occur. Also, initial instability of geologic materials and structural features and in situ stress may be unknown factors that can contribute to cavity failure. Roof failure is the most obvious opening stability problem in most operating mines. The bridging capabilities of the roof rock are dependent on the rock's material strength, geologic discontinuities, and reaction to humidity changes in the air of the mine. This type of failure may vary in magnitude from gradual flaking to massive roof falls. Mine floor instability can be manifest in the form of a general heave over a broad area or of individual pillar punching. The weaker and thicker the immediate floor material, the more prone a mine is to experience floor problems. Water seeping into an area can soften the underclay, reduce its bearing capacity, and precipitate failure of support for the overburden.

Jan 8, 1986

By Yindong Yang

Despite the importance and usefulness of basicity in metallurgical slags, the optimum quantitative expression of it has remained elusive, partly due to the fact that the precise concept of basicity has not been properly clarified. The two basic approaches to the concept of basicity are the Lux-Flood, which perceives basicity in terms of the activity of the free oxide ion, a O2- , and the Lewis, which perceives basicity in terms of the ability to donate negative charge. The former has been almost universally adopted in the area of metallurgical slags, while the latter has been increasingly accepted in the field of glass chemistry. In this paper, some difficulties of the Lux-Flood approach are pointed out, including the need for indirect measures of a O2- , which have proliferated in recent years. Accordingly, it is suggested that the Lewis approach has a good deal to commend it, and that the quantification of it in terms of optical basicity is the best measure of basicity available, which should therefore be more widely applied in metallurgical slags than it currently is. The fact that there are intrinsic problems in evaluating the optical basicities for the transition metal oxides is acknowledged, and a new scale is recommended. The patterns of iso-optical basicity lines in ternary systems are shown to agree well with the pattern of iso-activity and iso-capacity lines under appropriate conditions. * Originally published in the Proceedings of MINPREX 2000, published by The AusIMM.

Jan 1, 2001

By P. A. Olubambi1

Representative samples of the hydrothermal vein deposits of the bulk complex sulphide ore deposit, 10 km south of Ishiagu, in Ebonyin State, South Eastern part of Nigeria were collected from two small scale mining companies. The samples were mixed and successively crushed in a jaw crusher and cone crusher, and ground in a rod mill. Characterization was carried out with SEM, EDX, XRD, XRF and ICP-OES. Mineralogical analysis revealed the presence of sphalerite, galena, siderite, pyrite, quartz and chalcopyrite. X-ray Diffractometry showed that sphalerite mineral in the ore occurs as sphalerite ferrous with varied percentage of Zn and Fe within the various sizes while chalcopyrite occurs as a chalcopyrite group mineral with chemical formula Cu2MnSnS4. Results of the elemental analysis showed variations in elemental composition within the different sizes.

Jan 1, 2006

Variations in product distribution in the carbon-sulphur dioxide system due to variations in reaction temperature, sulphur dioxide concentration in the feed gas, and gassolid contact time were studied in detail for a brown coal char. The results were compared with those for two wood chars, a coke prepared from Liddell coal and two cokes prepared from Ac1and coal. Conditions were chosen such that gas-solid diffusion rates did not hinder chemical attack of the carbon.With brown coal char under suitable conditions, the selectivity of sulphur in the sulphur dioxide fed, to either elemental sulphur or carbon disulphide, was in excess of 90 per cent. The wood chars gave very similar product distributions Ito brown coal char. However, the cokes from Ac1and and Liddell coals were respectively approximately three and seven times less reactive than the brown coal char.The approximate carbon holdup required to just achieve total conversion of sulphur dioxide, and thereby achieve high selectivity to elemental sulphur, is given as a function of reaction temperature.

Jan 1, 1974

By Scott Ellenbecker

The formation in Newmont Mining?s Phoenix Mine near Battle Mountain, NV contains high levels of abrasive quartzite as well as gold, copper and silver. Newmont started mining operations at Phoenix (formerly Battle Mountain Gold) three years ago and the planners knew they were working with a challenging geological formation. But as it turned out, it was more challenging than anticipated. Mine manager Mark Evatz said, ?Anything that touches Phoenix rock wears fast. The rock fights back here.? To contend with the hard conditions, Newmont uses Atlas Copco?s Pit Viper 271 (PV-271) blasthole drill. Because of the hardness of the rock, drilling at Phoenix requires hammer drilling and the mine uses Atlas Copco TD65 hammers with 171 mm (6.75 in.) bits. The mine?s PV-271?s are outfitted with a single 41 m3/min (1450 cfm), 2.4 MPa (350 psi), oil-flooded air compressor. Phoenix has six Atlas Copco PV-271 drill rigs plus an Atlas Copco DML and a DM45 midrange blasthole rig. The mine?s goal is to keep 3.6 Mt (4 million st) of muck in inventory to stay ahead of the shovels and support needed operational flexibility (ore control related). Drilling efficiency has been a continuous point of improvement since operations began at the mine. The single-pass depth capability of 16.5 m (55 ft) on the PV-271 helped with that. Originally, the plans called for 6-m (20-ft) bench heights, supported by 7-m (23-ft) drill depths, and time spent moving from hole to hole was eating up productivity. Drilling on that plan resulted in drilling an average of 14 m/h (47 ft/hour). When depths were changed to 13-m (44-ft) drill depth, supporting blasting of 12-m (40-ft) benches, they were able to use the single pass capacity of the PV-271. Performance increased to more than 18 m/h (60-ft/hour) an hour. Although the drill depth change largely supported the improvement, other aspects of continuous improvement associated with improved knowledge of the Pit Viper drills helped as well.

Jan 1, 2009

By Geir Martin Haarberg

Modern electrolysis technologies can provide possibilities for developing sustainable processes in terms of energy and environment. Laboratory experiments were carried out to study electrodeposition of iron from molten salts and aqueous solutions using an inert oxygen evolving anode to eliminate the emissions of CO2. The possibilities of molten salt electrorefining of metallurgical grade silicon to produce solar grade silicon were also investigated. Electrochemical techniques were used to study the electrochemical behaviour of dissolved iron, silicon, and titanium species. Bulk electrolysis was carried out to deposit pure iron, silicon, and titanium. The quality of the deposits was studied by SEM/EDS and XRD analyses. Calculations based on laboratory studies indicate that great improvements in terms of reduced energy consum

Jan 1, 2010

By P. C. Fletcher, E. Kaya

The Bond grindability testing procedure has been standardized to measure the same grindability values, i.e. Bond work index (BWi), for the same ore when tests are performed in different laboratories or by different operators. This is accomplished by the standardization of mill dimensions, tumbling speed, grinding ball charge weight and distribution, sample ore charge weight in the mill and operating practice. The results of this investigation reveal that the Bond work index grindability values may differ substantially with different standard Bond ball mills. This paper will review the results.

Jan 1, 2002