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By G Sparrow

The Murray Basin is being heralded as the next major mineral sands province in Australia. Already exploration programs have delineated extensive commercial deposits and several companies are progressing with plans to produce zircon, rutile and ilmenite in the Basin. As these deposits are developed consideration will need to be given to several key issues of the Murray Darling Basin; the availability of fresh water and management of salinity in the area being two of them. In this paper ideas being developed in CSIRO that link the processing of mineral sands with the salinity problem in the Basin are presented. The proposal presented here is to process saline water to produce industrial minerals with large volume applications and to produce value-added products from the mineral sands in the Basin using reagents produced from the saline waters. Processes to produce titania pigment and zirconia consume chlorine, caustic soda, soda ash and hydrochloric acid, all derivatives of salt (sodium chloride). There may be a good economic incentive if these processing plants were located in the close vicinity of each other.

Jan 1, 2001

By Ira Sohn

This article revisits global projections made in 1981of eight metallic and fertilizer minerals for the year 2000. The objectives here are to quantify the differences between the projected and observed levels of consumption for the year 2000 for eight of the 26 nonfuel minerals covered in the earlier study. An attempt is then made to attribute these (often) large differences to the major determinants of minerals demand — income, technological, regulatory and other policy changes, and changes in the recycling rates of the metallic minerals. The eight minerals covered are aluminum, copper, iron, mercury, nickel, phosphate rock, potash and tin. This summary article presents the actual population, gross domestic product (GDP) and per capita GDP changes from 1970 to 2000, compared with the projected rates for these important determinants of mineral use, along with the observed growth rates of minerals consumption for the eight nonfuel minerals included in this study. When the projections are compared with the observed global consumption levels for the year 2000, the differences range from +43 percent for nickel to +229 percent for potash.

Jan 1, 2005

By C. E. McManus

MANY mechanical advances have been made on mining equipment during the year 1951. There have been a number of trends established and many modifications made on open-pit equipment to increase the efficiency and availability of all the machines necessary in the moving of overburden and iron ore. Some years ago, the trend toward larger shovels for the loading of off-highway trucks began, but in the last year, it has become general practice to use the 5 to 7 ¼ -yd quarry-type shovels in the loading of haulage units. For years these larger shovels were used in the locomotive haulage pits. As the truck capacities increased from 15 to 20 to 30 tons, the need for larger loading units became apparent. Today in most mines, large shovels are in evidence and a few 8-yd shovels will be delivered this year for loading off-highway trucks. Torque Converter-Shovel The Diesel-driven shovel with its friction bands has been modernized with the torque converter. There have been about ten shovels remodeled to take a torque converter in the drive system. The large high-torque, low-speed Diesel engine was removed and replaced by a high-horsepower, high-speed, automotive-type engine. This engine was connected directly to the torque converter. The torque converter was connected to the shovel through the standard original sprocket and chain. Dual governors controlled engine performance. One governor controlled the high idle of the engine; the other governor, which is connected through a flexible shaft to the output shaft of the converter, controlled the loading of the engine. With this dual governor hook-up, the engine anticipates load conditions and is operating at high idle and full throttle before the shovel load is transmitted back through the converter to the flywheel. It has been found that with this automotive-type engine and converter, the shovel capacity has been increased about 20 pct. Also, the wear on the friction bands, breakage of hoist cables, and other mechanical breakages has been reduced materially. Alloy-Steel in Shovels The shovel equipment manufacturers have been experimenting with low-temperature-strength, high-alloy steels to combat the excessive breakage that occurs in extremely cold weather. High-nickel alloy steel has been used in critical areas that are affected by low temperatures, the most notable being dipper sticks. Most shovels ordered today are equipped with some of this special, alloy steel. More and more manganese alloy is being used for replacement parts such as shovel pads, idlers, drive sprockets, etc. Although the initial cost of these parts is considerably higher than the standard replacement items, the life of these manganese parts is considerably longer and well worth the added expenditure. Dipper-teeth repair is still a problem. Most companies use the small replaceable inserted tooth. It has become common practice among some of the companies to "job out" their dipper-tooth repairs to outside welding companies. This necessitates an additional inventory of teeth, but it does guarantee an adequate supply of replacement teeth at all times. These contractors have set up their shops on a production basis and can do an acceptable job at a high rate of speed. Thermite welding has been used in retipping teeth. To date, the process cannot be called successful but with improvements the time required to repoint the dipper teeth will be decreased considerably. The submerged arc process has been tried in the replacement of these dipper points, but like thermite welding has not proven successful. Here again, if a method can be developed to use submerged arc, the job of teeth repair will be made much easier. New model shovels in 6 ½ and 8 cu yd sizes fea-

Jan 1, 1952

By F. Z. Suo

Baoahan Iron and Steel Complex is situated at lower beaches of the Yangtze River. The subsoils 50~70 M below the surface is a deposite of Yangtze River delta, consisting mainly of weak silty clay and loam, with low soil bearing capacity. Consequently, to build on such a weak soil a grant iron and steel integrated works weak soil improvement at the Complex, pile foundation is the effective type. It is estimated that at the first stage of Baoshan project 60,000 piles have been driven, of which 60% are steel pipe piles and 40% reinforced concrete piles. To provide reliable basis for pile foundation design, on-site loading tests were carried out for long reinforced concrete piles 27,45 60 M in length ,with strain gauges on the chief reinforcement of pile shaft and strain rod on pile tip. Based on loading tests, the paper discusses and analyses some issues, including determination of load transfer mechanism distribution of frictional resistance. Tests show that as far as long friction piles in soft clay are concerned, regardless of the properties of pile tip's bearing stratum, loads are mainly carried by shaft frictional resistance which it is effective to determine pile capacity in terms of P ~ S relationship.

Jan 1, 2010

By SungWon Park

The efficiency of the current design methods for computing pile resistances is evaluated using field load-settlement tests results. Twelve load-settlement test data for drilled shafts and bored piles were obtained from the literature. These load-test data were fitted using the ?t-z? method. Subsequently, the ultimate resistances were evaluated based upon the failure criteria from following methods: (1) the Davisson?s approach and (2) settlement corresponding to 5% or 10% shaft diameter approach. The ultimate resistances for these drilled shafts and bored piles were also predicted using methods based on the design code from North America (United States, Canada), Europe, and Asia (Japan). The pile resistances determined from field load-settlement tests were compared with those calculated using the design codes. The comparisons show that most design codes predict a conservative resistance for drilled shafts and bored piles. However, in the case of drilled shafts, we find that some of the design codes can over-predict the resistance and, therefore, should be applied cautiously. This research also shows that ?t-z? method can be successfully used to predict the ultimate resistance and the load transfer mechanism for a single pile.

Jan 1, 2009

A well known rock mass classification system has been altered slightly to address the issues found under remnant mining conditions. By detail study of the expected fracture patterns and local geology, the rock mass is classified to indicate the condition of the hanging wall prior to mining. The risk level of each mining step is evaluated by calculating input parameters for computer simulations from the actual rock mass condition. Seismic activity is catered for by the understanding that large event rates and large magnitude events reduce the quality of the local rock mass and that the rock mass stiffness should be adapted accordingly. A case study is presented to test parts of the protocol. Un système connu de classification des masses rocheuses a été légèrement modifié pour faire face aux questions posées par les conditions d’extraction de débris. Une étude détaillée des diagrammes de fragmentation et de la géologie locale permet de classer la masse rocheuse pour indiquer la condition du toit avant l’extraction. Le niveau de risque de chaque étape minière est évalué en calculant les paramètres d’entrée pour simulation par ordinateur à partir de la condition réelle de la masse rocheuse. L’activité sismique est prise en compte avec la réalisation que les taux de larges évènements et les évènements de large magnitude réduisent la qualité de la masse rocheuse locale et que la raideur de la masse rocheuse doit donc être adaptée. Une étude de cas est présentée pour tester des sections du protocole. Ein sehr bekanntes Gesteinsmassenklassifikationssystem wurde abgeändert um die Probleme zu behandeln die unter Restabbaukonditionen angetroffen werden. Durch detaillierstes Studium der der zu erwartenden Bruchmuster und der lokalen geologischen Verhältnisse wird die Gesteinsmasse in Hinblick auf die Konditionen der Flözoberseite klassifiziert. Das Risikoniveau für jeden Abbauschritt wird durch die Eingabeparameter aktuellen Gesteinsmassenkondition für die Computersimulation evaluiert. Für die Seismische Aktivitäten wird Sorge getragen durch das Verständnis, daß große Ereignisraten und Ereignisse hoher Größenklassen die Qualität der lokalen Gesteinsmasse reduzieren und daß die Gesteinsmassensteifheit entsprechend adaptiert werden sollte. Eine Fallstudie um Teile des Protokolls zu testen wird präsentiert.

Jan 1, 2003

By Rodolfo Espinosa Gómez

"Industrias Peñoles, S.A. de C.V. – Mining Division, has initiated in the last ten years, six Mining Operations (Bismark, Tizapa, Ciénega, La Herradura, Rey de Plata, and Francisco I. Madero) and it has expanded several of their existing Operations (Sabinas, Fresnillo, Tizapa, Ciénega) one or more times.This work aims to share the experiences learned on this growing process. Some of these lessons are: 1) Project leaders must have a leadership that fosters good communication and team work; and this leadership style must come from top management. 2) A good communication must exist between the personnel from Engineering, Construction, and Operation. Also, this good communication must come from top management. 3) Starting the project with a solid Engineering Study. 4) Do not misunderstand cost with cost/benefit; always look at the cost/benefit. 5) Selecting good Contractors and good Suppliers. 6) Good training before the project commissioning is essential to reduce the learning curve period, this is even more important in areas where local people do not have any background in mining activities. 7) Recognizing that any project has a learning curve and it must be reflected on the production budget. 8) Avoid an over optimistic Mine preparation time schedule.BACKGROUNDIndustrias Peñoles S.A. de C.V.The mission of Industrias Peñoles, S.A. de C.V. (Peñoles) is to add value to non-renewable natural resources in a sustainable manner. Peñoles seeks to build long-term shareholder value; provide their customers with the highest quality products and services; maintain productive longterm relationship with their suppliers; develop and promote the capabilities of their personnel; foster mutually beneficial relationship with the communities in which it operates, and preserve the environment.Peñoles was established on 1887. It is a Mining Group with integrated Mining, Smelting and Refining operations of non-ferrous metals, and also produces inorganic chemistry materials. Peñoles is the main World producer of refined silver, metal bismuth, and sodium sulphate; Latin American leader in the production of refined gold, lead, and zinc.The Mining Group is made-up of nine mining operations producing concentrates with high gold, silver, lead, zinc, and copper contents. It produced in 2002, 365,900 ounces of gold; 52.7 million ounces of silver; 86,820 tonnes of lead; 266,000 tonnes of zinc, 11,840 tonnes of copper; with a total values of 3,780.6 million of Mexican pesos (~ $ 378.0 million U.S. Dollars)."

Jan 1, 2004

By Guo Junfeng

The strength of coal mass saturated with gas is an essential parameter in studying the mechanism of gas and coal outburst, and its prediction method. Up to now, there has not been a method for determining the strength of coal mass saturated with gas. This paper describes a new method whereby the strength of in-situ coal mass can be determined and stored continuously and automatically. The simulation results obtained in the laboratory indicate that the new method allows a fast, reliable, inexpensive and convenient determination of the strength of coal mass.

Jan 1, 1992

By Alan Mayton, Bertrand Valero, Farid Amirouche

Handling of heavy vehicles such as tractors, trucks and buses require a large roll stiffness which causes large high accelerations at the seat level during impacts. To provide comfort and minimize the energy transfer from the chassis and the seat a pneumatic active seat suspension is proposed. An active seat suspension design and control algorithm under development at the University of Illinois at Chicago, UIC, is being developed and tested. Preliminary results are presented in this paper. The design of a passive suspension typically consists of optimizing the value of two parameters: the stiffness and the damping of the suspension. The general dynamic performance of the suspension is limited to the conditions under which these parameters were obtained. A change in the input conditions might lead to poor suspension and an amplification of the vibration transmitted to the body. The focus of this paper is a robust, semi-active suspension system with a variable controlled damping and using the body response an index measure to minimize the acceleration at the interface of the seat and operator. A summary of existing suspensions, such as MR and ER fluids, and spring loaded and dual valve shock absorbent will be discussed to highlight the need of a semi-active pneumatic suspension system design. Methods A model of the proposed suspension was developed in MATLB (Simulink) and different control strategies for the valve position in relation to the cylinder pressure tested. The effects of stiffening and softening resulting from pressure changes in the cylinder were examined. The vertical accelerations of the seat was computed for different control strategies and configurations of the suspension and compared to the response of a passive seat suspension. A lump -mass model was created to represent the human body including the head, the upper, middle and lower torso as well as the legs. The connective forces between body segments were modeled through modal analysis techniques from previous experiments at the Vehicle Technology Laboratory. ISO standards and absorbed power were used to evaluate the different configuration of the seat suspension system in relation to the dynamic response of the operator. Results Initial results of the semi-active suspension system show a significant reduction in the RMS value of the acceleration of the seat. A reduction of the total absorbed power by the operator is expected to provide an insight into the control strategies adapted in the active suspension.

Jan 6, 2006

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Jan 1, 1938

By Colin Hardie, Erik Bartsch, Guy Comeau

"The Xstrata Nickel Raglan Concentrator, located at the northern limit of Quebec’s Nunavik region has been in operation since 1997. Originally designed to process 800,000 tonnes per year of high grade nickel ore, plant capacity is currently approaching 1,200,000 tonnes per year due to an Optimization Project (FAG to SAG conversion) in 2005 and many recent processimprovements.In 2006, the Raglan Metallurgical Group with assistance from the Xstrata Process Support group decided to make SAG control one of its priorities in order to further increase throughput and improve stability. The original primary mill control logic delivered by the Optimisation Project in 2005 consisted of a simple PID loop controlling the mill charge (bearing pressure) through feed rate changes. Due to the multivariable, non-linear and disturbance dominated nature of the SAG circuit it was quickly found that this traditional PID control strategy was not able to adequately control the mill; resulting in poor stability, frequent operator interventions and less than optimum performance.This paper describes the successful integration of advanced field systems such as mill feed image analysis (Wipfrag) and crusher gap controller (ASRi), into a multi-variable fuzzy logic SAG mill controller. The process of how a strategy for control was developed and implemented directly in the existing control system (exploiting standard system capabilities) is discussed. It is also shown how this approach has provided mill automation which is simple, robust (despite erratic feed characteristics), and delivers both an increase in throughput and a reduction of variability.INTRODUCTIONOriginally commissioned as a Fully Autogenous Grinding (FAG) circuit in 1997, preparations to convert the Katinniq Concentrator Mill to SAG had in fact commenced as early as 1999, but were halted owing to alternative process improvements which achieved up to 1Mtpa as early as 2000. Up until this time, plant process controls had remained more or less static; modifications having been limited to those required by new equipment. Primary mill process controls and related measurements were at this stage limited to:"

Jan 1, 2008

By A. Mayton, W. Porter, A. O’Brien

In 2004, management at Unimin’s Gleason, TN operation began implementing ergonomic interventions specifically targeted to reduce risk of musculoskeletal injuries (MSIs). Together with corporate and site management, Unimin identified work site hazards and began to modify work practices/equipment. Some interventions were relatively simple and were implemented immediately. Others, like improvements to a mobile shredder, were more complex but were eventually resolved through a participatory approach with employees, management, manufacturers and NIOSH. This paper discusses ergonomic interventions that were successfully implemented using a bottom-up approach to reducing the risk of injury.

Jan 1, 2007

By Mohammad Noaparast, Babak Fotoohi

"Due to certain advantages in (semi-)Autogenous-Ball mill circuits in most of the high-throughput ore grinding units of mineral processing plants, much attention is paid to optimize the mill performance. Despite the maturity of the grinding mill mechanical design, there had been made less attention to the efficiency of the grinding media in the past. In this research, the possibility of establishing a relationship between liner/lifter wear rate and variations in the composition of the iron ore (from Chadormalu mine) is investigated.Measurements and determination of liner/lifter wear rates and patterns concluded in recognition of critical liner segments exposed to much abrasion during the ore grinding. After metallurgical analysis of liner materials and correlation of wear rate with the ore composition, the homogeneity in the metallurgical microstructure of the alloyed steel (such as the uniform distribution and amounts of the constituent phases) was determined as the most influential factor in the response of the liner/lifter to the variations in the ore composition. Magnetite with greater abrasion index than hematite, in finer particles, is responsible for additional abrasion of liners; hematite with greater work index exists in the mill with larger particle sizes, thus it could produce wear on liner parts with less tolerance to impact as is the situation for martensitic steels.INTRODUCTIONThe mineralization in Chadormalu plutonic iron ore deposit is consisted of mostly magnetite, hematite, martite, apatite, quartz and carbonates. The average composition of the ore is presented in Table 1. In the processing circuit, the gyratory crushed ore reduced to 30 cm would finally be the feed to three similar 32’ semi-autogenous mills in parallel processing lines. The pulp in the mill would have the characteristics mentioned in Table 2. The quality of the mill output has its direct effect on the downstream processes either physically or chemically (e.g. in cycloning or flotation respectively). In order to take advantage of optimum performance for these circuits, a close control of the ore grinding conditions is necessary; because any shortages in throughput, liner/lifter damage or changes in ore composition could bring the unexpected casualties. In this work, it has been attempted to find (possibly) a reasonable relationship between variations in ore characteristics together with liner quality and the amount of wear rate in different liner/lifter segments of a semi-autigenous mill. Liner/lifter segments are supplied by three different domestic steel making companies. The alloy structure of the liners/lifters is made up of pearlitic chromoly steel."

Jan 1, 2005

By R. C. Neavel

One of the most important requirements to be met by any coal producer is delivery of size consists tailored to specific applications. Generally these specifications include a minimum as well as a maximum size limit. The customers of a major Indiana coal producer noticed that some shipments of sized coal contained a large proportion of undersize pieces. Also, in these shipments, the pieces which remained within the specified limits were cracked and, when handled, crumbled readily. The producer, certain that these shipments had been properly sized at the tipple, suspected that degradation had occurred in transit. The Indiana Geological Survey was requested to examine the coal from one of these shipments to attempt to determine the cause of breakage. Two basic facts about coal and coal seams led to the employment of petrographic techniques in this investigation. First, all coal seams consist of accumulations of diverse organic and inorganic constituents; and second, most coal breakage, either desirable or undesirable, can be attributed to the inherent weakness of some of these constituents or to poor adhesion between certain constituents. Analyses of degraded coal Sampling: Samples were secured from 2 stock piles of 2-by 4-inch coal in a dealer's yard. The coal in both piles had received the same treatment from mining to storage, although it had been mined and shipped on two different days. The size consist of one pile, however, appeared smaller than that of the other. The sample from the degraded pile is referred to as the slack sample, and the other is called the unslack sample. Size analyses: In order to determine the actual size consist, the samples were screened, with a minimum of rough handling, on square 2-inch, 1-inch, 1/2-inch, and 12-mesh screens. It is assumed that 100 percent of the 2-by 4-inch coal is retained on a 2-inch round screen at the tipple. Analyses of several loads at the tipple indicate that approximately 26 percent of the 2- by 4-inch coal, 100 percent of which was assumed held on a 2-inch round screen, passed through a 2-inch square screen. Twenty-six percent may be taken as the normal difference between round and square screens. Results of the analyses of stockpile coal are shown in Table 1. Cumulative percent versus size are plotted on a Rosin-Rammler chart as Figure 1. Both samples approximately follow normal size distribution; this indicates that breakage is not size preferential and also that the samples are representative of the stockpiles. Although both samples exhibit the same general size distribution, the median size of the slack sample is considerably smaller than that of the unslack sample. Fifty-five percent of the unslack sample was undersize (29 percent greater than the normal 26 percent difference), and 83 percent of the slack sample was undersize (57 percent greater than the normal 26 percent difference). Both piles contained a greater percentage than normal of undersize coal; this indicates that they were both affected by degradation, but to a different degree. Bedding-plane analyses: Coal, because of its laminated nature, will break preferentially along bedding planes, especially where adjacent constituents are poorly cemented to each other. Subsequent breakage perpendicular to the

Jan 1, 1961

By A. Noble

Traditional simulations of mineral processing circuits are solved by straightforward numerical techniques which require iteration to accommodate recirculating loads. Depending on the complexity of the simulated circuit, this solution technique can be inexact, computationally intensive, and potentially unstable. In this communication, an alternate calculation approach is presented, wherein an exact analytical solution is determined as a function of the individual units? separation probabilities. All the stream data, including recirculating loads, may be solved simultaneously, negating the need for iteration. Furthermore, with an analytical solution available, circuit analysis may then be utilized to diagnose the relative separation potential of the circuit. By integrating these tools, the authors have developed a software package for evaluating circuit configurations. This paper presents the theory, development, and limitations of the software?s methodology along with industrial examples which highlight the tool?s applicability to industrial circuits.

Jan 1, 2012

By Mario E. Rossi

Las simulaciones condicionales geoestadísticas se utilizaron como herramientas de control de leyes en operaciones diarias que evalúan la incertidumbre y el riesgo de las reservas mineras en estudios de factibilidad, así como el potencial de mineralización en ciertos ambientes geológicos. Otras aplicaciones incluyen evaluación de recursos y reservas recuperables (dilución), clasificación de recursos y reservas, y optimización de espaciamiento de sondajes. En ese sentido, el presente trabajo señala los aspectos de los esquemas de clasificación de recursos y reservas utilizados en la industria, el cual está basado en el modelo de incertidumbre que las simulaciones condicionales proveen. Asimismo, se analiza el riesgo que este modelo de incertidumbre implica para sub-regiones (unidades) de extracción del yacimiento, como las definidas por fases de extracción mineras o períodos de tiempo.

Jul 17, 2000

By R. M. Owens, J. F. Lupo

The Shirley Basin Uranium mine, located in southeastern Wyoming, USA, was an open pit mining operation consisting of a series of several open pit mines excavated into poorly consolidated sandstones, siltstones, and claystones. Since the initial open pits were developed in 1969, slope failures have plagued the mine and mining operations. These slope failures have persisted into the current mine reclamation period. When the mine was first developed, the open pit slopes were designed to range between 45 to 55 degrees. Numerous slope failures during mine development required the pit slopes to be redesigned with slopes as shallow as 26 degrees. At present, movements are occurring within the open pits on reclaimed slopes that are shallow as 12 degrees. Several detailed slope studies were conducted at the mine in the early 1970s. These studies, combined with more recent geotechnical investigations, provide a unique detailed history of pit slope failures on shallow slopes. This paper presents an evaluation of the slope failures at the Shirley Basin mine, highlighting important mechanisms causing slope failures on very shallow slopes. The evaluation demonstrates important key parameters for shallow slope design.

Jan 1, 2001

At the inception of the gold-mining industry at Kalgoorlie the small supply of firewood required for steaming purposes was naturally all drawn from the limited local areas, which promised soon to become denuded. With the advent of the railway toKalgoorlie came the ever increasing machinery and steam power, and the accompanying demand for firewood so increased that the fuel contractors began their operations, by following the timber belts along the Yilgarn railway line, and graduallygetting further westward, until at present we find them as far as Woolgangie, 63 miles from Kalgoorlie, and with the regular railway rates, I0. per ton per mile, this maybe considered the limit of payable timber at current rates. Although in the early days the reserve of timber along the railway line must have appeared as incalculable and inexhaustible as that of coal did in Europe a couple of centurys ago, the day is now near us when even this source will fail to meet the demands made upon it, for, although a good two years' supply is available or the areas under the axe, yet it is time to look ahead and find from whence the future supplies are to be drawn. Along the railways we find the zone of felling operations limited for want ofcommunication, and only such portions of the forests as are within six or seven miles of the railway come under the axe at present while virgin forests to the rear remain practically unexploited. It is only in the course of the past sixteen months that the firewood industry has developed...

Jan 1, 1901

Mechanism of Modified Sodium Silicate on Fluorite Ore Flotation

Sep 13, 2010

In 2006, a total of 4,573 stone mining operations reported employment to the Mine Safety and Health Administration (MSHA).1 Stone mines comprised 30.7% of all mining operations. ? Mines producing the primary commodity of limestone (crushed and broken) comprised the largest number of operations (n=2,042; 44.7%). ? Stone mining operations were located in all states and territories except Delaware and North Dakota. ? Pennsylvania had the most stone mines (n=368; 8.0%), followed by Texas (n=342; 7.5%).

Jan 1, 2008