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By H. W. Wevers

This paper is the result of an intensive literature search and practical study of the problems experienced by a mining company with the frame cracking of their large-tonnage haulage trucks. It explains the advantages of particular HSLA steels for applications in the welded structures of such equipment. Examples of existing welds in truck frames are analyzed. Modern fatigue models and linear elastic fracture mechanics techniques are explained.

Jan 1, 1978

By David M. Rubio

The Ortiz Mine is an open pit-heap leach gold operation in central New Mexico processing about 3,100 tonnes (3,400 short tons) per day. It is the initial mining property in the United States developed by Gold Fields Mining Corporation, a subsidiary of Consolidated Gold Fields, PLC. This paper discusses the evolution of the present mining and ore control procedures as adaptions to the characteristics of both the rock being mined and the orebody, and with respect to the fact that mining is done by a contractor.

Jan 1, 1984

By Alan A. Bergeron, J. L. Michels, R. L. Collins

Advanced communication and monitoring systems were developed and demonstrated in three underground mines representing different mining techniques, geographical areas, and material mined. The first mine was a large coal mine in western Pennsylvania that used room and pillar techniques and continuous mining methods. The system developed for this mine provided private telephone channels, environmental monitoring, and control of underground equipment, all on a single coaxial cable, with all system operations under the direction of a minicomputer. Many advanced features were incorporated into the system, such as paging of roving personnel, two-way section wireless, through-the-earth emergency communication, and redundant signal paths. Television was multiplexed into the system for underground equipment surveillance. A hoist radio system completed the complement of equipment at the mine. The second mine was a magnetite ore mine in eastern Pennsylvania that used block caving mining techniques. A radio system was developed that provided two-way communications between trackless vehicles and roving personnel. A unique system of uhf/vhf repeaters combined with a flleaky-feeder" transmission line offered operational and emergency features not previously found in mine communication systems. Evacuation alarming, personnel paging, fan-hole drill operator communications, and maintenance and safety vehicle dispatch were provided. The system required no dispatcher and operated during power failure. A hoist communications/shaft inspection system completed the installation. The third mine was a deep silver mine in the Cour d’Alene district of Idaho. The system developed for this mine utilizes a single wire pair to provide up to 14 voice channels. A unique combination of PBX, telephone carrier system, and intercoms offered private conversations, selective signaling, and emergency backup communications. Two hoist communication systems were installed to provide a voice link and in-cage belling signal between hoistman and cage.

Jan 11, 1981

By M. Hamamoto, M. Furuta, S. Tanaka

The Tamano smelter and refinery has expanded its production from 228kt/y to 260kt/y since 2006. It was not a big jump, but efficient and economical improvements were executed. These were not only de-bottlenecking and modernization of the smelting plant, including the acid plant, but also additional processes were commissioned, e.g. slag cleaning furnace and steam dryer. On the other hand, a conversion to permanent cathode process in the #2 tank house made the biggest impact on production efficiency for the refinery plant. In order to overcome the drastic change of copper business, although each scale is not so big, continuous improvements are very important to survive. This paper mainly describes the recent improvements of the smelting plant.

Jan 1, 2007

By A Hughes, J Agius, T Ferguson, A Parbhakar-Fox, D Lester, L M. Jackson

Management of historic tailings is a major challenge facing the mining industry and its regulators. However, through improved mineralogical and chemical characterisation of such materials the opportunity to develop better rehabilitation strategies arises. Microanalytical techniques including microscopy, mineral liberation analysis and laser ablation inductively coupled plasma mass spectrometry (ICPMS) allow for improved tailings characterisation – but the challenge posed by these techniques is how to use them effectively. Additionally, data sets collected by such techniques must be properly integrated, only then can they assist in the identification of the most appropriate rehabilitation strategies. A study conducted at the Old Tailings Dam (OTD) located at the Savage River Mine, Tasmania allowed for the integrated use of several microanalytical techniques to help evaluate the benefits of a shallow water cover as a potential rehabilitation strategy. Samples (n = 144) from 14 trenches and 11 boring cores (2 m maximum depth) were collected across the OTD. These were subjected to routine acid-base accounting, with a subset subjected to detailed mineralogy using a modified sulfide alteration index (SAI), X-ray diffractometry and mineral liberation analysis (MLA). In addition, representative samples (n = 6) from across the OTD were subjected to laser-ablation ICPMS to characterise the pyrite chemistry. Our results showed that tailings in the northern area submerged under a natural water cover were relatively unoxidised from approximately 1 m depth, with SAI values of 1 to 2. Tailings from the subaerial southern portion were extensively oxidised to approximately 35 cm depth (SAI = maximum 5.8), with fresher materials observed underneath (SAI = 5 to 5.8). Pyrite from across the OTD is enriched in Co, Cu and Ni. Through the integrated application of microanalytical tools, we determined that establishing a water cover of at least 1.5 m depth across the OTD is a suitable rehabilitation option for this historic site. However, consideration for the reprocessing of these tailings to extract Co should be further investigated.CITATION:Jackson, L M, Parbhakar-Fox, A, Hughes, A, Agius, J, Ferguson, T and Lester, D, 2015. Microanalytical evaluations of the savage river old tailings dam, north-?west Tasmania, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 111–124 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By Kenneth R. Hancock

Iron oxides are unique in that they are the only significant colored mineral found in a natural state suitable for use as a pigment after being pulverized to pigmentary size. The current world production of iron oxide pigments is estimated by the author to be between 499 and 590 kt (550,000 and 650,000 st) based on 1979 data. The fact that highly colored natural deposits of iron ore are found throughout the world accounts for its use in prehistoric man's artistic cave paintings. These early artists did not realize that they had established man's first paint test fence which now has some 20,000 years of exposure. In addition to abundance, constituting about 7 % of the earth's crust, iron oxides have the advantages of low cost, permanency, and are not toxic. Through the centuries, succeeding civilizations have utilized iron oxides as a major source for decoration and protection when coloring was desired. In the last century the chemical industry has improved on nature by developing a complete range of synthetic iron oxide pigments which surpass the pigments produced from natural iron ores in uniformity, color quality, and chemical purity. In the United States alone, the combined production of natural and synthetic iron oxides produced sales of over $28,000,000 in 1970 (Stipp, 1970) and increasing to $97 million by 1980 (Spinrad, 1980). Nomenclature With the increasing importance of the synthetic iron oxides it is necessary to make a distinction between the natural or mineral pigments and the synthetic pigments. Natural pigments are those products which are derived from selected ores and should not be confused with iron ores mined for steel production. Iron ores that are mined for steel must be capable of being mined and reduced to iron on a commercial basis. These ores are selected on the basis of iron content and processing economics. It is therefore unusual when iron ores for steel production are suitable for use as mineral pigments. Natural pigment ore sources are selected for their special physical-chemical properties and can command a premium price. Synthetic pigments, and in this instance iron oxides, are those pigments produced from basic chemicals. Through chemical synthesis pigmentary sized particles are produced as opposed to comminution, the major procedure common to all natural iron oxide pigments. Classification An important characteristic of a pigment is its color and, therefore, a logical separation can be made on this basis. A. Yellow Iron Oxide Pigments 1. Natural mineral origin a) Goethite b) Lepidocrocite c) Ochres d) Siennas e) Limonite 2. Synthetic pigments a) Goethite B. Red Iron Oxide Pigments 1. Natural mineral origin a) Hematite b) Siderite (calcined) c) Pyrites (calcined) 2. Synthetic pigments a) Hematite C. Brown Iron Oxide Pigments 1. Natural mineral origin a) Umbers b) Limonite (calcined) c) Siderite (calcined) d) Goethite (bog ore or sulfur mud) 2. Synthetic pigments a) Blends of hematite, goethite, and magnetite

Jan 1, 1983

By W. F., Dietrich

THIS paper deals with the- methods of mining the high-grade clays of California. Although the majority of the clay pits in the state are operated on a scale that is small by comparison with most metal mines, this very fact results in a diversity of methods and gives rise to problems of selection of the method best suited to given conditions. Two or three operators in California produce approximately 500 tons per day of a single kind of clay from a single pit. About five varieties of clay are mined on a scale of 200 to 400 tons per day; not over fifteen varieties are mined on a? scale of 50 to 200 tons per day; and more than 50 varieties are mined at a rate of less than 50 tons per day. It is the aim of this paper to delimit, insofar as the data at hand permit, the conditions and scale of operations that favor the selection of each dominant method of mining that is actually being applied at California properties. Details of the occurrence and utilization of the clays of California have been given in a recent bulletin and are not considered here.

Sep 1, 1928

By R. L. Loofbourow

SEVERAL categories of storage are used depending on capacity. Operational storage, which is small in comparison with the market, facilitates handling surges of a few hours' or a few days' duration. Seasonal storage, usually larger, permits accumulation of product during sea- sons when demand is low, for delivery when demand is high. In producing areas, large storage may permit production at a uniform rate, without waste or distress sale. Near large markets such storage increases the efficiency of transportation, allows a more extensive or higher grade market to be served, and affords protection against interruption in delivery.

Jan 1, 1959

By B Rouvray, R Bertuzzi

The development of a design-and-construct tunnelling project in Australia from its concept to its construction requires designs to be prepared and reviewed at several distinct stages prior to documenting ‘for construction’. On recent projects the post-tender stages have been variously called 30 per cent—70 per cent—100 per cent; or concept–substantial–final; or system definition–preliminary–critical. The design is reviewed at each stage by the designer’s internal reviewer, the contractor and its independent advisor(s), the owner and its independent advisor(s), the project’s independent certifier, proof engineers and often third-party stakeholders and their advisors. Documentation for each stage often dominates the design effort, at times distracting from design. This paper presents the authors’ experience of this design-and-review process. Comparisons of design budget and actual design spend and design program implications are presented. It is postulated that a subtle change has occurred in our industry that has diminished the value of the design dollar. Is there a better process? An alternative is suggested.CITATION:Bertuzzi, R and Rouvray, B, 2014. Reducing the cost of tunnel design in Australia, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 501–506 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By J. M. King

A crucial step in the acquisition by one company of the assets of another, the acquisition of the stock of another company, or the merger of two com-ponies, is the legal due diligence which needs to be performed in order for the acquirer to ascertain or confirm the obligations, liabilities and exposures to risk that are being assumed along with the assets or corporate stock being acquired. Where the obligations, liabilities, or exposures to risk arise from existing contracts, or from pending lawsuits, administrative proceedings, or threats of these actions, those matters are relatively straightforward to discover by careful review of the files of the party whose assets or stock is being acquired. However, where a company is engaged in ongoing mining or processing operations and has operated or owned mining proper-. ties, there are many sources of liability and exposure to risk which could have major adverse economic consequences to the acquiring party and which are not revealed, or at least are not clearly delineated, by the records of the company whose stock or assets are being acquired.

Jan 1, 1990

By Sparrow GJ, Woodcock JT

A sample of pyrrhotite flotation concentrate pulp assaying 15.3 g/t An, which had been prepared from an old tailing dump, was treated to extract the gold. Examination of the concentrate with an SEM showed that exposed or free native gold, 5-40 ¦m in diameter, was present but no locked gold was observed. Direct cyanidation of the concentrate to extract the gold showed that the flotation reagents present inhibited gold extraction. A range of pre-treatments was used to overcome these effects.Direct cyanidation for 48 h extracted only 26% of the gold, indicating possible contamination of the gold in the concentrate with flotation reagents. Pre-treatment of the concentrate pulp by aeration for 24 h, or by 72 h aeration with an addition of 3.65 kg/t of sodium sulphite, gave little improvement in gold extraction by subsequent cyanidation. Pre-treatment by filtration, or by aeration with 12.5 L/t 100 volume hydrogen peroxide, followed by cyanidation for 48 h gave gold extractions in the range 67-77%. Combining filtration and an aeration period with hydrogen peroxide addition raised the subsequent cyanidation extraction of gold to 88%, giving a tailing assaying 1.5 g/t Au.

Jan 1, 1990

By Anne Kvithydl

Printed circuited boards contain considerable quantities of valuable metal, while also containing many environmental pollutants making them unsuitable for landfill. In this study the decomposition of common plastics used in printed circuit boards were studied. Polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC) and polyethylene (PE) were heated in both CO, and argon atmospheres using a thermo-gravimetric furnace (TG) coupled to a mass spectrometer (MS). Soda ash Na,C03 and baking soda NaHC03 were used as reactants. The degradation temperatures and evolved gases are presented for single plastics and mixtures. Mixed plastics are shown to behave as a sum of the individual plastics. The mass loss temperature is the same in CO, and argon. However, less residue is formed when heated in CO,.

Jan 1, 2008

By Stephen K. Pave1

Over 1,100 tons per day of Fluid Catalytic Cracking Unit (FCCU) catalyst is used worldwide. During the cracking reaction, catalyst is contaminated by deposited metals including nickel, vanadium, potassium, copper, iron, sodium, etc. To compensate for contaminants, a portion of the circulating catalyst inventory is withdrawn for disposal and fresh catalyst is added. The DEMETR process takes spent FCCU catalyst and removes a portion of the metal contaminants, enabling the refiner to recycle demetallized catalyst, thus reducing the solid waste from the refinery. Through August, 1993, the operation of one unit for one refiner has resulted in the recycling of over 7,500 tons of spent catalyst.

Jan 1, 1994

By Eric R. Bauer

The ground control aspects of extended depth-of-cut mining are presented in this U.S. Bureau of Mines report. A trend analysis of extended cut approvals was performed. A comparative review of roof fall fatalities for extended and nonextended cut mining is included. Current ground control guidelines for extended cut approval are summarized. The problems and concerns of this extraction system are addressed, and typical extended cutting face operations are described.

Jan 1, 1993

By B. S. Xakalashe, I. J. Geldenhuys, B. Bowman, M. W. Erwee, G. A. Venter, J. Zietsman, C. Sandrock, Q. G. Reynolds

Understanding the behaviour of plasma arcs is an important part of the design and operation of direct current electric arc furnace smelting processes, which are used in the industrial production of many metallurgical commodities. In recent years numerical and computational modelling techniques have begun to illuminate the complexity of arc behaviour and how it is deeply connected to the thermodynamic and physical properties of the arc plasma. Plasma properties may be estimated from first principles using statistical mechanics methods, but this requires as input some knowledge of the composition of the gas phase that occurs over the process during smelting. In this paper the authors describe a workflow using thermochemistry software to predict the expected gas phase composition through a given process, followed by plasma property calculations using an open-source software tool that has been in development for several years. This tool, 'minplascalc' has been in development for several years and is also described in detail here. The workflow is then applied to the calculation of plasma properties of interest for a variety of historical and current pyrometallurgical processes, and the results are compared. The plasma property data are published in an open-access database for general use.

Mar 4, 2025

By H. P. Cole

A team of researchers at the University of Kentucky, working under a USBM contract, developed over 65 simulation exercises for teaching and testing problem-solving and decision-making skills to miners and mining engineers. These skills involve both improving judgment and decision making in mine emergencies and enhancing the learning of real-world engineering design principles. The exercises are ideally suited for either latent image format or for computer-aided instruction. Exercise features are summarized, the structure and field testing of typical exercises described, and sample frames of individual exercises presented. Empirical data are summarized that describe the effectiveness of using these short, time-efficient performance tasks that simulate real problems and that provide immediate corrective feedback for teaching and testing critical skills. I

Jan 1, 1991

By Reinhardt Thiessen

In the general study of coal, all evidence points in the one direction —that coals had their origin in a manner analogous to that of peat. The best method of studying coal, whether it concerns its chemistry, composition, or physical condition, is to study peat. The essentials in a study of peat are a knowledge of the chemistry of plants, knowledge of decay and of the transformation process of plant-substances into peat. A number of facts must be emphasized, namely, (1) peat is formed under wet conditions only; (2) plants grow in the place where peat is formed; (3) all the plant substances go into the bog; and (4) all the plant substances are subjected to a series of phases of decay which are (a) in the air completely above the water level but in relatively moist conditions; (b) above the water level, but covered by debris; and (c) completely submerged by both water and debris. Plant Chemistry Plant chemistry as a whole is remarkably well understood. The number of compounds composing plants is large, and it is not possible here to give even a comprehensive outline, but a classification into definite groups is possible; this is as follows: Carbohydrates; glucosides; pigments; tannins; acids, alcohols and ketones, etc., and their salts; essential oils; resins; vegetable bases; proteins; enzymes. Plant substances may also be grouped according to the role they play in the life of the plant, such as: Framework materials, living materials, food materials, protecting materials, waste materials. While this classification groups them well for. certain purposes, it does not group them exactly chemically; but in a consideration of the composition of coal, this is an excellent classification for our purpose here.

Jan 1, 1925

By B. K. Cantrell, K. L. Rubow

"The US Bureau of Mines and the University of Minnesota have developed design and performance criteria for a personal diesel exhaust aerosol sampler for underground coal mines. These are based on the premise that size can be used to separate diesel exhaust aerosol, which is mostly submicron in size, from coal dust aerosol, which is mostly greater than a micron in size. The sampler has three stages: a respirable aerosol preclassifier, a 0.8-um aerodynamic diameter inertial impactor to collect mineral dust and a final filter to collect the diesel aerosol. Using a sample flow rate of 2 L/min and gravimetric analysis to within 0.1 mg, the measure sub-0.8 um diesel aerosol has an a-priori limit of detection of 0.3 mg/m3.A miner working in an underground coal mine with diesel equipment is exposed to a wide array of pollutants from the diesel exhaust. These include CO, CO2. NO, NO2, SO2, diesel exhaust aerosol, and a variety of hydrocarbon compounds. A quantitative definition of the health risk resulting from these exposures remains elusive. During the past several years, though, progress has been made in defining the problem.Results from epidemiological studies by Garshick et al. (1988 ), animal inhalation studies by Mauderly eta). (1986), Iwai et al. (1986), and Brightwell et al. (1986) and in vitro studies by Lewtas et al. (1986) have provided sufficient data for the National Institute of Occupational Safety and Health (NOSH) to recommend that ""whole diesel exhaust be regarded as a 'potential occupational carcinogen,' as defined in the Cancer Policy of the Occupational Safety and Health Administration"" (NIOSH, 1988). NIOSH further stated that ""though the excess risk of cancer in diesel-exhaust-exposed workers has not been quantitatively estimated, it is logical to assume that reduction in exposure to diesel exhaust in the workplace would reduce the excess risk.""The Mine Safety and Health Administration (MSHA) has also been directed by an advisory committee to establish a diesel exhaust aerosol standard and to establish regulations to minimize exposure to diesel pollutants in underground coal mines (MSHA,1988). Both reports point out the need for development of measurement techniques for respirable diesel aerosol.In the past four years, the US Bureau of Mines (Cantrell,1987 and Cantrell, et al. 1987), in cooperation with Marple, et al. (1986), at the University of Minnesota's Particle TechnologyLaboratory (PTL), have studied the use of size-selective sampling techniques to measure the mass concentration of diesel aerosol in underground coal mines. Results from these studies have been used to develop design and performance criteria for a personal diesel exhaust aerosol sampler for use in underground coal mines.These criteria are based on the premise that size-selectivesampling techniques,can be used to separate diesel exhaust aerosol, which is predominantly submicron in size, from coal dust aerosol, which is mostly greater than a micron in size. In addition to the performance criteria, this paper discusses the laboratory and field test data used to develop the criteria."

Mar 1, 1992

By H. L. Holden

The single line grinding circuit at Bond Gold's Colosseum mine consists of variable speed drive semi-autogenous (SAG) milling and secondary grinding with a fixed speed ball mill. There are several advantages and disadvantages of operating SAG mills with variable speed drives. Discussion in this paper will focus on the effects of variable speed SAG milling in relation to mill liner wear, grinding media consumption, and mill operating availability. Operating experiences, corresponding mill data, and pertinent design changes are also presented.

Jan 1, 1991

By R. O. Burt

The original flowsheet of the TANCO mill consisted of a simple two-stage gravity circuit for the recovery of the tantalum concentrates. With decreasing grade and grain size of the tantalum minerals, considerable modifications to the circuit have been required. This paper discusses the various recent improvements carried out 011 all stages of the flowsheet, which have resulted in a 10% increase in recovery. Future improvements, including on stream analysis, and the possibility of tantalum flotation , are also discussed.

Jan 1, 1979