Search Documents

By Drew Floyd

Five full-scale pile load tests were performed on pairs of PZ-22 sheet piles installed with a vibratory pile driving hammer. The sheet piling was installed in several locations in soil generally consisting of miscellaneous granular fills overlying soft organic silts, inorganic silt interbedded with sands and gravels, very dense glacial till and shale bedrock. The test program also included the use of tip tell tales to determine what capacity could be attributed to tip resistance and skin friction. During the design phase of the project, it was assumed that the capacity of the sheet piles driven with the vibratory hammer could be correlated with the rate of penetration. The correlation between vertical capacity and rate of penetration would be used as a basis for determination of a driving criteria from driving the production sheet piling. The sheet piling load tests demonstrated that it was not possible to correlate the capacity of sheet piling driven with a vibratory hammer and the rate of penetration. It was also demonstrated that the capacity of the sheet piles was directly related to the density of the soil at or just below the tip. The results also tend to agree with empirical equations provided by Meyerhof (1976).

Jan 1, 1989

By S. H. Jason Choi

The Systems Conveyance and Operations Program (SCOP) is being implemented to convey tertiary-treated effluent to Lake Mead near Las Vegas, Nevada. The Reach 3 Tunnel Project is part of SCOP. The tunnel?s planned location along and across the Las Vegas Wash creates challenging tunneling conditions. A number of feasible excavation and initial support methods are being considered during the final design stage. This paper describes how the tunnel construction options were refined based on anticipated tunneling conditions and compatibility between tunnel excavation and initial support methods. A brief description of the most significant characteristics of the anticipated ground conditions is included for the purpose of discussion.

By G. Papachristodoulou, O. Trass

"Performance data for both wet and dry grinding of materials have been obtained in this novel, planetary ring-roller mill over wide ranges or operating conditions. The Szego mill consists of a stationary cylindrical shell inside which grooved, radially mobile rollers rotate, driven by a central shaft. The mill has several internal design variables such as number, diameter and length of rollers as well as size, shape and pitch oi helical grooves. It is compact, has a high specific capacity, modest power consumption, and can grind many materials down to ultrafine powders. Illustrative data on product fineness and mill power consumption are given along with results from studies on grinding kinetics.INTRODUCTIONThe extensive use and importance of grinding as a unit operation, coupled with the rather low energy efficiency of conventional equipment provide a challenging incentive to investigate novel methods of comminution. Yet, most current development work is taking place in mill performance modelling and optimization, or with various detailed improvements rather than in the field of new equipment development.This paper is a report on the development of a ring-roller mill invented by the late L.L. Szego which embodies several novel concepts. The mill has a broad range of applications, may be operated wet or dry, and can grind materials down to ultrafine sizes with modest energy consumption. It has been developed by General Comminution Inc. in close cooperation with the University of Toronto."

Jan 1, 1986

By Frank R. Field, Randolph E. Kirchain, Elisa Alonso

"There are a number of environmental incentives for increasing recycling, including the reduction of waste, energy and resource use. Recycling can also be advantageous for manufacturing firms in both the short and long term. Secondary material can substitute for primary material, potentially dampening primary material price increases and reducing the pressure for greater primary extraction. This paper examines the potential for and dynamics of recycling for the case of platinum using a dynamic, behavioral simulation model of the primary and secondary markets. Since the secondary supply of platinum depends on a supply chain separate from primary extraction, recycling can diversify the risks of primary supply instabilities. Over time, recycling can cut primary consumption, reduce overall costs to firms, and possibly reduce the impact of price fluctuations upon firms.IntroductionThe benefits of recycling, from the perspective of the environment, are many, and the environmental benefits of increased recycling are considered a step towards increased sustainability [1, 2]. Life cycle assessments indicate that obtaining materials from secondary sources generally requires less energy and has fewer environmental impacts than extraction and refining of primary materials [3]. Analyses of materials flows show that, in addition to landfill volume reduction, recycling reduces primary material consumption, affecting long term materials scarcity [4, 5].The benefits of recycling are not limited to the environmental. Firms can benefit from the lower energy costs of recycling, especially that of metals whose primary extraction and refining are particularly energy-intensive (e.g., aluminum). The routine participation by firms in secondary materials markets (e.g., www.recycle.net) shows that this advantage has not gone unnoticed.Recycling can also benefit firms whose costs can be significantly affected by changes in material prices resulting from material shortages and material scarcity, with potentially permanent effects upon firms [6-8]. This paper focuses on the impact of recycling in the face of platinum scarcity for supply chain downstream firms."

Jan 1, 2008

By Patrik Ericsson

During the 90?s Atlas Copco and LKAB developed a pioneering fully automatic long hole production drilling system based on the Atlas Copco Simba W469 drill rigs. These drill rigs have since then drilled about 8.000.000 drill meters at the LKAB Kiruna and Malmberget mines. In 2005 LKAB ordered three new Atlas Copco Simba W6 C, to complement Simba W469s still in operation. These new Simbas are based on the latest generation computerized drilling technology have proven to meet the expectations of LKAB and now form a base for future automation in Kiruna and Malmberget mines. This paper will present experiences from the introduction of Simba W6 C in LKAB Kiruna and Malmberget mines. The paper will also elaborate on the latest developments in remote access and remote control technology making it a common automation option available for all computerized Atlas Copco drill rigs.

May 1, 2007

By H Kurth

Geoscan is used for multi-elemental analysis of conveyed bulk materials in real time. It has been used for coal analysis since the 1990s, in the cement industry, and since 2003 for measuring mineral ore quality. Geoscan-M has proven performance and demonstrated paybacks of weeks or months, in iron ore, manganese, copper, zinc-lead and phosphate industries. Geoscan-M measures continuously through the full bed depth and is unaffected by belt speed, particle size, layering and dust levels. Increments of two minutes (typically one to five minutes) are accurately measured and provide the plant operators with tonnage weighted results of each element within seconds.A Geoscan installed after crushing is able to measure quality shortly after mining. The analysis results can be used to divert the increments based on composition, such as diverting waste for disposal and diverting marginal material to a stockpile for processing at a later date. The bulk sorting process allows different qualities to be placed into relevant stockpiles for subsequent blending. Material meeting product DSO (Direct Shipping Ore) quality can bypass a beneficiation circuit to prevent unnecessary treatment costs. An analyser in a blending application enables proportioning of different quality feed materials from multiple stockpiles to achieve a desired compositional consistency for process feed. The parameter used for decisions may be; a) primary metal content, e.g. Cu, Fe, P, etc. b) deleterious component content, e.g. Mg as an indicator of talc content, c) process parameter content, or a combination of these. Process parameter content may be the elemental ratio between critical components, e.g. Cu:S ratio, Fe:Si ratio, basicity, Lime Saturation Factor, etc. or the content of an “indicator” element, e.g. Si as an indicator of material hardness or grindability.Measurement of the composition in real time enables prompt feedback to the mining operators and also feed forward to the process operators. Compositional variability can be critical in the process and advance warning enables appropriate reactions prior to processing. This may include modifying the feed rate, changing the feed blend (through additives), or modifying reagent dosing in anticipation of a change in feed quality. Benefits include, but are not limited to; reducing waste processing, improved feed grade stability, reducing energy, water and grinding media consumption, producing less tailings, increasing process efficiency, higher metal recovery, better plant utilisation, reducing plant downtime, better utilising mined material, all achieved using the same process plant throughput capacity.CITATION:Kurth, H, 2015. Optimising plant feed quality and process performance using Geoscan elemental analysis, in Proceedings MetPlant 2015, pp 373–380 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

Collins Radio Company, through this contract with the Bureau of Mines, has conducted a System Study of Coal Mine Communi¬cations. The program was a three phase program to establish a data base, perform communication system analysis and optimi¬zation, and prepare equipment specifications to be included in this final report. At the start of establishing a data base both a knowledge of mine communication and coal mines in general was obtained. Communication system requirements and constraints were determined along with a survey of current and potential mine communication equipment. An investigation was completed concerning theoretical LF and VLF propagation characteristics, and UHF propagation tests were conducted in a working coal mine. Different mines were contacted and on-site surveys completed with respect to coal mine communication requirements.

Jan 1, 1973

By John S. Alexander

By Manuel Gomez

Published experimental coke data from a pilot plant slot-type oven were examined by statistical regression analysis. Quantitative relationships were found to exist between the coking rate, bulk density, and fine grinding of the coal, sole-oven expansion, volatile matter, moisture, ash, and carbon con-tent of the coal and coke parameters indicative of size and strength. Regression equations developed from coke data were shown to yield computed values that were in good agreement with experimental results for 11 coke properties. Prediction equations developed were evaluated with an independent set of data. Present results indicate that the variables cited undergo much interaction and the sum of these interactions determines coke size and strength.

Jan 1, 1967

By B. Asbury, M. Cigla, C. Balci

The Western Mining Resource Center (WMRC) at the Colorado School of Mines (CSM) received a grant from the National Institute for Occupational Safety and Health (NIOSH) to perform a study that will help reduce the amount of respirable dust generated from the cutting of coal. The study is based upon laboratory testing and field experience. This information is being used to develop a new cutterhead design in conjunction with Joy Mining Machinery. The new cutterhead design is being evaluated with existing computer models developed at CSM. The new continuous miner cutterhead will be tested at the Twenty Mile Coal Company’s Foidal Creek Mine. Baseline testing with the current cutterhead will also be performed. This paper presents laboratory test results, design methodology, and test results performed to date.

Jan 1, 2002

In attempting the predict coal cleat orientation in the subsurface for effective methane degasification of the coal beds in the Warrior coal field of Alabama, approximately 150 rock joint orientations and 45 coal cleat orientations were measured in each of 37 7 ½ minute quadrangles in Tuscaloosa, Walker, Jefferson, Fayette, Winston, Blount, and Bibb Counties. Data from these surface locations, and coal cleat data from eight underground mines was corrected for magnetic declination and titled beds rotated to the horizontal where necessary and plotted on rose diagrams for comparative analysis. Data collected on each joint and cleat consisted of attitude, quality, type, spacing, persistence, lithology, bedding thickness, surface texture, and filling. File data and published and unpublished reports from the State Survey and the State Mine Inspector's Office were re-viewed. Twenty-seven mining companies, most of which supplied information pertinant to the project were also contacted. The information obtained consisted of crop line information structure, and underground mine outlines, all of which were put on 7 ½ -minute topographic quadrangles. LANDSAT-1 imagery and Skylab photography were compared to dominant joint and cleat trends in the study area. Detailed results can be found in an open-file report entitled "Fracture Analyses in a Selected Area of the Warrior Coal Field, Alabama." A master's thesis entitled "The Relationship Between Surface Joints and Subsurface Structure in a Selected Area of the Warrior Coal Field" is being prepared to illustrate the relation-ship of the fracture system to the structure in the Warrior coal field. A proposal has been submitted for research on a project entitled "Rock Fracture Systems and Their Affects on the Extraction of Fossil Fuels in the Warrior Basin, Alabama"

Jan 1, 1976

By J. A. Meech, R. J. Tucker

"A dynamic computer model has been developed to simulate the operation of ore crushing plants. The model was created in a general form to allow imitation of a wide variety of secondary crushing circuits with only minor program modifications. The system can be run on either a microcomputer or a large time-sharing main frame computer as required.The size reduction and separation characteristics of crushers and screens are based on standard manufacturers' design and performance data. These calculations are isolated within various subroutines to facilitate tailoring of the model to emulate any particular plant of interest. Input and output data are presented in a variety of formats. Crusher, screen and conveyor amperages and surge bin levels can be presented in a tabular form along with appropriate alarms arising from improper circuit operation or process interruptions. Graphical representation of the circuit together with strip chart data output are features of the system when operated in a microcomputer environment.The program is currently being used at Queen's University as a teaching aid to demonstrate plant operating characteristics, control strategies and design concepts. The acceptance of, and reaction to the program at this level indicates a good potential for it to provide a valuable tool for operator training."

Jan 1, 1985

By George S. Barnett

The Equis and El Roble projects are located in the Cordillera Occidental of Colombia. The Equis vein deposits have sulfide ore reserves of 95.9.5.5 mt (105.770 st) grading 8.51 g/mt (0.248 oz/st) gold and 12.4 g/ml (0.36 oz/st) silver with 0.94 % copper. 1.10 a lead and 11.06% zinc. Ore reserves at El Roble are estimated as 1.1% Mmt (1.21 million st) grading 4.89% copper and 3.39 g/mt (0.099 oz/st) ,old. Geologically possible reserves at Equis may total 1.6.Mmt (1.76 million it). El Roble has the potential to contain several tens of millions of metric tons. Exploration included diamond drilling, trenching, channel sampling, rock and soil geochemistry, geophysics and tunneling. Erratic high grade samples affect the weighting of channel and drill core samples. Secondary reconcentration of gold is also a factor. Sample maps and graphs show the distribution of values to be highly variable. Geostatistical treatment of some of these data gave important guidelines for parameters such as sampling densities, drill hole spacing and confidence limits.

Jan 1, 1984

By J. G. Ross

IN the paper entitled Block Caving at the King Mine (1), which was presented at the Annual General Meeting held in April, 1934, at Quebec, it was pointed out that, owing to certain conditions and financial restrictions, it was advisable to provide a temporary shaft. This was raised from the )00-ft. level to the bottom of the pit, and a 45-degree incline track was constructed up the face of the pit to surface. The temporary shaft and incline were within the ore-body, but were to be used only until such time as the new shaft-the subject of this paper-could be sunk and made ready for operation. After a careful study had been made of all available information pertaining to the ore-body, including examination of diamond-drill core records and geological data, a shaft location was selected well outside the ore-body. Further, since the crusher and dryer buildings are located over part of the ore-body, it was necessary to plan the removal of these buildings and to construct a new crushing and drying plant. This, and the new shaft, must operate in conjunction with the present mill and rock storage bin, which would continue robe used as formerly. No part of this programme, with the exception of drifting toward the shaft site, was started prior to 1937. More than usual detail on technical features is given in this paper in the hope that some parts of it may be of assistance to other members of the Institute who have to undertake somewhat similar work. The engineering and operating staff designed and supervised the work, while at the same time carrying on regular production in four mines at the rate of 12,000 tons of rock mined per day, the output at the King mine being at the rate of 140 tons per hour. No additional engineers were required.

Jan 1, 1939

By Jom Kresta

Fundamental changes in the Bitumen Production process at Syncrude have led to the integration of Mining and Extraction operations. Successful operation of the integrated process requires the coordinated effort of several business units. Hence, decision-making has become increasingly more complex and better tools are required. IO2 is a collaborative effort to develop a proof-of-concept prototype of a distributed decision-support system for integrated short-term production and maintenance planning with fleet allocation and dispatching. The prototype includes three main modules (planning, dispatch, and maintenance), a shared database, and a simulation module. At this stage, this prototype is used to plan and operate a simulated mining operation. It is used to demonstrate the viability of the chosen systems architecture and algorithms, as well as the information flows and interactions necessary for improving the overall performance of the integrated operation. While the problem is demonstrated using Syncrude?s site, the methodology is applicable to most integrated resource allocation problems.

May 1, 2002

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"The steps from experimental curiosity through to commercial product can be slow and tortuous in spite of the quality of the technological advances offered by the new development. Data generation and interpretation need to be done in lab tests as well as full-scale evaluations and, in each, the advantages of the new reagent must be clearly identifiable and measurable.The Dow Chemical Company has patented a novel new collector for the flotation of zinc. Fl (2-hexylthioethylamine hydrochloride) has several unique structural features that suggest atypical mechanisms for zinc collection. Laboratory data have demonstrated significant flexibility with respect to grade and recovery balance at dosages lower than those typically used for xanthates.In mill trials, the same phenomanon is evident - the choice between high grade and high recovery allows one to select the desired quality of zinc concentrate. One trial in particular was run over a three month timeframe and Fl gave improvements in recovery of 2.5% and a reduction in lead levels with less than 0.5% loss in grade. The dosages of other reagents in the flotation circuit were also reduced.Data demonstrating improved recovery and grade in lab trials will be discussed. Extensive data from the mill trial will illustrate how Fl works in both rougher and cleaner circuits."

Jan 1, 1990

By W. K. Gowans

The Sullivan Concentrator treats a complex sulphide ore consisting mainly of galena, marmatite and pyrrhotite. The ore carried minor values in silver, antimony, bismuth, indium and tin. The products of the concentrator are lead, zinc, iron and tin concentrates. The minor metal values other than tin are recovered from the concentrates by the refining processes in the smelter at Trail.The concentrator was completed in 1923 and first operated with a capacity of 2,500 tons per day. In the years 1926 to 1929 changes to equipment and buildings brought the operation up to 5,500 tons per day and then, in the years 1935 to 1945, the daily tonnage was raised to 8,500 tons. After 1945, the rising insoluble content of the ore made it necessary to consider the construction of a Sink-Float plant. At this time consideration was also given to the construction of a new crushing plant underground to replace the rolls crushers and cone crushers located at the concentrator. By 1949, construction of the Sink-Float plant was completed along with a new underground crushing plant, and an electric haulage way between the underground crushing chamber and the Sink-Float plant. The ore was hauled in forty 14-ton car trains which discharged into a 3,000 ton receiving bin by means of an air operated five car rotary dumper. With the start up of the,Sink-Float plant, a 1 ½ ft. by 12 ft. Hardinge rod mill was also brought into operation. The Sink-Float plant made it possible to treat 12,000 tons/day of mine run ore with up to 40% of this being rejected as float.

Jan 1, 1975

By T. Weatherwax

As part of a strategic research initiative at UBC to design and evaluate integrated underground mining and mineral processing systems, work has been done to determine how to utilize the coarse rejects of pre-concentration in the underground environment. An amenability study for nine orebodies from four of Xstrata Nickel?s Ontario operations evaluated both processing and waste disposal methods. The utilization of the rejects as a high quality backfill with minimal binder requirements has been identified as the preferred disposal method. Fill mixes utilizing the rejects in combination with classified tailings, full tailings, and cement were developed based on the geotechnical properties of the rejects. The mix designs were examined for both strength and rheological properties. The paper will present the results of the pre-concentration testwork, the design and strength testing of various mix designs for rejects from the nine ores and presents a conceptual design for an underground pre-concentration system based on this test work.

Jan 1, 2008

In the last two years the Commission for the Environment has received four Environmental Impact Reports (EIR) for Audit and has been or is involved with at least four environmental impact assessments (EIA) related to mining. The EIRs have included Weavers Coal Mine, the Monowai-Maratoto mining proposal, the Martha Hill mine and the Wainui Road Mill. The EIAs are related mainly to coal fields in the Waikato but also included a further EIA on Martha Hill.

Jan 1, 1986

By J. H. Zietsman, M. W. Erwee, P. J. A. Bezuidenhout, Q. G. Reynolds

"Pyrometallurgical furnaces are tapped through tap-holes that are opened with drills and oxygen lances. The lance is often used on its own or as the last step of opening the tap-hole. Interaction of oxygen with molten material inside the tap-hole can occur, and is a phenomenon that is not well understood. As part of a study that focuses on the effect of lancing on flow inside and around the furnace tap-hole, a cold-model validation was done. The validation study focuses on validating the MULTIPHASEINTERFOAM multiphase flow solver in OpenFOAM® for the problem involved. The sensitivity of the model to different materials properties (viscosity and density in particular) is presented with both cold models and the results from flow simulations in OpenFOAM®. IntroductionMany pyrometallurgical operations are carried out in furnaces where molten material accumulates continuously. Once enough material has accumulated and is ready to be removed from the furnace, material is tapped through one or more tap-holes in the furnace. Tap-holes differ significantly in both geometry and materials of construction, depending on the process involved – examples of different types of tap-hole configurations can be found in, for example, Nelson and Hundermark (2014). Tapholes all share one common feature: they are high, wear areas of the furnace. Molten material at high temperature flows through these areas, after which the tap-hole is sealed, usually using tap-hole clay. The purpose of the tap-hole clay is to harden inside the tap-hole and seal it until the next tap.Once ready to tap, a pneumatic drill and/or oxygen lance is used to open the tap-hole. The extent of lancing a furnace tap-hole depends strongly on the type of furnace. In, for example, many blast furnace operations lancing is limited as much as possible, and done only if drilling was not effective. In other operations, such as on small-scale pilot furnaces with short tap-holes, only lancing is used to open the tap-hole."

Jun 1, 2019