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By T. Lamb, T. Aston

"The Gays River Mine is located within a complex hydrological regime and underground mining environment. Early in the mine history, the operation was' affected by an inability to control mine water inflows. More recently, the reopened mine operation had been unable to maintain consistent drainage of groundwater to the mine workings and sustain low groundwater levels.In 1992, a series of investigations were completed, which in part Were funded under the Canada-Nova Scotia Mineral Development Agreement. The studies undertaken included: hydrochemical and drainhole well screen assessments, an air photo study of sinkhole features, numerical modelling studies and a major piezometer installation and overburden soil study. The results indicate that the water draining to the underground workings is comprised of two distinct components: precipitation over the drawdown cone catchment area and seepage from the nearby Gays River. In addition, a third ""balance"" component was' also found, which represents uncertainties in the areal extent of the drawdown cone and river seepage components.After outlining the history of the groundwater problems experienced at the Gays River Mine, this paper examines the various studies undertaken during 1991-1992 and concludes that control of groundwater levels in the mine area is achievable. A number of recommendations are also proposed for future study ."

Jan 1, 1993

By Anuj Narang

Large-scale separation or flotation cells, used in the primary extraction in the oil sands industry, are integral parts of the overall process of bitumen extraction. Good regulation of the interface level between the bitumen froth and the middlings in these cells can result in a significant improvement in bitumen recovery and throughput, and heavily influence process economics. Automatic control of such industrial processes presents challenges such as multi-phase flow dynamics, variable process gain and time delays, poor quality of measurements and significant disturbances. This paper details a case study application of development of multiple models of the dynamics of the interface level and the design of model predictive controllers (MPC) for a separation cell process. A Model predictive controller (MPC) using linear models is designed and implemented in real time on an industrial separation cell. The industrial implementation results show that the MPC scheme provides significant benefits over the current operations which use a PID controller. The benefits include significant reduction in the variance of the interface level resulting in higher bitumen recovery and smoother downstream operation plus energy savings due to reduced underflow pump speed.

Sep 1, 2012

By Jenny Alsén, Hans Hogard

"Construction of large facilities underground in urban areas has many advantages. In order to show the advantages, a case study of the Norsborg metro depot in Stockholm Sweden has been made. The Norsborg metro depot will be the largest and most modern underground metro depot in northern Europe. The depot has been built in hard rock in an urban area with small impact on the environment and local residents. The paper describes how it is possible to build underground facilities in a cost efficient way and take care of the challenges regarding working environment that comes with locating a permanent working place underground. INTRODUCTION The Stockholm area is one of the five fastest growing regions in Europe and home to more than a fifth of Sweden's population on just two percent of Sweden's surface. The population is growing rapidly, with about 35,000 people per year and is expected to reach 2.6 million in 2030. In order to meet the development and enable continued growth, housing projects and expansion of infrastructure need to keep the same pace; this is an easy conclusion to make but much more difficult to realize in practice. The main challenge is to accomplish development in a sustainable and efficient manner, minimizing the use of resources and land. By constructing facilities underground more urban space will be made available for development and/or for greening of city centers. Considering sustainability factors such as land value in decision making for placing of structures or facilities, underground locations could become a first choice alternative. During 2015 and 2016, several major underground infrastructure projects in the city of Stockholm will start, including a 14 km sewage tunnel and an 18 km by-pass highway tunnel. Furthermore the Stockholm metro system is currently undergoing the largest expansion since the 1970’s, a 19 kilometers extension of the metro system including new trains and new stations is planned. During 2013 - 2015 Skanska Sweden took part in the construction of a new metro depot placed underground in the southern part of Stockholm; the Norsborg metro depot. This is a top modern urban underground facility that in 2017 will serve as depot for 17 new metro trains. The project was selected for “Outstanding Project of The Year” at the ITA Tunneling Awards 2015."

Jan 1, 2016

By David Cole

The appearance of the Wilfley table in 1897 marked an epoch in the art of concentration of ores. The table has merited and received an almost unprecedented measure of public approval, lasting through its whole patent life. It has been very little improved in itself, or improved upon by competitors. The new machines bidding for popular favor have been of the Wilfley family, but without ability to do markedly better work than the parent machine, or to do more work except by the use of superimposed decks, the latter having obvious disadvantages. During the past three years there has been developed at Morenci a new type or arrangement of riffles applicable to the Wilfley type of concentrating table which corrects many of the objectionable features or limitations of the older system and obviates most of the difficulties encountered with it, particularly when handling ores having a low ratio of concentration. The new type is known as the Butchart1 riffle system, and its general arrangement is shown in Figs. 1 and 2. The old system accomplished stratification satisfactorily but has

Jan 1, 1915

By G R. Hancock, W D. D P Welivitiya

is placed in a waste rock dump, which is usually later reshaped to be erosionally stable, initiate and sustain vegetation and ultimately integrate with the surrounding undisturbed landscape. However, it is unclear how this exhumed material will weather and evolve for most sites. Also, there is a lack of data on the weathering of post-mining materials. If weathering is better understood, then there is the potential to improve rehabilitation outcomes. To improve predictions of the evolution of soil properties and weathering-limited erosion, estimating the rate at which fine, transportable material is produced from the weathering of larger, non-transportable particles and the resultant fragment size distribution and how that distribution evolves over time is necessary. This study examines the weathering process for four different coalmine waste rock materials for a Bowen Basin, Queensland site. Materials obtained from various areas of the coalmine were subjected to cyclic wetting and drying and heating and cooling. Particle size distribution and other material properties were explored after each experimental cycle to ascertain how the material changes during the experimental cycles. The particle size distribution data of wet and dry cycles were used as input data in a numerical weathering model to explore the dynamics of the weathering process for each material sample. A Monte Carlo framework was employed to assess the geometry of the weathering products, weathering rate and the number of daughter particles produced within a weathering cycle. Then the SSSPAM Landscape Evolution Model was used to evaluate the influence of weathering on erosion and landscape evolution of a post mining landform. SSSPAM simulations with: (i) active weathering and (ii) without weathering were run for each material. The erosion rate and the overall landform structure were then compared between weathering and non-weathering simulations.

Aug 2, 2023

By Bartłomiej Bursa, Paweł Stefanek, Paweł Stefaniak, Sergii Anufriiev, Wioletta Koperska, Maria Stachowiak

The article presents the main functionality of the DSS class system for monitoring and stability assessment of tailings storage facilities. The presented demonstrator was deployed on the example of the Żelazny Most reservoir - the largest active facility of this type in Europe and the second one in the world. Considered a high-risk structure, it demands a system capable of online analysis of big data from various sources using machine learning, 3D modeling, or GIS mapping with the functions of interactive time-spatial analysis. In this paper, we present a complex calculation module with an integrated user interface.

Jun 25, 2023

By H. C. Miller

THE gas-lift method of flowing oil from wells is the outstanding feature of petroleum technology today. Its forerunner, the air lift, was used successfully first, in the Baku fields of Russia, in 1899, and later in the Gulf Coast fields of Texas and Louisiana and the Kern River field of California. It is still used to a limited extent in certain oil fields. The use of compressed natural gas for lifting oil from wells has supplanted the air-lift method in a measure in those fields where a sufficient quantity of gas accompanies the oil to make the gas lift possible, or where natural gas is plentiful and inexpensive. We find therefore in California, that, natural gas is used at practically every well where a gaseous medium is employed to flow the oil. The use of natural gas has many advantages over that of air. It is possible to recover and save the gasoline from the gas that accompanied the oil to the surface. This gasoline would be wasted if air were used as the lifting medium. Also, certain proportions of air and gas form an explosive mixture that cannot be handled safely by compressors. Another advantage that gas has over air is that gas under pressure is more soluble in oil. Gas in solution in oil reduces the viscosity of the oil that is being produced and causes it to flow more readily through the. tubing and flow lines. The gas lift has made it possible to recover many thousands of barrels of oil from deep wells in California that could not have been produced otherwise. It would not have been economical, had it been mechanically possible to produce such wells as the world's deepest producing oil well (Miley Athen's No. 6, Rosecranz field, California) by any other method of pumping known today. At this well, production is obtained from between 7305 and 7591 ft. and 11 months after completion of the well, production was being maintained on the gas lift it approximately 2000 bbl. a month. The crookedness of the hole, or its diameter and depth will not prevent the successful application of gas-lift pumping when other conditions are favorable.

Jan 1, 1927

The North Saskatchewan River flows southwest to northeast through a 22-km-long valley in the City of Edmonton, supplying the drinking water to dozens of downstream communities. During heavy rains, combined sewers occasionally overflow into the river, which has a significant negative impact on the water quality and the sensitive environment. The West Edmonton Sanitary Sewer (WESS) W12, a syphon connecting the Rat Creek Trunk to the Gold Bar Wastewater Treatment Plant across the river, was designed and constructed to take the overflow to the wastewater treatment plant. Due to the complexity of the project, various 3D technologies were applied to facilitate decision-making processes. 3D models were developed for design review and design conflict detection, while 4D models were established to help create a robust construction schedule. Construction sequencing animation was used to convey design intents and demonstrate construction stages to contractors and workers. The combined applications of 3D technologies helped the project team to identify critical issues, and assured effective communication among engineers, management, contractors, and other parties. Therefore, it provided more opportunities for the success of the project.

Aug 1, 2013

By George C. Howard, P. P. Scott

During the drilling of wells, fractures which are created or widened by drilling fluid pressure are suspected of being a frequent cause of lost circulation. A study of the variables which are believed by the authors to he related to fracturing led to the premise that the presence of an effective lost circulation material in a drilling mud stream would serve to plug small fractures at the moment they are encountered or created and thereby a a possible cause of lost Circula. tion by preventing fluid pressure from widening and extending the fractures. A large number of lost circulation materials were classified and tested in simulated fractures and in shallow wells. Granular type materials with a gradation of particle sizes were found to be the most effective for plugging. Within the limits of pumpahility, the concentration in mud of each lost circulation material tested was found to be a controlling factor in determining the maximum size fracture which could be sealed. A new type centrifugal sorter was given preliminary tests and found to be capable of concentrating cuttings for rejection and reclaiming lost circulation materials. INTRODUCTION The control and prevention of lost circulation of drilling fluids is a problem frequently encountered during the drilling of oil and gas wells. Lost circulation or lost returns may be defined as the loss to formation voids of the drilling fluids or cement slurries used in the process of rotary drilling and well completion. The loss may vary from n gradual lowering of mud level in the pits to a complete loss of returns. Not to be confused with lost circulation is the continuous reduction in mud volume caused by the loss of the fluid phase of muds as filtrate and the solid phase as filter cake during the continuous filt~ation process which occurs on permeable formation surfaces. The loss of drilling fluids and their costly constituents is only one of the detrimental effects experienced when circulation is lost. The loss of drilling time, plugging of potentially productive formations, stuck drill pipe, blow-outs, excessive inflow of water, and excessive caving of formatioils are other effects which contribute to make the control and prevention

Jan 1, 1951

By Fewings JH

When the mining and milling of 1100 Copper Orebody commenced, difficulties were experienced in producing a satisfactory grade of copper concentrate. The major concentrate contaminants were fine pyrite and silica, particularly in the minus 10 microns fraction. Studies of the 1100 Orebody showed that much of the fine grained pyrite and a proportion of the silica present in the ore contained carbonaceous matter in the form of complete or partial rims and as internal carbon films disseminated throughout grains. The hydrophobic surface property of the carbonaceous material resulted in an inherently flotable fine pyrite and silica fraction. The addition of a 60:40 mixture of nigrosine and dextrine, initially to a prefloat concentrate of the inherently flotable carbonaceous material and finally to'the total copper flotation feed, successfully controlled the flotation rates of the carbonaceous pyrite and silica. The objective of a 25 per cent Cu concentrate grade was then achieved without decreasing copper recovery.

Jan 1, 1970

By Michael Hoch, Michel Desjardins

The isothermal section of the Mo-Ti-Zr-0 system at 1500°C was investigated using X- ray diffraction and mefallographic techniques. Up to 66.7 at. pct 0, the system contains ten four -phase regions. Isopleths at 10, 30, 45, 55, and 60 at. pct 0 were constructed. THE purpose of this investigation was to determine the general shape of the quaternary equilibrium phase diagram of molybdenum, titanium, zirconium, and oxygen at 1500°C. The system was truncated at 66.7 at. pct o. PREVIOUS INVESTIGATIONS The Ti-Zr-0 system was investigated in this laboratory.' The binary systems of interest have been compiled and discussed by Hansen' and Levin, McMurdie, and Hall.3 Farrar, Stone, and Margolin studied the titanium-rich corner of the Ti-Mo-0 ternary. MATERIALS The titanium powder, 99.6 pct pure, the zirconium dioxide, and the molybdenum powder were supplied by the Fairmont Chemical Co. The zirconium powder,

Jan 1, 1962

By James L. Hendrix, Pat Vreeland, Hamilton Vreeland, Marcel F. DeGuire, Peter L. Comanor

A study of the ground area surrounding the Getchell, Nev., gold mine mill tailings was conducted so that a better understanding of the effects of arsenic toxicity on Upper Sonoran vegetation could be obtained. The Getchell area was selected because of the known high values of arsenic currently contained in the tailings waste (1% or higher). Mill wastes as well as the scrubber product As2O3 are contained in the tailings pond. In order to determine the effect of the tailings disposal on the surrounding vegetation, plots and line-transect techniques were employed to obtain plant ecological information on the area surrounding the ponds, and also non-affected control plots. Data for percent ground cover, species frequency, and plant vitality as a function of distance from the tailings ponds were collected. In an attempt to isolate naturally occurring factors for varying plant communities from induced factors derived from the close proximity of the tailings, soil cores were

Jan 1, 1975

By Canterford J. H, Bologiannis F, Smith A. N

The Mutooroo copper mine is one of a number of deposits that have been evaluated by Adelaide and Wallaroo Fertilizers Ltd as a source of feed for the production of high- purity copper oxide at their Burra plant. For this deposit, the technique of solution mining or in-situ leaching appeared ideal. The Mutooroo production circuit and the results of the process optimization and environmental monitoring programmes are outlined. At the end of the experimental period described here, the production liquor typically contained I g/litre copper, yield- ing in excess of 5 t/month of cement product containing about 80 per cent copper. The environmental monitoring programme provided clear evidence that there had been no un- acceptable alteration to the properties of the groundwater in the country rock surround- ing the mineralized zone. It is anticipated that the experience gained at Mutooroo will be of considerable help in the development of other solution mining operations.

Jan 1, 1983

By S. F. Shaw

In 1913, the Tiro General mine, at Charcas, S.L.P., Mexico, which had been making from 125 to 150 gal. of water per min., was allowed to become flooded, after all the pumps had been removed, and in 1918 the problem of unwatering it came up for solution. There are two vertical shafts, the Tiro General, 1390 ft., and the San Fernando, 1225 ft. in depth, with five connecting levels between them. The San Fernando shaft had been partly retimbered, while the Tiro General had been newly timbered from the collar to 1090 ft. in depth. It had been possible to place guides in only one compartment of the Tiro General, from the collar to the seventh or 850-ft. level, to which it was necessary to lower the water before station pumps could be installed. Soundings indicated that compartments in the Tiro General were open to 1082 and 428 ft., and in the San Fernando shaft to 471, 488, and 586 ft. The water had risen to a point 140 ft. below the collar of the Tiro General shaft.. Pumping Equipment The steam plant at the Tiro General shaft includes one 300-hp., one 150-hp. and one 100-hp. Erie City water-tube boiler, and two 160-hp. Heine water-tube boilers. All but one of these boilers were supposed to be in good shape, but it was soon discovered that six years of idleness in a climate that is foggy for several months of the year had left them in poor condition. The compressed-air plant comprises one Nordberg cross-compound compressor with piston displacement of approximately 2500 cu. ft.of free air compressed to 96 Ib. per sq. in.; and another Nordberg cross-compound with piston displacement of 1235 cu. ft. of free air, to the same pressure. The main pump station is on the seventh level where had been installed a Prescott pot-valve plunger pump with capacity of 200 gal. per min.; also a Gould triplex plunger pump with capacity of 135 gal. per min., driven by a 6 1/2 by 10 by 12 in. steam engine. From the lower levels, the water had been raised to the seventh level by small station pumps and sinking pumps.

Jan 1, 1920

By P. P. Scott, George C. Howard

During the drilling of wells, fractures which are created or widened by drilling fluid pressure are suspected of being a frequent cause of lost circulation. A study of the variables which are believed by the authors to he related to fracturing led to the premise that the presence of an effective lost circulation material in a drilling mud stream would serve to plug small fractures at the moment they are encountered or created and thereby a a possible cause of lost Circula. tion by preventing fluid pressure from widening and extending the fractures. A large number of lost circulation materials were classified and tested in simulated fractures and in shallow wells. Granular type materials with a gradation of particle sizes were found to be the most effective for plugging. Within the limits of pumpahility, the concentration in mud of each lost circulation material tested was found to be a controlling factor in determining the maximum size fracture which could be sealed. A new type centrifugal sorter was given preliminary tests and found to be capable of concentrating cuttings for rejection and reclaiming lost circulation materials. INTRODUCTION The control and prevention of lost circulation of drilling fluids is a problem frequently encountered during the drilling of oil and gas wells. Lost circulation or lost returns may be defined as the loss to formation voids of the drilling fluids or cement slurries used in the process of rotary drilling and well completion. The loss may vary from n gradual lowering of mud level in the pits to a complete loss of returns. Not to be confused with lost circulation is the continuous reduction in mud volume caused by the loss of the fluid phase of muds as filtrate and the solid phase as filter cake during the continuous filt~ation process which occurs on permeable formation surfaces. The loss of drilling fluids and their costly constituents is only one of the detrimental effects experienced when circulation is lost. The loss of drilling time, plugging of potentially productive formations, stuck drill pipe, blow-outs, excessive inflow of water, and excessive caving of formatioils are other effects which contribute to make the control and prevention

Jan 1, 1951

By S Tierney, D Cumming-Potvin, I Thin, Y Potvin, D Grant

The preliminary modifying factors for future stope design in the Southern Mine Area of Olympic Dam consisted of only a single, arbitrary value of Equivalent Linear Overbreak/Sloughing (ELOS). In order to improve this, a study was conducted which developed a more comprehensive methodology for assigning ELOS, Equivalent Linear Lost Ore (ELLO) and Equivalent Linear Fill Overbreak (ELFO) to individual stope faces based on geotechnical and mining parameters. The approach used was to look at the simple cases, which were classed as vertical stope walls in good ground (RQD 80-100%), divided into wall orientations (North, South, East, West). The stope walls were also split based on the blasting practice used (toeing, parallel or a combination of the two). The expected ELOS and ELLO from these ‘base cases’ are then modified by parameters which have historically been found to affect stope performance (Hydraulic Radius and Q’). The size of the effect found in the historical data determines the ELOS / ELLO applied. The methodology was summarised in an easy to use flow chart and was applied to all of the proposed stope shapes for the Southern Mine Area and summarised per mining block. This allowed each iteration of the mine plan to be assessed in terms of overbreak (both rock and vertical fill exposures) and underbreak.

Mar 15, 2021

By C. B. Manula, R. Venkataramani, T. V. Falkie

A linear programming model has been developed to solve a production planning problem for a multi-plant stone operation serving several customers. The factors considered are production capacities, inventory restrictions, demand requirements, and available stone reserves. The objective function to be optimized is the total annual net returns from the quarry operations. For the purposes of model testing, annual stone sales from each plant were divided monthwise, productwise, and assigned to a market. The concept of assigning demands to market sectors and not to any particular plant creates the self-correcting interplay between the plants and the markets. Along with the inventory restrictions, and ending inventory requirements, this interaction enables the model to minimize the external diseconomics. The model was tested against an operating prototype and a number of alternative problems were also considered. Finally, the basic linear programming model has been enlarged by the addition of another dimension and the problem has been derived in a decomposition format.

Jan 1, 1972

By S. Boisvert

Risk-based Inspection (RBI) addresses the challenges associated with ageing plants by focusing the inspection effort on the process equipments with the highest risk, thereby improving plant safety and reducing inspection costs. The RBI methodology is commonly used in the oil industry through the API 581 standard. Since no such standard exists in the mining and metals industry, BPR-Bechtel has developed one using inspection data from process equipments in CEZinc. Models were developed for various damage mechanisms, such as uniform corrosion and stress corrosion cracking. The equations were organized into a user friendly software that facilitates the implementation process.

Jan 1, 2010

By T D. H McGrath, O Baker, W P. Staunton, C Ypelaan

"The carbon-in-pulp process has been used extensively in the gold industry since the late 1970s to recovery leached gold from solution. Despite more than 30 years of experience in operating carbon circuits, average gold solution loss has remained at an average of 0.02–0.03 ppm (mg/L), higher than the ‘best practice’ target of 0.01 ppm.Process modelling, such as SIMCIL developed by the Curtin Gold Technology Group (GTG), can provide information on optimum set points; however, manual control of the circuit limits the potential benefits.An automated carbon measurement device, the Scout Carbon Meter, has been developed to allow for automation of carbon concentration measurement, and automated control of the carbon transfer pumps. This paper describes the results from the evaluation of the first two prototypes of the meter.Citation:Staunton, W P, McGrath, T D H, Ypelaan, C, Baker, O and Eksteen, J J, 2016. Optimising Carbon Management - Increasing Gold Recovery and Decreasing Costs with the Carbon Scout, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 225–228 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

By Theodore B. Comstock

The existing topographical features of the United States present many points of interest to the student of dynamical geology, but there is, perhaps, no subject which offers a more promising field for investigation than the relations between the geological structure and the mineralogical characteristics of the principal mining districts. There are seven prominent culminating points in the relief of North America, each one of which can be used as a type of the physical features of all the others. Again, if we divide these seven elevated districts into two sets, we shall discover a still more striking parallelism between the individual members of each group. But the most remarkable revelation is the fact that each one of these points is more or less closely the centre of an area of economically important mineral resources. It is interesting to note in this connection that six of these mineral tracts lie mainly within the borders of the United States, three of them being almost wholly in our territory. For

Jan 1, 1883