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By Om P. Garg

The purpose of this paper is: 1) To summarize the capabilities and some of the limitations of the existing mine planning software. 2) To provide some guidelines for acquiring the software. 3) To identify problems and challenges in terms of how to justify increased use of computers (particularly the 32-bit microprocessor based super micro computers), for various activities related to a mining operation No attempt has been made to review the contents of available software packages in detail. Also the scope of this paper is limited to mine planning related computer applications. Applications related to accounting, inventory control, preventive maintenance, equipment scheduling, etc. have not been covered.

Jan 1, 1983

By Inoka E. Perera, Michael J. Sapko, Marcia L. Harris

Experiments conducted with limestone dusts and dolomitic marble dusts have indicated that when rock dust is wetted and subsequently dried, it becomes a solid, non-dispersible cake. However, in order to be effectively inert a coal dust explosion, rock dust must be able to disperse as individual particles to air. To counteract this, rock dust manufacturers created treated rock dusts that will resist caking after moisture exposure. National Institute for Occupational Safety and Health (NIOSH) researchers conducted a series of laboratory-scale experiments on four base rock dusts and their treated counterparts to assess the effectiveness of various anticaking additives after being exposed tomoisture and then dried. The dusts were exposed tomoisture using humidity cabinets having a high relative humidity (99% RH) and by also exposing the rock dust bed to water through bottom wicking. The dusts were then evaluated for dispersibility after drying using the NIOSH-designed dust dispersion chamber. The anti-caking additives were different concentrations of stearic acid, oleic acid, and xylene-based surfactants. All results were compared to a reference rock dust used to conduct large-scale experiments in the Lake Lynn Experimental Mine (LLEM), Fairchance, PA. When the untreated dusts were dried after exposure to moisture for 1 day, no dispersion was measured. However, rock dusts treated with anti-caking agents were readily dispersible even after exposure to moisture for 6 months. This report details the analysis and characterization of anticaking additives using the NIOSH-designed dispersion chamber and the 20-L explosion test chamber.

Apr 12, 2021

By T. McWaters

In 1911, Miami Copper Co. began a block caving operation at its Miami, AZ property. A gravity mill was used to separate copper minerals from the Pinal Schist host rock. Until 1932, the mill tailings were deposited by the upstream method using perimeter launders and spigot valves in six canyons adjacent to the mill. In 1928, the larger and more distant Solitude tailing pile was developed. By 1932, it was receiving all tailings. In 1925, Miami Copper converted the gravity mill to flotation with sulfide copper recoveries. From 1934 to 1943, Miami, Copper ran a leach-precipitate float (LPF) circuit on mined ore and, in 1943, began sulfuric acid in-place leaching of a portion of the caved area formed by block caving. The pregnant solutions were collected underground and pumped to the LPF precipitating drums to harvest copper. In 1954, the company started mining low-grade ore. This led to the running an old LPF plant on select mill tailings from April 1957 to March 1959. In 1959, block-cave mining ceased. Solution mining became the only source of production using a launder precipitation plant. In the mid-1960s, Miami Copper merged with the Tennessee Corp. In the latter part of the decade, Cities Service Co. bought the combined properties. In 1976, Cities Service commissioned a 15-t/d (16.5-stpd) solvent extraction electrowinning(SX-EW) facility at its Miami copper property to replace the precipitation plant. In 1982, Occidental Petroleum Co. bought Cities Service. In 1983, the Miami operations were sold to Newmont Mining Corp. and set up as a subsidiary company, Pinto Valley Copper Corp. Finally, in 1987, Newmont Mining spun off a combined Pinto Valley and San Manuel unit as Magma Copper Co.

Jan 1, 1990

By M. Adnan Goksel

The hydrothermal agglomerating process described (U.S. Pat. 3,235,371, (1966)) is different from the conventional high temperature processes. Green pellets or briquettes made with mixtures of moist iron ore concentrates and burned or hydrated lime fines are hardened in an autoclave at 198°C and under steam pressure for 1/2 to 5 hours, with or without previous drying. Under the neutral conditions, oxidation of magnetite does not occur as in the conventional processes. The resulting agglomerates are hard and resistant to abrasion and weathering, and they do not disintegrate in the Linder test. The equipment required for the process is not complicated, and favorable operating costs are projected because of the low temperature and efficient heat recuperation. A low capital investment makes the process attractive even when the annual pellet production is below a million tons.

Jan 1, 1968

By CORA ROELOFS

While the COVID-19 pandemic has dominated the headlines, another epidemic in the United States has continued apace — the opioid epidemic. Half a million opioid overdose deaths have occurred in the United States since 1999, when the opioid epidemic began. The causes of the epidemic include the rise in prescriptions for opioid pain medications, including for work-related pain. Miners and other occupations identified as physically demanding and at higher injury risk have been found to be at increased risk for opioid overdose [1]. However, awareness of the risk factors that might lead to opioid use, the potential hazards associated with their use, and resources to prevent addiction and death can allow miners to make choices that can reduce these risks.

By Henry J. Jacoby

This report concerns Contract No. 3B of the Port Richmond Project, for the Department of Water Resources of the City of New York. It involves the construction of 7, 000 ft. of 7 ft. finish I. D. interceptor sewer by tunneling in soft ground, as well as associated manholes, regulator chambers, siphons and miscellaneous sewers and structures, beneath a heavily travelled perimeter road in Staten Island. The Contractor is Richmond Constructors, a joint venture of Grow Tunneling Corp., sponsor, MacLean Grove & Company, Incorporated, Morrison-Knudsen Company, Inc., and Andrew Catapano Co., Inc. Project manager is Paul DeMarco, Vice-President of Grow Tunneling Corp. The cortract, as designed and bid, requires the use of liner plates 101 -0" O. D., and both cast iron and steel designs of several widths were included in the bid documents by the owner. The specifications also required the contractor to install and put into operating condition, prior to commencement of mining, a complete low pressure compressed air plant and all accessories for mining in compressed air, even though the contractor was given the option of using other methods of ground water control. A third requirement of the specifications was that a shield be used, either manual or mechanical, and with full provision for "breasting". BACKGROUND The first soft ground shield driven tunnel in the United States was in New York City and was built under Broadway in lower Manhattan in 1869

Jan 1, 1974

By V. L. Andrade, K. L. C. Goncalves, N. A. Santos

This paper describes results obtained in a test program performed with new equipment, called Mini Pilot Plant, manufactured by Canadian Process Technologies. This equipment was acquired by CVRD aiming at testing flotation circuits, in a continuous closed configuration, with samples obtained from drill cores. Success of this goal would allow CVRD to establish the metallurgical performance of mineral deposits with more confidence in comparison to Locked Cycle Tests (LCT). This paper discusses the importance of assessing the ore variability and compares results obtained in LCTs and Mini Pilot Plant. Results suggest that more reliable data is obtained in MPP test.

Jan 1, 2002

By A. K. Bakshi

Slurry rheology affects autogenous grinding performance by changing the rock's breakage characteristics. In this study pilot scale batch autogenous grinding was carried out to observe the effect of viscosity on the breakage characteristics of the rocks (the media), and on the overall specific energy consumption. Clay/fines content, and temperature of the initial charge, were varied to alter the viscosity of the slurry. Results showed that at higher slurry viscosity, rocks became more difficult to break, resulting in an overall increase in the specific energy consumption of the mill. Also, it was observed that viscosity had a significant effect on the amount of critical size material present in the grinding circuit, where the critical size material is the material which is too large to be effectively ground in the mill, and too fine to act as grinding media.

Jan 1, 1996

By Felipe Calizaya, Sekhar Bhattacharyya

Noise-induced hearing loss (NIHL) is prevalent in mechanized underground mines. Federal regulations are often not complied with effectively. Miners are also prone to ignoring administrative guidelines and/or personal protective equipment for hearing conservation. As a result, quality of life among experienced miners plummets while occupational risks increase at workplaces. This research focused on auxiliary fans used in underground mines. These fans work at high rotational speed and generate extremely high levels of noise in close proximity to miners. Silencers used are often of little effect due to poor maintenance. A new silencer is tried in the laboratory with the objective of easy maintenance and resulting reduction of noise exposure for miners.

By Elnaz Saminfar, Jae Bateman, Eric Westergren, Mark Trim

This paper presents a case study of two major Australian infrastructure projects that used digital engineering to facilitate design delivery: WestConnex Project (Rozelle Interchange), and Sydney Metro West (Eastern Tunnelling Package). The paper presents project overviews and building information modeling (BIM) execution and focuses on modeling techniques, software utilization, data management strategies and how the digital models helped the design-build team mitigate impacts to schedule by identifying clashes between disciplines before the execution of work. Finally, it demonstrates the positive and transformative impact of digital engineering on the design and construction of large underground infrastructure projects and highlights its role in asset management throughout the project lifecycle.

Jun 23, 2024

By Ulrich Maidl, Gustavo Aguiar, Argemiro Ferreira, Marco A. Peixoto Silva, Marc Comulada

"Metro Line 5 in Sao Paulo is being constructed. This lot extends for 4,940 m with twin EPB shield tunnels under a dense and busy urban area, with an excavation diameter of 6.9 m. The tunnels run predominantly in the tertiary soils of Sao Paulo where extensive experience exists from previous EPB shield tunnel projects. However, new experience is being gained in Sao Paulo in shield tunnelling through Saprolite, the weathered product of the underlying Gneiss crystalline basement, through the resulting residual soils and in rock-soil mixed face conditions. Furthermore, experiences in difficult mixed face soil conditions with overconsolidated clay at the face in combination with loose sands at the crown under the groundwater table will be presented. Additionally, the design, operational and controlling approach followed for the shield drive at particular critical cross-sections where the shields were driven close or under buildings. INTRODUCTION Within the framework of Sao Paulo´s metro network expansion, the excavation of the shield tunnels for Metro Sao Paulo Line 5 is currently taking place. The present paper deals with the description of the most relevant features from the construction of the Line 5 – Lot 3 tunnels. The paper presents how particular challenges were dealt maximising potential of EPB shield tunnelling technology. Challenges were posed not only by the difficult boundary conditions of urban shield tunnelling, such as shield drive under buildings, but also by complex geotechnical situations. PROJECT DESCRIPTION The great urban area of São Paulo is one of the biggest cities in the world, with around 20 Million people living in the city and in the suburb area. The city faces great mobility problems and in the last years the government has been investing great amounts on the megacity´s metro expansion. The Line 5 Extension plays an important role to connect the south area to the central area of the city, with a whole extension of 11 kilometres, including 11 new stations. It is estimated that this line will transport almost 900.000 passengers/day. The first stretch of the expansion, Lot 3, consists of two single tunnels, almost 5 kilometres long each, crossing 4 stations. Figure 1 shows details of the Line 5 Expansion."

Jan 1, 2016

By David A. Summers, Clark R. Barker

INTRODUCTION The use of high pressure water as a means of excavating valuable mineral from the earth dates back many hundreds of years, but is most familiar through its use in sluicing the gold bearing deposits of California and Alaska. Interestingly, that practice, which dates back from at least 1852, is now nearly defunct with only one known surviving hydraulicking operation.(l) In that particular development water under a relatively low, natural pressure head is carried to a nozzle and from the nozzle it is thrown a distance of perhaps 20 ft to wash the gold bearing material down into a channel from whence it's carried over some mineral collector, and the water is then recirculated. Development of this practice in coal mining began in Russia in 1915, and Dr. Muchnik established the criteria for hydraulic mining during the 1930's. The first water jet mine was established underground in 1939 and has been followed by several larger mines to the present day where there are at least 11 large mines producing about 10 million tons of coal per year in the Soviet Union.(2) Water jet mining has expanded from Russia through Japan, Germany, Poland, Czekoslovakia, and mainland China. The nearest location to the United States is currently at the Kaiser Mine in Sparwood, British Columbia, where a three-man crew has mined up to 3,400 tons of coal in a 6-hr shift. There are many advantages to this particular operation. It is one of the safest mining operations for coal in Canada and has won safety awards because of this. The process is relatively cheap since the cost of the equipment is much lower than that which would be required conventionally using either longwall or shortwall mining, and transportation is achieved by fluming the coal to a central station using a gravity feed and then pumping to the surface, (3) For this

Jan 1, 1976

By W. M. Cross

The use of fillers and reinforcements for plastics has increased considerably over the past few decades. For example, in the 1980's the average growth rate of filler use was 5.8%. [Katz and Milewski, 1987] Similar filler use growth rates occurred in the 1970's due largely to the increase in price of petrochemical starting materials for plastics. While filler use is still sometimes predicated on the cost benefits associated with their addition to the plastic, other mechanical and performance advantages associated with filler addition are being realized, and account for most of the increased usage. Plastic filler types are many and varied, and include both inorganic minerals/metals and organic compounds, with the former type being, by far, the more common. Common mineral fillers include oxides, including both natural and synthetic silica; carbonates, particularly calcium carbonate; clays such as kaolin; and silicates like mica and talc. It has been recognized that a number of factors influence filler performance, including particle size, shape, surface area, and hardness to name a few. In addition, the interaction between the filler and the plastic is of paramount importance as this interaction will determine the wettability, bonding and the adhesion between the two materials, and ultimately, the mechanical properties of the composite. Froth flotation has long been recognized as a viable process to separate different mineral types. [Leja, 1982] Prior to flotation the minerals are liberated from the ore by comminution. The mineral particle size range produced by this comminution process is typically between 300 and 10 microns. This size range is also typical of mineral fillers for plastics. The size similarity between mineral fillers and minerals concentrated by froth flotation is only one of many similarities that can be found.

Jan 1, 1997

By Craig Allan

Underground construction environments, especially those with limited airflow such as shafts, cross passages, and stations, necessitate effective dust control. This requires combining existing measures with adapted approaches for more efficient and productive operations, cleaner jobsites, and decreased worker exposure to contaminated air. This paper will discuss new configurations and trends in dust collection on Australasian infrastructure projects including WestConnex, Melbourne Metro Tunnel and City Rail Link, all of which have applied innovative methodologies for mobile at-source dust collection. Mobile dust collectors can be track-mounted dust collectors operate alongside equipment, use hydraulic stepping systems to advance with roadheaders, or compact castor-mounted units are used within cross passage confines.

Dec 1, 2022

By J. A. Barrera-Godinez

Traditional batch flotation tests produce a limited number of data points from which to evaluate the kinetics of the process. In this research, continuous weighing of froth, from a modified circular flotation cell, using a computer/data acquisition system., has been coupled with chemical analyses from intermittent froth sampling. This combination has permitted the experimental data to be smoothed such that the flotation kinetic parameters could be determined with enhanced confidence. To demonstrate the procedure, a galena ore was floated to permit flotation kinetics to be investigated as a function of cell parameters. It was shown that the kinetic data of this lead flotation most closely correlated with the Huber-Panu three parameter model. In addition the results illustrated the effect of froth thickness, froth scraper rate and air flow rate on the cell performance, in terms of mass flow, grade and recovery.

Jan 1, 1990

By L. P. Johnson

Longwall mining has gained acceptance as a safe method of maintaining coal production where conventional systems were unsuccessful or uneconomic due to bad roof conditions (Kuti8). One of the major problems confronting American operators involves the correct choice of equipment which should be selected to suit the local mining and geologic conditions for optimum productivity. To achieve this, factors such as rock strengths, local geology, panel geometry, and panel orientation must be examined to optimize production and minimize down time due to ground control problems. Little quantitative information is available in the literature regarding the effects of geologic conditions on American longwall operations, and past implementations of longwall systems appear to have been based largely on experience. When mining engineers are able to assess the geologic conditions both quantitatively and qualitatively, they can more fully optimize equipment selection and panel design.

Jan 1, 1977

By Taner Aydogmus

The A$29 billion Chevron-operated Wheatstone Project is one of Australia’s largest resource projects. Located at Ashburton North, 12 kilometers west of Onslow in Western Australia, the project will consist of two Liquefied Natural Gas (LNG) trains with a combined capacity of 8.9 million tons per annum and a domestic gas plant. The LNG Plant will serve the offshore gas fields, which are situated some 250 km off the coast of Onslow in Western Australia. Once operational and on-stream, the Wheatstone Project will contribute to Australia becoming the world’s second largest exporter of LNG. For crossing the environmentally sensitive shore area, a micro-tunnel with an internal diameter of 2 m and approx. 1,242 m in length has been constructed by means of the pipe-jacking method. The micro-tunnel will accommodate a 1.1 m diameter pipeline (trunkline) to deliver gas from the offshore fields LNG Plant. The Wheatstone shore crossing design involves a number of unique challenges owing to its coastal location, where the alignment crosses through a shore area and terminates in a marine environment. This paper provides an overview of the Wheatstone Shore Crossing Project, presents the key features, and discusses the main aspects of the micro-tunneling design.

Jun 13, 2021

By James Paone

Drillability of rocks by mechanical means is closely related to the physical properties of the respective rocks, Various approaches by previous investigators on rock drillability are presented, as well as recent techniques studied by the Bureau of Mines. The studies show drillability concepts based on (1) theoretical drilling equations derived from laboratory drilling experiments extended to field drilling results and on (2) a statistical method where multiple regression analysis is used to develop a prediction equation for drillability.

Jan 1, 1966

Controlled blasting experiments in small development drifts were conducted at CANMET's Experimental Mine, from August 1992 to November 1993. The objective of these experiments was to develop suitable controlled blasting techniques for small development headings drilled by jackleg with 32 mm diameter holes. The experimentation also aimed to provide insight into blast damage mechanisms. Particular attention was given to the physical-mechanical properties of the rock and the rockmass structural data in order to make the results applicable to other geological environments. The drift faces were approximately 2.4 m by 2.4 m with 36 to 43 holes drilled to a depth of 2.4 m. Cartridged water gels, emulsions and semigelatin dynamite were used in the cuts and as primers, ANFO as the main explosive and decoupled 19 mm diameter semigelatin dynamite charges were used in the perimeter holes. Smooth blasting techniques and pre-splitting were tested in the underground mine. All the blasts were monitored with a multi-channel blast vibration monitor to which was attached sets of high frequency geophones and accelerometers. This first set of experiments has illustrated the efficiency of con-trolled blasting techniques to reduce blast damage and demonstrated the need for further research to improve the safe and efficient use of explosives.

Jan 1, 1995

By G. E. McClelland

Introduction Many discoveries have been made during the-past decade of low grade gold-silver deposits in the western US. This has stimulated development of low cost cyanidation procedures for precious metal extraction. Heap leach cyanidation techniques possess considerable potential for application to these low grade ores, small ore bodies, mine strip waste, and tailing materials where fine grinding is not necessary for good extraction. For heap leaching to be successful, these resources must have good permeability to achieve uniform distribution of the cyanide solution throughout the heaps. Some of the most difficult of the gold and silver ores to treat successfully by heap leaching are those containing excessive amounts of clays, or fines generated by crushing. Presence of excessive amounts of slimes, -50 µm (-270 mesh), in the heap leach feed will slow percolation, cause channeling, or produce dormant or unleached areas within the heap. This may result in unreasonably long leaching periods and poor extractions. In extreme cases, the clays or slimes can completely seal the ore heap. This causes the leach solution to run off the sides of the heap rather than penetrate the ore bed. The problem of heap leaching ores with fines can be aggravated while preparing ore heaps because of the natural sorting of coarse and fine material that occurs. This phenomenon results in concentration or ore fines in the center of individual ore piles and concentration of larger rock fragments of the lower slopes and base of the pile. When the individual piles within the heap are leveled off for the installation of the sprinkling system, additional segregation occurs as the fines sift through the coarser ore particles. This results in localized areas or zones with marked differences in permeability. Consequently, the leach solutions follow the course of least resistance. They percolate down through the coarse ore regions and bypass or barely wet areas that contain large amounts of fines or slimes. Effective use of marginal gold and silver resources by heap leaching required development of new methods to achieve more uniform size distribution when preparing ore heaps and better slime control during leaching. Early methods Agglomeration and balling of crushed ore to produce a porous and more uniform feed material for heap leaching is a viable method for treating clayey ores. Researchers from the US Bureau of Mines in Reno, NV began agglomeration pretreatment research in the mid-1970s for applications to and exploitation of these poor percolating feed materials. Little attention had been given to such methods before the Bureau's research. In 1905, T. C. Scrutton developed a unique technique for obtaining rapid vat leaching of a clayey ore where the gold was finely disseminated. His technique consisted of rolling the ore down a chute inclined at 60° to form agglomerates or balls readily permeable by the cyanide solution. However, these agglomerates lacked rigidity. And, to ensure good percolation leaching and washing, they could not be bedded in layers more than 1 m (3 ft) deep. If this depth was exceeded, it is difficult to obtain uniform leaching and washing. This results in reduced gold recovery. Shepard and others in 1937 studied the addition of lime and carbon dioxide or calcium carbonate to gold-bearing tailings to form agglomerates suitable for vat leaching. Satisfactory percolation flow rates were achieved in 90 g (3 oz) scale experiments, but the reagent requirements were cost prohibitive. Agglomeration and pelletizing has been used in other segments of the mineral industry. This technique was first used successfully around 1911 for pelletizing iron ores. Since then, agglomeration

Jan 7, 1986