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By A. J. S. Spearing, B. Forbes, T. Kostecki, A. Hyett

Improving upon the past understanding of the interaction between installed rock bolts, the immediate roof and sidewalls is vital for the implementation of sound support system design, as this has a direct impact on rock-related safety. This is the primary goal in rock-bolt-related research. The earliest research in this field concentrated on limited laboratory and in situ measurements accompanied by theoretical analyses, based on the Kirsch equations. This represented the initial insight into understanding relative ground movements and their impact on primary support. However, these studies were far from complete. More recently, major technological advances in computing power within the mining industry has changed the scope from theoretical analysis to computer simulation. Even with these advancements our understanding of rock bolts in situ and in the laboratory has not progressed, particularly concerning bending and shear. To measure the behavior of rock bolts, the widely accepted practice is to populate the bolts with an array of strain gauges. Historically, resistive foil strain gauges or long displacement sensors have been used. Additionally, all instrumented rock bolts have used only two diametrically opposed slots. Rock bolts instrumented with these methods have significant shortcomings, one of which is the inability to capture shear and bending. The shearing and bending of rock bolts are particularly common in tabular soft rock mining, such as coal mining. This paper discusses the use of three slotted rock bolts, cut diametrically 120º apart, and two new optical fiber technologies populated along the entire rock-bolt length.

Jan 1, 2015

By A. Newman, M. Goycoolea

"In this paper, we consider an underground production scheduling problem consisting of determining the proper time interval or intervals in which to complete each mining activity so as to maximize a mine’s discounted value while adhering to precedence, activity durations, and production and processing limits. We present two different integer programming formulations for modeling this optimization problem. Both formulations possess a resource-constrained project scheduling problem structure. The first formulation uses a fine time discretization and is better suited for tactical mine scheduling applications. The second formulation, which uses a coarser time discretization, is better suited for strategic scheduling applications. We illustrate the strengths and weaknesses of each formulation with examples.IntroductionProject scheduling is an important aspect of underground mine planning that consists of determining the start dates for a given set of activities so as to maximize the value of a project while adhering to operational and re-source-availability constraints. Important activities that require scheduling include development, drilling, stoping and other ore-extraction techniques, and backfilling. Precedence relation-ships impose an order in which activities can be carried out based on their location in the mine: for example, the activity a associated with development of an area must be completed before the activity a´ associated with extraction of that same area can begin. Re-sources include attributes of the mining operation, such as the amount of extraction and mill capacity available per time period, and are determined by capital and equipment availability and other factors. In this paper, for our set-ting, resource-availability constraints consider the amounts of material that can be extracted and sent to the mill — that is, processed — per time period."

Mar 1, 2017

By Bill York-Feirn

The Colorado Mine Safety & Training Program (MSTP), in late 2005, completed and began distributing two new training tools; one geared to underground coal mine foremen and the other to surface aggregate employees. Through strong partnerships with MSHA, Colorado Coal Mine Board of Examiners, Colorado Mining Association and the Colorado Rock Products Association, the MSTP continues to create innovative and interactive training tools for not only Colorado, but for the national mining community. "Although we shoot and produce these materials in Colorado, it's important to us to make sure they are useful nationally," said Bill York-Feirn, MS TP Manager. The interactive DVD program "Underground Mine Foreman Certification Study Guide (Coal)," was completed in October 2005. It won the 2005 Grand Prize at the MSHA National Training Materials Competition in Beaver, West Virginia. [ ] This program is fully based upon the requirements of Title 30 Code of Federal Regulations (30 CFR) Parts 48, 50, 70 and 75 for underground coal mine foremen. It contains eight modules plus immediate access to relevant laws in the appendix. Topics covered include: Federal Law, Practical Math Skills, Mine Gases, Ventilation Maps, and scenarios addressing a variety of practical mining concerns. The DVD is designed for self-¬paced study and practice.

Jan 1, 2006

By J. Szarkowski

"INTRODUCTION The Butte district of Montana is well-known as one of the biggest historic producers of copper in the world. It is also a classic example of a porphyry Cu-Mo system that has been overprinted by zoned, polymetallic (Cu-Zn-Pb-Ag) lode mineralization. After copper, silver was the next most important metal mined from Butte, with over 700 million ounces of total Ag production between 1880 and the present day. Although many papers have been written on the mineralogy of the early porphyry Cu-Mo mineralization and the high-grade Cu-rich lodes in the center of the district, relatively little information exists on the mineralogy of silver in Butte. The purpose of this paper is to summarize past and present silver production trends for the district, and to combine previously published work with new research to examine the mineralogy of silver in the Butte mining district. BUTTE HISTORIC SILVER PRODUCTION According to a recent USGS compilation1, Butte is one of the most Ag-rich porphyry deposits in the world, both in terms of average Ag grade (8.6 g/ton) and total production + reserves (Fig. 1). It is also the 2nd biggest Ag-producing mining district in the U.S. (after the Couer d’Alene district, Idaho). Annual silver and copper production data for the Butte district, compiled from various sources2,3,4, are summarized in Figure 2. Peak production of Ag and Cu was in 1917. While Ag production gradually declined in the ensuing decades, Cu production remained strong until the years leading up to the closure of the Berkeley Pit in 1982. In 1984, mining of the nearby Continental Pit resumed under a different operator, and continues to the present day. The Continental mine produced an average of 35,000 metric tons Cu and 575,000 oz Ag per year between 1984 and 20044. These figures do not take into account a period of mine closure in 2001-2003 due to an unexpected hike in utility prices. The long-term decline in Ag/Cu ratio of ore mined in Butte (Figure 3) is due to several factors, including: 1) changes in metal prices; 2) a downwards decrease in Ag/Cu ratio of most of the lodes with depth below surface; and 3) a shift in mining methods from selective underground mining of high-grade veins to open-pit mining of the bulk rock."

Jan 1, 2016

By W. H. Jay, F. Lawson, D. F. A. Koch

Ion exchange resins may in the future displace activated carbon in gold plants where cyanidation is practiced. Recently patented technology based on interpenetrated polyurethane polymers shows that these new materials offer significantly improved loading kinetics over both activated carbon and commercially available ion exchange resins. These polymers are not restricted either in particle size or in density and therefore offer the gold industry the potential for a further technological advancement.

Jan 1, 1995

By José Adilson de Castro

In this paper a new technology for a compact iron ore sintering machine is analyzed. The compact sintering process is based on the massive injection of gaseous fuels and the solid fuel is only agglomerated fine charcoal obtained by biomass. The solid fuel used in this study is obtained by agglomeration of fine charcoal produced from elephant glass which has very short period for production and CO2 capture(less than 6 months in tropical climate). To overcome the lower heat supply into the combustion front of the sintering process the simultaneous injection of oxygen and gaseous fuel is proposed. The proposed methodology is to combine the solid fuel (agglomerated fines charcoal) and steelworks gases in a compact machine to enhance heat and mass transfer with high productivity (about 5 times the conventional large machine). A multiphase mathematical model based on transport equations of momentum, energy and chemical species coupled with chemical reaction rates and phase transformations is used to analyze the inner process parameters. A base case representing a possible actual industrial operation of the sintering machine is used in order to compare different scenarios of practicable operations which represents advanced operations techniques. The model was used to predict six cases of combined operation with biomass and fuel gas utilization with oxygen support.

Aug 2, 2018

By Peter Van deVelde

Many companies in North America because of economic or environmental reasons are considering reprocessing material from their waste ponds. The Japanese have developed highly specialized machines and techniques to reprocess industrial/mining wastes from settling ponds. This paper discusses the techniques and results of applying this technology to North American applications.

Jan 1, 1983

Section 67 Department of Conservation and Development, State of New Jersey, State House Annex, Trenton, N. J. H B Kummel, State Geologist For lists of publications, maps and geologic folios, address the above. Where price of postage is noted, in the following list of available publications on geology, the postage is only to New Jersey and

Jan 1, 1933

New Jersey Zinc Co. - The Mines Franklin-Sterling Friedensville Development Austinville Ivanhoe Development Eagle Mine Hanover

Jan 12, 1953

New Jersey Zinc Co. - The Plants Canon City Palmerton Depue

Jan 12, 1953

By I. Martinez-Dominguez

In September 1992, mining in Mexico was opened again to foreign investment by President Salinas-de Gortari, after thirty years of "Mexicanization" of mining industry which limited foreign participation up to a 49 % (or 34 % in case of national reserves) on a Mexican mining corporation. During said period mining in Mexico was controlled by four or five big mining companies and besides mining production was focused mainly on silver, lead, zinc, copper and fluorspar. Suddenly in middle of a big crisis on Mexican mining industry due to low prices of minerals in the world and also in a period on which it seems that mining industry in the United States and Canada has been condemned to die for environmental reasons, it appears a new Mexican Mining Law to permit foreigners to participate in mining in Mexico' trough Mexican mining corporations that they may control up to 100 %

Jan 1, 1994

By Michael Prince

"Managing slurry is a constant challenge for mining operations. Since slurries are not uniform, the challenge is complicated by varying rheology, velocity, temperature and pressure, all of which affect how the slurry moves through the pipeline and how destructive it is to the system it is flowing through. Picking the right equipment from the outset — the right size pipe, the right size pump and the proper valves for the application — allows mines to operate more efficiently. Better valve designs deliver multiple benefits — they can lower the cost of operations, reduce the amount of maintenance and associated downtime required and are better for the environment. Historically, modulating systems have used ball, plug and pinch valves to manage the flow of slurry, but each of these alternatives has limitations. Ball valves require ceramic lining in order to delay wear, and once a ball valve does wear, the entire valve must be replaced. Similarly, plugs in plug valves should be coated to perform in control systems, and whole valves must be swapped out upon wear. Pinch valves are expensive and only require replacement of the sleeve. However, sleeve replacement involves an extremely arduous process in which the valve is completely taken apart.Traditionally, designers have avoided using knife gate valves (KGV) in modulating systems because KGVs have not been able to hold up under the harsh operating conditions. The throttling that is required in some of these processes rapidly fatigues conventional KGVs, rendering them useless and in need of replacement. Fortunately, innovative design changes have the potential to change established views.Breaking new groundRecognizing the need for improved components, Victaulic took on the challenge of designing a valve that could withstand abrasive slurry systems for a much longer period of time. The first step in this process was to talk to miners, maintenance personnel, process engineers and operators in the field about the limitations of current offerings and then determine design specifications for an ideal replacement.Many of the responses to these inquiries were very similar and reflected challenges with current operations; the primary objective was to find a valve that would be lighter and cheaper than the valves currently in use. In theory, a lighter valve would be easier to replace, and since replacements need to be performed frequently, a cheaper valve seemed like the right idea."

Feb 1, 2019

By Somchet Vongpaisal

This paper presents the R&D results on the development of a new knowledge-based system for predicting stope instability and associated unplanned dilution in deep underground mining operations. A new prototype was developed based on databases generated from 3D non-linear elasto-plastic finite element stress analysis, heuristic rules, and case histories. This prototype aims to assist mine operators to make decisions on strategic mine planning and feasibility in a quick and efficient manner thereby minimizing risk on ground failure and optimizing mining costs.

Jun 1, 2012

By C. V. Deutsch, O. Babak

A longstanding problem in geostatistics is that kriging usually assigns significantly greater weights to end samples in strings of data than it does to central samples. These weights are theoretically valid, but suboptimal estimates may result when there are geological trends in the variable near contacts, that is, large weights may be applied to samples that are systematically lower or higher than average. A number of ad-hoc corrections exist, each with pros and cons; none are fully automatic with a well-defined measure of optimality. A new method for estimation in a finite domain is proposed. This method is referred to as finite domain kriging. The method is based on kriging with a successively larger number of data. The total number of relevant data (n) is established, and then n kriging matrices are solved. The first matrix has the closest single data value (n-1 weights are set to zero); the second has the two closest data (n-2 weights are set to zero) and so on. The final matrix has all n data. The kriging weights used for estimation are the average of the weights from the n successive kriging runs. Each kriging run is optimal, yet with different smoothing and a different treatment of data at the end of the strings. The result is a set of weights that does not give undue influence to data values at the end of strings. The methodology is developed with examples. Cross validation shows that finite domain kriging outperforms conventional kriging.

Jan 1, 2009

By Z. T. Bieniawski, E. Unal, H. Reginald Hardy

INTRODUCTION Rock bolts are a major means of support in underground coal mines in the United States. However, two of the most crucial problems facing the mining engineer today are that of finding a well defined and standard method for testing the anchoring ability of rock bolts, and of selecting the most suitable type of rock bolt and bolting pattern for a particular mine or specific mine section (Anon., 1982). Such selection requires not only an understanding of the behavior of the rock mass and the rock-bolt unit itself, but also a knowledge of the basic mechanisms by which rock bolts provide support while they interact with the rock mass during various field loading conditions. A recent study in this area has shown the inadequacy of present methods used in selecting and testing of rock bolts and the lack of clearly defined guidelines for safe and economical design of bolting patterns (Bieniawski, et al., 1980). The present paper describes a research study aimed at developing laboratory instrumentation and associated techniques for the evaluation of bolt-rock interaction. The instrumentation system developed, procedures followed during various experiments, and typical results from a series of studies carried out on mechanical bolts are presented. DEVELOPMENT OF THE ROCK BOLT TESTING FACILITY General A block diagram of the experimental facilities are shown in Fig. 1. The system consists of three main sections. The first

Jan 1, 1982

By Keith A. Heasley

In the past, numerous displacement-discontinuity (DD) models of stratified rock masses have been proposed using a homogeneous isotropic elastic overburden. In this paper, it is postulated that a laminated overburden model might be more accurate for describing the displacements and stress in these stratified deposits. In order to investigate the utility of using a laminated overburden in a DD model, the fundamental mathematical basis of the laminated model is presented and graphically compared with the fundamental behavior of homogeneous isotropic elastic overburden and with field data. Specifically, the stresses and displacements surrounding an idealized longwall panel as determined from the laminated overburden model are presented and compared with results from the homogeneous isotropic overburden and with measured abutment stress data. Also, the remote displacements and surface subsidence as calculated by the laminated overburden model are compared with homogeneous isotropic calculations and with measured subsidence data. The results of this investigation show that the laminated overburden is more supple, apt to propagate displacements and stress further, and better able to fit observed data than the classic homogeneous isotropic overburden. Ultimately, it is suggested that the laminated model has the potential to increase the accuracy of displacement and stress calculations for a variety of mining situations.

Jan 1, 1996

By Rudolf Hubmer

In October 2013 JSW Steel decided to place an order to Primetals Technologies Austria (former Siemens VAI Metals Technologies) for the installation of a comprehensive Level 2 process optimization system for more than 20 existing production facilities of various suppliers. For SMS-I new L2 systems are provided for two hot metal pretreatment stations, three hot metal desulphurization stations, three ladle furnaces, two 1-strand slab casters, a ladle tracking system as well as a shop supervisory system. Additionally the existing L2 system for one 1-strand slab caster is being upgraded in the course of the project. In SMS-II new L2 systems for the 7 hot metal desulphurization stations, 4 ladle furnaces, 1 new RH vacuum degasser, ladle tracking system and a shop supervisory system are supplied. Despite of the challenging time schedule the commissioning of the single facilities started within less than 12 month after contract effectiveness. The installed Level 2 process optimization systems together with the achieved results are described in this paper.

Aug 16, 2017

By D C. Ford

The Argyle AK1 orebody was discovered in 1979 and subsequently found to be a large, economically viable reserve with high grade diamondiferous ore. Production began via an open pit operation at the end of 1985 and has continued for some 25 years to present day. This, however, will come to an end in the next few years with production moving to an underground operation via block-cave mining methods.A series of studies from 2001 - 2005 was carried out; diamond drilling commenced after approval in 2006, from an exploration drive to determine the likelihood of the current proposed block cave operation.In 2006, development of the block cave project began, in order to realise the part of the orebody below the extent of the open pit mining operation.Development of the block cave technique, comprising an undercut level beneath the target zone of the orebody with subsequent extraction level 15 - 20 m beneath, relies largely on a number of block-caving parameters (hydraulic radius, rock type, structure and orientation of stress and grade of the orebody). These all have an influence on cave ability and eventual profit of the operation. Evaluation of further potential for taking this orebody beyond the block cave phase with options such as sublevel-caving are being considered for the UG-2 portion of the resource/reserve. Diamond drilling for this work is currently under revise.The challenges faced in transitioning form the surface operations to the underground, comprising a changing workforce, converging development drives, underground aquifers, major excavations and transportation of ore via automation are intriguing.

Aug 22, 2011

By H. Staton, N. Michaelson

"INTRODUCTION Lundin Mining’s Eagle Operation, located in Marquette County, upper Michigan consists of a mine and concentrator that process a Ni-Cu-(PGE) ore. The mine itself is an underground operation and the ore is trucked from the Eagle mine site 66 miles to the Humboldt mill where both nickel and copper concentrates are produced. Operations began in 2014 and continued with an average production of approximately 23,000 tonnes of Ni and 20,000 tonnes of Cu per year for the first three years of operation. The Humboldt Mill, currently operated by Lundin Mining, processes the nickel/copper ore from Eagle Mine and performs the concentration through several stages of flotation. Originally built in 1954, the Humboldt Mill began operations as an Iron Ore processing facility, and was converted to a gold processing plant during the 1980s. Various groups owned the site after closure of the gold operation. Eagle purchased the Mill in 2008 and invested more than $280 million to clean up historic mine waste and refurbish the plant (see flowsheet in APPENDIX). This paper will overview the ramp-up of the operation, and discuss some specific areas that went well and some that could have gone better during the design phase. HIGH LEVEL DESIGN CRITERIA Coarse ore arrives from the mine and is stored in a building with a capacity of 10,000 tonnes. Ore is crushed in three stages to a final product size of 100% Passing 12mm. Crushed ore is conveyed to the mass flow fine ore bins, which have a live capacity of 3000 tonnes. Crushed ore is fed to two parallel 900 HP ball mills, charged with 3” high chrome grinding media, and ground, in closed circuit with hydrocyclones, to a p80 of 110 microns in the flotation feed. Soda ash is added to the mills based on process water hardness. Cyclone overflow passes to the bulk conditioner where Sodium Isopropyl Xanthate (SIPX) and Methyl Isobutyl Carbinol (MIBC) are added. The slurry is pumped to the rougher bank for bulk flotation. Rougher concentrate is fed to a 500HP vertically stirred regrind mill and is ground to a p80 of 50 microns, using 5/8” high chrome balls. Rougher tailings report to the tailings thickener. The regrind cyclone overflow is sent to the single stage cleaner bank followed by two scavenger banks. The cleaner concentrate is pumped to the copper-nickel separation circuit. Cleaner tailings report to the tailings thickener. In the copper-nickel separation circuit, the pH is raised to 11.5 and a copper concentrate is recovered from the bulk cleaner concentrate in two stages, namely the copper roughers and the copper cleaner columns. The concentrate from the copper flotation columns is the final copper concentrate. The tailings from the columns return to the head of the copper-nickel separation. The nickel concentrate is the copper rougher tailings stream."

Jan 1, 2018

By Jeff Easton, J Johnson, D. Foot

The Mina Santa Rosa mine in Panama was the victim of a mine closure 24 years ago that left the community in dire straits. The mine showed the potential resources of greater than 1M ounces of gold and 4.5M ounces of silver. Veragold Mining Company decided to reopen the mine and address all the issues that were involved in the startup of an historic mine. This paper provides methods to restore the community trust, provide a transparent process, and develop an environmentally sound flowsheet. Immense scrutiny surrounded the Tailings Storage Facility, and the company developed a plan focused on paste thickening and surface stacking to eliminate the need for a conventional tailings’ facility. Paste thickener principles and benefits are also provided.

Feb 1, 2024