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By M. Didyk

In this report, the application of the PHU/MVS program is demonstrated through the use of a simple but realistic mine ventilation program. The report details, the problem description, the input data required and the various output features of the simulator. The PSU/MVS program is written in Fortran IV for use with IBM 370/168 computers. A version of the program that can be used in CDC computers is also available. A ventilation network consisting of 531 branches, 300 nodes and 5 fans took 48 seconds for solution on The Pennsylvania State University's IBM 370/168 computer. Appendix I of this report is the User?s Manual for the program. Appendices II and III contain the input data listing, and selected output listing for; the application. Appendix IV provides tables for leakage, friction factors and shape factors.

Jan 1, 1977

By Yuanbo Zhang, Zhaokun Tang, Mingjun Rao, Guanghui Li

The ballability of hematite ore with addition of a certain amount of pulverized anthracite and the induration features of anthracite–containing hematite pellets were studied. The results indicate that adding a certain proportion of anthracite can improve the quality of green pellets as well as the roasting performance of roasted pellets. The suitable mass dosage of anthracite is 1.0%–1.5%. Under the conditions of roasting temperature 1280 oC–1350 oC and roasting time 15 min–20 min, the compressive strength of roasted pellets is found to be more than 2500 N/P. Compared with hematite pellets in the absence of anthracite, the proper induration temperature is diminished by 20 oC, whereas optimal induration temperature range expands by 50 oC, and induration time is shortened by 5 min–10 min. Adding anthracite is an effective measure to improve the pelletization of hematite.

Jan 1, 2015

By L Köresaar, J Moilanen

With lower and increasingly variable Fe grades in iron ore resources, the monitoring of Si, Al, Mg and other light elements to meet quality requirements is gaining importance in the iron ore beneficiation industry. The high cost per manual assay and associated manpower requirements often limit the frequency of shift composite samples and laboratory assays. Furthermore, the shift composite assays represent past performance of a plant but are not useful for immediate reactions to feed variations, detection of equipment malfunctions or process control. Automated online analysis of light elements radically reduces the cost per assay and provides repeatable, timely data for process analysis, control and optimisation.A light element online slurry analyser, based on laser-induced breakdown spectroscopy (LIBS) optical emission technique, will be presented. This paper discusses the analyser design for the iron ore industry and also reviews the performance of the analyser against the manual laboratory. Additionally operator safety, user friendliness and maintenance requirements are discussed.A case study will also be discussed in this paper. The sophisticated measurement technique has been implemented in an industrial automated analyser and sampling system to allow for slurry measurement for up to 12 sampling points. However, careful selection of the sampling points and implementation of the sampling system is required for smooth operation.CITATION:Köresaar, L, Timperi, J and Moilanen, J, 2015. Optimised process control in iron ore via online analysis of light elements, in Proceedings Iron Ore 2015, pp 511–518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Danuta Szyszka

This paper presents results of tests performed to determine minimum concentration of a surfactant used at which coalescence of air bubbles during flotation has low probability to occur. The measurements of the critical coalescence concentration, also known as CCC, were carried out in a device consisting of glass cell into which air was pumped by peristaltic pump through capillaries. The flotation foam was recorded with a high resolution digital camera. Basing on the video records, average diameters of the air bubbles were measured and the values obtained were subsequently used to determine the CCC values. The author of paper determined the CCC values of surfactants tested using the linear regression method, and subsequently analyzed the results obtained. To define initially the capability of a tested surfactant to flotation, efficiency of multiparticle model flotation and flotation of individual size fractions were determined in a flotation apparatus for laboratory use in the presence of only foam making agent at CCC value pre-determined during the tests previously carried out. The tests of coalescence phenomenon were carried out with use of selected flotation frothing agents.

Jan 1, 2014

By W. D. Madeley

Synthetic minerals were made from pure starting materials and galena samples were doped with the title metals. Microscopic, microprobe and X-ray examination confirmed that the dopeants were in solid solution. Paired flotations in a Hallimond-tube apparatus were performed to determine relative flotation response using Aerofloat 238 promoter. Results of these tests show that silver-doped galena floats more readily than pure galena and that galena doped with bismuth floats less readily than pure mineral to a 95% confidence level. Galena doped with both silver and antimony as AgSbS2 shows no detectable effect. Antimony-doped galena followed the expected trend, but not to 95% confidence. The results are consistent with the theory that flotation by thiol-type anionic collectors is enhanced by p-type semiconduction.

Jan 1, 1978

By John Vynne

BHP’s Navajo coal mine installed drill monitoring and high precision navigation systems on their three overburden drills during 2002 and 2003. Details of the DrillNav system hardware and reporting system will be discussed, as well as the significant benefits Navajo has achieved since the systems were installed. Navajo is not satisfied with the current results and plan additional upgrades to the systems. In addition, Navajo plan to integrate the data from their drill systems with data from other systems to achieve even greater increases in drill productivity and to reduce overall mining costs.

Jan 1, 2007

By C. Tokoro

Co-precipitation of dilute toxic anions with ferrihydrite is an important removal mechanism in wastewater treatment system. Although, numerous qualitative studies have been published on removal characteristic from wastewater of dilute anions by co-precipitation treatment, detail mechanism or quantitative characteristic is not well understood. This paper discussed the co-precipitation mechanism of As(V) and Cr(VI) with ferrihydrite by comparative experiments between co-precipitation and simple adsorption. In this study, co-precipitation experiments and simple adsorption ones were distinguished closely. In the former, precipitation of hydroxides and adsorption of anions develop simultaneously, but in the latter, anions adsorb onto prepared hydroxides. Although high affinity anions for hydroxides (e.g. As(V) for ferrihydrite) showed quantitative difference of removal ratio between co-precipitation experiments and simple adsorption ones, low affinity anions (e.g. Cr(VI) for ferrihydrite) showed quantitative agreement in spite of deferent forms of ferrihydrites between them, that is, amorphous ferrihydrite was formed in co-precipitation experiments, but goethite was formed in simple adsorption ones. In order to discuss the mechanism of co-precipitation phenomena, three experimental studies have been carried out: (i) adsorption isotherm measurement in the co-precipitation experiments of As(V) or Cr(VI) with ferrihydrite, (ii) zeta potential measurement of co-precipitated or simple ad-sorbed ferrihydrite with As(V) or Cr(VI), and (iii) XRD analysis of co-precipitated As(V) for ferrihydrite. All experimental results suggested the main mechanism in co-precipitation phenomena of As(V) was not only a surface complexation (simple adsorption) but also a surface precipitation.

Jan 1, 2014

By N Clarke, J Hunt, A Barros, N Guerrero, L Keeney

Grade Engineering® (GE) involves a range of integrated technologies and operating protocols for improving effective feed grade through early rejection of low value material prior to costly processing activities and has the potential to transform the economics of large, low grade, mining operations. Extensive GE test work by AngloGold Ashanti (AGA) and the Cooperative Resource Centre for Optimising Resource Extraction (CRCORE) determined that the Gramalote gold deposit in Colombia is highly amenable to implementation of grade-by-size screening to upgrade the ore at a production scale. To understand the relationships between geology and the upgrade response drill core and bulk samples were analysed at the Centre for Ore Deposit and Earth Sciences (CODES) as part of a larger CRCORE project to understand geological controls on grade-by-size deportment, i.e., the tendency for specific mineral phases to preferentially fractionate during breakage into different size fractions. This work is focussed on understanding the role of mineralogy and texture in influencing rock breakage and natural fractionation at a range of scales. Detailed logging of Gramalote drill core and mineralogical analyses including hyperspectral logging, portable and bench-scale X-ray fluorescence (XRF), plus low resolution Laser Ablation of intact drill core pieces, combined with data from site (drill logs, geochemistry, petrophysics) were used to evaluate the ore and alteration mineralogy, vein paragenesis and textural variability. This provided information on gold deportment and allowed the identification of favourable host veins. Bulk sample material from different ore grade zones was also analysed. A comparison with the results of GE testing shows that positive upgrade results are produced by rocks with abundant veins, particularly those associated with potassic and/or white mica alteration. This work indicates upgrade response can be predicted from drill core using data collected by a combination of automated systems including hyperspectral data, XRF, and detailed drill core logging.

Nov 10, 2020

By R Williams, M Baxter, D Zink, R Cunningham

The purpose of this paper is to discuss the efficient operation of a tailings dewatering circuit comprising a thickener and filter press through proper control and automation. It is common to see thickeners and filter press circuits each with their own control systems. This can cause multiple issues when trying to increase efficiency and reliability of the tailings management process. By automating the thickener and filter press controls, you are eliminating any delays and inconsistencies caused by human error and process variations. When done properly the system can maintain a consistent product as the feed characteristics change. Previously, operators would have to monitor the process parameters and adjust the system accordingly. This can now be accomplished using state of the art process control equipment that continuously monitors and adjusts critical variables using Programmable Logic Controllers (PLC) and Proportional Integral Derivative (PID) loops. The paper will detail the control theory used to maintain these systems, highlight other benefits of having a fully integrated plant such as predictive maintenance and remote diagnostics as well as present examples of how these have been implemented in field examples.CITATION:Baxter, M, Cunningham, R, Williams, R and Zink, D, 2018. Tailings process optimisation through automation and controls integration, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 416–421 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By V. Kecojevic

Environmental and economic costs related to equipment fuel consumption and carbon dioxide (CO2) emission present a substantial challenge to the mining industry. Haul trucks are an integral part of the overall surface mining system and they consume a significant quantity of fuel. Consequently, they produce a significant amount of CO2. The objective of this research is to (i) establish a mathematical relationship among a truck?s fuel consumption, power and engine load factors and (ii) determine the amount of a truck?s CO2 emission and the associated cost that may arise from potential CO2 legislation. In order to achieve these objectives, the authors have considered original equipment manufacturer (OEM) haul trucks, which are commonly used in surface mining operations. The research presented here may be used by mining professionals to help determine the cost and environmental burden of the trucks? application and efficiently manage energy consumption.

Jan 1, 2010

Calaverite is a gold telluride found in the Kalgoorlie region, Fiji, Cripple Creek Colorado and numerous other locations. It is known that a high pH is necessary for calaverite cyanidation, with the leach rate increasing substantially above pH 12 due to the hydroxide ion concentration. In most circumstances lime is used to achieve high pH, however lime saturates at approximately pH 12, limiting the maximum pH obtainable in a critical region for calaverite leaching. Plant observations, laboratory experiments and thermodynamic modelling show that the maxi-mum hydroxide ion concentration that can be achieved with lime (CaO) is strongly dependent on common ions. The presence of calcium, as commonly found in saline waters, substantially diminishes the maximum pH that can be obtained with lime. Conversely the presence of sulfate ions, as generated through oxidation of sulfides, substantially increases the maximum pH that can be achieved with lime. Sulfide oxidation during cyanide leaching of complex ores may generate acid and sulfate ions, making overdosing with lime at the front of the circuit, or staged addition down the leach train, important to maintaining the maximum hydroxide concentration.

Jan 1, 2014

By T. Wohlford

Due to the increases available base of scientific knowledge, increased independent review required by worldwide security exchanges, and the need for accuracy in characterizing mine water resources, it has become necessary to produce a more accurate hydrologic balance. This presentation provides a critical review of the steps and tools to compile a complete hydrologic review of a mine property. The forces of regulation, increased scientific analysis, better tools, and stakeholder expectations have created a perfect storm of accuracy demand. Ausenco has developed protocol to achieve the desired end.

Feb 23, 2014

By H. Lazreg

This paper presents an evaluation of surface resistivity techniques as a tool for delineating salt-water intrusion in Shippegan, N.B. The study consisted of resistivity profiling, resistivity soundings and a limited number of induced polarization soundings in selected areas in the Province of New Brunwick. The results from resistivity profiling indicate that when seawater intrusion occurs in a sandstone formation the resistivity contrast is sufficiently large to allow a precise delineation of the intrusion. A formula is then derived to convert resistivity values to chloride concentration in the "cone of intrusion". The results from resistivity soundings showed that shaly formations may have resistivities as low as seawater-contaminated sandstone. An indeterminacy has resulted from this resistivity overlap. A limited number of IP soundings were performed in an effort to resolve it. The results showed that IP can be of appreciable help in resistivity interpretation.

Jan 1, 1972

By J Nantel

Planning of modern mines entails considerable challenges in the areas of ground control, materials handling, safety, environment, equipment and personnel. Many orebodies are not economical unless efficient mining systems are used to win the ore. Relentless pressures are placed on mine operators to force them to become more productive and to make mines more competitive in modern economies. This has generated an intense drive to adopt technologies that rely on a greater degree of mechanisation, automation and computerisation. There is no turning back; high technology in mines is here to stay: computer controls and monitoring, computer aided mine design, information management systems, etc. During the past 20 years significant advances have been made in the areas of mine design, mine equipment and geomechanics. One could rhetorically ask if the advances in mine backfill technologies have kept pace with developments in other sectors of the mining industry. This paper will look at a few key mining technology sectors and will compare the relative progress of backfill technology to these sectors.

Jan 1, 1998

By Glenn C. Miller

Cyanide is the most common lixiviant for extraction of precious metals, and its efficient use in open pit mines has contributed to the increase in world production of gold during the previous two decades. With this expansion of precious metals mining using cyanide, public concerns have developed in response to the inherent public perception of cyanide as a tox-in as well as a series of environmental problems that are directly or indirectly related to cyanide use in open pit mining. Some of these have technical or regulatory solutions, while others will require additional investigation before they can be resolved. The following discussion will summarize some of the public concerns regarding the use of cyanide in precious metals mining. The issue of cyanide use in large scale precious mining is controversial, and recent banning of cyanide use in open pit mines in Montana, or complete banning of cyanide in Hungary has reflected those international concerns. The underlying basis for some of the bans (e.g. Montana) reflect a general concern of the environmental impacts of mining, rather than specific issues related to risk of cyanide use. The human safety record for cyanide use, particularly in the developed countries is good, and cyanide is clearly the most efficient lixiviant for precious metals. Indeed, the relatively short lifetime for cyanide in the environment renders it one of the less problematic chemicals used for extraction of gold from ore. Mercury amalgamation or use of bromide as a lixiviant are certainly much more problematic. What, then, is the basis f~r the international concern about precious metals mines that use cyanide. Ifuse of cyanide for gold recovery is to continue, what additional infom1ation needs to be developed that will allow a better management of the risks of cyanide? Which of the concerns are directly related to cyanide, and which are indirect concerns that more related to effects of open pit mining. Under what conditions should use of cyanide be discouraged? DUl::ing June of 2000 the United Nations Environmental Program conducted a two-day workshop on cyanide use in mining that was attended by persons from the mining industry, regulators and environmental community. Support and attendance at this workshop reflected concerns by all three groups on further restrictions for cyanide use and the emerging potential for guidelines for better management of the catastrophic release of cyanide-containing mining waste. The following discussion is meant to focus-on those risks and explore the basis for an often negative reaction to precious metals mining using cyanide. It is presented in the format of a statement, followed by a discussion. While admittedly provocative, the statements are meant to express the concerns? of the public regarding cyanide and the mining industry.

Jan 1, 1998

By Ameir Altaee

Unconventional means and methods were utilized to install over 650 contractor-designed micro-piles for the replacement of the Bronx approach to the Bronx-Whitestone Bridge in New York City. The method utilized reverse circulation (RC) drill rods and down-hole-hammers (DHH) along with grouting through the DHH bit. The overall construction sequence of drill-down, grout-up, place reinforcing is similar to auger-grout piling. The extremely tough drilling conditions required the use of a percussive DHH. The piling subcontractor refers to this pile as a hammer-grout pile. Project background, constraints and subsurface conditions are given. The proposed means and methods as well as the collaboration between stakeholders are detailed. Results of load testing and production installation are summarized.

Jan 1, 2010

By D. F. Malan, L. Scheepers

Seismic risk in the deep gold mines of South Africa has been studied for many decades. A clear understanding of the effect of geotechnical conditions on the seismic hazard nevertheless remains elusive. Certain reef types seem to be associated with a higher risk of rockbursts. The stability and deformation behaviour of excavations on the different reef horizons are affected by the rock types and the varying strength properties. The seismic response to mining is therefore also expected to differ according to the geotechnical conditions. As a case study of this behaviour, the seismicity at Mponeng mine was investigated. On the VCR (Ventersdorp Contact Reef) horizon, two areas can be delineated. On the eastern side of the mine, the footwall is shale, and on the western side it is a strong brittle quartzite. More large-magnitude events occur in the area with the shale footwall than the area with the quartzite footwall. Moment tensor analyses indicated that the majority of the large-magnitude events are not related to geological structures, but are face-related, implying that shear failure of intact rock is occurring ahead of the mining front. Preliminary modelling indicated that the closure volume for the shale footwall may be higher than that for the quartzite footwall, providing a possible explanation for the observed difference in seismic response.

Mar 2, 2022

By W. E. Anderson

As part of a larger study to identify factors influencing the practical operating life of wire rope used on large draglines in surface coal mining, field trips to operating surface coal mines were made during late 1975. Wire rope performance information was obtained from personnel at thirteen mine sites west of the Appalachians. Seventeen pieces of equipment, utilizing buckets ranging from 30-to 220-cubic-yard capacity, were documented. We have judged that U.S. surface coal mining draglines, 30 yards and larger, can be represented as 120 machines having 60-cubic-yard buckets, moving 1.8 x 10 yards of overburden during 6,650 hours of productive availability per year. Based on our limited field study, we have calculated that downtime resulting from rope-related causes averages 105.6 hours per year for each (typical 60-yard) dragline. The total lost production from this source alone is thereby estimated at about 25 x 10 yards annually. Although study findings did not reveal anything about dragline rope life that wasn't known or practiced by one operator or another, most operators could expect improved rope life by periodic review of their practices and by adopting or adapting one or more life-improvement measures employed at other sites. Since rope productivity was found to vary by about five to one, among the sites studied, we believe considerably improved average performance is possible. As little as ten percent overall improvement would mean increased national productivity exceeding two million yards of solid overburden removal, and associated savings in rope costs alone of some two million dollars annually, not to mention any reduction of labor-related expenses. This report outlines preliminary findings which may prove useful to many operators in extending wire rope life, thereby lowering expenses and increasing surface coal mining productivity. Some of these modifications or adjustments in maintenance/operating practices would not require capital investment. We did not find anyone who had tried cost reductions by using presocketed dump

Jan 1, 1977

By AIME AIME

APPARENTLY unperturbed by any misgiving as to ill luck connected with the mystic number thirteen -for there were exactly that number of Directors on deck-the Board held two sessions on Tuesday, Feb. 21. , . Between the executive session at 5:15 p. m. and the general session at 8:30 p. m., 28 Section and Division delegates were wests of the Directors at dinner. Committee chair- " men and past officers brought the attendance to 75. Messrs. McAuliffe, Merica, Mudd and Tally had expressed their intention to be at the Directors' meeting, but each was prevented unavoidably at the last minute. At the executive session of the Board, J. V. W. Reynders was unanimously chosen to fill the unexpired term of Dr. Becket as Director: and Eugene McAuliffe in like " manner was selected to become Vice-president to fill the vacancy created hy Dr. Becket's assumption of the Presidency. Upon nomination of President Becket the following Executive Committee was appointed: Frederick M. Becket, chairman; Howard N. Eavenson, H. A. Guess, J. V. W. Reynders and William Wraith; and the Finance Committee was appointed as follows: Henry Krumb, chairman; Paul D. Merica and H. G. Moulton. Karl Eilers was reelected Treasurer and A. B. Parsons was re- elected Secretary to serve for the ensuing year, whereupon the executive session was adjourned.

Jan 1, 1933

By Ann M. Hagni

The mineralogical, chemical, microtextural, and particle size character of electric arc furnace (EAF) dusts are being studied by reflected light microscopy, scanning electron microscope-energy dispersive spectroscopic analysis (SEM-EDS) and electron probe microanalysis (EPMA). The dusts consist predominantly of metallic iron, iron oxide, and calcium-iron-manganese silicate phases, together with smaller amounts of iron-manganese-zinc-calcium, iron-calcium-zinc-manganese, and calcium-iron-manganese silicates. The samples vary in their zinc contents. Chlorine occurs in phases containing iron, lead, zinc, manganese, and calcium. The dust particles range greatly in size from 1 to more than 300 ~m, but most particles are about 1 to 6 ~m. Larger particles. about 20-50 um across. also are present. They are predominantly spherical in shape, but some are cenospheres, and others are more angular particles, some of which are broken spheres and cenospheres. Their internal microtextures exhibit evidence of liquid immiscibility, exsolution, skeletal crystal growth, and oxidation react i on rims. Because EAF dusts have been classified by EPA as hazardous wastes, there is heightened interest in the treatment of these dusts to render them non-hazardous. The mineralogy of products of pyrometallurgical treatment of EAF dusts by flash furnace and pyrohydrolysis are currently under study.

Jan 1, 1991