Search Documents

By Braden Lusk, Tristan Worsey, Nathan Rouse, Kyle Hall

Loading explosives up hole has challenges that are typically not seen in down hole explosive loading. Most explosives applications are not up hole. Lack of experience and technology can cause significant problems when loading explosives up hole. When results aren’t achieved, the blame is commonly put on the design when the true problems are unknown. Not knowing the cause of the problem causes drill and blast designs to be over engineered and very costly with little success. Being able to know and record key data is crucial to actually solving the problem. This paper goes over blast instrumentation that can be used to trouble shoot drill and blast problems in up hole explosives loading in underground mines. The tools and procedures used to trouble shoot include velocity of detonation recorder, borehole tracking, seismographs, and borehole camera. Each item will be discussed in detail with a case study to show the usefulness of the instrumentation. The operation discussed in the case study had issues pulling raises and had hang ups in the stope shots. These problems caused production slowdowns and costly remediation blasting that was not very successful. The case study is an underground gold mine that used modified sub-level caving with backfill as the mining method.

Jan 1, 2018

The safety of personnel is the most important matter during a mine fire. However, there is not enough research on a case when a fire occurs near a shaft and the behavior of the fire gas is not well understood. Therefore, a series of experimental study using a scaled ventilation circuit model was carried out. The behavior of ventilation air during a mine fire near a shaft was investigated. The model consists of two vertical shafts, three horizontal ducts connecting the shafts and an exhaust fan from the shaft bottom. The cross section of the shaft and duct is a square of 200×200mm. The height of the shafts is 3400mm. The length of the ducts is 1540mm. The lower duct is set at the same level as the shaft bottom. The middle and upper duct are set at 750mm and 1760mm above the shaft bottom respectively. The airflow rates through the ducts can be adjusted by regulators installed in each duct. The behavior of the fire gas was measured by anemometer, thermometer, and visualized using laser light .The air was ventilated downward in both shafts before the initiation of the fire. Some amount of fire gas of high temperature rose upward gradually along the shaft wall regardless of the downward ventilation after the initiation of the fire. Then the direction of main ventilation air suddenly reversed upward in the shaft. The direction of ventilation reversed in many places in the model and the fire gas reached even the part not anticipated.

Jan 1, 2009

By Oliver C. Ralston

[The NOJ'l..metals Division deals wi tt mi:leral n t inte .ded to be used a ra\o,f materials for extraction of metals. ~ _ ereas, a. materinl containing a chromite, if used' for production of c~1r()rrti1..1r.'l ::tetE' .. l or fcrrochromiu"1, 1,oJould be a chromi te ore, if used as 8. rcfrn.cto~J or for prod .1.ction of chromium chemicals, it is a chromi te-beari [. ~?oCl... Li;{eHise, a r:1a&neti te used for production of iron is a metallifero"'..ls ~in8re..i; if used 8.S a water-filtration granule in .:l magne.tically cleaned filter bed, it 'ould be a nonmetallic in-dustrial mineral.]

Jan 1, 1940

By S. Raghavan

An investigation of the possibility of improving the grinding characteristics of a gabbro ore containing copper and nickel sulfides via a thermal shock treatment technique has been carried out. The results obtained indicate that the breakage characteristics of the gabbro are particles can be significantly improved by preheating the are particles to a temperature around 400°C followed by rapid water quenching. For a given power input and feed size, the thermally treated material produces a product of much finer distribution than the untreated material. An assessment of the improvement in grindability has been made by calculating feed size selection functions for untreated and heat-treated materials.

Jan 1, 1981

By Eugene T. Sheridan

The process of converting coal into coke is known as carbonization. Essentially, carbonization is destructive distillation in which the volatile matter of coal is released when coal is he ted above its decomposition temperature and passes through a plastic stage before solidifying and forming coke. The mechanics of coke formation are complex, and the specific properties of certain coals that tallow them to "cake" or form coke are still unknown. Coke is a hard, cellular, carbonaceous mass, formed by heating coal in the absence of air. It is porous, irregular in size and shape, and is similar in appearance to wood charcoal. Coke, however, is denser, more porous, and more abrasive than charcoal.

Jan 1, 1965

By Eugene T. Sheridan

The process of converting coal into coke is known as carbonization. Essentially, carbonization is destructive distillation in which the volatile matter of coal is released when coal is heated above its decomposition temperature and passes through a plastic stage before solidifying and forming coke. The mechanics of coke formation are complex, and the specific properties of certain coals that allow them to "cake" or form coke are still unknown. Coke is a hard, cellular, carbonaceous mass, formed by heating coal in the absence of air. It is porous, irregular in size and shape, and is similar in appearance to wood charcoal. Coke, however, is denser, more porous, and more abrasive than charcoal.

Jan 1, 1965

By K. Mondal

A macroscopic approach integrated with microscopic analyses for wettability characterization is presented. Wetting depends on 1) Contact between the dust and the fluid droplets, 2) Wettability of the particles by the wetting fluid, and 3) Wettability rate (due to low contact times). The goal of this paper is to show that the wetting rate is a significant factor in dust control. Samples from the roof, three different horizons of the coal seam and the floor were pulverized to less than 25 µm. Experiments were conducted with known wetting fluids to correlate surface tension and equilibrium wettability. Further analyses were performed in terms of surface charge (zeta potential), particle size, mineral composition, elemental composition, and quartz content. The surface tension reduction was also achieved by the use of chemicals and/or altering the temperature of the water. Two methods were used to evaluate wettability rates: a) near real-time comparison of wettability rates, and b) comprehensive evaluation of the intrinsic wettability rates. The data obtained provides meaningful insights towards the design of engineering controls for an economical solution to dust control in coal mines.

Jan 1, 2012

By Brad Sampson

Project Ownership ?Discovery Metals Limited ?ASX (DML), BSX (DML), AIM (DME) ?Market Cap AUD 195M ?Key assets ?Boseto Cu ?Dikoloti Ni The Boseto Copper Project ?Location ?Setting ?History ?Status ?Future

May 1, 2010

By G. W. Jones, R. E. Kennedy

"INTRODUCTION In the manufacture, storage, transportation, and use of combustible gases and vapors, explosion hazards, which at times may be present when air becomes mixed with the gases and vapors, become of primary importance. Such conditions are especially dangerous where large volumes of gaseous atmosphere are involved, because an explosion under such circumstances is capable of doing tremendous damage to both property and personnel.Because of its interest in safety in the mining and allied industries, the Federal Bureau of Mines has investigated, and published results dealing with, the explosibility of various types of combutible atmospheres. The explosion hazards of natural gases have received attention, and results giving the limits of inflammability and ignition temperatures in air have been determined and published. 4/ Other investigations have shown how explosions of natural gas-air mixtures may be prevented by the addition of nitrogen and carbon dioxide. 5/Because of the increased demand for crude oil for war purposes, the application of secondary-recovery methods of stimulating oil production have received considerable attention during the last few years. The process consists in the injection of natural gas into partly depleted oil wells to cause the oil in the sands to flow into producing wells and so increase the amount of recoverable oil. 6/"

Feb 1, 1945

By Roberto Maldonado

El presente texto señala el proyecto de profundización en la mina Animón considerando sus características como: geología e hidrogeología, parámetros geomecánicos, niveles de producción, costos de capital y operación, eficiencia del sistema, flexibilidad para cambios en las operaciones, reservas de mineral y consistencia con el sistema de explotación. De forma que a través del conocimiento de estas y de las herramientas gráficas tridimensionales, se pueda analizar las diferentes alternativas, incluyendo condiciones que debe cumplir el proyecto de profundización, el cual abarca también los servicios auxiliares y ventilación.

Sep 12, 2005

By R. R. Klimpel

"SYNOPSISA discussion of the importance of flotation rate in the analysis of mineral flotation is presented. In particular, the highly interactive nature of the flotation ""system"" is emphasized where there are components of chemistry, equipment, and operating conditions simultaneously involved. It is further shown that: 1) flotation rate must be measured in order to economically optimize the performance of an industrial flotation circuit, 2) that consistent patterns exist in both flotation rate and equilibrium recovery when changing various settings of the system components, 3) that knowledge of these patterns is necessary in order to avoid making system changes that are either self-compensating or dramatically re-enforcing in some particular aspect of performance, and 4) the rate related role of the chemistry component (e.g.frothers and collectors) is often much bigger than is sometimes realized (especially in a negative sense involving overdosing of reagents). INTRODUCTIONFroth flotation is widely usedl-6 in mineral beneficiation processes as a method for separating different types of finely divided solids present in a liquid (usually aqueous) suspension. The approach is based on the contacting of solids with upward moving air bubbles in an agitated vessel where the solids are exposed to chemicals (collectors) which create a condition favoring the attachment of a certain portion of the solids to the air bubbles. This selected portion is then removed in a froth stabilized by chemicals (frothers) and subsequently recovered from the flotation vessel. Depending on the settings of the various components of the flotation ""system"" (see Figure 1) it is possible to achieve a wide range of flotation performance."

Jan 1, 1984

By R P. Bewick

Many future and current block and panel caves extract ore from veined rock masses. These rock masses are composed of open joints forming blocks or rock with healed networks of veinlets. These two types of discontinuities pose a challenge for rock mass characterisation and classification due to difficulties in distinguishing actually open joints from healed but weak veins when diamond core drilling and excavation blasting practices disturb the rock mass. The inability of separating characteristics of open joints and healed veins has often resulted in an underestimation of the rock mass quality and as a consequence led to inappropriate assessments of rock mass response to mining (ie rock mass behaviour) and consequently deficient excavation stability assessments and ground support designs. In this paper, guidelines are provided to improve the characterisation and classification of veined rock masses. It is shown how veined rock masses can be mischaracterised resulting in often incorrect forecasting of rock mass behaviour. Following this, the classification of veined rock masses is examined. It is shown how the primary classification systems (ie Q – Barton, Lien and Lunde, 1974; rock mass rating (RMR) – Bieniawski, 1976) may not lead to reliable ratings in veined rock masses if care is not taken to differentiate between open joints and veins of varying strength. Examples are provided to illustrate how the Q and RMR systems are insensitive to veining. Finally, an example of characterising a veined rock mass for design purposes is presented.CITATION:Bewick, R P and Kaiser, P K, 2016. Characterisation and classification of veined rocks for rock mass behaviour assessment, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 825–834 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By M. Q. W. Jones

This paper summarizes important features of a compilation of thermal properties of stratified rocks from Witwatersrand gold mining areas. The database consists of more than 1000 thermal conductivity measurements, more than 700 density measurements, and nearly 100 heat capacity measurements. Most important rock types and stratigraphic units are well represented. Heat capacity does not differ significantly from one rock type to another, and density is relatively uniform although particular rock types are characterized by distinct average values. Different rock types also have distinct thermal conductivities, but this parameter varies by a factor of four to five. Primary factors controlling the thermal properties are mineral composition, degree of metamorphism, and porosity. In addition, the temperature dependence of thermal conductivity and heat capacity of quartzite may significantly decrease the thermal diffusivity of this rock at deep mining levels.

Jan 1, 2003

Bateman Engineering managed the establishment of a second diamond treatment plant at the Letseng Mine in the Mokhotlong District of northern Lesotho, about 100 km from the town of Buthe Buthe. Letseng Diamonds Proprietary Limited, is owned 70 % by Gem Diamonds and 30 % by the Government of the Kingdom of Lesotho. The second plant, which commenced construction in late 2006, doubled Letseng Mines' hard rock processing capacity from 2.6 million t/yr to 5.2 million t/yr, making it the worlds' seventh largest diamond mine by throughput. Bateman Engineering provided the engineering design, procurement and construction management of the new plant.

Jan 1, 2010

By J. P. Rider

The number of extended cut mining systems has increased significantly in coal mines over the last decade, and there is a constant push to extend the face ventilation systems to even greater setback distances. The need to maintain airflow at setback distances of 12.2 m (40 ft) and beyond requires that methods for delivering intake air to the face be improved, or alternative ventilation techniques be implemented. The emphasis of this research effort was to examine various techniques to improve the distribution of available air at the mining face in order to reduce face methane levels. A study was conducted comparing the performance of a jet fan, used in conjunction with a machine mounted scrubber, with blowing curtain ventilation in a 27.5 m (90 ft) heading. In addition, a second study was performed on blowing curtain systems examining how scrubber flow, intake air velocity, and curtain setback influence face methane concentrations. Results showed that when the heading advances to a depth of 27.5 m (90 ft) blowing curtain systems were more efficient at diluting face methane levels when compared to a jet fan. Also, increases in scrubber flows and curtain velocity resulted in lower face methane concentrations for blowing curtain systems at 9.2 and 15.2 m (30 and 50 ft) setbacks.

Feb 24, 1997

By T. H. Chan

As the University of Hong Kong and their advisors planned their new Centennial Campus it became clear that they would have to re-provide existing water reservoirs on an adjacent site with new salt water reservoirs located underground in two new caverns. The existing reservoirs are owned by the Water Supplies Department who provide salt water for sanitary flushing and a separate potable water supply for regular use. Although underground reservoirs had not previously been adopted locally, the planning has been completed to a tight schedule and the construction is well advanced. The need to preserve historic buildings imposed constraints, as did the requirement to minimise potential construction nuisance for the local community and environment. This paper presents the background to the project and the work carried out to develop an innovative, sustainable and environmental acceptable solution. Construction progress to date is also presented.

By F. C. Langenberg, J. Chipman

Jan 1, 1959

By R. P. van Hille, A. W. van Zyl

The BIOX® culture, aiding liberation of arsenopyrite/pyrite occluded gold, is inhibited by thiocyanate (SCN > 1 mg/L); precluding the recycling of tailings water up-stream of the bioleaching circuit. The activated sludge tailings effluent remediation (ASTERTM) process is a biological process that was developed to facilitate water recovery and treat waste water on-site (to achieve a SCN concentration < 1 mg/L) to be recycled or disposed of. The aim of this study was to investigate the effects of changing temperature and SCN loading on the SCN degradation ability of the mixed microbial population clue to seasonal temperature changes and fluctuations of SCN concentration in the waste water.

Jan 1, 2011

Capture airborne respirable dust generated by an auger-type continuous mining machine to reduce workers&apos; dust exposure. Approach Install a water-powered scrubber system, operating at 1,400 psi, on the sides of the conveyor. The scrubber draws the dusty air from the face area and discharges cleaned air into the face return. How It Works Auger-type continuous miners pose unique ventilation and dust control problems. To protect face workers from the dust, the end of the brattice is usually maintained close to the face to increase ventilation effectiveness. However, it is taken down as the machine cuts toward the exhaust side to allow the machine to complete its cut. Often, the brattice is not reinstalled in a position to most effectively control

Jan 1, 1989

By J Bresnahan, D Kepert, R Murray, R Neroni

Stratigraphy of the Hamersley Province in Western Australia, featuring alternating units of banded iron formations and shales with contrasting electrical properties in a mostly gently undulating shallow-dipping layered geometry, is particularly favourable to airborne time-domain electromagnetic mapping techniques. Manipulated vertical cross-sections of modelled conductivity obtained from laterally constrained one-dimensional inversion of SkyTEM304 data enable the exploration geologist to interpret weathering profiles, shallow-dipping stratigraphy and steep structures, all of which are crucial aspects of bedded iron ore deposits genesis models.The Cobra Project is located 14 km east of the NNW-trending Menindee Fault Zone, which defines the western margin of the Hamersley Province, Western Australia. The region comprises an extensive plateau of Brockman Iron Formation cut by a series of horst and grabens with a regional dextral strike-slip component. The 150&#176; striking horst and grabens and associated 060&#176; striking conjugate faults have approximate frequencies of 400 and 2000 m, respectively, and control the bulk of the iron mineralisation. Syn to late 150&#176; trending dykes in part intrude the faults.In the Cobra region, elucidating the structurally dislocated stratigraphy without closely spaced drilling is very challenging. Geological mapping is hindered by the paucity of mappable stratigraphic markers within the banded iron formations and kinematic indicators. Airborne magnetic and remote sensing data sets highlight the dense lineament network, but provide limited assistance in quantifying relatively small apparent displacements, or distinguishing faults from dykes with reasonable confidence.Interpretation of modelled conductivity cross-sections generated from laterally constrained one-dimensional inversion of airborne electromagnetic method (AEM) data offers invaluable insight where the quality of mapping or drilling is wanting. Subsequent targeted field checking and infill drilling validated the geological model interpreted from the integration of these data sets.The AEM technique alone cannot decipher the complex geological environments often present in the Hamersley Province but can facilitate effective iron ore exploration by focusing precious field time and assisting structural and stratigraphic interpretations in areas with sporadic and shallow geological data.CITATION:Murray, R, Neroni, R, Kepert, D and Bresnahan, J, 2017. Using airborne electromagnetics to solve a structurally complex geological puzzle in the Hamersley Province, Western Australia, in Proceedings Iron Ore 2017, pp 269–276 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017