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By Amos Bryant, Jesse Davis

This paper compares the predictions of the latest Institute of Makers of Explosives Safety Analysis for Risk (IMESAFR) model versus physical test data recovered from ISO-1 and ISO-2 tests in Woomera, SA. ISO-1 testing included placing 1054 kg (2324 lbs) of ANFO (ammonium nitrate-fuel oil) inside an ISO container on a flat bed truck. ISO-2 testing was identical except the NEW was 4000 kg (8818 lbs). The IMESAFR predictions are based on model runs using the best match available to the actual donor type involved in the test. This type of debris analysis is not the standard output of IMESAFR, as the program is designed to assess the probability of human fatality. However, all of the IMESAFR predictions presented were obtained from the use of the actual model equations and algorithms without adjustment. Test results from ISO-1 and ISO-2 will be presented as well as findings from the comparison between model results and actual explosive results from the ISO testing efforts.

Jan 1, 2010

By Mariano Iberico Miranda

El presente texto señala el proyecto minero San Marino. Este unidad es propiedad de la Cía. Minera "El barón" y se ubica en el distrito de San Mateo, provincia de Huarochirí, Lima. Asimismo comprende la geología, reservas, sistema de minado (método de explotación, laneamiento Y sistema de minado propuesto.

Sep 1, 1980

By M. M. Wong

Salt mixtures consisting of KC1, BaC12, and HfCl4 with RbCl or CsCl were investigated as electrolytes for refining hafnium. The presence of RbCI or CsCl in the electrolyte appeared to suppress the volatility of. Best electrorefining was obtained with an electrolyte containing 50.7 percent KCl, 27.l percent BaCl2, 15.7 percent CsCl, and 6.5 percent HfCl4. In this electrolyte, hafnium metal with an average oxygen content of 470 ppm was produced from an anode feed containing l,600 ppm oxygen. All metallic impurities were lowered, except titanium, manganese, and tin.

Jan 1, 1966

By Gamal Rashed

Coal bump is a sudden manifestation of the release of strain energy stored in a coal pillar (Peng, 2008). It is a very serious mining hazard that adversely affects the safety and productivity of the mines. Several case histories in mining have described coal pillars or faces of coal failing violently with an accompanying ejection of debris and broken material into the working areas of the mine (Campoli, 1987; Osterwald, 1962; Peperakis, 1958; Garvey and Ozbay, 2013). These failures resulted in large losses of life and total collapses of entire mine panels (Chase, Zipf, and Mark, 1994; Zingano, Koppe, and Costa, 2004). There are questions in the literature about whether or not the coal itself plays a significant role in bump. Rice (1935) mentioned that structurally strong coal is one of the key factors for bump; however, the strength of the Pocahontas #3 coal seam is low, and it bumped. Moreover, it is not obvious in the literature whether the strength of the tested coal samples is the inherent strength or if it is influenced by the shape or the size of the specimen. The main objective of this paper is to answer the following question: To what extent does the mechanical properties of the coal have an impact on the potential for violent failure? The best approach to answer this question is to compare the mechanical properties of two kinds of coals from bump-prone (Utah coal-Sunnyside seam) and non-bump-prone (WV coal-Sewickley seam). This comparison includes uniaxial compressive strength, modulus of elasticity, shear strength (cohesion and friction angle), and the burst index.

Jan 1, 2014

By Nikzad Oraee, Parham Khajehpour, Kazam Oraee, Arash Goodarzi

"Rock fall related accidents continue to occur in coal mines, although artificial support mechanisms have been used extensively [1]. Roof stability is primarily determined in many underground mines by a limited number of methods that often resort to subjective criteria. It is argued in this paper that stability conditions of mine roof strata, as a key factor in coal mines, must be determined by a survey which proactively investigates fundamental aspects.Failure of rock around the opening happens as a result of both high rock stress conditions and the presence of structural discontinuities. The properties of such discontinuities affect the engineering behavior of rock masses causing wedges or blocks to fall from the roof or slide out of the walls [2]. A practical rule based approach to assess the risk of a roof fall is proposed in the paper. The method is based on the analysis of structural data and the geometry and stability of wedges in underground coal mines. In this regard, an accident causing a huge collapse in a coal mine leading to four fatalities is illustrated by way of a case study. A comprehensive investigation of the hanging wall has been gathered through a systematic collection of evidence. The investigation results are then analyzed, and an interpretation of the evidence gathered is provided.For this purpose, horizontal and vertical profiles are prepared by geophysical methods to define the falling zone and its boundaries. The collapse is then modeled by the use of sophisticated computer programs in order to identify the causes of the accident and hence recommend corrective actions to prevent or minimize reoccurrence probability of similar accidents. The corrective measures are placed into a rule-based framework for the benefit of the mine operators.INTRODUCTIONRoof rock failure has generally been the most dangerous hazard for underground coal mining in the world. Failure of rock around shallow coal mine openings often results from loosening of blocks of rock on the weakened planes under the influence of gravity. This condition is not typically seen in large deep coal mines. There are a number of differences between large mechanized mines and small mines related to ground control [3]."

Jan 1, 2015

By Leming Ou, Qiming Feng, Yiping Lu, Pengyu Zhang, Qing Shi, Kun Liu, Guofan Zhang

"This paper introduces the mineralogical analysis of certain polymetallic copper-zinc ore in China with the aim of improving the flotation process. The main valuable elements, mineral phases and compositions of run-of-mine ore were inspected by the X-ray Fluorescence (XRF) and chemical analysis. For a deep known of the old process defects, Mineral Liberation Analysis system (MLAs) was employed to investigate the minerals liberation degree of selected key slurry points. Analysis results show that the run-of-mine ore belongs to the original copper-zinc polymetallic symbiotic ore at low oxidative level, which mainly contains 0.16% Cu, 4.43% Zn and 0.88% Sn. Gangue minerals are mainly silicate minerals, and zinc mineral is sphalerite. MLAs test illustrates that about 86% sphalerite has been dissociated in zinc flotation feed. In the current flotation process, over grinding of sphalerite monomer and insufficient liberation of intergrowths are the key problems need to be solved imminently. Up to this point, a new process consisted of two steps roughing unit is submitted in this research. It contributes two positive effects on zinc flotation performance: (i) separating sphalerite monomer timely to decrease overgrinding; (ii) improving zinc minerals intergrowths liberation efficiency. Flotation results indicate that the zinc concentrate grade increased 0.90% and the recovery improved 0.96% in the new flotation processINTRODUCTION Mineralogical analysis mainly focusses on solving mineralogy problems in minerals processing, assisting in minerals behaviors prediction and control for separation engineering (Falkovich, et al., 2001; Hillier, et al., 2003; Schouwstra and Smit, 2011). Process defects searching becomes its ordinary work, and flotation optimization appears to be its targets gradually. For example, Lucky Friday mine company (Idaho America) fails to obtain qualified lead concentrate as the change of ore properties (Nadoll, et al., 2011). Mineralogical analysis ascertains that there are too many dissociated sphalerite, pyrite and gangue particles exist in lead concentrate. According to this, more cleaning units are added to solve problems effectively. Kanowna Belle mine (Australia) takes a flash circuit in operation successfully with the aim of optimize flotation process, under the helps of mineralogical analysis and industrial test (Newcombe, et al., 2013). Lotter N.O. (2011) gives a deep description on how mineralogical data assisting mineral processing engineers to design and optimize flowsheet. For decades, quantitative and automated mineralogy techniques (Andersen, et al., 2009; Gu, et al., 2012; Oghazi, et al., 2009; Yu, et al., 2007) get well developed and hugely improve the veracity and repeatability of minerals properties measurement. Among these, MLAs (Gu, 2003) provided by JKMRC (Julius Kruttschnitt Mineral Research Center) is critically acclaimed all over the world. This analysis system can measure mineral phases composition and content, particles size, minerals occurrence and liberation degree directly."

Jan 1, 2018

By B. J. Scheiner

Extraction of silver from silver mill tailings by an electrolytic oxidation procedure was investigated by the Bureau of Mines. Various parameters affecting silver extraction, such as electrolysis time, particle size, and dissolution of the silver as the tetrachloro or cyanide complex, were studied at 30° C with an electrolyte concentration of 20 weight-percent sodium chloride. Resulting silver extractions ranged from 77 to 90 percent, depending on the tailings being treated. Concomitant extraction of mercury ranged between 90 and 95 percent. Power consumption was 52 to 90 kilowatt-hours per ton for the tailings investigated. Comparative experiments using direct cyanidation resulted in extraction of 46 to 82 percent of the silver and 20 percent of the mercury. Cyanide consumption ranged from 3.3 to 9.4 pounds per ton of tailings, depending on the tailings being treated. Silver and mercury were recovered from leach solutions by precipitation on iron powder, followed by conventional distillation and fire refining steps.

Jan 1, 1972

By John J. Dunkley

Recent years have seen the increased use of hydrometallurgy in the smelting and refining of metals. However this is often used as a final refining step, following an initial pyrometallurgical smelting process. Huge amounts of material are produced as melts which have to be cast, comminuted, and taken up into solution or leached. A common method is to granulate the melt and then grind it. In the case of metallic melts this can be difficult or unfeasible due to the ductility of the granulated particles. Water atomisation is capable of replacing the granulation and grinding stages with a single process step that can process in excess of 30t/hour of melt into particles as fine as 50 microns. Applications in operation in Co, Cu, Ni, Ag, Au, Pt and Rh refining are discussed together with potential applications in copper smelting.

Jan 1, 2003

By J. P. Evans

The modem copper smelter today utilizes tonnage oxygen for smelting concentrates, generating a high strength S02 off-gas leaving the smelter vessel. This gas stream, which also contains any unreacted oxygen, plus C02, N2 and H20, also carries with it the volatilized portion of heavy metals in the feed, plus partly oxidized sulfide concentrates. The time/temperature history and subsequent treatment of this off-gas stream emerging from the smelting furnace exit up to the acid plant can influence the partitioning and segregation of heavy metals in the off-gas circuit. Depending on this history, the type and characteristics of the chemical and physical reactions which. occur in the gas handling system can be influenced. This fact can also be used as a tool to adjust the separation of copper from heavy metals. In this paper, the impact of different time/temperature histories of the gas, due to different furnace geometries .and design, on the subsequent formation and characteristics of the smelter dust is examined. Based on the available data, several case histories drawn from examples using both bath and flash smelting technologies are analyzed from this perspective.

Jan 1, 1992

By N. Jovanovic, A. Vazirizadeh

"The main objective of this study is to find a solution to design a mass flow observer system with the minimum required sensors and maximum observability for a mineral processing plant. The second objective is designing a mass flow observer configuration with high reliability to manage sensor failures. This configuration will provide a robust monitoring system that increases plant availability and process measurement fault detection. Furthermore, the monitoring system is expected to improve process efficiency. In this investigation, the procedure of designing an observer system is presented along with three models to design the sensor network. The advantages and disadvantages of each models are discussed and finally the models result for an industrial case are presented and analyzed. INTRODUCTION The concepts of observability and redundancy of mass flow are directly linked with the ability to solve and estimate the mass flow. There are hundreds of streams in a process plant flowsheet, and for technical and economic reasons it is not possible to measure all mass flows. It is thus important to know for a set of measured streams, which of the unmeasured streams can be estimated. The concept of observability deals with this issue. It is also valuable to know whether a measured mass flow of streams can be estimated even if a sensor fails for some reason. Redundancy deals with this failure question. A stream is said to be observable if it can be estimated by using the measurements and/ or mass conservation equations. Also, a stream is redundant if it is observable even when its measurement is removed. Observability and redundancy analysis can be exploited for adding new measuring instruments. It can also play a useful role in efficient decomposition and data reconciliation problem (Narasimhan and Jordache 1999). The value of an observer system cannot be justified without considering its benefits. This justification is done through evaluation of data reconciliation, gross error detection and improving process performance such as outlined below:"

Jan 1, 2018

By L. Figueroa

Electrochemical methods have potential to treat waters impacted by mining, while simultaneously producing a recoverable metal product to off-set treatment costs. Mining-impacted waters may present challenges with electrochemical treatment due to low concentrations and complex solutions of numerous dissolved metals. This paper presents an evaluation of the potential strengths and limitations of abiotic electrowinning of mining-impacted waters. In particular the impacts of chemical composition on metals removal are evaluated. Results of bench-scale experiments demonstrate the potential to remove metals on the cathode (copper, cadmium, lead), as well as the anode (manganese). Pre-treatment for iron and aluminum may be needed and post-treatment pH adjustment would be necessary. INTRODUCTION Due to continually increasing demand for metals, new technologies and innovative applications of existing technologies are needed to recover metals from mining-impacted waters. Electrochemical methods have long been used for metallurgical processes with solutions containing high concentrations of the target metal. However, electrochemistry also has potential to treat waters with lower metal concentrations, while simultaneously producing a recoverable metal product to offset treatment costs. Electrochemical water treatment may have several benefits over traditional alkaline treatment for acid rock drainage (ARD). Sludge produced from alkaline treatment has high water content that is difficult to dewater, even for treatment plants producing a relatively high-density sludge. For example, the Argo Tunnel Water Treatment Facility (Argo Facility) in Idaho Springs, Colorado uses hydrated lime to produce a high-density sludge with a solids content of 20 to 25 percent and filter cake with solids content from 30 to 35 percent [1]. Furthermore, costs for managing the sludge are significant, approximately $90,000 per year for treating approximately 150 million gallons of water [1]. Although not the case for the Argo Facility, sludge produced from alkaline treatment of ARD has potential to be classified as hazardous. Disposal of sludge also opens up the potential for future liability depending on the sludge’s chemical stability and methods of disposal. In contrast to alkaline treatment, electrochemical treatment produces metals in elemental and other highly-dense forms on the cathode. If metals concentrations and flow rates are sufficiently high, the metals recovered may help offset overall treatment costs. In addition, sludge production would be reduced, if not eliminated altogether, thereby reducing both disposal costs and potential future liabilities as well.

Jan 1, 2019

By K. Hakalehto

El uso de métodos modernos en el uso de chimeneas de las minas en Finlandia permite obtener un mejor desarrollo racionalizado de la mecanizado. En ese sentido, el presente texto señala dos métodos seguros y rápidos para la perforación de chimeneas. La perforación para estas chimeneas se desarrolló en rocas duras duras y fuertes en 1972. Asimismo, el costo, itinerario y velocidad son factores a considerar en el empleo de métodos para perforación de chimeneas.

Jan 1, 1982

By M. H. Kline

The Chestatee mine is one of several well known pyrite deposits in Georgia that are reputed to carry appreciable quantities of copper with the ore. The deposit is? in Lumpkin County on the Chestatee River, 6 miles northeast of Dahlonega (fig. 1). Old records and reports indicated the probable existence of an extensive unmined ore body, but the mine is inaccessible at present. The Bureau of Mines, after studying old maps and records, decided to cor8-drill along the strike of the lense beyond the limits of the indicated old workings in an attempt to extend the possible reserves. The advantageous location of the property indicates that it could become an economic source of pyrite to be used for the manufacture of sulfuric acid. Iron sinter resulting from the roasting of the ores could be sold at a premium in the Birmingham, Ala., area, and the copper content could be extracted to help replace the nation's depleted resources of this metal.

Jan 1, 1949

By G. Geremia, M. I. Serrano, L. Costa, Strohaecker

The advances in electronics and the development of more efficient algorithms, allow for the designing of more complex and sophisticated automated systems. The new devices include lighter, faster, reliable, and stronger robot manipulators. One available technology, with relatively low cost, is a simple robot manipulator controlled by remote control. The device has been designed to be used in both mining and law enforcement, where it can be useful for inspection, rescue, gas analysis, and even to manipulate dangerous objects, such as explosives. The applications may even include the rescue of trapped miners in risky environments. The major advantage is the fact that the robot can be controlled with a remote and monitored through a video camera, minimizing human exposure to hazardous areas, where robots can perform tasks in an aggressive atmosphere and confined spaces. This article presents a mining robot manipulator controlled by remote control, using video cameras for positioning and sensors for movements, which are located on the operator's arm. With this system, it is possible to create a sensation of virtual reality, allowing easy operation for anyone trained in dealing with explosives, rescues, or other dangerous tasks. Blasting and mining are becoming perfect applications for robots, and its use should increase very soon. The results are discussed and presented for the brand new Xiru 01 robot manipulator.

Jan 1, 2010

By K. Krishnapisharody, G. A. Irons

"The modeling of gas-liquid plumes in steelmaking ladles has been the subject of many investigations. In most studies, the “modified” Froude number, based on the momentum of the injected gas, has been employed to characterize two-phase plumes. This approach has several shortcomings and is critically reviewed in the present work. Based on an extensive review of previous work and theoretical considerations, it is demonstrated that the injected momentum and consequently, the modified Froude number has no significance to gas blowing operations in Ladle Metallurgy. Instead, an approach based on the “plume” Froude number, previously shown by the authors as the proper form for Froude similarity, is extended as a simpler alternative.IntroductionGas injection is central to most Ladle Metallurgy operations. During ladle processing, the steel melt is usually stirred by an inert gas like Argon through porous plug(s) fitted in the bottom of the ladle or a lance inserted deep into the melt. The purging serves several purposes viz., homogenizing the melt, flotation of inclusions, enhancing the rates both of refining reactions and dissolution of alloying elements and promoting inter-phase interactions in the ladle.The topic of gas injection into liquid baths has been the subject of several investigations in the past. A great deal of this work, both experimental and computational, was devoted to describing the structure and properties of two-phase plumes as reviewed recently [1]. Generally, the ascending two-phase mixture is sub-divided into three distinct regions [2]: the jet core, transition and the bubble plume, respectively. The jet region, where the momentum of the injected gas is transferred to the bulk liquid, is also called the ‘momentum region’. In a similar manner, the plume is called the ‘buoyancy region’ where the motion of liquid is caused by the buoyancy force exerted by the bubbles. The proper characterization of these regions is important for the analysis and modeling of stirring operations in Ladle Metallurgy. Although many mathematical correlations exist for this purpose, some issues of theoretical and practical interest to the modeling of gas-liquid plumes need further attention."

Jan 1, 2012

By G Cavanough, A Olsson, J Rock, A C. Torrance

There are various methods currently in use to determine detonation performance of bulk explosive products including velocity of detonation (VOD), high speed photographic analysis, fragmentation analysis and unconfined detonation of samples. For assessment prior to detonation the current practice is limited to a measurement of cup density. This paper presents additional techniques that have been developed to provide measurement and assessment of bulk explosive products. Techniques applicable prior to detonation include a mobile laboratory to allow on-site chemical and physical analysis of sensitised products and ‘in-hole density’ measurement to monitor the in-hole density during sleep time. Assessment of detonation performance is achieved using detonation pressure sensors. These sensors allow measurement of detonation pressure, average VOD, propagation time and magnitude of the pressure induced in the explosive column by detonation of adjacent blastholes.CITATION:Cavanough, G, Torrance, A C, Rock, J and Olsson, A, 2015. Measurement and assessment of bulk explosive products, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 477–484 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

Discussion of the paper presented at the North Staffordshire Institute of Mining and Mechanical Engineers' general meeting held in Stoke-on-Trent, March 27th 1916, with Mr. John Gregory, President, in the chair, included contributions by Gregory J., Cadman J., Hartley J.W., Wain E.B. and Henshaw A.M., followed by the author's reply

Dec 1, 1916

By William Skinner, Jonas Addai-Mensah, Keith Quast, David Robinson, Jason Connor

A review of the laboratory- and pilot plant-scale physical separation techniques for the beneficiation of nickel (Ni) laterites shows limited efficacy. To date, the only upgrade technique adopted commercially, prior to hydrometallurgical processing of Ni laterites, is the removal of a barren, coarse size fraction in the feed by classification. In the present work we investigated two low grade (~ 1%), goethite-rich Ni laterite ores’ upgrading by magnetic separation, attritioning/coarse, (lower Ni-grade) gangue rejection and flotation techniques. Low intensity (0.1T) dry magnetic separation at ambient temperature of raw samples and those pre-heated at temperatures up to 450 °C showed evidence of pay metal Co and Mn bearing asbolane and/or lithiophorite minerals pre-concentration in the magnetic fractions. Ni distribution, however, did not show any noticeable magnetic upgrade but followed the weight distribution. Other ore pre-treatment methods (e.g., desliming and sulphidisation) followed by froth flotation with anionic and cationic reagents also led to noticeable (~35%) Ni upgrade. This is due to the deportment of Ni across several gangue host mineral phases (i.e. Fe oxide/hydroxide and a range of silicate/aluminosilicate minerals). From chemical analysis, after disaggregation of ~ 1% Ni grade feed ore, coarse (-600 + 38 µm) and fine (-38 µm) fractions of ~0.6% and 1.3% Ni grades respectively, were also produced, suggesting that a significant upgrade in Ni content can be achieved by rejecting the + 38 µm fraction with the loss of <40% of the Ni. The ore mineralogy, particularly the complexity and high number of un-liberated Ni-bearing phases, greatly compromises physical separation methods for these ores, with the possible exception of screening after disaggregation of the fines inherent in the run of mine ores.

Jan 1, 2014

By Paul G. Dunn

The planning of underground mines is a complicated process involving geological, engineering and operational constraints. MIRARCO is in the process of developing a 5D Mining Exploratorium where 3D mining models are combined with time (4th dimension) and costs (5th dimension). The mining exploratorium is a collection of external and inhouse software packages specifically geared to help underground mining companies arrive at better mine plans. This paper discusses the progress made in the development of the 5D Mining Exploratorium and a change in mine planning philosophy by conducting frequent audits in a Virtual Reality Laboratory. The development of genetic algorithms for optimising stope sequences is also presented.

May 1, 2003

By Guo Xueyi

The dissolution behaviors of valuable metals, lead and zinc, from secondary fly ash generated in municipal incineration plants were investigated using some lixiviants: sulfuric and hydrochloric acids, acetic acid and some chelating reagents including L-asparaginic-N,N-diacetic acid (ASDA), a biodegradable, and therefore, environmentally benign novel chelating reagent. It was found that zinc exists mainly as ZnO, whereas Pb probably as PbOHCI and PbO, and the easily soluble components in SFA are KCI and NaCl. Suitable amount of HCI can dissolve all of lead and zinc from SFA. Sulfuric acid can selectively extract zinc leaving lead in the residue. Ethylenediaminetetraacetic acid (EDTA) is an effective chelating reagent to extract both zinc and lead. Although ASDA and diethylene¬triaminepentaacetic acid (DTPA) can selectively extract more than half of lead from SFA, it would by no means be regarded as highly effective reagents for the extraction of these metal values. Keywords: Lead, Zinc, Secondary fly ash, Leaching, Dissolution

Jan 1, 2002