Search Documents

By D Johansson, C Yi

Blasting techniques are widely used to fragment rock masses into smaller pieces. Numerical modelling is an efficient method employed by many researchers in the blasting field. It is difficult for a conventional continuum-based approach such as the finite element method (FEM) to model the rock fragmentation by blasting and the expansion work on the rock by explosive and its detonation products. In this paper, the particle blast method (PBM) was employed to model the behaviour of the detonation and a bonded particle model (BPM) was used to model the brittle material to be blasted. A mortar cylinder with a centrally placed hole for the explosive was modelled and the results were compared to the experimental data. The blast process from crack initiation to fragment formation was analysed. The influence of coupling ratio on fragmentation was also investigated.CITATION:Yi, C and Johansson, D, 2015. Discrete element modelling of blast fragmentation of a mortar cylinder, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 793–798 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

By Eberhard Gock

The worldwide implementation of corrosion protection of low alloyed automotive metal sheets by zinc coating has led to supply shortages of zinc free non-alloyed steel scrap in the foundry industry. In a collaboration project, partly financed by the German government, with partners from the automotive industry, zinc metallurgy, scrap trading, foundry industry, and plant construction, a new acid-based pre-dezincification process has been developed, and a pilot plant with throughput of about 100 t/d has been put into operation at the Clausthal Umwelt-Institut GmbH (CUTEC) together with the Clausthal University of Technology in Germany. During the treatment process, acid from a zinc metallurgical plant will be supplied, which can be recycled to the primary zinc extraction process after raising the zinc concentration to more than 130 g/L zinc. This way, the separation of small amounts of iron by precipitation and the electrolytic zinc winning are outsourced and, as a result, the pre-dezincification process runs waste-free. In Germany, the amount of zinc coated ?new scrap? is approx. 3 million t per year with a zinc content of approximately 60,000 t per year. The possible additional incomes for the dezincified steel scrap are in the order of ?40 to ?50 per ton of scrap, the gained zinc content during the acid dezincification defrays the costs of the process, if the throughput is more than 700 t/d. In comparison to conventional dezincification during the electro arc furnace process followed by upgrading in a rotary kiln (Waelz process), the acid dezincification process running at a maximum of 50°C will cut the energy costs by up to 74% and the CO2 emission by up to 88%. In fact, a demonstration plant is being designed right now and will be installed for processing a part of the zinc coated metal scrap from the Volkswagen AG in Wolfsburg, Germany. Keywords: steel scrap, zinc-coated steel, dezincification methods, acid

Sep 1, 2012

By J. Seidel

In 2009 Newmont Mining Corporation’s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Jan 1, 2012

By JOE SIERAKOSKI, W. R. Hardwick

This paper , which describes mining methods and practices at the Johnson Camp copper -zinc mine , Coronado Copper & Zinc Co. , Cochise County , Ariz . , is one of a series being prepared by the Bureau of Mines on mining methods , practices , and costs in various mining districts of the United States . Johnson Camp is in the eastern foothills of the Little Dragoon Mountains in secs . 23 , 24 , 25 , and 26 , T. 15 S. , R. 22 E. ( fig . 1 ) . The mining property is in the low, rolling foothills at an altitude of slightly over 5,000 feet above sea level ( fig . 2 ) . The area is covered with scattered grass and small desert shrubs . The climate is mild , with hot summers and mild winters . The average annual precipitation is about 12 inches . The nearest surface water is the San Pedro River , some 12 miles west of the mine . The property is owned by the Coronado Copper & Zinc Co. , Los Angeles , Calif . This report gives a brief history of the property , describes the general geology of the area and of the ore deposits , outlines the methods of prospecting and exploration , and gives the methods of sampling and of estimating ore reserves . Development and stoping methods are explained . Underground transportation , ventilation , mine drainage , and safety measures also are described . The last section gives a brief description of the milling practice .

Jun 1, 1957

By J. Seidel

In 2009 Newmont Mining Corporation’s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Jan 1, 2012

By Marcella Mateus de Mello

O presente trabalho objetiva analisar a influência da distribuição de intensidade espacial do laser na geração de padrões de speckle em superfícies metálicas. Os padrões de speckle estudados são obtidos quando o laser atinge uma superfície metálica. A análise da imagem de padrões de speckle pode ser relacionada com a rugosidade de superfícies metálicas iluminadas com o laser. Com esse estudo pretendemos melhorar a sensibilidade das medidas de rugosidade de superfícies metálicas a partir das imagens de padrões de speckle.

Aug 17, 2017

By L. Juteau

"""The north coast of the St. Lawrence River will be the scene of an industrial development during the coming decades"". The facts which underlie this statement are the occurrences of iron and titanium ore, the abundance of hydro-power and the availability of deep-water ports in this region. Havre St-Pierre, Sept-Iles, Port Cartier and Baie Corneau already exist as major ports and urban centers. The huge quartz deposit at Baie Comeau will be a decisive contributing factor in the development of a metallurgical plant in this area. Due to its purity, it lends itself, first of all, to the manufacture of glass of different kinds, being comparable to the quartz sands now used by the plate glass and glass container industries in the Montreal area, Moncton, N.B., Trois-Rivieres and - in the future - at Bécancour, Quebec. However, its high quality will also make it possible to use it as one of the main basic materials for the production of silicon carbide and ferrosilicon, and as a flux in metallurgical processes. It is intended, in this report, to offer conclusive proof of the economical importance of this large quartz deposit by presenting the results of the studies made to date."

Jan 1, 1971

By Cleo Griffith Rall

The method for determining the effective porosity, of oil- and gas- bearing sand described in this report is a development of an earlier method devised by Bureau of Mines. The apparatus has been improved and made more convenient to use, but the procedure has been in use for many years without essential changes. A tabulation at the end of the report gives the results of more than 2,000 porosity determinations for oil sands in the fields of 13 states. A selected bibliography of articles containing descriptions and evaluations of various methods of determining porosity Is a. part of this report. The method was devised and developed at the Petroleum Experiment Station at Bartlesville, Okla., as part of the Bureau's research on fluid-energy relationships and ,on methods of improving the recovery of crude oil from underground reservoirs.

Jan 1, 1949

By PHILIPP HARTLIEB, Peter Schimek, Thomas Seidl, Paulo Couceiro, Pablo Segarra, José A. Sanchidrián, Juan Navarro

This paper describes a new methodology to assess rock mass-quality to guide blasting in open pit operations. A developed Structural Block Model and Strength-Grade factor have been combined in a Rock Factor, that, exclusively obtained from drilling data, can provide an automatic assessment of rock structure, strength, and waste/ore identification.

Feb 1, 2020

By Xie Zhang, Chongyang Zhao, Qingyun Huang, Bing Xie, Xiaopeng Zhen

"Extracting vanadium from vanadium containing hot metal into vanadium slag by BOF is the main vanadium production process in China. In this paper, the influence of Si content in hot metal on the quality of vanadium slag is analyzed. Synthetic vanadium slag with different SiO2 content were melted at 1673 K and then cooled to 303K at the cooling rate of 3?/min. Optical microscopy, SEM, EDS and XRD were used to analyze the mineralogical phases and crystallization behavior of vanadium slag. The results show that vanadium slag mainly contains spinel phase and silicate phase; V is enriched in the spinel phases while Si is concentrated in Fe2SiO4 CaFeSi2O6 and (Fe,Mn)2SiO4 as silicate phase. The melting point of slag increases gradually with the addition of SiO2; whereas viscosity decreases with an addition of 15~19% SiO2 and increases with an addition of 19~27% SiO2.IntroductionVanadium is an important element which is used almost exclusively in ferrous and non-ferrous alloys. The major vanadium products include FeV, V2O5, V2O3, VN and Al-V-Ti alloy. Furthermore, vanadium slags are mostly produced by oxidizing the elements in V-containing hot metal during a duplex refining process. Therefore, the process of removing vanadium from hot metal has its significance on the subsequent process[1].The extraction of vanadium is greatly affected by the mineralogical composition of vanadium slag[2], the distribution of the elements between the spinel and silicate phases and its physic-chemical properties. These characteristics of vanadium slag have been studied in some details. It has been reported that Si mainly exists mainly in the form of silicate which wraps the spinel crystals while small amount of Si stands as phosphorus quartz or diopside[2]. Chen et al.[3, 4] points out, when SiO2 content in vanadium slag increased every 1%, V2O5 decreased 1.48%. Moreover, silicate phases would embarrass the oxidation of V-containing spinels through decreasing the exposing probability[5]. Meanwhile, melting point and viscosity of vanadium slag has been greatly influenced by the SiO2 content. Therefore, this work attempts to analyze the above-mentioned questions systematically."

Jan 1, 2012

By J R. Barber, B. E. Rogers, R. Fukuzawa

Mercury is sometimes present in non-ferrous ores including gold, zinc, copper and lead. The selection and use of appropriate mercury abatement technology is critical for preventing its release to the environment during ore processing and to protect workers from mercury exposure. This paper presents a general decision-making process for mercury abatement technology selection for major emission sources in the gold industry. Mercury abatement can be accomplished through making process changes and/or by adding a process step to an existing system (i.e. "end-of-pipe control"). Advantages and limitations of the technologies along with waste / by-product management options are discussed through case studies of current operating mercury abatement systems.

Jan 1, 2015

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

Flotation works very well for particles that are typically in the range 20 to 150 µmin diameter, for base metal ores. In this range, it is possible to get quite high recoveries in conventional flotation machines. Outside this range, the recoveries decline progressively, whether it be with the very fine or the coarse end of the size spectrum. In this paper, the reasons for the drop-off in recovery are briefly reviewed, together with strategies for future work. Recent progress in the author's laboratory will be described. These include the Concorde Cell, which takes advantage of the high dissipation rates in the shock wave created when a gas-liquid mixture reaches supersonic velocities. The environment thus created is very beneficial for the flotation of ultrafines. For coarse particles, the reasons for the drop-off in recovery can be related to the highly turbulent nature of the pulp in a conventional flotation cell. To improve recovery, it is necessary to find a way of bringing particles and bubbles into contact in a quiescent environment. A new process for coarse particle flotation will be described, in which a fluidized bed is created in the flotation cell. The flow conditions are very gentle, and the high solids concentration leads to rapid rates of capture of the particles. Experimental results are presented. It is apparent that the maximum floatable size for coal and minerals can be increased by a factor often over the limits found in current practice. Advances

Jan 1, 2009

By Phillip E. Butler

Since early 1973, the Pennsylvania Department of Transportation (PennDOT) has been actively engaged in the utilization of coal mine refuse in the design and construction of highway embankments. The Soils and Geological Engineering Division of the Bureau of Materials, Testing and Research has the task of managing the program which includes field investigations, laboratory testing, engineering evaluation, planning, coordination, implementation, construction control, and review of construction performance. The objectives of the utilization program, in removing colliery refuse banks and utilizing the material in construction, are the environmental and aesthetic rehabilitation of those areas in the Anthracite and Bituminous coal fields which have been plagued for such a long time by air and water pollution, and unsightly landscapes; and the economic rehabilitation of those areas occupied by refuse banks by providing usable land which can now be developed as residential, business, or industrial sites.

Jan 1, 1975

By W. D. Judge, Z. W. Xiao, G. J. Kipouros

Rare earths have taken a prominent position in the Hi-Tech field after the discovery of the NdFeB permanent magnets. Their use in the magnets sparked miniaturization of the communication devices such as computers and mobile phones and are being considered in many more applications. Potential applications of rare earth elements in energy conversion technologies including wind turbines, photovoltaics, and other renewable energy systems are reviewed, along with sustainability considerations and production processes.

Mar 1, 2017

By Nagarajkumar BV

Pavai-and TeampT JV started working on the project T49A, Sumbar J & K State as part of slope and earth stabilization for ongoing Banihal - Katra Railway Connection Project. This project has several tunnels and bridges with slopes that are protected with various types of protection system such rock bolting, rock anchors, and micro piles. For the main two bridges Bring number 2 and 3 at T49 A location Pavai - TeampT JV has to design and execute the circular group of micro piles (Fig.1) for deep excavation of earth for the purpose of construction of well foundations (CAISSON FOUNDATIONS) for both bridge 2 and 3 piers. In this paper we discuss about the purpose, basic design, detailed design approaches and actual work implementation of micro pile with composite rock bolt applications and permanent rock anchors for slope stabilization works in this project.

Nov 1, 2022

By R. Shimpo

Equilibrium calculations by a computer may sometimes fail in giving solutions when the system includes a large number of components and more than three phases, and especially when no definite information about stable phases is given. An improved method of calculation is presented in which the number of phases need not to be initially fixed, phases can appear or disappear in the course of' calculation and a new method is combined with the Newton-Raphson method to obtain solutions easily. The improved method is applied to the copper smelting operation and all the successive stages of the operation are successfully simulated.

Jan 1, 1983

By Askari-Nasab, D. Checkel, K. Awuah-Offei

Life Cycle Assessment (LCA) is an emerging environmental management tool for examining environmental impacts from cradle to grave. In this paper, LCA is used to evaluate the acidification potential (AP) and global warming potential (GWP) of belt conveyors and truck haulage systems in a surface gold mine using the ISO 14040 standards. The results show that, for AP, the truck system has 32 kg of equivalent SO2 per functional unit, compared to 8 kg for the conveyor system. However, for GWP, the conveyor has 2,820 kg of equivalent CO2 per functional unit, compared to 648 kg for the truck option.

Jan 1, 2009

In 2009 Newmont Mining Corporation?s annual global spend on grinding media reached $94M USD, having doubled in the five years since 2004. The major contributing factor to the spend escalation during this period was unit consumable price, with total media consumption also rising as a function of annual ore tonnes milled. In an effort to better understand and manage the growth of this expenditure a significant supply chain management program was implemented. This was complemented by a series of technical initiatives focussed on grinding media specifications, quality management and the prediction of grinding media wear rate as a function of physical ore characteristics. This paper discusses the methodology and outcomes of these activities.

Nov 1, 2011

By Shenghui Chu, Zhibiao Guo, Dongshan Yang, Yuanxin Zhao, Xiaohui Kuai, Jingwei Gao

The technology of automatically formed roadway without pillars (AFRP) via roof cutting and pressure releasing (RCPR) is a reformatory method for gob-side entry retaining, which automatically creates a roadway by utilizing the fragmenting and expanding properties of rock strata and the mining pressure, to realize a novel technique for coal mining without coal pillars. The Anju Coal Mine is the first kilometer-deep mine where this technology is applied. To conduct a geomechanical model experiment, this research uses the 5307 working face in this mine as its backdrop. The experimental results show that this technology can efficiently decrease the pressure of the AFRP surrounding rock. The roof maximum stress of the AFRP is 21% lower than that of the belt roadway, while the side abutment pressure of the former is 13.4% lower than that of the latter. The comparison of model experiment data and field monitoring data shows that the roof and floor approaching deformations on the roof-cutting side and solid coal side of AFRP differ by 8.8% and 9.6%, respectively. The model experiment results and field monitoring data show good agreement, and the deformation of the AFRP surrounding rock can be successfully managed by this technique. The study’s findings can serve as a guide for using this technology in kilometer-deep coal mines.

Jul 31, 2023