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By Jorge Alvarez

In a large-scale open-pit mining operation, continuous efforts are made to control damage to the slope walls. An essential tool in this effort is determining the PPVc (critical peak particle velocity) in areas of interest. By knowing this value and generating criteria, drilling and blasting designs can be established to reduce vibrations that affect wall construction. It is crucial to understand that the PPVc changes as different mining phases develop, especially due to exploitation on the benches, which leads to vertical inherited damage. Therefore, it is imperative to regularly update the PPVc based on field tests that provide accurate data. With this information, vibration damage criteria can be established, and drilling and blasting techniques can be designed to minimize the impact on the remaining rock mass. This document presents a methodology for generating scaled criteria that best represent the reality of the rock mass.

Jan 21, 2025

By Kota Nakashima

Residues from titanium smelting tend to contain scandium. The scandiumis discarded because no suitable process exists for its recovery from the residue. Valuable-metal recovery from discharged residue is critical for environmental conservation and to achieve a sustainable society. Since 2015, JXNippon Mining&Metals has been developing a process for scandium recovery from the residue of a titaniumsmelting process. The process consists of the following steps: scandium concentrating by classification or neutralization, selective scandium leaching, impurity removal by neutralization, solvent extraction of scandium by using D2EHPA, purification, and roasting. We optimized the above steps to achieve an effective process to obtain scandium oxide (Sc2O3). In this paper, we introduce results from the bench-scale test of the scandium recovery flowsheet developed by JX Nippon Mining & Metals.

By R Adamian, F. T. Da Silva, D. H. Gameiro

Schytill and Geldart diagrams were developed for the TiO2-C-Cl2 system at 1 073 and 1 273 K, so as to define the hypothetical relations between particle sizes and chlorine velocity for simultaneous fluidisation of mixtures of anatase concentrate and charcoal for carbochlorination. It was concluded that the operating limits on chlorine gas velocity will be controlled by the behaviour of the reducing agent, mainly because of its lower density. An increase in temperature from 1 073 to 1 273 K will have only a small influence on the fluid-dynamic behaviour of the mixture. For bubble fluidisation, the maximum sizes 0.413-0.478 mm for anatase and 0.529-0.611 mm for charcoal will be adequate. When the particle size distribution is large, fluidisation will be feasible only if conducted in two stages, otherwise the residence time of the small particles in the reactor will be very short. New diagrams will be needed for the gaseous chlorides in the second stage

Jun 21, 1905

By S. S. Clarke

THE opening of sheet-ground mines in which the ore beds are only from 7 to 9 ft. thick led the Commerce Mining and Royalty Co. to con-sider mechanical loading, in order to avoid the high cost of hand shovel-ing in such mines. Scraper loaders were chosen because the capital investment would be comparatively low; because they are small enough to be used in low working faces, and because they can be mounted on a mobile carrier.

Jan 1, 1939

By R. D. Stewart

Paper presented at the conference: Risk assessment in the extractive industries, held in Exeter, UK, 23-24 March 1994, and first published London: IMM, 1994, preprint volume, 18pp., 5 refs. A seismic risk assessment method has been developed for application to rockburst prone deep-level mining sites which have sufficient seismic coverage. The technique utilises several seismic hazard parameters simultaneously and assesses the seismic risk on a daily basis according to the individual levels of these parameters. Critical levels are determined from investigation of the long-term behaviour of the parameters in relation to recorded potentially damaging seismic events. The method has been applied to a data set comprising 15 months' worth of seismic data, with encouraging results

Aug 1, 1995

By S. Maemura

Miike Colliery of Mitsui Coal Mining Company, the biggest and oldest coal mine in Japan, is producing a quarter of the national coal production, about 5.2 million tons of clean coal annually and almost a half of which is now being mined under the "slicing Mining System". The slicing system is a mining method to mine a thick coal seam dividing it into two faces, upper and lower. Its history started nearly 20 years ago. However, the all-around modernization of this system has made little progress up to recent years, while mining methods for single longwall faces has made a remarkable progress together with the improvements in mining machineries, self advancing supports and so on. The reason was that the tremendous difference in adaptabilities of mechanized face equipments existing between the upper and lower faces has made it very difficult to increase the total production capacity of slicing system. After our persistent study for seventeen years, we have recently realized successfully the quite satisfactory slicing system, applying the combination of shield type self advancing supports and double ranging drum cutter at both faces. We are now fully convinced of that the high efficient, quite safe and improved slicing system has been basically established for the present. This paper intends to brief the transition on the combination of self advancing supports and mining machines, its results and further to detail the development of shield type self advancing support for upper face and artificial roof material which shall be the key point to be successful in full mechanization of slicing faces.

Jan 1, 1976

By Ellson I. G

Shay Gap was created for the sincrular purpose of housing, in comfort, the workforce that would be required to mine iron ore, from leases held by Goldsworthy Mining Limited, in hill country, approximately 170 kilometres east of Port Hedland in the Pilbara region of Western Australia. To combat the and environment, the Company ultimately decided to adopt a novel planning concept for the town, which had not been attempted before in Western Australia. The special problems encountered during planning, and the reservations that were expressed during construction and early settle ment, are now part of the dim past. During the three years of occupation now achieved, there has been accumulated a story of success in the provision of an acceptable alternative to modern suburbia. Not only may this be claimed, but it can also be argued that the Shay Gap concept has been a more successful solution to a real environmental problem in our arid Pilbara region than has been seen in other similar settlements.

Jan 1, 1976

By D. Robert Weir, Verner B. Sefton

The reduction roast-ammonium carbonate leach-hydrogen reduction process for laterites has been under development by Sherritt Gordon for the past 20 years. The process can treat high iron or low iron laterites, with some process modification, and gives extractions of 88-93% Ni or 82-88% Ni, respectively. Five campaigns on a 1 tonne per day Pilot Plant and four campaigns on a 35 t/d Demonstration Plant have been carried out on laterite from three different deposits, and many other laterites have been investigated in the laboratory. The Marinduque Surigao Nickel Refinery in the Philippines was designed on the basis of this work. The process comprises roasting to selectively reduce the nickel and cobalt in the laterite, leaching the calcine in ammonium carbonate to dissolve the metals, recovery of cobalt by precipitation of a mixed metal sulphide, concentration of nickel from the carbonate solution by basic nickel carbonate precipitation and recovery of high purity nickel by hydrogen reduction of nickel from ammonium sulphate solution. Ion exchange has been developed as an alternative to BNC and for recovery of trace nickel from BNC barren liquor. Details of the development of some of the process steps through the laboratory to commercial plant are discussed. The process metallurgy has been confirmed in the commercial plant.

Jan 1, 1979

By C. S. Griffith

Lithium Australia NL (ASX:LIT) and ANSTO Minerals have been working together since 2015 on the development of halide accelerated leaching for the extraction of lithium from lithium-bearing micas, spodumene and clays. This technology has been termed SiLeach® process. The driving force behind development of the SiLeach® process, initially, was to develop a hydrometallurgical process to extract lithium from micas and spodumene without the need for the energy intensive, high temperature processing conventionally applied to lithium extraction. This driving force remains today and continues to hold promise in realising the value of previously under-utilised lithium resources. A comprehensive understanding of the technology and its applicability to the processing of micas and spodumene currently exists, and the flowsheet has been rigorously piloted. Production of battery grade lithium carbonate has been demonstrate

By J. P. Ress

In 1903, seventeen years after mining of the Witwatersrand gold-bearing reefs started, the findings erf the Miners' Phthisis Commission (Transvaal) resulted in the initiation of measures with the object of controlling dust production. The substance of these measures was as follows: Removal of persons from places where they would be exposed to blasting fumes; use of water to suppress dust made in drilling and in other operations; supply and control of air to working-places; filtration of dusty air; and determination of the amount of the dust in the air. Broadly speaking, progress in dust control has followed these four lines with increasing success as the nature of the problem has become better known. Complete success has not, however, been achieved, partly because increasing mechanization of mining has intensified the problem and partly because the application of these measures is not infallible, being subject, in many cases, to human control. A brief summary of the development of these measures will lead to a description of present-day practice.

Jan 1, 1947

By C. H. Bucknam

A review of phase analysis methods used to characterize refractory gold ores is presented. Updating of assay methods using database technology, on-line instrument interfacing and response surface modeling is highlighted. The use of assay results to classify ores for metallurgical purposes is demonstrated.

Jan 1, 1987

By S. Ali Bastani, Ashley Varni

Design acceleration response spectra (ARS) are directly correlated with dynamic forces and estimated dynamic bridge displacements, which make them a critical aspect of dynamic bridge design. Nonlinear site response analyses are performed for a 1,400-linear-foot bridge site with a SC soil profile at the sides and a SF soil profile in the middle to evaluate the soil profile effects on the bridge analyses. One-dimensional seismic response analysis is commonly performed for site-specific response analysis. SHAKE or similar one-dimensional total-stress equivalent-linear approaches have been used since the 1970s. However, the equivalent linear method has deficiencies when the subsurface soils are susceptible to strain softening. Therefore, various assumptions are made when using the equivalent linear method by practitioners to estimate the SF soil profile site response. With recent advancements in constitutive models, effective stress models have become more popular. Although the effective stress models are generally more complicated and require additional input parameters, they shed further light on the liquefaction mechanism and its effect on the surface ARS. An equivalent-linear one-dimensional seismic response analysis and a non-linear effective-stress seismic response analysis, using DEEPSOIL, were performed to evaluate the ground surface ARS for a proposed bridge site in Orange County. The soil shear strengths were estimated based on cone penetration test results using empirical relationships. The shear modulus degradations (backbone curves) of soil layers were adjusted to match the estimated soil strength at failure. The ARS curves developed from each method were compared to determine the most suitable method for estimating a site-specific design ARS curve for a liquefiable site. Considering that the bridge abutments and the outer bents are founded in bedrock, while the middle bents are founded in liquefiable soils, ARS curves were created for each subsurface condition. Taking into account limitations of the structural analysis software, recommendations were made to combine the multiple ARS curves into a single ARS curve for the structural bridge design.

Jan 1, 2018

By W. G. Brunner

The slurry wall technique has undergone an evolution from its invention to its today’s status. In the early stages slurry walls were built with cable grab, later on with much stronger hydraulic grab and last but not least with the use of the cutter technique. The cutter allows thick walls with high verticality to extreme depths through hard soil and rock formations. With the rising demand of the construction of watertight diaphragm walls different joint systems have been developed. In addition to the rapid development of excavation systems it was necessary to improve slurry treatment and desanding plants, especially in conjunction with high performance trench cutters. Deep mixing methods can be used economically for the construction of cut-off or excavation support walls where other systems such as traditional soldier beams and lagging walls would yield unsatisfactory performance, where the installation of vibrated or driven sheet piles could cause vibration induced settlements and where concrete diaphragm walls would be time consuming and expensive. The new CSM method can largely replace the more conventional single or multiple auger methods of soil mixing or jet grouting. The cutter tool is similar to a cutter used in diaphragm walls or cut-off walls and is operated with a Kelly mounted on a drilling rig or rope suspended on a crane jib or mast of a base carrier. With this system much deeper walls can be installed and even hard soil layers can be penetrated.

Jan 1, 2007

By R. Rosenblum, J. Y. Kim, D. Shink, K. G. Stowe

"A small scale continuous flotation cell was designed and constructed at the Noranda Technology Centre to develop a mobile testing flotation circuit located next to the production circuit. This mobile small scale flotation pilot plant can easily and economically be set up at any circuit in a mill and used to evaluate and predict plant performance against a given flotation condition. The main feature of the cell, beside the provisions of automatic pulp level and feed rate control, is to provide a reduced surface to volume ratio approaching to that of an industrial machine.This paper describes the basic design and the results of various testwork carried out to date including aeration, conditioning, reagents, recirculation, flotation gas, etc. are presented in comparison with the plant production results. INTRODUCTIONStudy of the behaviour of an ore during concentration by flotation process starts, in general, with a series of tests in laboratory cells. Given the discontinuous nature of these tests, the information obtained by such a study is somewhat limited. It has long been recognized that laboratory test results are not always reproducible in pilot plant tests and subsequently, the pilot plant results do not always predict plant performance. The differences are often blamed on batch vs continuous operations, grinding media, size distribution, aging (oxidation), water quality, equipment, operator's skills, etc."

Jan 1, 1992

By Y Zhang, Z Zhao

The green production of the steelmaking process has urgent requirements for fluorine-free fluxes. In this article, a new solid waste-based slagging flux was applied in the external dephosphorisation test of low silicon hot metal to replace the traditional fluorite-lime dephosphorisation slag. The results showed that under laboratory conditions, the new flux was utilised for smelting low-silicon molten iron with a phosphorus content of 0.10~0.13 wt per cent, the temperature of the molten iron was 1350°C and the slag amount was controlled at 2 per cent. Within ten minutes of smelting, the dephosphorisation rate of the molten iron reached more than 50 per cent. When making slag with new flux, the slag melting time was about 40 seconds and the P2O5 content in the final slag was higher than 8 wt per cent. In the industrial test of a 150 t molten iron ladle, under the same molten iron conditions, an out-of-furnace dephosphorisation test was conducted in the Kambara Reactor (KR) process. The flux material consumption per ton of steel was 8~10 kg. Within 15 minutes of smelting, the dephosphorisation rate of the molten iron was about 30 per cent. During flux slag making, the slag melting time was about three minutes and the P2O5 content in the final slag was higher than 6 wt per cent. This new solid waste-based flux has significant cost advantages and outof- furnace dephosphorisation effects and is expected to become the benchmark for a new generation of fluorine-free steelmaking fluxes.

Aug 21, 2024

By Hideaki Kitajima, Ryo Sakamoto, Katsuya Sasaki, Maehata Hidehiko

The Electric Discharge Impulse Crushing System (EDICS) is a technology for carrying out crushing by using electrical power and nitromethane. It is designed for construction tasks such as splitting of concrete and rocks.The EDICS consists of an electric discharge generator that supplies a high-voltage high-current pulse, a cartridge that generates power by using electric discharge energy, and cables that connect the electric discharge generator and the cartridge. The cartridge contains a thin metal wire that evaporates because of the electric discharge energy and a nitromethane that reacts with this evaporated metal wire. The cartridge can be used to generate a high pressure on the order of gigapascals within a time interval of several hundred microseconds, and crushing power equivalent to that generated by explosives is generated during this period. In recent years, the EDICS has been widely used in Japan because of its good performance and favorable characteristics.

Jan 1, 2011

By Suzzann Nordwick

Over the past decade, significant advances have been made in the development of sulfate-reducing bacteria (SRB) technology to treat acid mine drainage (AMD). Bench-scale testing, field demonstrations, and engineered applications of SRBs for the treatment of AMD will be presented. Designs include an in situ bioreactor installed in the subsurface workings of the Lilly Orphan Boy Mine in 1994, the SRB bioreactors installed at the Calliope Mine from 1998 to 2001, the integrated biological reactors built at the Surething Mine in 2001, and the ongoing development of a replaceable cartridge system. SRB technology benefits include the reduction of dissolved metal ions to insoluble metal sulfides and the neutralization of the AMD resulting from the production of bicarbonate from the oxidation of organic nutrients. This paper will address engineering design criteria including the selection of organic media and system permeability and complete mitigation of AMD. Research was funded under Interagency Agreement No. DW899388-70-01-1 between the US EPA and the US DOE and was conducted by MSE Technology Applications, Inc., through the National Environmental Technology Laboratory (DOE Contract No. DE-AC22-96EW96405) at the Western Environmental Technology Office located in Butte, Montana.

Jan 1, 2003

By Pramila Misra, Jibardhan Meher, Debadutta Das

The concentrated coal-water slurry has been receiving considerable attention recently due its ability to replace fossil fuels. Attainment of stable and concentrated slurry has been succeeded so far through several physical and chemical techniques. The present article reports the formulation and stabilization of a highly concentrated coal-water slurry formed from five varieties of non-coking coals with variable ash contents obtained from Eastern part of India, employing three varieties of starch esters, such as starch benzoate, starch formate, and starch carbamate as dispersant. The apparent viscosity of the modified coal-water slurry has been measured by varying coal loading, dispersant percentage, pH, temperature, etc. The apparent viscosity of the slurry has been found to be decreased substantially on addition of 0.8% of adsorbate in the slurry. The particle-particle interaction has been considerably decreased and stable concentrated coal-water slurry containing high weight fraction of coal (61.5-63.5%) has been achieved in each case. The slurries stay in a non-settling form for about a month with viscosity in a permissible low range. The coal-water slurry has been found to behave as a non-Newtonian liquid. Comparison of the zeta potentials of the naked and modified coals evidences that adsorption of the dispersants at coal-water interface results in inhibition of the agglomeration of coal particles through mostly steric repulsions.

Jan 1, 2014

By G M. Volkmann

Pipe umbrella support systems – also called canopy tube systems – have been used successfully for tunnelling in challenging ground conditions since the 1970s. Historically, the drilling unit was the limiting factor for pipe umbrella installations – less attention has been paid to pipe couplings and their influence on labour time and load-bearing capacity.This contribution investigates the influence of the type of pipe connection on the load bearing characteristics of a connected pipe and discusses associated influences on design calculations and installation performance. Standard thread connections reduce the effective cross-section and thereby load-bearing capacity in the connection area. To achieve design parameters, over-dimensioning of the un-weakened pipe section is the only way to overcome this limitation. Recently, two new, alternative connection types were designed and developed for connected pipe umbrella pipes. The first one is the nipple coupling, consisting of fitting with a threaded connection that is pressed and welded into the ends of standard tubes. The second type is the squeezed connection, which mechanically connects non-threaded pipe ends, achieved by force-fitted squeezing from the drill rig. Both coupling types have technical as well as operational advantages compared to the common thread couplings, which are the weakest point in the support system.In the following sections significant technical differences are explained, design values given and a site example presented to illustrate the operational advantages of the newly developed coupling?type.CITATION:Volkmann, G M, 2014. Development of state-of-the-art connection types for pipe umbrella support systems, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 333–338 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Aki Fujii, Hiroshi Dobashi, Mitsuro Matsuda, Yoshinari Kondo

INTRODUCTION The Metropolitan Expressway Central Circular Route with a total length of approximately 47 km is located outside the Inner Circular Route of Tokyo (at a radius of approximately 8 km from the city center). Sections with a length of approximately26 km, slightly less than 60% of the total length, on the east and north sides are in ser-vice. Completing the Central Circular Route (Figure 1) is expected to enable through traffic concentrated at the city center to get around, and to form a well balanced trans-port network, which will alleviate traffic congestion considerably. The Central Circular Shinjuku Route, a section with a length of approximately 11 km on the west side, is now being constructed at a fast pace. The route is being built mainly by the shield tunneling method to carry out work smoothly under a trunk highway carrying heavy traffic and to reduce adverse effects of tunneling work on residents in the neighborhood. Shield tunnels have recently been becoming longer and deeper, and no secondary linings have been used in an increasing number of cases because of the over-crowding of cities or the reduction of budgets for public works. Economical, durable and high-quality segments have been required for linings of shield tunnels. Segments are made of concrete, steel, cast iron or combination thereof. Concrete segments are generally used in shield tunnels of medium to large diameter. Concrete segments are highly durable and resistant to compression, so they are highly resistant to earth pres-sure, water pressure and jack thrust. They are, however, heavy and have low tensile strength, so they are brittle and their corners are likely to spall. Concrete segments should therefore be handled carefully.[1] The authors have developed a steel fiber reinforced highly flowable concrete segment (referred as SFRC segment) that overcomes the weaknesses of concrete segments[2] to construct economical, durable and high-quality linings. SFRC segments have been applied to outbound sections SJ51 through SJ53 of the Central Circular Shinjuku Route. Unlike conventional concrete segments (referred as conventional RC segments), SFRC segments are made of steel fiber reinforced self-compacting highly flowable concrete. SFRC segments require less reinforcing bars than conventional RC segments because steel fibers are expected to work as reinforcements. Steel fiber reinforced concrete is a composite material that overcomes the brittleness of plain concrete, and has higher resistance to bending, tension and shear than

Jan 1, 2007