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By V. Yahorava

Resin-in-pulp (RIP) technology has recently often been considered for the direct recovery of base metals and uranium from dense pulps. Implementation of RIP will eliminate the requirement for any solid-liquid separation downstream of leaching and has the potential to combine the recovery and purification steps, hence reducing both capital and operating costs. The recovery of the valuable metal is expected to be higher when RIP is used, especially where the leached solids are difficult to settle or filter, and to wash. The main concerns about the use of RIP for uranium recovery from dense pulps are the impact of silica on the resin?s metallurgical performance and the operating costs that would be associated with resin loss. Although a number of resin manufacturers have been developing much improved RIP-grade resins, it is critical that the most cost-effective resin be selected. Mintek currently is doing a significant amount of work on silica fouling of RIP-grade strong-base resins in acidic leach liquors and the effect it has on the performance of the resin, including its durability. This paper describes the results of the test work done on silica fouling and its impact on plant design input data. Resin durability test work was done using various laboratory techniques, but durability was also evaluated on a relatively large scale using actual pumps, screens, and mechanical agitation. Based on the results generated, a preliminary economical evaluation was done to estimate the impact of resin loss on the overall economic viability of a specific application. Keywords: resin-in-pulp, silica fouling, resin loss, equilibrium, kinetics, elution, durability, mechanical strength, resistance to attrition.

Jan 1, 2009

By Wawa Jaka Sungkawa, Slamet Rachman Jaka, Tom Dermody

Nowadays, with such a focus on environmental protection, surface mining activities have come under pressure to ensure their activities do not adversely affect the local surroundings. As part of the extractive process, blasting activities are an integral part of a mining company’s operational cycle. Consequently achieving beneficial blast results while complying with environmental requirements has become a key focus. This especially is the case when firing blasts within close proximity of residents where additional control measures need to be implemented to control vibration. One case where this occurs in Indonesia is in the Paringin Pit, one of the operational areas of the company's. The pit has complex geological conditions and is surrounded by several residential areas. Between 2014 to 2017 there were 12 cases of ground vibration exceedance due to blasting. As part of a continuous improvement project the company's targeted minimizing the vibration exceedance in this area. A project was undertaken to research and develop a method to confidently predict vibration. It was decided that the scaled distance formulas were not adequate to predict vibration when using non-electric detonators, as accurate wave propagation could not be achieved. The problem is how to manage of complex geology condition related with wave propagation in ground vibration control. Geological condition mapping with specific spatial range can and combine with Signature Hole Analysis be a solution to make wave propagation easier to accommodate in ground vibration control. With this new approach geological condition mapping with specific spatial range was produced that would minimize vibration while ensuring beneficial blast results. Introducing the new prediction produced nil cases of vibration exceedance in 2018 and beyond and proved that the Signature Hole Analysis in specific spatial range of geological condition is the preferred method to optimize blast result and maintain vibration control.

By W. L. Dare

Tri-axial strains in pillars, created by pillar robbing, were measured in an experiment at the Dysart No. 1 uranium mine near Grants) New Mexico. At this mine, room-and-pillar stoping is used on the advance, and pillars are recovered on the retreat. The are deposit is, for all practical purposes, horizontal. Measuring devices were installed in pillars approximately 90 to 200 feet from the break line, and strains were recorded over a 4-to 6-week period. The measurements indicate that, in general, the algebraic magnitude of vertical strains increased, and the horizontal strains decreased, in turn, indicating that vertical (or near vertical) loads on the instrumented pillars lessened as pillars were recovered.

Jan 1, 1962

By R Moreby

This paper is a demonstration of the techniques developed during an Australian Coal Association Research Program (ACARP) funded research project aimed to develop aids, principally computer based, to assist mine personnel to more efficiently manage significant incidents in coal mines. These aids include software to aid in the location of the incident, electronic information storage and retrieval, online site emergency response manuals and software to aid in decision-making.

Jan 1, 2005

Safety remains a critical priority for the Australian mineral resource industry and will receive increased focus in the future. This is particularly evident in underground coal mines where reserves are becoming deeper and more hazardous to extract. The CSIRO, through its Exploration and Mining Division, have recently delivered on two projects aimed at providing step-change capabilities in real-time risk management and hazard control. This paper describes the key outcomes of these projects.

Jan 1, 2005

By CHONG WEI, TATYANA KATSAGA, DEREK APEL

This study provides an effective determination process of the interface microstructural parameters in the numerical modelling of the mechanical interaction between two different geomaterials involved with frictional-bonded interfaces, such as the interaction between backfill columns and the surrounding rocks, or the soil-structure interaction, by using the coupled finite-difference and discrete-element (FD-DE) method. Three-dimensional numerical direct shear tests were conducted on the coupled FD-DE model of the combined rock-cemented rockfill (R-CRF) specimens with the frictional-bonded interface. With the microstructural parameters determined, the macro-mechanical properties of the interface of the coupled model were calibrated to well fit with the theoretical values of the combined specimen under the direct shear condition assumed according to the Mohr–Coulomb strength criterion. Evident elastoplastic shear behaviour was observed on the interfaces, and excellent agreement was attained between the shapes of the theoretical and simulated shear stress-displacement curves of the coupled models at different servo-controlled normal stresses. Particulate-scale force chains inside the DE model of the CRF specimen were highly consistent with the force contour on the FD model of the rock specimen, demonstrating the shear stress evolution of the coupled model at different shear displacements. Parametric studies verified the effects of the deformation properties of the interface parallel bonds on the shape of shear stress-displacement curves of the coupled models. The test results validated the feasibility and rationality of the coupled FD-DE method for modelling the combined specimens with frictional-bonded interfaces or joints. Furthermore, this study provides valuable numerical modelling experience for investigating the shear behaviour at the interface between cemented backfill columns and surrounding walls by using the coupled FD-DE method.

Nov 2, 2021

By J. Jeffrey Wagner, Michael J. Bailey, Peter M. Douglass

The Chambers Creek Interceptor Sewer Tunnel project consisted of 2-1/2 miles (4 kilometres) of nominal 9-foot (2.7-metre) O.D. tunnel driven through predominantly glacially overridden soils. Mole-Collucio Construction Company initially elected to drive the entire tunnel with a Lovat TBM. However, this machine could not control the fast raveling ground conditions which developed when the TBM encountered sands overlying very dense, hard glacial till or boulders. As a result, a shield and digger machine was brought in for a 1700-foot (518-metre) long segment. Pumped wells spaced roughly 50 to 125 feet (15 to 38 metres) apart were utilized to dewater about two-thirds of the alignment during construction. Initial support consisted of steel ribs and wood lagging, with a final lining comprised of pre-cast concrete pipe segments grouted in place.

Jan 1, 1985

By Fulton Flick

THE micrography and macrography of aluminum and its alloys present certain difficulties. Many of the difficulties attendant on the micrography have been removed by methods developed during the past few years, notably those of E. H. Dix, Jr.1 The development of grain size in aluminum and its alloys may be equally troublesome, yet comparatively little detailed attention appears to have been given to it. Satisfactory reagents. are available for the development of such structures in ferrous and most non-ferrous metals, but those applied to aluminum and its alloys, i. e., alcoholic or aqueous solutions of sodium hydroxide or hydrofluoric acid are not entirely satisfactory. Hanson and Archbutt,2 in speaking of these two reagents, state that "These two reagents give fairly satisfactory results, but they sometimes produce badly tarnished surfaces from which the surface deposit is difficult to remove." It has been our experience that neither of these reagents is to be entirely relied on for developing structures suitable for study or photography. This means that when the etch fails to produce satisfactory results the, specimen must be repolished, through the 000-paper at least, and then etched with another reagent. This procedure entails a con¬siderable loss of time, and the final results may not be all that might be desired. However, the reagent to be described, although not a panacea for all etching troubles, has improved results so markedly that it is felt that it is worth offering as a grain-size etch generally applicable to aluminum and aluminum alloys. Czochralski3 in 1915 mentioned the application of a solution of 10 to 20 c. c. concentrated hydrofluoric acid in 100 c.c. absolute alcohol, etching in this reagent being followed by dipping in concentrated hydrochloric-acid solution.

Jan 2, 1925

By A. C. Fieldner

"INTRODUCTION In a previous report3 prepared for the American Gas Association, the influence of washing coal on coke properties and on gas and by-product yields was discussed on the basis of answers to questionnaires sent to coke-oven superintendents and a review of the literature on the subject. This review indicated that the elimination of free impurities by cleaning coal improved coke quality by (a) reducing ash and sulphur, (b) decreasing clinker trouble in burning the coke, (c) diminishing cross fractures in the coke, resulting in greater resistance to breakage on handling, and less small coke and breeze, and (d) greater uniformity in chemical composition and physical properties of coke. Washing also reduced the sulphur in coke and gas and increased the yield of gas and by-products per ton of dry coal charged.This paper is supplementary to the previous report and presents some experimental data obtained with Pittsburgh bed coal from Pennsylvania and Mary Lee bed coal from Alabama.ACKNOWLEDGMENTSGrateful acknowledgment is made to F. J. Pfluke, of the Rochester Gas and Electric Cc., of Rochester, N. Y., for the plant test data on screened lump and washed coal; and to Ray W. Arms, Manager of the Coal Cleaning Department, of Roberts & Schaefer Co., of Chicago, for the data on effect of air cleaning."

May 1, 1931

By P W. Wypych

The iron ore industry faces significant challenges in the control of dust to meet emissions regulations and goals, as well as ensuring sustainable operations. This paper describes some of the different techniques and innovative technologies that are being developed and implemented to improve the suppression of airborne dust, specifically through the use of high energy micromist sprays. The utilisation of computational fluid dynamics (CFD) modelling and simulation is identified and described as a key enabling technology for an improvement in dust suppression solutions both from a level of understanding the source and flow of dust emissions, and for the development of new systems that can be used in the iron ore industry. CFD modelling is shown to be effective for modelling both spray dispersion and cross-wind effects, allowing designers to develop high-efficiency dust suppression systems with a greatly improved level of confidence when compared to traditional techniques. New high energy micromist technology is also outlined as a key element in developing high-efficiency dust suppression systems. Experimental results and industry applications are presented to demonstrate the significant improvements that can be achieved in suppressing or reducing airborne dust emissions.CITATION:Roberts, J M and Wypych, P W, 2017. Research into improving the efficiency of water spraying airborne dust control techniques in the iron ore industry, in Proceedings Iron Ore 2017, pp 359–364 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Mani Manimaran, Inna Dymov, Mariam Melashvili, Chris Fleming, Joe O’Day

This paper presents experimental evidence that supports the use of bromine/bromide as a potential alternative to conventional cyanidation for gold leaching. The study evaluated a brominebased lixiviant, Stabilized Bromine, with considerably lower vapour pressure than liquid bromine. Using a rotating device, the rate of gold dissolution was determined at various concentrations of this reagent. The reactivity of pure pyrite, arsenopyrite and chalcopyrite minerals was also evaluated in stabilized bromine reagent. Furthermore, bromine leaching of gold in a number of gold bearing ores was undertaken. Results showed that significantly higher gold recovery can be achieved with bromine than with cyanide when leaching gold encapsulated in sulphides, but bromine consumption was high owing to simultaneous oxidation of the sulphides. The greatest promise for the bromine leach process was with oxidized gold ores. The recovery of gold from oxide ores with bromine was comparable to that achievable with cyanide and bromine consumption was reasonable when leaching was conducted at a near neutral pH of ~6. In the case of oxidized gold ores containing copper mineralization, it is possible that bromine consumption may be lower than cyanide consumption, since there is evidence to suggest that bromine is less reactive than cyanide with copper minerals.

Jan 1, 2014

By E. D. Gardner

From the standpoint of tonnage and dollar value copper is the most important nonferrous metal mined in North America. The opening of copper mines has had an important bearing on the development and settlement of many sections of the continent. The prosperity of many of the mining States or provinces depends directly upon the copper-mining industry. Normally, about 35,000 men are employed in the copper mines, mills, and smelters of the United States. The United States is the most important producer of copper among the nations; more copper is mined in North America than in any other continent, and for many years the United States alone produced about half of the copper of the world. During the last 10 years increasing production in South America and Africa has reduced the relative importance of North America and the United States.

Jan 1, 1938

By Igor Zh. Bunin

A model for developing electric discharges between sulfide mineral (pyrite) particles under high-voltage nanosecond pulses in a liquid medium (water) is considered. A possibility of electrical breakdowns of liquid gaps between particles under nanosecond pulses is shown. This probability and the energy released in discharge channels depend strongly on the sulfide conductivity.

Jan 1, 2010

To maximise recovery by highwall mining, pillars must be designed which are long, slender and of relatively low width-to-height ratios. The strength of pillars with width/height less than 2 depends primarily on the mechanical response of the coal, due to the reduced influence of frictional restraint between roof and floor. A suitable pillar design approach therefore requires a method of estimating coal-seam properties. Experimental studies were carried out to determine ways of reliably predicting the large-scale mechanical properties of coal seams from small-scale test data. The studies led to a method of practical, systematic assessment of coal-seam properties based on measurement of coal rank and seam brightness profiles. The criterion employs the parameters sigma(c), m and s of the generalised Hoek-Brown empirical strength criterion for rock masses. A novel design approach combines the flexibility of modern numerical modelling programs with simple hand calculation for rapid assessment

Jun 21, 1905

By WU Jian-hui

Keywords: metallic material, precursor synthesis, precipitation, nickel, fibrillar powder The composition and morphology of the precursor of fibrillar nanocrystalline nickel powder prepared by oxalate precipitation are characterized by XRD,IR and SEM analysis, and the effects of temperature, nickel concentration, pH, surfactant and drying process on the morphology and the dispersion of the precursor are investigated. By the experiment results, the fibrillar precursor is a complicated nickel salt. The precursor prepared in the of 60~70°C,0.6~0.8 mol/L nickel ion, pH=8.4~8.6 and with addition of PVP surfactant is well dispersive and in fiber form. The powder dried by azeotropic distillation is dispersive.

Jan 1, 2005

By J. P. Brady

A major spontaneous combustion incident occurred in the sealed goaf of the SL3 Panel; Southland Colliery in 2003 resulting in the loss of a longwall and sealing of the mine. The most important issue for the new owners, Yancoal Australia Pty. Ltd, was to effectively manage the atmosphere in the fire affected sealed area. This atmosphere comprised of flammable gases, the products of combustion and excessive levels of oxygen due to pressure differentials across the panel isolation seals with a potential ignition source associated with the residual spontaneous combustion event. The challenges were met in the first instance by the erection of pressure balance chambers with limited success. The problem was not solved until the pressure chambers were pressurized using a Floxal Nitrogen Plant supplied by Air Liquide Australia. Given the success of this approach on a small scale, a higher capacity Air Liquide Floxal Unit was acquired to manage spontaneous combustion at the recommencement of longwall mining operations. This provided the ability to pressurize pressure chambers that were installed in the Maingate Seals behind the face of the adjacent Longwall Block effectively preventing the ingress of oxygen and permitting the goaf to self inert in a reasonable time period. This paper summarizes a new proactive method of mitigating the risks associated with active and sealed goaves. Proactive management of these areas using low flow nitrogen into pressure chambers to maintain a positive pressure has eliminated typical reliance in explosion proof or explosion resistance seals as the primary control.

Jan 1, 2009

By J. R. Thoenen

In the summer of 1937 the authors began a series of time studies of the various processes employed in' the production of crushed stone. These studies, made at quarries situated in the eastern and southeastern parts of the United States, have not been completed, but to make results available to the industry as early as possible, it was decided to publish summaries of the studies made to January 1, 1939, as a series of progress reports. The first of these dealt with power-shovel loading and was issued as Report of Investigations 3461 in September 1939. The second, issued in September 1939 as Report of Investigations 3467, dealt with quarry haulage. The present report discusses analyses of time studies of primary drilling at the same group of quarries. OBJECT Or STUDY Pressure of business problems frequently requires the entire attention of quarry management, and in consequence internal plant economies often are neglected. Also, operating officials absorbed in their local problems are prone to overlook possible economies that would attract attention immediately were they critically examining another plant. The authors felt that technical studies at a number of plants, made by impartial engineers, might disclose opportunities to reduce costs or improve efficiency in internal plant processes.

Jan 1, 1940

By F. J. Plaul

The dominating technologies for steelmaking are the basic oxygen furnace (BOF or LD process, Linz-Donawitz) and the electric-arc furnace (EAF). The main iron input materials for both are liquid iron as hot metal, or solid iron as pig iron, DRI (direct reduced iron), HBI (hot briquetted iron) and scrap. Hot metal, pig iron (i.e., solidified hot metal) and DRI/HBI are virgin iron materials, which have to be produced from iron ore by so-called ironmaking technologies. The family of ironmaking technologies includes three process routes: blast furnace, smelting reduction and direct reduction. Driven by steadily increasing costs of raw materials in the last two decades, the sector has seen a number of new developments in ironmaking technologies, developments based on fluidized-bed technology. The main advantage of a fluidized-bed technology is that fine iron ore can be directly charged to the process without prior treatment; it does away with agglomeration and its concomitant cost, a step practised in blast-furnace, COREX® and MIDREX® processes. With Posco of South Korea, Siemens VAI Metals Technologies has successfully developed the FINEX® process, a smelting reduction based on the direct use of iron ore fines to produce hot metal. The key technology is the four-stage, bubbling fluidized-bed-reactor system, in which fine iron ore is reduced to DRI fines in a countercurrent flow with a reducing gas generated by coal gasification. Beside surveying the current state of the art, this paper discusses the technological principles of smelting-reduction and direct-reduction processes. The status of FINEX® and the outlook for further developments are described. Crucial to the successful development of the new ironmaking technologies for the direct use of fine ore was the scaling up of the fluidized-bed reactor system, which demonstrated new design features.

Jan 1, 2009

By Amanda Elioff

Success of the Gold Line Eastside Ex-tension rail tunnels in Los Angeles, CA has prompted the Los Angeles County Metropolitan Transportation Authority?s (Metro) planning new rail lines to include underground alternatives. The Westside Extension Transit Corridor alternatives include up to 27 km (17 miles) of subway to be constructed in soft ground. The routes will require construction in Los Angeles? ?potential methane zone,? which was not considered for subway construction until recently. Slurry face tunnel boring machines (TBM) will likely be specified.

Jan 1, 2009

The works of Metal Manufactures Ltd are situated at Port Kemblam NSW, within a few hundred yards of a deep-water harbour. At present they occupy about 26 acres, and ample provision has been made for future extensions. Rail connection exists between various parts of the Works and the main South Coast Railway, the harbour jetties and the adjacent copper refinery of The Electrolytic Refining and Smelting Co Ltd. A plan of the works is shown in Fig 1.The company was incorporated in March 1916, and commenced production of copper wire in June 1918. Early in 1920, tube manufacture was undertaken, followed by telephone cable mnufacture in 1923. Today the Works consist of five principal sections: Founrdy, Tube Factory, Wire Factory, Cable Factory and Case and Drum Factory. Whilst the last four are engaged in producing the finished materials for despatch from the Works, the first-mentioned is engaged in producing copper, brass, and other non-ferrous billets for use in the Tube and Wire factories. In addition, there are Engineering and Metallurgical Departments supporting the manufacturing sections, and in these, as well as in all other sections of the Works, extensions have been carried out from time to time to provide for increased output and new types of products.

Jan 1, 1938