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By Robert A. Field

Static-Load Piledriving utilizes a hydraulic push to facilitate the installation of a pile. The pile is not rotated, impacted or vibrated. A smooth pushing force advances the pile incrementally into the ground. Static-Load devices must have a reaction mass to push against. The most simple form of a Static-Load device is a jack; more advanced equipment, such as the Still Worker, also utilizes this approach. This paper focuses on the use of the Still Worker on three challenging projects. In each case, the existing site conditions made it risky, or unattractive, to utilize conventional impact, vibratory, or drilled-shaft equipment.

Jan 1, 1997

By Q. Zhang, J. A. Finch

"Sphalerite flotation in the absence of copper activation at moderately alkaline pH has been observed in laboratory studies. An in-plant test of this observation was conducted at Kidd Creek Mine LTD. using a portable minicell flotation circuit. The results confirm that raising the pH causes sphalerite flotation.The testwork with the minicell circuit is described. The circuit, built around 2, 51 cells donated by the Noranda Technology Centre, was funded by Air Liquide and NSERC. It includes a data acquisition system to monitor continuously dissolved oxygen, pH and Pulp potential.INTRODUCTIONFlotation of sphalerite is normally practised by adding CuSO4 as an activator under alkaline pH. Recently there have been a number of laboratory and plant examples of sphalerite flotation without deliberate addition of cu++ ions (Girczys, 1972; Mukherjee, 1976; McTavish, 1980; Marouf et al., 1986; Mielczarski, 1986; Leroux et al., 1987; Palsson and Forssberg, 1989; Sandoval-Caballero et al., 1990; Zhang et al., 1991).In batch tests, with a sample of Pb/Zn ore from Polaris, Leroux et al. (1987) found that sphalerite became floatable after adjusting pH to 9. 5-11: they ruled out natural floatability or the formation of elemental sulphur on the surface but suspected iron hydroxy compounds were responsible. Sandoval-Caballero (1990) conducted a continuous minicell test at Brunswick Mining and obtained a 44 % Zn recovery and 40.5 % Zn grade concentrate without deliberately adding CuS04 at pH= 10.5. With single mineral studies, Zhang et al. (1991) revealed good sphalerite floatability (over 80% recovery) in pH range 8 to 11 and found that this floatability was related to pH, dissolved oxygen (DO) level and Fe++ species present in the system.To explore further the conditions under which sphalerite can float without addition of CuSO4 , a continuous pilot test using minicells was performed at Falconbridge Ltd., Kidd Creek division. The set-up is briefly described (a more detailed description is given elsewhere in these proceedings) with emphasis on the data acquisition system - dissolved oxygen, pulp potential and pH were monitored continuously. Results of testwork investigating pH, CuS04 addition and gas composition are presented."

Jan 1, 1992

By Tom Meikle

Long tendon support systems provide several challenges when used in-cycle as part of the secondary or primary support cycle. A two-component pumpable resin, Carbothix, has been in development for use with self-drilling rock bolts, but many of the attributes of this new resin system make it ideal for grouting long tendon support systems. While neat Portland cement grouts or polyester resin capsules have been used with long tendon support systems for many years, two-component pumpable resin systems overcome many of the shortcomings in these systems. The two-component systems dramatically improve the set-time to enable mining face advance with fewer delays, enable longer pumping distances, improve quality control, and enhance load transfer mechanisms. This paper describes the key benefits associated with a new pumpable resin and details the Australian Department of Mines and Petroleum department atmospheric testing results and cable load testing completed by Minova personnel to date. It also details the results of the Australian mine site trials and the introduction of these systems into production use.

Jan 1, 2012

Most mines in the Bundamba, North Ipswich, and Rosewood districts of the West Moreton coalfield of south eastern Queensland have installed washing plants during the last five years. Many problems were encountered in their installation, including the small size of washing plant required in many cases, the economical minimum ash content under present and future market requirements, production from a one-product washbox of large and small coal of quality to satisfy both markets, measures to avoid adding unnecessary moisture to the washed slack coals, and excessive middlings in some coals or soft clay in others.INTRODUCTIONIt was fortunate for Brisbane, which was to become the capital of a new State, Queensland, in 1859, and grow into a city of over half a million people by the time of its centenary, that coal was found in abundance almost on its doorstep near Ipswich, the first mine being opened at Redbank in 1843. This was followed by the opening of many more mines in that district and, some 40 years later, in the nearby Rosewood district where high-volatile gas coal was produced (Fig. 1). These discoveries ensured a supply of reasonably priced coal (currently about 85/- per ton delivered) in Brisbane, but the quality is inferior to that of other coals mined in Queensland beyond economic range of Brisbane.Various factors led to an increase in the average ash content of the West Moreton coals during and after the war. Between 1940 and 1952 the gasworks coals rose in average ash from 13 8 per cent to 23·9 per cent and the powerhouse coals from 17·1 per cent to 27·1 per cent. This drift was arrested by the installation of 28 screening and picking plants from 1952 onward, but it became obvious that mechanical cleaning of the coals was essential due to the competitive market for coal and the worsening quality of reserves.

Jan 1, 1963

The following paper on the development of processes for the treatment of crude ore, accumulated dumps of tailing and slime at Broken Hill, has been prepared by a committee of the Broken Hill Branch of the Australasian Institute of Mining and Metallurgy, with the object of recording, in chronological order, the developments of the various processes which have led up to the metallurgical practice of the present day.

Jan 1, 1930

By J. Bennetts

As part of its mission to develop technology that will help increase the supply of critical and strategic minerals from domestic resources, the Bureau of Mines has investigated methods for beneficiating platinum-group metal ores from the Stillwater complex, Montana. This report presents the result of a bench-scale study employing froth flotation to recover a sulfide concentrate containing platinum-palladium values from a mineralized gabbro. Best results were obtained with a flotation scheme utilizing a mercaptobenzothiazone collector and sulfuric acid. Rougher concentrates containing approximately 11 oz Pt-Pd/ton and 90 pct of the metal values in the ore were obtained. Subsequently, cleaner concentrates containing approximately 26 oz Pt-Pd/ton and between 80 to 85 pct of the Pt-Pd values in the ore were prepared.

Jan 1, 1980

By D. Malovichko

Seismic events and pillar failures observed in two platinum mines in the Rustenburg area, South Africa, were investigated. We studied the sources of approximately 300 largest seismic events recorded in 2009. Moment tensors of these events were estimated from amplitudes and polarities of P- and S-waves. The inverted mechanisms contain isotropic implosive components in many instances. Analyses of uncertainty of the moment tensor solutions confirmed the significance of the implosive component in general. Several documented cases of pillar failure were considered in detail. For each of these a seismic moment tensor was calculated from an elastic stress model assuming an instant removal of a failed pillar. The geometries and magnitudes of the theoretical seismic moment tensors are in agreement with the observed (i.e. inverted from seismic data). The results indicate that either pillar failure or fracturing in the proximity of the reef (within a fraction of the dominant wavelength of seismic waves) are responsible for a significant portion of the large events recorded in these mines.

Jan 1, 2012

By Tim O’Neil

The search for precious metals opened up the American West. And Nevada was right in the heart of this development. In the mid-19th century, prospectors seeking gold roamed the hills of Nevada and discovered the ComstockLode. The development of this huge silver and gold deposit began in1859 and was responsible for Nevada’s early entry to statehood. Mining was Nevada’s first industry. In more recent years, the Nevada mining industry has led the nation in gold, silver and barite production. Nevada also produces many other minerals. These include aggregates, clays, copper, diatomite, dolomite, gypsum, lime and limestone, lithium and magnesium compounds, perlite, salt and silica. Even today, Nevada’s mining industry continues to be a major economic force in the state. The mining industry has made more than $10 billion in capital investments in Nevada since 1985. And the value of Nevada’s mineral production last year was about $2.7 billion.

Jan 1, 2000

By P Hunger, H Günter, F Heinicke

High pressure grinding rolls (HPGR) have been used for more than 20 years to grind iron ore pellet feed. Besides coarse comminution (crushing), where HPGR are installed upstream of the ball mill, there are numerous flow sheets where HPGR are used after ball milling and dewatering for re- or finish grinding.There is a clear growing interest in grinding of pellet feed with HPGR during the last few years. In addition to their known advantages of low specific energy consumption, high availability, low steel consumption and improved pelletising processes the lower environmental load (reduced or no water consumption) became a strong driving factor for the application of HPGR in pellet feed grinding.This growing demand increases the interest in better understanding of the HPGR grinding process with fine iron ore concentrates. One of the most important process parameters is the moisture content of the feed material which influences the performance of the HPGR enormously. The HPGR can react to fluctuations of the fresh feed properties to a certain degree by adjusting grinding force and roller speed. Nevertheless, there are limitations by the physics of the compression process and the capability of water absorption by the concentrate. The capability varies for different concentrates and different specific surface areas. This fact has to be considered during engineering of the beneficiation plant.The paper focuses on the influence of feed moisture content on the HPGR performance in view of throughput, increase of Blaine number and process stability on the basis of numerous pilot plant tests, modelling results and industrial experiences.CITATION:Heinicke, F, Günter, H and Hunger, P, 2017. Influence of feed moisture on high pressure grinding roll pellet feed grinding, in Proceedings Iron Ore 2017, pp 187–194 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

Although not fully accepted in South Africa, the Theory of Sampling originally proposed by Pierre Gy is fast becoming the cornerstone of sampling practice throughout the world. The growing acceptance of Gy?s Theory of Sampling in South Africa can be attributed to a number of factors, chief amongst them being the development of a tradable mineral asset market, the promulgation of the Mineral and Petroleum Resources Development Act (MPRDA), the growing number of commercial and academic courses that are offered on sampling, and the regulation of the industry through internationally acceptable guidelines and rules for reporting and trading in mineral assets. The size of the South African minerals industry and the dependence of our economy on mineral production have also meant that correct sampling is of key importance to mineral trade. ISO standards have been the principal guides for producers of mineral bulk commodities who produce to customers? specifications, whereas Gy?s insights have been most readily accepted by precious and base metals producers whose product is sold into metal markets. Understanding of small-scale variability is essential in the precious and base-metal industries, but detailed studies of the effects of heterogeneity have not been as productive in the bulk commodities. Sampling practices at different stages of mineral development from exploration, face sampling and grade control, ore processing and handling, metallurgical sub-sampling, point of sale sampling, and sampling in the laboratory are considered in the gold, platinum, ferrous metal, and coal industries. A summary of the impact of poor sampling in these industries is presented. Generally it appears that poor sampling practice is most likely to erode mineral asset value at the early stages of mineral development. The benefits of good sampling are considered, especially with regard to the financial implications of bias and error on large and consistent consignments of bulk commodities. Keywords theory of sampling, sampling errors, ISO standards.

Jan 1, 2014

By G. I. McPhail

The authors have conducted several investigations into the prediction of the beach profile of high-density tailings and have found that there are a number of important considerations that need to be taken into account over and above the reliability of the beach profile prediction methodology. These considerations relate to the chemistry of the slurry and specifically the influence of pH and flocculation, both of which have a significant influence on the rheology of the slurry at the discharge point. A number of examples are discussed and a potential testing protocol that will assist in assessing the influence of chemistry ahead of the beach profile predictions is presented. A methodology for assimilating the results of the testing into the likely field situation is discussed, and suggestions are made on application of the results in beach profile prediction. The suspected influence of residual flocculation on the stratification

Jan 1, 2012

By Alexander J. Verstraeten

The design and construction of foundations for power transmission line towers present some special problems. This paper describes a system of design and construction for these foundations that was developed in Europe and has attained general use there because of its reliability and cost effectiveness. Transmission line foundations distinguish themselves by having to deal not only with compressive and lateral loads, but with uplift loads and, because of the wind (in some regions earthquakes), with dynamic loading. The construction of transmission line foundations distinguishes itself mainly in the great number of inaccesible locations involved, resulting in extensive geotechnical investigation and logistical problems in moving men, materials and equipment.

Jan 1, 1987

MR. W. E. WAINWRIGHT occupied the chair, and in introducing the lecturer said, on account of the absence of the vice-president, it fell to his lot to introduce the lecturer. Mr. Tennberg, he said, was visiting Australia, and those present might wonder who he was.He understood that the lecturer w~s a reputable practising geophysicist, associated with a reputable company! It was rather desirable perhaps to say that the Institute had made some inquiries with regard to his status. Geophysics was a comparatively newscience, and had suffered several hard knocks in Australia and elsewhere. Most of those knocks had been the result of undue optimism of a number of people who did not understand what they were talking about. It had been claimed that geophysics was a...

Jan 1, 1930

In this, the centennial year of The Institute, it is appropriate that the history of the Institute in New Zealand be recorded. I am indebted to John Dew, compiler of the centenary publication æMining People A Century - Highlights of the First Hundred Years of The AusIMM 1893 - 1993Æ, for many of the early historical references in this paper. In July 1892 the Amalgamated Mining Managers' Association of Australasia held its annual conference in Ballarat, Victoria, Australia, when it was suggested by the delegate from Broken Hill that the time had arrived for the establishment of an Australasian Institute of Mining Engineers. Resulting from this meeting at Ballarat, a Provisional Committee was formed at Broken Hill with the object of forming The Australasian Institute of Mining Engineers having the following objectives. To promote the arts and sciences connected with the economic production of the useful minerals and metals, the welfare of those employed in those industries by means of meetings for social intercourse, and the reading and discussion of professional papers with the circulation by means of publications amongst its members and associates the information thus obtained.

Jan 1, 1993

Factual data about the sedimentation in the Newcastle Coal Measures are presented. Data concerning the total coal measure sequence (isopachs, sand/shale ratio, and total coal thickness variation), data about three coal seams (Borehole, Dudley, and Victoria Tunnel) and data about interseam conglomerate units are discussed.From this data conclusions are drawn about the coal measure environment. The western edge of the coal basin, the Lochinvar Dome, although a high feature, was apparently stable during coal measure time. Despite its height it apparently supplied little sediment to the basin.The northern and north-eastern edge, which was unstable, supplied most of the coarse detritus (including the conglomerates) to the basin. The conglomerates show patterns of fluvial origin but after a period of "normal" variations in pattern they become restricted to two parallel zones evidently tectonically controlled. Deposition of conglomerates is episodic and separated by periods of coal formation when deformation was apparently slight. Formation of each of the three seams considered followed a rather similar pattern- each show development of thick coal around the basin edge and poor thin coal in the "axial" region of the present synclinal structure.Evidence of ill situ formation of some areas of the seams is discussed and periodic deformation of the basin during coal measure time is postulated.The unusual character of this coal basin, in particular the very coarse units, is stressed, despite the presence of many "normal "coal basin features.

Jan 1, 1970

By Russell R. McLellan

As part of an effort to develop new or improved placer mining technology in the Tertiary gold-bearing channel gravel of northern California, the Bureau of Mines conducted investigations at the old Badger Hill placer mine in Nevada County, Calif., to collect data and information regarding drilling and sampling methods and deposit characteristics. Sampling studies involved the collection and processing of 400 tons of large-and small-volume samples from drill holes, underground workings, surface pits, and blasthole rounds. A total of 355 samples averaging 2,296 pounds per sample provided reasonably accurate data for analysis of the gold distribution. These studies indicated that the bulk of the gold is within 40 feet of bedrock in stacked, lenticular zones of cemented gravel that are largely confined to the relatively narrow, meandering course of the deepest portion of the bedrock channel. Drilling studies involved the testing of truck-mounted rotary, buckett and vibratory drills, none of which proved to be a completely versatile tool for sampling quickly and reliably both consolidated and unconsolidated gravel..

Jan 1, 1974

By Rodrigo Toro, Ivan Yutronic N

"The Copper Concentrator Plant of Compañía Minera Doña Inés de Collahuasi (CMDIC) is composed of three grinding lines, the third one being the largest. Due to the capacity feature of the third line, specially its SAG mill, it is a priority that the advanced process control team of the Company deploys a supervisory control strategy that allows this unit to operate in an optimal way, in order to achieve the maximum productivity at minimum cost. It is in this kind of tasks where advanced control applications play a key role in obtaining the best economic profit of the process.The advanced process control team, formed by people from Informatics, Automation and Operations of CMDIC have assumed the challenge of generating the transition from a manual SAG Mill 1011 operation (40 x 22 feet, the largest copper SAG mill of the world), to a fully automatic SAG Mill using a multivariable control strategy instead of a rule based on expert control system (widely used in industrial mining process control applications).Therefore, CMDIC decided to work together with Honeywell APC Team implementing an advanced automatic control strategy for the SAG Mill 1011, using for this purpose a technology called Model Based Predictive Control (MPC), based on a variety of control methods that uses dynamical models of the process, obtained from input/output data, in order to print the process knowledge into a group of mathematical relationships that links the constraints (controlled variables) with available commands (manipulated variables) and measured disturbances.The main objective of the advanced control strategy is to ensure process government, tending to throughput stability and optimization, by the execution of coordinated control actions, proactively avoiding measured disturbances effects and the SAG mill overloading.The most important benefits of using a multivariable control strategy are: the automated operation of SAG mill 1011 (that was manually operated before the implementation of this application), a safer, more coordinated and more stable process operation, achieving through this an increase of throughput and a decrease of specific energy consumption, controlling the amount of oversize material production, power consumption, mill loading, noise and torque. In addition to the operational results, this challenge has consolidated a control team, with the participation of engineers and operators, diminishing the typical implementation time and achieving a greater use of the application in a short time."

Jan 1, 2010

Some of the problems associated with drill core evaluation of alluvial tin deposits and correlation with plant-scale recovery are discussed. Panning churn-drill cores on site tends to undervalue such deposits because of failure to recover completely all the available liberated cassiterite, and secondary gravity processing may also fail to give an accurate determination of potentially recoverable tin. However, by using a combination of heavy liquid separations, x-ray fluorescence analysis for Sn, and normal methods of reflected and transmitted polarized light microscopy, a quantitative assessment of alluvial material can be carried- out. The information obtained may include the liberation characteristics and distribution with size of the cassiterite, the nature and quantities of the various gangue minerals, and the amount of potentially recoverable cassiterite in the material as compared with the amount locked with light gangue minerals and hence difficult or impossible to recover. In addition, an analysis of the efficiencies of the various gravity processes, such as panning, jigging, and tabling, used to determine "recoverable tin" in the alluvial material, can be carried out. A detailed example is given of this type of investigation, in which an assessment was made of a churn-drill core from Uncia, Bolivia.

Jan 1, 1970

By S Vianna, K Caldwell, R Silva, T Olson, D Bell

Studies to enhance the FLSmidth forced air machine through changes in the design, showed important improvements through changes in the number of Rotor blades, stator designs, rotor air distribution and other designs features. The main outcomes from this study highlighted that increasing the number of rotor blades increased the selectivity while decreasing power requirements while stators with slots have better results in terms of recovery, flotation efficiency and selectivity than without slots.Also the rotor air distribution makes a difference in the design when comparing different distribution criteria whilst keeping all features of shape and number of blades etc constant. At the most efficient rotor air distribution design, copper recovery reached one of the highest values while keeping good selectivity. The possible explanation for that is the increase in the pump capacity indicated by the increase in the specific power.It was seen as significant that reduction in specific power for some designs tested compared with the then current standard design had an average of 30% less power consumption.As a result, FLSmidth was able to identify new designs that decreased power and improved recovery, as well as, identifying some designs that specifically improved fine and/or coarse particle recovery.CITATION:Silva, R, Caldwell, K, Bell, D, Olson, T and Vianna, S, 2013. FLSmidth flotation developments - Dorr Oliver machines, in Proceedings MetPlant 2013 , pp 413-430 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

Geological maps, data, and prospectivity analysis relevant to mineral exploration in New Zealand have recently been released. Regional-scale geological mapping is increasingly available for the country through the QMAP 1:250 000 Geological Map of New Zealand programme. Published QMAP sheets Greymouth, Wakatipu, Waitaki and Dunedin cover large areas of interest for mineral exploration companies. The QMAP geological data are also available in digital form for use with other digital datasets using GIS software. Crown Minerals, in cooperation with GNS, have completed two gold prospectivity studies; the first covering mesothermal gold in the South Island, and the second encompassing epithermal gold in northern New Zealand. These studies have defined areas of interest for these two mineralisation types and assembled geological, mineral occurrence and production, geochemical, geophysical, topographic and cultural data into projects for use with GIS software. Included are the results of prospectivity modeling for gold using these data and specific mineralisation models. The prospectivity studies and relevant data are freely available on CD through Crown Minerals and are intended to encourage mineral exploration in New Zealand.

Jan 1, 2003