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By Roberts T, Firth B. A

A series of flotation experiments was carried out to study the interaction between the parameters of pulp density (mass per cent of solids in feed slurry) and frother addition (on the basis of solid mass feed rate). It was found that certain combinations of pulp density and frother additions caused large losses in yield. The interactive effect of these parameters can be primarily attributed to the total amount of frother added per unit of water. Consequently it is suggested that frother additions be made on the basis of water flow rate. As frother addition increased, in terms of the amount of frother per unit of water, yield increased rapidly but above an addition rate of about 10 g/tone it reached a plateau. Such results correlated well with qualitative visual observations of changes in bubble size and dispersion, with increasing levels of frother addition.

Jan 1, 1984

By J C. Furness, F S. Cannon

Metal casting operations are a significant source of hazardous air pollutants. In particular, high production iron foundries emit significant quantities of volatile organic compounds (VOCs) during pouring, cooling and shakeout of iron castings made in green sand molds. End-of-the-pipeline capture and destruction methods to reduce VOC emissions add crippling costs to foundries. Alternately, the incorporation of advanced oxidants (AO) into metal casting green sand systems has been shown to reduce emissions from high production iron foundries in the US, and at the same time reduce operating costs. Cost savings are driven by the benefits of AO in clay recovery systems. Emissions reductions are the direct result of cascading AO-based reactions taking place in green sand molds. This sustainable greening of the metal casting process is a prototype for the development of other AO and non-AO process-based solutions for sustainable high temperature processing of materials. Fundamentals of AO technologies will be discussed along with the performance characteristics of AO processing systems in the metal casting industry and the breadth of other processing and remediation applications for which AO technologies have the potential to be successfully employed.

Jan 1, 2002

By L D. Meinert

Skarns typically are zoned and the deposit- or district-scale zonation pattern is an important tool in exploration for skarn deposits. Zonation in individual deposits has been described in many publications, and the general zoning patterns have been summarised by Einaudi, Meinert and Newberry (1981), Meinert (1997), and Meinert, Dipple and Nicolescu (2005). Although zonation is present in most skarns as the result of a basic process of transferring heat and fluids from magmas to wall rocks, the specific zoning pattern in each skarn may vary greatly. For example some zones may be missing entirely or multiple zones may be telescoped. Such variations can be caused by several factors including depth of formation, magma composition, timing of the exsolution of magmatic aqueous fluids, redox state of the magma and redox state of the wall rocks. To use zonation as a predictive tool in skarn exploration, all the controlling factors have to be considered. In this study, we discuss some of the factors that may affect the zoning patterns in Ca skarns. Magnesium skarn has dramatically different mineralogy and is not discussed here. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

For the last 4 years political leaders have found a new subject on which they can safely generalize wihout creating opposition. That sub- ject is commodity prices. Since the four-fold increase in OPEC crude oil prices, public atten- tion has focussed as never before on the subject of commodity prices. To advocate stabilizing com- modity prices is akin to supporting motherhood or peace or better schooling. Everyone gives lip service to the concept that stable commodity prices are desirable. It is easier to state the principle than to achieve it. Prices that are stable in terms of one currency may be clearly unstable in terms of a different currency. This has become a troublesome matter since 1971, when the world's leading trading currencies were set free to float in relation to each other. To illustrate: consider copper prices in the interval between the end of 1974 and the end of 1977. During those 3 years, the copper price in pounds sterling on the London Metal Exchange rose by 25 per cent. During that period, however, in terms of the USA dollar equivalent, the price was unchanged. And during that period, in terms of the German mark equivalent the price shrank by 13 per cent while the Japanese yen equivalent f.11 1k

Jan 1, 1978

By C N. Whata

While there is no specific obligation on the part of any applicant to consult directly with tangata whenua (people of the land), recent cases highlight the need to engage in active consultation in order to avoid serious objections and delay, particularly where a proposal may affect the matters referred to in section 6(e) (Waahi tapu/sacred places) and 7(a) (KaitiakitangaiGuardianship) of the RMA.   The Environment Court has shown some sympathy for tangata whenua where waahi tapu and other significant matters of cultural concern are at risk because of a proposed development. There are several practical steps that can be taken to minimise the potential for serious objection including: ò knowing who to contact and how to contact them; ò demonstrating empathy for the concerns of tangata whenua; ò engaging in proactive consultation, for example meeting at a time and a place that is suitable to tangata whenua, and a preparedness to meet the costs of tangata whenua etc; ò demonstrate an awareness of tangata whenua issues; being aware of the types of mechanisms that are available to remedy, avoid etc adverse effects on matters of concern to tangata whenua.

Jan 1, 1997

Recovery Process of Carbon Dioxide with Metal Oxides and Metal Hydroxides

Sep 13, 2010

Twelve years ago, Jeffrey Mining Machinery Division of Dresser Industries Inc. developed the 120H HELIMINER. This machine was the world's first fixed-drum continuous miner and soon became the standard among manufacturers of continuous miners throughout the mining machinery industry. This paper will first outline a brief history of continuous miner development, then discuss significant parameters which are essential to a successful continuous miner design, and finally describe a number of specific applications of Jeffrey continuous miners in a variety of materials, such as coal, potash, iron ore, and trona, around the world.

Jan 1, 1978

Many of the recent major achievements of our industry were visions of our forefathers in the 1800s. Only recently has technology been able to meet the vision of our predecessors. This paper follows the development of selected aspects of tunnelling from the 1800s to present day. It appears that, at the turn of the century, technology is beginning to catch up with our vision and we are able to put our ideas to work more quickly.

Jan 1, 1999

The Martha Mine is an open cut operation situated in the midst of Waihi town which has been operating since 1987. Since then it has produced some 700,000 ounces (oz) of gold and 4,000,000 oz of silver from an epithermal vein system. It was previously worked by underground methods from 1880 to 1952 to a depth of 600 m producing 5 million ounces (Moz) of gold and 30 Moz of silver. The licensed reserves are scheduled to be mined out early in the year 2001. An additional economic resource of over 750,000 oz of gold has been identified which can be accessed by deepening the pit a further 50 m along the main Martha vein. This would extend the mine life to the year 2007. Applications were lodged on 4 July 1997 for the necessary resource consents, discharge permits and variations for the current Mining Licence conditions. The extension project requires approval from the District Council, Regional Council and the Ministry of Commerce. The consent and permitting process is extensive because of the urban setting of the mine. An approach to keep the extension as similar as possible to the current operations was adopted to give the community and authority confidence in the proposed extension. This paper summarises the extension detail and the permitting requirements it has had to address despite the extension being "more of the same". The permitting process has been exhaustive with little recognition of the standards already achieved in protecting the environment which are recognised worldwide.

Jan 1, 1997

By Blockley J. G, Laeter J. R

The history of the Ph-Cu-Zn mineralisation in the orthampton Block of Western Australia has been further investigated. It was hoped that (1) Rh-Sr studies on partially-remelled granulites, wall-rocks to the dolerite dykes, should date the dolerite intrusion, (2) Rh-Sr data on hydrothermally-altered dolerite should date the sulphide mineralisation, (3) Pb model ages on the galenas might provide an independent dating of the mineralisation, in addition to any geochemical information that might be derived. Only the second dating aim was fulfilled, but the Pb isotope data, when combined with the Rh-Sr data, have permitted deductions about U, Th and Pb abundance changes during the regional metamorphism, and about a possible source of the ore Pb. In detail the following has been found. (1) The partially-remelted granulitic wall rocks yield a scattered whole-rock Rh-Sr isochron which seems not to have been reset by the dyke intrusion (age 1037 ± 146 Ma, with initial Sr ratio 0.7171 ± 0·0054, MSWD = 111). This date agrees well with that reported previously for granulites from another locality; together theyestablish the time the metamorphic period closed. (2) The hydrothermally-altered dolerites yield a Rh-Sr whole-rock date 434 ± 16 Ma, with initial Sr ratio 0.7072 ± 0·0029 and MSWD = 31, taken as referring to the time of Ph-Zn mineralisation. This contrasts with a report of much older palaeomagnetic and K-Ar datings of the dolerite (not less than 550 Ma, possibly older) and suggests that neither the dolerites nor their heat have had any connection with the mobilisation of the Pbscavenging solutions. (3) The Pb isotope ratios of galenas from the ores yield a well-correlated regression which is not amenable to any of the model-age calculations. (4) The Pb-isotopic trends negate any genetic connection between dolerite and mineralisation, but the country-rock granulites could be the Pb source. (5) Combination of the Rh-Sr dates and the Pb data in a "simultaneous isochrons" construct permits the inference of major losses from the system during the regional metamorphism, in the order U>Pb>Th, with substantial homogenisation of the remaining Pb. This left a wide range in local UlPb and Th/U among the source rocks which eventually were scavenged by the mineralising solutions. (6) These geochemical deductions are shown to be compatible with previously-published information on the abundance ofU and Th in the Northampton Block granulites, which are thus seen to be credible as source rocks for the ore lead.

Jan 1, 1985

By N Stoitis, L Lien, B Tapley

The treatment of hypersaline waters originating from numerous gold projects within the Western Australian Goldfields region via membrane technology has been assessed. A combination of Ultra-filtration (UF) and Nano-filtration (NF) using Ecotechnol’s modified elements effectively removes the polyvalent ions responsible for the high lime and cyanide consumption as well as the prevalence of scale formation characteristic of gold operations in this region. Through removing up to 98% magnesium, 94% calcium and 99.7% sulfates from hypersaline water with total dissolved solids from 40,000mg/L to 250,000mg/L, Ecotechnol and subsequent independent tests have demonstrated up to an 87% reduction in lime consumption and through the ability to increase the operating leach pH, reduce cyanide consumption by up to 28%.CITATION:Tapley, B, Stoitis, N and Lien, L, 2015. Modified nano-filtration membrane treatment of hyper-saline goldfields water – an overview and benefits to gold plant operation and economics, in Proceedings MetPlant 2015, pp 431–463 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

Progress on this project will be verbally reported and a description given of the main features. A detailed feasibility study was completed in December 1986, and the Joint Venture has issued an Environmental Impact Statement. This was open for public comment until 16 February. Issues presently being considered include economic justification traffic, air quality, noise, marine fauna and flora, visual impact, heritage and construction impact. Detail design and construction is likely to commence in mid 1987, following determination of the above matters.

Jan 1, 1987

Seam gases are the most important atmos- phere contaminants in Australian collieries, their importance increasing with depth; C02 as well as CH4 may be important in intruded envir- onments. The generally high rank of the coal, with low moisture content, makes for abnormal dust production. The other contaminants are introduced and subject to better control, in- cluding products of spontaneous combustion. Due to market situations the generally lower rank and higher sulphur coals more prone to self heating are mined less. Future mining at greater depths should see greater problems with atmosphere contaminants.

Jan 1, 1983

By K Aikawa, M Ito, K Mitsuhashi, Y Ebisu, J V. Satur, I Park, N Hiroyoshi, T Suto

Copper concentration using flotation is becoming more difficult, because of an increase in ore complexity accompanied by smaller grain sizes of copper minerals than usual, requiring finer grinding in order to liberate them. Project Arqueros, located at the mid northern part of Chile, is a copper mine project with an orebody consisting of various sulfides such as chalcopyrite, chalcocite, and bornite. Some of the copper minerals in Arqueros show low floatability mainly because of their fine grain size and resulted fine grinding size, and also because of the complex mineralogical composition. For example, chalcopyrite in Arqueros floats less than the other copper sulfide minerals. In this study we carried out some kinetic flotation tests with the Arqueros ore using a laboratory-scale forced air type flotation machine by varying the regrinding size. The products were assayed and mineralogically analysed to compare the minerals in their flotation behaviour with respect to size classes and liberation classes. The results were compared with a model calculation according to bubble size measurement. From the flotation testing and mineralogical analysis, it was found that copper minerals of the same size and liberation class floated at the same rate even with different regrinding size. At the same time the comparison between experiment and calculation showed that the fine particles of less than 5 µm size floated faster in actual than in the model applied. These results suggested that interactions among minerals of different species and of different sizes had positive impacts on the flotation rate of the fine particles. It indicates that this phenomenon can be applied to improve copper recovery in the project.

Aug 24, 2022

Economic and technical reasons forced the mining industry all over the world to increase the unit size of mineral processing equipment. in large flotation cells, this development leads to problems in areas of air dispersion and keeping solids in suspension. Outokumpu, an operating mining company, designed and developed a mixing mechanism for large flotation cells at its own concentrators and also studied problems related to tank design. Ideal conditions for flotation can only be achieved if the flow pattern created by the mixing mechanism fits well into the tank configuration and the risk of short circuiting is minimized. In large deep flotation cells, four different zones can be found which improve the behaviour of large cells when compared to small cells. Selectivity is increased and in some cases final concentrate grades can be produced from the rougher cell. The largest units have also been used as final cleaners in some installations. When modernizing old plants by installing fewer larger flotation cells, immediate and substantial savings in power consumption are achieved. Additional power savings are made in pumping costs because of simpler circuit design and decreased circulating loads

Jan 1, 1978

A system for rapid on-line determination of weight percentage coal in slurry and weight percentage ash in coal has been developed at the Julius Kruttschnitt Mineral Research Centre, University of Queensland. The gauging system is suitable for use with coal flotation slurries or slurries having a maximum particle size of about 1 millimeter. The system is based upon measurement of gamma ray transmission; radioisotope sources emitting photons of two widely different energies are employed. The inaccuracies of measurement that would normally result from variable amounts of air entrained in the slurry are substantially reduced by pressurising the slurry to approximately 2MPa (300 psi) using a Mono pump. The equipment can be used to make measurements on more than one slurry stream by pumping streams sequent- ially. The system is being tested at the Peak Downs Mine of the Utah Development Company in Central Queensland. This paper describes the theoretical principles of the gauge design, the experience gained to date in the commissioning of the equipment, including the installation of a PDP 11/03 computer, and the progress made in developing satisfactory interpretations of the gauge count-rate output.

Jan 1, 1978

Tougher physical mining and processing conditions as well as economic circumstances are causing many mining companies to re-evaluate the effectiveness of their mine planning. The recent wave of inexpensive computing power provides the engineer an opportunity to go beyond the simple one-off manual mine design and production schedule. The basis of a good mine plan is a good reserves model. Concepts of mine model development are explored. The only advanced computer methods that have found consistent success in optimising mine planning functions are economic pit limits determination and material scheduling. Three pit 'optimisation' methods are examined; the moving cone, the Lerchs-Grossman 3-D graph algorithm, and the new network flow algorithm. A comparison between the methods in terms of total profits generated and computer time involved are made. The results show that both algorithms produced a higher profitability than the simple moving cone, but at much higher execution times. However, the profit increase never exceeded much more than 1 % of the base moving cone case. Finally, a method for the development of long range material production schedules with forward waste planning is presented.

Jan 1, 1989

The Ministry of Commerce has been carrying out an evaluation of the resources of the Northwest Nelson region. In part this was to revisit the issues covered in the earlier proposal to close part of Northwest Nelson to mining under section 24 of the Mining Act (1971) initiated in 1990. In addition, the option of using GIS to integrate a variety of spatial data sets to aid policy formulation could be tested. The Northwest Nelson assessment would be a useful trial. The subsequent national park proposal provided a major impetus to the project and resulted in the scope of the study being broadened to include all energy and minerals resources.

Jan 1, 1993

By V Pfannenstiel

The United States (US) coal mining industry has been working under comprehensive planning, operating and rehabilitation regulatory requirements for nearly 35 years. The public desire for environmental protection during mining and rehabilitation following mining to achieve post-mining land use and sustainability goals has been a major factor and continues to influence the process. Mining companies have evolved operations to achieve outcomes that address the desired goals and regulatory requirements cost-effectively and successfully. Over the 35 year regulatory period, requirements for more diverse topography, specialised revegetation communities, landform stability and assured sustainability have increased and become more complex. These challenges are effectively met by maximising integration of mine planning and operating with the rehabilitation process. Rehabilitation is then implemented in a more timely and efficient manner and with effective results that achieve desired outcomes, commonly with added value. Peabody Energy (Peabody) has taken this approach in its US operations and this paper discusses an integrated approach and illustrates learnings and results with examples from several of its western US operations.CITATION:Pfannenstiel, V, 2012. Integrated planning, mining and rehabilitation for effective results and sustainable land use - A western United States perspective, in Proceedings Life-of-Mine 2012 , pp 219-232 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

The excavatability of the rock mass in a proposed open pit mine at Globe-Progress has been assessed. The rock mass was initially evaluated by determining variations in seismic velocity and by using the Revised Size-Strength Chart. These two assessments should be performed during the feasibility or early investigation stages of a project. A complete rock mass excavatability assessment using a suite of geological and geotechnical properties was then performed using three methods: RMR System; Modified Rippability Rating; and a productivity estimation method. These three methods should be applied during the investigation and design stages of a project. The preliminary assessments show that most of the open pit rock mass is expected to be rippable. The complete assessment differentiates weak, fair and good rock masses within the open pit. Weak rock mass exists along the Globe-Progress Shear zone, located along the northern and eastern pit walls and also in the western pit wall where the Chemist Shop Fault is located are both regions are expected to be diggable. Relatively weak rock mass also exists along the Globe-Progress Shear axial hinge. The Globe-Progress Shear limbs are generally fair to good rock where moderate to hard ripping should be expected.

Jan 1, 1996