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By Ibrahim AR

The experimental phosphate mine of abu Tartur has been recently placed into production. Some problems'have been encountered in maintai- ning grade control due to the differences between early block estimates and actual produ- ction grade. An area of 100 km2 is evaluated by using four methods of evaluation , namely polygonal, inverse distance , inverse distance squared and geostatistical methods. The results of calculations are compared statistically with the control values of grade and thickness. The comparison showed that the. kriging technique gave better estimations for the relative ore reserved, while for grades or thickness any of these techniques except the polygonal can be Used.

Jan 1, 1986

This paper reviews the developments in understanding of the entrainment mechanism and its modelling in industrial flotation processes over the last 30 years. Both valuable and gangue minerals in the pulp zone of an industrial flotation machine can be transported through the froth zone to the concentrate launder in the water which must also be transferred from the pulp zone to maintain a stable froth zone in conventional flotation. A size dependent portion of each entrained mineral continues in normal circumstances to the concentrate launder. The size dependency arises because the larger particles are able to drain more successfully from the froth region. Gangue minerals are recovered by a number of mechanisms, entrainment being an important one in many cases. The entrainment mechanism is discussed on the basis of the pattern observed in recovery û size data for minerals. Its industrial implications are discussed and means of minimisation of the importance of the mechanism are also discussed. Various means proposed for mathematical modelling of the entrainment mechanism are also described. The effect of process variables on key parameters in these models is reviewed. Properties of both the pulp and froth zones are discussed where needed and means of taking additional measurements with devices developed over the last ten years are discussed as part of the collection of more detailed data on the flotation process in general and the entrainment mechanism in particular.

Jan 1, 2005

By Lunardi P, Pelizza S

The link between the Lecco bypass and major road SS36 (Italy) requires the construction of a double two-way tunnel (through the mount San Martino carbonatic massif). The tunnel excavating section is about 90 sqm through mount San Martino carbonatic rocks. The mountain sides are unstable and are often the scene of large collapsing landslides (tens of thousand cubic metres). The tunnels are very close to the mountain sides. The use of blasting induces vibrations which may reach the Lecco built-up area. With a view to avoiding such dangers the excavating operations were carried out in two successive stages: - opening a pilot tunnel, whose section is about 10 square metres, by a full face TBM to eliminate the more intense vibrations which are generated by the first opening charges; - successive enlargement by blasting.

Jan 1, 1987

A comparison is made between bord and pillar and longwall coal mining. Longwall mining presents a challenge to raise the level of management and engineering practice. To maintain a competitive position in the world export market, the Australian coal mining industry must continue to use and develop the most advanced, cost benefiting, safe mining systems.

Jan 1, 1987

By Johnson CR, Wilkie G

The aim of the study was to use quantitative mineralogical measurements to predict the processing characteristics of an ore. Samples were taken from a wide range of concentrators processing ores of lead, zinc, copper and nickel. QEM'SEM was used to measure the characteristics of the ore feeding the plant. Concentrate product samples, together with plant operating data were used to give concentrate grade, recovery and grind size information. It was found that the mineralogical measurements correlated well with the metallurgical parameters indicating that these techniques will be very useful for making predictions in feasibility studies and simple plant optimization.

Jan 1, 1989

By Hutchinson IN

In order for the Australian underground coal mining industry to achieve the high productivity rates demanded of it without compromising its good safety record, improved geotechnical monitoring systems are required. One of the main problem areas affecting underground coal mining is the deterioration of previously stable roadways.CSIRO Division of Geomechanics has been working on a NERDDC funded project to develop an instrument to monitor coal mine roof deformation. The instrument which has been developed, Roof Alert, is a self contained, battery powered, intrinsically safe device. It can monitor the magnitude and rate of deformation and give multiple, variable visual alarm signals where preset levels ate exceeded.

Jan 1, 1991

By Milner E. F

Thallium is largely volatilized during sintering in the conventional sinter/blast furnace production of lead. The new direct oxygen smelting processes will force the thallium into the bullion, necessitating a means of removal to avoid contamination of the refined lead. Pilot plant testwork demonstrated that thallium was efficiently removed from lead bullion by treatment with molten zinc chloride. The spent zinc chloride salt was treated in the laboratory to recover lead sulphate, a zinc chloride solution, and a thallous chloride salt containing over 80% thallium. Cominco is installing this thallium process as part of its Trail Lead Smelter Modernization Program which will commission a QSL bath smelter in late 1989.

Jan 1, 1989

The, Ore-bodies.-The ore-bodies of the North mine, North Broken Hill Ltd.; consist of two lenses, connected by a narrow neck of mineralized country. They pitch at an angle of 40° in an easterly direction and dip north at 60° to the horizontal. The southern ore-body, on a horizontal plane, has a total maximum length of 800 feet and in one place attains a width of 230 feet, whilst the northern orebody has a maximum'length of 600 feet and a maximum width of 80 feet.

Jan 1, 1940

By J L. Edwards

High resolution, acoustic scanning technology has emerged in recent years as a powerful wireline tool for identifying the occurrence and orientation of structures and borehole breakout û the latter being a strong indicator of horizontal stress directions. While other wireline techniques such as dip metre and calliper logging can provide some of these data in a fairly rudimentary way, the quality and ease of interpretation of acoustic scanner logs provides a level of detail that significantly enhances the risk profile of the analysis which more than compensates for their additional upfront cost (MacGregor, 2002). As is often the case with such technology it is one thing to generate a data set that describes the attributes of the various features apparent in a log, and another to be able to analyse those data in such a way that their individual and collective impact on mine planning issues can be readily assessed (MacGregor, 2003). This paper describes a process for the interactive manipulation and visualisation of joint and breakout data to enable them to be effectively included in the mine design process.

Jan 1, 2009

By Thompson IR

This paper describes a Client Consultant Relationship and shows how an engineering team created an environ- ment which fosters the development of good, economical and sometimes unique solutions. A major factor in establish- ing this environment was the Client's instruction to the Consultant to "propose solutions which, in the Consultant's considered opinion, best satisfy the needs of the project - not necessarily solutions which reproduce methods adopted elsewhere in the past." The Consultant's experience in other projects and disciplines outside mining has contributed by providing a cross- fertilisation of ideas. The team approach also allows the Client's expertise to be applied positively throughout the design process. These factors and the Client's foresight in providing adequate time for planning, allow the Client-Consultant Team to apply sound fundamental engineering in developing effective solutions.

Jan 1, 1975

Vatukoula is a gold mining township situated at the south-west periphery of a Tertiary caldera which measures 3 miles by 4 miles. Erosion of the caldera resulted in the formation of a topographic depression, called the Tavua basin, covering about 30 square miles. This area, also known as the Tavua Goldfield, has been the site for spasmodic prospecting since the initial discovery of gold in 1932.The mineralization at Vatukoula is typically epithermal with the gold occurring as tellurides, auriferous sulphides, and to a much less extent as native gold. The lodes are confined to three major structures i.e. north-west shears, flatly dipping structures (flat makes), and local shatter orebodies.Within these structures, at least five types of controls are recognized to account for the localization of the oreshoots. The dominant control is structure.The lode structures are related to the overall structural pattern of the Tavua basin. This pattern, which is controlled by the collapse planes of the caldera and a north-west shear system, produced a "shatter block" atVatukoula and elsewhere around the caldera.Structural analysis indicates there are certain areas in the Tavua basin where exploration could be rewarded by the discovery of orebodies with similar controls to those of the productive Vatukoula block.

Jan 1, 1967

By S Furman, M Caccetta, A Hacket, B McDonald, M A. Wells, D Lau

In 2004, the Western Australian Department of Industry and ResourcesÆ Burrup Rock Art Management Committee commissioned a number of independent scientific studies to evaluate the condition of rock art in the Burrup Peninsula near Karratha (Western Australia). These studies are evaluating the physico-chemical aspects of the effect of environmental modification on the visible appearance of the rock art. Because of the cultural significance of the sites, the research approach has been to employ non-destructive testing strategies and work in the field has progressed with respect for the importance of the area. This paper only reports the spectral mineralogy monitoring at each of the sites to evaluate whether changes in mineralogy are observed on rock surfaces. Reflectance spectroscopy is a non-destructive, in situ materials characterisation technique that provides information about the mineralogy. The minerals detected include haematite, kaolinite, chlorite, goethite, gibbsite and manganese oxides. Current results indicate that the surface mineralogy of the rock art has not changed in the last four years.

Jan 1, 2008

By E Kozan

The paper presents new developments of the methodology of open pit coal production scheduling optimisation. They deal with the specific features of the exploitation of single coal seam and utilisation of truck-shovel and dragline systems. A production scheduling optimisation model is developed as a linear programming problem. The objective function maximises the net present value of the mining project under the technological constraints for meeting the demand function of the coal processing plant and effective utilisation of the available production equipment. Both principles of mine planning, coal quality optimisation and waste deferment are incorporated in the model. Results of a case study are provided to illustrate the applicability of the optimisation model.

Jan 1, 2003

By Sweet I. P

Stratigraphic correlations across the Mur- phy Tectonic Ridge are crucial to regional corr. elations between the Mount Isa and McArthur River areas. Recent work in the Westmoreland and surrounding areas has substantiated the earlier general correlations between the Mount Isa and McArthur River sequences. The Mount Isa and McArthur Groups, and their equivalents, remain prime prospecting targets for major lead-zinc deposits of the Mount Isa and R.Y.C. type. A prospective area for Redbank-type copper mineralization is suggested.

Jan 1, 1974

By Slattery T. E

Recent develognents in zinc flotation at the North Broken Hill Limited concentrator are discussed. An outline of the history of zinc flotation and a description of current practice is presented. Installation of on-stream X-ray analysis probes has resulted in inproved metallurgical performance and focussed attention on automatic control. Results are presented of investigations made over the past six years which have led to the formulation of experimental schemes for the automatic control of zinc flotation.

Jan 1, 1983

The mining production rate of two million tonnes per annum at Olympic Dam required greater servicing capacity than was available with the existing Whenan Shaft. To increase servicing capability a Service Decline was constructed from June 1986 to June 1987 extending 2000 m from the surface and linking up with inclining development from the existing Whenan Shaft workings. The decline was used for access of all men and materials during the construction phase of the ore handling system. During production, most mine servicing will be via the decline with hoisting of rock through Whenan Shaft.

Jan 1, 1988

By S Holmes

Solid Energy New Zealand operates the Stockton Opencast Coal Mine, a unique deposit consisting of high quality hard coking and thermal coals. Stockton's uniqueness includes high variability of the shipment specifications, strict quality constraints, minimal stockpiling capacity in the coal transport chain and the variability of coal quality both vertically within the seam and laterally across the deposit. The process of resource proving and modelling results in a high level of understanding of the deposit to allow detailed planning to be undertaken. The use of computer aided mine planning tools is an important component of the mine planning at Stockton. Detailed planning is implemented in the field through selective mining practices and monitoring to minimise dilution and maximise recovery of the coal resource. The quality variability in the coal, the æjust in timeÆ approach of the coal transport chain and markedly varying quality specifications from shipment to shipment requires a large coal inventory and the mine to be driven by quality constraints rather than material movement capacities.

Jan 1, 2003

The economics of gold differs from that for base metals mainly because a large component of gold demand is investment or stock demand whereby the metal is purchased and stored for monetary or anxiety motives rather than fabricated into industrial products.The second major component of gold demand is fabrication, principally into jewellery but also, to some extent, into industrial products.Supply to the Western private- gold market comprises non-Communist mine production, Communist sales (chiefly from the USSR), and, finally, net sales by the Western Central Banks, which have total stocks of about 35,000 tonnes and which are sometimes net buyers as well as sellers.The different components of demand and supply fluctuate from year to year.

Jan 1, 1984

By H Han, X Wang, T Li, D Duan

"In this paper, the reduction and separation behaviour of iron and slag in carbon composite iron ore pellets has been investigated experimentally using an electric resistance furnace simulating a rotary hearth furnace process. The factors that affect the formation of iron nuggets, such as temperature, holding time, molecular ratio of C/O and basicity, are discussed. Results show that the reduction of iron ore, carburisation of reduced iron and the composition and quantity of slag are very important for producing iron nuggets. Through optimisation of process parameters, iron nuggets can be formed below 1300¦C when holding time is 20 minutes, C/O is 0.7 and basicity less than 0.5. This study provides a theoretical and technical basis for iron nugget production.CITATION:Duan, D, Han, H, Wang, X and Li, T, 2013. Iron nugget production technology in rotary hearth furnace process at lower temperature, in Proceedings Iron Ore 2013, pp 363-368 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

By Boontanjai C, Boyapati ER

Reagents used for batch flotation tests were Aeroxanthate-343 & 350, Dow Z-6, & reagent-4037 (from Benambra) as copper collectors; Na2SiO3 & Na2S2O3as gangue depressants; lime & HCl as pH regulators; and pine oil & MIBC (methyl isobutyl carbinol) as flotation frothers. A Denver Sub A flotation cell of capacity 250 gms was used for the batch flotation experiments. Atomic absorption spectrophotometer was used for copper assays and microscopy for selectivity and liberation studies. Melbourne tap water was used throughout the experiments. Unless otherwise stated, the following parameters apply to the flotation experiments: flotation impeller speed - 1300 rpm, pulp density during flotation- 22%, reagents addition - in 4 stages, total conditioning time for collectors - 8 minutes, total flotation time- 9 minutes. A variable quantity of copper mineral collector according to the test in question was added, then conditioned the pulp for 2 minutes. The froth was removed by hand, scraping the full length of the cell at constant depth every 10 seconds. No frother is required for this copper tailing flotation. Four concentrates were collected after addition of collector and conditioning at 2,4,6 and 9 minutes. The pulp volume was maintained at a constant level to yield a constant froth depth.

Jan 1, 1990