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By S Marsters

Imerys Tableware New Zealand Limited has mining rights to four deposits of halloysite, which are located about 203 km north of Auckland, New Zealand. These primary deposits were formed by the hydrothermal alteration and weathering of rhyolite domes. Halloysite clay is currently being mined from two of these deposits and then processed for export markets. From humble beginnings in the mid 1950s, the Northland halloysite was processed initially for paper filler markets and then for higher value tableware and technical ceramic niche export markets. The paper will briefly cover the geology and processing of halloysite and then examine the history of New Zealand China Clays Limited, now Imerys Tableware New Zealand Limited and then look to its future as part of global industrial minerals company, Imerys.

Jan 1, 2002

By A Sellgren, M R. Carstens, R Visintainer

There is a wide variety of industrial pastes or non-settling slurries pumped in mining, dredging and reclamation projects as products, refuse and tails. The types and/or names of some of the common ones are alumina red mud, phosphate clays, tar sands mature fine tails, tar sands (CT) consolidated clays and fly ash. The pipeline performance or friction of these varies dramatically with the type, its concentration and the particulars of the actual slurry making it difficult to select pumping equipment and to design associated pipelines. The GIW Hydraulic Laboratory in Grovetown Georgia has tested a number of these slurries over the last 30 years for various mining customers. Where available in the public domain and/or where permission has been obtained, the results of those tests are presented in this paper in a form usable for pipeline and pump system designers and users.

Jan 1, 2005

By G L. Simmons, K M. LeVier, R Kappes

The low potential hydrophobic state of pyrite in amyl xanthate (PAX) flotation with nitrogen is of particular interest with regard to the N2TEC flotation technology currently being used for the recovery of auriferous pyrite at NewmontÆs Lone Tree Plant in Nevada. Initially, the N2TEC system had been found to operate satisfactorily, but cyanide in the flotation mill water appeared to be responsible for a loss in pyrite recovery. This supposition was confirmed with laboratory experiments, and a program was initiated to study flotation chemistry variables by electrochemically controlled contact angle measurements. Experimental results show that activation of pyrite in such cyanide solutions can be achieved more effectively with lead than with copper. Subsequently, based on these fundamental studies, significant improvement at the Lone Tree Plant was achieved by lead activation, in which case the recovery increased to expected levels. The effect of activator is particularly significant not only with respect to pyrite depression by residual cyanide, but also with respect to collector (PAX) consumption and the initial state of the pyrite surface. Experimental results show the importance of the pyrite surface state and the rather interesting features of the activation process.

Jan 1, 2005

By Henderson J, Ward RG

Dissolved oxygen has been measured directly using a rugged, reliable, accurate electrochemical probe system developed for steelworks application by B.H.P. Central Research Laboratories. Furnace measurements show that the steel is generally supersaturated with oxygen and that oxygen contents vary considerably from heat. to heat. Ladle measurements also show considerable heat-to-heat variations. Analysis in terms of ladle deoxidation chemistry differentiates between carbon monoxide controlled and manganese silicate controlled oxygen levels. Deviations from these levels are sometimes due to aluminium present in other added ladle alloys but in some cases the plant applicability of laboratory derived equilibria is questionable.

Jan 1, 1972

By Adranyl W. W

Sub-level caving with bottom ore drawing has gained wide acceptance in rich, soft, low magnetic iron ores because it provides moderate ore dilution and ore losses. The main problem here is the high rock pressure exerted on sub-level drives situated in the sub-level sill pillars. To reduce this effect, the ore block is divided into panels. This paper illustraes the method of determining the maximum panel width providing low maintenance cost of sub-level drives.

Jan 1, 1995

By Gordon DM

SUMMARY Tyres account for 25-30% of the operating costs of large capacity haul units as used in open-cut mines. Tyre operating costs can be substanti- ally reduced and often contained in real terms by applying knowledge that is now available. This paper describes certain specific advances in tyre management, namely batching, bias adjustment, cumulative plotting and the so-called "pressure-temperature" system of tyre pressure control, originated on the Mt. Newman Mining Company's Newman minesite, and discusses the contribution that each has made to improving tyre management and reducing costs. INTRODUCTION Tyres are a significant cost in mining. Tyre costs make up between 25% and 30% of the operating costs of large (i.e. 100 tonne and larger capacity) open-cut mine haultrucks. On a large mine this tyre cost may amount to several millions of dollars each year. It is a fact that through careful

Jan 1, 1982

By S Porter, R Woodall, N Weeks

Nelsen, Porter and Wilson (1996) provided some preliminary concepts for the design of the Melbourne City Link tunnels. At that time, the City Link project was in the early design phase whereas now it is nearing completion. This paper provides details of the actual design adopted for the various sections of the tunnels as well as some commentary on the design process. The tunnels form a critical element of the project and the design of both driven and cut and cover tunnel sections is a significant factor contributing to successful project execution. Geology, hydrogeology, site constraints, traffic management and program were important design inputs. Design for the cut and cover sections in particular varied significantly in response to these differing inputs.

Jan 1, 1999

By S J. Kim, S W. Kim, L Tomas da Rocha, S Jung

Al2O3 has been regarded as a harmful gangue component in iron ore, especially causing reduction degradation in industrial sintering of iron ore. The current study aimed to utilise low-grade iron ore containing high Al2O3 content in sintering process. In order to counteract the adverse effect of Al2O3 on reduction behaviour of iron ore sinter, mill-scale and calcined dolomite were chosen as FeO- and MgO-bearing materials. Firstly, mill-scale was added to high Al2O3 sinter and addition was optimised as 10 wt per cent, then calcined dolomite was added further. Magnetite and magnesio-ferrite were identified as the major phases in iron ore sinter when adding mill-scale and calcined dolomite. As the dosage of calcined dolomite increased beyond 4 wt per cent of in sinter mix, unreacted MgO particles were observed, which is ascribed to the limitation of MgO dissolution into magnetite matrix. Both mill-scale and calcined dolomite were effective in improving compressive load and Reduction Disintegration Index (RDI) of iron ore sinter although its reduction degree was highly decreased. The addition of both FeO and MgO-bearing materials to high Al2O3 sinter has a potential to improve the sinter quality, also contribute to the recycling of industrial by-product. However, the amount should be optimised in views of phase development and deterioration of reducibility.

Jun 19, 2024

By K Paki, K Parker, J F. Dupont

The Mount Charlotte grinding circuit at KCGMÆs Fimiston mill was recently equipped with three 650 mm CAVEX cyclones in order to improve the overflow P80, reduce the fines bypass to the underflow and improve the underflow density/recovery of water to the overflow. After the first two sets of surveys were conducted air core boosters (ACBs) were installed on the 650 mm CAVEX cyclones in an attempt to further increase their performance. JKTech was approached to assist with the examination of the data obtained from the surveys; this data was intensively modelled to determine, to a high degree of confidence, the impact the changes to the cyclones had on the classification and the benefits to the plant. This paper outlines the outcomes of the trial and the methods used to determine those outcomes.

Jan 1, 2007

By R Heath, P Rose, L Coetser

A sustained eight-year major research effort has been undertaken in South Africa to develop integrated passive water treatment systems for the sustainable removal of sulfates, while simultaneously addressing the removal of metals and acidity. The research effort addressed the problem both at a fundamental science level and at the more empirical pilot plant level. Whereas there are numerous anaerobic sulfate reducing reactors in operation on mine waters that remove some sulfate together with metals and acidity, these are typically plagued by low sulfate removal efficiency and gradual reductions in overall reactor efficiency with time. The South African research effort has focused on understanding the fundamental microbiological and biochemical reactions that occur in anaerobic reactors filled with lignocellulosic material and subjected to high sulfate water. Hypotheses have been developed that differentiate the reactions occurring in such a reactor into groups that should be individually optimised and these hypotheses have been verified through rigorous laboratory and pilot scale studies. The results of this research are incorporated into a patented multi-stage integrated passive treatment system that is capable of sustained high rate removal of sulfates, metals and acidity.

Jan 1, 2003

In any strip coal mining operation the aosL important single operating unit is the dragline. Because the capital and operating costs of a dragline are high, it is desirable to operate these machines at their maximum efficiency. Thiess Bros. Pty. Limited operate a Bucyrus-Erie 1350 Walking dragline at their Callide coal mine. The operating conditions at the Callide Mine are different from those of other coal mines situated in Central Queens ,nd. The topography is rugged, the coal seam is thick, and the overburden is hard and inter- HH,inded. Several different operating techniques for a large dragline working under these con- ditinns arc discrossmd it tt

Jan 1, 1978

By V Kainulainen

Sandvik Tamrock Corp has developed an underground rock flow simulation tool OPTIMINEÖ which is a direct simulation tool for matching suitable technology in rock material flow for underground mine layouts and production requirements. The tool gives the possibility of determining intersections, limitations and critical points in the layout and working procedures at an early stage of a new mine/mining area planning process. The tool combines the supplier machine knowledge with operational know-how and mine environment. It can be used for identifying the effect of an individual incident such as the effect of one additional turn in a continuous loading cycle to the daily capacity. This paper discusses the way the OPTIMINEÖ simulation tool operates, the benefits and restrictions, and reviews how it simulates some example cases and how the mines benefit from the tool in maximising the performance and optimising the mobile fleet, scheduling work and fine-tuning the layout.

Jan 1, 2000

As a number of underground fires have unfortunately happened in the Broken Hill mining district, the writer trusts that a paper dealing with such a subject may prove of interest. To simplify matters, the subject is classed under three mainheadings- I Origin of fires; II Methods of subduing them; III Precautions to minimize the risk of their occurrence.Underground fires may be started in three ways - arson, spontaneous combustion, or carelessness.With regard to the first-mentioned cause, direct evidence is usually lacking to prove that any fire has been caused maliciously; Though definite proof of spontaneous combustion having been the cause of a mine fire has not been brought forward, nevertheless it should be considered, especially in the case of sulphide ore bodies of a more or less friable nature. The writer has been informed on reliable authority that in an open stope on the...

Jan 1, 1911

By C Lower

An unprecedented, quantitative, deposit-scale understanding of major clay mineral distribution throughout the Yeelirrie uranium deposit has been achieved by adapting the existing HyLogger™/HyChips™ analytical technique to measure resource assay pulps. Spectral analysis via HyLogger™ and HyChips™ systems has previously been used as a small-scale geometallurgical research tool, but never before has it been quantitatively applied to an entire resource sample population for the purpose of developing stand alone block models for major clay minerals. Economic uranium mineralisation within the thin but extensive Yeelirrie?palaeochannel?primarily exists within the transition zone between a groundwater-derived calcrete and the underlying clay-quartz regolith. Early geometallurgical investigations identified that certain clay minerals could be deleterious to the efficiency of the uranium recovery process. Accurate calculation of clay mineralogy from resource assays proved too difficult due to chemical similarities between co-existing kaolinite, smectite and magnesium carbonate minerals. A relatively low-cost, efficient and accurate method of quantitative clay mineral analysis was required to measure over 70 000 resource assay pulps. After initial testing and comparison with QXRD, the HyChips™ 3-1 spectral logging system was implemented as a primary method of clay mineral analysis for the Yeelirrie uranium deposit. The resultant spatial data set allowed the interpretation and geostatistical analysis of geometallurgical domains across the deposit. Clay block models were generated and used in geometallurgical resource calculations to benefit the mine planning process.

Sep 5, 2011

Despite mineral sand occurrences having been noted since the 1970s, the Wemen North Mine is the first operation to commence commercial mining within the inland Murray Basin. The deposit was discovered in the 1990s and, following lengthy resource development, mining commenced in 2001. This initial mine was established as a pilot operation to test the commercial viability of mining in the Murray Basin, with subsequent expansions planned if the mine proves successful. The deposit lies beneath arable farmland close to the Murray River and is hosted by Pliocene marine sands, with a geometry resembling a classical beach strand placer. The operation utilises traditional dry mining overburden removal techniques, with ore mining carried out using a floating dredge and concentrator. This paper looks at the geology of the Wemen North deposit, the mining techniques and challenges as well as grade control practices employed to mine this palaeo-beach placer deposit.

Jan 1, 2003

By Lowder G. G, Cooper R. S, Radke F, Watmuff I. G

During the past five years Amdel has in vestigated metallurgically and mineralogically most of the Western Australian nickel sulphide ores. The mineralogical work has been carried out primarily to assist the metallurgical stud- ies and this paper reviews the application of mineralogical techniques to such ores to obtain information of direct use to the process met- allurgist. The techniques are described briefly and results are given of various in- vestigations of head samples, concentrates and tailings.. It is demonstrated that mineral- ogy has an important role to play in the optim- ization of nickel processing operations.

Jan 1, 1973

While South Africa is well endowed with mineral resources, it is generally accepted that its future will be determined more by the development of its human resources than its mineral wealth. The country has throughout its modern history suffered from an over-supply of unskilled labour and a shortage of skilled and professional manpower. There has furthermore always been an over-reliance on Whites as an internal source of professional manpower, supplemented by immigration wherever possible. Better utilisation of other population groups in professional positions has been hampered by the general lack of education and training among such groups. Although many problems still remain, there are emerging trends which are likely to positively affect the training of professional manpower in the future. The direct and indirect influences that are likely to affect professional training at the macro level include 1. government policy and objectives in respect of manpower education and training, 2. the emergence of technikons as fully- fledged tertiary education institutions, 3. demographic trends in South Africa as they pertain to education, 4. political and statutory developments in the country, 5. industry involvement in tertiary education, and 6. professional registration.

Jan 1, 1986

By Just J, Nguyen G, Dunn J. G, Graham J

A sample of pyritic gold concentrate was investigated by wet chemical and electron optical techniques. Sub-samples were roasted in a laboratory scale fluidized bed roaster in the temperature range 400-700¦C. The calcine was characterised, and cyanide-leached using a standard bottle rolling test. Gold extraction efficiencies varied with roasting temperature. At temperatures of 400 and 450¦C gold ex- tractions of less than 40% were achieved, but between 500-700¦C the extraction had increased to 93--98Z. The surface area of the calcine varied with roasting temperature, reaching a maximum at 500¦C. There was no correlation between the surface area of the calcine and the efficiency of gold extraction.

Jan 1, 1987

Electronic detonators bring a fundamental and radical change to the potential of rockbreaking operations. The immense technical challenge of safely merging electronic systems with explosives has been largely overcome, but a surprisingly difficult obstacle has been to convert users to the much more capable electronic systems, in routine as opposed to exotic applications. Unit cost is probably the main point of resistance. For years papers have confirmed significant improvements in blasting results, feeding through to enhanced bottom line value for the whole operation: much reduced environmental impact, and improved control over fragmentation, muckpile shape and overbreak. In Africa, a number of operations have been employing the technology for sufficient time to see enduring improvements in throughput, control and cost structure, and these improvements have fed through to the planning process: both the cost and the benefits are part of the plan. This has essentially rendered very unattractive the option of reverting to pyrotechnic systems and incurring the penalties previously unseen but now understood to be avoidable. Examples given are of improved throughput at opencast and underground mines, and greatly extended life at an urban quarry. The general experience of management in implementing the technology is that it over-delivers: adopted to solve one particular problem, significant other issues are also addressed. These extra benefits were quite logical, but not at all obvious prior to implementation. Exploring this reality is essential for harvesting the benefits of the technology sooner rather than later.

Jan 1, 2004

n One of the most interesting and economically important developments which has .`taken place- in the Kalgoorlie Field over the past twenty .years is the proved penetration of ore into - caicò schist. which:has been established on the North Kalgurli Mine. 'This is quite extensive, both. laterally and ' in -depth, and has occasioned-,'" ccasioned ' " some madification.of geological thought In the search for additional ore sources:. .Ore has been mined in calc schist almost since the' first major: gold::discoveries-were made,. and the principal 'features of the various types of depos:itl are well covered in the literature ' of the field. ' However, occurrences in caic schist have not-been characterised by the same degree of continuity or frequency as the innumerable lode formations in- the more -favourable quartz dolerite, ' and there has been a tendencyAo regard,them as isolated and discontinuous ore bearing structures, occurring only under very special-- conditions. It is not intended-:to describe the whole' range of caic schist ore occurrences in this paper, but only major controlling structures, whose penetration therein has been definitely established, and in which an appreciable .amount.of,_ore.has, been and is still being. found.. . It is considered that -similar stiiictiires: may present a' major objective for future exploratory work in other parts of the field'.

Jan 1, 1964