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By G Boyd

The Nokomai Gold Mining Project commenced production in January 1992. The Project continues a history of mining in theNokomai Valley which extended from 1863 to 1942. L & M Mining Limited have held interests in the valley since 1980. In 1990 the Nokomai Joint Venture was formed with the Hore family, the owners of Nokomai Station, to mine a large alluvial gold resource in the valley. The mine is located adjacent to the Mataura Brown Trout fishery and required extensive environmental studies prior to granting of permits. The mine is budgeted to work for 20 months, processing 460 000 m3 of wash material. During this period, contract miners, Downer Mining Limited, will move in excess of seven million cubic metres of overburden from the deposit.

Jan 1, 1992

Detailed investigation was carried out on the dephosphorization of a number of phosphorus-rich manganese or samples of India by leaching with dilute sulphuric acid. Various process parameters like concentration of acid, liquid-solid ratio, temperature of leaching, time of leaching, and particle size of the ore were studied in detail for the three samples of manganese ore from central India, and optimum values were worked out on a laboratory scale. Preliminary studies show that certain ores which are not easily amemlible to appreciable dephosphorization by leaching with dilute sulphuric acid can be made amenable by :roasting to 700-900°C before leaching.

Jan 1, 1974

By D Craw

Sulphur-rich minerals such as authigenic pyrite (FeS2) are commonly associated with coal mine workings. Metallic elements such as arsenic (As), copper (Cu) and zinc (Zn) are enriched in the pyrite relative to their concentrations in the surrounding environment. Exposure of pyrite and coal to air and water results in a series of oxidation and hydrolysis reactions that are commonly catalysed by species of Thiobacillus bacteria. These reactions lead to a lowering of the pH in the drainage waters (acid mine drainage, AMD) and subsequent mobilisation of trace metals in environmentally significant concentrations. This study assesses the spatial distribution of As, Zn and Cu concentration in water in relation to pH and Eh (redox potential) downstream from the tailings at the Wangaloa opencast lignite mine in southeast Otago. This mine was abandoned in the late 1980s due to a decrease in the economic viability of mining the lignite. The area is showing the characteristic symptoms of AMD, which is detrimental to the health of several Pinus radiate growing on some of the tailings. The pH of the drainage waters can get as low as 2, and in some instances, lower, but it returns to near neutral (pH 6.5) up to 200 metres down stream from the base of mine waste piles. It is well documented that the atmospheric oxidation of pyrite is catalysed microbially, causing a substantial decrease in the pH of the drainage waters. Acidification is then counteracted predominantly by natural abiotic remediation processes occurring downstream.

Jan 1, 1999

Thickener Modelling - Incorporating Shear Effects

Sep 13, 2010

Alluvial gold mining is thriving in the Yukon Territory and Alaska. The scale of many operations is similar to those in New Zealand but there is greater government support for research and test work. As a result a great deal of information on equipment for the recovery of alluvial gold has been obtained. This paper is a review of the information with the aim of making relevant data available in New Zealand.

Jan 1, 1989

Nowadays, technology has improved to extract dimensional stone blocks at quarry sites and also to process these at processing plants for making slabs and tiles. In the process of quarrying and processing, performance evaluation of machinery is very important to achieve optimum output at minimum cost with improved technology. Cost analysis of improved technology includes parameters such as manpower, energy consumption, tool consumption, depreciation, maintenance and also others. The chainsaw machine with long boom and rail in marble quarries and multi-diamond wire saw machine for slab making from granite blocks at processing plants have recently been introduced in India. Thus, a study was carried out under a research project on these machines to assess their suitability. In this paper, performance evaluation and cost analysis of chainsaw and multi-diamond wire saw have been carried out with existing machines on the basis of research findings.

Dec 6, 2010

Two significant TBM boreability predic- tion models are outlined. Predicted advance rates are compared with actual advance rates taken from twenty case histories. The results show that a simple low cost method that uses one machine parameter and one rock parameter compares very favourably with a high cost sophisticated method which also includes information regarding discontinuities in the rock mass. The effect of rock texture on drillability is also examined. A method of quantifying rock texture has been developed and is outlined. Experimental results show that the developed TEXTURE COEFFICIENT returns highly statisti- cally significant correlations with drilla- bility data in a wide range of rock types.

Jan 1, 1987

As far as is known at the present time, important ore occurrences at Mount Isa are restricted to the Urquhart Shale. These occur at Mount Isa itself, and some 13 miles north along strike at the Northern Leases.The primary silver-lead-zinc and copper orebodies occur as adjacent but discretc entities in lithologieally distinct host rocks. The copper orebodies occur in an envelope of "Silica Dolomite", whereas the silver-lead zinc orebodies occur in shale typical of the Urquhart Shale in general.At both Mount Isa and the Northern Leases, secondary lead orebodies occur at thc surface representing primary stratiform silver-lead-zinc sulphide accumulations in the fresh rocks at depth.Secondary copper orebodies are known only at Mount Isa, where they have formed in favourable environments, but unlike the secondary lead orebodies, not in the positions of the former primary mineralization that gave rise to them. The secondary copper is localized in shale remote from the point where the copper was released into solution by weathering. It was derived from very low grade fracture fillings and disseminations of chalcopyrite in the outcropping or suboutcropping crest of the "Silica Dolomite".Primary silver-lead-zinc orebodies arc oxidized without significant transport or secondary enrichment, but secondary copper orebodies arc characterized by considerable transport and extreme secondary enrichment.The original water table stood at approximately 1,150 ft (mine datum) and for the majority of the mine area controlled the base of complete oxidation fairly closely.An oxidized zone approximately 175 ft deep is general in the Urquhart Shale.Structures affecting ground conditions have influenced oxidation and leaching of the silver-lcad-zinc orebodies, and have had effects vital to the formation of secondary copper orebodies.

Jan 1, 1966

The addition of cement to underground backfill at The Zinc Corporation, Limited and New Broken Hill Consolidated Limited, Broken Hill commenced in 1967. A deterioration in metallurgical performance at each concentrator occurred as a result, with increased loss of lead and zinc to residues. Investigations to determine the reasons for this problem and methods to counteract it have been undertaken. This paper outlines the effects of cement on lead-zinc beneficiation at Broken Hill and presents an interim report on attempts to overcome the metallurgical deterioration.

Jan 1, 1971

THE irregularity of the Mount Morgan ore body presents problems other than those for mining only. For irregularity of outline is coupled with irregularity of grade, and the ore varies so rapidly from profitable to non-profitable, and from highly siliceous to highly pyritic, that the task of estimating quantities and values of ore reserves is manifestly rendered a difficult one, while the actual disposal Of the broken ore demands constant supervision.Four classes of ore are handled. The oxidized ore, cheaply mined and cheaply treated, is obtained by quarrying from the top of the mountain. Below the 315-ft. mine level (measured from the original summit) sulphide ore comes in, and this is divided into siliceous sulphide ore (too siliceous for economic smelting), sulphide ore suitable for smelting, and ore too poor either to be smelted or to be treated by wet process with the siliceous ore. It is with these three latter descriptions of ore that this paper principally deals.Although the output from most stopes in the mine may usually be presumed beforehand to be either smelting or wet-treatment ore...

Jan 1, 1910

Advanced Jig Separation of Shredded Plastics The authors have reported that the RETAC jig is very useful in separating relatively low density particles such as plastics, and demonstrated that highly efficient jig separation of plastic components in discarded office machines is possible in pilot-scale tests. To further improve the separation efficiency, a hybrid jig (RETAC jig with air bubbler under the particle bed) which can separate plastics having similar specific gravities using differences in wettability produced by a pretreatment, and a reverse jig (modified RETAC jig for plastics lighter than water) were developed. This paper reviews the separation of shredded plastics using advanced jig separation technology (RETAC, hybrid and reverse jigs). Wettability control of the plastics for the advanced jig separation is also reported.

Sep 13, 2010

Laboratory scale flotation tests were done on mineral hematite and aspecular hematite ore using oleic acid and sodium oleate as collectors. The mineral hematite floated strongly in the neutral pH region, with an increased pH range of flotation at higher oleate additions. Concentrates with sufficient hematite grade to meet the paint pigment specification were produced using oleic acid and sodium oleate as hematite collectors on the specular hematite ore. Hematite recoveries of 70 per cent at 60 per cent Fe grade were obtained using stagewise roughing. The interaction between hematite and oleate was confirmed as chemisorption but the exact mechanism could not be determined, as two independent phenomena can be used to explain the fact that the pH of maximum grade increased with increasing oleate addition.

Jan 1, 1999

ABSTRACTRock stresses can be modified by physicochemical processes.If rock pores allow the ingress of water and oxygen, but are not large enough to permit the exit of larger molecules of weathering products, anomalous rock pressures develop. Rock masses may also be subjected to osmotic pressures developed as water diffuses into pores and joints filled with saline water. Anomalous rock pressures may also develop as gels filling pores undergo syneresis and as salts crystallize from pore solutions.

Jan 1, 1968

Application of Natural Zeolite for the Removal of Diethylenetriamine (DETA) and DETA-Metal Complexes from Flotation Process Water

Sep 13, 2010

By C Rizzardi, M Callahan, J Mahon

Henderson Operation’s underground molybdenum mine has been in production since 1976. Since that historic date, more than one billion pounds of moly has been produced, and over 120 Mt of ore extracted from three different levels and many different panels. The safe and successful operation of Henderson has been, and will continue to be, dependent on utilising an increasingly sophisticated fleet of equipment, advanced designs, innovative mining techniques, best practices in maintenance processes, improvements in crushing and conveying systems, and most importantly, the training and mentoring of the underground staff. These ‘professional mining technicians’ have been essential in the safe and efficient operation and maintenance of the underground mine and convey systems, and will drive the continuous improvements needed to keep Henderson competitive in the growing global market.CITATION:Callahan, M, Mahon, J and Rizzardi, C, 2016. Development of the professional mining technician – Henderson’s underground mine continuous improvement program, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 161–166 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

(Published by courtesy of the Great Boulder Pty. Gold Mines, Limited)1. INTRODUCTIONThe faults described in the following paper are of a somewhat unusual character, and have presented a serious problem both in the development and mining of many ore-bodies on the Eastern side of the Boulder Belt. They are mentioned only briefly in the literature of the field, but were observed by, both Stillwell (1)t and Gustafson (2), and have been studied by other geologists and operators in various parts of the "Belt." Their effect on the lodes of Hamilton Section, Great Boulder Mine, was described by King (3) in 1937, and, during recent years, they have been encountered in most of the Great Boulder workings extending east of the Boulder Dyke.Although this paper is based mainly on a study of faulting and development problems on the Great Boulder mine, the general conclusions reached may be applicable to the solution of similar faulting problems in other mines throughout the field.In order to arrive at a clear understanding of the somewhat complicated relationships which the east-dipping faults bear to the lode systems it will be necessary to give a brief outline of the salient geological and structural features of the "Belt" before proceeding to describe the faults themselves.2. GENERAL GEOLOGYThe most recent descriptions of the geology of Kalgoorlie are those by Stillwell (1) and Gustafson (2) and the reader is referred to these as representing the basis of current knowledge of the geology of the field.The Boulder Belt is comprised of a central core of altered quartz dolerite which is flanked on either side by fine grained greenstones and lavas, usually referred to as the calc schists. Down the centre of the quartz dolerite mass there is an infolded bed of slate (2, p. 105) which has been intruded in lit par lit fashion by albite porphyry; the composite body of slate and porphyry so formed is known as the "Boulder Dyke." Numerous smaller porphyry dykes intrude both the quartz dolerite and the calc schist; these vary in composition and range from chloritised hornblende porphyrites to albite porphyries.The whole of the rock assemblage has been subjected tG a considerable amount of folding, faulting, shearing and fracturing, the greater part of which took place before the formation of the lodes.

Jan 1, 1941

On the 17th November, 1964, a new No., 2 lead blast furnace was blown in at Port Pirie. The furnace departed from previous designs by incorporating a centrally located continuous tapper for both lead bullion and slag. The use of a central tapper permitted a simple and effective layout for the handling of both products. Considerable development was necessary to bring the furnace to its present level of efficiency. Units vital to the continu- ous operation were developed to allow quick replacement, thus ensuring high time efficiency under varied operating and maintenance conditions. The furnace was designed with the following objectives in mind, 1. increased crucible life, 2. elimination of oxygen for slag tapping, 3. higher temperature slag for fuming operations-, 4. less operator skill needed, 5. reduced tapping tool consumption, 6. elimination of settler skull and scrap lead, 7. better control of blast air distributi.nn. And

Jan 1, 1975

The mercury, gold, silver, copper, lead and zinc values of soils over altered and mineralised rock were determined to establish the potential use of mercury as an indicator element in geochemical prospecting. The results are presented to show that mercury can be used successfully in prospecting for precious metal mineralization in the Thames-Waihi area.

Jan 1, 1979

Theories of ore genesis. have both practical and philosophical application-practical in that they influence our search for new ore bodies; philosophical in that they provide a test for our theories of petrogenesis-and our ingenuity.For example, the theory of granitization requires an explanation of ore genesis compatible with the general concepts of granitization.Our understanding of some processes of ore formation, such as supergene enrichment, or the formation of residual lateritic iron ores, is so complete as to permit of nq controversy.For other ores, like the oolitic iron ores of England and France, and elsewhere, or the segregations of chromite or ilmenite in basic igneous rocks, the broad principles are generally agreed on; dispute is limited to details of process.But for a wide range of ore deposits there is no such agreement. Completely incompatible hypotheses are advanced to explain' identical facts, and we have difficulty in finding new facts or criteria that will distinguish unambiguously between them.In thinking about such ores, a co:n;venient starting point is provided by Schneiderhohn's (1953) fourfold division of ore deposits:1. The secondary hydrothermal ore deposits occurring in Mesozoic-Neozoic cover strata of Europe.2. The "regenerated" younger ore deposits in Alpine type mountain chains.3. Post-Cambrian primary hydrothermal ore deposits.4. Ore deposits of the PreCambrian shields.To these we may add a fifth group:5. Stratigraphically controlled sulphide deposits.

Jan 1, 1956

IN this paper an attempt is made to describe the sluicing operations on the tin fields of north-eastern Tasmania. No claim is made to completeness, for much of the ground has already been covered, and nothing is to be gained by needless repetition. On this account some portions of the subject have obviously received but attention in order that others may be rather more fully dealt with; for instance, referring to the accuracy of various methods of valuing alluvial deposits, particulars of efficiencies, and water duties on both overburden and drift; also, the system of recording water distribution, &c. The plans of the tin-streaming shed, sluice and feed race, and overburden tail-race represent types of the most modern design.GEOLOGY. The principal alluvial dcposits being worked at the present time are situated either in the ancient or modern bed of the Ringarooma River or its tributaries. This river flowed in a north-easterly direction, receiving numerous tributaries on either bank...

Jan 1, 1910