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By Yaniuk DW

The sampling of non-ferrous concentrates from trucks and trains has long been carried out either manually or by automatic spears. Very little use has been made of conventional sampling systems for sampling concentrates at transfer points, or cross-belt samplers for sampling from the belt as the concentrate moves along the conveyor.Due to the high value of base metal concentrates and the often extremely heterogeneous nature of the material it is imperative that the sampling procedures adopted are accurate and precise. The basic principle that all particles in the stream have an equal opportunity to be included in the final sample is not fulfilled by accepted traditional concentrate sampling procedures such as the spearing of wagons, trucks or streams. This may lead to significant bias being introduced into the final sample.Consequently, the application of correct sampling procedures, either with conventional cross-stream samplers or the newer cross-belt samplers, is of prime importance.SGS Australia has recently installed a number of cross-belt samplers for the sampling of base metal concentrates both in Australia and overseas. The application of these samplers will be discussed with emphasis on the benefits of their use.

Jan 1, 1976

By Selby DW, Hamill J, Cauley ID, Thomas I, Thornton AJ

The main objective of sulphide flotation in a cassiterite concentrator is to remove sulphide minerals (pyrite, pyrrhotite and sometimes chalcopyrite) from the ore prior to gravity concentration. Tin losses in the sulphide flotation stage account for a significant proportion of the total tin loss. separate studies of the sulphide flotation circuits of Renison Ltd and Cleveland Tin Ltd were conducted to investigate reasons for the tin losses. Sampling surveys were conducted in the rougher-scavenger and also the regrind-cleaner sections of both plants. In both plants, the rougher circuits recover excessive quantities of liberated cassiterite, while recovery of the desired composite cassiterite-sulphide fraction is low. The regrind mills are successful in liberating the composite cassiterite in the rougher concentrate, but at the expense of increasing the proportion of very fine tin mineral. The cleaner circuits recover between 40 and 60% of the cassiterite received, and this is all lost.

Jan 1, 1978

By Roddick F

From its mining lease at the northern end of Cohens Reef at Walhalla in the North Gipps- land mountains, the Long Tunnel Extended Gold Mining Company produced 13,695kg of gold, which at 1982 prices represents a value of about $140 million. In the period 1885 to 1908 the mine was one of Australia's principal reef gold producers, being top Victorian producer in six of these twenty-four years. Prior and subse- quent occupants of the lease produced an addit- ional 160kg of gold. The Extended and the other mines on Cohens Reef whilst contributing importantly to the financial resource of Victoria, were the sole important support for the substantial town of Walhalla that had grown up around them. When the mines closed, Walhalla gradually reduced from a bustling developed town to the present attractive mountain village so favoured by tourists.

Jan 1, 1982

By Coppock BW

Sintering of lead and zinc concentrates is practised by Sulphide Corporation Pty. Limited to provide both desuiphurised lump sinter feed, for simultaneous reduction to zinc and lead in the Imperial Smelting Process blast furnace, and sulphur dioxide gas for sulphuric acid manufacture. From November, 1969 a 20 percent increase in production rate has been obtained through improvements in operating technique. A gradual increase in bed permeability was achieved by modifications to the feed mix conditioning equipment and by improving moisture control. However advantage could not be taken of the higher permeability to increase sulphur elimination because the hardness of the lump sinter decreased. Higher throughput, better quality sinter and more stable sintering conditions were however made possible by simultaneously: 1. reducing segregation and compaction in the sinter bed, by narrowing the discharge opening of the main layer feed hopper, 2. reducing the sizing of sinter returns to give a closer size spectrum of particles in the feed mix, and 3. increasing the sulphide sulphur content of the feed mix to give higher bed Temperatures.

Jan 1, 1972

By Lyman G. J

The volumetric distribution of valuable mineral, or phase, within a set of particles is called the liberation distribution. To optimise a mineral processing plant it is necessary to know the liberation distribution in most of the streams, especially those adjacent to separation devices. Possibly the most common method of analysing ore particles is to section sets of similarly-sized particles. However, the observed sections can appear liberated even if the particle is composite. This means that the 'apparent' liberation distribution can be very different to the 'actual' liberation distribution. This discrepancy is called stereological error. One must then somehow estimate the actual liberation distribution using the apparent liberation distribution. This problem is called the liberation distribution problem and its solution is the subject of this paper. The solution is based on a sorting algorithm which uses geometric probability equations. These equations are based on the assumption that sectioning is isotropic and uniform. Apart from these assumptions the equations are completely independent of particle shape or texture. The algorithm is verified by numerical simulation and experimental methods. For the numerical simulations the correspondence between the actual and estimated liberation distributions is excellent. For the experimental methods, the agreement is not as good and appears to be due to experimental errors.

Jan 1, 1995

By Isobe K, Muchi I, Hsieh YS

Theoretical and experimental studies have been made-to clarify the physical and chemical behavior of the tuyere combustion zone of blast furnace. Gas streamlines around this zone were visualized by the use of the two-dimensional equip- ment. Close agreement between the observed stream- lines and the calculated ones is found. The three- dimensional experimental studies have revealed that there exists a so-called dry zone in the neighbor- hood of the raceway and the trickling liquid be- haves approximately like a continuum. A kinetic model is develdped to describe the behavior of coke combustion in the tuyere zone. The model is based on the reaction kinetics, the differential balances of heat and mass, and the mechanics of gas flows. Regarding-the-axial distribution of gas composition in the tuyere zone, good agreement is obtained be- tween the model prediction and the data observed in a working furnace by the other investigators. Cal- culated results-show that the maximum consumption of coke occurs at the intermediate region of the raceway. For the blowing of oxygen-enriched or high -humidity blast, the position at which the maximum consumption of coke occurs is shifted toward the tuyere nose. Similar effect is found when the par- ticle diameter of coke in the tuyere zone is de- creased. The solid flow pattern around the tuyere combustion zone was visualized by the use of the two-dimensional equipment in which the sublimation of dry ice particles in front of the tuyere was

Jan 1, 1981

By Rospigliosi RT, Krouse HR

The San Vicente stratabound zinc-lead rhythmite deposit, Peru, is hosted in carbonates of the Late Triassic - Early Jurassic Pucara Group. These strata were deposited in a large, shallow water, carbonate platform which extended nearly continuously for 150 kilometers (north-south) in the eastern part of the Pucara basin.The distinctive sulfide-bearing rhythmites occur in three dolomite units which, from bottom to top, include the San Judas horizon with one sulfide-bearing manto; the San Vicente horizon with seven sulfide-bearing mantos including the main ore horizon; and the Alfonso horizon with three sulfide-bearing mantos. The dark gray sulfide-bearing dolostone layers range in thickness from a few millimeters to a few centimeters and contain variable amounts of carbonaceous material, pyrite, quartz, fine-grained sphalerite and galena. They are bordered on each side by selvages of yellow to red-brown coarse-grained sphalerite containing minor amounts of galena. Coarsely crystalline white or gray sparry dolomite is found between the coarse-grained sphalerite layers. Although commonly stratiform and uniform in thickness, the dark layers curve, "pinch out," coalesce, and form "islands" and "peninsulas."Mineral replacement textures, the paragenetic sequence, and presence of sparry dolomite, bitumen, intraformational breccias and isotope data support a hydrothermal replacement origin by metal-bearing solutions that deposited the ore and related minerals in space previously occupied by dolomite and evaporite minerals. The alignment of the Zn -Pb deposits, and at San Vicente the orientation of the mantos, the spatially and temporally associated igneous sills and the tourmaline-bearing sandstone support hydrothermal mineralization driven by a magmatic heat source in a tensional regime.

Jan 1, 1990

During the past 18 months a rock mechanics project has been in operation at Renison Limited. The project was established to identify and investigate key problem areas that would affect future production at the Renison mine. An in-house approach was adopted, using shall compact equignent, to investigate ground behaviour. Information on the rock stress field was considered to be particularly important for an understanding of ground behaviour. A high horizontal stress component exists, which enables large flat dipping spans of hanging wall to be opened up, with support being provided by post pillars. The amount of support provided by these post pillars has been found to be low.

Jan 1, 1982

By Parsons A. E

The application of known pelletizing tech- nology was successful in the agglomeration of zinc concentrate into pellets of minus 6mm siz- ing using fine zinc calcine and sulphuric acid as binder. Subsequent roasting trials conducted in a 0.3 m diameter fluid bed reactor, showed that the pellets satisfactorily withstood hot physical abrasion during fluidization. Fines generation was low and the pellet calcine was hard, possessing excellent handling properties. Results of laboratory scale static pellet sinter- ing tests showed conclusively that the deterior- ation in sinter physical quality experienced with fine calcine was not apparent when the calcine was added to the mix in pellet form. Based on the results of small scale exper- imental work, a one tonne per hour pilot plant was constructed and operated. Several thousand tonne of pellets were produced-for fluid bed roasting in Badische Analin and Soda Fabrik (B.A.S.F.) turbulent layer (T.L.) roasters previously designed for roasting iron pyrite concentrate. Continuity of the T.L. fluid bed roasting operations was achieved when the waste heat boilers were replaced with atmospheric coolers and thus eliminated the problems of gas flow restrictions. Sinter plant trials were conducted over a period of two weeks with the addition of pellet calcine to the sinter feed. Results showed a marked improvement in sinter plant performance, and as a result of better bed permeability, increased sinter production was achieved, with- out significant deterioration in sinter quality.

Jan 1, 1974

Comminution Kinetics equations are developed to take into account difference of grindability of mineral components. The equations describing both batch and closed circuit grinding or crushing processes are given. These equations are applied to industrial data to derive comminution kinetic and classification characteristics of the component minerals in a multi-mineral ore. Control strategy based on these concepts is presented.

Jan 1, 1985

The high cost of sampling systems is largely due to the fact that indiv- idual mechanical type sampling units must be installed at the discharge end of ore/pulp pipelines, that is, at points where the pipeline discharges into pump sumps or the like. A considerable economic advantage may be obtained in the use of a samp- ling device that can be installed at any point in the path of the trans- porting pipe line. Initial tests on a vertical line with an injection sampler using iron ore concentrates reveal the validity of this type sample versus that taken with a mechanical sampler. A descrip- tion of the injection sampler shows its simplicity of installation, requir- ing minimum downtime on existing lines.

Jan 1, 1976

By Hagan T. O

The problem of rockbursts presents a serious threat to many deep, hard-rock mines. For several decades, the owners and managers of affected mines have been concious of the urgent need to control rockbursts but, to a large extent, their efforts have been hampered by a lack of fundamental knowledge. This paper will attempt to outline the extent and depth of present understanding of the phenomenon and to show how better control may be achieved in the future. It is suggested that it is helpful to distinguish two aspects of the problem: that pertaining to the mechanism of the seismic event and that associated with the mechanism of damage. Understanding damage mechanism will enable development of better support techniques while proper understanding of the source mechanism could lead to better mine planning and improved stoping layouts. In this regard, the practice of partial extraction with systematic strike stabilising pillars is discussed in some detail.

Jan 1, 1986

By Van Barnefield J G

This paper is based on an evaluation project engaged upon jointly by Mount Isa Mines Limited nnd" IBM Austra]ia Limited. Mount Isa Mines Limited produces most of its copper from large underground open stopes within massive orebodies. Variations in the position and shapes of these stopes can result in improved metal recovery. An interactive graphics system has been developed to assist the mine design engineer optimise his design. The system can assist the engineer throughout the orebody visualis- ation, initial design and optimisation phases of his design. At any stage the engineer may call upon the display of gridded mesh data, digitized ore outlines or existing stopes or development (drives, cross-cuts). This information may be viewed in plan or any vertical section or in three dimensions with rotation. Tonnage and grade calculations may be quickly performed for initial stope outlines or for modifications to them during the optimisation phase. The system design is highly modular. An array of functions for the manipulation of coordinate and line information may be linked with the development or stope design functions in whichever way the designer desires.

Jan 1, 1977

By Hughson B

At present sane man-made Improvements and natural features are constraints on unlimited underground mining. 7 hey will continue to remain, as constraints on the future high production mining systems as wall. Unless these constraints are overacTe by research, where possible, future high production systems may became unacceptable. 7 he areas of future research include improved subsidence prediction techniques applicable to future mining systems, subsurface subsidence behaviour, mining systems capable of producing no surface subsidence and subsidence damage assessment.

Jan 1, 1988

By Tagawa H

In Japan, geological condition do not only vary in a wide range of strata but are also extremely complex with the existence of faults and aquifers. With respect to rocks, in particular, it is very rare that homogeneous rocks are distributed uniformly. In general, geological conditions are distributed in a wide variety, ranging from earth, sand, soft and medium rocks to hard rocks. Under these geological conditions, when planning of the tunnel construction is to be made out, either blasting method or tunnel boring machines must be selected taking into consideration the geological structures along with the designed tunnel route,' possibility of encountering aquifers, hardness of rocks anticipated and also, the adjacent environ- mental conditions. In the process of select- ing an excavation method,, it is important to make a comparative investigation between the above two methods considering the advantages and disadvantages with regard to the respective operating efficiency, economical efficiency and the conditions and scope of application as well. Furthermore, in addition to these considerations, the recent environmental restriction, which does not allow the blasting in the surroundings of residential areas, must also be taken into account. Because of this, in some cases there is no alternative but to use a static excavation method or a tunneling machine even when these are less efficient than blasting.

Jan 1, 1987

By N Johansson, D Johansson, A Beyglou, H Schunnesson

As demand for optimisation of mining processes increases, more attention is drawn to blast performance and fragmentation improvement. Fractures and discontinuities are among the most influential factors in blast results, therefore one of the initial steps towards blast optimisation is to gather information about the rock mass and integrate it in blast design. This paper presents a method for assessment of rock mass discontinuities and integrating it in production blasts in the Aitik open pit copper mine in Sweden.3D photogrammetric techniques were utilised to map discontinuities and distinguish domains of similar geologic structures in the pit. As a pilot study for a future campaign, four different initiation directions were tested through six pilot blasts in one of the domains. The results were compared in terms of swell and loading efficiency of rope shovels to identify the correlation between blast performance and initiation direction compared to major discontinuity families.It was established that in the trial domain, blasts initiated towards north or north-west yielded larger swell and better performance of loading. Comparing these blasts with discontinuity families show that there is a correlation between blast performance and initiation direction according to the dip and strike of these discontinuities. Such knowledge can be used for future blasts in the same domain to increase long-term operational efficiency through slight modifications in drill pattern and initiation design.CITATION:Beyglou, A, Schunnesson, H, Johansson, D and Johansson, N, 2015. Adjusting initiation direction to domains of rock mass discontinuities in Aitik open pit mine, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 385–392 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

The mineralogy of regolith material for which whole rock geochemistry has already been done can be used to better understand/rank the significance of geochemical anomalies. Case studies show that the secondary minerals of the regolith environment have quite different capacities to incorporate pathfinder and target elements, eg hematite appears to be a better host to Pb than goethite and Pb rich alunite-jarosite minerals are a better Ag host than mimetite. Thus correlations between elements in regolith material may be strongly affected by mineralogy. Understanding of the significance of a geochemical anomaly is frequently enhanced by knowledge of the weathering susceptibility of different minerals. For example, when a mineralogical sequence which does not correspond to the expected order is found (eg feldspar overlying weathered material without feldspars) it is possible that transported material is present in the profile. Such mineralogical information is particularly relevant as exploration continues into areas of thick regolith.

Jan 1, 1997

The estimate of an ore reserve is a vital statement made about a mineral occurrence by an evaluator. It is important that such a statement communicate reality to all groups involved in a mining project, be they technical, financial, company directors, Stock Exchanges or the public. Ore reserve statements should state both resources and recoverable ore reserves. Resources may be important in very long term considerations, (because mining, metallurgical technology and economics change with time) but recoverable reserves are todays reality. The important factors contributing to recoverable reserves (in a general sense) are geology, mining method (and its impact on dilution and ore loss), metallurgical recovery, costs and commodity prices. These all need to be reflected in the ore reserve statement. In this paper recoverable ore reserve concepts across a wide range of orebodies are considered and discussed with respect to geology, mining method and ore reserve calculation procedures.

Jan 1, 1987

This paper briefly discusses the negotia- tion of the more important provisions in agree- ments for exploration and mining rights with Pacific countries. LAND RIGHTS Land rights are complicated and sometimes controversial in many of the Pacific countries. In some countries, a company will have to deal with land owners directly; in others, the government will act as intermediary. Inevit- ably, a company will have to deal with both. Mining companies need to be sensitive to the culture and particular interests of the land owners and of their history in defending their rights. The issues are too complicated to be dealt with here. Some mining companies have spent, and will continue to spend, considerable time trying to understand them. It will " require patience, perseverance, sensitivity and unflagging optimism. The better advised companies will ensure that their local repre- sentatives get to know the land owners, under- stand their concerns, and will pursue a policy of keeping them informed on a regular basis of all of the company's activities and proposed activities. Good community relations are the keystone for good mining operations in the Pacific. Most countries will require the submission of an environmental impact statement so that they will know in advance what effects a pro- posted mining operation are expected to have on the environment and how it is intended to deal with them. They will also want to approve the company's environmental reclamation and rehabilitation plan. Let's face facts right away - mining, by its very nature, is not going to improve the environment. There will be waste discharges, emissions and deposits. They will affect the land, air and water and hence human, marine and animal life and vegetation. There will be sounds and odours and the esthetics of mining operations, though perhaps pleasing to geolo- gists and mining engineers, will not please Others.

Jan 1, 1987

By S Roberston, G Batt, R Shanahan, B Shah, A Trench, H Bromfield

The geographic imperative of ore systems leaves mining, more so than virtually any other aspect of modern industry, heavily dependent on obtaining and maintaining social licence to operate. A prospective miner cannot arbitrarily walk away from a deposit in search of more favourable community perceptions – concentrations of mineral endowment represent highly specific and fixed elements of the landscape, and their development and extraction thus requires the acceptance and trust of a specific network of landholders and stakeholders, sometimes with diverse and even competing interests in the development and use of the local environment. Weakness or absence of such social licence can bring added costs and complexity to developing and operating a mine – and in extreme cases even result in project failure. Because it must be maintained throughout the life of a project, such social risk becomes a substantial part of overall project risk profile, particularly during routine operations once initial technical and development risks have been largely resolved.CITATION: Bromfield, H, Roberston, S, Shah, B, Shanahan, R, Trench, A and Batt, G, 2018. On equitable distribution of mining wealth and the social licence to operate imperative – an African case study, in Proceedings Complex Orebodies Conference 2018, pp 6–7 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018