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Selective Recovery of Platinum from Cobalt-Rich Crust

Sep 13, 2010

By C A. Locke

Geophysical signatures of the Taranaki and Tongariro volcanoes reflect similarities in their age, composition and hydrothermal histories, but also reflect differences in host rock settings and edifice evolution. The Taranaki volcanoes have strong positive gravity anomalies showing that their edifices largely consist of dense andesite which reflects substantial lava production or dyke injection during construction and that large sub-edifice dyke/stock complexes occur. In contrast, the Tongariro volcanoes have strong negative gravity anomalies indicating low density edifices of volcaniclastic material; no sub-edifice intrusions can be identified, probably because of the lack of density contrast with host basement rocks. Strong positive magnetic anomalies over the younger cones can mainly be attributed to near-surface andesite lavas or dykes whereas subdued magnetic effects are associated with hydrothermally altered zones within both edifices and sub-edifice intrusions.  

Jan 1, 1995

The seams of black coal occurring in Victoria are so disturbed by faulting, wash-outs, thinning, etc., that it is necessary, for the prevention of costly errors in development, that close boring be undertaken so that the correct positions of the shafts, tunnels, main and auxiliary roadways can be set out in order that the area can be economically worked. The State Coal Mine has two boring plants continuously at work, which have given good service for the last twenty-five years.The information supplied herein is merely our experience in boring at the State Coal Mine over an extended period. The type of plant in use is that known as the Victoria Drilling Plant, equipped with an 11 h.p. portable oil engine, using power kerosene as fuel. It was purchased in 1914, complete with mechanism for cable drilling, capable of boring to a depth of 1500 ft. with a guarantee of 1000 ft., with Calyx cutters, boring rods and all necessary equipment for the sum of £1473. The chief mechanical features of the plant are as follows:-The derrick is in the shape of a tripod (see Fig. 1), two of the legs being of steel channel built together to form a frame which, when lowered on to two sets of road wheels, forms a carriage for the transport of a portion of the boring equipment. The third leg is made of oregon in the form of a double bow, with bolts and distance pieces between the wooden sides. The top of this is hinged on to the steel frame, and the bottom is fitted into a cast iron block, having two small wheels to facilitate erection. A rope attached to the cast iron block and to the winch easily...

Jan 1, 1936

The clay slime generatea in many sand washing operations is usually very difficult to de-water. Treatment of these slimes is often limited by economic considerations and the properties of the solids to a gravity-driven process. The moisture characteristics of kaolinitic slimes from two different sand washing operations were measured.From these curves, equilibrium moisture contents for sedimentation and for drainage were calculated using the methods of soil physics. The validity of these calculations were confirmed by column experiments.The results show that the increased de-watering to be gained by drainage, as compared with sedimentation, is significant. Furthermore, observed rates of outflow indicate that water can be removed considerably morerapidly when drainage is possible.The practical application of these results to the dewatering of clay slimes is discussed.

Jan 1, 1978

By Gibbs R

The objective of this paper is to provide a broad qualitative perspective of the needs and costs of infrastructure associated with typical mining projects. Infrastructure may be defined as anything necessary for the development and operation of a project, which is peripheral to the basic extraction, handling and processing of material. As depicted in Figure 1, infrastructure acts as the link between the technological heart of a project and the outside world.

Jan 1, 1990

By R Bertuzzi

This paper presents a three-dimensional analysis of a trapezoidal-shaped segmental tunnel lining for a recent tunnelling project in Sydney. Two- dimensional analyses, hand calculations and equipment selection defined the lining geometry and loads. The analysis, which was undertaken using 3DEC (Itasca), included a complete ring of six segments bolted together to assess the impact of imperfectly built rings. Asymmetry was induced in the analysis by unfavourable positioning of segments within construction tolerances. Model output includes displacement and stress within the entire ring and normal, shear and bending moments at the joints. For the case analysed, the results suggest a 10 mm construction tolerance increases normal and shear stresses along the radial joints by approximately 25 per cent and 15 per cent, respectively and up to a doubling of the induced moments.

Jan 1, 2008

By R Shaw, M Hidding

The design of primary sample cutters for high-capacity conveyors is critical to achieving a correct sample, both in collecting the sample and ensuring smooth sample discharge flow. Modelling usually occurs at the design stage and requires extensive experience to achieve the correct result. However, it is difficult to confirm the effectiveness of the cutter design until after installation. Even with high-speed video, confirmation of complete sample capture is difficult, especially if the material characteristics change over time. Recent investigation using discrete element method (DEM) simulation to model the flow of the ore into the cutter and observe how it interacts with the cutter has revealed some interesting design requirements not observed in the past. By including DEM modelling, the correct design and optimisation of the cutter can be more accurately determined prior to commissioning.CITATION:Hidding, M and Shaw, R, 2017. Modelling ore flow in the design of high-capacity sample cutters, in Proceedings Eighth World Conference on Sampling and Blending , pp 145–150 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

The geological features of the destructive plate margins of the southwest Pacific favour the formation of porphyry type deposits. The major controlling factor favouring the formation of gold-rich deposits of this type is a dense crust. This results in shallow intrusion of large magma bodies beneath andesite stratovolcanoes. Where the intrusives have near vertical sides, the comparatively low temperature of transfer of volatiles from the solidifying melt favours the partitioning of gold into bubbles of volatiles. They reduce the viscosity and density of the melt, resulting in the upward movement of a mineralised melt. With the drop of pressure with upward movement the bubbles separate into a two phase mixture, triggering freezing of the mineralised melt and the formation of a gold mineralised stockwork.

Jan 1, 1995

THE machine from which the following results were obtained makes one of a row of seven at work in the Junction North, Concentration Mill at Broken Hill, New South Wales. It consists essentially of a belt for dressing purposes, which travels round two 12-in drums situated at either end of a wooden frame. This frame is supported on wooden legs, and the whole is affixed to two iron castings, one on either side of the frame. A to-and-fro motion is obtained from an eccentric shaft, which, together with the stationary end of the supporting legs, is carried by the iron castings. A belt drive to the forward drum provides a constant rate of travel to the dressing belt.The top half of the dressing belt is supported on 3-in rollers spaced about 12-in centres along the frame of the vanner. A fairly thick dressing belt is used, and no trouble whatever is experienced from the formation of gutters between the rollers.These belts are 28 ft 4 in long, 4 ft wide, 3-16 in thick, and are made of two-ply 32-oz duck, with a coating of rubber on either side. The surface available for dressing is about 10 ft 6 in x 3 ft 8 in- ie, about 38'5 square feet. The machine is driven atthe rate of 245 i-in strokes per minute, while the dressing belt travels at 15 feet per minute...

Jan 1, 1909

This paper is a collection of thoughts and frameworks. It addresses a simple question: æIf we are to believe the large number of people and institutions indicating that humans are destroying the Earth and that the end is nigh, why do we bother trying to be sustainable?Æ The paper lays out evidence for the existence of multiple hazards to global society. The existence of a hazard alone is insufficient to make an assessment of risk. Risk estimates are required to support decision-making. An approach to assessing risk is provided and some limited data are presented. A new ædefinitionÆ or statement of what sustainability (in a broad sense) might have become is then given. A decision framework for guiding decision- making about the risks is developed. This framework includes a definition of leadership with inherent implications for what determines whether a leadership position by title is actually leading. The paper concludes by offering a view of minerals industry sustainability and considerations around maturity in the current economic situation. It is hoped that by placing this collection of frameworks around sustainability, a supporting structure emerges that will facilitate action. It is proposed that action taken in this way will be more effective than reaction to regulation or even social license to operate imperatives because it is driven by a more holistic view of the challenges and the potential roles of individuals û all of whom are potential leaders at some scale of action.

Jan 1, 2009

A process was developed, on a laboratory scale, for the removal of iron oxides from Weipa pisolitic bauxite. The technique involves the chemical reduction ofthe iron oxides by carbon, followed by selective removal of the iron species by acid leaching or chlorination.To remove more than 90 per cent of the iron it is necessary to reduce the iron oxides substantially to iron metal by heating the bauxite, pre-calcined at 650-800°C, with reactive carbon at 1040-1100°C. Reduction proceeds via the intermediate formation of hercynite (FeO.Al2O3) and difficulties have been encountered in reducing hercynite formed under less favourable reduction conditions.Following reduction, efficient selective removal of iron species is readily effected by acid leaching using dilute hydrochloric acid at 100°C, or chlorination at 500-750°C using Cl2, Cl2/N2, or Cl2/N2/CO mixtures.After removal of unreacted carbon, the final products contain 0·5-1.0 per cent Fe203 and 87-92 per cent Al203.

Jan 1, 1971

This paper discusses support requirements for the proposed monorail system to be used in decline development. The monorail drilling and loading systems are systems that move on the rail (monorail) installed in the roof of the decline and supported by roof bolts, suspension chains and steel supports. However, due to the weight of the components of the two systems, it is imperative that the force in each roof bolt, suspension chain and steel support capable of suspending the weight of the heaviest component is determined. Numerical models that relate the weight of the monorail drilling and loading components to the required strength in the support system have been developed. Using these developed models, numerical values of the forces in each roof bolt, suspension chain and steel support, required to suspend the weight of the heaviest component of the monorail drilling and loading systems are determined.

Dec 6, 2010

A short account is given of the theory and practice of determining the true U3O8 content of ore samples by the determination of the beta and gamma activities separately, using the method of Eichholz and his associates.It is shown that, despite the variation of sample activity without change in U3O8 content, the true U3O8 value can still be found.Thorium can be determined simultaneously if this element is also present.

Jan 1, 1957

By Z Li, A Fleming, S Webster, L Snyman

Northparkes Mines is developing the E26 Lift 1 North block cave mine, which is adjoined to the existing E26 cave. This paper presents the challenges and methods used to design the ground support system during the feasibility study. Calibrated numerical simulations were conducted to forecast the levels of rock mass damage and to assist the ground support design. Generally, low to moderate rock mass damage is forecast on the extraction and undercut levels. However, poor ground conditions are expected in sheared and preconditioned zones adjacent the existing E26 cave. This will result in difficult ground conditions during development, undercutting and drawbell establishment. Empirical assessments were conducted to make sure the ground support system is able to handle both the static and dynamic load demand, and to accommodate the deformation values. A safety factor of 1.5 was used for the designs to cover the unknown rock mass conditions and potential for larger seismic events. Learnings from the E26 Lift 1 and SLC, also mining against the E26 cave, are incorporated into the design. Fibrecrete, mesh and resin bolts / mechanical anchors are the primary ground support system used, and cable bolts for intersections with a span of more than 6 m. Following undercutting and during the operating life of the mine, secondary ground support and rehabilitation will be required.

Mar 15, 2021

Myths and misconceptions regarding cyanide in the mining industry are common. This is not surprising, given the other uses to which cyanide is, and has been put. Unfortunately, the economic benefits, largely due to the introduction of cyanide in towns such as Waihi are often unrecognized. In the current "green" environment, the New Zealand mining industry faces constant scrutiny and challenge. The use of cyanide in hard rock mining is one area which can stir the emotions of the public.   Cyanide can be transported, stored, used and disposed of in a safe manner. The modem mining industry has an excellent record regarding the safety and environmental issues relating to cyanide. Many of the fears relating to cyanide in the mining industry have proven to be unfounded. It is important that this reputation is maintained. This is possible given proactive and ongoing management of cyanide issues.

Jan 1, 1997

Upgrading and Removing Phosphorus from Low-Grade and High Phosphorus Containing Iron Ores

Sep 13, 2010

By R G. Richards

The Australian glass sand industry produces some 2.8 million tonnes per annum of silica sand, of which about 2.0 million tonnes are exported and the rest is for the domestic market. Approximate production rates for each Australian state are listed. The variety of processing methods used in the currently exploited deposits reflects the size, location, and characteristics of the various deposits and the requirement of the end market/s. The industry uses to a large extent equipment developed for the separation of mineral sands, particularly as it applies to low grade heavy mineral deposits, where low cost, high capacity and metallurgically efficient equipment has proved eminently suitable for the production of the low value glass sands. The requirements of the domestic market, as well as those of the present and potential export markets are discussed covering quality requirements, distribution channels and other factors critical to success.

Jan 1, 1990

The modern Golden Cross mine entered the production phase in January 1992. The project is designed to produce over 100 000 oz/yr of gold and over 300 000 oz/yr of silver during a mine life of eight years. An open pit and an underground mine are operated producing around 850 000 t/yr of ore, to feed a conventional carbon-in-leach processing plant. Golden Cross is owned in joint venture by Coeur Gold New Zealand Limited (80%) and Viking Mining Company Limited (20 %).   Since the start of production several major aspects of the design have altered. The underground mine began as a mechanised cut and fill operation. The cut and fill stoping progresses in 3.3 m flatback lifts with maximum stoping width of 6 m. Where the ore zone is wider than 6 m a post pillar cut and fill method is used. In 1993 a new bench mining plan was introduced between the 270 and 260 levels. Flatbacking continued in the footwall drives in anticipation of variability of the ore width and orientation. The development of levels below the main service 200 level has indicated a possibility of bulk mining the ore block rather than flatbacks. This could lower mining costs but also introduce higher dilution rates. Development is in the advanced stages for trialing this method.

Jan 1, 1994

AustraliaÆs strong position as an aluminium producer and potential magnesium producer combined with rapid market growth in the automotive industry, proximity to Asia and other natural advantages points to considerable opportunity for downstream processing and manufacture with light metals in this country. Development of a vertically integrated light metals industry in Australia needs to be pursued with vigour, as does the continued development of global strategic alliances through the value adding chain.

Jan 1, 2000

By M A. Mongillo

Most geophysical and geochemical data collected during regional exploration programmes are in vector form (location, value), and have traditionally been presented and interpreted in a profile or contour map format. However, the human vision system can interpret data presented in image format much more easily and new information is often revealed by the judicious application of powerful interactive computer image enhancement techniques. This paper describes a practical demonstration of the application of such tools to gravity and resistivity datasets from the Central Volcanic Region of theNorth Island.   Filtering, contrast enhancement, relief shading, pseudo-colouring and then overlaying of the gridded datasets in image format has helped identify inter-relationships such as the association between many low resistivity anomalies (epithermal deposits or geothermal resources) and the edges of large gravity anomalies (calderas or grabens). Similar revelations should result from the application of these tools to the integration of other mapped datasets from geophysical, geochemical and geological disciplines.

Jan 1, 1992