Search Documents

By Floyd JM

Conventional smelting reactor systems were designed to recover only one main element from their feedstocks. They did not possess sufficient flexibility to allow optimisation of co-production of multiple values from a complex feed.New reactors such as Sirosmelt and Top Blown Rotary Converters are providing new possibilities for making separation between components and this is of great significance for the complex feeds which are becoming prevalent in the metal extraction industry.Process routes using chemical procedures which take advantage of the flexibility of these reactors will be discussed in relation to a number of possible feedstocks.

Jan 1, 1985

By Simes C. D

Results of experiments for dissolution of zinc by aeration of sphalerite in glass, copper, galvanised iron and stainless steel vessels of identical dimensions are reported. It was found that in a glass container dissolution of zinc reaches a maximum after 30 min aeration and then decreases whereas in the copper container dissolution remains nearly unchanged up to 30 min aeration and then increases. In the cases of galvanised iron and stainless steel containers zinc dissolution increased steadily with time up to 60 min aeration. It is suggested that the different rates of dissolution in glass and copper containers may be due to electro-chemical actions.

Jan 1, 1984

By Hosking JW, Muir DM, Ruane M, Smith I. Hinchliffe WD

Maintaining carbon activity is critical to the satisfactory recovery of gold in the Carbon-in-Pulp (C.I.P.) process. Reduced activity can lead to gold losses in tails and lower tonnage throughput.Carbons from a number of W.A. C.I.P. circuits have been examined for the extent of fouling by inorganics such as calcium, magnesium, copper, nickel and silicon. Many of these carbons have exceedingly low activity leadingto low gold loading and excessive contact times. The relative importance of these fouling agents and cyanide levels on carbon activity is discussed. Mathematical modelling shows that relatively small improvements in kineticactivity lead to much lower tank volume require-ments and carbon residence times.

Jan 1, 1984

North Stradbroke Island is a large sand mass offshore from south east Queensland. Dredging for mineral sands commenced there in 1956 and the rehabilitation discussed in this paper was commenced in 1967. The frontal dunes have a long history of instability, with little vegetation prior to mining. Re-establishment of the naturally stable contours is essential, and their rehab- ilitation is described. Vegetated high dunes present different problems requiring attention to regeneration of the native species. Methods developed over the past eight years are proving successful.,

Jan 1, 1976

Pbo activities have been measured in conventional blast furnace and direct smelting type slags at 1200¦C. Much higher activity coefficients than previously measured have been obtained and attributed to interactions between iron and lead oxides. The behaviour of PbO in the two types of slag reflects their relative silica contents. Simple equations derived from mathematical modelling work are presented for the prediction of Pbo activities in complex industrial slags.

Jan 1, 1984

Mary Kathleen Uranium Ltd. recommenced operations in early 1976 following a twelve year period of care and maintenance. Several sections of the plant were modified or completely changed for the second operation. The most important change was the replacement of ion exchange with solvent extraction as the means of purifying and upgrading uranium rich Isolutions Most of the problems experienced in the solvent extraction system originate from the leach liquor which has a strong tendency to form stable emulsions. This has been countered by some careful control of leaching conditions and by closer observation of operations in the solvent extraction area. Most problems have now been resolved and plant recoveries are quite Satisfactory.

Jan 1, 1978

The development of paraprofessional courses in metallurgy and related disciplines, by the Department of Technical and Further Education in New South Wales, is outlined in this paper. The changing nature of metall- urgical educational requirements is summarised, and various attendance patterns discussed. The potential advantages of the sandwich system of College attendance, to the more distant sectors of the mineral processing and metallurgical industry is outlined. Some of the likely future trends in technician education are presented. These include the need to respond to the changing expectations of technician employers, as shown by industrial surveys, the role of experiential learning, the need to integrate courses so that students can build on prev- iously completed courses, the possibility that future technicians will require a multi- disciplinary background and the provision of easier access to technical college facilities by potential students and industries.

Jan 1, 1978

By Budd B

this paper outlines the operating advantages gained through applying a mine processor (MISA), to various underground and surface operations. On the surface, MISA monitors and/or controls ventilation fans, crushers, fill plant and stockpiles. Underground, MISA monitors and/or controls dewatering pumps, fill reticulation and high voltage electrical distribution on most levels.

Jan 1, 1988

By Gelding P. W, van Herk H

The Cattlegrid copper orebody is a concealed thin, tabular sheet localised near an unconformity between two sub- horizontal Precambrian sandstone units. It extends over an area of 1,000 m by 500 m within a wider area of mineral- isation. The ore consists of complex sulphides and is neither massive nor disseminated. It consists mainly of irregular fillings in pore space developed between clasts in sandstone breccias, in fault zones and joints and along stratification planes. Its habit is unique amongst Australian base metal ore bodies. During the pre-development period ore was outlined by percussion holes but in studies leading to investment decisions ore reserves were manually calculated from intercepts and assay results of cores from diamond drill holes. The methods used for estimating reserves in the pre-production and production periods are described and evaluated by comparing mine production during the first five ore production years with the forecasts made.

Jan 1, 1979

Operations at two open cut mines have so far commenced on two out of the five potentially mineable seams in the Fair Hill - German Creek Coal Measures. Due to seam splitting, up to seven mining units are present in the Dysart Seam interval at Peak Downs giving a total of 12 mining units in the section. The coal is low to medium volatile type and produces strong coke. Rank increases and fluidity decreases in the southern part of the area.

Jan 1, 1974

By S Strohmayr, R Harvey, A See

Ernest Henry Mining Pty Ltd started production in August 1997. The Ernest Henry orebody consists of two distinct parts, a complex supergene ore zone overlying a primary ore zone. The economic copper minerals in the supergene ore were chalcocite, bornite, secondary chalcopyrite and native copper while the primary zone has only chalcopyrite. The variability of the supergene zone made concentrator operation difficult and predicting metallurgical performance using mineralogy essential to establish the capabilities of the concentrator. A paper presented at the 1998 Mine to Mill Conference entitled Mineralogy Controlling Metallurgy at Ernest Henry Mining (Barnes, Strohmayr, Brindley and Munro, 1998) presented the testwork and initial plant surveys that showed that the mineralogy of the ore controls the metallurgy of the concentrator. This paper presents the data obtained from the subsequent years of operation treating both the supergene and primary ore types. A review of the actual supergene mineral distribution in feed and subsequent recoveries compared to those predicted as part of the flowsheet design is also presented.

Jan 1, 2003

By Smith I. K

A Data Acquisition System with a capacity to monitor 2000 analog instruments has been installed at the mines operated by the Zinc Lorporation, Limited and New broken hill Consolidated Limited (ZC/LVbHC), New South Wales, Australia. Since commissioning in March, 1982, the system has proved its value in providing up-to-date information to both Rock Mechanics and Mining personnel. The paper describes the function of the major software and hardware components of the system, and identifies the advantages that an on-line monitoring system provides in the day-to-day operation of a large underground mine.

Jan 1, 1983

By C Deacon

It is common practice to include microspheres or similar density reducing agents in inherently insensitive water-based commercial explosives to achieve detonative sensitivity in the absence of chemical sensitisation. It has recently become possible to similarly include microspheres in LDAN (low density ammonium nitrate). Further to previous studies and publications to determine the benefits resulting from the use of microsphere enhanced LDAN technology in blasting, additional advantages are described in this document. These include range tests at independent testing facilities (Universal Tech Corporation û USA) which reflect results observed in the field, and support theoretical assumptions made when the products were introduced. Additionally, on-site studies in opencast pits using Heavy-ANFO blends incorporating modified LDAN, show that monetary savings can be realised through significant advantages gained in plant throughput and explosives use.

Jan 1, 1999

By Tomlinson R. C

The paper will briefly describe planning in the National Coal Board (NCB) and the contribution that operational research makes to it. It will then give details of some of the models in use and will finally consider critically the problems of looking ahead to the next century.

Jan 1, 1977

By Pease JD, Munro PD

The heavy medium cyclone plant for the preconcentration of silver-lead-zinc ore prior to grinding and flotation was commissioned in August 1982. This paper details the measures taken to get the plant up to design performance which involved modifications to the medium densifying and slimes clarifying sections. Operating experiences to date are described with emphasis on the low medium consumption recorded and severe wear on process equipment.

Jan 1, 1984

By M D. Boscardin, P A. Roy

The North Shore Connector Project for the Port Authority of Allegheny County involves TBM tunnelling twin light rail tunnels through cohesive soils and rock under the Allegheny River and a narrow city street. Along the tunnel alignment are a listed historic building on shallow foundations as well as modern buildings on deep foundations; one major office block was actually constructed directly over the alignment during the latter phases of design process. This paper provides an overview of the general site conditions, tunnel design and the technical basis for excavation support and tunnelling decisions. Deformation limits, ground improvement, monitoring and mitigation plans are also discussed. Project construction has now commenced and a brief summary of progress to date is included in this paper; this will be updated for the presentation to be made in Melbourne.

Jan 1, 2008

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

The paper examines the possibility of applying the monolithic packing technique developed in the UK to the division of wide development drivages in Australia, so enabling double entries for longwall retreat panels to be created from shortwall units. The monolithic pack of the UK therefore becomes a monolithic partition in this proposed Australian application. A method developed for the analysis of the load development in packs installed behind longwall advancing faces is adapted and used to predict the support performance of the monolithic partition. Conclusions are made regarding partition construction and possible rates of advance.

Jan 1, 1986

By R W. Wilson, F H. von Glehn

With ever-increasing energy costs and the modern focus on system efficiencies, the practice of æventilation-on-demandÆ is gaining momentum. Several examples, ranging from paper studies to practical examples have been recorded and another recent case study is presented here to encourage the practice. In comparison, æcooling-on-demandÆ has received far less attention. This paper explores the possible merits of this practice by investigating the theoretical response of cool intake airways and the thermal interaction between the air and the rock, in order to gain a better understanding of the system behaviour and to quantify the possible savings. A case study is presented that demonstrates the improvements that can be achieved. Recent developments that allow live interaction between ventilation network models and on-line monitoring systems, have the potential for intelligent active control and alarming of ventilation and cooling networks. This will facilitate and maximise the benefits to be derived from ventilation and cooling-on-demand.

Jan 1, 2005

By Madgwick J. C

Bacterial leaching of museum grade chalcopyrite and chalcopyrite concentrates at low sorptive relative humidities (55-91 per cent rH) was demonstrated. Optimum release rates were 13 and 27 mg/gram/100 days copper (Cu++) at 91 per cent and 80 per cent rH and 12 and 33 mg/gram/100 days iron (Fe++) at 80 per cent and 73 per cent rH for concentrate and "pure" chalcopyrite respectively. The optimum copper release rates occurred between 73 per cent - 86 per cent rH and 30-40 mM acid concentrations. Bacterial copper leaching rates were some twenty times slower for emersed copper concentrates, at low relative humidity, compared with submerged cultures. Bacterial copper solubilization was almost quantitatively inhibited above 150 mM acid levels (< pHO.8).

Jan 1, 1984