Search Documents

By P Hucker, E Hall

Harmony Gold operates the Mount Marion underground gold mine near Kalgoorlie, Western Australia. The mine consists of two ore zones, East and West, and mining of these zones is currently conducted using the sublevel caving method. When mining commenced in the Western zone, the span was insufficient to induce caving of the country rock above. Dyno Nobel, together with Harmony and 360 Drilling, developed an innovative drill and blast solution in order to promote cave propagation and improve the safety of personnel at the operation. The solution involved a series of shallow angle drill holes up to 90 m into the hanging wall of the West zone. These were charged with Titan« 7000 underground bulk emulsion and the HotShotÖ electronic initiation system. The blast used over seven tonnes of emulsion and 46 detonators and achieved the desired result without damaging nearby mine infrastructure.

Jan 1, 2007

During 1979 the writer had the privilege of interviewing about 50 people with varying degrees of involvement in the industrial arena and all of them in one way and another, had a part to play in the huge and intricate saga of Australian employee relations. They fell into the following' categories Industrial Relations Officers/Managers Academics Politicians Union Officials Representatives of Employer Associations Senior Industrialists Commission Members (State and Federal) Sundry (Journalists, Government Officials). This paper seeks to give an account of their views on various aspects of industrial relations. The interviews conducted were all on a personal and confidential basis so it can be expected that sources will not be identified. Suffice it to say that this account represents, albeit in "potted" form, the opinions of some of the most experienced individuals in the country. It will be seen that in most of the vital areas there is a remarkable lack of consensus. It should be noted that this lack of consensus existed within each of the groups mentioned.

Jan 1, 1980

By L Crew, S Jackson

A trial of an Adept Online Ore Sizer (OOS) was undertaken at the WMC Leinster Nickel Operation (LNO) in the first half of 2000. During this time the On Line Ore Sizer has been shown to be a robust and accurate instrument for measuring mill feed ore size. Data collected during the trial indicates significant variation in the F80 of the SAG mill feed. The effects of feed size on milling parameters such as mill weight, mill power draw and mill efficiency appears to be dependent on the ore blend treated. With some ore blends a weak positive correlation was found between ore size and mill weight and milling efficiency but with others no correlation is evident. It is believed that the OOS will become a vital piece of equipment in the future as LNO continues to optimises its milling circuit.

Jan 1, 2000

By Jimbo I, Ogawa O

A series of experiments was carried out to investigate the solubilities of copper, arsenic, antimony and bismuth in silica-saturated iron silicate slags under controlled oxygen partial pressures at 1200 and 1250¦C. Molten copper containing each of the above elements was kept in contact with a slag in a silica crucible for 24 or 48 hours to attain equilibrium. No me- chanical entrapment of metal into the slag was observed. The appearance of the magnetite phase in the slag was avoided by holding oxygen potentials at substantially lower values than that evaluated from available data on iron silicate slags. Solubilities of copper, arsenic, antimony and bismuth in slags were plotted against oxy- gen potentials and both oxidic and atomic types of dissolution were found, except in the case of arsenic, from the dependencies of the solubili- ties on the oxygen potential and from positive intercepts of regression lines when extra- polated to zero oxygen potential. The dissolu- tion of arsenic seemed mostly oxidic. Distri- bution coefficients of arseò,ic, antimony and bismuth between copper and slag are also Discussed.

Jan 1, 1980

In preparation of this Paper, the emphasis has been laid on the commercial rather than on the technical and scientific aspects of coal evaluation. It is intended to describe and comment on the principal factors which currently determine the selection and procurement of coking coal for the steel industry, and is not based on the results of any original research by the author. Evaluation of different coals for strictly thermal uses, for gas production or other chemical applications has not been attempted, and comparisons of coal with other fuels have been excluded: the paper is concerned only with coals for the production of blast furnace coke. The discussion is strongly related to, and illustrated by, British, and to some extent, other Western European practice, but it is hoped that the general conclusions may have a wider application.

Jan 1, 1975

By Jones BH

Discovery of the Vera-Nancy deposit in late-1995 followed 12 years of active exploration in and around the Pajingo Epithermal System, an andesite hosted veinfield covering an area of 150 square kilometres at the northern end of the Devono-Carboniferous Drummond Basin in North Queensland. Early exploration targeted open-pittable resources in the numerous auriferous veins and it was not until 1994 that exploration focus shifted to drilling to depths below about 100 metres from surface, which resulted in the Vera-Nancy discovery. That deeper drilling process is still at a very early stage of coverage of the epithermal system as a whole and substantial potential exists for additional discoveries.Drill-out of Vera-Nancy has to-date established a gold resource in excess of 1.4 million ounces. Mine development is proceeding via a twin decline system with first stoped production scheduled for August 1997.

Jan 1, 1997

By Coskun B

The classification of selective mining units (SMU's) and the assignment of grades to those classified SMU's are very important in open pit mining, especially for precious metal mining. During ore control planning, the classification of mineral

Jan 1, 1998

By Estoque J, Lodrigueza L, Rebillon F

Ore mineralization in Masara consists mainly of gold-silver veins, porphyry copper and pyrometasomatic deposits related to left-lateral movements along the Philip- pine fault system and a later stage of magmatism. These are hosted by pre-Tertiary volcanic flows and volcaniclastics, and comprise a temporal pattern of earlier peripheral copper zone, an intermediate mixed copper-gold area and a later central gold vein system within the Masara sector of the postulated volcanic field. Gold ore emplacement occurred in at least two stages, and shows gradations from a lower mesothermal-epithermal phase passing into a typical epithermal zone, and finally into a truncated, or poorly developed, upper level thermal spring deposit. Orebodies are closely associated with hot springs, solfatara and several magma- related masses, emphasizing their inherent linkage with a geothermal system in the Area.

Jan 1, 1987

This paper documents the relationship between material handling and processing costs compared to blasting cost. The old adage, 'The cheapest crushing is done in the pit', appears accurate in this case study. Comparison of the accumulated cost of powder, selected wear materials and electricity, indicate a strong, inverse correlation with powder factor (lbs powder/long ton of rock). In this case, the increased powder cost is more than offset by electrical savings alone. Measurable, overall costs decline while shovel and crusher productivity rise by about five per cent when powder factor rises by 15 per cent. These trends were previously masked by the effects of weather, ore grade fluctuations and accounting practices.

Jan 1, 1995

By I Kolomaznik

Each technological process can be reduced on the transport networks, and namely on the parametric networks and the non-parametric ones. The parametric networks are created by the piping, electrical cables or channels. The non-parametric network is created by the ways, suspended grooves, trackages and also by the belt conveyors or other conveyors for continuous material transport. If we reduce the technological process on transport networks, then, by the creation of these networks models and their mutual interconnection we obtain the model of the whole technological process. The model can be understood as the universal one, without exaggeration, because it is valid for any technological process. However, for us the mining production process is important what represents the mining and transport of raw materials under the support of the ensuring system. In this contribution one of the first attempt is described, and namely how to connect the parametric network which has been already worked out very properly with the non-parametric network what is presented in this contribution by the transport line of belt conveyors.

Jan 1, 2003

This paper attempts to put into perspective the implications of the legal disclosure requirements for promoters and consultants when making statements concerning ore resources and reserves. The need to take account of non-technical as well as technical factors is highlighted.

Jan 1, 1987

Sustainable development places a heavy burden upon everyone involved in the public policy debate, about how to balance economic growth and environmental protection. We must treat that responsibility very seriously indeed. The mining industry especially cannot dodge the responsibility, even if it wished to.

Jan 1, 1992

A schematic overview of the variables which interact to determine ore reserves precedes consideration, in this context, of some recent views on the concept of a 'production cycle'. Political and governmental action, for whatever motives, is a greater obstacle to future mineral supply than technical problems.

Jan 1, 1979

Reliability is not only important in coal mine planning, production and control. Reliability is also most important, and indeed is fundamental, to successful coal exporting.Coal preparation, blending, distribution, marketing and utilisation are areas of the coal industry in which reliability can be critical to coal exporting. Major elements of reliability which impact on coal exporting include coal quality, supply performance, -coal ownership changes, governmental regulations and policies, market reputations and differences in export markets.

Jan 1, 1991

Predictive chemical models facilitate the selection, design and assessment of aqueous chemical processes. The development of expertise in aqueous themochemistry has not matched the explosion in computer technology for modelling, which has placed pressure on the need for acquisition of skills to critically assess the appropriateness of the models produced. The 'blind faith' culture which appears to be developing must be arrested by appropriate programs at the tertiary level and professional development strategies in the minerals industry.

Jan 1, 1996

The different stages of the metallurgical evaluation of an ore resource and their importance to overall project evaluation are described. Particular emphasis is placed on the liaison that is necessary between the different members of the project team from the preliminary exploration phase through to the completion of the final feasibility study. Metallurgical input at the earliest stage is recommended. The incorporation of metallurgical and marketing data into ore reserve statements and the effect of the metallurgical evaluation on ore reserve classifications are discussed.

Jan 1, 1987

The competitiveness and future growth of the Australian mineral resources industry face a number of challenges. The paper addresses key factors likely to influence the attainment of high performance and continuous improvement including organisational leadership, management/employee relations, technology, safety, health and the environment. Business practices such as benchmarking, Total Quality Management and re-engineering to achieve process and performance improvements are commented on. Future success for the industry will largely hinge on global business skills, a sustained focus on Quality principles and achieving performance through people.

Jan 1, 1997

By Xin J

In China, the State-run mines are currently practising an information card management system, to collect data about mine production and safety condition. Since large volumes of data will be obtained every day, efficiently and effectively processing data and sorting out valuable information will take enormous resources of manpower, if by hand. Therefore, an intelligent database system with easy data inputting was developed to assist information processors in data classifying, filing and retrieving. For analyzing and improving production performances, reliability models and production functions were embodied. The system was implemented on AST-286 in DBASE M. Preliminary applications have proved effective and successful.

Jan 1, 1991

This paper discusses the concepts of core risk associated with mining projects and operations and illustrates the types of core geotechnical risks and consequences that may relate to a range of different mining methods, with recommendations on risk management procedures to ensure that the core risks are under constant and ongoing scrutiny and priority management focus. These core geotechnical risks can and should be identified at the initial mining method selection stage, during a feasibility study. They should form part of the auditing of the project and the decision-making regarding the project viability. They should then be built into the ongoing management structure of the project, right through into ongoing operations, with regular audit and review.

Jan 1, 2003

The paper describes the $US240 million expansion at Hudson Bay Mining and Smelting Co LimitedÆs operations in Canada. The company has been continuously producing copper and zinc from local area mines at its Flin Flon metallurgical plant since 1930. The paper details the companyÆs operational turnaround since 1995 and æThe 777 ProjectÆ which includes: two new mines, expansion and modification of the concentrators, expansion of the zinc pressure leach plant, a new zinc electrolytic cellhouse and the modifications to the copper smelter gas handling system to reduce ground level gas emissions.

Jan 1, 2000