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In submitting the accompanying sketch and description, the writer mentions that he has found this "gadget" a useful assay office adjunct.He believes that some millmen and assayers have been confronted, from time to time, with large samples of mill pulp for assay purposes and that although the commonly used method of coning and quartering dry sample is simple and effective, provided the samples are of reasonable proportion, the operator is frequently confronted with samples of pulp, sometimes up to 50 gallons. The writer stresses the advantage of being able to handle these samples. This fact inspired the design of the "gadget,"which was developed at the Kalgoorlie State Battery and has been found to give very reliable results. It has considerably eased the work of the assay office.Description. - A cone of suitable dimensions according to requirements (this one is about six gallons' capacity) is mounted on a light angle-iron frame and has a small hand-operated agitator paddle let into it far mixing purposes. The agitator and head frame are removable to facilitate cleaning. Four outlet pipes at the bottom at right angles to each other are controlled with one common plug, externally operated for discharging the pulp.Each operation of the machine delivers four equal parts; one or more of these can be used for further division as conditions require. Samples can thus be reduced to suitable assay room size in a few minutes.The dotted lines, enclosing the shaded portion, represent the four-bladed paddle.Each paddle is slotted with three parallel slots. Unshaded portions represent slots.

Jan 1, 1939

Sampling systems are never perfect. They all have some bias and give variable sampling errors. The ways of thinking about bias and precision should be different before and after construction (or reconstruction) of a sampling system. Before a sampling system is constructed, the fundamental error variance can be estimated using GyÆs formula or by doing test work on the material to be sampled. The component of sampling variance which varies with the number of sample increments can be computed for the expected patterns of grade variation. The smallness of the bias can be checked using discrete element modelling, by checking that the proposed design complies with clauses in standards, or by copying an existing sampling system that performs well for similar material. After a system has been constructed, sampling precision can and should be monitored directly. Anyone claiming to take responsibility for a sampling system should know its precision. Bias could be checked by comparison to a more accurate sampling system, such as stopped-belt sampling, under conditions where bias seems most likely. However, it is more practical to conduct regular checks that the system is still operating as designed, that the design is still appropriate despite any changes to material flows, and that sample masses are consistent with the correct operation of the sampling system. If precision is not regularly assessed then it should be assumed to be very poor. If a sampling system is not regularly inspected then it should be assumed to be biased.

Jan 1, 2008

Mineral exploration management has undergone major changes particularly in the last decade. Parallel to these changes in management, and partially responsible for them, have been the changes in governmental laws and regulations at both National and State levels reinforced by a highly competitive climate created by the exploration boom in Australia. The influence of overseas methods and approaches have been married to the Australian techniques resulting in a management climate which is not only familiar with the technical aspects of exploration, but is also familiar with the personnel, economic and legal phases associated with the expenditure of very large sums of money. The utilization of all the geosciences coupled with mathematical models and computer techniques for pre-selection and assessment of areas are now normal aids used in management decisions. Management techniques developed and being developed will ensure that successful exploration will be carried out if sufficient incentives are guaranteed.

Jan 1, 1974

Development of a small ore body to 137m below surface was carried out in sixteen months driving 610m of 1:5 decline.

Jan 1, 1973

In the face of intense global competition and other business pressures on coal miners, ongoing quality initiatives and continuous process improvements are needed to enhance business performance. By viewing a minesite in terms of key processes, rather then departments, and employing innovative technologies and better applying organisational resources, there exists enormous potential to achieve reductions in process cost and time.

Jan 1, 1998

Hydrocyclones are widely used in both mining and various industrial sectors. Considerable fundamental research work on the modelling of hydrocyclone classifiers has been carried out through the past 25 years. Based on the similarity principle, the hydrocyclone classification was taken as a whole physical process and a group of similarity numbers were obtained with the help of dimensional analysis in this paper. Then, the functional dependences of the similarity numbers have been established. The variables optimisation was carried out with the multiple objectives linear planning programs developed in this study.

Jan 1, 1993

By Burchell S, McGregor K

The process of design, measurement and review is essential if blasting is to continuously improve to meet the increasing productivity goals of most mining operations. To achieve continual improvements, many operators are turning to contractors to provide the necessary technology. Under this arrangement, the contractor becomes the supplier of a service rather than products and assumes some of the risks associated with blasting by guaranteeing the end result. If contractors are to obtain significant productivity improvements they must continuously improve every aspect of their business.

Jan 1, 1994

During the period May to July 2003, East Mine overcored and recovered from goaf edges a total of 55 1.8 metre CVX grade bolts to analyse installation quality. Some 95 per cent of the pneumatically (hand-held Gophers) installed bolts show gloving, with 75 per cent showing gloving of at least one-third of the effective bolt length. Hydraulically installed (continuous miner-mounted bolting rigs) bolts show in some areas less gloving but do have significant unencapsulation lengths. Trials of newly developed bolt end profiles show considerable improvements in eliminating gloving but do show variable and unacceptable variations of unencapsulation.

Jan 1, 2003

By Equivar J, Mirabal C, Pyper R

In 1984, work was started to determine the viability of heap leaching silver-containing waste dumps from Cerro Rico near Potosi - Bolivia, at an elevation of 4300 meters (14 100 ft.). The result today is an unusual heap leach utilizing fine crushing, grinding, and agglomeration to process 1000 tonnes per day of ore containing 200 g/tonne silver. The unique metallurgi- cal, economic, and political factors will be discussed which led to the decision to build a heap leach rather than a conventional agitation leach plant. Capital and operating costs will be given along with some of the uncommon process design and equipment problems encountered while developing the operation.

Jan 1, 1991

Project evaluation is completed through individual studies covering technical and financial aspects of the mine to market. These studies are completed at various levels of detail depending on where the project evaluation is in the projectÆs life cycle. The competency of the studies varies in relation to the quality of data, level of the skills employed, control, management and reporting structure. The focus of this paper is managing elements of the study, looking at the cost of opportunity to influence the project, against the value added. Selection of the study manager and study teams is central to getting an integrated project evaluation addressing the correct issues completed on time. Retention of key personnel can reduce rework which, in turn, can reduce time and cost impacts. It is important to have a work breakdown structure at the outset so that the study teams have a common numbering and naming system that will integrate areas, equipment, budgets estimates and accounts. Having set up the evaluation groups and provided training in the study procedures, understanding the scope and schedule are vital elements in producing a project evaluation that addresses the opportunities and the risks of the final project. Arriving at an accurate capital budget requires integration of the research controlled through common systems. Project evaluation process must also address how the project is to be delivered.

Jan 1, 2007

Powered support plays a major role in longwall mining and improper selection may lead to a disaster. While different countries follow different norms, a universal approach is needed to be developed. For this purpose, a computer program C-ALPS

Jan 1, 1998

By Churchill J

A suite of software programs has been written to provide the field engineer or geologist with the capability to collect and store data directly into small, portable handheld computers. This allows the engineer and geologist to collect data in a more efficient manner as the data is collected in sequence and is verified at the time. Typical applications for this software include geological and geophysical logging, trucking surveys, mine surveying, condition monitoring, ventilation surveys and maintenance systems. The software allows the user to construct his own electronic notebook by structuring data input to the computer in a similar manner as is now done on pre-printed forms. The user can store all valid entry codes or numeric ranges in a dictionary and all data inputs made are validated against this dictionary. Once constructed the user may call the electronic data sheet into the unit and collect data which will be stored into the unit which has the memory capacity to record data for up to periods of 60 hours. The data can then be automatically transferred to mini/microcomputers for immediate analysis and report generation. The software may be used on a variety of handheld computers.However the generally rugged environments found in the mining industry limit the choices. In particular the authors have selected a unit weighing a little over one kilogram, which is rugged enough to fall off an underground survey vehicle, and survive when accidentally immersed in water,without losing data. This paper describes the software developments in detail. The project development work to produce this system has been funded by a grant from the Australian Mineral Industries Research Association and is supported by a number of large Australian mining companies.

Jan 1, 1986

The intention of this paper is to give a review of the present status of lignite mining in the so-called Gulf States in the United States of America, namely Texas, Arkansas, Mis- sissippi and Louisiana. The situation in these states is similar to the situation in Australia in that "Strip Mining - 45 m and Beyond" repre- sents the main technical problem to be over- come in the near future. The solution lies in the application of the bucket wheel excavator.

Jan 1, 1981

The expense of mine environmental and planning process approvals is a fundamental and proper part of mine planning and feasibility costs. It is not a cost that should be the subject of challenge nor is it a cost that should be avoided. However the additional process approval costs incurred by bureaucratic delay, process duplication and administrative incompetence is a scandal and a deterrent to investment.

Jan 1, 1992

By P McCarthy

Many mining operations developed in the last 15 years have not performed to expectations. Problems experienced include lower than planned development and production rates, geotechnical/stability problems, unplanned dilution, reduced metallurgical performance and unbudgeted capital/operating costs. Most of these problems can be directly attributed to decisions made on the basis of geoscience interpretations and estimates. Recent case studies continue to provide examples of unplanned events linked to the use of geoscience information. These studies illustrate the need to improve the way geological information is used in mine feasibility and operations. Comprehensive assessment of the consequences of inappropriate technical decision making is still rare; however, the information that is reported highlights the significant financial impact on a companyÆs bottom line.

Jan 1, 2006

Sasol Roche Blasting Services (SRBS) and its former owners have been in the process of developing and utilising low-density explosives over the last ten years. Many blasts have been fired in varying strata types in a number of mining operations. This has led to a good understanding of the product and the best methods to exploit its characteristics when designing blasts. Unlike some other low-density products, SoftLOAD« is a homogeneous mix that is easily handled and able to be loaded at high load rates. This paper discusses the physics of SoftLOAD« low-density explosives and how through correct utilisation, blasting outcomes can be significantly improved. It also touches on the various side benefits that can provide the blast designer with a more controlled blast.

Jan 1, 2004

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

This paper presents the results of studying the influence of catastrophic failures arising in mines, on the behaviour of mine ventilation systems. It is very important to take account of this influence for the stable operation of the system and to ensure mine safety when mining underground coal and ore deposits.

Jan 1, 2003

More than in any other way, the community judges the minerals industry by its environmental performance. Minerals Council of Australia web site www.minerals.org.au/media/code Time is overtaking us. What was good enough yesterday is not good enough today. What may be acceptable today wonÆt be tomorrow. So we need to leap forward. We need to begin to move towards sustainability. Dick Zandee, Managing Director, Placer Dome Asia Pacific The competition for access to exploration and mining opportunities is intense. So is competition for the best people, capital and community support. Poor environmental performance damages a companyÆs ability to attract these. Quite simply, good environmental management is good business. Hugh M Morgan AO,Chief Executive Officer,WMC Limited. Decisions made by private industry and international corporations are increasingly determining the fate of the environment. ...Nothing could be more shortsighted than for todayÆs conservationists to neglect cooperation with business and industry as a means of moving company philosophy and public accountability ahead in favour of the environment. Dr Claude Martin,Director General,WWF International The four quotes above well illustrate the challenges faced by companies and conservationists in attempting to achieve the societal goal of sustainable development. That this aspirational goal itself is far from clearly defined, although it has been widely accepted and endorsed by governments, business and civil society, exacerbates the challenges. Sustainable development has as its central thesis the integration of environmental, social and economic policy. Its attainment by business has been described John Elkington (1998) as the pursuit of the ætriple bottom lineÆ - the achievement of social and environmental targets, in addition to the traditional economic bottom line. It is self-evident that business is both competent and comfortable defining and measuring economic performance and reporting that performance to internal and external audiences. As long as information has been prepared according to the established standards of measurement and reporting of economic performance, all audiences can have confidence in its accuracy. Business does not enjoy the same competence and comfort with regard to social and environmental performance. This is no startling condemnation of business, any more than it is a criticism of governments, non-government organisations (NGOs) or academia. It is a statement of fact that the tools to allow for credible definition and reporting against the other two components of the ætriple bottom lineÆ have yet to be fully developed and are, therefore, far from being widely accepted. Crucial to achieving sustainability is the ability to measure progress toward the goal. The task is to develop means to define appropriate performance standards and to credibly measure and report company environmental and social performance against those standards.

Jan 1, 2000

By D Lees

Safety is paramount in the underground mining environment. The mining industry has for many years focused on injury prevention in the workplace through procedures and training. In the area of control of major accident events that could result in single or multiple fatalities, and serious injuries, the mining industry approach has concentrated mainly on past experiences and lessons learnt. However, in the last 20 years, other high hazard industries, such as the chemical process industry and oil and gas industry have developed the Safety Case approach, using systems safety techniques and risk assessment as a means of identification and control of major accident events. The Safety Case approach is now being introduced into Australian underground mining. This paper describes the Safety Case approach and how this can be adapted to underground mining. This is a holistic approach and assists in ranking significant risk contributors and prioritising risk management efforts. The discussion includes how the Safety Management System interfaces with the Formal Safety Assessment in effectively controlling the hazards. It provides examples from actual case studies conducted by KBR, and suggests ways forward for the industry.

Jan 1, 2003