Coal Preparation » General
ACARP commissioned this study into maintenance issues of coal preparation plants, with the aim to identify areas where research may result in potentially substantial improvements.
The scope of the study included:
- Review current maintenance practice
- Assess approaches to condition monitoring
- Review of wear resistant materials.
The study was carried out by a combination of:
- Telephone contact with all plants in Australia
- Direct interview of maintenance management supervisors at selected plants.
- Interview of selected suppliers of maintenance intensive equipment, eg centrifuges, pumps and screens.
- Consultation with materials suppliers, regarding management of wear and tear.
Being the result of a survey, this report is a series of findings.
- Even with generous allowances for local circumstances, geography and other constraints, the industry has a huge unused capacity in the order of well over 100 million tonnes per annum. The need for capacity cannot be used for justification for R&D.
- Maintenance accounts of 41% of washing costs.
- The best achievable cost savings from longer equipment life and less maintenance labour are estimated at between 30 - 50 cents per tonne of feed. There is no single area, other than wear related expenses, which could have a major impact on this potential saving. For maximum savings all areas of maintenance need to be improved.
- Research into maintenance problems can be justified only by improved productivity through reducing delays, or reduction in operation costs.
The majority of plants have a computer based maintenance management system. In larger groups the company selects the overall management system that also handles plant maintenance. Plant maintenance is not the main purpose but only a relatively small part of the system.
Single site companies and smaller plants select the system to suit maintenance specifically. None of the systems considered have received complete approval by plant managers. The main complaint is that systems are unfriendly, intimidating and cumbersome to use. A "snap sample" of users shows that there are several systems that are simpler and relatively cheap for use by single site operations. Careful selection and thorough training are essential for the successful application of any system. The availability of simple systems at reasonable costs negates the justification for any R&D for a computer based maintenance management systems.
Manufacturers and designers were criticised for their slow responses to adopt modifications and improvements made by plants.
Every manager interviewed considered most of their problems manageable given sufficient resources and budget.
From the responses the main conclusion is that only wear stands out as a topic that causes most concern and represents the most frequently attended and costly parts of the maintenance system. All other issues appear to be concerns for manufacturers and suppliers, or a matter of adequate resources at plant level.
The development of superior wear materials is suggested for research. Research should be with a reputable commercial organisation or with an academic or research organisation that has the key expertise in this field. Composite materials may be a promising target. Benefits would extend into all areas of the mining industry, funding may be joint by other interested parties.
The compilation of a comprehensive guide of wear materials available in general and in use by the coal industry in particular is recommended.
There is a genuine need for a simple user friendly management system based on simple computer techniques. The survey results suggest that there are several relatively simple systems available for smaller single site plants. Careful selection and thorough training should ensure that one of these systems could be successfully implemented. No R&D could be recommended for the development of management systems.