OCLC: 1006746520
PROQUEST: 304573543
The objective of this thesis project is to investigate thin coatings and spray-on liner products for use as ground support in the hardrock mining environment. The initial research work was undertaken by the Mining Industry Research Organization of Canada (MIROC) in the late 1980's. The MIROC research work was published and released to the industry sponsors after each phase of investigation. An enormous amount of chemical testing was completed by MIROC to provide the mining industry with a prototype spray-on coating, Mineguard™.
Mineguard™ is an innovative, polyurethane-based, spray-on rock lining material that is intended primarily for use in underground hard rock mines and for other geotechnical sites in order to provide rapidly-deployable area support coverage. A series of laboratory and in- situ mine assessment trials have been undertaken through MIROC and INCO's Mines Research Department to determine support and other physical response capabilities of Mineguard™ for various mining and geotechnical applications.
The majority of the research within this thesis is based on testing with the Mineguard™ coating, although it is clear that other new products will likely also prove to be viable materials for support of rock. Some of these new coatings are the Futura Rockguard polyurethane coating, FOSROC's TekFlex, Master Builder's new polymer cement blend materials, and ITW Foamseal's polyurea material.
This thesis presents a review of practical considerations concerning spray-on liners, as well as the results of several field case histories that illustrate various mining applications of this innovative support technique. This recent research is summarized within the following aspects of thin spray-on coatings:
From a technical viewpoint, the research involved investigation of the material properties and support mechanism of thin spray-on liners. From this work, the ideal material properties for ground support effectiveness have been proposed.
A generalized comparison of the support mechanisms has been made for: (a) thin spray-on liners, (b) shotcrete and (c) bolts and screen. Using this information, a liner capacity and a design guideline are proposed.
The operational considerations involve issues relating to the productivity and economic factors as well as the health, safety and environmental controls for underground mining and consideration of the flammability of polyurethane materials.
Based on the technical issues and operational considerations, the applications and limitations of spray-on liners have been recommended. The implementation recommendations are practical solutions relative to the current mining processes at INCO, with a vision of future applications to improve all aspects of hardrock mining. In particular, the use of spray-on liners for immediate support, with low materials handling, offers considerable merit for such applications as short-term ground support to speed up a conventional development process. In addition, other practical construction applications have been highlighted, for improvements to the mining operations in surface plants and within the underground environment.
Overall, the underlying finding within this research work is the increased understanding of how spray-on coatings can be used to improve the mining environment and mining processes.
The motive for the research is the strong conviction that spray-on liners have the potential to revolutionize the mining industry. This can be realized by:
Spray-on support also allows for the realization of automation visions for hardrock mining whereby a liner is used as sole support in fast-development headings.