Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 ACARP PROJECT C17004 TOUGH SKIN – A SPRAY-ON POLYMERIC REPLACEMENT FOR ROOF & RIB MESH Chris Lukey, Ernest Baafi, Jan Nemcik, Ian Porter School of Civil, Mining & Environmental Engineering Faculty of Engineering, University of Wollongong Roadway Development Operators’ Workshops March 2009

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Objectives To develop an alternative to steel mesh that: *Provides an effective skin confinement measure equivalent or superior to that of steel mesh *Requires minimal human intervention in its installation *Removes personnel from the immediate face area *Enables higher underground roadway development rates to be achieved *Is safe to use *Is cost effective The focus of our work is the development of a polymer- based alternative that can be spray-applied

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Why do we need an alternative to steel mesh? Currently steel mesh is installed manually Automatic self-drilling bolt technology cannot go ahead efficiently while mesh installation is a manual operation A recent survey of roadway development practices has identified a need for an alternative to steel mesh, the installation of which can be automated Automation, along with automatic bolting, will remove personnel from the face area and allow greater rates of roadway development

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Polymer Skin Properties Cure Characteristics - sets in a few seconds and can be bolted through Mechanical Properties - tough with some flexibility - adheres to strata to provide additional reinforcement Flow Characteristics - spray viscosity, followed by rapid viscosity increase (cure) immediately after application to avoid slumping Fire Retardant & Anti-static Environmental & OH&S Issues - no toxic or irritant emissions before, during or after cure

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Occupational Hygiene - effect of components and product on humans - consult an occupational hygienist with coal mine experience - improve understanding re Section 63 approval process Other Issues & Current Work

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Approval for Underground Testing (Section 63) Use of polymeric materials underground requires approval under Section 63 Range of tests required for LOBA approval (Germany), followed by further testing at MSTC (Thornton) Can take 2-4 years to obtain approval Most requirements are relevant to use of urethanes Negotiations initiated with DPI to establish appropriate approval regime Determination of airborne emissions during spray/cure - Headspace test - Wind tunnel spray tests Other Issues & Current Work

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 To GC-MS Sample (2g) 8cm Only one material is of OH&S and environmental concern Headspace Emissions Test

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Fan Unit Air “Straightener” Tunnel Wind Tunnel Spray Test

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Spray Chamber Filter Monitor Chamber Wind Tunnel Spray Test

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Concrete Pavers Spray Gun Wind Tunnel Spray Test

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 First test conducted with minimum permissible air velocity (0.5m/s) to simulate worst-case mine ventilation scenario Air samples collected: * During spray * Immediately after spray * After one further hour whilst maintaining ventilation in the tunnel Successfully sprayed and cured a developmental formulation No reinforcement included Minimal odour detected Quantification of off-gases Wind Tunnel Spray Test

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Lab-scale testing - odour test (wind tunnel) - combustion products - temperature increase of sprayed material when curing - methods for introduction of reinforcement - product optimisation Laboratory pilot-scale tests - application of fully-optioned product - proposed to build test gallery at UoW - includes pilot testing of automation options Final pilot-scale tests conducted at Londonderry - spray using reinforcement - mechanical properties - emission data Future Work

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Conclusions A polymeric alternative to steel mesh offers a number of advantages: * Can be coupled with automatic self-drilling bolts * Entire roadway support process can be automated * Manual handling of mesh can be eliminated * Roadway development rates can be increased We have demonstrated that a viable polymer-based alternative to steel mesh, that can be applied automatically, can be developed

Faculty of Engineering University of Wollongong Roadway Development Operators’ Workshops March 2009 Acknowledgements University of Wollongong Research Council ACARP Anglo Coal Australia Pty Ltd Austar Coal Mine Pty Ltd BHP Billiton Illawarra Coal Ltd BMA Coal Operations Pty Ltd Gary Gibson and Associates Gujarat NRE Pty Ltd Helensburgh Coal Pty Ltd Oaky Creek Coal Pty Ltd Rio Tinto Coal Australia Pty Ltd Springvale Coal Pty Ltd Xstrata Coal NSW Pty Ltd