ROCK REINFORCEMENT
To improve bolting installation practices and installed rock reinforcement performance , and to meet the requirements of advanced mining company safety and efficiency expectation , the following systems were developed by Jennmar : n Mechanised bolting machine utilising a carousel of self-drilling anchors , J-Lok P polyester resin injection and nut tensioning through a boom indexing system n Mechanised bolting machine utilising a carousel of torque tension rebar / threadbar resin bolts , J-Wand polyester resin injection and nut tensioning through an indexing system n Fully integrated J-Lok P polyester resin injection on a Komatsu mechanised bolting machine n Platform bolter conversion n Twin-boom jumbo bolter with split-feed booms and J-Lok P polyester resin injection using various self-drilling anchor designs n Mechanised cable bolting machine utilising original equipment manufacturers ( OEM ) standard nylon grout tubes and J-Lok P polyester resin injection . The paper then detailed the development of a polyester resin injection for various rock and cable bolting applications , rock reinforcement design to support polyester resin injection , and comparisons of the performance of polyester and urea silicate resins in terms of material properties and application .
“ Polyester resins are the most widely used resin systems in different industries due to material availability , ease of use , low cost and excellent material properties . The operating service temperatures for polyester resins are wider than for other resin systems . Polyester resins are versatile because of their capacity to be modified or tailored during the manufacturing of the polymer chains . The principal advantage of polyester resins is a balance of properties ( including mechanical , chemical and electrical ), stability , lower cost and ease of handling or processing . For these reasons , Jennmar chose polyester resin for bolting injection applications .”
The authors add that the temperature effect on Part A and B of J-Lok P polyester resin appears to be relatively less significant . “ In cold weather , the resin and catalyst may be frozen . However , the low temperature will not affect the quality of the product and their functionalities remain the same once thawed . If ambient temperature is higher in summertime , viscosity of the J-Lok P Part A and B may drop slightly and sometimes filler particles may settle at the bottom of the intermediate bulk container ( IBC ). The quality of the resin and catalyst remains the same and minor solid-liquid separation is rectified by remixing resin in the IBC . If stored correctly , the shelf life of polyester J-Lok P resin in IBCs should exceed two years . However , it should only be used beyond the manufacturer ’ s recommended date after passing laboratory testing .”
The J-Lok P system is a specialised patented hydraulic , pneumatic or programmable logic controller- ( PLC- ) controlled pumping system . It comprises three main components : a highvolume resin transfer station , an on-board resin storage station and an injection module . Depending on the application and project requirements , system designs are modified to meet resin ratio , on-board resin storage volume , and carrier size and injection volume requirements . Polyester resin and catalyst transfer from bulk mobile handling systems to on-board resin is completed in approximately five minutes , assuming two 130-litre tanks are filled .
The cited advantages of employing the J-Lok P system , particularly in poor ground when using engineered solutions , are : n Improved quality control by reducing manual operator inputs . n An installed single-pass system designed to meet corrosion , dynamic and static requirements . n Designed ground support that economically mitigates risk with minimal future unplanned rehabilitation . n Products are designed using industry best practice and innovative methods . n A fit-for-purpose system that meets life of mine and design requirements .