The Next Generation of Monolithic Installation Technology: Continuous Mixing of Low Cement Castables for Wet Shotcreting Applications

Lengthy mixing times of low cement castables, when considered over the full volume of material to be installed, can contribute significantly to the timeline of a refractory installation. On construction projects, timing is critical. By reducing or eliminating the residence time inside the mixer, installation times can be reduced. This paper will examine the use of new equipment technology – the MX20-CM, a two-stage continuous mixer – to address this issue. Commercially available refractory castables based on high-quality CAC (calcium aluminate cement) were prepared three ways: (1) traditional batch mixer, (2) MX20-CM, and (3) Hobart mixer. When the castables’ physical properties are compared, the results show that material of comparable quality and performance can be produced on a continuous basis at a feed rate up to 25 tons per hour. By providing material in an asneeded manner, cost savings can be realized in an overall reduction in job timeline, waste, and manpower.