Vermiculite is a naturally occurring mineral. When crushed, graded and fed into a hot furnace (1,200 oC or 2,200°F), the vermiculite expands or exfoliates to produce a lightweight particle that is then used as an insulating and fire retardant fill. The process requires a very rapid heat transfer to the particles to promote as large an increase in particle size as possible to give low densities. Historically, vertical shaft and rotary kilns have been used to exfoliate vermiculite.The TORBED reactor has shown itself to have unique capabilities in this application in producing higher quality, lighter and more consistent product with lower energy consumption. High heat and mass transfer and precision of control with the TORBED reactors have provided these advantages. Most important, the TORBED process provides more saleable product per unit of raw material fed i.e., a higher yield. The TORBED process is in successful operation in 11 major production plants in Europe, USA and Japan. Throughputs vary according to raw material grading but typically range from 1-5 tonnes per hour.
For further information about the TORBED ability to exfoliate vermiculite, see: