Fundamental knowledge of the dielectric properties of vermiculite, its interaction with electromagnetic fields and bulk materials handling technology was used to design and construct a continuous high throughput microwave processing system operating at 2.45 GHz. The design methodology used to engineer the system is reported. Experimental demonstration of the effects of microwave energy on the product bulk density is provided for the three most industrially relevant grades of material and it is shown as to how the performance of the system is significantly better than conventional exfoliation technology, in terms of produced bulk densities, energy efficiencies, temperature of the product and plant footprint. (C) 2012 Elsevier B.V. All rights reserved.