Through its partnership with The University of Nottingham, UK, e2v has produced the new industrial microwave ProWave® vermiculite processing systems that utilizes patented technologies to offer a multitude of benefits to the industry. Improved energy consumption is of critical importance to processing and manufacturing industries; the energy consumption of the e2v ProWave system is around 150 kWh/tonne, depending on the grade of vermiculite and desired yield, this represents a potential energy saving of up to 90 percent from a traditional furnace based system.
e2v’s ProWave marketing manager, Paul Downey, commented, “Our new ProWave systems have the potential to completely change the way bulk material is processed, in terms of energy efficiency, cost and flexibility. As a ‘green’ production process, microwave systems can also make a significant positive contribution to an organization’s environmental responsibilities; comparative studies have shown the microwave process to reduce energy consumption by approximately 90 percent and reduce carbon footprint by 85 percent.”
Due to the nature of the technology, microwaves selectively heat only the water contained within the layered mineral structure. The mineral cannot therefore be ‘overcooked’, which is claimed to result in an unprecedented quality, consistency and yield of final exfoliated product. With the ProWave system, products can be optimized by blending multiple grades and adjusting the expansion ratio to suit the final application. This is achievable through the control of the electric field strength. Bulk density can be as low as 80 g/litre, so more volume can be produced from the same quantity of raw material – the ProWave system typically producing 12.5 m3 per tonne of raw vermiculite (@ 80 g/litre).
One of the major challenges in conventional vermiculite exfoliation is the huge volume of hot gas present in heated furnaces and the resulting energy consumption of dust and fume extraction. This can be a significant proportion of the energy used relative to the thermal processing itself but not with the ProWave system as a simple extraction system is supplied as part of the solution. The production capacity of the e2v ProWave machines are specified at a nominal 1 tonne per hour. Also the system is immediately available for processing upon switch on and as the expanded material exits the process at about 150°C it can be immediately available for packaging.