Laboratory Facilities and Pilot Plants

Even though, as presented above, certain characteristic relationships have been developed for many agglomeration methods, scale-up is a serious problem. Furthermore, aging has very often a marked effect on the results, because binding mechanisms rely on chemical and physical interactions at the surfaces of particles to be agglomerated and, if applicable, with the binder component(s). Therefore, a representative material which is several days or weeks old and may have to be reheated, re wetted, dried, or delumped to bring it back to a comparable condition as found in the real plant environment may yield completely different results than those found later in-line. This means that not only tests must be carried out with representative samples of raw materials and, if applicable, binders but pilot plant evaluations on site and/or in-line should also be considered if the risk of a new application is to be minimized. 

Therefore, nearly all manufacturers of agglomeration equipment maintain rather elaborate laboratories, often with large scale equipment to avoid scale-up problems. These test facilities must also include peripheral equipment such as mixers, driers, heaters, crushers, screens, etc. For cost reasons, in most cases no continuous operation of an entire production line is possible. To simulate expected plant characteristics, a certain amount of fines may be recycled to the agglomeration unit. The amount and typical size consist of the recycle stream will be determined and, after simulated production, will be mixed with the fresh feed to evaluate the influence of this feed component on projected plant performance. 

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