Premium fuel production from coal and timber waste

Despite the availability of advanced technologies to recover nearly all of the coal in the -150 ?m size fraction, a significant amount of ultrafine coal is currently being lost to waste impoundments due to product moisture and handleability concerns. Simultaneously, the waste generated from timber mills that produce materials for the mining operation is being stored, in many cases, near the waste coal storage areas. Both waste materials represent a valuable energy resource. In an on-going project, coal recovered from plant waste streams is being combined with wood waste and briquetted to produce a premium fuel for the steam market that is easy to handle. An extensive study aimed at identifying the most effective binders and optimizing binder concentration has been conducted with the goal of maximizing briquette strength, weather resistance and wear resistance through abrasion. Using the identified binders and their optimized concentrations, a statistically-designed test program was performed using a continuous briquette unit. Three lots of briquettes produced under the optimized conditions with different binders were evaluated in a stoker combustion unit to quantify combustion characteristics and emissions.. The findings of the investigation will be presentation and discussed in this publication.