Influence of jaw crusher parameters on the quality of primary crushed aggregates

A parameter study using a jaw crusher is designed to investigate the influence of feed gradation, feed rate, crusher setting and crusher speed on the crusher operation and the quality of the produced aggregates. The study is focused on the production of all-in large-size (top size >= 90 mm) aggregates, suitable for use in subbase and frost protection layers in a pavement structure. Aggregate quality is measured in terms of product gradation, particle shape and mechanical properties. Feed gradation, crusher setting and crusher speed affects the specific energy consumption during crushing. Particle shape is affected by all parameters; feed gradation, feed rate, crusher setting and crusher speed. Mechanical properties are least affected by the jaw crusher parameters, but sample preparation using laboratory crushing clearly affect mechanical properties. The results from this study provide valuable knowledge for the optimisation of single-stage crushing regarding crusher operation and aggregate quality. By adapting the crushing process to the available feed material and desired product, the quality of the crushed product can be optimised along with the crusher operation.