In many industrial processes where bulk materials are handled attrition can occur. Depending on the situation, attrition may be intentional (e.g. blasting, crushing, grinding, etc.) or unintentional (e.g. handling, screening, loading, transporting, storing, etc.). In this article, attention is centered only in the unintentional and unwanted attrition caused by impact when filling a bin, stockpile and/or ship hold with solid particles of different nature, size and/or density.

Also, a novel coefficient of attrition is proposed to quantify the tendency of a material to break into smaller pieces as a result of impact when falling from some height onto a steel plate and onto a bed of the same material. This coefficient is based on sieve measurements of the particle size distribution obtained before and after attrition occurs. Results from laboratory scale tests are presented, and compared with field data, for diverse bulk materials such as sinter, coke, fertilizers and salt crystals.