Binder-free tableting experiments on manganese oxides and industrial mineral powders.

Cold, binder-free tableting experiments under controlled pressure (0-450 MPa), water addition (0-10 wt.%) and pH (4, 11) were performed on powder of pyrolusite ore concentrates, refined hausmannite, bentonite, kaolinite, as well as blends of those materials. It has been shown that increased pressure was beneficial for agglomeration of oxide materials, but pressure > 250 MPa triggered an elastic recovery in the clay minerals. Water addition up to 4 wt.% improved tabletability, increasing diametral resistance and reducing elastic recovery and fines generation. Amounts above 6 wt.% decreased diametral resistance. The presence of layered-structure minerals (such as montmorillonite, kaolinite, lithiophorite) appeared to be key to determine the agglomeration potential of a sample. This study also showed that tableting provides good performances for recycling industrial manganese oxide fines by obtaining industrial-grade resistance for tablets made with an 80/20 pyrolusite concentrate/hausmannite blends and 4 wt.% H 2 O. Unlabelled Image • Tableting presents an alternative recycling process for Mn processing fines. • Mn refining and laterite ore fines can be recycled at 20/80 wt.% with 4 wt.% H 2 O. • Soft, plastic material with high specific surface area is key for good tableting. • Lithiophorite acts as natural binder in tableting due to its layered structure. • Prediction of fines tableting behavior requires a deep understanding of materials. [ABSTRACT FROM AUTHOR]