Particle and powder mechanics

The European EIT Rawmaterials project HARSHWORK develops technology to improve the efficiency in handling processes of raw materials such as copper or nickel, where the impact and wear of industrial components is very high. HARSHWORK aims to increase the competitiveness of mining companies and manufacturers of industrial equipment for this sector, as well as steel manufacturers and companies in the recycling sector.

Solid Mechanics has received founding from LKAB for a pre-study to identify properties for predicting the degradation/damage on pellets and fines generation in different types of flow in the production, transportation chain and storage. The project goal is to develop methods that will increase the possibility to implement modern modelling and simulation methods in product development processes.

Powder pressing is often a complicated process as the behaviour of the powder material changes with increasing density. Manufactures tend to produce components with more complicated shapes which demand complex pressing equipment and methods. This implies a better knowledge of the material response during the pressing process. Mechanical properties of powder materials changes dramatically from the beginning to the end of the compaction phase. Previous investigations have shown that powder transfer and high powder flow during filling affects the strength of the final component significantly.

One challenge met in many industrial processes is degradation of materials. LKAB as one of the world’s leading producers of the upgraded iron-ore products experiences varied degradation conditions during the processing of their products. Iron ore pellets are the main product of LKAB. Pellets come in different types depending on the requirement of the customer. Before transportation to customers the pellets are sintered in a rotary-kiln system to have full strength. The sintering process of pellets is central and highly important for the quality of LKAB’s products. Grate-kiln systems are used in order to oxidize and sinter pellets at temperatures up to 1400 °C. Unexpected failures of such systems are highly costly and causes production discontinue.

The research subjects Experimental Mechanics and Solid Mechanics have together with University of Oxford, UK been approved a four year project by Swedish Research Council. The project is called ”3D-analysis of compaction in granular materials” and the researchers Dr. Fredrik Forsberg Experimental Mechanics/LKAB, Assoc. Prof. Pär Jonsén Solid Mechanics and Dr. Clive Siviour Oxford University, UK will be working in the project.

The main objective of this project is to understand the processes of abrasion and load of overburden materials and plate structures. Create a model for wear in advanced materials flow calculations, in order to predict the plate lives in different applications.

To established further confidence in the numerical models from ModPulp a natural continuation is to work with the validation of the models. The work will provide information on the numerical models measure up or be improved. Another important aspect of modeling is to work with the scaling effects of the pilot mill trials and models of mills in full size. To use data from measurement on the center of gravity and torque measurements and validate numerical models of these results is also an important part of a continuation. It will be a new way to evaluate the dynamic effects in tumbling mills. Combined with the measurements made at LKAB in Malmberget these will provide a better understanding of the dynamic system that mills actually are.