The objective of this thesis is to optimise the fragmentation at Boliden Minerals open pit mine Aitik. Blasting is one of the main operations in mining, and its performance has a major impact on the overall economy of the mine. The fragmentation process affects not only the local productivity and unit costs of the mining department. It also affects the performance of the subsequent comminution ...

Aiming at predicting what happens in reality inside mills, the contact parameters of iron ore particles for discrete element method (DEM) simulations should be determined accurately. To allow the irregular shape to be accurately determined, the sphere clump method was employed in modelling the particle shape. The inter-particle contact parameters were systematically altered whilst the contact p...

Gearless mill drives are a well established solution for grinding applications in the minerals and mining industries. The paper describes the functionality and technical features of such drive systems as well as their advantages compared to other drive solutions. Due to the variable speed operation the grinding process can be optimized for ores with varying grinding properties. This leads to si...

Many procedures have been described (Umbreit et al., 1957) for the mechanical rupturing of yeast and bacterial cells. These techniques vary from simple hand grinding with abrasives to the use of extrusion or high speed shaking devices. These techniques, although generally satisfactory when dealing with small quantities of cells, are unsuitable for breaking larger quantities of cells required in...

Milling is one of the most energy consuming stages value production chain in many industries. To minimize specific required, new and more efficient devices circuits are designed dedicated optimizing control strategies applied. This research presents results innovative electromagnetic mill consumption reduction with supervisory on-line algorithm. The paper describes an algorithm that uses active...

In the present work, fine grinding of limestone was performed by using a super centrifugal mill (SC-mill), type bead mill. The feed sample contained particles below 75 μm in size ground crusher with slurry density 30 mass%. eff ects operational conditions including rotor speed, time, size, and mass beads on grindability were investigated, as well wear beads. evaluated through products 1 measure...

This study investigated the effect of grinding media on fine-grinding performance in wet tumbling mill. Comparative experiments between cylpebs and ceramic balls were conducted a laboratory ball mill under various conditions, such as different total masses, surface areas, numbers. The results indicated that produce slightly smaller instantaneous breakage rate than due to their small bulk densit...

Michaelis-Arbuzov reactions of S-aryl disulfide derivatives of 3'-thiothymidine or 5'-thioadenosine with tris(trimethylsilyl) phosphite proceeded in high yields to the corresponding phosphorothiolate monoesters. Subsequent hydrolytic desilylation and phosphate coupling were effected in one-pot using liquid-assisted grinding in a vibration ball mill. Novel 3',5'- and 5',5'-pyrophosphorothiolate-...

and Implications The aim of this study was to test if further grinding of corn DDGS is advantageous in terms of apparent total tract digestibility (ATTD) of DM, GE, nitrogen (N), and NDF in growing and finishing pigs. It was also tested to determine if ATTD was different between hammermill and roller mill grinding methods. There were 3 diets. Each diet consisted of 51% corn ground at 500 micron...