Geometallurgical characterization of the Kittilä gold ore deposit

• Main Author: Bis, Konstantinos
• Other Authors: Kangas, Lasse, Insinööritieteiden korkeakoulu, Leveinen, Jussi, Aalto-yliopisto, Aalto University
• Format: Master Thesis
• Language: English
• Published: 2018
• Subjects: comminution; crushability; geometallurgical testing; grindability; Kittilä; Northern Finland
• Online Access: https://aaltodoc.aalto.fi/handle/123456789/35446

Comminution testing is a key component to geometallurgical characterization of different ore types. Through comminution tests, valuable information is extracted regarding the breakage mechanisms of the rock, which can be used to enhance the processing operations, including ore blending, circuit design and mill optimization. Most geotechnical tests require large amounts of sample, expensive equipment and are very time consuming. Standard test methods like uniaxial compressive strength and fracture toughness are not considered appropriate in comminution characterization. Alternatively, simple and rapid methods have been used in this study to determine comminution indexes. The results from the comminution tests were used to characterize the grindability and crushability properties of six different ore types from the Kittilä Au deposit in Northern Finland. In summary, the tests which were conducted for this study include the Bond Ball mill grindability test, the Los Angeles abrasion test, the Point Load Strength test and the JK Drop Weight impact test. Additionally, the mineral composition, content and microstructures of the ore types have been determined through optical microscopy and the Scanning Electron Microscope (SEM). Statistical interpretation and correlations were carried out between the various tests and the modal composition of the six sample groups, using the statistical software IBM SPSS. From the results, the six ore groups were classified in the range of moderate hard crush to hard crush, while the grindability fluctuated between moderate hard grinding to very hard grinding. It was concluded that the mineral composition, textures and microstructures have as effect on the ore’s resistance to breakage mechanisms. Due to the simplicity and empirical nature of the comminution tests used in this study, the data cannot be used directly for mill circuit optimization. However, the data from this study can be implemented in future research for determining geometallurgical properties using rapid-remote ...