TY - THES

T1 - Prediction of particle shape in aggregate production

AU - Lindström, Anders

N1 - embargoed until null

PY - 2011

Y1 - 2011

N2 - The objective of this research has been to develop a method and a model that can be used to predict the shape of products that are typically produced by a tertiary or quaternary cone crusher where the demand of the particle shape is the highest. The model should also be able to be integrated in the PlantDesigner software that is currently used to produce flow sheets with equipment load, capacities and product sizes. Today there is no reliable method available that can be used to predict particle shape but still process guarantees including particle shape has to be written. The main motivation for this project work is that it can reduce risks associated with sales guarantees and another benefit is that the gained knowledge contributes to realize Sandvik’s ambition of being the recognized leader in improving profitability for the construction industry. The test center at Sandvik SRP in Svedala receive raw material samples from quarries placed all over the world and since 2010 the raw material test include analysis of particle shape after the samples have been crushed in a laboratory scale jaw crusher. The first part of the project has been used to characterize raw materials in the existing data base according to their particle shape. A raw material specific parameter that can be determined by a standardized test method has been identified. This parameter has been added to an existing model for flakiness index prediction (1) in order to improve the accuracy. After comparison with field test results the model has been further developed so that it can predict both flakiness and shape index with good precision for particle sizes near the close side setting of the cone crusher. The model should be considered to be a beta version that is ready to be implemented in the expert version of PlantDesigner that is exclusively used by a handful of experienced users. A limitation of the model is that it cannot handle maximum values in a satisfactory way and therefore the users of the model need to be able to identify when the results are realistic or not. This is however not an unsolvable problem and will probably be handled in future versions. Future work of improving the model should also include more field tests from quarries with different material types as well as different feed size and crusher settings. Other parameters that could influence the particle shape such as feed length, eccentric throw, crushing chamber geometries etcetera has not been considered in this work.

AB - The objective of this research has been to develop a method and a model that can be used to predict the shape of products that are typically produced by a tertiary or quaternary cone crusher where the demand of the particle shape is the highest. The model should also be able to be integrated in the PlantDesigner software that is currently used to produce flow sheets with equipment load, capacities and product sizes. Today there is no reliable method available that can be used to predict particle shape but still process guarantees including particle shape has to be written. The main motivation for this project work is that it can reduce risks associated with sales guarantees and another benefit is that the gained knowledge contributes to realize Sandvik’s ambition of being the recognized leader in improving profitability for the construction industry. The test center at Sandvik SRP in Svedala receive raw material samples from quarries placed all over the world and since 2010 the raw material test include analysis of particle shape after the samples have been crushed in a laboratory scale jaw crusher. The first part of the project has been used to characterize raw materials in the existing data base according to their particle shape. A raw material specific parameter that can be determined by a standardized test method has been identified. This parameter has been added to an existing model for flakiness index prediction (1) in order to improve the accuracy. After comparison with field test results the model has been further developed so that it can predict both flakiness and shape index with good precision for particle sizes near the close side setting of the cone crusher. The model should be considered to be a beta version that is ready to be implemented in the expert version of PlantDesigner that is exclusively used by a handful of experienced users. A limitation of the model is that it cannot handle maximum values in a satisfactory way and therefore the users of the model need to be able to identify when the results are realistic or not. This is however not an unsolvable problem and will probably be handled in future versions. Future work of improving the model should also include more field tests from quarries with different material types as well as different feed size and crusher settings. Other parameters that could influence the particle shape such as feed length, eccentric throw, crushing chamber geometries etcetera has not been considered in this work.

M3 - Master's Thesis (University Course)

ER -