| 1. |
- Evertsson, Magnus, 1967, et al.
(författare)
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Monitoring and validation of life time prediction of cone crusher with respect to loading and feeding conditions
- 2016
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Ingår i: Comminution 16. - 9781510826670 ; 904 (1 Vol)
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Konferensbidrag (refereegranskat)abstract
- The interest and need for compressive crushing in gyratory, cone and HPGR crushers are increasing since ores become more competent and more difficult to break. Compressive crushing is energy efficient as a consequence of the crushing principle and the imposed stress-state. The stress variations can be described by stress amplitudes and it is a known fact that many different materials, components and machines suffer from cyclic loading which shortens the service lifetime. This phenomena is explained by density variations of the particle beds in the equipment which in turn originates from particle segregation and feeding alignment. The phenomena is often called fatigue and the consequence is premature breakdowns and a relatively shorter lifetime than expected. In this paper, a previously developed theory for lifetime assessment of cone crushers will be used as a foundation for evaluation of full-scale operating cone crushers in minerals processing plants. Lifetime is calculated as a consequence of the load spectrum. The data shows that improper feeding conditions will substantially decrease the lifetime of the crusher equipment leading to excessive operating costs. An adequate control system should be able to recognise the hazardous lifetime decreasing overloads and to warn the operator. There are sometimes conflicting interests in the control strategies between production yield (process requirements) and crusher protection.
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| 2. |
- Guldris, Lorena, 1983, et al.
(författare)
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'Mineralogical characterization, reduction and liberation analysis of tungsten ore
- 2016
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Ingår i: Emerging Trends in Minerals Engineeing.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Due to the raising global demand for rare earth minerals there is an increased need for development of more efficient extraction processes of such materials. Comminution models commonly predict size reduction with the focus on a single component, but few models integrate the mineral composition. This paper focuses on defining a multi component model, combining the size reduction and the mineral liberation. In this study, compressive breakage and liberation analysis experiments were conducted on a Tantalum ore. The work is divided into two stages, firstly the methodology of fitting measured data into a size reduction model, and secondly the multi component modelling where the liberation results are integrated into the size reduction model. Results from the work show that in order to address multi component modelling it is necessary to focus on dominating factors such as dominating quantities of different minerals. It was also seen that the model can be used for determining the choice of compression ratio in crushing for optimizing liberation.
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| 3. |
- Guldris, Lorena, 1983, et al.
(författare)
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Modelling Reduction and Liberation for Rare Earth Minerals Applications
- 2016
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Ingår i: MEI 10th International Comminution Symposium (Comminution '16).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Due to the raising global demand for rare earth minerals there is an increased need for development of more efficient extraction processes of such materials. Comminution models commonly predict size reduction with the focus on a single component, but few models integrate the mineral composition. This paper focuses on defining a multi component model, combining the size reduction and the mineral liberation.In this study, compressive breakage and liberation analysis experiments were conducted on a Tantalum ore. The work is divided into two stages, firstly the methodology of fitting measured data into a size reduction model, and secondly the multi component modelling where the liberation results are integrated into the size reduction model.Results from the work show that in order to address multi component modelling it is necessary to focus on dominating factors such as dominating quantities of different minerals. It was also seen that the model can be used for determining the choice of compression ratio in crushing for optimizing liberation.
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| 4. |
- Guldris, Lorena, 1983, et al.
(författare)
-
Reduction and fracture analysis of a tungsten ore and its use for fundamental liberation modelling
- 2016
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Ingår i: Procemin 2016. 12th International Mineral Processing Conference.
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Konferensbidrag (refereegranskat)abstract
- Nowadays there are numerous tungsten applications and uses, due to this the global demand for tungsten has increased the extraction and production of this rare earth mineral. The liberation of tungsten is achieved by using comminution equipment, e.g. crushers, there is a lack of knowledge how tungsten is liberated by means of compressive breakage. Even though it is possible to use find comminution models for explaining the size reduction, there is also need to implement a mineral liberation model into theses comminution models. This paper will focus on a fundamental model that combine and integrate the size reduction with the mineral liberation in early stages of the breakage process.This work focuses on analysing the liberation characteristics that occur by means of interparticle breakage. The work includes two parts, firstly the integration of the measured data into a size reduction model, and secondly a reflexion and understanding of the liberation and fracture mechanism during the breakage.Results from the work show that in order to address multi component modelling it is necessary to focus on controlling factors such as dominating quantities of different minerals, breakage mechanism in different bounded minerals and how this is connected with the liberation of them. It also was observed that the model could be used for determining the choice of the compression ratio in crushing for optimising liberation.
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