Sökning: "Rock fragmentation"

Visar resultat 21 - 25 av 35 avhandlingar innehållade orden Rock fragmentation.

  1. 21. Deformation and failure of hard rock under laboratory and field conditions

    Författare :Kelvis Pérez; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och berganläggningsteknik;

    Sammanfattning : The understanding of the fracture mechanisms and failure processes of the rock is an important requirement for the design of mining excavations and civil engineering constructions. The fracture process is necessary for the excavation and fragmentation of rock, but fracture of rock must be avoided and controlled to preserve the integrity of the construction. LÄS MER

  3. 22. Role of Fragmentation at the Production Level of a Sublevel Caving Operation

    Författare :Sohail Manzoor; Anna Gustafson; Håkan Schunnesson; Daniel Johansson; Javad Barabady; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och berganläggningsteknik;

    Sammanfattning : This research was conducted to evaluate the association of rock fragmentation with different unit operations of a sublevel caving (SLC) production cycle. Drilling, charging, and blasting, as well as the nature of the rock mass, can affect the fragmentation observed at the drawpoints. LÄS MER

  4. 23. Modelling the microstructure, the mechanical response of rock material and the relationship between them

    Författare :Margarida Taborda Duarte; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

    Sammanfattning : Rock material heterogeneity is one of most important intrinsic properties of geological materials. The need to quantify and model this heterogeneity is a key point for the prediction of the rock fragmentation behaviour through simulation. In this thesis both microstructure and mechanical heterogeneity are analysed. LÄS MER

  5. 24. On the Operational Efficiency in Open Pit Mines

    Författare :Ali Beyglou; Håkan Schunnesson; Pablo Segarra; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

    Sammanfattning : Open pit mines constitute more than half of global minerals production. Yet most of the large, high-grade, and close to the surface deposits have been depleted or are currently in production. Besides, volatility in commodity prices and stringent environmental regulations limit the up-scaling expansions in large open pits. LÄS MER

  7. 25. Towards understanding breakage and flow in sublevel caving (SLC) : Development of new measurement techniques and results from full-scale tests

    Författare :Matthias Wimmer; Pekka Särkkä; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

    Sammanfattning : Blast function, fragmentation and gravity flow are core elements for sublevel caving (SLC). For the ore recovery to be as high and the waste rock dilution as low as possible all three elements have to work as planned. LÄS MER