Sökning: "Mining and Rock Engineering"

Visar resultat 11 - 15 av 168 avhandlingar innehållade orden Mining and Rock Engineering.

1. 11. DEM Modelling and Simulation of Cone Crushers and High Pressure Grinding Rolls

   Författare :Johannes Quist; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Discrete Element Method; Modelling; HPGR; Comminution; DEM; Simulation; Crushing; Minerals Processing; Cone Crusher;

   Sammanfattning : The comminution of rock and ore materials consumes ~1.5-1.8 % of the total energy production in mining intensive countries (Tromans, 2008). Several research findings show that there are ways of utilizing compressive breakage modes that are more energy efficient compared to conventional grinding circuits based on large inefficient tumbling mills. LÄS MER

3. 12. Hole deviations in percussion drilling and control measures : theoretical and field studies

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

   Sammanfattning : In this thesis, we study the problem of hole deviations in percussive drilling and present a solution to minimize the deviations. Field tests are performed to study the interactive behaviour of drilling parameters. LÄS MER

4. 13. Pure shear fracture of brittle rock : a theoretical and laboratory study

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

   Sammanfattning : This doctoral thesis deals with determination of Mode II fracture toughness, KIIc, for rock. Three types of specimens, antisymmetric four-point bending, direct shearing and compression-shear specimens, are experimentally and numerically investigated. LÄS MER

5. 14. Freezing Temperature Flows in Railway Tunnels and its Consequence on the Rock Supporting Structure, the Rock and the Reinforcing Elements

   Författare :Anna Andrén; Lars-Olof Dahlström; Erling Nordlund; Lars O Ericsson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tunnel; frost penetration; ice formation; freeze-thaw test; frost shattering; temperature measurement; maintenance; degradation of rock and shotcrete; cold climate; Tunnel; köldinträngning; isbildning; frystester; frostsprängning; temperaturmätning; underhåll; nedbrytning av berg och sprutbetong; kallt klimat; Mining and Rock Engineering; Gruv- och berganläggningsteknik;

   Sammanfattning : Water in the surrounding rock mass flows into the tunnel via naturally occurring joints and via cracks caused by the blasting used to excavate the tunnel. The most common method in Sweden to reduce or prevent leakage problems are first and foremost the use of grouting. LÄS MER

7. 15. REAL TIME OPTIMIZATION OF ROCK CRUSHERS

   Författare :Erik Hulthén; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crushing plant; cone crusher; real time optimization; rock crusher;

   Sammanfattning : Cone crushers are used in the mineral, mining, and aggregate industry for fragmentation of rock materials. Cone crusher control systems are widely used for wear compensation and machine protection. These systems ordinarily focus on the crusher and not the crushed products. LÄS MER