Excavation Engineering Theory of Fragmentation Quiz
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Questions and Answers

What is the primary interest in studying the breakage behavior of rock in the mineral industry?

To produce a certain, desired fragmentation result

What is the goal for Quarries in terms of rock fragmentation?

To produce aggregates

What is the goal for Mines regarding rock fragmentation?

To extract ores

What is the significance of understanding rock specific fragmentation behavior?

<p>To predict and evaluate the performance of excavation machines</p> Signup and view all the answers

Is the characteristic of a fragmentation result material specific?

<p>Yes</p> Signup and view all the answers

Can the characteristic of rock fragmentation be described?

<p>Yes</p> Signup and view all the answers

What are the operational parameters that control the fragmentation result?

<p>Screen size and passing percentage</p> Signup and view all the answers

What is the range of uniformity indices for broken material in the theoretical distribution?

<p>Between 0.5 and 1.5</p> Signup and view all the answers

What is the first derivation of the particle size distribution curve calculated for each class?

<p>Local slope</p> Signup and view all the answers

What is the specific energy required for crushing Amphibolite in the lab crusher?

<p>[kJ/t]</p> Signup and view all the answers

What type of explosives are used in the small scale blast fragmentation tests?

<p>Nitropenta</p> Signup and view all the answers

What is the size range of samples used in VOD measurements during small scale blast tests?

<p>100 – 300 mm in diameter</p> Signup and view all the answers

What is the specific energy input range observed in the lab scale blast tests?

<p>0.01 - 100 kJ/t</p> Signup and view all the answers

What material shows a specific breakage behavior in the observation of the fragmentation process?

<p>Amphibolite</p> Signup and view all the answers

What is the key finding regarding the characteristics of the fragmentation curves when comparing blast and mechanical fragmentation?

<p>The characteristics in the fines and middle size range do not change significantly.</p> Signup and view all the answers

What type of influence does the type of fragmentation process have on the distribution characteristics in the fines range?

<p>Little influence</p> Signup and view all the answers

What is the local slope observed in the model scale for the fragmentation results?

<p>2.0</p> Signup and view all the answers

What screen size shows a minimum local slope around x = 0.5 mm in the full-scale fragmentation results?

<p>10 mm</p> Signup and view all the answers

What does NBC stand for in the context of particle size distribution?

<p>Natural Breakage Characteristic</p> Signup and view all the answers

How is the particle size distribution converted into a particle surface value?

<p>Measurements (&lt; 100 microns) and calculation</p> Signup and view all the answers

What is the significance of the Local Slope (n) value in the fragmentation curves?

<p>Position of n minimum same for lab &amp; full scale fragmentation curves</p> Signup and view all the answers

What is the purpose of characterizing the fragmentation result based on Specific Surface [cm²/g]?

<p>Characterization of a fragmentation result</p> Signup and view all the answers

What does the Cumulative Net Energy Consumption [J/g] measure in the context of fragmentation?

<p>Fragmentation technical Fragmentation</p> Signup and view all the answers

Which type of material exhibits a Specific Surface of 900 cm²/g in the characterization of fragmentation?

<p>Amphibolite</p> Signup and view all the answers

What is the main purpose of the Rittinger coefficient for various rock types?

<p>Describing the energy required to grind rocks</p> Signup and view all the answers

What does the Energy Register function from comminution & blasting tests describe?

<p>The specific surface versus specific energy input relationship</p> Signup and view all the answers

How is the NBC (Natural Breakage Characteristic) of a rock defined?

<p>By the characteristic of the distribution of the size of particles formed by a fragmentation process</p> Signup and view all the answers

What does the Specific Surface represent in the context of rock fragmentation?

<p>The surface area per unit mass of the rock</p> Signup and view all the answers

How is the Powder Factor related to the specific energy consumption in blasting?

<p>Powder Factor is the ratio of explosive energy to the rock mass, affecting the energy consumption</p> Signup and view all the answers

What is the significance of the Energy Register function for lab and full-scale blast tests?

<p>It helps in understanding the relationship between specific surface and specific energy consumption</p> Signup and view all the answers

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