the effect of the particle size distribution on non-newtonian turbulent ...

Chapter 3 Experimental Work Page 3.22
3.6.2 Rock Flour
Rock Flour was obtained from Hippo Quarries from <strong>the</strong>ir quarry called Peninsula.
3.6.3 Sand
Sand was obtained from Consol in 2Skg bags called No. 2 Foundry Sand. The <strong>particle</strong> <strong>size</strong>
<strong>of</strong> <strong>the</strong> sand was between 7S and 3S0 /Lm.
3.7 ]',llXTURES
3.7.1 Mixture Kaolin Clay and Rock Flour
The rock flour was found to form a settling slurry when mixed with water. In order to
obtain a homogeneous slurry kaolin clay was used as a suspending agent for <strong>the</strong> rock flour.
Tests were <strong>the</strong>refore conducted to determine <strong>the</strong> amount <strong>of</strong> kaolin clay needed to suspend <strong>the</strong>
rock flour.
Twenty sample bottles each containing 200g <strong>of</strong> water were used for <strong>the</strong> tests. For Test A,
10 <strong>of</strong> <strong>the</strong> sample bottles contained rock flour at a relative density <strong>of</strong> 1,1 and for Test B, <strong>the</strong>
remaining ten sample bottles contained rockflour at a relative density <strong>of</strong> 1,2.
Kaolin clay was <strong>the</strong>n added to <strong>the</strong> sample bottles in Test A, starting at 5g <strong>of</strong> kaolin clay for
L1e first sample bottle and increasing in Sg amounts per sample bottle until <strong>the</strong> last sample
bottle contained SOg <strong>of</strong> kaolin clay. The rock flour and kaolin clay were <strong>the</strong>n thoroughly
mixed and allowed to stand. This procedure was repeated for Test B.
It Was found that in both Test A and Test B that 30g <strong>of</strong> kaolin clay was required to suspend
<strong>the</strong> rock flour and form a homogeneous slurry. At 25g <strong>of</strong> kaolin clay added, <strong>the</strong> mixture
formed a slow settling slurry and hence <strong>the</strong> critical point lay between <strong>the</strong>se two limits ie. 2Sg
and 30g <strong>of</strong> kaolin. It was <strong>the</strong>refore decided to use <strong>the</strong> concentration ratio <strong>of</strong> 30g <strong>of</strong> kaolin
clay per 200g water to suspend <strong>the</strong> rock flour for <strong>the</strong> tests in <strong>the</strong> pipelines or a kaolin
conCentration <strong>of</strong> at least Cv =S%.