1.2 b.
From
To
0.00
2.00
2.52
3.18
4.00
5.04
6.35
8.00
10.10
12.70
2.00
2.52
3.18
4.00
5.04
6.35
8.00
10.10
12.70
16.00
Sum =
Assuming a Sphere,
Average
number(ni) nixi
nixi^2
nixi^3
(xi)
1.00
2738.00
2738.00
2738.00
2738.00
2.26
5108.00
11544.08
26089.62
58962.54
2.85
5396.00
15378.60
43829.01
124912.68
3.59
5510.00
19780.90
71013.43
254938.22
4.52
5109.00
23092.68 104378.91
471792.69
5.70
5151.00
29334.95 167062.51
951421.00
7.18
3869.00
27760.08 199178.54 1429106.01
9.05
1799.00
16280.95 147342.60 1333450.51
11.40
329.00
3750.60
42756.84
487427.98
14.35
24.00
344.40
4942.14
70919.71
61.89
35033.00 150005.23 809331.60 5185669.34
Calculating the dSn , dVn and dSvn .
Number Basis,
dSn =
DVn =
dSVn =
From
0.00
2.00
2.52
3.18
4.00
5.04
6.35
8.00
10.10
12.70
To
2.00
2.52
3.18
4.00
5.04
6.35
8.00
10.10
12.70
16.00
Average
number(ni) nixi^4
nixi^5
nixi^6
(xi)
1.00
2738.00
2738.00
2738.00
2738.00
2.26
5108.00
133255.35
301157.08
680615.01
2.85
5396.00
356001.13
1014603.23
2891619.21
3.59
5510.00
915228.20
3285669.24
11795552.57
4.52
5109.00
2132502.96
9638913.36
43567888.40
5.70
5151.00
5418342.62
30857461.23 175733241.68
7.18
3869.00
10253835.63
73571270.64 527873866.84
9.05
1799.00
12067727.09 109212930.18 988377018.13
11.40
329.00
5556678.93
63346139.76 722145993.27
14.35
24.00
1017697.82
14603963.78 209566880.19
37854007.73 305834846.50 2682635413.31
Derivation of the weight basis formula is included in the other page.
Weight Basis,
dSw =
DVw =
dSVw =
1.2.c
Showing that the size distribution follows the log-normal Distribution:
From(m)
0.00
2.00
2.52
3.18
4.00
5.04
6.35
8.00
10.10
12.70
To (m)
2.00
2.52
3.18
4.00
5.04
6.35
8.00
10.10
12.70
16.00
Average
1.00
2.26
2.85
3.59
4.52
5.70
7.18
9.05
11.40
14.35
Number
2738.00
5108.00
5396.00
5510.00
5109.00
5151.00
3869.00
1799.00
329.00
24.00
fn(x)
0.07815
0.14581
0.15403
0.15728
0.14583
0.14703
0.11044
0.05135
0.00939
0.00069
Cumul.Under
0.07815
0.22396
0.37799
0.53527
0.68110
0.82813
0.93857
0.98992
0.99931
1.00000
Cumul.Over
1.00
0.92
0.78
0.62
0.46
0.32
0.17
0.06
0.01
0.00
Particle Size (um)
Arithmetic Normal Dis
18.00
16.00
14.00
12.00
10.00
8.00
6.00
4.00
2.00
0.00
Series1
Cumulative Undersize
As the graph produced from the Logarithmic Normal Distribution is linear for Particle size vs
Cumulative undersize, the data given follows the log normal distribution.
Calculating the Geometric Mean using the graph from the previous page
D50 = 3.80
D16 = 2.25
D84 = 6.4
=
or, =
= 1.68
=
= 1.68
Therefore, = 1.68
And
Dgn = 3.80
Calculating
Dan, dSn , dVn and dSvn
(
( ( ))
( ( ))
( ( ))
( ( ))
1.4 a
Calculating the median, mode and mean of the mass distribution
From
To
0
1
3
5
7
9
11
13
frequency(ni) Average(xi)
1
3
5
7
9
11
13
0
sum =
0
5
8
12
8
6
4
0
43
0.5
2
4
6
8
10
12
6.5
Mass
fraction
fn(x)
cumulative
under
0
0.116279
0.186047
0.27907
0.186047
0.139535
0.093023
0
0
0.11627907
0.302325581
0.581395349
0.76744186
0.906976744
1
1
cumulative over
fn*xi
1
1
0.88372093
0.697674419
0.418604651
0.23255814
0.093023256
0
Mean =
0
0.232558
0.744186
1.674419
1.488372
1.395349
1.116279
0
6.651163
To calculate mode
0.3
mass fraction, fn
0.25
0.2
0.15
0.1
0.05
0
0
10
12
14
Size (um)
From the graph above, the highest mass fraction occurs when the size is 6
Cumulative
To calculate the median
1.2
1
0.8
0.6
0.4
0.2
0
Undersize
Oversize
0 1 2 3 4 5 6 7 8 9 10 11 12 13
Size(micron)
The above plot of cumulative mass fractions vs size gives a d50 = 6.5m
. So, the median is