Log normal size distribution

Question 1

What size distributions are approximated by the log normal distribution?

Answer 1

~ spray dried granulates
~ fine grained milled powders
~ calcined aggregate

Question 2

What is the equation for a normal (Gaussian) distribution of the logarithms of particle sizes?

Answer 2

~ z = lnd
~ z’ = mean of log particle sizes
~ f(z) = 1/(sqrt(2pi) σ) * exp[(-(z-z’)^2/(2*σ)]

Question 3

What is σ?

Answer 3

~ geometric standard deviation or distribution speard parameter

~ σ = d84.13/d50

Question 4

What effects particle size distributions?

Answer 4

~ particle size distributions are significantly different when expressed based on particle diameter or particle volume

Question 5

What distributions are the same?

Answer 5

~ mass distributions are the same as volume distributions for SINGLE PHASE PARTICLES