A leaf filter of $0\mathrm{.}2m^2$ area operates at constant pressure drop of $500k\frac{N}{m^2}$ and produces

the following results during a test on filtration of flotation slurry:

$1\mathrm{.}1$ Determine the time needed to collect $2\mathrm{.}5m^3$ of filtrate during filtration of the same slurry

at a constant pressure drop of $400k\frac{N}{m^2}$ on a similar full$-$scale filter with an area of $4m^2?$

$1\mathrm{.}2$ Calculate the rate of passage of filtrate at the end of the filtration in $(1\mathrm{.}1)$

$1\mathrm{.}3$ How much time is required to wash the resulting filter cake with $1m3$ of water at a constant

pressure drop of $300k\frac{N}{m^2}.$

Coal, anthracite has the following size distribution:

If the total material is to be transported hydraulically using water $(10oC)$ through a $0\mathrm{.}3m$

horizontal pipe to a distance of $15km,$ in the form of a homogeneous slurry containing $20\%$

by volume of solids.

Estimate the minimum conveying velocity that is to be maintained.

Note: $SG$ of coal $=1\mathrm{.}5$

Quartz is fed at a rate of $25000kg/$hour to a ball mill that is operating in closed circuit with

a hydraulic classifier. The screen analyses of known streams are given below. The mill is

being operated with a recycle of $75000k\frac{g}{h}r.$ If the total power supplied to drive the mill

is $75kW.$

Determine the energy efficiency of the mill $($The particles are spherical $-=n=1)$

$3\mathrm{.}1$ From Rittinger's law

$3\mathrm{.}2$ From Bond's law