Chemical Mass Balances

A short introduction to mass balances:

The basis of mass or material balances reside on the law of conservation of mass, according to which mass can not be created or destroyed.

The general formula used in calculations is the following: accumulation = input - output + generation - consumption

To start with, here is a very simple example:

Suppose a slurry containing 50% water and 50% solids are fed into a tank at 100kg/minute. A conveyer belt removes 45kg solids and 5kg water per minute. What mass of solids and water will leave the tank through the outlet as part of the clarified water if no accumulation occurs?

Answer: 5kg-Solids and 45kg-Water

No accumulation, generation or consumption occurs...thus, INPUT = OUTPUT
In one minute, 50kg solids ENTERS the tank, meaning that 50kg should LEAVE the system.
50kg - 45kg removed by conveyer belt = 5kg solids.
The same principle applies to the water.