Hot lime soda process is preferred over cold lime soda process due to following reasons like-

1- Hot lime soda process is carried out at high temperature (95-100°C) ,whereas cold lime soda process is carried out at room temperature (25-30°C).

2- Hot lime soda is a rapid process, but cold lime soda is slow process.

3-No coagulant is required here, in cold lime soda process coagulant is necessary.

4-In hot lime soda process filtration is easy as viscosity of water is low, but in cold process filtration is not easy.

5-Residual hardness is 15—30 ppm in hot lime soda process, whereas Residual hardness is 60 ppm in cold lime soda process.

6-. Dissolved gases are removed in hot lime soda process and it has high softening capacity, as compared to cold lime soda process.