diagram balance point Mill 2017 Mill 1973 Mill 2017 Mill 1973 Incoming flows Salt cake from ClO 2 plant 3 7 A Spent acid from tall oil plant 0 0 0 B Wood 0 0 0 C Recirculated filtrate from bleaching 0 0 0 0 D External fuel to lime kiln and recovery boiler 0 0 .