How is the concentration of weak black liquor described before it undergoes further processing?

The concentration of weak black liquor before it undergoes further processing is typically described as containing 13-17% concentrated solids. This range indicates that while the liquid is somewhat concentrated, it still has a significant amount of water, which is characteristic of weak black liquor. This concentration is important because it affects the efficiency of subsequent processing steps, such as evaporation and recovery of chemicals. Understanding this concentration range helps operators manage the processing conditions to optimize the recovery of energy and chemicals from the black liquor effectively.