case study

Industry: Alumina Refinery

High Variability in Titration Measurement System

FOCUS: High variability in titration measurement system


The refinery was experiencing high variability in their titration measurement system. Titration measurement is the quantitative chemical analysis that is used to determine the unknown concentration of chemicals.  This was resulting in high variability in the process chemistry (A/C ratio =g/l Alumina /g/l Sodium Hydroxide).


An improvement team was assembled to analyze the problem and implement required improvements.  The team applied appropriate process analysis and statistical six sigma tools to reduce the variability of the measurement process. Several opportunities to improve quality and efficiency were implemented.
This resulted in the following improvements:
– The pooled standard deviation of the A/C Ratio for the four titration systems in use was
reduced by 69%.
– The variability of the individual components was reduced from 41% to 71%.
– Improved plant A/C Ratio control and reduced lost production due to not maintaining target
production Ratios.
– Reduced downstream problems caused by high A/C Ratios.


As a result of the process improvements, the company realized annualized ROI (Return On Investment) benefits of $180,000. Additionally, Indirect savings were also realized through increased productivity due to less maintenance problems caused by poor ratio control.

* Due to nondisclosure agreements, the organization referenced in this example cannot be disclosed.