Tokuyama runs seven mills above 90% automatic operation at its Nanyo cement plant after extending ABB's optimiser across the grinding circuit

Nanyo, Japan. Tokuyama Corporation has extended ABB's Expert Optimizer advanced process control system to seven mills at its Nanyo plant and reports an automatic operation rate above 90% across the grinding circuit, according to an account published by World Cement on 2 September.

The deployment began with a single finish mill in 2024. It has since been commissioned on six more: four cement ball mills and two vertical mills, one for pre-grinding and one for slag.

What was measured

• Automatic operation rate: above 90% on the finish mills.
• Grinding throughput: up 3%.
• Specific power consumption: down 3%.
• Kiln: specific heat consumption down 3%, and manual operator actions down 70%, following an earlier optimisation reported in 2022.

The plant reports that the gains were achieved while maintaining stable operations, which in a grinding circuit is the harder half of the problem: an optimiser that raises throughput by destabilising the mill does not survive contact with a production schedule.

"We decided to extend the use of the solution to the entire cement mill process." — Junya Doi, Engineering Section, Cement Manufacturing Department, Tokuyama

The system combines model predictive control with AI, and is the same product line ABB has been placing in cement and minerals plants for several years. Hiromichi Yoda, who runs ABB's Process Industries division in Japan, framed the result as a step toward autonomous operation of the plant rather than a one-off efficiency project.

Why it matters

Cement is among the most energy-intensive industries in the world, and grinding is where a large share of a plant's electricity goes. A 3% cut in specific power consumption sounds modest until it is multiplied across seven mills running continuously. The 70% reduction in kiln operator actions is the more telling number: it describes a change in how the control room actually works, not just a line on an energy bill.

Figures are those reported by Tokuyama and ABB. They have not been independently verified.