Rusal started using machine hearing for the first time in alumina production
The mathematical algorithm analyzes the vibro-acoustic signals of the mills and thereby ensures optimal loading of the mills with bauxite ore, which reduces equipment wear and power consumption.
Photo: "Rusal Krasnoturinsk".
The technology for controlling the loading of mills using machine hearing was developed by the Rusal Engineering and Technology Center, and it was successfully tested on a small wet milling unit at the Rusal Krasnoturinsk alumina plant.
Rusal has created, tested and implemented a large number of technologies based on machine vision, the technology using machine hearing was developed by the company for the first time. Vibro-acoustic sensors are installed on the mill supports, the captured sounds undergo analog-to-digital conversion, then a mathematical algorithm determines the degree of ore loading of the mills by frequency and amplitude of vibrations and issues a task to the mill feeder. The algorithm is trained to identify the exact relationship between the sound characteristics and the degree of loading of the mills and not to react to extraneous noise.
Constant optimal loading of mills is important for energy saving, high-quality grinding and equipment safety. When ore is underloaded, electricity is wasted on the rotation of the mill, and grinding balls instead of ore beat against the inner lining of the mill, leading to mutual wear. An overloaded bauxite mill, on the contrary, produces poor-quality coarse grinding, which reduces the efficiency of the next technological process – leaching – and the commercial yield of alumina. Prolonged overloading can also lead to more frequent repairs of the mill.
The Engineering and Technological Directorate of Alumina Production has begun evaluating the possibility of implementing the technology at the Achinsk Alumina Combine (AGC). AGK is the only alumina plant in the world operating on a mixture of nepheline and limestone ores. Its grinding technology and mills generate vibro-acoustic signals different from bauxite mills, so the machine hearing system at the AGC will need individual tuning.