Sep 16 2008
The China Aluminium Industry Stock Company (Guizhou, China) is using an Insitec on-line particle size analyzer from Malvern Instruments to produce better quality carbon at lower variable cost. The milled carbon is used to manufacture electrodes for aluminium smelting, and particle size directly influences electrode performance. Installation of the Insitec has led to automated control, optimized operation of the milling circuit and reduced variable costs.
The carbon is milled in a ball mill, a downstream classifier separating off the final product. Traditionally, particle size was measured by off-line sieve analysis which is both time-consuming and manually intensive. The on-line Insitec analyzes much more frequently and more rapidly, providing real-time data for control. These data are used to automatically vary classifier speed, maintaining product particle size in the specified range.
The Insitec proved to be easy to install, was rapidly commissioned, and has run reliably ever since. Improved control has led to a reduction in over-milling, reducing energy consumption and increasing throughput. Furthermore, because particle size is so closely controlled there have been improvements in product quality.
The Insitec is a laser diffraction-based particle size analyzer designed to operate 24 hours a day, 7 days a week with minimal manual intervention. It has no moving parts and accurately measures even concentrated streams. Suitable for particles in the size range 0.1 – 2000 microns it has a measurement frequency of 0.25 Hz (four measurements per second).