United States – Phasing out a major cost item through the smart reuse of waterEvery year, the South Portland terminal of the North America, Maine facility cleans around 3,200 rail tank cars that supply paper-making customers with Capim clays. The cleaning process used to involve eight or so cars being shipped each month to Middle Georgia Kaolin, where the low-solids waste water they contained was placed in an impound basin. Since 2005, efforts have been made to reduce the substantial transportation and disposal costs entailed. The water recovery project implemented in 2009 has eliminated them completely.
Now the plant reuse the process water for continuous cleaning of railcars until the solids reach a pre-determined level. Once that level is achieved, the water is screened, quality-tested, treated and added to finished product storage tanks.
The transferred water has to be managed so that the clays remain within customer specification ranges. It’s also critical to carry out microbiological controls on the wash water. As well as cost savings, the new process generates thousands of tons of salable clay every year.