Potlatch Corporation Starts Up Pulping Technology from Valmet

Published Dec 28, 1999 00.00.00 +2 GMT

Potlatch Corporation, USA, has successfully completed and started the modernization at its mill in Cloquet, Minnesota. The new investment is a part of the Potlatch Corporation’s strategy to achieve financial objectives including expanding their market pulp business, and to meet or exceed environmental requirements. The new line is designed for a production rate of 1,278 tons per day of mixed hardwood, or 1,160 tons per day softwood of pine in campaigns.

Valmet Chemical Pulping (former Sunds Defibrator) was awarded the order for upgrading and modernizing the fiber line at the Cloquet mill in early 1998. The company supplied an expansion to the existing wood-handling and SuperBatchTM cooking systems, an OxyTracTM oxygen-delignification process, and an ECF three-stage bleaching process.

The wood-handling system is specially designed to maximize chip yield from wood, reducing fines and damaged fibers. The SuperBatch cooking expansion included four additional digesters, which doubled the present capacity. The fiber line technology chosen represents the most advanced technology for environmentally sound pulping. TwinRollTM presses are used for all stages of intermediate washing in the fiber line. The press-based process minimizes the amount of circulating liquors and effluent discharge due to its high operating consistency (outlet > 30%), and it enables a low building volume.

Valmet also provided DCS programming, extended process engineering services, as well as erection, commissioning and start-up assistance. The main process equipment was manufactured at Valmet’s production facilities in Finland and Sweden.

Valmet, the Fiber and Paper Technology business area within Metso, a world leading supplier of technologies, systems and equipment for the pulp, paper and panelboard industry was formed following the recent merger of Sunds Defibrator and Valmet Paper Machinery.

Metso Corporation was created through the merger of Valmet and Rauma on July 1, 1999 and comprises three business areas – Fiber and Paper Technology, Automation and Control Technology and Machinery. In 1998, the pro forma net sales of Metso amounted to EUR 3.7 billion (FIM 22 billion). The combined number of employees was approximately 23,000. Metso Corporation is listed on the Helsinki and New York Stock Exchanges.

For further information, please contact:

Lars Sjödin Vice President & General Manager Chemical Pulping Sundsvall, Sweden

Thore Englund Vice President Corporate Communications