Efficient fiberline and recovery boiler start-ups at Sun Paper’s Yandian Mill highlight strong cooperation with Valmet

In August 2026, Shandong Sun Paper reached an important milestone with the start‑up of a new chemical pulping fiberline and recovery boiler at its Yandian Mill. Besides strengthening Sun Paper’s integrated pulp‑and‑paper operations and enhancing the quality and competitiveness of their high‑grade paper products, these projects stand as benchmarks of strategic cooperation between Sun Paper and Valmet.

Significant capacity increase

The new fiberline with a designed annual capacity of 600,000 tons is a major capacity addition for Sun Paper. Valmet’s delivery included a cooking plant, and a fiberline including washing, screening, oxygen delignification and bleaching, featuring advanced process technologies for high efficiency in energy and raw material use.  The delivery also included several Valmet analyzers and measuring devices for best possible control of the fiberline. The fiberline is press-based and ensures excellent product quality, minimal wastewater discharge, and strong environmental performance.

“I sincerely appreciate the dedication of both teams. Valmet’s proven pulping technology and reliable domestically manufactured equipment have supported efficient delivery and stable operation. We look forward to continuing our cooperation toward efficient, low‑carbon and intelligent production,” says Liang Hongjin, Project Director of the Yandian Pulp Line of Shandong Sun Paper.

The boiler maximizes energy recovery and minimizes emissions

The start-up of the new recovery boiler combustion section, including black liquor spraying and ignition, completed the successful commissioning of the Yandian Pulp Mill’s new production line. The solution ensures long‑term stable operation, lowers production costs, supports closed‑loop circular economy production, and advances green and sustainable development.

Valmet’s delivery included the recovery boiler and a crystallization chloride‑potassium removal system. This high‑performance boiler is designed for long‑cycle operation with extended service life and cleaning intervals. Its daily processing capacity of 3,500 tons of solids enhances the mill’s self-sufficiency in renewable electricity. The recovery boiler was equipped with a Valmet Smelt Spout Robot for automated smelt spout cleaning, further improving workplace safety. It was the first Smelt Spout Robot delivery to China.

“We are delighted with the smooth commissioning of the new recovery boiler. The new boiler together with the crystallization chloride‑potassium removal system meet Shandong Province’s stringent emission standards and enhance the projects' renewable power self-sufficiency,” says Fei Da, Project Director, Yandian Recovery Boiler Project, Shandong Sun Paper.

Jiang Shuaifeng, Recovery boiler Project Manager, Pulp, Energy and Circular Solutions Business at Valmet appreciates Sun Paper’s full support and efficient collaboration during the project.

“Despite some challenges during implementation, Valmet’s proven technologies, professional team and industry expertise – together with Sun Paper’s full trust and close coordination – enabled both sides to overcome difficulties, advance the projects, and achieve the start-up target of the alkali recovery,” he says.

Group photo of the startup team for Sun Paper & Valmet Recovery Boiler Project.

Results that speak for themselves

With the new fiberline and recovery boiler in operation, Sun Paper strengthens its position as one of China’s leading producers of high‑quality pulp and paper. The mill’s efficient start‑ups and stable performance demonstrate Valmet’s ability to deliver complete solutions combining advanced technology, safety, and environmental responsibility.

The full-line commissioning took 22 hours – from the first wood chip feeding to bleached pulp at the wet pulp warehouse – 30 minutes faster than the previous 22.5-hour record at Sun Paper’s Nanning mill, setting a new benchmark for starting up chemical pulping fiberlines.

The recovery boiler commissioning was equally record-setting: from the hydrostatic test to black‑liquor combustion, the entire cycle lasted only fifty days, with the combustion load of the alkali furnace reaching 90 percent on day one.

"Thanks to the seamless coordination and rapid response of both teams, Valmet efficiently completed scheme evaluation, design optimization and delivery adjustments, swiftly resolved on‑site issues, upheld the project schedule, and achieved smooth one‑time commissioning,” says Jing Zhenshan, Deputy Production Director of the Yandian Pulp Line.