Metso Anti-Blinding Screen Media reduced the product size by 5 mm for Shenchuan Mining

From shutting down once every hour to clean blinded screen apertures to achieving 0% screen blinding rate and reducing screened product size by 5mm, Shangri-La Shenchuan Mining Company has realized both production increases and cost reductions. The secret lies in their adoption of Metso Trellex® LS screen media.

Shangri-La Shenchuan Mining Company (hereinafter referred to as "Shenchuan Mining") is located on the Hongshan copper ore belt at an altitude of 4,200 meters in Diqing Tibetan Autonomous Prefecture, Yunnan Province. Since 1997, the company has completed four expansion projects. Through advanced equipment and scientific management, Shenchuan Mining has developed from a small operation with daily mining and processing capacity of 200 tons into a modern, large-scale provincial key mining enterprise with daily capacity exceeding 3,000 tons.

In 2009, Shenchuan Mining established a crushing plant with annual processing capacity of 1.5 million tons, adopting a three-stage closed-circuit process: primary crushing with a Metso Nordberg C100 jaw crusher, secondary and tertiary crushing with Metso Nordberg HP4 cone crushers, and screening with two domestic 2461 triple-deck circular vibrating screens.

A high-performance crushing-grinding process requires coordinated operation of all stages — any weak link will affect final production results. For Shenchuan Mining, as crushing and grinding processes were optimized, screening had become the bottleneck limiting overall production efficiency.

According to site personnel, screen blinding and material adhesion were extremely severe. To maintain normal crusher feed, workers had to shut down equipment every hour to enter the vibrating screen and manually remove stuck material with hammers. This not only disrupted production but also increased labor intensity and safety risks.

Moreover, the original screen design produced 10mm undersize material. Due to ineffective screening of properly-sized product, severe blinding and high circulating loads prevented the crushing system from meeting grinding circuit demands. Shenchuan Mining temporarily addressed this by enlarging apertures to 15mm, which improved mill feed volume but reduced grinding efficiency due to coarser feed size, ultimately increasing production costs.

Faced with hourly shutdowns, production workers were exhausted. Confronted with high production costs and underperforming capacity, management considered replacing the entire screens with imported equipment to solve this bottleneck. After Metso's site inspection, engineers identified the screen media — not the vibrating screens themselves — as the root cause, meaning complete screen replacement was unnecessary. This surprised Shenchuan Mining, as it promised significant cost savings.

On June 1, 2017, Shenchuan Mining held initial technical discussions with Metso. From technical exchange and site measurement to type selection and solution clarification, both parties quickly signed a purchase contract. "Metso helped us understand that screen blinding was the fundamental issue. Solving it for less than 10% of new screen costs was worth trying," said Danzeng Zhala, Chairman of Shenchuan Mining.

With Metso's support, Shenchuan Mining replaced all three decks of polyurethane screen media on the #2 screening vibrating screen with Metso Trellex® LS media, including lower deck 10×25mm apertures to meet designed product size requirements.

The screens immediately demonstrated outstanding performance after commissioning. Shenchuan Mining inspected screening results after 37 days of stable operation and media wear after 180 days.

Both inspections confirmed near 0% blinding rate with no material adhesion after switching to Metso media. The improved screening efficiency on just the #2 screen significantly reduced circulating loads and enhanced crushing efficiency. Moreover, product size returned to 10mm, improving mill feed volume and size distribution. The first set of Metso screen media has now operated stably for 390 days and remains serviceable.

"We no longer need hourly shutdowns!" said Arong Yixi, Concentrator Manager. "Metso's modular media design allows replacing individual panels in just 3 minutes, greatly reducing labor intensity and improving equipment efficiency. Overall liner consumption, power usage and grinding costs have decreased significantly."

"I'm extremely satisfied with this screen media modification. With just panel replacements solving our bottleneck, we've achieved major production and efficiency improvements, creating substantial economic benefits," commented Chairman Danzeng.

Today, the #1 vibrating screen has also been retrofitted, meaning all Shenchuan Mining screens now use Metso screen media. Ongoing monitoring and optimization continue.

Note: Metso Outotec was officially established on July 1, 2020. This article was prepared prior to that date under the former company name.