9.8 Mt/a gneiss line in Tongcheng passes its trial run

Lines capable of nearly ten million tonnes a year are rare enough to count on one hand. One of them is in Tongcheng, Anhui: 3.23 billion RMB invested, 9.8 million tonnes a year, and the rock is gneiss — not an easy material.

The mining right was won by a state-owned enterprise in Anqing in 2022: 250 million tonnes of recoverable reserve, a 27-year mine life, built by China Railway 23rd Bureau, and listed as a Class A provincial energy project.

On a project of that size and that duration, one wrong choice of key equipment becomes a long, expensive problem.

Shuangjin's process team made more than twenty site visits before the circuit was settled. They worked through the terrain drop, bunker layout and crushing stages — and, more importantly, the specific trouble with gneiss: high flakiness content and poor control of particle shape.

The agreed answer is a closed four-stage circuit: primary, secondary, tertiary and shaping.

Primary: two SJ.V.1300 European-type jaw crushers. Secondary: two SK.50.20 single-cylinder hydraulic gyratory crushers. Tertiary: four SK.D.1800 multi-cylinder hydraulic cone crushers — the machines the industry calls P8. Shaping: four SJ.L.630 vertical shaft impact crushers. Screening: ten SJ.3.Y.K.36.80 circular vibrating screens, plus feeders and auxiliary screens, all on closed circuit.

Eight hours of continuous running with material: output, vibration and product gradation all held where they should be.

Shuangjin's service engineers stay on site through commissioning. Thirty-nine years in crushing and screening is what stands behind the survey, the process design, the equipment supply and the installation.