The Zijinshan Gold‑Copper Mine in Longyan has long struggled with the dual problem of disposing massive amounts of blasting slag, neutralised dreg and steel slag while keeping haul roads in good shape for the 100‑ton trucks that shuttle ore to processing plants.
Lead researcher Jia‑Ming Wen explained that the team combined 17 parts water‑quenched steel slag, 2 parts waste cement and 1 part lime slag into a binder that was mixed with equal parts blasting slag and neutralised dreg. The binder content was varied from 3% to 15% by dry weight; the 15% mix was chosen for field trials because it achieved the 3.0 MPa compressive strength benchmark for road bases.
Field tests ran on 30‑cm thick sections covering 2,500 m² on the 670‑ and 730‑metre levels of the waste dump. After 28 days of service, the 15% binder base bent only 2.6 mm under a 100‑ton truck load, a 97.19% reduction compared with plain blasting slag. The same mix also released cadmium, mercury and chromium at 0.007, 0.00003 and 0.02 mg L⁻¹, all below the national groundwater Class IV standard.
Beyond strength and safety, the new pavement cut cradle‑to‑gate CO₂ emissions from 13.4 kg m⁻² (fly‑ash) to 7.5 kg m⁻², a 53% reduction. Costs hovered around US$6.99 per m² for the 15% mix, only slightly higher than conventional cement‑stabilised roads. The research team anticipates a pilot rollout at other provinces later this year, with the Ministry of Industry and Information Technology set to review the technology for national deployment by Q4 2024.