The Philippines' sulphuric acid exports fell by 34pc to 564,000t in 2018, reflecting production difficulties, customs data show.
India was the leading export market, receiving 221,000t, down by 25pc. But shipments to Thailand rose by 7pc to 120,000t. Deliveries to China fell by 95pc to just 10,000t.
Switzerland-headquartered Glencore, which runs the 1.1mn t/yr Pasar copper smelter, is the Philippines' only sulacid exporter. But the smelter struggled to maintain consistent production because of a failure at its acid plant at the start of the year.
Imports down, metal throughputs stable
The Philippines' imports fell by 4pc on year, according to analysis of trade partner data.
Export figures from key suppliers Japan, South Korea and China and smaller suppliers show 2018 imports hit 1.29mn t.
But government customs data puts the total at 920,000t, down by 27pc.
The Philippines' customs authorities tend to understate import figures, but export volumes mostly match with partner-country tallies.
Japanese customs data show its exports to the Philippines totalled 1.04mn t last year, up by 3pc. While South Korean data show shipments to the Philippines of 95,000t, up by 184pc on 2017.
The Philippines' imports of sulphuric acid are mainly used in nickel-cobalt high-pressure acid leach mining operations at Taganito and Coral Bay. Neither operation suffered any unplanned downtime last year.
