China's production of refined copper inched down 1.6 percent on-month in April after maintenance cut production at two smelters and insufficient supply of scrap raw material drove down smaller plants' output.
China, the world's top producer and consumer of refined copper, produced 584,277 tonne of metal in April versus 594,075 tonnes in March, data from the National Bureau of Statistics showed on Friday.
The April production was lower than what was expected by state-backed research firm Beijing Antaike Information Development, the firm's senior analyst Yang Changhua said. "I was surprised by the lower monthly official figure," Yang said, citing data collected by the firm.
He said that the firm had estimated the output should have risen from March. Tongling Nonferrous Metals closed 400,000 tonnes of smelter capacity for maintenance, a company spokesman said last month.
Production of refined copper from Jinchuan Group has fallen after one of two oxygen supply systems unexpectedly broke down in March.
The downed system is expected to be fixed by the end of June, a company source said.
Some refined copper producers faced insufficient supply of scrap raw material after weak prices and tight credit cut importers' spot buying last month and restricted selling of their stocks, industry sources said.
The April output was up 5.2 percent from a year earlier.
In the first four months of the year, refined copper production rose 6.4 percent on the year to 2.24 million tonnes, the data showed.
China's production of primary aluminium also fell 4.5 percent month-on-month to 1.9 million tonnes in April, the data showed.
Low prices and tighter environmental requirements in China forced some old, high-cost aluminium smelter capacity to temporarily close or cut production, industry sources said.
Spot prices in China reached 5-year lows in March.
The price has rebounded since then by more than 5 percent. April aluminium output was up 8.9 percent from a year ago.
Low prices also prompted smelters to slow production of refined lead used in lead-acid batteries for cars and electric bicycles.
The output fell 14.6 percent from the previous month to 324,181 tonnes in April.
Production of refined zinc, refined nickel and refined tin rose.
Zinc output stood at 455,509 tonnes in April, up 3.7 percent from March.
Nickel increased to 28,830 tonnes in April, up 0.7 percent on-month.
Tin rose 2.4 percent month-on-month to 15,325 tonnes.