China's production of most base metals rose in August, reversing declines in the previous month, with primary aluminium hitting an all-time monthly high, official data showed on Tuesday, as smelters expect demand to improve in the next 3 or 4 months.

Metal demand in China, the world's top consumer and producer of copper, aluminium, lead, zinc, nickel and tin, has fallen this year after economic activity slowed in global markets.

Chinese smelters are hoping demand will rise in the fourth quarter, usually the peak consuming season, and will benefit from Beijing's increasing investment in infrastructure to boost an economy growing at its slowest pace in three years.

Production of refined copper rose 5.8 percent from the previous month to 511,000 tonnes in August, the second-highest level this year, but was still down 3.4 percent from a year ago.

"The rise in August reflected the fact that base metals smelters have prepared for better demand in September or October," said Yang Xiaoguang, an analyst at Jinrui Futures, a subsidiary of top copper producer Jiangxi Copper Corporation. Yang said he expected production of most base metals to extend this month's gains.

"Investment in the power sector should be higher in the second half than the first half," Yang said. "The National Development and Reform Commission (NDRC) already approved a lot of infrastructure projects in recent weeks, boosting the demand expectations."

China has given the green light to 60 infrastructure projects worth more than $150 billion, fuelling investor hopes the world's growth engine may get a lift in the fourth quarter of the year and beyond. A new 200,000 tonne-a-year copper smelter controlled by Zijin Mining also reached full production in August.

ALUMINIUM: Production of primary aluminium rose 4.7 percent from the previous month to a record 1.75 million tonnes in August. The output increased 12.7 percent from a year earlier.

Some factories that used primary aluminium to make semi-finished products such as profiles have been receiving more orders this month after a fall in orders in July and August, Yang said.

Primary aluminium smelters have continued to open new facilities in the second half after slowing construction in the first half due to weak demand and low prices, industry sources said.

NICKEL, LEAD, ZINC, TIN: Nickel production jumped 20.7 percent to 24,543 tonnes in August, recovering strongly from a fall of 14 percent in July.

"Demand in September should be better than August," said a sales manager at a nickel producer. "Some stainless steel mills started making enquiries to buy nickel last Friday and yesterday after the NDRC approved many projects."

Nickel production may rise further this month as producers restart idle capacity, the manager estimated. Refined lead production rose 8.8 percent from the previous month to 457,000 tonnes in August, the second-highest after an all-time record of 459,000 tonnes in June. Production of refined tin increased 4.8 percent from July to 12,989 tonnes in August, the second-highest this year.

Chinese solder makers are likely to increase refined tin purchases by the end of the year as they build inventories in anticipation of economic stimulus measures, and a spike in demand for their product, in 2013. Refined zinc increased 8.5 percent to 397,000 tonnes in August after output dived to a 29-month low in July.