The firm was also in talks with potential new strategic partners from the United States, South America and Europe to help cut costs, a senior executive said.
"We resumed operations in early November," executive director Wanlop Kunanukornkun told Reuters. "It will take two weeks for heating up before we can start feeding concentrate to the machine on November twelfth and thirteenth."
The shutdown in late July, due to equipment failure and misoperation as well as an earlier one which halted operations for most of March, meant production of around 80,000 tonnes this year, Wanlop said.
Thai Copper had planned to produce 120,000 tonnes in 2005.
The firm had cut its production target for next year to 135,000 tonnes from 165,000 tonnes but still expected output of 165,000 tonnes in 2007, Wanlop said.
"We still maintain our target for 2008 at full capacity of 180,000 tonnes."
The firm had been negotiating with the potential strategic partners, which he declined to name, to increase working capital, Wanlop said.
"We have been negotiating with three or four companies for six months now. It has been going well," he said.
"The price of copper is now very high, so if we have more strategic partners it means we will borrow less and that is good for the firm because the debt burden will come down as interest ratea are on an upward trend."
The firm imports copper concentrate, its main raw material and uses about 30,000 tonnes a month.
The current world price was about $4,000 a tonne this week, up from $3,600 a tonne three months ago.
The firm was established in 1994 but was forced to halt construction of its plant when it was 70 percent completed because it ran out of money during the 1997/98 Asian economic crisis.
Construction resumed in late 2002 after the firm sold stakes to strategic partners and restructured its debts.
Its main shareholders include Thai Asset Management Corp, Thailand's debt restructuring body, packaging firm Thai Film Industries PCL. and Norwegian group Aker Kvaerner ASA.