HARARE, July 23 (Reuters) - Impala Platinum's IMPJ.J Zimbabwean business is considering reopening a mine mothballed in 1998, an official said on Wednesday, after platinum prices rallied to their highest level in more than a decade.

Australia-listed Zimplats ZIM.AX, 87% owned by Impala, took over the Hartley mine when it acquired assets previously owned by BHP in 2001.

The mine was put under care and maintenance after failing to meet key production targets, Impala board chairperson Thandi Orleyn said during the commissioning of a 35 megawatt solar plant at Zimplats on Wednesday.

"Zimplats is conducting studies and trials to develop a safe and efficient mechanised mining method for reopening the mine," Orleyn said, without giving further details on any time frame or possible capacity.

Platinum prices surged 36% in the second quarter, driven by a rise in Chinese imports and a drop in supply from major producer South Africa.

A two-year slump in prices has forced Impala and its peers to suspend projects and cut costs.

Last year, Impala postponed spending on some of its $1.8 billion capital projects at Zimplats, citing weak prices for the metals used to make catalysts that curb toxic emissions in vehicles.

The company has, however, now completed projects including the first phase of a 185 megawatt solar plant and an expanded smelter, which were officially commissioned on Wednesday.

Zimplats said it planned to complete the capital projects, including the rehabilitation of a base metal refinery, by 2031.

(Reporting by Chris Muronzi and Philemon Bulawayo; Editing by Nelson Banya and Alison Williams)

((Nelson.Banya@thomsonreuters.com;))