MELBOURNE, Jan 29 (Reuters) - Australia's resources minister has begun a week long trip to South Korea and Japan to discuss gas exports and critical minerals opportunities, as its government on Monday released a "prospectus" of 52 investment ready critical minerals projects.

The resources-rich nation is seeking investment from allies in projects to develop minerals critical to green energy and at risk of supply chain disruption, spanning rare earths processing to various cobalt and nickel producing mines and plants.

"Australia's critical minerals are key to the world's energy transformation," said Minister Madeleine King in a statement.

"But we need to attract investment to get these minerals out of the ground, to process them here, to build the batteries, wind turbines and solar panels required make the switch to a lower carbon economy," she said.

King will be meeting Japan's trade minister Ken Saito, and South Korean trade and energy minister Duk-geun Ahn, she said in a statement.

The minister is also expected to engage her counterparts on natural gas as Australia develops its future gas policy, given both nations are large customers of the major exporter.

The push for investment comes amid a global downturn in prices for electric vehicle battery materials lithium and nickel, which have been hit by slower-than-expected electric vehicle uptake. For nickel, a flood of Indonesian supply has also hit prices. Already this year, a string of Australian nickel projects have been iced, including part of BHP's operations in the state of Western Australia. More are expected as miners report production this week.

King spent last week meeting industry leaders at several round tables in the country's resources heartland of Western Australia state amid announcements of closures and job cuts.

She pledged support for the sector and said she was determined to ensure Australian miners could compete with cheaper but lower grade minerals produced in less environmentally friendly ways overseas.

Last week, an Australian mining association said it had called for a 10% production tax credit, deferral of royalties and funding for shared infrastructure, among other measures at its meetings with the senior ministers. (Reporting by Melanie Burton; Editing by Christopher Cushing)