The state government of Queensland in Australia on Tuesday has given a conditional stamp of approval to the $6.4 billion joint project of India's GVK Power & Infrastructure and Hancock Coal owned by the world's richest woman, Australian mining billionaire Gina Rinehart.

The green light was for the development of the Alpha Coal Project in Queensland state which is expected to generate around 30 million metric tonnes of thermal coal annually over its 30-year mine life.

Hancock Coal, owned 79 per cent by GVK Power & Infrastructure and 21 per cent by Rineheart, will operate the Alpha Coal Project.

However, the coal project still needs to secure environmental go-signal from the federal government in Canberra as well as a mining lease from the state before proceeding with development plans and construction which is expected to occur between 2013 and 2016.

"There'll be an estimated Aus$11 billion boost to the economy during the mine's three year construction phase, of which 80 per cent will be retained in Queensland," Jeff Seeney, Queensland Minister for State Development, Infrastructure and Planning, said in a statement to the local parliament.

"Once operational, Australia can expect an Aus$80 billion dollar rise in exports over the life of the mine, while Queensland's economy should see an economic boost of Aus$1 billion per year from this mine alone," he added.

"The state approval paves the way for us to complete financing and secure final mining approvals for the Alpha project in the second half of 2012," GVK Reddy, GVK Chairman, said in Reuters News.

The conditional approval laid down 128 provisions for handling environmental impacts from building the 30 million tonne-a-year thermal coal mine along with the 495 kilometer rail line from the mine to the Abbot Point port

"It's another step towards getting a mining lease and final approvals," Chris Bombolas, spokesman for Hancock Coal, was quoted as saying by The Sydney Morning Herald.

At the same time, the proponents of the Alpha Coal Project continued to affirm it will source foreign workers to support the development of the mine.

Although many Australians want to be part of the country's mining work boom, they are unfortunately turned down because of lack of skills.

GV Sanjay Reddy, vice-chairman of GVK Power & Infrastructure, said employing Australian workers are a priority, but foreign workers however were good insurance, The Sydney Morning Herald reported.

''Our priority is offering locals and other Australians the opportunity to work on these projects,'' Reddy said in a statement.

''Last year, the federal government invited us and other major companies to look at EMAs (Enterprise Migration Agreements), but we need to review them with contractors and will consider the issue over the next few months. We have not applied for EMAs but with large numbers required for the construction phase, we see them as a good insurance.''

Some 3,600 jobs are expected to be made available during the construction of the Alpha Coal Project and nearly 1,000 once it goes online.