North stradbroke island

Mineral sand mining on North Stradbroke Island in Queensland is undertaken by Sibelco Australia, a subsidiary of the international Sibelco Group that was founded in Belgium in 1872. The mine is planned to expire in 2027 when 80 percent of the mine site will be taken over by the Queensland government for use as a national park.

The North Stradbroke Island sand mining operation has consisted of three separate mines; Yarraman, Enterprise and Vance. The Yarraman mine was closed in December 2014, with Enterprise and Vance due to close no later than 2025, when the licence to mine sand on the island expires. The Enterprise sand mine has sufficient resources to allow it to continue mining until 2035, if Sibelco applies for and is granted a renewal on their current lease, although this is doubtful considering public sentiment surrounding the issue.

Before mining activities take place on North Stradbroke Island the vegetation is removed and topsoil stripped for stockpiling to be resettled once mining of that specific area is complete. On some occasions the topsoil has gone directly to mined out areas for immediate rehabilitation purposes.

Two types of sand mining is used depending on the circumstances involved, these being:

1. Dredging. This involves a floating dredge situated on an artificial freshwater pond using a rotating cutter to loosen the underwater sand deposit. Once free, the sand is pumped to the floating concentrator at a speed of 3000 tonnes an hour.

2. Dry mining. This is the process undertaken to supply supplementary feed to the dredge. This is primarily used for the purposes of mining sand suitable for making glass. Dry mining units (DMU's), that compliment heavy mineral production, were introduced to the North Stradbroke Island operation in 2003.

Because North Stradbroke Island is so highly environmentally sensitive, Sibelco goes to great lengths to conduct detailed pre-mining surveys as well as monitoring the environment, including full consultation with the community and all relevant stakeholders. This is to ensure all endangered wildlife and plant species are always fully protected. If any species is located where the mine will be proceeding the company ensures re- establishment occurs after mining passes through and the area is rehabilitated. The company works close with members of the Island's indigenous Minjerribah Moorgumpin elders, in Council, to make certain the indigenous cultural heritage of the Island remains protected.

Sand and minerals recovered during the mineral sand mining operation on North Stradbroke Island pass through a trommel that separates, and rids itself, of rubbish and large rocks. A gravity separation process then takes place in the concentrator using gravity through a series of water fed spirals that remove the heavier minerals that contain ilmenite, zircon and rutile from the lighter sand. Because ilmenite contains iron it becomes separated from zircon and rutile through the use of wet high intensity magnetic separators. The clean sand is then pumped from the dredge where it is used to reform and reshape the sand dunes. Final separation of the minerals is carried out in a dry mill at Pinkenba at the mouth of the Brisbane River.

Mineral sands have been mined at North Stradbroke Island since 1966. Late in 2002 Sibelco Australia introduced the Yarraman Improvement Project that resulted in an improvement being obtained in the processing of sand containing higher amounts of clay and fines. The project involved certain modifications being made to the process, mechanically, as well as to control equipment, including an improved procedure that required following. This included better tails control through a rheology modifier