Pluton Resources Limited (ASX:PLV) Dry Magnetic Separation Test Work to Commence on 3mm Grind Size

Melbourne, July 12, 2011 AEST (ABN Newswire) - Pluton Resources Limited (ASX:PLV) are pleased to advise that based on recent positive dry magnetic separation test work results from a sample of Wonganin Sandstone, further test work will be carried out at a coarse 3mm grind size on drill core composite samples taken from the Wonganin Sandstone and Yampi Member at the Hardstaff Peninsula.

The production of a +40% iron pre-concentrate at a 3mm grind size would offer significant capital and operating cost benefits as well as processing benefits.

HIGHLIGHTS

- Production of a dry pre-concentrate with final processing off-island was identified as the preferred model for development of Irvine Island in the Pre-Feasibility Study.

- Previous tests confirmed that a +40% iron pre-concentrate could be produced on Irvine Island at a grind size of 1 mm.

- Test work on a representative sample of Wonganin Sandstone (PLV_8) indicates the iron ore is amenable to upgrading to a +40% iron pre-concentrate at 2 mm or 3 mm grind sizes.

- The production of a +40% iron pre-concentrate at a 3mm grind size would offer significant capital and operating cost advantages as well as processing benefits.

- Based on the test result, 3mm bench scale dry magnetic separation tests will be carried out on composite drill core samples from the Wonganin Sandstone and Yampi Member at the Hardstaff Peninsula.

Metallurgical Test Work Objectives

Pluton's Pre-Feasibility Study selected the production of a dry pre-concentrate on Irvine Island with final third-party off-island processing to a high grade concentrate as the preferred case for development of the Irvine Island project. This was also considered to offer the best environmental solution at Irvine Island.

Previous dry magnetic separation test work conducted on both the Wonganin Sandstone and Yampi Member drill core samples from the Hardstaff Peninsula confirmed that a +40% iron pre-concentrate could be produced at a grind size of 1 mm.

A representative sample of the Wonganin Sandstone (PLV_8) was collected from metallurgical drill hole 10DDH039 located at the southern end of the Hardstaff Peninsula and submitted for dry magnetic separation test work. The aim of the test work was to determine if the sample could upgrade to a +40% pre-concentrate at a coarser grind size of 2mm and 3mm.

The results of the test work from sample PLV_8 have shown that the Wonganin Sandstone sample does upgrade to a +40% pre-concentrate at both a 2mm and 3mm grind size. Based on this positive result, Pluton will commence 3mm bench scale dry magnetic separation test work on both the Wonganin Sandstone and Yampi Member drill core composites samples at a range of iron grades.

The production of a +40% pre-concentrate at a coarser grind size of 3mm would offer significant advantages for capital and operating costs as well as processing benefits.

This announcement details the procedure and test work results for dry magnetic separation of metallurgical sample PLV_8 from the Wonganin Sandstone in drill hole 10DDH039 located at the southern end of the Hardstaff Peninsula.

Results

A representative sample of the Wonganin Sandstone (PLV_8) was collected from metallurgical drill hole 10DDH039 and submitted for dry magnetic separation test work to determine if the sample could upgrade to a +40% pre-concentrate at 1mm, 2mm and 3mm grind sizes.

The crushed samples were subjected to dry low intensity magnetic separation (LIMS) followed by higher intensity rare earth magnetic separation (REMS) at a magnetic intensity of 1000 gauss and 6000 gauss respectively. The samples were crushed to 1mm, 2mm and 3mm.

The material from each grind size test was collected, weighed and assayed for iron.

The head (feed) iron assay grade of sample PLV_8 was calculated to be 29.1% iron at 1mm and 28.1% iron at 2mm and 3mm.

The results from the dry magnetic separation test work at 1mm, 2mm and 3mm including mass recovery and iron grade is given in the following table (see link at the bottom of the release).

The bench scale tests indicate that a pre-concentrate grading +40% iron was achieved from PLV_8 at grind sizes of 1mm, 2mm and 3mm with an iron feed grades of 29.1% iron and 28.1% iron respectively.

The result further indicates that additional bench scale test work on the Wonganin Sandstone and Yampi Member from the Hardstaff Peninsula be conducted at a coarser 3mm grind size as there does not appear to be any significant grade benefit in crushing the test work samples down to 1mm.

Comments

Managing Director Tony Schoer said: "The results of the dry magnetic separation test work on the Wonganin Sandstone sample PLV_8 are encouraging in that they demonstrate we may be able to produce a pre-concentrate with grades above +40% iron at coarser grind sizes. This has the potential to offer significant cost benefits to the Project if grinding down to 1mm is not required".

"Based on this result, we are in the process of selecting a number of drill core composite samples from both the Wonganin Sandstone and Yampi Member at the Hardstaff Peninsula to undergo further dry magnetic separation test work at a 3mm grind size. We expect to submit these samples for test work by the end of the month and report the results when received".

For the complete Pluton Resources announcement including figures and tables, please view the following link:
http://www.abnnewswire.net/media/en/docs/357666.pdf

Contact

Mr. Tony Schoer Managing Director and Chief Executive Officer Mob: +61-411-232-711 Email: tschoer@plutonresources.com