FOR THE THREE MONTHS ENDED 31 MARCH 2012 PROMINENT HILL CONTAINED METAL PRODUCTION MARCH 2012 QUARTER TOTAL COPPER (TONNES) 27,182 TOTAL GOLD (OUNCES) 38,887 OZMINERALS.COM C1 CASH COSTS US96.9c/lb HIGHLIGHTS Strong operating performance at Prominent Hill. Production impact from rain event minimised. C1 Cash Costs affected by reduced ore mining rates, increased waste mining and a strong Australian dollar - but overall costs in line with expectations. First ore achieved from underground stoping operations. New open pit mining contract signed. Further drilling results from Carrapateena confirm and extend known mineralisation. New concentrates handling system commissioned. Completion of Cambodian asset sale scheduled for May 2012. Terry Burgess Managing Director and Chief Executive Officer 26 April 2012
OZ MINERALS LIMITED ABN40 005 482 824 OZ MINERALS QUARTERLY ACTIVITIES TO 31 MARCH 2012 SUMMARY In the first quarter, a strong operating performance at Prominent Hill was achieved with production of 27,182 tonnes of copper and 38,887 ounces of gold contained in concentrate and sale of 41,667 tonnes of concentrate. Over three days in late February/early March, significant rain fell at Prominent Hill, the heaviest since commencing operations in 2009. While protection systems worked effectively and no equipment was damaged, this rainfall resulted in restricted access to some areas of the pit, in particular to Stage 2, until the rain that fell in the pit was pumped out to the tailings storage facility by the end of the first week in April. As a result of the lower ore mining activity during the quarter, ore feed was maintained by drawing on ROM stockpiles. As a consequence of the lower mining rate, unit costs were increased for the period. The new mining contract signed with Thiess during the quarter will provide a range of cost and productivity benefits to OZ Minerals. The changed roster included in this contract has required additional personnel to be recruited and trained by Thiess, a process that is now largely complete. The Ankata underground mine achieved an important milestone by producing first ore from stoping at the end of quarter, thereby meeting the project schedule. A rigorous exploration program continued in the Prominent Hill near mine and regional areas with a significant geophysics program conducted in the mine corridor to locate drill targets. At Carrapateena the in-fill drill program continued with excellent results from two further holes, again extending the mineralisation of the higher grade zones. SAFETY Safety performance in the March quarter saw a continuing steady improvement. The lost time injury frequency rate per one million hours decreased to 0.85 in the quarter and the total recordable injury frequency rate per one million hours decreased to 17.35. There were no lost time injuries for the quarter and two fewer recordable injuries than the previous quarter. The major improvement program to address safety performance that commenced in late 2010 continued during the quarter, with over 100 peer-on-peer behavioural safety observers now trained. OPERATIONS Significant Rain Event As part of significant rains in south eastern Australia, the region around Prominent Hill experienced heavy rain fall over a three day period and received almost its entire annual rainfall in late February and early March, with the Prominent Hill site having 150mm of rain. While the rain water bund protection systems prevented any ingress of water into the pit area, the direct rainfall resulted in approximately 40 megalitres of water collected at the bottom of the pit in Stage 2. However, no equipment was damaged as a result. Stage 2, which is the main source of ore mining under the current mine plan, was dewatered after installation over three kilometres of pipe and a two-stage pumping system, with mining operations in Stage 2 recommencing on 8 April. Mining Overall material moved in the pit was above the prior quarter. Total ore mined for the quarter of 1.94 Mt was below the previous quarter but in line with the mine plan which, as foreshadowed, has a higher strip ratio in 2012 in part associated with the north wall cutback. Waste mined was above the previous quarter s tonnage, but below plan, as priority was given to material movement in Stage 3 of the open pit. Mined grade for copper for the quarter of 1.11 percent was below that of the previous quarter, as a result of lower grade ore mined from Stage 3 compared with Stage 2 ore, which could not be accessed after the rain event. Processing The plant continued to perform well throughout the quarter with throughput of 2.46Mt of ore, being marginally above the previous quarter. With limited ore mined during the quarter, there was a lack of direct feed from the mine and the main feed to the processing plant was from ROM stocks. This marginally reduced copper recovery for the quarter as the ROM stocks included aged (oxidised) ore. The gold production was marginally above the previous quarter primarily reflecting better grades together with slightly higher ore milled. Total production for the first quarter of 27,182 tonnes of copper and 38,887 ounces of gold in concentrates is in line with 2012 guidance of 100,000-110,000 tonnes of copper and 130,000-150,000 ounces of gold. 2
Ankata Underground Mine First ore from stoping was achieved from the Ankata underground mine at the end of the quarter in line with expectations. The continued ramp-up to the full production rate of 1.2 million tonnes per annum is planned by the end of the third quarter of 2012. All revenue and expenses related to the Ankata underground mine will be capitalised until mine facilities and equipment are fully commissioned. The underground development remains on track and is in-line with the previously stated budget of $148 million, with approximately 75 percent of the overall project being complete at the end of the quarter. TABLE 1 PROMINENT HILL PRODUCTION STATISTICS MINED ORE (TONNES) WASTE (TONNES) DEC 11 MAR 12 2,212,157 1,945,417 14,266,345 16,102,251 MINED GRADE COPPER (%) 1.28 1.11 GOLD (G/T) 0.47 0.49 SILVER (G/T) 3.18 2.88 ORE MILLED (TONNES) 2,442,800 2,460,397 MILLED GRADE COPPER (%) 1.22 1.24 GOLD (G/T) 0.61 0.63 SILVER (G/T) 3.03 3.15 RECOVERY COPPER (%) 89.9 89.2 GOLD (%) 78.6 77.9 Costs C1 cash costs of production for the quarter were US96.9c/lb, which was higher than the previous quarter reflecting the higher drawdown of ROM stocks (ore inventory adjustment) during the quarter as more ore was milled than mined, together with a stronger Australian dollar against the US dollar. Excluding these impacts the C1 unit cost performance was largely in line with the previous quarter. The increase in mining costs in the period was mainly due to increased mining activity and associated mobilisation costs for additional mining equipment and labour as planned. The reduced ore mined for the quarter resulted in a higher strip ratio (above the life of mine strip ratio) and hence increased deferred mining costs. TABLE 2 PROMINENT HILL UNIT COST PERFORMANCE DEC '11 MAR 12 MINING COSTS 129.5 153.5 DEFERRED MINING (16.0) (45.1) ORE INVENTORY ADJ (8.9) 12.4 TOTAL MINING COSTS 104.6 120.8 TOTAL SITE PROCESSING COSTS 47.2 46.1 TC AND TRANSPORT 28.2 29.8 NET BY-PRODUCT CREDIT (INCL PROCESSING/TC/RC/TRANSPORT) (115.6) (118.5) OTHER DIRECT CASH COSTS 19.8 18.7 TOTAL C1 COSTS 84.2 96.9 ROYALTIES 6.5 7.0 OTHER INDIRECT COSTS 30.6 23.9 COPPER CONCENTRATE PRODUCED CONCENTRATE GRADE CONTAINED METAL IN CONCENTRATES PRODUCED TOTAL CONCENTRATE SOLD SILVER (%) 71.0 77.9 TONNES 53,163 55,322 COPPER (%) 50.4 49.1 GOLD (G/T) 22.1 21.9 SILVER (G/T) 98.7 109.1 COPPER (TONNES) 26,802 27,182 GOLD (OZ) 37,814 38,887 SILVER (OZ) 168,782 194,000 (DM TONNES) 56,450 41,677 TOTAL CASH COSTS 121.3 127.8 D&A 64.6 66.0 OTHER NON CASH COSTS 0.9 2.9 TOTAL PRODUCTION COSTS 186.8 196.7 New Mining Contract In early February, a new six-year contract was signed with Thiess Pty Ltd for the provision of mining services to OZ Minerals Prominent Hill open pit mining operations. At the same time, it was agreed that OZ Minerals would purchase certain items of mining equipment to be used by Thiess in the provision of the mining services. The total purchase price for the equipment is approximately $60 million. This arrangement is expected to result in overall cost savings for OZ Minerals. 3
EXPLORATION PROMINENT HILL Near Mine Exploration Surface diamond drilling continued with two to three rigs within the mining lease area. Sixteen holes for 11,520 metres were completed to test a combination of geophysical, geological and structural targets outside of the Malu-Kalaya-Ankata corridor. Widespread native copper was intersected in several recent broadly-spaced drill holes located within the southern portion of the mining lease. Follow up drilling is planned with assay data still awaited for the holes showing native copper. The mineralised zone continues south into the adjoining OZ Minerals exploration tenement. No significant assay results have been received to date for drilling in the March quarter. Exploration drilling of the gold-rich area of the Kalaya copper-gold resource from the Ankata decline continued during the quarter with one rig for a total of 1,324 metres. Significant intersections include; PH11D5108 23 metres @ 2.6g/t Au from 448 metres PH11D5108 6 metres @ 2.9g/t Au from 253 metres 12 metres @ 2.1g/t Au from 300 metres Development of the Malu exploration decline back towards the east to provide drilling access beneath the open pit reached 445 metres with approximately 1,450 metres remaining. The decline is expected to be complete in Q4 2012 with exploration drilling to commence on the resource beneath the Malu open pit from stockpile cuddies off this decline in the second half of 2012. Regional Exploration The regional exploration program continued with two diamond rigs drilling at Cressida, Kennedy Dam, Tahemi, Bulgunnia Fault, Bluebird South and Prominent Hill South. The prospect locations drilled are shown on page 10 of the accompanying presentation. Twelve holes for 8,430 metres were completed which includes several holes testing the southward extension of the native copper intersections referred to above. In addition, significant brecciation with haematite infill has been identified in rocks resembling the Prominent Hill mine sequence at Bluebird South, approximately 20 kilometres west of the mine. Further drilling is planned around Bluebird South. Geophysical surveys (ground gravity, induced polarisation (IP) and electromagnetic (EM)) continued during the quarter. A major seismic survey began late in the month on selected traverses to highlight major regional structures in the southern half of the project area. One traverse has been designed to pass to the immediate east of the mine. All traverses are being covered by ground gravity surveys to assist with the interpretation of the seismic data. Slide 9 shows the distribution of the geophysical surveys undertaken during the March quarter. IMX Joint Venture During the quarter seven holes for 4,730 metres were drilled with one diamond rig on the IMX joint venture ground to test geophysical anomalies at Aquila, Fyans and Brumby. The rock sequence intersected at Fyans and Brumby appears similar to that at Prominent Hill with some brecciation and haematite infill recorded. Follow-up drilling is being planned Ground gravity was undertaken across the Southern Domain area and a seismic traverse was run across the south-eastern portion of the tenement boundary to define major regional structures. CARRAPATEENA Exploration The exploration program at Carrapateena continued with focus on infill drilling to convert previously announced inferred resource to indicated resources. During the quarter, five drill holes were completed for 10,310 metres with a further four holes in progress. Most completed holes successfully targeted the inferred resource and were also designed to test for extensions to the previously defined pipe like body of mineralisation. Drilling to date has been highly encouraging with most completed holes showing mineralised extensions to the existing model. As an example, hole number 078 shown in slide 12 extended the known high grade lower bornite mineralisation by over 50 metres further to the west. Currently drilling is focussed on assessing possible extensions to the known mineralisation further to the north. 4
Significant results received from the third (DD11CAR077) and fourth (DD11CAR078) holes included: DD11CAR077 450 metres @ 1.24% copper and 0.59g/t gold from 668 metres Including: 203.7 metres @ 1.87% copper and 0.93g/t gold from 810 metres DD11CAR078 658 metres @ 1.97% copper and 0.67g/t gold from 741 metres Including: 430.5 metres @ 2.34% copper and 0.73g/t gold from 879.5 metres SALES & MARKETING Shipments of Prominent Hill concentrates for the quarter totalled 41,677 tonnes, containing 20,496 tonnes copper and 30,363 ounces gold. Shipments for the quarter utilised the new containers and were offloaded at the Port of Adelaide with the newly commissioned offloading system. Approximately 2,000 tonnes of concentrate stored in Darwin prior to the Edith River incident was exported during the quarter. Exports through Darwin will not resume until after additional planned bridge repairs are completed at Edith River. CORPORATE Edith River Update As reported in the previous Quarterly Report, a mixed freight train operated by Genesee & Wyoming derailed at Edith River in late December 2011 spilling copper concentrate. Copper concentrate and material contaminated with sand has been removed from the Edith River site to Prominent Hill and a significant amount of this material is in the process of being retreated in the plant circuit. OZ Minerals conducts regular monitoring of the Edith River derailment site and will carry out further remediation work, as necessary, in the dry season. On Market Share Buy-Back OZ Minerals commenced its on-market share buy-back program on 17 August, 2011. By 11 April, 2012 the Company had bought back 13,995,774 shares at an average price of $10.41 representing $145.6 million. The designated amount for the buy-back program is up to $200 million and will end no later than 16 August, 2012. Cambodia On 20 February, OZ Minerals signed a Sale and Purchase agreement with Renaissance Minerals Limited for the sale of its Cambodian assets for $17.8 million in cash, shares and options in Renaissance, along with possible future payments of a further $22.5 million upon the achievement of certain milestones. Further details of these milestones are highlighted in the release made on 20 February 2012. SHARE REGISTRY Link Market Services Limited Level 1, 333 Collins Street, Melbourne VIC, 3000 Australia Telephone Australia: 1300 306 089 Telephone International: +61 (2) 8280 7763 Facsimile: +61 (2) 9287 0303 registrars@linkmarketservices.com.au CORPORATE INFORMATION ISSUED SHARE CAPITAL AT 24 APRIL 2012 ORDINARY SHARES 309,881,740 UNLISTED OPTIONS 100,000 SHARE PRICE ACTIVITY FOR THE MARCH QUARTER (CLOSING PRICE) HIGH $11.50 LOW $9.53 LAST $9.42 (24 APRIL 2012) AVERAGE DAILY VOLUME 1.46 MILLION SHARES REGISTERED OFFICE Level 10, 31 Queen Street Melbourne, VIC 3000 GPO Box 1291K, Melbourne, VIC 3001 Telephone: +61 (3) 9288 0333 Fax: +61 (3) 9288 0300 5
INVESTOR AND MEDIA ENQUIRIES CONTACT INVESTORS James Deo Head of Investor Relations Telephone: +61 (3) 9288 0352 Email: james.deo@ozminerals.com MEDIA Rachel Eaves General Manager Public Affairs & Sustainability Telephone: +61 (3) 9288 0252 Email: rachel.eaves@ozminerals.com WITHIN THIS PRESENTATION REFERENCES TO EXPLORATION RESULTS RELATING TO PROMINENT HILL AND CARRAPATEENA THIS INFORMATION HAS BEEN APPROVED FOR RELEASE IN THE FORM AND CONTEXT IN WHICH IT APPEARS BY MR JIM HODGKISON WHO IS A FULL TIME EMPLOYEE OF OZ MINERALS AND HAS SUFFICIENT EXPERIENCE WHICH IS RELEVANT TO THE STYLE OF MINERALISATION AND TYPE OF DEPOSIT UNDER CONSIDERATION AND TO THE ACTIVITY UNDERTAKEN TO QUALIFY AS A COMPETENT PERSON AS DEFINED IN THE 2004 EDITION OF THE AUSTRALASIAN CODE FOR REPORTING OF EXPLORATION RESULTS, MINERAL RESOURCES AND ORE RESERVES. WITHIN THIS STATEMENT (OR PRESENTATION) REFERENCES TO EXPLORATION RESULTS RELATING TO PROMINENT HILL ARE BASED ON INFORMATION COMPILED BY MR MARCEL VAN ECK MSC WHO IS A FULL-TIME EMPLOYEE OF OZ MINERALS, IS A MEMBER OF THE AUSTRALIAN INSTITUTE OF GEOSCIENTISTS AND HAS SUFFICIENT EXPERIENCE RELEVANT TO THE STYLE OF MINERALISATION AND TYPE OF DEPOSIT UNDER CONSIDERATION AND TO THE ACTIVITIES UNDERTAKEN TO QUALIFY AS A COMPETENT PERSON AS DEFINED BY THE JORC CODE (2004). MR VAN ECK HAS CONSENTED TO THE INCLUSION OF THE MATERIAL IN THE FORM AND CONTEXT IN WHICH IT APPEARS. ALL OTHER REFERENCES TO EXPLORATION RESULTS WITHIN THIS PRESENTATION / STATEMENT ARE BASED ON INFORMATION COMPILED BY MR A HOUSTON BSC WHO IS A FULL-TIME EMPLOYEE OF OZ MINERALS, IS A MEMBER OF THE AUSTRALIAN INSTITUTE OF GEOSCIENTISTS AND HAS SUFFICIENT EXPERIENCE RELEVANT TO THE STYLE OF MINERALISATION AND TYPE OF DEPOSIT UNDER CONSIDERATION AND TO THE ACTIVITIES UNDERTAKEN TO QUALIFY AS A COMPETENT PERSON AS DEFINED BY THE JORC CODE (2004). MR HOUSTON HAS CONSENTED TO THE INCLUSION OF THE MATERIAL IN THE FORM AND CONTEXT IN WHICH IT APPEARS WITHIN THIS PRESENTATION REFERENCES TO EXPLORATION RESULTS RELATING TO PROMINENT HILL AND CARRAPATEENA OZMINERALS.COM 6