I would now like to hand the conference over to Mr. Andrew Graham, interim Chief Executive Officer. Please go ahead.
Thanks, Melanie. Thanks to everyone for joining us this morning to hear about our, what are our strong set of results for the March quarter. On the call with me today is Martin Cummings, our CFO, and Peter Trout, our COO. That you can follow along, we've released the presentation that we'll refer to during this call on the ASX website, and we'll refer to the slides as we go through those. Just to provide a bit of context before I turn to the slide pack, overall, we think this is a very strong set of results for the quarter, and we're very pleased to be able to share those with you today. Just touching on a few high points, given the strong result extended across the board in the business.
Firstly, there's a real step change in operating performance, 26,000 ounces produced, all-in sustaining costs of AUD 1,884. Certainly a material improvement from where we were from the December quarter. Definitely as we get to later on, gives us confidence in our guidance for the year. With that, obviously it flows from that strong cash flow, pleasingly across all of our assets. Operating cash flow from the asset in excess of AUD 30 billion and has allowed us to extend our cash balance to over AUD 39 billion at the 31st of March. It puts us in a much stronger position than where we were. We obviously released the generation update last week.
We'll talk a bit about that today, because we recognize we haven't given shareholders a chance to hear from us on that yet, other than through the announcement, and also a chance to ask questions on that. Finally, from, you know, despite the focus on cash and costs, we have been investing in exploration. We recognize the importance of that, and you've all seen through the quarter, some strong results come out from our exploration programs, both in and near mine at Peak, but then also, some regional IP work we were doing around Hera. I will now turn to the slide pack and start on slide four. I suppose the point is that those strong set of results isn't possible without the input of everyone in our business.
One of the things that's really been pleasing me is the fact that every single person in our business is really pushing to a common goal, working together to improve the business and deliver some strong results. I'm pleased for the whole team that we're able to put out such a strong set of quarterly results today. It's good reward for all of that effort. One of the more telling items to report on is safety. Extremely pleased to be able to say we had no recordable injuries throughout that first quarter. People often say that a strong safety performance goes hand in hand with a strong operational performance. This is probably further evidence of that.
You know, I think it's pretty clear that when people know what they're meant to be doing, if they're focused on what they're doing, have thought about their task, have planned ahead about their task, you get a good safety result. Similarly, you get a good production result. We've certainly seen that. The other pleasing bit with that, it was not at the time of, you know, huge stability within the business. If you think about what's occurred through the quarter, Hera did come to the end of its life. We started taking the plant to care and maintenance during the quarter. Similarly at Peak hasn't been without its changes.
I mean, we have fully demobilized PYBAR, for example, from Peak, by the end of that quarter as well, moving very much to under-operated mining. In a relatively unstable period for the business to get no recordable injuries, a fantastic outcome. You know, my hat's off to everyone in the business for achieving that. Just to touch on the right-hand graph on that slide, recordable environmental incidents. We did have one to talk through. A minor in that we had a minor fire at the batch plant at Peak, in a storage area. Came from a faulty light bulb, and smoke leaving the site being classified as recordable environmental incident, but certainly no lasting consequence on that one. I want to turn to the next slide then, slide five, for those following along, on the outlook for the business.
Summarized our results for the year to date, the half one plus the March quarter, against our guidance. I can say, as I've alluded to earlier, that we are maintaining guidance, based on the performance of the business, to this point, three-quarters of the way through the financial year. Gold, we had a particularly strong quarter, and we're now tracking at 85% of our guidance for the year. It puts us in a very strong position to haul home that gold production. Similarly with the other commodities, they're all sitting at 75%, 77%, of our full-year guidance. Three-quarters of the way through the year, it's a good place to find ourselves and gives us every confidence that we can achieve guidance across the board.
All-in sustaining, I know we had a number of questions from people in the past, you know, with the half one sitting at AUD 2,600 as to whether the AUD 2,300 guidance was achievable. Certainly, you know, below AUD 1,900 for the March quarter, it gives again every confidence that that guidance number is certainly achievable. Going forward, just thinking about what's coming to us, you know, I wouldn't want to take this quarter and just project it straight out into the last quarter of the year. There are a few things, as everyone knows, and as I mentioned earlier, Hera has moved to care and maintenance, so we do lose that production from Hera. We'll talk about...
Peter will talk about that in a little bit more detail in a moment, just around the strong finish it did have. Just be assured that that was factored into our guidance when we set that in December. It's not as though there's anything new or surprising in that change. This quarter also two items which we're working through actually this month, just as a regular routine piece, realigning of the mill at Peak will be done. Also we will be installing a man-riding cage in the shaft at Peak, which will result in some south mine downtime during that period. However, we will be relocating people into the north mine while that gets done.
The real big win for us on that is the speed at which we can then get people to and from the job at Peak, which will give us some real benefits. Anyway, I think it's... I'll pause at that point, in the sort of overarching elements, and you're probably very interested in the details of how things played out through each of the sites. On that note, I might hand across to Peter, who can then take us through the site slides from that deck.
Thanks, Andrew. Just to pick up on Andrew's comments here, it's really pleasing to report a good set of results for the March quarter, particularly given the changes happening at our Peak and Hera sites and delivering those changes and those good metal production results without a serious injury across our operations. I'll pick up on the slight site discussions, starting with slide six, the Peak mine. I guess the highlight for the quarter for Peak was the higher grades that we were mining from the underground operations there, which clearly flowed through into the better metal production. Ore was mined from 5 different areas across the north and the south mine, and we saw scoping fronts in a couple of those areas move into higher grade zones as we progressed through the scoping sequence.
Probably the more pronounced grades we saw were in the Chronos deposit, particularly for lead zinc, and Perseverance Deep for gold. In fact, the gold grade benefited from a positive reconciliation against the geological model over the campaigns we ran in the quarter. In terms of mined ore production, we were looking to get higher output for the quarter, but we were held back by some poor drill and blast results in two of our stopes early in the quarter, and also from labor availability in some of our contracted services. We've addressed most of those issues now and looking forward with our owner mining crews, which are now fully resourced to put that behind us. As Andrew mentioned, during the quarter, the underground mining services contract with PYBAR was finished up by mutual agreement at the end of March.
As part of that change, Redpath came in to take over the long haul drilling and cable bolting services from the start of April. What this allowed us to do is effectively bring forward, at low cost, the final stage of the owner mining transition. We now have ownership of the core mining fleet at Peak, and we're using that to start to drive some productivity improvements across the site. In the process plant, volumes were restricted at times by lower mined ore tonnages, which was particularly early in the quarter, and some periods of very high lead zinc grades that reduced the throughput rates and impacted also the zinc recovery to concentrate.
At periods, we were mining combined lead zinc grades above 30%, the only other source we had available for blending was running at 12% combined, which did cause us to throttle back the plant performance there. Where possible, we do blend the lead zinc ores to maintain a consistent feed grade through the float circuit. When we're able to do that, we do see better recovery and concentrate grades. In fact, in March, we ran a trial to mimic the grind size and the flotation reagent conditions for federation ore, were able to see some good results there over a week-long period where we could provide steady state feed to the float circuit. I think another positive trend from Peak is a sustained reduction in mining costs, which we reported on in the December quarter.
We've also identified some further cost and productivity improvements. We're pursuing those through the remainder of this calendar year, seeking to maintain and improve our cash margin. As we move now to slide seven, I would really like to commend our Hera team for what was an outstanding quarterly result. In fact, they outperformed the modified production plan that we announced in December. The chart on slide seven of the presentation deck shows the 43% improvement in gold production and also the reduction in all-in sustaining costs to about $1,700 per ounce. What a change that was from the December quarter. Our management team at site, our employees across the business, our site contractors really did a great job dealing with some difficult conditions.
Our plan was to run hard right through to the end and come to a short, sharp stop, and that's exactly what the site team delivered. We did have the benefit of lateral development that we finished in the earlier part of this financial year, to stope from three different mining areas. What that meant is we could sustain good ore delivery to the surface, and the process plant could run unconstrained at full capacity. That was the key driver to the higher precious and base metal production. That's on a bit of a sadder note. Processing operations finished on the 27th of March, and the site has quickly transitioned into care and maintenance preparations. We recovered all the valuable assets from the underground mine and actually turned off the primary fan and sealed the portal.
Our mining contractor, Redpath, has demobilized from site and have left those key pieces of mining equipment that we require to restart the Federation decline development. Our surface contractors are currently demobilizing, and we're tracking very well to place the process plant into hibernation by the end of April. I think given the transition to care and maintenance at Hera and what that means, it's worth looking back on the contribution that Hera has made to our company and the local community. The project was commissioned in 2014 as Australia's first operating asset, and was expected to extract about 1.9 million tons over a five and a half year operating life.
Since commissioning, however, the mine has produced 3.2 million tons of ore over nine years, which supported 180 full-time jobs and contributed about AUD 216 million to the local economy, which is an outstanding outcome. We're now looking forward to the next chapter of mining in the district with the development of the Federation project, and it's pertinent to point out that the Federation project already has a 4 million ton Production Target in front of it. Moving now to slide eight, just to talk to the performance at our Dargues Mine. You'll see that quarterly production increased there to about 9,600 ounces, and that flowed through to a healthy contribution in terms of group cash flow. The operation reached a couple of milestones during the quarter.
It processed its millionth ton of ore and also moved past 100,000 tons of gold production since commencing operations in 2019. We were able to process at higher rates during the quarter, thanks to the development consent modification received in December. Mill feed tonnage lifted by 9%, and that was the driver of the higher gold production. Our mine ore production did drop back a bit, and that was partly due to a very strong December quarterly result. The site team had to work through several slope production and backfill disruptions over the quarter and have got us now back on track. We had accumulated high opening ROM stocks, and that meant the mill processing volumes weren't impacted, although we did have some downtime events caused by some unplanned power outages.
In the underground mine, development advance again outperformed our expectations, and the decline has reached the lowest mining level. What this good progress allows us to do is to reduce development in the coming months, and we've already transferred one of the two development jumbos from Dargues to Peak to assist at Peak. As a final note on Dargues, we completed the underground infill and extensional diamond drilling program early in the quarter, and the results from that work are currently being incorporated into the site's life of mine plan update. At this early stage, it indicates that we will have a marginal mine life extension beyond that that was indicated in the Production Target released last October. On that note, I might hand over to Martin to talk about our financial outcomes.
Thanks, Peter. Turning to slide nine of the presentation, and as Andrew and Peter have outlined, the improved operating performance this quarter resulted in a significantly stronger financial position at the end of March. We finished with $39.3 million in unrestricted cash, up from $23.7 million at the end of December. This is an increase of over $15 million. Pleasingly, this is actually a genuine increase in cash with our metal sales and supply payments made all in line with our standard processes. All of our assets were cash positive and generated a combined $30.2 million of cash flow from the operations, around $10 million higher than the prior quarter. As Peter outlined at Peak, we benefited from both strong production and metal sales and lower costs, resulting in a cash flow of $14.4 million.
I'll note that this is lower than the December quarter. That prior period included concentrate sales relating to September. The team were able to finalize the mining contract with the PYBAR during March, which now supports our ongoing cost reduction activities as an owner miner. It did result in a favorable year to date drop in mining costs of around AUD 2 million. Dargues' cash flow of AUD 9.2 million was very strong this quarter compared to the AUD 1.6 million it generated in the prior quarter. We did sell around 1,700 more ounces this quarter from the sale of concentrate in December. It was still a very consistent quarter. Dargues' is now clearly benefiting from the recent strength in gold price. It is something we'll factor into our thinking about the strategy for the asset during its remaining life.
As Peter mentioned, Hera had a very strong finish to operations, with the transition to care and maintenance executed extremely well, and it did result in metal production and cash flow that exceeded our plans. There is some remaining concentrate and doré to sell this quarter, which will help offset costs associated with the move to care and maintenance and the payment of remaining supply invoices in April. Our growth in capital exploration spend has been maintained at minimal levels while we complete the refinance, with development spend on Federation to ramp up post that announcement. As I've updated on recent calls, in January, we received a tax refund of AUD 9.8 million relating to our FY22 tax return.
Given it's likely that we will incur another tax loss in the FY23 tax year, there is an opportunity under the loss carry back provisions for another tax refund once we submit the FY23 tax return later this calendar year. It is possible that tax refund could be higher than what we received for FY22. Now moving to our debt facilities. We made our regular quarterly repayment of AUD 4.05 million on the term loan and cashed back another AUD 5.1 million in performance bonds in March. Our term loan balance is now reduced to just AUD 8.6 million, and our restricted cash backing at the performance bonds has grown to AUD 46 million. The drawn balance of the performance bond facility is unchanged at AUD 56.8.
As we will close these facilities down, shortly when we establish the new facilities, we've made some changes in March that were possible due to our strong liquidity position. We chose not to extend the undrawn AUD 10 million working capital facility, which matured in March, given it was unlikely to be required in the near term. We also canceled the remaining headroom of AUD 8.2 million on the performance bond facility, as we have no requirement in the near term for further performance bonds to be lodged. Both adjustments mean we avoid paying unnecessary commitment fees to maintain those facilities. The final movement in the cash waterfall on this slide relates to working capital, which was an unfavorable movement of AUD 8.7 million. The primary driver of this is due to our lower trade creditors balance.
Our operations spent approximately AUD 17 million less this quarter relative to the prior quarter, which resulted in eight and a half million dollars less trade creditors at the end of March. We do expect this to come down further in April, as we finalize supplier payments in relation to Hera. As I mentioned earlier, we also have some sales to finalize which will help offset some of that from a cash perspective. I talked about the higher gold price earlier with DAR, but just to reiterate, Aurelia is benefiting from these higher gold prices right now with only a modest hedge book of just over 4,000 ounces hedged with deliveries out to September 2023. The average price of those contracts is AUD 2,640 an ounce, which is not materially lower than the current spot price.
We do have some quotation period hedges for recent concentrate shipments, but these are all very short-dated with contracts out to June. As we move into a capital-intensive phase with development of Federation, hedging is a tool that we will use to manage the balance sheet, but it will be done in a measured way that considers all of our metal exposures. Finally, in relation to the refinance, I can assure you it continues to be our top priority. The re-release of the Federation feasibility study update this month was an important input into financier due diligence, so we did need to sequence that release ahead of them finalizing a facility. We are in the midst of documenting terms at the moment, and once an announcement is made, we will commence remobilization of Redpath to Federation to restart development activities.
I do look forward to updating you on the new financing arrangements in due course. Thanks for your time this morning. I'll now hand the call back to Andrew.
Thanks, Martin. Thanks also, Peter, for those, very detailed and clear explanations. I am gonna pause briefly, though, on slide 10. Those following along will see a beautiful photograph of one of our sites in the early morning. Just as an example of some of the things we're doing around cost improvement, the fact it's embedded in everything we're doing. We did recognize we needed some updated photographs of our sites. We could have got an expensive professional photographer to go and do that. Given they'd only be there for a short period, they probably wouldn't have captured the essence of our sites. Instead, you know, Bright Star in the organization decided to run a competition where employees were able to take photographs and submit them.
In time, there will be a winner, and there will be a calendar that comes out with those photographs. That's one of the photos displayed there on slide 10. All part of our Working Smarter program, which is a good segue into slide 11, where we just touch a little bit on what we're doing around organizational renewal. I've talked about this quite a bit in the past. You know, I think there's are nine ticks on this page. You know, it's a small subset of a very large number of things that we are doing across the business. I've chosen to highlight a few of those this morning. Working through site by site, Hera and Federation, it's been mentioned a few times, that strong finish to the Hera operation in its life.
You know, credit to Rob and Nick down there on site for really driving that outcome and the entire team. The conditions to the end required management, the team there certainly managed them extremely well. You know, everything we had hoped to do in December when we talked about the new mine plan, we have been able to do. As mentioned earlier, care and maintenance is expected to wrap up tomorrow. The other elements in there, obviously, Federation development consent we've talked about in the past. It's a very important step for us. It really unlocked the ability to bring forward tons at Federation into production, therefore bring forward revenue. Peter will talk a little bit about that in a moment when we talk about Federation optimization.
That's the third tick I've got there against Hera Fed. We obviously put out the Federation update last week and included a very large number of initiatives to really bring down cost and more than offset the inflationary impacts we're seeing. We'll talk a little bit about that as well, but in a very important step for us. Going forward to Hera and Federation, finalizing that care and maintenance at Hera, and as I mentioned, it's going well, so it will be done as expected fairly swiftly. Then as Martin has mentioned, once funding is secured, we'll then begin the remobilization to the Federation site. I'm still expecting that in this current quarter. At Peak, a lot of work going on. Peter mentioned the transition to owner mining.
You know, we'd like to thank PYBAR for their contribution there at Peak. I take the view that if you've chosen to be an owner miner, you should be an owner miner. This transition needed to end. It was good we were able to do that in a sort of mutually agreeable way and allow us now to really focus on making the most of Peak with our own people operating our own equipment. It's nice to see that transition now in place, and it gives our new general manager there the tools and the ability to get on and take Peak to where we know it can go. One of the strengths of Peak is it's been a very strong contributor to our Working Smarter program.
Even yesterday we have a winner each month on idea generation and the quality of those, and I think the last two winners came from Peak. It's really great to see ideas still flowing to improve our assets across the board and our company across the board. We've had some fantastic traction through our Working Smarter program. Peak, though, we do recognize it can do better. A real focus for us starting through this quarter is an ongoing improvement program, but more of a step. What can we do differently at Peak, you know, to make its overall unit cost lower, to improve its productivities?
We see, and the team there have already identified a number of things that we can be doing that will flow into a broader piece I've talked about in the past around the optimization of Cobar for us, as opposed to thinking about our Cobar asset as a series of discrete operations. What can we do to optimize the overall value we can get from our Cobar business? Touching on Dargues, you know, it was mentioned the processing limit increase that we got through December has certainly paid dividends for us and continues to with higher throughput than we otherwise would have been able to do. It itself has been a strong contributor to Working Smarter, which is excellent. It's already run well, Dargues. Its costs are competitive.
There's always ways to work better, and it's really great to see that team embrace that. The other one that was mentioned by Peter, that additional expansion on infill drilling is finalized. Asset is coming back. We're now thinking about how that flows through to the life of mine plan, which is well and truly in progress at the moment. I mentioned that we wanted to talk a little bit about the Federation update. I recognize we put that out last week. We didn't have a call around that knowing this quarterly call wasn't too far off.
Just at a very high level before I pass over to Peter, I had said, you know, to go all the way back to the AGM, the feasibility study in my mind is never a finished piece of work that you don't ever reopen. We always recognize there was things that we could do to further improve that study and further improve the project. The goal through this piece of work was to try to capture some of that. You know, obviously we'll see every day the inflation environment we're in. We've certainly seen other projects in the industry see their capital costs run away from them on the back of that higher inflationary environment. We're not immune from that. We insulated somewhat into the not building a new plant, and we're just building a mine.
You know, we've got lower capital spend and less exposure to things like equipment and those sorts of things. We're not immune from it. One of the hopes through this update was that we were able to combat that inflation. You'll see, you know, as you can on slide 12, at the table on the bottom, certainly, you know, capital to first scope ore. We've certainly combated that inflation in that space through a whole bunch of means.
That was, for me, you kind of can look at the release and look at the total capital, AUD 143 versus AUD 145, and think, "Oh, not much has changed." The reality is, there's a lot of things we've done, and assuming the overall project to really fight that inflation come in at a competitive cost and also improve the operability and the timing of cash flow from that asset. Very, very pleased with the outcome of that update. One of the benefits we had was Hera moving to care and maintenance when it did. We had already assumed some benefit from Federation being 10 kilometers away from, you know, the fully operational Hera mine.
However, now that it's moved to care and maintenance, we've been able to really take advantage of what Hera had, particularly some of the underground equipment. I'll let Peter talk a bit more about all of that. Passing over to you, Peter.
Okay, Andrew. Thank you. I guess, in terms of what we've done at Federation, we've really looked at three main areas. The first is the mine design and the mine plan. The second one is looking at scope refinements. As Andrew says, with some of the changes happening in the business and just some time and perspective on things, we've been able to make some positive impacts there. Lastly, and combined with that, is a revised cost estimate. The good thing about that is we've maintained some pretty compelling project economics for Federation, and that's despite a reduction in the zinc price, if we look at the like-for-like spot price, NPVs compared to the October feasibility study announcements. Going on to slide 12, I thought it would be helpful to expand on some of those points.
Firstly with the mine design. We've gone through and looked at that and just made some changes to the layout. Principally there is the reduction in the gradient of the access decline, taking that to a slightly shallower gradient. It does two things for us. The first one is that we can move to a figure-eight layout in plan view rather than the spiral we had in the feasibility study. That layout actually extends the access of the decline and gives us a better platform to conduct infill drilling along the strike length of the deposit. Of course, the lower gradient, whilst it might add some meters into the initial development requirements, it does support higher truck productivities.
Also, given the change to the timing exploration decline and the recent receipt of the project's development consent, it has allowed us to bring forward stope ore production compared to what we'd allowed for in the feasibility study. The feasibility study had assumed that the exploration licence would still be valid, and the mining lease and associated development consent would not have been granted at the time we'd accessed ore. We see that circumstances changing now, and that has allowed us to bring forward some stope ore. That ore we prioritize to feed to our Peak process plant, with the aim of fully utilizing that capacity before we restart the Hera process plant.
Apart from the unit cost benefits that will derive at Peak, it also allows us to have higher pay abilities for the metal that goes out in the lead and the zinc concentrates. That compares to a combined lead and zinc concentrate that could be produced from Hera. That's a departure from the feasibility study, which was based on operations at Hera continuing until 2024. We've also had time to refine the scope elements and the site layout, and they'll provide us with some more confidence around the capital cost estimate, also allowed some of the CapEx to be reduced or deferred. An example here is the regrind mill planned for Peak, where we had carried forward a higher level estimate.
We've now done some more detailed engineering, that gives us more confidence in the pricing that sits behind that installation. We're also looking to move the tailings filter and storage shed from the Hera site to Peak. That gives us a lower risk pathway to delivering the volume of tailings we need for paste fill at Federation. In other areas, we've actually compressed the site footprint, just some of the experience we gained during the initial development of the site and a fresh set of eyes to it. For example, the services corridor between the two sites. We're able to trim back the amount of vegetation disturbance there. As well as reduction in land clearing costs, it's also allowed us to remove some of the biodiversity payments we'd have to make for the disturbance of that vegetation.
Lastly, as Andrew's mentioned, the transition to care and maintenance at Hera has allowed some of our existing assets and infrastructure to be used instead of purchasing new items, which is what the feasibility study assumed, given the assumed concurrent production from both sites. Things like refuge chambers, pump stations, secondary fans, jumbo boxes, those sort of things, did not have to be purchased new, and we're actually allowed to refurbish those items from Hera.
We'd also allowed for a temporary construction camp to accommodate the additional personnel. That's no longer required, and that's a direct benefit of about AUD 2.7 million to the CapEx. All in all, we're really, really pleased with the outcome of the feasibility study update, and we're now preparing ourselves for project execution activities and looking to resume site activities towards the end of the June quarter. Andrew, I might hand back over to you.
Great. Thanks for that extra detail, Peter. Just to wrap up the last slide then, the one we covered today, slide 13, just on exploration. You will recall when we were thinking about where we're up to as a business and looking at what we needed to do around cash management, we did pull back quite heavily on some particularly surface exploration holes. We did, however, continue to retain in our plans and now execute. We're going to continue to execute underground drilling at Peak. Part of that particularly is we know the value of what we find at Peak near mine, and if it's close to development, and it's a step out to an extension, those tons can very quickly turn up in a mine plan and turn up in a mill and turn up as revenue.
It is an important piece for us as a business to continue to do. We have had some great success this year, as we put out in our release, you know, towards the end of March. Some three items just to touch on then. Stepping away from workings, I suppose, and, you know, the Chesney East gold lands, you can't get much closer to the workings. 10 meters from existing underground development. I'll just put an example in here, 9 M at 21 grams gold. There's plenty of other good drilling in the release that went out in March, from that. You know, obviously, given its proximity to existing workings, our ability to turn that into something in a mine plan, quite readily is there.
The team on site at Peak are thinking about that at the moment as to how and when that may come into the plan. Really great, and I'm sure as we continue to drill, we'll find more of these types of things at Peak. Stepping a little further out, we're not talking far, 100 meters from existing underground workings, at Burrabungie. You know, 16 meters and almost 2% copper. That's just an example there from the drilling. Definitely an interesting piece. It's not that far from surface.
There is a bit of a gap between Chesney and Burrabungie that it's a plan now for us to drill from underground out of Chesney in the back end of this financial year or early in the next, to see whether there's continuity of mineralization between Chesney and Burrabungie. It's very exciting. Good to see good copper grades in there, and something we'll continue to follow up. Short one just to touch on, as we did in the March release, was Queen Bee. You know, looking now 10 Ks from Peak, so still absolutely within a very, very easy trucking distance. Some exceptional copper. You know, 4.2% copper in the section highlighted in the back. You know, so good grades, certainly economic grades. How that then comes together, it'll need more work.
You know, it's one of many, many exciting targets. The slide shows some of those. We've got well over 100 targets that we want to chase. It's just probably worth talking about that. That is an annual process we do to prioritize our activity in exploration. It's an active piece we're working on effectively as we speak. One of the issues we have is we have so many opportunities and priority targets, is what order do you do them in and how much do you spend on them? It's a good challenge and a good problem to have. It's something we're working through at the moment. Just to round out, early in the quarter, we did put out IP results. This time we're down closer to Hera.
Federation. Interestingly, we did four IP surveys. All of them came back with results that warrant some form of follow-up. Again, explore these opportunities, priority opportunities in the mix, and we need to think about scheduling and budgeting. Anyway, look, I recognize we've covered a lot today, and that's probably because there's been a lot going on. We will, however, now pause for questions to see if anybody needs further clarification.
Thank you. If you wish to ask a question, please press star one on your telephone and wait for your name to be announced. If you wish to cancel your request, please press star two. If you're on a speakerphone, please pick up the handset to ask your question. Your first question comes from Adam Baker with Macquarie. Please go ahead.
Hey, Andrew and team. Good quarter. Just wondering, the South Mine shaft refurb, how long is this roughly expected to take? Just wondering if you can counteract the loss in ore tons from that mine and extract ore from the North Mine during that period? In addition to this, the SAG mill reline, just wondering how long that is expected to take. Thanks.
Hi, Adam. It's Peter here. I'll answer both your questions. You've cracked our strategy on how we're going to deal with the shaft outage at the South Mine. It's about a five to 6-day changeover period. We're actually replacing the man-riding cage for the first time in the history of that shaft. There's some corrosion there. While we're doing that, we'll redeploy our workforce from the South Mine to the North Mine and focus on copper ore from the North Mine. We currently have some good stocks ahead of the mill, lead-zinc ore, and we'll finish over the next week or so. More lead-zinc will come to surface to feed the mill, the mill shouldn't be impacted materially by that particular outage. You also mentioned the SAG mill reline.
We had to defer that from March into April. That was largely around labor availability. That has been completed. Instead of our normal three-day reline program, we could only work on day shifts due to the available labor. It actually took us closer to six days. The mill came up late last week and is operating through to today. It goes on to a pause for the operator change. They're separate events, and we've had planned for those to minimize the disruption in mill feed over the course of the quarter.
Sure. Yeah, pretty short outages there. Really nothing too material for the guidance and you've stuck to guidance for FY23. That's clearly baked in there. And maybe just switching to Darce. Now that the decline is finished, how many ore tons have you got left to extract from the mine plan there?
I think the best guidance I can give you at this point of time, Adam, is look at the Production Target that we released last year, where we stand at the moment. As we flagged in the announcement, we do expect a little bit of upside there coming through from the latest program. We'll have some more to say about that when we release the updated Mineral Resource Statement or reserve statement and Production Target early in the September quarter.
Good stuff. I'll hand it on. Thanks, guys.
Thank you. Once again, if you wish to ask a quick question, please press star one on your telephone and wait for your name to be announced. Your next question comes from Michael Evans with Acova Capital. Please go ahead.
Good morning, Andy, Peter, and Martin. Thanks very much for the update today. I just wanna ask about the grades at Peak. Obviously, with the mine sequencing, something we're not privy to sort of when modeling it was sort of all worked on the reserve grades. The grade was a big driver of production at Peak in both the copper, gold and the lead zinc it looks like. You mentioned also Perseverance is getting some good grades with some positive reconciliation. I just wondering if you can give us some guidance on what you expect to see in the short term on those grades. How big is that positive reconciliation at Perseverance? Is it, I don't know, 5%, 20%?
Will that affect the June quarter, September quarter going into FY24? Should we, you know, going forward for the next few years, should we still be using the reserve grades for modeling purposes, I suppose? If not, why not? Just some more detailed color around that would be great. Thanks.
Certainly, Michael. I think addressing what should be used for modeling, what we use is our resource model reserve grade for our planning, and we update that with grade control information as that comes through. For our longer term planning, we're using resource and reserve essentially. That's a logical approach to use as well. As you're probably aware, there is a high degree of variability in the grades at Peak.
It's, in terms of gold at least, it's quite patchy, nuggety, and that does make the estimation difficult. While we did see reconciliation up to 40% above the grade control model, I would caution that that's not an ongoing event. We've also suffered negative movements or reconciliations against the grade control model. I would not be factoring that in as an ongoing positive uplift on the resource and the reserve models. Perseverance Deeps did outperform on gold, but it's also along with Kairos, the more difficult one to estimate.
We also saw some good uplift in gold grades out of Jubilee, which is a bit unexpected, particularly based on historical performance. I'll sound like a bit of a whinger, but, with the Kronos areas we're mining at the moment, some of Claros, we are mining exceptionally high grades. As much as we try and sequence those things to try and get high and low grade come together, there are times where we simply can't do that. You know, those grades have reconciled pretty well. Leads on the money is infection low. I think on that basis, using the reserve and exhaust grades going forward is appropriate.
Okay. Just remind me, the Percy Deep, how long do you expect to be mining that? How much is that in the mine plan?
We've taken most of the Perseverance deep ore there at the moment. We are going back and having a re-look at remnant areas on the basis of the high gold price we're seeing at the moment. We do have plans to do some extensional drilling beneath that. In terms of substantial stope tonnage from Perseverance deeps, that's going to fall away.
Okay. Okay, great. Just a final one while I've got you. I'm sure you've got your quarterly in front of you. If I just go to the peak data towards the back, the appendix one, detailed quarterly physicals. The peak copper, the mine grade for the gold, I'm on page 13. Have you got that, Peter? Is 1.44 and the process gold grade 3.75. Is that right? What's driving that? Does that mean next quarter will be much lower?
Um, that is-
Can you see that? Can you see it?
Yes. I should step back and say that we reconcile not on a monthly or period basis. We reconcile on campaigns. At the end of each campaign, we reconcile back. What you're seeing there in the mine grades is a combination of reconciled grades and model grades for the period, which is why they're different to the mill feed grades, which are the source of the reconciled numbers.
Is that gold grade starkly different, isn't it, on what's mined and what's processed?
Sure.
-versus the other grades?
So there's-
Yeah, okay.
There's the factors I've described. It also depends where they come from. As I said, we treat the Percy Deep ore as copper. It has significantly outperformed the grade control model.
Okay. Yeah, okay. That's great. I'll do some more thinking on that, Peter. I'll get back to you offline if I've got any more questions. Thanks very much. I'll pass it on. Thanks.
Okay.
Thank you. Your next question comes from William Thurlow with Ord Minnett. Please go ahead.
Yeah. Good day, Andrew, Martin, Peter. Thanks for taking the call and good job with the results. Appreciate the conversation on the grade profile. That was certainly one that I wanted to dig into as well. Just a basic one then. Just wanted to understand if there's a quantum for the cost associated with the Hera care and maintenance that will be incurred into the fourth quarter. Then separately, whether there's any other notable sustaining in growth CapEx items on the horizon aside from those associated with Federation?
Okay. Well, Martin here. What we're gonna see in April, we've got around AUD 7 million of costs left to come out from Hera, just in terms of trade payables and other working capital unwind. Offsetting that, we do have revenue. There's some concentrate revenue and some doré. That would be in the order of AUD 2 million-AUD 3 million. There will be another bit of unwind in that last quarter which, you know, we've factored into our plans.
In terms of ongoing costs, there is a, you know, a monthly charge, of AUD 200,000 to actually maintain the operation, to maintain the inspection routine, and to keep the operation really ready, or, you know, in a state that when we come back to mill there, that the site's been looked after. I might just hand to Peter in terms of other sustaining capital coming through this quarter.
There's not a lot of other sustaining capital coming through. DAR, as I mentioned, the decline had reached the lowest level. That's been the main source of sustaining capital at DAR, that will fall away this quarter. There are some routine maintenance related tasks at Peak that we're undertaking, but nothing major compared to what we've seen in some of the prior quarters.
Okay, wonderful. Thank you very much. I'll pass it on.
Thank you. We are showing no further questions at this time. I'll now hand back to Andrew Graham for closing remarks.
Thanks, Melanie. Look, I'll just touch on the high points again, just to leave them with you. Firstly as a management team, also as a total business of employees, we're definitely super pleased to have gone through the quarter with no recordable injuries. It's a very strong outcome for the business, and we're hoping to obviously keep that going through the next quarter and the ones thereafter. Obviously, as I touched on at the start, step change in operating performance, 26,000 ounces while sustaining of AUD 1,884, vastly better than where we had been on the half year to date, and certainly brought us definitely in line with our guidance target.
Strong cash flow, as Martin talked about, pleasingly across all three of our assets, allowing us to grow that cash balance to in excess of AUD 39 million at the end of March, putting us in a strong position as we look to finalize funding and move to development of Federation. The Federation update, Peter took us through in good detail. We are very pleased with the outcome there, particularly the fact that capital came down rather than going up despite the inflationary environment. And more pleasingly from my point of view, I think we've got a much more robust plan to develop, better operability, things like decline gradients and the layout of the figure-eight and those sorts of things will allow us to really deliver that mine with confidence.
Finally, as I mentioned on the last slide, exploration. You know, despite our real focus on cash, still investing in exploration and still getting, you know, excellent success, which again, just highlights the value of our tenement package there in Cobar. Just to wrap up, certainly very proud of the entire Aurelia team. It's an excellent set of results, and we're hoping that the entire team's proud of their achievements. Thank you for your time today.
That does conclude our conference for today. Thank you for participating. You may now disconnect.