Greetings, welcome to the Q4 and full year 2022 results conference call. During the presentation, all participants will be in a listen-only mode. Afterwards, we'll conduct a question and answer session. At that time, if you have a question, please press the one followed by the four on your telephone. If at any time during the conference you need to reach an operator, please press star zero. As a reminder, this conference is being recorded Friday, February 24, 2023. I would now like to turn the conference over to Toby Caron, Treasurer and Director of Investor Relations. Please go ahead.
Thank you, operator. Welcome to Centerra Gold's fourth quarter and full year 2022 results conference call. Please note that presentation slides are available on Centerra Gold's website to accompany each speaker's remarks. Today's call is open to all members of the investment community and media in listen-only mode. Following the formal remarks, the operator will give the instructions for asking a question, we will open the line to questions. Please note that all figures are in US dollars unless otherwise noted. Joining me on the call today are Paul Wright, Interim President and Chief Executive Officer, Paul Chawrun, Chief Operating Officer, and Darren Millman, Chief Financial Officer. I would like to caution everyone that certain statements made today may be forward-looking, and as such, are subject to known and unknown risks, which may cause our actual results to differ from those expressed or implied.
Certain of the measures we will discuss today are non-GAAP measures. Please refer to the description of non-GAAP measures in our news release and MD&A issued yesterday evening. For a more detailed discussion of material assumptions, risks and uncertainties, please refer to our news release and MD&A, along with the audited financial statements and notes, and all of our other filings, which can be found on SEDAR, EDGAR, and on the company's website at centerragold.com. Now I'll turn the call over to Paul.
Okay, thanks, Toby. Good morning, everyone, and thank you for joining our fourth quarter and full year 2022 conference call. I'd like to start the presentation by speaking to Centerra's short-term strategy as we continue to maintain our goal of establishing a stable and strong platform for future growth. This entails firstly obtaining all the regulatory approvals to restart operations at our Öksüt Mine, continuing to optimize operations and exploration at the Mount Milligan Mine, advancing the Goldfield Project with initial resource estimate mid-year 2023, followed by a feasibility study. Updating our view on the Molybdenum Business Unit, which in the future will be described as MBU, including the issuance of a pre-feasibility study detailing a potential restart of the Thompson Creek Mine, and this is to be delivered in Q3 of 2023. Moving on to slide five.
An update on the Öksüt Mine. In January 2023, we received notices of approval for the operating license extension for a period of 10 years, as well as an enlarged grazing land permit allowing for the expansion of the mine areas. These two important approvals demonstrate the continued support for both the company and the Öksüt Mine. In January 2023, the amended EIA was submitted for regulatory review. This remains in process with government authorities now reviewing our technical studies to support our EIA amendment. The mercury abatement retrofit to the ADR plant is now complete, and following regulatory approvals which are underway, we will be positioned to process gold at the rate of 35,000 oz per month.
As of December 31, 2022, there were 100,000 oz of gold stored in carbon and 200,000 oz recoverable in the inventory on the heap leach pads and in stock piles. Concerning the recent tragic earthquakes in Turkey, there were no injuries to our employees or contractors, and fortunately, no damage to the infrastructure at the mine. I will speak more to this on the next slide. Moving on from Öksüt, the company reported Q4 2022 and full year 2022 gold production of 53,000 oz and 244,000 oz respectively.
There were 189,000 oz of payable gold and 74 million lbs of copper produced by Mount Milligan in 2022, and 55,000 oz of gold produced and sold by the Öksüt Mine in Q1 2022, prior to the shutdown of operations on March 18th, 2022. In January, we announced Mount Milligan's guidance for the year, which includes gold production of 160,000 oz-170,000 oz, copper production of 60 million-70 million lbs, gold production costs of $900-$950 an oz, and all-in sustaining costs on a by-product basis of $1,075-$1,125 an ounce.
As mentioned earlier, the company continues to evaluate strategic options for the MBU, including a potential restart of the Thompson Creek Mine based on the continued strengthening of molybdenum prices and positive medium-term outlook. A pre-feasibility detailing this restart of Thompson Creek is planned for Q3 2023. At Goldfield, we continue our advancement of the project and completed approximately 50,000 meters of drilling in 2022, which will be incorporated in our planned initial resource estimate mid-year. Moving on to slide six.
In 2022, we had a number of ESG highlights, and I won't touch on all of these, but first we'd like to extend our heartfelt condolences to the people of Turkey, and particularly those who've lost loved ones due to the natural disaster. In support of the Turkish government's efforts, Centerra has mobilized emergency response teams from the Öksüt Mine to assist Turkish state emergency preparedness authorities and regional disaster response organizations. The company continues to provide equipment and material support to the ongoing recovery activities where possible. We have coordinated with one of our mining contractors to support the recovery effort with equipment and supplies, as well as trucks and crews, and continue to assist the local authorities in providing temporary housing. Moving forward in Q4 2022, Centerra successfully completed the full rollout of the Responsible Gold Mining Principles.
This has been a consistent and committed effort from many Centerra employees, especially at our Mount Milligan and Öksüt operations. We recognize and appreciate all this hard work. Additionally, the company continued to demonstrate that safety remains Centerra's top priority, having achieved 1 million hours milestone without a lost time injury at the Mount Milligan mine. I'll now pass the baton over to Paul Chawrun, who will walk through Centerra's operational highlights for the third quarter.
Thank you, Paul. On slide eight, we have the operating highlights at Mount Milligan for both the quarter and the year. 2022 was a good year for Mount Milligan. Firstly, we achieved a record annual throughput for the plant of 21.3 million tons. Additionally, the mine operated well with the total material mined at 44.3 million tons and ore mined at approximately 19.4 million tons. Cash provided and free cash flow from mine operations for 2022 were $162 million and $100 million, respectively. Gold production costs remained low at $790 per ounce in Q4, and $767 per ounce for the year.
All-in sustaining costs on a by-product basis was $629 per ounce in Q4, and $630 per ounce for the financial year of 2022. We continue to remain committed to the optimization of our life of mine plan. As mentioned in our January 2023 release, we anticipate higher gold and copper production in 2024 and 2025 than is shown in the most recent NI 43-101 technical report published last October. On the exploration front, we have completed approximately 55,000 meters of drilling since the most recent resource update. The copper head grade for the year was 0.2%, with a metal recovery at 81.9%. The gold head grade was 0.42 grams per ton, with a metal recovery at 66.9%.
The copper grades were lower than in previous years, primarily because we are starting to feed a higher proportion of the high grade gold, low grade copper ore, which is planned to continue in 2023. The staged flotation reactors have been operating since the beginning of May, with circuit optimization and full commissioning completed in the fourth quarter. The initial results have indicated elevated recoveries as planned. Moving to slide nine. Here we provide the operating results for Öksüt. As Paul previously mentioned, we received notices of approval of our operating license extension in January 2023, which is valid for 10 years, as well as the enlarged grazing land permit, allowing for the expansion of the mining areas. The amended EIA was submitted for this January for regulatory review and remains in progress.
Construction of the mercury abatement retrofit to the ADR plant is now complete and ended up being completed below the original budget of $5 million. Following regulatory approvals and restart of the ADR plant, after operations ramp up, we will be in a position to process gold at a rate of up to 35,000 oz per month. 2023 mining activities at Öksüt will be focused on the phase V wall push back to expand the Keltepe pit. As of December 31, 2022, ore processed into stored gold and carbon inventory is approximately 100,000 recoverable ounces, with an additional approximately 200,000 recoverable ounces on the heap leach pad and in stockpiles. Moving on to slide 10. We announced our 2023 operating guidance for Mount Milligan in January. Paul already provided the production highlights, but I'd like to add some additional color.
Mount Milligan's gold production for 2023 of 160,000 oz-170,000 oz, and copper production of 60-70 million lbs, is expected to be weighted higher in the second half of the year, with approximately 30%-35% of the concentrate sales expected to occur in the fourth quarter. The lower overall production in 2023 compared to 2022 is driven by mine sequencing, with the grade profile of both gold and copper slightly lower than in 2022. Mount Milligan gold production costs for the year are expected to be in the range of $900-$950 per ounce sold.
The all-in sustaining costs on a by-product basis in 2023 are expected to be in the range of $1,075-$1,125 per ounce due to the higher production costs, higher capital expenditures, and lower copper byproduct credits due to the lower copper sales estimated for 2023 when compared to 2022. Moving to slide 11. Touching briefly on the reserves and resource update, first with Mount Milligan. In October 2022, we released a new reserves estimate and life of mine plan showing an increase of 1.1 million contained ounces of gold and 260 million lbs of contained copper, which extended the mine life by four years to 2033. This update was effective December 31, 2021.
Just highlighting that the 2022 year-end reserves and resource statement applies to the depletion that occurred in the past year. Approximately 55,000 meters of drilling that was completed in 2022 will be used to update the current resource model, which will be incorporated into the 2023 mineral reserves and resources update next year. As of year-end 2022, the estimated proven and probable gold mineral reserves at Mount Milligan total 2.6 million oz of contained gold. For copper, the estimated proven and probable reserves total 902 million lbs of contained copper. On slide 12. At the Öksüt Mine, proven and probable reserves total an estimated 0.9 million oz of contained gold as of December 31st, 2022, compared to the estimated 1.1 million oz of contained gold as of year-end 2021.
A portion of the decrease of 0.2 million oz in proven and probable gold reserves can be attributed to the processing of ore this past year into an existing inventory of gold and carbon, which as we said previously, is estimated to be 100,000 oz. In addition, there are over 200,000 oz of recoverable gold contained on the heap leach pad and stockpiles. A resource update to include exploration drilling completed in 2022 is ongoing and will be included in the 2023 mineral reserves update. As you would expect, our focus in 2022 for Öksüt was to prepare and submit underlying technical studies to support the amended EIA, deliver the mercury abatement retrofit to the ADR plant on time and under budget, and prepare for the operational restart. On slide 13, we outline the reserves and resources for the MBU.
As of December 31, 2022, the total measured and indicated resources at the TCM total an estimated 177 million lbs of contained molybdenum and an estimated 166 million lbs of contained molybdenum at the Endako Mine. These have not changed since Centerra's acquisition of the Thompson Creek Metals in 2016. As previously mentioned by Paul, our current focus is on issuing a pre-feasibility on a potential restart of the Thompson Creek Mine in Q3 2023. As you all know, the Thompson Creek Mine has an overall average grade a higher overall average grade compared to Endako, and historically, the Thompson Creek Mine operated at a lower unit cost per lbs of moly. When we issue the Thompson Creek Mine pre-feasibility, we plan to provide an update on the reserves and resources. Moving on to slide 14.
A brief overview of our Moly Business Unit. There are three components. The Thompson Creek Mine, currently under care and maintenance with a restart under evaluation and a pre-feasibility currently under preparation. The Endako Mine, currently on care and maintenance with no medium-term plans for a restart, given our focus on Thompson Creek. The Langeloth Metallurgical Facility based in Pittsburgh, currently in operation. This facility purchases and processes third-party molybdenum concentrate from mines and upgrades this into molybdenum products to be sold predominantly to the U.S. steel and chemical markets. Under Thompson Creek Metals, Langeloth was fed by the Thompson Creek and Endako Mine. This facility is also a part of our focus for the pre-feasibility assessment of a potential restart of the Thompson Creek Mine. I will pass on to Darren, our Chief Financial Officer, to discuss the financial highlights.
Thanks, Paul, and good morning, all. For those following on the slide deck, I'll initially be speaking to slide 16. Centerra recorded $208 million in net revenue during the quarter, consisting of the Mount Milligan mine and the Molybdenum Business Unit. No revenue was recorded at the Öksüt Mine. At the Mount Milligan mine, gross sales and copper sales were $67 million and $53 million respectively. In the quarter, Mount Milligan sold 49,444 oz of gold and 15.4 million lbs of copper. The Öksüt Mine has no recorded sales or production in the quarter. We continue to hold the stored gold and carbon inventory of 100,000 recoverable ounces.
The cost associated with the Öksüt stored carbon inventory is approximately $450 all-in sustaining costs per ounce, which has been capitalized as a current asset within the inventory. Importantly, this quarter, we are highlighting our additional 200,000 oz in heap leach pad and stockpiles that will be subsequently processed once we return to operational status at the Öksüt Mine. At the Molybdenum Business Unit, approximately 4 million lbs of molybdenum was sold, generating $87 million with an average market price in the quarter of $21.49 per lbs of molybdenum.
During the quarter, the Molybdenum Business Unit generated $8.6 million in free cash flow with a focused effort on reducing inventory levels. During the quarter, the Mount Milligan mine operations average gold price realized was $1,352 per ounce and $3.43 per lbs of copper. This incorporates the existing stream arrangements over the mine. Cash used in operating activities by operations was approximately $10 million for the quarter and generated $25 million free cash flow, sorry, $25 million free cash flow deficit in the quarter. As noted in the MD&A, the Mount Milligan mine generated $26 million positive free cash flow and $16 million in free cash flow for the quarter. For the year, the Mount Milligan mine generated over $100 million in free cash flow.
As noted by Paul, another strong operational performance at Mount Milligan mine, with record annual throughput at the mill. Given no sales occurred at the Öksüt Mine in the quarter, with operations continuing, that we had $16 million used from treasury. This is a reduction from the previous quarter of $23 million as a result of reduction in activities at the site. The net loss from continued operation was $130.1 million in the quarter, with $13.7 million in adjusted net loss for quarter. The earnings in the quarter attributable to operations were $30 million contributed from the Mount Milligan mine, $3.4 million loss from the Öksüt Mine, and $5 million loss from the Molybdenum Business Unit. For the quarter, there were three adjusting items.
The Kemess impairment loss of $138 million net of tax, deferred income tax recovery of $14 million resulting from the underlying tax base adjustment of the Öksüt Mine, and $4.4 million non-cash gain de-recognition of past employee health plan at the Langeloth Facility. This was in connection with the spanning of the union workforce with no future commitments on the plan. On the Kemess impairment loss, as the company and its technical team are focused on the delivery of the pre-feasibility and the potential restart of the Thompson Creek Mine in Q3 of 2023, together with the delivery of the initial resource of the Goldfield Project by mid-year, there has been no resources, financial or otherwise, committed to the Kemess project.
Given this was a similar status at the end of 2021, this has resulted in an impairment indicator under IFRS 16, with a subsequent impairment assessment occurring in Q4, and reclassification of the Kemess project as a non-core asset. The impairment consisted of two components, a value per institute gold equivalent ounces and a valuation of capital equipment at site. If you refer to note seven of financial statement for further detail. The all-in sustaining cost reported for the quarter was relatively high compared to the previous quarter. This was primarily driven by lower copper production in Q4 and thus resulting in lower copper credits. Paul has explained this earlier with the ore presented to the mill in Q4 being high gold grade with low copper grade.
I would highlight also in 2022, all our operating cost metrics were either within guidance or performed better than the 2022 guidance range previously provided. I'm now speaking to slide 17. For the full year, Centerra produced 244,000 oz of gold and 74 million lbs of copper. Given the inventory levels at Öksüt Mine at time of restart and regional operational performance, we are well-placed as we move into 2023. In Q4, we returned $23 million to shareholders in dividends and share buybacks, with a total of $60 million in returns to shareholders in 2022. In early February, we initiated changes to the streamline the corporate structure and reduce workforce levels at regional and corporate office, with an average, with an overall 20% re-reduction in head count at these locations.
The company has exited 2022 with a cash balance of $532 million and over $900 million in liquidity. Given our strong financial position, the board has declared a quarterly dividend of $0.07 per share. Those are my closing comments. With that, I'll pass it to Paul just to finish up.
Okay, Noah, thank you very much, Darren and Paul. At this stage, operator, I think we'll open up for questions, please.
Thank you. Certainly. Ladies and gentlemen, on the phone lines, if you wish to register for a question, please press the one followed by the four on your telephone. You will hear a 3-tone prompt to acknowledge your request. If your question has been answered and you would like to withdraw your registration, you can press one three. Once again, ladies and gentlemen, that is one four to ask a question on the phone line. One moment, please. Once again, ladies and gentlemen on the phone lines, you can press one four on your telephone if you have a question. All right. At this moment, I'm showing no questions on the phone lines.
All right. Well, thank you very much, all for attending. We look forward to speaking on our next quarterly call. Enjoy your weekend. Thank you, operator.
Thank you. Ladies and gentlemen, that does conclude today's call. We thank you for your participation and ask that you please disconnect your lines. Have a good day.