Good morning. My name is Chris, and I'll be your conference operator today. At this time, I'd like to welcome everyone to the Natural Resource Partners LP. Fourth Quarter and Full Year 2022 earnings conference call. All lines have been placed on mute to prevent any background noise. After the speaker's remarks, there will be a question-and-answer session. If you'd like to ask a question during this time, simply press Star, then the number one on your telephone keypad. To withdraw your question, please re-press Star one. Thank you. Tiffany Sammis, Manager of Investor Relations. You may begin.
Thank you. Good morning, welcome to the Natural Resource Partners L.P. Fourth Quarter 2022 conference call. Today's call is being webcast, a replay will be available on our website. Joining me today are Craig Nunez, President and Chief Operating Officer, Chris Zolas, Chief Financial Officer, and Kevin Craig, Executive Vice President. Some of our comments today may include forward-looking statements reflecting NRP's views about future events. These matters involve risks and uncertainties that could cause our actual results to materially differ from our forward-looking statements. These risks are discussed in NRP's Form 10-K and other Securities and Exchange Commission filings. We undertake no obligation to revise or update publicly any forward-looking statements for any reason. Our comments today also include non-GAAP financial measures. Additional details and reconciliations to the most directly comparable GAAP measures are included in our fourth quarter press release, which can be found on our website.
I would like to remind everyone that we do not intend to discuss the operations or outlook for any particular coal lessee or detailed market fundamentals. I refer you to Sisecam Resources LP public disclosures and commentary for specific questions regarding our Soda Ash segment. I would like to turn the call over to Craig Nunez, our President and Chief Operating Officer.
Thank you, Tiffany. Good morning, everyone. I would like to begin by thanking our employees for their outstanding contributions, executing our strategy to delever and de-risk the partnership. I'd also like to thank our equity investors, bondholders, and banks for your enduring support. A special word of appreciation is owed to our board of directors for its wise guidance and counsel. When we embarked on our new strategy seven years ago, the partnership was in a precarious financial position with almost $1.5 billion of debt, representing more than two-thirds of our capital structure. Our bonds were trading at $0.65 on the dollar. Our free cash flow was negative. Our future looked bleak. We responded by exercising extraordinary financial discipline to aggressively cut costs, eliminate capital expenditures, and sell off underperforming assets with an incessant focus on delevering and de-risking the capital structure.
Today, I'm proud to say that the partnership is dramatically healthier and financially stronger than it was seven years ago. We have right-sized the business from four business segments down to two, both of which now earn returns on capital well in excess of their cost of capital. Our operating and interest expenses are each more than 70% lower than they were when we began. Our free cash flow, which had been negative, exceeded a quarter of a billion dollars in 2022, a record for the partnership. Our debt, which had been almost $1.5 billion, had declined more than 80% to $169 million at year-end. The financial profile of today's NRP is so remarkably improved from that of seven years ago that it would be hardly recognizable to anyone who hadn't followed the transformation.
I am especially proud that these results have been achieved without the use of sly legal maneuvers, debt forgiveness, or bankruptcy. Let it be known that NRP keeps its promises, pays its debts, and does exactly what it says it will do. We have come a long way, but there is still more work to be done. Our goal remains to retire all permanent debt, redeem all of our 12% convertible preferred equity, and eliminate all outstanding warrants. Taken together, these commitments currently total approximately $465 million. If our business continues to generate free cash flow at the current run rate, I hope to reach this goal within 2 to 2.5 years. Once these obligations are eliminated, free cash flow available for common unit holders will increase, most likely in dramatic fashion.
With that, I'd like to summarize our recent operating performance. NRP generated $268 million of free cash flow in 2022, which is the best financial performance in the partnership's history. We paid off $269 million of debt during the year, and our leverage ratio now stands at 0.5 times. We paid out $34 million of common unit holder distributions during the year, which was a 52% increase over the previous year. We have now paid common distributions in every quarter in the 20 years since the partnership went public, except for one quarter during the depths of uncertainty in the COVID-19 pandemic.
I would also like to note that in 2022, we made noteworthy progress on our carbon neutral initiatives with the signing of our first two carbon sequestration leases with both Denbury and Oxy, and our first geothermal energy lease in Texas. While the timing and success of these ventures is uncertain. The assets underlying these leases represent approximately 800 million metric tons of subsurface CO₂ storage capacity and have the potential to generate 15 megawatts of green geothermal energy. Our Mineral Rights segment delivered exceptionally strong performance in 2022, with revenues up over 65% from the previous year. Metallurgical coal prices reached historical highs and were the primary driver of strong segment performance. Numerous factors continue to provide support for met pricing as the post-COVID recovery continues.
Supply chain disruptions, labor shortages, and years of underinvestment in new coal production capacity continue to undermine producers' ability to bring new production online to meet demand. While met prices have pulled back from the peaks reached last year, we continue to believe met prices will remain well supported for the foreseeable future. Thermal coal prices also reached record highs in 2022, have declined significantly in recent months due to unusually warm weather in Europe and North America. Thermal prices traded at a premium to met for much of last year, even pulling lower-quality met coal into thermal markets at times. That situation no longer exists as thermal coal now sells at significant discounts to met. While we do not see thermal prices rebounding to last year's record levels, many of the factors that provided support to prices over the last year still exist.
Boycotts of Russian coal continue to force European buyers to source coal from other regions, including the U.S. Operators will continue to be burdened by labor shortages, pressure from governments, regulators, activists, and capital providers, which will limit ability to increase thermal production to meet demand. It appears that China is beginning to relax its 3-year ban on Australian coal imports with the recent approvals for several Chinese companies to buy Australian coal. Additional demand from a Chinese economy emerging from its zero-COVID policy should also provide additional support for prices. We expect these factors to keep thermal prices elevated relative to historical levels for the foreseeable future. Turning to our soda ash investment. Global soda ash demand has continued to grow due to China's emergence from its zero-COVID policy, the continuing secular growth in renewable energy, the electrification of the global auto fleet, and urbanization.
Soda ash supply, however, currently remains constrained as new capacity has not kept pace with demand growth. Constrained supplies combined with energy and raw material input cost inflation drove soda ash prices to record levels in most parts of the world during 2022. Strong sales prices coupled with Sisecam Wyoming's position as one of the world's low-cost producers of soda ash resulted in a 170% increase in Sisecam Wyoming's operating profit compared to the prior year. We continue to believe that the long-term outlook for soda ash remains favorable. Lastly, I'd like to note that a holder of our 12% convertible preferred equity issued a conversion notice to us on forty-seven and a half million of preferred units last month. We have the option of settling preferred unit conversion notices by either paying cash or issuing common units.
After considering our financial position, liquidity, and comparing the market value of NRP common units to our estimate of intrinsic value, our board of directors decided to settle this conversion notice with the payment of forty-seven and a half million of cash instead of issuing NRP common units. The outstanding amount of our convertible preferred equity decreased from $250 million to $202.5 million. With that, I'll turn the call over to Chris to cover our financial results.
Thank you, Craig. During the fourth quarter, we generated $69 million of operating cash flow and $63 million of net income. For the full year, we generated $267 million of operating cash flow and $268 million of net income, both more than twice the prior year full-year amounts. These significant increases were driven by high net coal prices and increased cash distributions received from our soda ash business. Moving to our segment results. Our Mineral Rights segment generated $68 million of operating cash flow and $63 million of net income in the fourth quarter, and $263 million of operating cash flow and $267 million of net income for the full year of 2022.
Metallurgical coal made up 65% of our coal royalty revenues during the fourth quarter of 2022 and 70% of our coal royalty revenues for the full year of 2022. Compared to the prior quarter, both segment free cash flow and net income were relatively flat. Compared to the prior full year, segment free cash flow increased $104 million and net income improved $124 million. You may recall, we began to see the benefits of higher metallurgical pricing at the end of the third quarter of 2021.
While the Mineral Rights segment fourth quarter of 2022 results were relatively flat compared to the prior year quarter, there was a significant increase in free cash flow year-over-year, driven by a full year of strong met coal prices in 2022. Shifting to our Soda Ash business Segment. Net income in the fourth quarter and full year of 2022 was $16 million and $60 million respectively. These amounts were $5 million and $38 million higher compared to the prior year periods, both primarily driven by higher international Soda Ash sales prices. Free cash flow from our Soda Ash business Segment in the fourth quarter and full year of 2022 improved $3 million and $34 million respectively as compared to the prior year periods.
These free cash flow increases were a result of the improved segment business performance in 2022 and Sisecam Wyoming reinstating their regular quarterly cash distribution in the fourth quarter of 2021. Moving to our Corporate and Financing segment. In 2022, we utilized the increased cash flow generated from our strong business performance to make great strides in de-risking, de-leveraging partnership's capital structure. In the third quarter of 2022, we refinanced and extended our credit facility, increasing its capacity to $130 million and extending its maturity date to 2027. This re-refinancing enabled us to fully retire all of the outstanding $300 million 9.125% Senior Notes due 2025, utilizing cash on hand and borrowings on our new credit facility.
With the Senior Notes fully repaid, this will save over $25 million of cash from lower annual interest expense. 2022's strong business performance, combined with our significant debt reduction, resulted in our leverage ratio dropping from 2.7x at the end of 2021 to 0.5x at the end of 2022. Our total Corporate and Financing segment costs for the fourth quarter and full year of 2022 were relatively flat compared to the prior year periods. During 2022, we recognized loss on early extinguishment of debt associated with the retirement of our $300 million 2025 Senior Notes and increased incentive compensation costs because of our significantly improved 2022 business performance.
These cost increases were offset by lower interest expense because of less debt outstanding in 2022, resulting in a relatively flat overall Corporate and Financing segment cost. Moving to 2023, the de-risking of our capital structure has continued with the cash redemption of $47.5 million of our outstanding preferred units. These preferred units were redeemed at par, of the originally issued $250 million of preferred units, $202.5 million now remain. Regarding distributions, in November of 2022 and February of 2023, the partnership paid a quarterly distribution of $0.75 per common unit and a quarterly cash distribution of $7.5 million to our preferred unitholders.
Today, we announced a one-time special cash distribution of $2.43 per common unit to help unitholders cover their 2022 tax liability associated with owning our common units. With that, I'll turn the call back over to the operator for questions.
Thank you. As a reminder, if you would like to ask a question, please press star then one on your telephone keypad. We'll pause for just a moment to compile the Q&A roster. Again, that's star one if you'd like to ask a question. It appears that we have no questions. I'll turn it over to Craig Nunez for any closing comments.
Thank you. The future remains uncertain. Commodity prices remain volatile, and financial markets are going to remain unpredictable. However, due to the significant accomplishments of our team over the past seven years, along with our improved business performance, positive outlook, and most importantly, our stronger financial position, we believe we are now well prepared for future challenges. We are steadfast in our commitment to pay off all permanent debt, redeem all preferred equity, and settle all warrants in order to maximize long-term free cash flow available for common unitholders. We remain confident this path is the best approach to maximizing long-term common unitholder value. Thank you for participating in our call today, and thank you for your continued support of NRP.
Ladies and gentlemen, this concludes today's conference call. Thank you for participating. You may now disconnect.