Leandro Raggio
Analyst · BTG Pactual
Thank you, Gabriel. Good morning to all, and thank you for joining us today to discuss the quarterly results of Compañía de Minas Buenaventura. On Slide 2, it's our cautionary statement, important information that I encourage you to read because of the current circumstances.
Today, we will be discussing our performance for the first quarter 2024, highlighting key achievements and strategies moving forward. After the presentation, we will be available for our Q&A session, where our team will be happy to answer your questions.
The next slide, please. I would like to highlight a few key areas that contribute to our strong first quarter '24 results. Our EBITDA from direct operations for the first quarter has increased 83% compared to the previous year, primarily driven by improved performance at El Brocal and Yumpag. This is also reflected in a higher EBITDA margin of 38% compared to 28% from the previous year.
First quarter '24 operating income reached $46.9 million compared to the last year's of $12.6 million. Copper production increasing 26% year-over-year, driven by steady exploitation rate at El Brocal, which surpassed 10,500 tons per day in the underground mine.
Silver production reached 3.1 million ounces, a significant increase compared to the 1.3 million ounces produced last year for the same period. From this, 1.5 million ounces come from Uchucchacua and Yumpag where we got approval of the final mining operating permit earlier than expected.
Ore production decreased 4% year-over-year, reaching 36,500 ounces since we are now mining lower rates of Orcopampa and Tambomayo. We are pleased to inform that the dividends from Cerro Verde were received on April 26, last Friday. These dividends will strengthen our overall financial strength. Buenaventura's CapEx in first quarter 2024 totaled $58 million, which includes $38 million allocated to the San Gabriel Project.
Our cash position reached $174 million with a total debt of $699 million. We continued deleveraging the company reaching a net debt EBITDA ratio of 1.78x lowest in the 2 years -- in 2 years and within our target range.
Moving on to our cost structure in Slide 4, please. First quarter '24 all-in sustaining costs have reduced by 58% year-over-year. This reduction is primarily attributed to the copper production at El Brocal and silver contribution from Yumpag. However, it is important to mention that part of the Yumpag costs have been considered to be CapEx. Normalized all-in sustaining cost should be around USD 3,600 per ton of copper, still below than the previous year.
Moving on the cost applicable to sales. As you can see, the prioritization of copper at El Brocal and the ramp-up in the underground mine is translating into a continuous cost reduction trend. Silver CAS has decreased year-over-year, primarily driven by higher contribution of Uchucchacua and Yumpag silver ounces. Normalized CAS, including Yumpag cost is expected to be between $17 and $18 per ounce.
Gold CAS has decreased year-over-year and even quarter-over-quarter, primarily driven by higher grades and lower mill at El Brocal underground mines despite lower grades at Tambomayo and Orcopampa.
On the next slide, we will be presenting the free cash flow generation. During the first quarter of 2024, we reduced our cash position by $46 million, primarily due to the intensive capital expenditures campaign, which includes San Gabriel. The EBITDA to free cash flow reconciliation is explained by the following breakdown of inflows and outlets.
El Brocal, Yumpag and Orcopampa have been the main contributors for the first quarter 2024. As we have mentioned before, Buenaventura is going through a growth phase with an intensive CapEx related to San Gabriel. The previously reported dividends from San Gabriel will be registered in the second quarter of 2024.
Moving on to Slide 6. In the next year, Buenaventura will be focusing most of its efforts in the San Gabriel project. On this slide, you can see the projects, the new latest progress reaching a 47% overall progress by the first quarter 2024, primarily driven by the full installation and operational concrete plan. The key milestone we are closely monitoring for the next quarter is the start of the mine development tunneling, and the start of the SAG mill assembly.
On the next slide, we are showing the competition of the definite campsite that is fully operational since [indiscernible]. We have more than 2,000 sleeping beds installed considering the definite and organic concept, water treatment plants, offices and dining areas are fully operational.
On the next slide, we are showing the progress -- the processing platform. Here is the milling area where we are planning to start the SAG mill assembly during the next quarter. And on the next slide, you can see the installation of the thickeners.
Finally, I would like to finish the presentation with a couple of closing remarks. First, encouraging production resource at Yumpag are a clear reflection of our success delivering mining products. With final mine impairment secured we are now focusing on achieving a stable and efficient production grade at 1,000 tons per day. This will be reflected in a significant increase in revenues in the following quarter. Excellent performance at El Brocal in line with plan to reach 11 tons per day by the end of the year, supported by a positive trend in copper price.
Third, we are proud to announce that we have achieved a significant progress at San Gabriel project, now standing at an impressive 47% overall completion. On track as we aim of our first gold bar by the second half of 2025. Currently, we are assessing the project CapEx to ensure an accurate total cost while define opportunities to optimize the cost structure.
We continue our efforts to transform our mining operation into assets with plus 10 years of life of mine and focus on optimization them to achieve greater cost efficiency.
Thank you for your attention, and I will hand the call back to the operator to open the line for question. Operator, please go ahead.