Thanks, Gary. At our last earnings call, we discussed how we shut down our operations in Mexico in the first quarter and intend to sell them. Now we have presented our Mexico operations as a discontinued operation in all reporting periods in our financials and first quarter 10-Q. It's easier to see and discuss the results of our continuing operations. So to that end, let's first talk about some financial highlights from our continuing operations.
Sales for the first quarter increased 28% over last year's first quarter. Gross profit dollars in the first quarter more than doubled last year's first quarter, and we had income from continuing operations for the first quarter of this year of $86,000. Cash provided by the operating activities of our continuing operations in the first quarter was $350,000, and cash provided by our continuing operations in total was $327,000. Also, we sold more antimony and zeolite in the first quarter than in last year's first quarter.
Where do we go from here? At a high level, grow revenue profitably and increase cash flow, as I've said in the past. This is a management team and Board and employees that all contribute and do not stop. We all share ideas and challenge each other to improve ourselves and our company.
What are we doing specifically? First, we're adding experienced personnel to an already strong group. A good example of this is that our zeolite plant in Idaho. We added experienced personnel to an already strong group at BRZ and are changing and strengthening our mining and processing of zeolite. It is costing some money, but it's paying off. The amount of zeolite sold in the first quarter increased over last year's first quarter. And we're meeting the delivery timing requested by our customers more now than in the past.
Second, we have a Board that is seasoned and experienced and very involved with our company. They have connections on potential mineral reserves that have not yet been claimed and mineral companies that are potentially for sale. They also have government connections and are trying to position our company to sell product to the U.S. government. I don't know if these initiatives will be realized and unfortunately, we can't discuss the details yet. However, be assured, we are a team that continues to challenge the status quo and does not stop.
Let's review our financials in a bit more detail. First, cash flow. So cash flow from the operating activities of our continuing operations improved by $1.4 million in the first quarter compared to last year's first quarter. This improvement was primarily due to improved working capital management with better collections on receivables, better inventory management and maintaining a low amount due on royalties.
Cash flow used by financing activities of our continuing operations improved by $800,000 in the first quarter compared to 2023. Primarily, that was due to a payment of a dividend of almost $800,000 in the first quarter of last year to our Series D preferred stockholders. Overall, as Gary mentioned, cash and cash equivalents increased in the first quarter of 2024. And our cash balance at March 31, 2024 was $11.9 million.
Next, let's take a look at the income statement. As I said earlier, sales from continuing operations increased 28%, mainly on higher demand for antimony and zeolite. You can see this increase in product sales affecting our inventory levels a bit. Zeolite inventory is about 20% lower in the quarter and antimony inventory is about 50% lower in the quarter. We have sourced the majority of our antimony ore over the years for our plant in Montana from a company headquartered in Canada, and we have a few new sources of antimony ore that we are currently evaluating. Also, we had some sales at the end of the first quarter, and receivables are noticeably higher at March 31, 2024, but these receivables have since been collected.
Gross profit, as I said, more than doubled in the first quarter versus last year. Our antimony gross profit was very strong in the first quarter. It's tough to predict that this will continue. However, I can say that one variable that helps our gross profit is the increasing antimony market price, which is currently around $7.44, which is a 40% increase since the end of 2023. We have not seen this high of an antimony market price in over 5 years. Our zeolite business struggled at the beginning of 2024 with higher repairs and maintenance costs and other inefficient costs, but we finished the quarter strong, with older machinery, equipment, vehicles that were not maintained over the years, and this makes it difficult to predict future levels of these types of costs. However, we have been working and are continuing to work to prevent issues with our assets in the near term that caused these types of costs and downtime, while at the same time, working on a solid plan for the future. We'll keep both these streams progressing and share more details on future webcasts.
Last, operating expenses increased about $577,000 for the first quarter compared to last year's first quarter. About $200,000 of this expense is higher than it should be going forward. This expense mainly relates to a portion of the stock compensation that was front loaded in the first quarter of 2024 and audit and legal fees that were incurred later in the year last year when we were filing our 10-K. That's it for now.
Gary, I'll pass it back to you.