The big spend to upgrade operations at Dalrymple Bay also coincides with a lift in terminal charges.
The ASX-listed company will spend $165m on replacing a shiploader and $116m on replacing a reclaimer at the Dalrymple Bay terminal, with both projects expected to begin in 2023.
The spend will likely mean a jobs boost for Mackay, though a company spokesman could not confirm how many.
“We are currently progressing tender processes for these new projects and will be better placed to confirm the number of local jobs once those processes are complete,” the spokesman said.
Shiploaders and reclaimers are used to transfer bulk material off and onto ships.
DBI CEO Anthony Timbrell said the spend would ensure “terminal capacity” for its users.
Major miners in the Bowen Basin export coal through Dalrymple Bay, including Glencore and Anglo American.
DBI has also updated its terminal infrastructure charge, or the cost it imposes on coal firms to use its facilities, for 2023-2024.
It will charge $3.45 per tonne this year, an 8.7 per cent increase on the 2022-23 charge.
DBI announced a 10-year pricing agreement with users in 2022 with the base charge indexed on an annual basis in line with inflation.
Dalrymple Bay is the world’s largest metallurgical coal export facility with a capacity of 84m tonnes per annum.
It is owned by the Queensland government but has been leased to DBI.
The company is also branching out into green energy.
In 2022, it announced funding for a set of feasibility studies to determine the viability of a hydrogen supply chain in the Mackay region and the ability of the Dalrymple Bay to transition to handling green energy exports.
A spokesman confirmed this week the studies were ongoing.
The company booked a net profit of $69m across 2022.
Year-to-date, its shares are up 5.7 per cent to sit at $2.58 for a market capitalisation of $1.28bn.