The ship is expected to depart early next week bound for China.
About 25,000 t of product is being shipped.
That shipment will provide both revenue and vital learnings to enable future shipments to carry 30,000t of product.
The product has been bought by Royal Advance.
Elmore managing director David Medelawitz said the loading of the first shipment closed the first chapter of the Peko story and marked the beginning of the company's path as a business focused on cash generation.
"Everyone involved in preparing for this ship has been on a steep learning curve from optimising the plant and loading the trains through to building the stockpile in the port shed," Medelawitz said.
"These invaluable lessons will move Elmore forward with the confidence that the infrastructure and the Peko project can deliver what we have set out to achieve."
Elmore is aiming to achieve a vessel a month once the Peko ramp-up is completed, which is targeted for the end of the March quarter.
The final steps to achieve the target of monthly 30,000t shipments are ramping up rail manning and completing the spare parts inventory on site to stabilise production.