A blast that partially destroyed the roof of a large grain store was caused by a rare "dust explosion", a fire service has said.
The explosion at Tilbury Port on 3 July was described as "like a bomb going off" with flames 75m (246ft) high.
Essex Fire and Rescue said the cause of the fire was recorded as "accidental" and no-one was injured.
"Dust explosions like this are very rare but occur if the dust reaches a flammable temperature," it said.
The port said it had commenced "a phased start-up of operations at the terminal" last week.
Fire crews remained on site for 20 days extinguishing fires in the grain stores and preventing damage to the site.
A metal dust explosion in 2014 caused a blast that tore through a plant in eastern China, killing 75 people.
And 14 people died in an explosion at a sugar refinery, caused by exploding sugar dust, in the US state of Georgia in 2008.
Peter Ward, commercial director of the Port of Tilbury, said grain handling and storage had carried on at the port shortly after the fire.
He said the phased return to full operations was "a credit to our port team and their fantastic effort to restore the facility during these challenging times".
The grain terminal at Tilbury opened in 1969 and is the UK's largest, according to the port's owners.