Firefighters were called to an incident at Farington Waste Recovery Park.
Three fire engines attended the waste treatment facility, in Sustainability Way, Bamber Bridge, near Preston, at around 8.40pm on Monday.
Four officers wearing breathing apparatus tackled the fire with a hose reel.
The 15-strong team then used two thermal imaging cameras to make sure there were no other pockets of fire.
A Lancashire Fire and Rescue Service spokesman said there was slight damage caused by heat and fire to an industrial processing machine and severe damage caused by fire to half a tonne of recycling products.
The site is run by Global Renewables, which has a £2bn, 25-year private finance initiative (PFI) agreement with Lancashire County Council and Blackpool Council to process the household waste of the 1.4m people in Lancashire.
A spokesman for the company said: “At 8.30pm smouldering waste was noticed in one of our trommels.
“We implemented our emergency procedures, contacted the fire brigade, ensured the site was safe and evacuated the premises.
“The fire brigade arrived on site at 8.58pm and having ensured that there was no danger, they began to leave at 10.20pm.
“The site was handed back and normal operations resumed at 11.15pm.
“At no point was there any danger to our neighbours, our site or our employees.”