Mrs Scargill, 52, was among five demonstrators arrested at 5am near the home of Richard Budge, the owner of the RJB Mining company, at Wiseton in Nottinghamshire, and accused of causing a breach of the peace.
She later returned to the scene of her original arrest, about half a mile from Mr Budge's property, where she was again taken into custody just before 10am.
Being used to confined spaces - she spent five days on an underground protest with three other women at Parkside colliery near St Helens, Lancashire, in 1993 - Mrs Scargill was unperturbed by her experience.
"I've not been charged with anything, and I don't know why the police arrested me on either occasion," she said. "The officers who questioned me said their operation was called Operation Babysit, but being arrested twice makes me wonder whether it should be Operation Nappy Rash."
Mrs Scargill was there as a member of the No Open Cast campaign group protesting against RJB's policies. According to one of Mrs Scargill's colleagues, the protesters planned to dig up Mr Budge's garden "to show what an open cast site looks like on his premises".
An RJB spokesman said the company had to meet stringent guidelines before it was granted permission to mine any site. He said No Open Cast had approached the company last week, demanding to be allowed to hand in a petition at Mr Budge's home.
"We refused to grant them that but offered to meet them at the company's offices or at another suitable venue," said the spokesman. "The next thing we know, they are off out trying to dig up the garden first thing in the morning."
He dismissed the group's claims that opencast mining was unnecessary and said opencast coal was crucial to RJB's ability to provide the quality of coal required by Britain's power stations. Matthew Brace