The most common and most likely answer to this crossword clue is the 8 letter word REFINERY
I've seen this crossword clue in The Times
R
E
F
I
N
E
R
Y
More clues leading to the result REFINERY
- Engineers passionate about new treatment plant
- Concerning to find showy adornments in place practising purification
- Polish railway leads to plant
- Extremely rare, expensive clothes in industrial plant
- Plant soldier’s decorations
- Engineers with special gear maybe in industrial installation
- Where things get strained, learning religion with glitzy trappings
- Engineer gets best clothes for chemical plant
- About to get showiest clothes in factory?
- Best dress given to engineers for industrial plant
Buddy explains!

The straight part
We know that "Factory" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case factory = refinery.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does REFINERY mean?
REFINERY noun- A building, or a mass of machinery, used to produce refined products such as sugar, oil, or metals.