The phrase "as a separate article" is correct and usable in written English.
It can be used when referring to a distinct piece of writing or publication that is independent from other content.
Example: "The findings will be discussed in detail as a separate article to provide a comprehensive analysis."
Alternatives: "in a distinct article" or "as an individual piece".
I've pulled that out as a separate article, but here are some of the other main talking points.
And if the length of that proved too clunky for inclusion in the article, the explanation could have been published as a separate article near the main one.
The electrochemical characterization results will be published as a separate article.
The example of whale evolution is such an outstanding case of macroevolution, however, and has made so much recent progress with amazing new specimens that we have set it aside as a separate article (Thewissen, this volume).
Each chapter is written as a separate article and there is little to link one chapter with any other.
As reported in a separate article, on the same day that New York's finest were setting dragnets for peaceful cyclists, a truck killed an 86-year-old woman trying to cross 14th Street.
Last year, on the Daily Kos, Margaret Pless called him out for hosting an infamous cyberbullying hub called Kiwi Farms, which, as she noted in a separate article for New York, "specializes in harassing people they perceive as being mentally ill or sexually deviant in some way".
If an event was reported more than once in the same newspaper, we counted it every time it was reported, so long as it was in a separate article.
As I'll describe in a separate article, the methodological choices made by pollsters may have something to do with it; Mr. Obama's bounce has been much more noticeable in polls that use live interviewers and that call cellphones.
But as The NYT notes in a separate article, under Obama's plan, rich is defined rather broadly.
The Denver Post described the organization as a censorship watchdog organization, and a separate article from the same newspaper called it a left-of-center politically aligned group, which advocated for both intellectual freedom and artistic freedom.
