About 100 riot-equipped Alabama state troopers used tear gas yesterday to disperse a band of more than 500 striking United Mine Worker members at Mentone, Ala., and arrested 30 persons, most on weapons charges.

The latest confrontation in the coalfields came as the strike by about 160,000 UMW members was entering its eighth week.

Alabama state police said the windshields in three patrol cars were smashed by UMW members, some of whom were armed with shotguns, handguns and ax handles. There were no injuries.

"We got them mostly on weapons charges - carrying guns without licenses - and for public intoxication," said a state police spokesman, adding the miners apparently were headed for some non-union mines in northwest Alabama.

The troopers "told us to get the hell out of there," said William Manderson, 23, of McCalla, Ala. "They just gave us three minutes to clear out and it wasn't enough time. There was no liquor. We had a few guns but they were in cases." UMW District 20 president Charles Fuller said he would lodge a complaint with the Alabama Department of Public Safety.

Meanwhile, contract talks aimed at ending the strike moved to a critical stage in Washington as union and industry negotiators appeared to be narrowing their differences over major issues blocking a settlement.

Top-level industry executives whose authority would be needed for major decisions were told to remain in the city, an indication that bargaining has intensified. And a late-night bargaining session was scheduled last night, the first in several weeks. "They're not fooling around," said a source familiar with the talks.

Sources said "bits and pieces" of a new contract have begun to fall into place, but cautioned that some "road blocks" remain.