Some 150 workers and their supporters marched through Holyhead to the Anglesey Aluminium smelter, last Saturday.
The plant stopped production on 9 September, throwing 400 workers out of work.
The mood was one of sombre anger, summed up by Unite union senior steward Gwilym Owen, who said, “In hindsight the companies [Rio Tinto and Kaiser Aluminium] played it very cleverly.
“They always held out hope that a deal could be reached. What they were really doing was spinning it out so that the shareholders could take the profit right to the last minute.”
Last minute bids to get the firm to take a £48 million state subsidy and keep the factory open failed.
Rio Tinto made £1.6 million profit from the plant in the last six months.