"With unemployment standing at over 40% the planned retrenchments kill off hope and a possibility of a life of dignity as mercilessly as a R1 bullet," he told reporters in Johannesburg.
"We are preparing all our members for this mother of all struggles."
Earlier this month, Amcu rejected the pay offers made by gold mining companies.
According to Fin24, AngloGold and Sibanye proposed on July 30 to raise monthly pay for entry-level workers by R1,000 annually for the next three years starting on July 1. Harmony offered a R500 increase. Basic pay is currently about R5 800. Living-out allowances will be raised by R100 in the first year from R2,000 now.
Mathunjwa on Thursday described the offers as "crumbs".
"They [mineworkers] are clear, they are fighting for R12,500, partly out of respect for their fallen brothers and partly because anything less condemns them to lives of misery," he said.
"It is tragic that for those that survived the bullets of Marikana, they now face being fired as part of the retrenchment wave that is gripping many sectors of our economy with mining at the centre."
Source: News24
