Commissioned by Euromines from Project Blue, this 57-page study documents the magnesia industry’s strategic significance to European decarbonisation, finding very limited ability to substitute dead-burned or fused magnesia in refractory applications and no substitute for the refractories themselves. EU electric arc furnace capacity is projected to grow to 35.7 megatonnes per year by 2030, all of which will require more magnesia-carbon refractories than the blast furnaces they replace; making secure magnesia supply a direct precondition of green steel at scale. The study was commissioned as part of a coordinated lobbying effort to have magnesite and magnesia re-listed as EU critical raw materials ahead of the next CRM review cycle.