Eco-Efficient Nickel: Heap Leaching as a Game-Changer for Indonesia’s Nickel IndustryAchmad Fauzi Trinanda, Ridho Lestari, Muhamad Ichlas Juliansyah, Rizky Aisyah Septi Maharani and Natasha Kisti NugrahaE3S Web Conf., 693 (2026) 02003DOI: https://doi.org/10.1051/e3sconf/202669302003