Muh. Isnin Asri and Selfina Gala 2026. Nickel Extraction From Solid Waste From The Nickel Smelting Industry Through An Environmentally Friendly Organic Acid Leaching Process. International Journal of Health Engineering and Technology. 4, 6 (Mar. 2026). DOI:https://doi.org/10.55227/ijhet.v4i6.611.