Industrial wastewater is a significant threat to aquatic and environmental habitats. The harsh chemicals and heavy metal ions present in industrial wastewater heavily impact the equilibrium of nature. This study uses red mud (RM), an industrial waste byproduct, as a metal adsorbent over thermal processing. A recent study examined the effects of calcined red mud and colloidal nano-silica (CNS) composite on metal extraction efficiency. This study measured the concentration of Cd, Pb, As, and Cu remaining in the wastewater solution after exposure to the ternary blended red mud CNS cement samples over time using atomic absorption spectroscopy. The Red mud cement CNS mortar samples are kept in the wastewater over a period of time, and the heavy metal ion concentration in the solution before and after the exposure is measured. The results showed that a combination of ternary blended mortar with cement replacement by 1.5% CNS and 15% red mud showed the highest adsorption. Calcination significantly enhanced the metal extraction efficiency of red mud. The metal extraction efficiency order for the proposed composites is in the order of Cr > Cd > Pb > Cu. The X-ray diffraction patterns of heavy metal ions loaded samples revealed changes in silicate crystallinity and an alumina phase transition, which shows the affinity of the proposed ternary blend mortar to the heavy metal ions. Therefore, the red mud CNS nano composites can alter the mineral phases, impacting its functionality as a metal adsorbent. Hence, red mud CNS cement composites can be used as a metal extraction agent for wastewater purification.