Ironbark Biochar: A Novel and Efficient Adsorbent for Gold Recovery

A study explored ironbark biochar as an effective, low-cost adsorbent for gold recovery, achieving 858 mg/g adsorption from aqueous solutions. Advanced modeling favored Artificial Neural Networks for predicting outcomes, with physisorption and electrostatic attraction identified as key mechanisms.

May 7, 2024

1–2 minutes

Mele, et al (2024) Investigation of gold adsorption by ironbark biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More using response surface methodology and artificial neural network modelling. *Journal of Cleaner Production.* https://doi.org/10.1016/j.jclepro.2024.142317

In recent research, a new type of biochar derived from ironbark has demonstrated remarkable effectiveness in adsorbing gold from aqueous solutions, reaching an impressive capacity of 858 mg/g under optimal conditions. This study explores the potential of using ironbark biochar as a low-cost, high-efficiency adsorbent for reclaiming gold from waste streams such as tailings and industrial wastewater.

Ironbark biochar is produced through pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More at 500°C, resulting in a material with a high surface area of 493.79 m²/g. Its high porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More makes it ideal for capturing gold from water, following the Langmuir model of monolayer adsorption. This indicates that the gold attaches in a single layer across the biochar’s surface, highlighting the efficiency of the adsorption process.

The research utilized advanced modeling techniques to optimize and predict the adsorption process. An Artificial Neural Network (ANN) model, enhanced by the Salp Swarm Algorithm (SSA), provided more accurate predictions of gold adsorption than the traditional Response Surface Methodology (RSM), indicating a better fit with the experimental data.

The primary mechanisms identified for gold adsorption were physisorption and electrostatic attraction, suggesting that the biochar attracts gold particles through physical bonding and charge-based attraction. These findings underscore the biochar’s potential for industrial applications, particularly in recovering valuable metals from waste.

Overall, the study not only confirms the high adsorption capacity of ironbark biochar but also contributes to the field by offering a sustainable method for gold recovery. This could significantly reduce environmental impact and provide a cost-effective alternative to more traditional methods of gold extraction from industrial waste.