Efficient Gold Recovery from Cyanide Solution Using Magnetic Activated Carbon.
Jinsong Xia1, Harshit Mahandra1, Ahmad Ghahreman1
1Hydrometallurgy and Environment Laboratory, Robert M. Buchan Department of Mining, Queen's University, 25 Union Street, Kingston, Ontario K7L 3N6, Canada.
ACS Applied Materials & Interfaces
|October 4, 2021
Summary
Magnetic activated carbon offers an efficient solution for gold recovery from cyanide solutions. This novel material demonstrates rapid gold adsorption and easy magnetic separation, overcoming limitations of traditional activated carbon in mining.
Area of Science:
- Materials Science
- Chemical Engineering
- Mining Engineering
Background:
- Activated carbon is a widely used material for gold recovery in the mining industry due to its high surface area and affinity for aurocyanide ions.
- Challenges with conventional activated carbon include difficulties in separating it from slurries and slow adsorption rates associated with coarse particle sizes.
Purpose of the Study:
- To develop a simple, sustainable, and efficient method for gold recovery from cyanide solutions using magnetic activated carbon.
- To address the separation challenges and improve adsorption kinetics compared to traditional activated carbon.
Main Methods:
- Synthesis of magnetic activated carbon using a solvothermal method.
- Characterization of magnetic properties (magnetism) and surface area (BET analysis).
- Evaluation of gold recovery efficiency, adsorption kinetics, and isotherms in cyanide solutions.
- Testing of magnetic activated carbon reusability through adsorption-desorption cycles.
Main Results:
- The synthesized magnetic activated carbon exhibited strong magnetism (44.57 emu/g) and a specific surface area of 249.7 m²/g.
- Achieved 99.1% gold recovery efficiency from a 10 mg/L cyanide solution within 5 hours, significantly faster than commercial granular activated carbon.
- Easy separation of magnetic activated carbon from the solution using an external magnet was demonstrated.
- The material showed good reusability in adsorption-desorption tests.
Conclusions:
- Magnetic activated carbon provides a highly efficient and easily separable alternative for gold recovery from cyanide solutions.
- The developed material overcomes key limitations of conventional activated carbon, offering faster adsorption rates and simplified downstream processing.
- The study highlights the potential of magnetic activated carbon for sustainable and economical gold mining operations.
Related Concept Videos
00:56Extraction: Advanced Methods
577
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
577
01:06Coagulation
465
Colloidal solids are solid particles suspended in solution. They are usually negatively charged, attracting a compact primary layer of positively charged ions, which attract more counterions to form an electrical double layer. Electrostatic repulsion between the charged double layers prevents the particles from colliding, stabilizing the colloids. These solids are often undesirable because they can contain toxins that are difficult to remove. Coagulation is a technique that helps aggregate and...
465