A REVIEW OF GOLD BIORECOVERY FROM ELECTRONIC WASTES
Electronic equipment's revolutionary use gained some negative impacts, such as the massive amounts of electronic waste every year. Waste Electrical and Electronic Waste, also known as e-wastes, has great potential because it contains valuable metals, especially gold. The gold content in the...
Saved in:
| Main Author: | |
|---|---|
| Format: | Final Project |
| Language: | Indonesia |
| Subjects: | |
| Online Access: | https://digilib.itb.ac.id/gdl/view/51434 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | Electronic equipment's revolutionary use gained some negative impacts, such as the
massive amounts of electronic waste every year. Waste Electrical and Electronic
Waste, also known as e-wastes, has great potential because it contains valuable metals,
especially gold. The gold content in the e-wastes, especially in printed circuit boards
(PCB), is higher than landfill gold mining. Therefore, gold recycling can reduce waste
and utilize the economic value of e-wastes. Also, the environmentally friendly method
of gold recycling through the biohydrometallurgical process continues to advance.
Biohydrometallurgical studies will answer the challenge of reducing hazardous waste
in conventional processes. The gold bioleaching study aims to learn further about
several objects, namely the microorganisms involved in the leaching process, the
leaching mechanisms, the leaching parameters, and the overall processes.
Simultaneously, copper bioleaching was also studied because copper is the base metal
in e-wastes. Copper can consume reagents during gold leaching and reduce gold purity,
which is undesirable in the gold leaching process.
This final project's writing process began by looking for related papers and books
containing the following keywords: bioleaching, printed circuit board (PCB), e-wastes,
and recycling. The research for data and information sources is limited to the literature
that only discusses PCB and the copper and gold bioleaching process. After that, the
next process is reading, concluding literature sources, and writing the literature studies
results in this final project.
Based on the literature study, copper bioleaching from PCB can use several
microorganisms, namely autotrophic bacteria (iron and sulfur-oxidizing bacteria),
heterotrophic bacteria, and fungi. In general, the extraction of copper happened because
of several metal mobilization mechanisms, namely acidolysis, complexolysis, and
redoxolysis. The copper bioleaching process can be carried out at optimum
temperatures (20-45 °C) to high temperatures (45-122 °C) according to the type of
microorganism used in the process. After that, the gold is extracted by cyanide
producing bacteria to form gold cyanide complexes. Generally, bioleaching of copper
and gold using cyanogenic bacteria occurs at 30 °C and pH 7-10.5. Bioleaching of
copper using non-cyanogenic bacteria is carried out at pH 1-4. The highest recovery
recorded in the copper bioleaching (99.99%) was obtained using a mixed culture of A.
thiooxidans + A. ferrooxidans. In comparison, the highest recovery in gold bioleaching
(73.17%) was obtained by using a mixed culture of P. aeruginosa + C. violaceum. |
|---|