- To participate in the 911Metallurgist Forums, be sure to JOIN & LOGIN
- Use Add New Topic to ask a New Question/Discussion about Hydrometallurgy.
- OR Select a Topic that Interests you.
- Use Add Reply = to Reply/Participate in a Topic/Discussion (most frequent).
Using Add Reply allows you to Attach Images or PDF files and provide a more complete input. - Use Add Comment = to comment on someone else’s Reply in an already active Topic/Discussion.
Non-Refractory Gold Ore Processing (5 replies)
I suggest you review your history of gold metallurgy. Heap leaching was practiced as vat leaching in 1910 or earlier. Gravity concentration has been done for centuries. Sorption technology was practiced in Australia during WWI. There was work done on characterizing the properties of activated carbon for gold and silver cyanide in the 1920's. Zadra and Chapman developed elution processes in the early 1050's. Chapman developed a process using powdered activated carbon in the 1930 and used the AARL process in 1949 on granular carbon. Only it was not called AARL until 1997.
Tails & waste today are ore for tomorrow.
It is simple- gold reserves are getting smaller, mines are getting deeper and more expensive to run the gold price goes up due to world effects- commodity shortages/ stockpiling by major countries unrest/cold war/oil prices/ austerity etc. and as the gold price goes up it becomes more opportune to treat low grade easy access ores or deposits like tailings /old heap leach pads etc.- hence the quote or saying, who by the way really spiced up the discussion with the history revealed on the subject.
I've got nice news: In Canada start up new gold project with low grade (0.8 g/t!)- "Detour Lake mine". It design capacity is 55ktpd, achieved - 63ktpd! Design recovery- 91.2%. It was nice design solutions:
Before SAG mill installed secondary crusher!
Leaching time – 32-48 hours!
Grinding ore pass to pre-leaching in thickener!
I think this is beginning new (next) generation!
It’s old hat stuff. South Africa to be exact through Anglo Gold Ashanti at the time operated processing plants on tailings since 1976 followed by Durban Roodepoort Deep in the early 1980's the Rand Mines stable at Crown Mines Johannesburg.
DRD now owns the ERGO plant which started in its original form in 1976 and today processes 45000 tons a day at a grade lower than 0.4g/ton Au and they make money! Order of magnitude is the key.
I don't believe that it is new at all; it's rather a question of people doing better research, using best modern day technology, highly skilled staff who knows their business and willing to put their money where their mouths are.
I’ve read about ERGO plant. ERGO technology is known as flotation with ultrafine grinding concentrate. But comparison will be incorrect, because both plants have different initial product (ore and tails). For correct comparison may be take other plant - Paracatu plant.
Let’s talk about new technology conception. I think it will have following:
Specific power consumption at comminution must be less 10kW/t.
Leaching time must 80-200 hours.
Specific water consumption must 0.3-0.5 m3/t.
Recovery 80-90%.
Don't CIL, CIP, RIL, RIP processes.
Don't thickeners &filters.
What do you think?
Please join and login to participate and leave a comment.
Over time I have seen two generations in the gold industry for non-refractory ore. The first began in the 70s of this past century. Its name - gravity technology and applied to ore with minimum grade 2-3 g/t. The second began at 0s 21century. It name - heap leaching technology and applied to ore with minimum grade 1-1.5 g/t . Now need to work gold ore with grade 0.5-0.7 g/t and capacity 70-100 Mty. Will be new generation?