TXRogers wrote:
BmBillyBass wrote: Could someone tell this genius he also needs to know how much it costs to sort. And I dont mean just the cost of the sorter. I mean excavationg, crushing to size, clearing, sorting, loading, transporting to mill, and everything else Ive forgotten.
Jeez
@jimbowie Does the cost of using ore sorting outweigh the benefits? Using hypothetical numbers the answer is yes. From a QH interview, we learned that it costs around $25 a ton Australian to process ore at the mill. To calculate whether ore sorting saves money, you need to know the price of gold, the mass reduction, the head grade of the ore, and the gpt lost during ore sorting. In the following calculation, I assume that the savings from reduced tons of ore hauled to the mill are negated by the cost of loading and processing ore through the sorters. Assume ore with a head grade of 2gpt is sorted and results in a mass pull of 50% with a recovery of 95% of the gold. You'd get 50% savings on processing the ore through the mill or $12.50 Australian. You'd lose 5% of the gold which is .1 grams. .1 grams currently goes for $9 in Australia. So you would save $3.50 a ton overall ($12 less $9). Doesn't sound like much but the savings over a year would be over $5 million. If you could reduce the mass pull to 20% with a recovery of 98% of the gold then the savings per ton would be $16.40 ($20 processing savings less $3,60 in lost gold). Yearly savings would be around $25 million. Let's hope they can achieve good numbers from ore sorting. Billy FishFace
Well Billy, sometimes a "genius" is defined not by what he knows, but what he asks.
I also am curious about sorting. However, I think what is more critical at this point is not the sorting process in its pure definition (at least not directly).
I am more curious about the impact of sorting in context with the necessary mill modifications to handle the varying %Mass Pull characteristics resulting from the input ore concentrate. From low grade refractory ore to higher grade sorted ore options.. After all, this is a Pilbara Novo mill now, and no longer a local MOY mill.
%Mass Pull as the % of the material (mass) sent to flotation a “pulled/floated” into the concentrate. This number needs to be as small as possible to consider the flotation to be more selective.
Obviously, if 100% of the feed is sent to concentrate, a 100% recovery is achieved (without concentration). It is erroneous to believe that the goal is to put as much metal in as little a concentrate mass as possible. Pulling more mass is a complicated process. There are mill mechanical implications as larger mass often cannot be handled by pumps or process cells for lack of volumes.
For example, base metals plants/concentrators, a stage process that yields more than 20% mass pull, is likely to encounter problems and plant processing failures. It does not concentrate enough. Optimum results are obtained at 10% to 15% mass pull.
The proper/ideal gold reagent needs to be selective, and must aim at putting the correct metal in the correct concentrate to maximize specific output and revenues. Which brings us back to the indirect implications of sorting.
Novo is intimate with the technical aspects of the MOY mill. They have been studying it for many months and “kicking the tires” before deciding to purchase the operation. We also know that Novo is quickly in the process of implementing modifications to this mill.
You can bet your bottom dollar that the modifications (ie, gravity circuit, water supply, etc.) are all designed to placing the gold in the correct concentrate to maximize specific output and revenue for the mill. And not simplistically attempting to maximize the head grades to excessive %Mass Pull levels that would result in lower outputs or mill component damage.
So, I am not only curious on the efficiency of sorting itself. I am also very curious on the how sorted ore concentrate will be mixed with lower grade ore so that the optimal gold reagent and %Mass Pull is safely maximized and is maintained continuously. Investors should consider this aspect very seriously. Because it is something that MOY could not facilitate and did not pursue.
I do not know the intimate details of the Novo mill modifications currently underway. But by every indication they are premeditated, well thought out, and targeting a much more comprehensive “Pilbara solution”.
A solution that will maximize mill efficiency and output for varying types of available ore with varying grades. And ironically, sorted ore may actually constitute an "%Mass Pull enhancement" that brings positive economic viability to ore that was once considered marginal.
Anyways ..... the properties of genius, idiot savant, inquisitive dopes - none are really required to be a successful investor. Not our job.
Tx