My quoted figures included the allowance for concentrate make up, I was not using total Fe/waste numbers. So 2625T crusher feed will provide 1013T of concentrate. This is publicly available information directly from GBG!!!
However it is a simple mathematical manipulation to calculate. I will use 100 tonnes as a standard.
100 tonnes @ crusher feed @ 36% Fe is 36 tonnes Fe entering the process.
36 tonnes of Fe leaving the process @ 68% is ~53 tonnes of concentrate (or 53% of process feed).
That is the pure numbers, GBG are suggesting 38.5% (1013/2625) comes out the tail end therefore suggesting plenty of Fe is lost in the processing circuit.
ie. 0.68%*38.5= 26.18 tonnes Fe (total)
26.18/36= 72.7% therefore GBG have guided the market to say they will lose 27% of the Fe in the circuit. This is very important!!!!!! There are two critical terms when talking about processing ores (well there are lots but two important ones here), product grade and recovery rate. Your grade is what % of valuable material is contained within your product (ie 68% Fe) and recovery rate is how much of your valuable constituent going into the process comes out the back end. Have you heard over hydromining gold tailings???? this is because with old mines the grade was good.....but recovery rate was terrible!!!
You do not need RDD to confirm what the crusher feed needs to be to achieve nameplate unless you know exactly what the processing plant is doing. It can be used as a rule of thumb. 63000T per day to the crusher with the plant performing as expected using GBGs numbers will get us to nameplate.
There are probably 100 other questions I could ask RDD on the topic given the information above but without him being in the mill/flotation/process circuit he may not be able to answer.
I have always given RDDs information several reviews. The numbers he was stating quite often didn't make true sense (as many quickly claimed bullshit and shouted him down without further thought) and I have therefore thought of other potential meanings. To me all of RDDs suggestions have been around tailings and how the process was working and he was saying concentrate grade (but it could not have been this)? I think he was being told information that was correct but could mean many different things. I think RDD was being told recovery rate as opposed to ore grade. You can theoretically achieve a recovery rate of 100% ie. all Fe being fed into the circuit comes out the back end in concentrate but this would not be economically viable. For magnetite the maximum theoretical grade is ~72.34% (close to the recovery suggested above!! confusing!!). No one ever suggested that this could recovery rate that RDD was talking about....people just picked a point and shot him down, the guy works on the hill...he is not a process engineer or process tech. Everything is second hand and you know what happens with Chinese whispers!! The max theoretical % grade and recovery rate are unfortunately very similar which I am guessing led to confusion.
Now after all these incoherent ramblings early on a Sunday morning let me just make one change to the numbers.
Let's say the recovery rate was 75% and grade 68%....what happens here.
100*36%=36 *75% /68% =39.71 tonnes of concentrate for 100 tonnes of feed (1.2 tonnes improvement)
what would the crusher feed need to be to achieve nameplate?
1013/39.71% * 24 hrs = 61,220 T per day....1780 T less than above.
You can play with numbers all day....if they get higher than expected recovery rates it is excellent as long as concentrate grade is maintained. This is all just opinionated speculation until the company reports on how the darn plant is working!!! I am certainly not suggesting that this is what is happening because......I have no information to base it on....just an alternative view point with some theoretical numbers!
After all this we get to delve into the financials, the debt, the TO spot, interest rates, FX rates, royalties and tax (Gindaldan has that all pretty figured out). Anyways, I patiently await the announcement on how processing facility is operating.
GBG Price at posting:
15.5¢ Sentiment: Buy Disclosure: Held