The grade increase will be even better than your projections. BTW "Grade for 2020 was 2.33% and for 2021 we expect a 10%" you meant 2.33 grams ton. If it was 2.33% Karora would rival Tesla for mkt cap ;-)
On grade the the nickel is equivalent to over $1,000 a ton or 30 grams gold a ton. It is much richer than the gold ore. I have written several blog posts on Karora and will copy in a recent comment did on this:
"Karora says: The new nickel zone named 50C is said to have the potential to represent a repeat of the historic Beta Zone, which has produced over 32,000 tonnes of nickel metal to date. The 50C Nickel Trough is located 140 meters from existing development and remains open to the south, Karora said.
Drilling intersected gold mineralization above and below the 50C trough and suggests that the Beta Hunt gold mineralized system extends for over 3.5 kilometers of strike from the northern end of the A Zone.
That is 1/2 a billion usd dollars worth of nickel 32,000 x 2,200 x 7.40 a pound = $520 MILLION. 11% nickel = 31 grams of gold over 4.6 meters.
It is interesting they say " repeat of the historic Beta Zone, which has produced over 32,000 tonnes of nickel metal to date.", they are thinking it is huge deposit.
And this is better than the apparent "That is 1/2 a billion usd dollars worth of nickel 32,000 x 2,200 x 7.40 a pound = $520 MILLION. 11% nickel = 31 grams of gold over 4.6 meters." because no mill is necessary. That half a billion can be added on top of current production. And BTW $520 million usd is more than entire mkt cap of Karora."
The key here is not only is the nickel super profitable, the BHP nickel concentrator is next door to Beta-Hunt mine and was built for Beta-Hunt a decades long major nickel producer which recently has been converted to gold. So they can mine all the nickel they want to with no mill constraints. For a really wild idea they could go 100% nickel at Beta and continue to 100% fill HGO mill (Karoras gold mill) from just HGO mines. If they do so that would double? Karora rev and skyrocket their profits.
Even without nickel their grade will go up more than 10% as at Beta the Larkin Zone which they have started mining has double the gold grade of 2020 mining and HGO grade will go up to with 2 very high grade open pits coming online in 2021.
Cheers