PFS calculations

Im new to this so not 100% sure if i got the methodology correct or if i have missed something??
I have been playing been playing with a few scenarios for potential PFS numbers. One scenario was the MNS model, 15 Years lifetime, 240,000 tonnes per year and so on.

Potential revenue using VRC latest flake distribution results

	Column 1	Column 2	Column 3	Column 4
0	Grade	Quantity	Basket Price	Revenue
1	Super Jumbo 21%	50,400	$    2,500.00	$ 126,000,000.00
2	Jumbo 36%	86,400	$    1,600.00	$ 138,240,000.00
3	Large 24%	57,600	$    1,400.00	$    80,640,000.00
4	Medium 6%	14,400	$    1,050.00	$    15,120,000.00
5	Fine 5%	12,000	$   500.00	$ 6,000,000.00
6	Amorphous 8%	19,200	$   300.00	$ 5,760,000.00
7		240,000		$ 371,760,000.00
8
9			15 Years Revenue	$  5,576,400,000.00

Cost using MNS capex, i have increased our processing costs by $100 from $560.

	Column 1	Column 2	Column 3
0	Pre Production Capex	$   270,000,000.00
1	Capacity  (t)	240,000	1 Year
2	Liftime Capacity (t)	3,600,000	15 Years
3	Life Time (years)	15
4	Processing Costs	$   660.00	t
5		$   158,400,000.00	1 Year
6		$   2,376,000,000.00	15 Years
7		$   2,646,000,000.00	Total Project Cost

NPV = $2,930,400,000.00
Am i missing something or is it that simple?