The report says its net present value today is US$15bn using a 10% discount rate.
This figure rises to US$27bn once the mine is up and running. The after-tax internal rate of return is put at 26%.
The operation has the potential to generate underlying earnings (EBITDA) of US$1-3bn a year, depending on volumes and price.
The cash margins on the business are put at 70-85%, while operating costs are expected to be in the order of US$37.20 a tonne.
The plan is for the York mine to initially produce 10mln tonnes of polyhalite fertiliser a year, though there is the capacity to double output.
The cost to deliver the 10mln tonnes a year is put at US$3.56bn, with the financing done in two tranches.
Talks with potential funders are “well developed”, the company said.
First production could occur in the next five years with the company hitting the 10mln tonnes per year figure by 2023.
It has been a long haul to get to this pivotal stage in the development of Sirius and its project, which is located in North Yorkshire's National Park, not far from Scarborough.
The granting of mining and transport licences last year were major milestones that paved the way for construction, which could begin later this year.
Managing director Chris Fraser said: "The business that is created from this project will sit as a world leader in the fertiliser industry based here in the UK.
“It is expected to have a low operating cost structure, high margins and a very long asset life in one of the most business friendly, stable and dynamic economies in the world.
"In delivering this project we can create thousands of jobs in North Yorkshire and Teesside, deliver billions of pounds of investment to the UK and put the country at the forefront of the multi-nutrient fertiliser industry.
"The DFS represents the blueprint to bring this global fertiliser business into large-scale production and successfully delivers on the core strategic vision of the company to become a major low cost producer of multi-nutrient fertilisers.
"Work is advancing with our financing partners globally to bring together the pieces of the initial financing of this project.
“This process is expected to take a number of months but certain parts of the early construction activity, such as highways upgrades, are commencing soon to facilitate an efficient start of the project.”
The York operation will be the first new potash mine in the UK for 40 years and will use a deep shaft to access the thickest and highest grade polyhalite ore reserve in the world.
It will also involve the development of an underground mineral transport system from the mine to a proposed new materials handling facility at Wilton on Teesside.
Polyhalite is a naturally occurring mineral containing four of the six nutrients required for plant growth - potassium, sulphur, magnesium and calcium.