The company has delivered a 21.6% increase to life-of-mine revenue with an expanded 24-year life, a 24% better internal rate of return and 9.4% jump in post-tax net present value - all while reducing capital costs 6% and keeping opex in the lowest industry quartile.
Revenue is now US$1.44 billion, NPV10 is $197 million, IRR is 119% and capex has fallen to $27.8 million.
Forecast production remains at 40,000 tonnes per annum over an extra four years, with costs at $347/t free-on-board from the port of Mtwara, and with weighted average basket price of $1515/t, margins remain over $1000/t despite the fact it has tempered its sales assumptions.
Executive director Allan Mulligan said the project was sufficiently robust it would be largely immune to operating and capital cost risks.
"This mine has been designed to withstand potential start-up and ongoing risks. It continues to show outstanding economics with a payback period of less than two years. These factors make the project attractive to potential funding partners and investors," he said.
The revised DFS contains a revised and remodelled mining plan that will reduce annual mill feed from 280,000tpa to an average 230,000tpa but with an increased head grade, while by stockpiling lower grade ore creating "a near capital-free" expansion opportunity that will be assessed during optimisation studies yet to be undertaken.
Walkabout has defined a number of opportunities to increase production in the future, but is yet to do any real work on them.
Commissioning could take place between 9-12 months after the final investment decision. It is looking at a mix of debt and equity funding.
Walkabout recently increased the proven and probable ore reserve by 10% to 5.5 million tonnes, with the total graphite content up 22% to 987,000t and the life of mine grade up 11% to 17.9% TGC.
It was the first company to be awarded a mining licence since Tanzania changed its legislation,
Shares in the junior were up 7.4% in morning trade to A14.5c, valuing the company at $44 million. It is approaching a 52-week high of 17.5c.