The latter NPV estimate uses recent reported spot prices of US$80,000/t for lithium hydroxide and lithium carbonate, while the base case uses $18,533/t and $17,305/t respectively.
An exchange rate of 65c per Australian dollar was in the scoping work.
The development's internal rate of return is 22% in the base case scenario and 44% using the higher pricing.
Avenira is looking to initially develop a 10,000t per annum operation, and then use the cashflow to add two further production trains that will take output to 30,000tpa. The latter production rate has a pre-production capital cost of A$527 million.
Avenira owns the Wonarah direct-ship-ore phosphate asset in NT that is currently the subject of a near-completed feasibility study.
With an enterprise value of less than $16 million, Avenira's ambitions are to develop Wonarah, the LFP venture, and a thermal phosphoric acid plant that's capable of supplying feedstock to the LFP plant and for sales into other specialty chemical markets.
Shares in the Brett Clark-led Avenira were unchanged at 1.4c in morning trade, capitalising the company at $17.4 million.
Avenira had $1.4 million cash at the end of December.