The Sprott-backed company said it had received its licence to install, which had been anticipated last year, permitting it to start construction.
"Amarillo is one step closer to becoming a gold producer," CEO Mike Mutchler said.
The company said the licence was delivered 10 days after the state's governor announced his support for the project at a public meeting on mining investments in Goias, and a week after Amarillo signed an agreement to build a dedicated power line from Porangatu to its flagship Mara Rosa project.
Posse is expected to cost US$145 million and produce an average annual 84,000 ounces of gold over 10 years, according to a 2020 feasibility study which put the after-tax NPV5 at $183 million and IRR at 25%.
Amarillo had recruited two mine builders with experience in Brazil to its board of directors last year and was working on financing negotiations.
It had raised US$57.2 million at 30c per share in August, with Eric Sprott increasing his stake to 17.9% on a non-diluted basis.
The company also has the earlier-stage Lavras do Sul project in Brazil's Rio Grande do Sul.
Amarillo shares (TSXV: AGC) closed up 3.5% to C29.5c on Friday, capitalising it at $112.7 million (US$88.3 million).
