London-based capital market firm Tamesis Partners published a detailed research note on Adriatic on Monday, calling Rupice "one of the highest grade-assets in the world".

"The grade of 12.5% equivalent zinc for the whole project and 18.3% for Rupice alone (equivalent to 9gpt in gold terms) means the mine is going to be one of the highest margin assets in the world," said an extract from the note.

"Cash costs in zinc equivalent are -151c/lb. Looking at the universe of producing operations, we calculate Rupice as the seventh highest margin globally based on the first three years of production, and the highest base metals project. On a life of mine basis Adriatic would be the 16th highest margin project and the sixth highest base metals project."

The report came out as Adriatic released early results from phase two metallurgical testing.

Recovery rates were 89.7% for copper, 69.3% for gold, 92.1% for silver, 75.8% for zinc and 84.9% for lead - compared with the company's preliminary metallurgical results released in September 2019, which put recovery rates at 82.7% for copper, 66.7% for gold, 92.6% for silver, 81.7% for zinc and 90.4% for lead.

Adriatic said the zinc recovery "was slightly lower than attained with the average grade sample due to the higher zinc concentrate grade produced. Optimisation work is expected to improve that recovery to 80-85% as obtained in the previous average grade test work".

"Although this program of test work has only just begun, and I am hopeful of further progress that can be incorporated into our feasibility work recently commenced by Ausenco," Adriatic CEO Paul Cronin said.

Adriatic plans to release its prefeasibility study "somewhere around May", with a bankable feasibility study to follow towards the end of 2020.

The company dual-listed in London last month.

Sandfire Resources holds 16% of Adriatic.

Adriatic shares last traded at A$1.85, up 200% over the past year and 17.5% so far this year.