The updated resource estimate for the Idaho project follows a decision to substantially the existing modify stope design and mine plan execution as part of a bankable feasibility study, with the change to the approach taken by prior owners expected to increase cobalt grade and reduce dilution once mining begins.
Measured and indicated resources are now 5.24 million tonnes at 0.44% cobalt, 0.69% copper, and 0.53 grams per tonne gold for 50 million pounds cobalt, 80Mlb copper and 89,000 ounces gold.
Inferred resources add a further 12Mlb cobalt, 15Mlb copper and 23,000oz gold.
Last year the company drilled 19 diamond holes for 3125m to support its BFS.
The results allowed Jervois to make changes to cell size and block rotation, and reduce the cut-off grade from 0.2% to 0.15%, although the mineralised envelope at ICO is significant and represents upside if the cobalt price rises.
Reserves for Idaho's Ram deposit will be updated once the BFS is completed, by the end of March.
Jervois believes Ram is one of the highest-grade cobalt deposits in the world, with its location in a stable, tier one jurisdiction giving it additional cachet.
Jervois wants to revive the partially constructed mine with construction and financing planned later this year and first production planned by the end of 2021, ramping up to 1200 tons per day.
In Uganda, the first assays from the Kilembe phase one drilling of 17 diamond holes for 1905m to test a number of anomalies returns hits such as 9.9m at 1.37gpt gold from 29m, including 0.45m at 9.9gpt and 0.1% copper from 24m and 1.9m at 3.59gpt from 37m.
The company's work has defined a 6km-long mineralised zone of which only 1.5km has been tested.
Drilling has resumed at Kilembe.
The company also completed a second phase of drilling at Bujagali with 10 holes for 1740m to test the Waragi prospect within a 20km-long copper-cobalt with early assays retuning 1m at 0.2% cobalt from 13.4m and 1.5m at 0.23% cobalt from 13.5m.
Jervois said the Ugandan work continued to be promising.
Shares in the junior were steady at A22.5c, valuing the company at $144 million.
It has traded between 17.5-30c over the past year.