New mine project posted on Mine Developments – Chirundu
Uranium mineralization is of the style referred to as 'sandstone-type uranium deposits' which have been the source of a significant proportion of uranium ore production globally.
The pre-feasibility study is based on uranium ores being mined initially from the Njame deposit only, with mining and heap leaching to commence at the Gwabe site once Njame has been exhausted.
All mining will be from open pits, with ore stacked as a series of cells on a single-lined leach pad, and waste will be stored on a waste dump. Comminution tests indicate that the ore is very soft and is not abrasive and is amenable to mining by continuous surface mining equipment at costs equal to or less than drill and blast.
Overburden removal may be by surface miner or a combination of ripping and drill and blast. On completion of operations, leach heaps will be neutralized and rehabilitated with top-soil cover.
Processing of the ores by heap leaching will use sulphuric acid irrigation supplemented with an oxidant (hydrogen peroxide, manganese dioxide or ferric sulphate), with solutions supplied from double-lined ponds. Pregnant leach solutions will be passed through an ion-exchange column where the uranium is adsorbed onto resin beads prior to elution, precipitation and ultimately packaging. All elution, precipitation and packaging will be carried out at the Njame Central Processing Facility, including the processing of loaded resin delivered from the Gwabe Remote Ion-Exchange operation.
Uranium ore will be delivered to the leach pads at a rate of approximately 2.25Mt per year to produce, on average, approximately 1.3 Mlb per year of U3O8 over an initial mine life of just over 5 years.
Hydrogeological studies have indicated that suitable water is locally available and that a small production bore-field near the mine should provide sufficient process make-up water for the operation.
Negotiations for a Power Supply and Power Connection Agreement have commenced with local utility ZESCO. Diesel electricity generation will be evaluated as an alternative power option during the Bankable Feasibility Study
Operating costs will be in the range of $30 to $40 per pound recovered U3O8. Based on these operating cost estimates, the project has good