The Jadar deposit, discovered in 2004 in western Serbia, is a concentration of lithium and boron in a mineral new to science named jadarite, LiNaSiB3O7(OH). The deposit is located in a valley with flat-lying farmland covering a surface area of 3.0 km by 2.5km. Known lithium and borate mineralisation lies at depths from 100 m to 720 m below surface.

The mineralization is hosted in a lacustrine sedimentary sequence of Miocene age dominated by calcareous claystones, siltstones, sandstones and clastic rocks (about 400 m to 500 m thick). The sequence dips to the north at between 0 and 25 degrees or more, but typically between 5 and 10 degrees, and it includes several thin tuff beds that provide valuable marker horizons for stratigraphic correlation. Miocene sediments lay unconformable on a basement of Cretaceous age.

The deposit includes three types of mineralization occurring as stratiform lenses of variable thickness, and hosted in gently dipping sequence of mainly fine-grained sediments that is dissected by faults:
o Jadarite LiNaSiB3O7(OH) mineralization, new to science and so far unique to this deposit; occurs within a stratiform sedimentary lacustrine sequence with sub-horizontal beds of jadarite as rounded grains, nodules, or concretions generally in the range 1 mm to 10 mm in a siltstone / mudstone matrix. Jadarite is mainly concentrated in three gently dipping tabular zones known as the Upper, Middle and Lower Jadarite Zones (UJZ, MJZ and LJZ).
o Sodium borates, mainly in the form of Ezcurrite - Na4B10O17·7H2O, but also as Kernite - Na2B4O7·4H2O, and Borax - Na2B4O7·10H2O, occurs as lenses that are interbedded with jadarite-bearing siltstones and mudstones, present mainly enclosed or adjacent to the LJZ with a more restricted areal distribution.
o Gypsum occurs as layers of gypsiferous sandstone mixed with carbonate and crosscut by fibrous selenite gypsum veinlets; it is concentrated in the upper part of the sequence in the transition from lacustrine to brackish conditions (sub economic).

The genesis of the jadarite and borate mineralisation is conceptual at this stage:
o Jadarite and borate beds are thought to have formed at or near the water– sediment interphase in the sediments from hydrothermal fluids entering the basin.
o The jadarite and borate mineralisation has similarities to other deep water borate environments (i.e. Furnace Creek Fm. in US).

Jadarite bearing sediments are affected by sedimentary processes during deposition, including dewatering, sliding, slumping and extensional / compressional fractures associated with these events. Mineralisation is affected by normal and reverse fractures post lithification with limited remobilisation of jadarite and other borate minerals.

Significant mineralogical changes in the vertical are controlled by the geochemical evolution of the basin and mineralising events over time, and by the basin scale graben faulting that constrains the jadarite and NaBo mineralisation.

The orebody will be extracted using underground mining methods which are variants of cut and fill, and bench stoping. Mining panels were generated on regular grids within each structural zone. Internal to these panels, individual mining stopes and associated development accesses were created for interrogation and scheduling.

The underground mine will be accessed via a twin shaft system located outside the Jadar River floodplain to the southwest of the LJZ. The main production shaft will be 8.5 m diameter and equipped with two 9 t skips capable of hoisting a peak 7,200 t/day of ore and rock waste material.

Development of the flowsheet to process the jadarite mineralised material has been accompanied by extensive laboratory testwork and piloting over a period of approximately ten years. The flowsheet incorporates standard unit operations arranged in a manner to suit the unique lithium and boron mineralogy associated with the Jadar resource and consists of three main sections:
1. Comminution and beneficiation to produce a jadarite concentrate.
2. Hydrometallurgical processing of the jadarite concentrate to produce unrefined lithium carbonate, technical grade boric acid and anhydrous sodium sulfate.
3. Bi-carbonation of the unrefined lithium carbonate to produce battery grade lithium carbonate.

Comminution and beneficiation involves a relatively simple circuit, taking advantage of thehardness differential between the hard jadarite particles and the much softer host rock toproduce a 4 mm/+0.2 mm jadarite concentrate, with the -0.2 mm fraction rejected as beneficiati ........