1. Processing technology in the Intermediate section of tungsten-molybdenum ores of the Koktenkol deposit

2. Brief profile of the deposit
The deposit has two types of ore in its composition: molybdenum and tungsten.
Molybdenum ore is well-developed in all three deposit sections (the South, the Intermediate and the North). The amount of molybdenum ore reserves is kilotons
Tungsten ore, with maximum concentration in the Intermediate section, are of independent industrial interest and considered to be the high-priority development target. The amount of tungsten ore reserves is kilotons

3. Mineral resources of the Intermediate section
Mineral resources, according to the reserves confirmed by the State Commission for Reserves (a report of ), are represented with such commercial ores as complex (Com), scheelite (Sch) and skarn-greisen (S-G) ore types, and unpayable ores of argillaceous (Ar) type. At this, the table only includes resources being in the pit envelope. The table lists C1 and C2 reserves.

4. Tungsten world reserves and mining
Tungsten world reserves equal 3.5 m tons. More than half of these reserves locate in China. China also produces more than 80% of the world tungsten.
The Intermediate section of Koktenkol deposit reserves 254 630 tons of tungsten, which makes 7.3% of world-wide tungsten reserves.
When reached maximum capacity, overall production at Dala Mining LLP will amount to 4% of world tungsten production.
Countries
Reserves, t
Mining
2014
2015
China
71 000
Vietnam
4 000
5000
Russia
2 800
2 500
Canada
2 340
1 700
Bolivia
53 000
1 250
1 200
Rwanda
n/a
1 000
Austria
10 000
870
Spain
32 000
800
730
Portugal
4 200
671
630
Great Britain
51 000 -
600
USA
Other states
2 060
2 100
Total:
86 791
87 330

5. Traditional processing schemes
Wolframite sintering with sodium and saltpeter
Open pit
Gravity
Floatation
Fluorite making
WO3
Autoclave-sodium leaching
APT
Fluorite
Scheelite concentrate
S-G
Clay, Com, Sch
Tailings
Sintering
Open pit
Gravity
Floatation
Fluorite making
WO3
Autoclave-sodium leaching
APT
Fluorite
Scheelite concentrates
Scheelite concentrate
S-G, Sch
Clay, Com
Tailings
An open-pit method requires a traditional open pit construction. Also a construction of two concentrating plants: Gravitational - for processing clay and mixed ores and Flotating for processing skarn-greisen and scheelite ores. End products after these processes would be wolframite concentrate. Construction of hydrometallurgical plant (autoclave-sodium leaching of sheelite concentrates) would provide for an APT production.

6. Tungsten minerals
Clay ores of the Koktenkol deposit, spreading over 50 meters of the weathering crust layer and primarily associate with goethite and manganite, form part of wolframites, garnets, hydromicas and smectites group, which does not allow to use traditional flotation methods for tungsten concentrate production.

7. Distribution of valued components (W, Mo, Cu) over the depth and ore types

8. In-situ recovery (ISR) Method
Leaching solution is pumped into four injection wells
Influenced by chemical reagents, the solution becomes saturated with valuable components (becomes a pregnant /productive solution) and is then recovered through an extraction well
Pregnant solution is then settled and directed into the processing module, where end- products are being produced
Mother solution returns to the head of the process. This process continues being repeated until targeted amount of the valuable components have been extracted form the block
APT

9. Advantages of in-situ recovery
In-situ recovery method in comparison to traditional mining methods is less capital-intensive and more responsive. It avoids heavy costs connected to an open-pit construction, acquisition of mining machinery and construction of flotation plants.
Requires significantly lower capital expenditures for processing clay and mixed ores, involvement of which would hardly be possible (or at very high costs) using traditional mining methods.
Absence of the disturbance to the ground surface, no stock piles of “off-balance” ores and empty ores, and also no tailings dams (in-situ recovery is one of the most eco-friendly methods of deposit development);
Efficient management of the total output units and mining staff
ISR entirely excludes any source of dust release.

10. In-situ recovery application at the Koktenkol
Favorable geological and hydrogelogical conditions
Geological
Presence of ground water
Valuable components of weathering crust easily react with chemical reactant aggregating water-soluble compounds
Hydrological
Appropriate level of well flow rate, capacity, filtration and permeability of ores.
Two-stages technological scheme has been developed
Acidification with a hydrochloric acid
Leaching with a mixture of hydrochloric and oxalic acids
Field-testing project and construction have been completed at the site
Field-testing to confirm application of the ISL at Koktekol will be completed by the end of summer 2018

11. ICR technology for tungsten-molybdenum ore
Our technology for complex processing of tungsten-molybdenum ore (mixed and clay ore types), with in-situ recovery method, is pioneering and unique throughout the world.
Application of the ISR technology will provide low production costs of valued components and be able to meet necessary quality requirements for the metallurgical extraction.
The derived productive solution may be processed with sorbate, extractive or combined method to produce ammonium polyvanadate (APT), ferrotungsten polyvanadate, and also tungsten, molybdenum and copper concentrates.
The possibility for producing of cathode copper has been established according to the following scheme: extracting – re-extracting – electro-extracting.

12. Koktenkol Development
Pilot production is planned to begin in 2020 with initial APT production at 500 tons p/a
Initial CapEx estimated at USD 20 mln, which is 3 times less than what it would be using an open pit method
Company plans to gradually increase it production capacity to 3000 tons of APT p/a
An estimated life of mine is 35 years
Company also plans to extract copper and molybdenum as side products

13. THANK YOU FOR YOUR ATTENTION