reward minerals returns high potassium

http://www.proactiveinvestors.com.au/companies/news/41780/reward-minerals-returns-high-potassium-recoveries-from-lake-disappointment-41780.html

Reward Minerals returns high potassium recoveries from Lake Disappointment
Tuesday, April 09, 2013 by Angela Kean


Reward Minerals (ASX: RWD) has received encouraging preliminary results from its pilot scale evaporation trial of brine from its Lake Disappointment Potash Resource in Western Australia.

The results show a high yield of potassium, with an overall recovery of 87.5% of the feed potassium to the bulk harvest.

Of the 87.5% recovery, 40% potassium recovery was achieved in Stage 3 Mixed Salt at a grade of 8.8%.

A further 47.5% potassium recovery was achieved in Stage 2 Mixed Salt at a grade of 3.44%.

Combining Stage 2 and Stage 3 Mixed Salts the total harvest recovery of 87.5% provides a composite grade of 4.8%.

The trial continued for 180 days and the evaporation rate averaged 7 to 8mm per day.


Higher grade potential

The 8.8% potassium grade of the stage three harvest is high and demonstrates that high grade mixed salts can be achieved from evaporation of Lake Disappointment brines.

Reward believes the Potash grade of the total harvest can be significantly improved with tight control of the timing of brine-transfer to the Potash crystalliser ponds.

A higher grade harvest should also be achievable by back mixing of high MgCl2 end brines to the lake brine feeding the evaporation ponds.

The grade versus recovery parameters are not finalised as yet but it is expected that a recovery of a 6.5% potassium harvest at 70% recovery should be achievable.

Further laboratory scale trials are in progress to establish this commercial trade-off between harvest grade and overall potash recovery for the evaporation pond system.

Reward had around A$2.9 million in cash at the end of December 2012.