NI 43-101 Preliminary Economic Assessment - Verde Potash

Verde Potash Plc 11-6
Cerrado Verde Project
NI 43-101 Preliminary Economic Assessment
Table 11.1.4.6: Exchangeable Mg in the Soil After 60 Days of Incubation with Different
Sources of Potassium in a Sandy Soil
Dose K 2 O
K-Source
kg ha -1 KCl Thermo-K Verdete
Average
0 --- --- --- 0,05
200 0,05 ns b A 0,48 * a B 0,05 ns b A 0,19
400 0,05 ns b A 0,64 * a A 0,04 ns b A 0,24
Average 0,04 0,60 0,05
CV% = 12,75
DMS dose = 0,04 ; DMS source = 0,04 ; DMS Dunnet = 0,05
Averages followed by distinct letters, lowercase on the line and uppercase in the column, differ by Tukey test at 0.05 significance; ns not
significant by the Dunnett test at 0.05 significance, * significant by the Dunnett test at 0 05 significance;
This initial testwork indicates that Thermo-K provides a potentially superior source of nutrient
enrichment in soils not only for potassium but also for calcium and magnesium. In addition,
the source of potash is a non-chloride, non-sulfate source of potash and thus will not adversely
impact soil pH or salinity. In addition, Verde conducted mass balance testwork, which
demonstrated that Thermo-K is practically insoluble in water. Ergo, Thermo-K also provides a
superior source of fertilizer as it would be a slow release source of nutrients which is important
in climates with notably wet and dry seasons where traditional fertilizers have been weathered
from soils during seasonally heavy meteoric events and unavailable during the dry season
reducing the quality of agricultural soils.
11.1.5 Summary, Residual Issues and Recommendations
The testwork undertaken to date demonstrates that this unique process and product are
potentially a valuable contribution to agriculture, particularly in regions where soils have a low
natural exchangeable nutrient component. In addition although Thermo-K is relatively
expensive when compared to similar potassium concentrations from salar salts it has the distinct
advantages that:
The source of salts is a non-chloride, non-sulfate source of salt and thus will not
adversely impact soil pH or salinity components;
Additional nutrients such as calcium, magnesium and silicon are present; and
The nutrient source is slow release and as such more sustainable than traditional sources
of fertilizer and thus will have lower usage costs for farmers as less frequent applications
will be required.
However residual issues remain with the product that need to be addressed in further studies.
The rate of water solubilization of nutrients from the calcined product needs to be established
through rinse tests simulating the quench step post calcining and long term exposure to meteoric
rinsing. In addition, this testwork needs to also address potential mobilization of aluminum,
manganese and iron as well as trace metals from the Thermo-K product that would adversely
impact crop quality or yield. From preliminary studies Verde does not consider this to be a
problem but more testwork needs to be undertaken before definitive conclusions can be made.
In addition during prefeasibility assessment frequent samples to demonstrate consistency in
product production and to demonstrate lack of impurities need to be undertaken.
SRK Consulting (U.S.), Inc. September 16, 2011
Cerrado Verde_NI 43-101 PEA_343500.020_007_KG