NI 43-101 Preliminary Economic Assessment - Verde Potash

Verde Potash Plc 10-3
Cerrado Verde Project
NI 43-101 Preliminary Economic Assessment
Information about internal quality control was presented as a single data batch, without
separation of the samples by grade ranges. Two evaluation methods were used, simple linear
regression and QQ (Quantile Quantile) plot.
One of the parameter used in the results analyzes was the precision. Precision is a measure of
how well the Y value represents the X value. It is most commonly used in assay quality control,
where X is the first assay value and Y is the matching repeat assay. A perfect result has a
precision of zero. Values of greater than zero represent an increasing amount of deviation; for
example a precision of 10% indicates that the difference between X and Y varies by around 10%
of X. The tests for K 2 O, P 2 O 5 , Al 2 O 3 , Fe 2 O 3 , SiO 2 , MgO and TiO 2 , had a high quality and
accuracy in the statistical analysis, with precision accuracy lower than 5%. For MnO and Na 2 O,
the tests showed a precision accuracy lower than 15%, and for CaO, the tests showed a precision
accuracy higher than 15%. The numbers of tests provided are statistically representative.
Precision of the Chemical Analysis
The sampling precision was evaluated using the method of repeated analysis for K 2 O, P 2 O 5 ,
CaO, Al 2 O 3 , Fe 2 O 3 , SiO 2 , MgO, TiO 2 , MnO, Na 2 O and LOI. In a total of 3244 samples, 108
were re-examined, representing 3.3% of the total number of tests.
Information on internal quality control was presented as a single data batch, without separation
of the samples by grade ranges. Was used two evaluation methods, simple linear regression and
QQ (Quantile Quantile) plot.
In general, the tests for K 2 O, Al 2 O 3 , Fe 2 O 3 , MgO, TiO 2 and SiO 2 , had a high quality and
accuracy in the statistical analysis, with accuracy higher than 5%. To P 2 O 5 , CaO, MnO and
Na 2 O, tests showed a precision up to 12%.
The correlation coefficient of the samples values of regular control is above 0.9, allowing it to
conclude that tests for the most important elements for the mineralization in study were
conducted with a satisfactory and acceptable accuracy.
Inaccuracy
The inaccuracy was determined as a difference in Fe 2 O 3 , SiO 2 , Al 2 O 3 , P 2 O 5 , Mn, TiO 2 , CaO,
MgO, K2O, Na2O e LOI in samples, between the values determined by SGS and those
determined by an independent laboratory ALS.
The external control was conducted for the purpose of determination of systematic inaccuracy in
the results of principal analytical laboratory. The value of the systematic inaccuracy was
estimated by the same formula as used for the internal control.
The number of repeated tests is 119, which is 3.6% from the total number of tests 3244.
In whole, the analysis of data for each laboratory demonstrates good precision of data with high
coefficient of correlation R > 0.98.
The total number of control external tests is sufficient. According to the analysis of external
control data, the accuracy of principal laboratories can be rated as satisfactory.
Standards
For quality control were used 174 standard samples, which represent 5.3% of the total number of
analyzed samples.
SRK Consulting (U.S.), Inc. September 16, 2011
Cerrado Verde_NI 43-101 PEA_343500.020_007_KG