NI 43-101 Preliminary Economic Assessment - Verde Potash

Verde Potash Plc 10-1
Cerrado Verde Project
NI 43-101 Preliminary Economic Assessment
10
Data Verification (Item 12)
10.1 Funchal Norte Target
Verde did not carry out a proper QA/QC program. The current QA/QC analysis is the internal
Bureau Veritas program.
5% of samples sent to the Bureau Veritas were then sent to SGS in Belo Horizonte to undertake
an umpire sample.
In the QA/QC program implemented by Verde in May 2010, as the analytical results are
received, they are immediately imported into the respective sampling spreadsheets, where any
undesirable analytical deviations of standards, blanks, duplicates, or inconsistency between the
sample result and its respective lithology can be easily compared. Simple inversions of sample
results and typing errors of the spreadsheets after receiving the certificates, are also common and,
therefore, all the results of all samples must be checked one by one and not only the control
samples introduced.
The accuracy, precision and contamination of the analysis should be evaluated.
All reference materials require validation, to check the level of accuracy and reliability of the
laboratories. The mistakes detected in the analytical procedures are identified and evaluated
having as reference the precision of the method.
The results for the certified reference materials (standard samples) must be between the limits of
2.SD (twice the standard deviation).
The validation method of the blank samples consists in verifying the presence of the analyte.
Therefore it is necessary to observe the detection limit of the method.
If there is any analysis deviation of the control samples or inconsistencies with the respective
lithologies, the batches should be re-examined and eventually re-sampled. Depending on the
situation, and certifying that there could not have been any mistake on sampling (which is
common), the costs of re-examination will be on the laboratory. If the blank values are very
high, the method of sample preparation should be checked. If all values for the standards are off
the defined limits, the digestion method of the samples should be checked. When the results of
standards and blanks are following a same trend, higher or lower than expected, the analysis for
all the batch of samples sent should be repeated, including the reference ones.
Besides the analysis of the results obtained, an unannounced visit to the laboratory is
programmed to check the conditions of the analysis.
Only after all results from each batch of samples are checked and validated, can information be
fed into the database.
The final validation of the results obtained is performed by an independent consultant (Qualified
Person).
Coffey Mining has reviewed the QA/QC results returned by Bureau Veritas as presented in Table
10.1.1.
SRK Consulting (U.S.), Inc. September 16, 2011
Cerrado Verde_NI 43-101 PEA_343500.020_007_KG