NI 43-101 Preliminary Economic Assessment - Verde Potash

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Verde Potash Plc 12-13 Cerrado Verde Project NI 43-101 Preliminary Economic Assessment For the mineralization in question the IDW method was used with the search ellipse defined by the axis of the geostatistical analysis. Was used the ellipse divided into four sectors. The search radius were determined by semi variogram models. The parameters of the search ellipse radius are presented in Table 12.2.7.1. Table 12.2.7.1: Search Ellipse Parameters to Interpolate the Grades by the IDW And Kriging Methods of Target 6 Radius Azimuth Factor Dip Factor Thickness Factor Min. Points by Sector Min. Count Fields 0.6667 324 222 30 3 2 1 324 222 30 2 2 2 324 222 30 2 1 3 324 222 30 1 1 4 324 222 30 1 1 100 324 222 30 1 1 After comparing the results of Kriging interpolation and IDW2 methods for target Target 6 (Table 12.2.9.1), it was decided to use IDW2 as the main interpolation method for the other bodies. Search ellipse parameters used to interpolate the grades for the other targets are shown in Table 12.2.7.2. Table 12.2.7.2: Ellipse Search Parameters Used to Interpolate the Grades by the IDW Method for Target 4, 7, 10 and 11 Radius Azimuth Factor Dip Factor Thickness Factor Min. Points by Sector Min. Count Fields 0.6667 150 100 15 3 2 1 150 100 15 2 2 2 150 100 15 2 2 3 150 100 15 1 1 4 150 100 15 1 1 100 150 100 15 1 1 The blocks for each zone of the mineralization were interpolated using only composite samples belonging to the corresponding part of the body. During the interpolation process was used the discretization process for each block, using a factor 4 for the X and Y axis, and a factor 2 for Z axis. This makes it possible to evaluate each block in four positions and assign to the center of the block the average of these values. This increases the accuracy of estimating the grade of each block. The constraints presented by each ellipse search sector were: the maximum number of points in the sector - 5 and the minimum point total for the interpolation, which varied depending on the size of the ellipse (from 3 to 1). Thus, the maximum total number of samples involved in the interpolation was 20. In the resources classification was used some parameters, as: the ellipse search radius (based on geostatistical studies), the kriging variance and the minimum drillhole number used in the block interpolation. In the resources classification of Target 6, inferred and indicated resources have been allocated. For the indicated resource was allocated blocks interpolated by the first and second search ellipses, with kriging variance less than 2, drillhole grid in the area about 200 by 200 m, and used in the samples interpolation at least two different drillholes. SRK Consulting (U.S.), Inc. September 16, 2011 Cerrado Verde_NI 43-101 PEA_343500.020_007_KG
Verde Potash Plc 12-14 Cerrado Verde Project NI 43-101 Preliminary Economic Assessment For indicated resource in Target 7 was allocated blocks interpolated by the first three search ellipses, with a drillhole grid about 300 by 300 m and with outcrops sampling approximately 100 by 100 m. 12.2.8 Assignment of Density Values to the Block Model The density value was allocated directly for each block of the block model. The value of 1.49t/m 3 was allocated to the oxidized Verdete blocks, and the value of 2.11t/m 3 was allocated to the fresh Verdete blocks. 12.2.9 Block Model Validation The block model with grades interpolated was submitted to a visual and statistics check. Histograms and probability plots were constructed to the interpolated grades. Then, the interpolated grades were compared with the same histograms and probability plots of the composite samples. Histograms and graphics of the interpolated grades and composite samples were similar, which confirmed the validity and consistency of the block model built. In addition, the grades interpolated were displayed and compared with the grades of the drillhole samples. This comparison show an approximate relation, indicating the accuracy of the block model built. Thus, several sections were built showing the grades of the block model and drillholes of Target 6. The average grade of the model was compared with the average grade of the drillhole samples. Comparing the IDW with power 2 and the kriging methods to the Target 6, was verified a relative difference of 1.09% between them, as shown in Table 12.2.9.1. A data comparison was made between a polygonal provisional estimate by the weighting "intervals" method and the data obtained by the Kriging and IPD2 interpolation method. These comparisons are presented in Table 12.2.9.2. The difference between the average K 2 O grades and of metal tones in relative percentage is approximately 1.26%, which also confirms the good convergence and high reliability of the block model data. The 0.03% difference between the volumes of solids and the block model are due to the use of different methods of limitations, since the block model was constrained by the method of contour. Table 12.2.9.1: Comparison of metal tones and average K2O grade of the model, obtained by kriging and IDW2 methods to Target 6 Relative difference Relative difference Tonnes KRIG Tonnes IDW2 KRIG IDW2 KRIG – IDW2 KRIG – IDW2 Cut Off Mt Mt K 2 O K 2 O K % % 2 O Tonnes Relative % Relative % 6 95.9 94.87 8.2796 8.3695 1.09 1.07 SRK Consulting (U.S.), Inc. September 16, 2011 Cerrado Verde_NI 43-101 PEA_343500.020_007_KG
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