Exploration Drilling Guidelines for Nickel

  

GENERAL SAMPLING GUIDELINES

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EXPLORATION DRILLING

Compiled by Rod Tolentino

  

November 2007

This document is a compilation of best sampling practices as adopted by major nickel exploration and mining companies in the Philippines. The guidelines herein complies with JORCC requirements to achieve transparency and materiality in the data gathering related to the resource and reserves estimation. The preceding general protocols have three components herein, which are:

1.   Drilling

2.   Preparation

3.   Assaying

DRILLING

General

ü  Drill holes will initially be sited by local survey teams using compass and measuring tape.

ü  Drillholes test pits are preferred reference points. At regular intervals these sites will be accurately surveyed by professional surveyors.

ü  Drilling will be carried out using man-portable rigs with minimum of NQ drill rods and tungsten carbide bits.

ü  Bedrock penetration should be three (3) metres into hard rock to ensure that bottom is not on floater; discretion may be used based on the nature/size of boulder  in any Zone C of weathering.

ü  Core recovery will be checked at the drill site after each ‘run’ and recorded in the Drill Hole Log Sheet (Appendix A).   

ü  It is essential that all drilling be logged by a geologist so that he gains an intimate knowledge of all geological aspects of the deposit.

Below are guidelines in the detailed logging of cores:

Codes for Lithological Core Logging

The matrix below is the adopted standard codes for logging as a way to classify the saprolite according to grit/rock content:

LF	Red-brown limonite (overburden)
LA	Yellow limonite (without Mn staining or veins)
LB	Yellow limonite (with Mn staining or veins)
TM	Transition Material,  Limonite + Saprolite
SAP	Saprolite (gritty clay with <10% boulders of weathered bedrock)
R_SAP	Rocky saprolite (with 10 to 50% boulders of weathered bedrock)
S_ROCK	Saprolitic rock (with 50-90% bedrock)
SD	Serpentinized Dunite
SS	Serpentinite
Hz	Harzburgite

The following classification may be used for convention as an aid in the analysis of rock distribution and screening in the saprolite and limonite where boulders are not common:

Code	Description
1	<20cm (will be acceptable for shipping)
2	20—50cm (will be screened at the grizzly)
3	>50cm (will be left in the pit)

Weathering Scale

The following is the standard:

Lithology	Classification	Characteristics
Fresh Rock	0	Black/ green/ light grey, unweathered, dense & hard
Saprolite	1	Black/ brown, slightly weathered, discoloured, still hard
	2	Brown/  gray
	3	Pink/yellowish/ brown/ green
	4	Pink/yellowish/brown/ green, friable, coarse, relatively low density with some rocky remnant textures.
	5	Brown, yellow / red, pink/ green-gray, very soft, vague rocky textures and gritty texture
Limonite	5F	Yellowish brown, very soft, clayey, low density when dry, presence of black manganese oxide streaks
Laterite	5G	Reddish brown clay texture, soft, friable when dry and very sticky when wet
Ferricrete	6	Red-black, hard, includes hematites, and iron oxides with pisolittic texture

Combinations of the various weathering “stages” could be used i.e.) 2/3, 3/4,  2-5 or 0-3. The first number in double-digit references indicates the predominant weathering stage, but the numbers separated by a hyphen include all intermediate-weathering stages.

Photography

·         Color-photograph the core in boxes (1 boxes, 1 picture), using digital cameras for easier e-compilation. The picture number should have systematic correspondence with the drillhole number.

·         Core should be photographed fresh after completing each core box.

·         Each photograph should have ‘header board’ showing: a) project name b) hole number c) box numbers for the hole d) ‘from and to’ hole depth for reconciliation of core boxes.

Field Supervision

By virtue of competence, field geologist are required to:

ü  Supervise drilling activities and hole assignments

ü  Check core recovery which should be to optimum and properly recorded

ü  Supervise core handling, numbering, packing and preparation of laboratory submission sheet/s

ü  Undertake core logging

ü  Immediate transport of core samples to preparation site and laboratoty

Other Core Features for Recording

Logging may include the following characteristics:

Ø  Serpentinisation and its degree which presents silicic nature of host rocks, thus low in Ni mineralisation

Ø  Prevalence of minerals such as olivine, pyroxene, goethite, chromite, and other minerals; such will indicate the relative level in Ni mineralization

Ø  Presence of manganese streaks (black) which are indicative of the presence of cobalt oxide

Ø  Occurrence of foreign materials such as indicators of transported debris similar to agglomerates; such will signify erratic mineral values

Ø  Grain size and distribution, esp in saprolite where size distribution is important to be recorded 

Ø  Fracturing (fracture/meter or FPM)

Ø  Rock quality description (RQD)

Field Logging Sheets

The logging sheet has been designed to conform to the above criteria and to be compatible with the resource database.

Please refer to attached format.

SAMPLING

Sampling Procedure

ü  Sampling of the drill cores will be a every one (1) meter intervals down the hole, except at distinct lithological boundaries or recognizable facies/mineralogical change

ü  Samples lengths across this boundary should stay in a range of 1.0 + 0.25m to avoid excessively short or long samples

ü  Whole core sampling is essential to eliminate bias when splitting of the core, particularly in heterogenous and saprolitic sections

Sample Preparation

Sampling will be carried out on site in an appropriate sample preparation house and equipment including a mobile jaw crusher, pulverizer and drying oven. Sample preparation is normally the bottleneck between drilling and assaying of the samples. The efficiency and appropriate number of equipment should be commensurate to the turn-in of samples from the exploration and as well as shipments.

The sample preparation is as per KPT’s procedure that also use JIS.

A strict record of duplicate samples must be kept using sample submission sheet. These sheets are to be filed separately from that of the assaying laboratory.

Wet Density Determination

There are alternative methods to measure densities, ranging from laboratory tests on mini-samples to bulk samples from trenches and open excavation faces.

The following procedures may be applicable:

·         Use 10-15cm & ‘representative’ core

·         As much as possible avoid bias in saprolites, particularly when collecting hard rock portions that may be unrepresentative. Do not sample if expected deviation is significant.

·         Initially weigh in ambient air, then immerse in water for 10 minutes to allow complete water absorption.

·         SG calculation is as follows:

                          Weight in air

      SG =   _________________________

                 Weight in air – Weight in water

                   

For small pits and shafts, in-situ bulk densities will be measured using standard geotechnical procedures.

Moisture Content Determination

Moisture content

Ø  Individual samples will be weighed prior to drying, and as soon as possible after transport from drilling sites to avoid water loss due to evaporation

Ø  The sample will then be weighed after drying but before sample crushing

Ø  The formula used for calculating the moisture percentage is:

                                  Weight of wet sample – Weight of dry sample

                   MC% =   ____________________________________    X   100

                                                    Weight of wet sample

After sample preparation 150-200gm pulp samples will be sent to the  Laboratories for analysis. The freighting will be organized under strict supervision of field staff. It is recommended that batches of approximately 250-300 samples be submitted to enable consistent assessment of laboratory performance through insertion of standard samples with each batch. Security of samples in respect of consistent numbering and transport supervision is essential.

ASSAYING

Method

Each sample will be analyzed at the Laboratory for Ni, Ca, Fe, Mg, Si and Al.

The analytical method is as follows:

Ø  Ni, Ca, Fe, Mg and Al will be assayed by dissolving a 25g charge with a two acid digest (using hydrochloric and nitric acid), and reading the results by Atomic Absorption Spectroscopy (AAS)

Ø  Si analysis for the Feasibility drilling program by a gravimetric process.

Assay Data Quality Analysis

The objective of quality control & assays is to check the precision of sample preparation, consistent performance of the laboratory and accuracy of the laboratories’ analytical results.

This can be achieved as follows:

1.    Duplicate Samples

Duplicate samples will total about 5% of all samples (1 in 20) after preparation.

These samples will be selected subjectively by the Project Geologist to systematically cover the full range & lithologies. Each sample will have a unique number, which is different from the original and can be selected during the ‘pulp to storage’ stage of the sample preparation process.

For reference purposes all samples submitted for preparation should be accompanied by the sample submission sheet.

In this way a check can be made on the field homogenization process as well as a check on Laboratory A (third party).

2.    Standard Samples

A set of standard (reference) samples has been prepared by Laboratory B (third party). These control samples consist of one high-grade limonite and one low-grade limonite (blank) taken from Mine Pit. They will be prepared, homogenized and placed in approximately 250 separate sample bags (100g each).

Separate batches of the prepared samples will be sent to Laboratory C (thrird party) and Laboratory D (third party) for analysis. This will allow unbiased double checks to calculate accepted average or benchmark values for each standard. Analysis will be for all six (6) relevant elements.

The purpose of standard sampling is to monitor the accuracy of the assay process on a batch by batch basis. For example problems such as a change in instrument calibration or change in assay protocol can be detected and rectified.

3.    Check Samples

Approximately 2% of the total sample reject pulps from Lab A should be sent to at least one independent and internationally accredited laboratory. This equates to about 1 in 50 samples.

Samples should be taken across a broad spectrum of lithologies and sent at appropriate times during the program so a constant check on Lab As analyses is maintained. 

The recommended laboratory in Indonesia is SGS, Geo-Assay and ITS .

Note:

Drillhole and assays may be e-transmitted in agreed format in Excel or Access. The agreed format should allow for easy review and resource/reserves modeling. CD copy is advised for storage in 2 separate data banks.

Rod Tolentino

Nickelphil Inc

tolentinore@yahoo.com

Mob: +63 917 5251970

DRILL HOLE LOG SHEET ___ of ___
PROJECT :
Drill-hole No.     :					Date Started :
Location           :					Date Completed :
Co-ordinate  E  :					Remarks  :
Co-ordinate  N  :					Drilling Co. :
Collar Elevation :					Logged by :
Final Depth       :					Units:
Sample No.	From	To	Litho.	Colour	Wth	% Rock	R. Size	% Rec	Comments