Adding Value Through Optimizing Exploration TechniquesELMER BILLEDO, PhD Mines and Geosciences Bureau, DENRROGEL SANTOS, PhD MacroAsia Mining Corp. (former MGB)ANTONIO APOSTOL, Jr., MSc Mines and Geosciences Bureau, DENR

FOCUS

Analysis of future nickel potential in the Philippines

Finding the best deposits and highest grades in limonite and saprolite

Cost effective solutions for mining firms

Outline of Discussion

Nickeliferous laterites and the accreted terranes (ophiolites) in the Philippines: exploration foci

Terrain and the laterite maturity: Hole grade vs. laterite thickness Lithology and the laterite composition Density and the laterite resource Mechanized drilling vs auger vs test pits Resource estimation: geostatistics and physiographic boundaries Value-adding schemes: looking for “unconventional metals” The bedrock as carbon repository: a “bonus”

Accreted Terranes: Foci for Exploration Roughly 5% of the Philippines

landmass is composed of ophiolites where more than half of exposed lithology is the ultramafic base

Dominant ultramafic rock is harzburgite which has better Ni background

STA. CRUZ (Benguet Corp.)19.52 MMt, 1.36% Ni

ISABELA (PGMC)42.38 MMt, 1.16% Ni

NONOC141 MMt, 1.10% Ni

RIO TUBA (Coral Bay)40.45 DMt 1.30% Ni

MINDORO (Intex)87.53 MMt, 0.95% Ni

ACOJE (DMCI)30.2 MMt, 1.13% Ni

AGATA (MRL)18.1 MMt, 1.13% Ni

INFANTA (MacroAsia)92.43 MMt, 1.01% Ni

TORONTO (Citinickel)6.39 MMt, 1.80% Ni

PULOT (Citinickel)8.21 MMt, 1.71% Ni

CASIGURAN Century Peak10.79 MMt, 1.11% Ni

HINATUAN (NAC)3.0 DMt 1.50% Ni

PUJADA (Asiaticus)200 MMt 1.3% Ni

TAGANITO (NAC)75.6 Dmt 1.14% Ni

GLOBAL23 MMt, 1.75% Ni

BOTOLAN (Nihao)

MANTICAO

BUKIDNON

GUIAN

SIBUYAN

MT. KADIG

TAWI-TAWI

BERONG (TMM)140M @1.41% Ni

MANICANI (NAC)34.31 DMt, 1.11% Ni

CADGIANAO (NAC)7.37DMt 1.64% Ni

CARRASCAL 21.0 MMt 1.10% Ni

Location of known Nickel deposits

Mineral resource and Ni grades of some deposits in the Philippines as compared to other countries.(JICA, 2009)

MGB validated Ni Projects for DMPF applications from 2011-2015.

CTPNORTH DINAGAT

CARASCAL NICKEL

ZAMBALES CHROMITE

SINOSTEEL

COMET

MARCVENTURES

LIBJO

MINIMAX

WELLEX

AAM-PHIL

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 20 40 60 80 100 120

NIC

KEL

GRA

DE (%

)

TOTAL MINERAL RESOURCE (MILLION METRIC TONS)

Terrain and the Laterite Maturity

ISOPACH MAP ISOGRAD MAP There is a positive correlation between thickness of laterite and the weighted average grade

of nickel;

Gentle terrain correlates well with thickness of laterite.

Terrain and the Laterite MaturityNi% Hole Average vs. Thickness - Berong Area

-

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

0 5 10 15 20 25 30 35

Thickness (meters)

Ni%

Ave

Ni% Hole Average vs. Thickness - Ipilan Area

-

0.50

1.00

1.50

2.00

2.50

3.00

3.50

0 10 20 30 40 50 60

Thickness (meters)

Ni%

Ave

Ni% Hole Average vs. Thickness - MacroAsia Area

-

0.50

1.00

1.50

2.00

2.50

3.00

0 5 10 15 20 25 30 35 40 45

Thickness (meters)

Ni%

Ave

Central Palawan South Palawan

South PalawanNorth Bicol

Lithology and the Laterite Composition

Dunite or dunite-dominant terrane yields Fe-hydroxides and oxy-hydroxides laterite profile and may not produce distinct saprolitic zones or horizons;

Harzburgite-based laterite produces higher nickel yield due to formation or precipitation of transported nickel near saprolite-bedrock interface;

Garnierites, a complex hydrous silicates of Ni, form only if bedrock is composed of harzburgite or in a harzburgite-dominant terrane;

Lithology and the Laterite Composition

Density and the Laterite Resource In a well formed laterite stratigraphy, i.e. with distinct horizons of

limonite, earthy saprolite, and rocky saprolite, density decreases from limonite downwards to rocky saprolite;

The “reversed” trend is attributable to the mineralogical assemblage per matrix;

Density and the Laterite Resource In resource estimation density almost always receives the least

attention on quality control Geochemical analysis has check samples in form of

duplicates, internal standards, etc.; Drill hole location and topographic survey are always checked

on the references used and take on re-shots; The Philippines is not an exception. Most mines simply adopt values

from past exploration programs either by the mine itself or mines operating adjacent to it. Such became the root or irreconcilable figures between resource and reserve; reserve and shipped materials.

Sand replacement method is very effective for in-situ, bulk density determination due to non-uniformity of particle sizes in various matrices of laterite;

In-situ Density MeasurementLeveling the ground

stabilizing the base plate

Getting volume of materials for swell tests

Pouring the “standard sand”

Recovering the remaining sand

“the footprint”

Samples are weighed

Sample Collection: Mechanized Drilling, Auger, and Test Pitting Mechanized hydraulic drilling

outperforms most of the other sampling “tools”;

Grid drilling is most effective in layered deposits of limited thickness but wide lateral extent like laterites;

Dry drilling using single barrel added efficiency to lateritic drilling without jeopardizing the sample integrity

Resource Estimation: Geostatisticsand the Physiographic Terrane Dividing by physiographic terrane

enclose sampling points which bear interrelationship and genetic continuity during mineralization or ore development;

Faults, valleys, or water bodies may serve as bounding lines or perimeter for each terrane;

Ordinary kriging yields lesser bias thus very effective for the extensive lateral mineralization in laterites;

5 east

5 west

4

3

21

Value Adding: Looking for “Unconventional Metals”

• Within the laterite profile Sc has the largest concentration within the limonite;

• Sc shows linear positive correlation with Fe, Co, Mn, Al, and Cr from bedrock to earthy saproliteexpressing its susceptibility in weathering;

• Reversal in trend which marks the boundary between earthy saprolite and limonite may imply processes occurring within the limonite

02468

101214

0 20 40 60 80 100

Al2O3 vs Sc

Sc

Al2

O3

LimoniteSc: 57-65ppmY+Ln: 4-5ppm

TransitionEarthy saprolite

Sc: 33-56ppmY+Ln: 3-48ppm

Rocky SaproliteSc: 6-17ppmY+Ln: <2ppm

DH1 (22m depth)

Mn

cont

ents

(0.

8-1.

8%)

Scandium Geochemistry

Scandium ChemistrySCANDIUM AND THE REES

Scandium (Sc) forms part of the REE family to include Yttrium (Y)

The small ionic radius of Sc easily substitute for Fe+2, Mg, Zr, and Sn

As such it occurs in a diverse of resource types igneous ilmenite, hydrothermal Sn-W ores, to residual bauxite and laterite (Chackmouradian & Wall, 2012)

Sc is one of the most expensive commodity among REEs and the most abundant too

Sc, occurring as trivalent ion, has small ionic radius making it classified as HREE

The Peridotite Bedrock: As Carbon Repository –Laterite Mining “Bonus”?

Experiments for the past decade showed the high potential of harzburgite and dunite, protoliths or source rock of Ni-laterite, as carbon repository;

The high magnesium (Mg) contents of the laterite bedrock react with CO2 as gas or CO2 dissolved in water to produce magnesite (MgCO3) – a stable mineral which itself has industrial application;

With such high Mg contents and the refractory nature of the peridotite bedrock make it potentially useful for acid mine drainage mitigation and as refractory brick respectively;

Progress is technology utilizing these characteristics of the bedrock will lead to waste free or green technology mining for Ni-laterite or perhaps even in chromite mining.

The Mineral Carbonation Concept

(After Power et al., 2013)

Conclusion With 5% of the Philippine land area as accreted terranes – Ni-laterite

potential sources are still vast; Having known presence of other “unconventional metals” such as REEs

and perhaps PGEs will be an added value to a Ni-laterite property and to the future of its mining;

Having proven as carbon repository the peridotite bedrock as wastes of Ni-laterite mining may have its exclusive “green Market” in the future;

Knowing the foci for Ni-laterite exploration, the correlation of bedrock composition to its Ni contents in laterite, and the correlation of terrain-laterite thickness-Ni grade will greatly optimize the exploration program

Consideration of density having equal importance as laterite grade-geochemistry, and topographic survey will provide solution to long held problem of reconciling resource-reserve and reserve-shipped out materials in most mining operations.

THANK YOU & GOOD DAY!