Alba Min Res PLC - Amitsoq Update
Released
Released
Announcement PDF
RNS Number : 8534R
Alba Mineral Resources PLC
31 October 2019
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associated PDF document (including maps and images): http://www.rnspdf.londonstockexchange.com/rns/8534R_1-2019-10-31.pdf
Alba Mineral Resources plc
("Alba" or the "Company")
Amitsoq Processing Testwork Achieves
High-Grade, Premium-Flake Product
Alba Mineral Resources plc (AIM: ALBA), the diversified mineral exploration and
development company, is pleased to announce that it has completed a Phase 2
metallurgical testwork programme in respect of the Company's exceptionally
high-grade Amitsoq graphite project in southern Greenland. This programme
has confirmed that Amitsoq graphite is amenable to the production of a highgrade refined product and that a significant proportion of the flake graphite in
the product comprises larger-sized flake graphite which attracts premium
prices.
Highlights
·
Building on prior results, this round of testing confirms that a saleable
(97.3% TGC) product can be produced from Amitsoq graphite.
·
The Phase 2 testwork programme has been designed to maximise the
level of high-value flake graphite in the refined product.
·
Image analysis shows that 36% of the refined product consists of large,
jumbo and super jumbo flake sizes, which attract a premium price in the
graphite market.
·
This is a very positive and potentially very significant result, as it
indicates that higher-value flake graphite will be among the products
that may be produced from Amitsoq graphite, which will greatly assist in
the development of a positive technical economic model for the project.
·
Alba will now move on to the design of a further phase of refining
testwork.
George Frangeskides, Alba Executive Chairman, commented:
"This
completed Phase 2 test programme for our exceptionally high-grade graphite
project at Amitsoq confirms two very important things. Firstly, that a saleable,
97.3% product can be produced. And secondly, that in that refined product is
included a significant proportion of the higher-value flake graphite that is soughtafter for a range of industrial uses, which still underpin the majority of the demand
for natural flake graphite globally. This will be very important for the future
economics of the Amitsoq Project."
"We will build on this latest phase of work with further refining testwork, and also
to assess the amenability of Amitsoq graphite to produce a very high purity
product suitable for the battery metals sector."
"This completed work on one of our key assets provides us with great confidence as
we move into 2020."
Introduction
Alba
contracted
process
metallurgical
consultants
Southern
Cross
Mining
Limited
("SCM")
to
design
and
supervise
a
mineralogy
and
process
study on the Amitsoq and Kalaaq graphite deposits in southern Greenland and
to report on the findings. The primary objective of the study was
to
recover
a
high
purity
graphite
product
with
a
focus
on preserving graphite flake size. The testwork included the following technical
components:
1)
Microscopic analysis of resin-mounted samples and
feed, concentrate and tailings.
2) Bench-scale batch rougher and cleaner flotation tests.
3) Hydrometallurgical refining of the flotation final concentrate.
flotation
The Phase 2 programme was carried out on 25 kg of channel samples taken
from
the
Upper
Graphite
Bed
("UBA")
and
Lower
Graphite Bed ("LBA") at Amitsoq, as well as from the Lower Graphite Bed at
Kalaaq ("LBK"). See Figure 1 in the PDF version of this announcement for the
Project location.
The samples were submitted to mineralogy and petrology specialists Petrolab
(Cornwall, UK), for crushing and preparation of resin-impregnated blocks and
slides, which were then submitted for petrographic analysis to MSA Global, a
specialist South African firm.
The balance of the channel samples were submitted to Geolabs Global Limited,
a metallurgical and mineralogical laboratory in South Africa, for
beneficiation and refining.
Bench-scale flotation trials were conducted
in conjunction with stereomicroscopic analysis of flotation product streams.
The final flotation concentrate was then submitted for acid leaching as a
proof of concept for hydrometallurgical refining to reach the final Total
Graphitic Carbon ("TGC") grade.
The main objectives of this programme were to maximise the final product
grade and flake size, and to identify a possible process flowsheet for coarseflake graphite recovery. The programme was split into four phases:
petrographic analysis; flotation tests; purification of final concentrate; and
determination of flake-size distribution in final concentrate.
First Stage Testwork: Petrographic Analysis
Identification of spatial variations in graphite and gangue mineral
characteristics was achieved via petrographic analysis of resin-mounted
blocks
and
thin
sections.
Reflective
and
transmissive
light
microscopy were used to estimate grind sizes required for initial
flotation trials based on the observed graphite flake sizes and degree of
gangue mineral interlocking. A brief summary of the findings is set out in Table
1 below.
Table 1: Summary of petrographic analysis of resin-mounted blocks and thin sections
Sample Description
Max flake
length (µm)
Ave. Flake
Size (µm)
Gangue Mineral
Association
Estimate (µm)
Lower Bed, Kalaaq
820
278
Often interlocking
Upper Bed, Amitsoq
1230
440
Very minor interlocking
Lower Bed, Amitsoq
1270
472
Very minor interlocking
Lower Bed, Amitsoq
1550
513
Minor interlocking
This testwork programme was focused on the Amitsoq
Kalaaq material will be the subject of a future testwork programme.
material.
Second Stage Testwork: Flotation Tests
To
concentrate
coarse-flake
graphite,
graphite
from
both
the
upper
and
lower
beds
at
Amitsoq
was
subjected to a series of flotation sighter tests to scope potential
process flowsheets suitable for producing a final graphite product. Based on
stereoscopic observations, mass distribution and total graphitic carbon
("TGC")
assay
data,
a
combination
of
flotation,
recrushing and leaching steps were selected.
Collectively, these steps
can be summarised in a conceptual process flowsheet as set out in Figure 2 of
the PDF version of this announcement.
Rougher flotation was
used
to generate
a
crude
concentrate
with
several
subsequent
stages
of
cleaner
and
recleaner
flotation
to
selectively
recover
liberated
graphite.
Stereomicroscopy
gave
insight
into
the
degree
of
liberation, approximate mineral abundance and mineral association to
guide subsequent cleaning and size reduction steps. Final refining by leaching
was employed to meet the target TGC grade without overgrinding of coarse
graphite. The main findings of this section of the work are as follows:
(a)
Flotation parameters were selected from petrographic observations and
yielded the results in Table 2 below.
Table 2: Two-Stage Rougher Flotation Results
Location
pH
Initial Crush Size
(mm)
First Rougher
Recovery
Second Crush Size
(mm)
Total Recovery
Total Mass Rejection
(b)
Upper Bed
Amitsoq
("UBA")
9
1.7
Lower Bed
Amitsoq
("LBA")
9
1.7
Lower Bed
Kalaaq
("LBK")
9
1
85.8%
81.4%
82.8%
0.6
N/A
N/A
98.4%
27.8%
85.6%
47.1%
82.8%
40.9%
The best cleaning results were obtained by six stages of cleaning,
followed by crushing and recleaning the cleaner tailings. Results
for this method are summarised in Table 3.
Table 3: Cleaner and Recleaner Results
pH
9.5
Cleaner Feed Size (P80, mm)
0.71
Cleaner Recovery
58.6%
Re-Cleaner Feed Size (P80, mm)
0.3
Total Recovery
85.3%
Final Flotation Conc. grade
53.9%
Third Stage Testwork: Purification of Final Concentrate
Purification of the final flotation concentrate was conducted using a twostage
acid
leach
to
remove
gangue
material. The main advantage of hydrometallurgical refining is that chemical
separation of gangue does not require complete physical departure of
graphite from gangue. The final graphite grade achieved after leaching was
97.3% TGC, as listed in Table 4 below.
Table 4: Gangue Leach Results
1st Stage (HF) Mass Loss
33.2%
1st Stage (HF) TGC Grade
82.1%
2nd Stage (HF) Mass Loss
8.1%
2nd Stage (HF) TGC grade
97.3%
Fourth Stage Testwork: Determination of Flake-Size Distribution
In order to ascertain the flake-size distribution of the final concentrate,
a combination of image analysis on the coarse fraction suspended
in acetone and screening on the fine fraction was selected. The results are
set out in Table 5 below (see also Figure 3 in the PDF version of this
announcement). These results indicate that 36% of the flake size is in the
Large, Jumbo and Super-Jumbo categories, which attract premium prices in
the graphite market.
Table 5: Results of flake-size distribution analysis on final concentrate
FLAKE LENGTH IMAGE ANALYSIS
Category
Min. Size
Mass %
Cum. Mass %
Super Jumbo
500
7
7
Jumbo
300
14
21
Large
180
15
36
Medium
150
1
37
Small
75
24
61
Fine
-75
39
100
The Graphite Market: Outlook, Products and Pricing
To understand the significance of these Phase 2 test results, it is important to
put them in the context of the global graphite market and the demand for
different graphite products.
Forms of graphite
Graphite comes in different forms and specifications. The two main forms are
natural graphite, which is sourced directly from mines, and synthetic graphite,
which is made from petroleum coke. In turn, there are three main types of
natural graphite: flake (>85% carbon), amorphous (60-85% carbon) and vein
(>90% carbon).
Size is also an important factor when it comes to natural graphite. Flake size
comes in the following categories: Super Jumbo (+500 microns), Jumbo (+300
microns), Large (+180 microns), Medium (+150 microns) and Small or Fine (-150
microns). For industrial uses, Jumbo and Large flake are preferred, such as in
blast furnace steel making, castings and lubricants. In nuclear applications,
Super Jumbo flakes are used (Argus Media publication, Getting Graphite Prices
Right, 2019).
However, flake size is less relevant for high purity battery grade applications as
the graphite is micronized to less than 30 micron prior to shaping and
purification. As a result, typically only lower-cost small and medium flake sizes
or fines are used in the production of spherical graphite for battery production
(Argus Media, as above).
Production of marketable flake graphite products
Mined graphite ore is first beneficiated into graphite concentrate (typically 9497% TGC) and then sized and screened into various sizes. Flake prices are then
determined based on a range of factors such as graphite content, flake size and
impurity levels. Large, Jumbo and Super Jumbo flake with a higher purity (94%
or higher carbon content) command premium prices. Small or fine flake
graphite is reported to currently command a price of around US$400 per tonne,
Large flake US$1000 per tonne, Jumbo flake US$1400 per tonne and Super
Jumbo flake US$2000 per tonne (per www.stockhead.com.au, 16 September 2019,
quoting Roskill).
The fact that Large, Jumbo and Super Jumbo flake can attract significantly
higher prices, and that 36% of the flake within the refined product produced
from Amitsoq in the current test programme is made up of those higher-value
flake categories, is considered of potentially real significance for the future
economics of the Amitsoq project.
Production of High Purity Spherical Graphite for the battery metals sector
According to Roskill, current global graphite demand is accounted for by the
following product markets: electrodes (30%), refractories (18%), recarburising
(12%), batteries (10%), lubricants (7%), foundries (6%), other (17%). However,
Roskill have forecast that by 2029 batteries will account for 26% of the global
demand for graphite. (Roskill, "Battery and electric vehicle raw materials insights"
presentation, London, 29 October 2019).
To meet battery cell manufacturers' specifications for use as the anode in
lithium ion batteries, the natural flake graphite must be purified and shaped
into small spheres, at which point the material is referred to a High Purity
Spherical Graphite ("HPSG"). After shaping, the natural flake graphite is
purified by chemical leaching to remove impurities and raise the carbon
content to above 99.95% C. HPSG is further processed by coating a single layer
of carbon onto the spheres to produce spherical coated graphite.
(www.leadingedgematerials.com)
According to Roskill, flake graphite concentrate typically commands a price of
$650-850/t, whereas uncoated spherical graphite commands $3000-4000/t and
coated spherical commands +$7000/t. (Roskill presentation, 29 October 2019, as
above). Given the significant premium attaching to spherical graphite products,
the Company intends to include in a future work stream testwork to assess the
amenability of Amitsoq and Kalaaq graphite to produce HPSG.
Recommendations for Further Work
Recommendations for further metallurgical process work and economic studies
include the following:
(1) Tailoring of process testwork to meet the requirements of potential
concentrate offtake customers and current market demands.
(2)
Economic
cost-benefit
analysis
between
float concentrate grade and refining costs.
flake
size,
final
(3) Separate testwork stream to ascertain the amenability of Amitsoq and
Kalaaq graphite for the production of spherical graphite.
The information contained within this announcement is deemed by the
Company to constitute inside information under the Market Abuse Regulation
(EU) No. 596/2014.
Forward Looking Statements
This announcement contains forward-looking statements relating to expected
or anticipated future events and anticipated results that are forward-looking in
nature and, as a result, are subject to certain risks and uncertainties, such as
general economic, market and business conditions, competition for qualified
staff, the regulatory process and actions, technical issues, new legislation,
uncertainties resulting from potential delays or changes in plans, uncertainties
resulting from working in a new political jurisdiction, uncertainties regarding
the results of exploration, uncertainties regarding the timing and granting of
prospecting rights, uncertainties regarding the Company's or any third party's
ability to execute and implement future plans, and the occurrence of
unexpected events. Actual results achieved may vary from the information
provided herein as a result of numerous known and unknown risks and
uncertainties and other factors.
Competent Person's Declaration
Michael Nott, who has over 45 years' relevant experience in the geological,
mining, minerals, waste disposal, industrial minerals, oil, drilling, mineral
planning and quarrying industries, has approved the technical information in
this announcement.
Mr Nott holds a BSc. degree in Geology from Queen Mary, University of London,
a MSc. Degree in Mineral Production Management from the Royal School of
Mines, Imperial College, University of London, The Diploma of Imperial College
in Mineral Production Management and is a Chartered Engineer. He is a Fellow
of the Institute of Materials, Minerals and Mining, a Fellow of the Minerals
Engineering Society, a Fellow of the Institute of Quarrying and an Associate of
the Royal School of Mines Association.
Glossary
Acid leaching
Bench-scale
Beneficiation
Concentrate
Flotation
Gangue
Hydrometallurgical
refining
Sighter test
Stereomicroscopy
Metallurgical process for dissolution of metals by
means of acid solution.
Testing of materials, methods, or chemical
processes on a small scale.
Any process that improves (benefits) the economic
value of the ore by removing the gangue minerals,
which results in a higher grade product
(concentrate) and a waste stream (tailings).
Ore concentrate, dressed ore or simply
concentrate is the product generally produced by
metal ore mines. The raw ore is usually ground
finely in various comminution operations (ie the
reduction of solid materials from one average
particle size to a smaller average particle size by
crushing, grinding etc) and gangue (waste) is
removed,
thus
concentrating
the
metal
component.
Method used to separate and concentrate ores by
altering their surfaces to a hydrophobic or
hydrophilic condition - that is, the surfaces are
either repelled or attracted by water.
The commercially worthless
material
that
surrounds, or is closely mixed with, a wanted
mineral in an ore deposit
Extractive metallurgy is the practice of removing
valuable metals from an ore and refining the
extracted raw metals into a purer form.
Hydrometallurgy uses aqueous solutions to extract
metals from ores (leaching).
Sighter testwork establishes if the desired metals
can be extracted from the ore easily or not.
The stereo, stereoscopic or dissecting microscope
is an optical microscope variant designed for low
magnification observation of a sample, typically
using light reflected from the surface of an object
rather than transmitted through it.
Total Graphitic Carbon
or TGC
Carbon in rocks may be reported as total carbon
(organic carbon + carbon in carbonate minerals +
carbon as graphite) or as total graphitic carbon
(total carbon - (organic + carbonate carbon).
Therefore, when total graphitic carbon (TGC) is to
be reported, organic carbon and carbon in
carbonate minerals such as calcite should be
removed before analysing TGC.
For further information, please contact:
Alba Mineral Resources plc
George Frangeskides, Executive Chairman
+44 20 3907 4297
Cairn Financial Advisers LLP (Nomad)
James Caithie / Liam
Murray
+44 20 7213 0880
First Equity Limited (Broker)
Jason Robertson
+44 20 7374 2212
Yellow Jersey PR (Financial PR/ IR)
Sarah Hollins/Harriet Jackson/Henry Wilkinson
alba@yellowjerseypr.com
+44 20 3004 9512
Alba's Project and Investment Portfolio
Project (commodity)
Location
Ownership
Amitsoq (graphite)
Greenland
90%
Clogau (gold)
Wales
90%
Inglefield (copper, cobalt, gold)
Greenland
100%
Limerick (zinc-lead)
Ireland
100%
Melville Bay (iron ore)
Greenland
51%
TBS (ilmenite)
Greenland
100%
Brockham (oil)
England
5%
Horse Hill (oil)
England
11.765%
Mining Projects
Oil & Gas Investments
This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the
Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions
relating to the use and distribution of this information may apply. For further information, please contact
rns@lseg.com or visit www.rns.com.
END
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