QA/QC Procedures

Core Sampling, sample preparation, analytical methods & QAQC procedures at Barsele Au-VMS project, Sweden


This document details the assay quality assurance and quality control program developed at Barsele.
Au-VMS project since October of 2015. This document describes sample monitoring from sampling stage and custody along with sample preparation and the precision and accuracy of metal analyses.

Since 24th January 2019 (E19801), MS Analytical in Storuman is responsible for both core cutting and sample preparation. In addition, MS Analytical in Canada is used for assaying of both Au and Multi-element of AES samples.

Drilling program

The drilling program at Barsele started on 12th of October 2015 on the Central Zone. The drilling method is currently NQ-2 which has a core diameter of 50.60mm. This drilling method came into effect on March 2017 replacing WL-76 (57.6mm core diameter) size drilling. The length of the holes varies between approximately 150-1330m. Oriented core measurements are done each 3m run. Below 350m depth (downhole) 6m runs are done if rock quality is good.

Logging sampling procedure

  • At AES core logging facility in Storuman the core boxes are placed on logging tables. Starting with the first box placed in the upper left corner on the table and the second box below it.
  • If oriented marks are present on the core the core is aligned in a 4m long core tray holder so the oriented mark can be drawn (green marker color) along the core with shorter lines indicating downhole direction. It is always the down/lower side of the core that is marked.
  • Thereafter the meters are marked by the AES technician or geologist on the boxes with blue marker color. If core loss occur this is marked on the box.
  • RQD is also done on the whole drill hole. The boundaries between different rock quality sections are marked with green marker as a Z with a I on top. Rock pieces either shorter or longer than 10cm for each section are measured. The type measured is depending on which is more abundant in the section, longer than 10cm or shorter than 10cm pieces. The total lengths of the pieces are entered into Excel spreadsheet. The number of natural occurring fractures in each section are calculated and entered into same spreadsheet. If core loss occur this is also entered into the spreadsheet that automatically calculates the RQD-value for the section in question.  This is done by AES technician or geologist
  • Magnetic susceptibility and conductivity measurements are taken at every meter mark along the hole and entered into Excel spreadsheet. This is done by AES technician or geologist.
  • During the core logging the following things are recorded;
    • ✔ lithological boundaries are marked
    • ✔ grain size and texture
    • ✔ rock color
    • ✔ alteration type and strength
    • ✔ sulphides present and amount
    • ✔ structural features (e.g. foliation, shearing, brecciation, faults, lineations) and strain
    • ✔ vein type and their width and concentration
    • ✔ alpha, beta angles and gamma angles of structural features from oriented core Sulphides or eventual notes are marked with black colored marker on the box. The logging is done graphically on paper and thereafter entered into Fusion software. A logging protocol has been developed over the period October 2015- February 2019.
  • Sampling intervals and lithological contacts are marked with red colored marker on the box and on the core as a vertical red line with a red line across. In the upper right corner of each box the name of the sample is written e.g. SEEXD101 the last three digits are written between the marked sample lines e.g. 901. Most of the core at Barsele is 1m samples. Sampling is never done across a lithological boundary. That means that a sample always starts/ends at lithological boundary or potentially at other anomalous features along the core such as much stronger/weaker alteration, less/more sulphides present.
  • After the completion of marking sample intervals and assay numbers, the boxes are photographed both dry and wet and stored on the computer and on an external backup drive.
  • The geologist that has performed marking of the samples of the core and box also fills in the Agnico Eagle sample bar coded tags. From and To depth and standard-, blank names, duplicate or field duplicate is marked on the barcoded sample tag that remains with Agnico the other part of the tag is sent to the core cutting facility/laboratory with the drill core.
  • The Agnico Eagle geologist or technician e-mails the sawing list as Excel + pdf format and also prints out shipping/batch number on paper (A4 word document) that goes with the pallet to MS Analytical in Storuman.
  • If specific gravity is done then Agnico Eagle geologist or technician e-mails this “SG order table” to MS Analytical as Excel format. Every 5th samples are done specific gravity on. More SG measurements are done if a VMS or BIF zone is intersected.

Sample handling and core sawing at MS Analytical, Storuman

  • The pallet with the core boxes that is to be sawed is moved by AES personnel into the “portal room” together with a sawing list, sampling tags, batch number paper and cardboard box with standards on top.
  • MS Analytical picks up the pallet with the core from the “portal room” and takes it into their core cutting facility.
  • MS Analytical then labels sample bags with bar coded tags containing information about; client, sample type, sample number, sample x out of xxx and batch number.
  • Sawing is done with automated core diamond saw.
  • If oriented core then the core is sawed so that the oriented core remains in the box and the other half is sent to laboratory.
  • Since 13th (batch E16583) of September 2016 a field duplicate is taken every 30th sample and sent for assaying. The field duplicate is a ¼ core sample. That means that ¼ core is left as a reference sample in the core box. This field duplicate sample gets its own sample number.
  • Specific gravity is usually done on every 5th sample. A duplicate reading is taken every 20th sample.

Sample preparation at MS Analytical Storuman

  • The sawed half core samples individually placed in a metal bucket together with MS analytical barcoded label and Agnico’s own barcoded sample tag.
  • Every sample in the metal bucket is weighted individually.

Sample preparation flow chart at MS Analytical in Storuman

  • The samples are then put into the oven to dry.
  • The dried samples are thereafter individually crushed to 85% <2mm (PRP-925 CRU) material. This crushing size came into effect on the 6th of July 2018 replacing 70%<2mm (CRU-31). The change was based on the outcome of the “VG” test done during Q1-2018 (“One way to potentially upgrade the already almost perfect assay protocol could be to go from crushing 70% <2mm to crushing 85%<2mm and thereby lower the amount of +fraction material.”). SWED-Ehd6 (4-acid digestion) and SWED-Ehd7 (Aqua regia) are the given names for the lab packages being done at MS Analytical. MS Analytical performs internal QC crushing test.
  • The crushed material is riffle split into 1Kg sample (PRP-925 SPL) and approximately 2.5kg as reject.
  • The 1kg split is pulverized into 95% less than 75 microns (PRP-925 PPU). Pulverizing QC test is done after every twentieth sample.
  • A 150gr split of the pulverized material (95% less than 75 micron) is then transfer into pre-labeled brown paper bags. The bags are thereafter packed in boxes to be shipped to MS Analytical in Canada for gold and multi element analysis.
  • The remaining of the riffle split reject crushed material, approximately 2.5kg  (“REJECT SAMPLE”) and pulverized material (~850 gr, “MASTER SAMPLE”) are packed in a single pallet with AES Batch number and MS Analytical certificate number with barcoded labels.

Sample preparation and analytical methods

The following MS analytical methods are used for the Barsele project

Preparation (PRP-925 Custom made for AES)

PWE-100Log sample in tracking system, barcode and weight
QA/QCCrushing QC test
QA/QCPulverizing QC Test
PRP-925 DRIHigh temperature drying of wet samples in drying oven
PLG-100Pulp login — Rcd w/o BarCode
PRP-925 CRUFine crushing -85% <2mm
PRP-925 SPLSplit sample using riffle splitter.
PRP-925 PPUPulverizing 1kg sample to >95% passing 75µm

Assay method

FAS-121Au Fire Assay — AA on 50g ; above 3 ppm  Au Fire Assay — Gravimetric
FAS-425Au by fire assay and gravimetric finish. 50g nominal sample weight
IMS-23048 element for acid ICP-MS (four acid digestion)
ICF-6XxDefault over limit methods for ICF-6Ag, ICF-6Cu, ICF-6Pb, ICF-6Zn
FAS-418Ag by fire assay and gravimetric finish; for Ag above 1000 ppm


FAS-121Au Fire Assay — AA on 50g ; above 3 ppm  Au Fire Assay — Gravimetric
FAS-425Au by fire assay and gravimetric finish. 50g nominal sample weight
ICP-13035 element for acid ICP-ES (aqua Regia)
ICA-6XxDefault over limit methods for ICA-6Ag, ICA-6As, ICA-6Cu, ICA-6Pb, ICA-6Zn
FAS-418Ag by fire assay and gravimetric finish; for Ag above 1500 ppm
SPG-410(Specific gravity of core sample)

The two different multi-element options that can be used are IMS-230 or ICP-130 and their associated overlimit methods. IMS-230 + ICF-6Xx= SWED-Edh6 lab package and ICP-130 + ICA-6Xx = SWED-Edh7 lab package.

Reference samples numbering and proportion

QAQC reference samples are numbered with same core sample ID series (e.g. for Barsele SEEXD……). From the start of the project in October 2015 commercial standards has been used. Standard or one blank sample has been inserted every tenth sample. Since mid-December (since batch E15535) a duplicate is also inserted into the sample sequence. That means that every tenth sample is either standards, a blank sample or a duplicate which is a coarse reject duplicate from previous sample (mother sample).

Since 13th (batch E16583) of September 2016 a field duplicate is taken every 30th sample and sent for assaying. This field duplicate sample gets its own sample number and is ¼ core sample of the previous sample. That means that ¼ core is left as a reference sample in the core box instead of ½ core.

QAQC Monitoring

Control charts are created in Fusion when the geologist is importing the assay results. If any of the standards or the blank results fails (= outside +/-2STD). The geologist report this to responsible person who decides case by case if any action is to be taken e.g. re-assaying of entire batch or not. If two standards or more fails in a batch then an investigation is initiated with potential partial or entire resampling of the batch. That is if no logical explanation is found to the two outliers.

About 7-10% selected replicate samples from selected batch will be sent in on a quarterly basis to a different (secondary) laboratory. The replicate samples should represent low-, moderate- and high grade samples (0-1, 1-3 and >3g/t) and should be reported in evenly distributed during the quarter period. A QAQC report is being prepared on a quarterly basis.