XRF and TGA Commissioning outcomes at Cape Lambert Port B

R.W.Brunning, C. Andringa-Bate Rio Tinto Iron Ore

Introduction

The Cape Lambert Port B (CLB) project comprises the construction of a new Port facility adjacent to the

Cape Lambert Port A facility (CLA). This involved the construction of a new 100Mt/a train unloading

infrastructure, stockyard, ship-loading facilities (including a new ore wharf) and the construction of an

automated sampling and analysis laboratory. Figure 1 shows CLB layout with the stockpiles in the

background, followed by the rescreening plant and the pale large building in the foreground which

houses the CLB sampling facility and analytical cell.

Figure 1. The photograph shows the location of Cape Lambert Port B Laboratory in the foreground

RTIO has traditionally designed and commissioned laboratories using semi-automated sample weighing

systems, fusion machines, Thermo-Gravimetric Analysers (TGA’s) and XRF spectrometers to process the

numerous samples produced from mining, processing and ship-loading activities. At CLB the sample

station and preparation facilities are fully automated, providing crushing, dividing, drying and sieving

Laboratory

operations. Although not originally in the scope of works, automated, analytical cell facilities were

added to the project to reduce the need to transport samples around the site.

In 2012 RTIO/SKM/IMP commenced work for the design and development of the analytical facility at

Cape Lambert Port B. The analytical facility would need to have the capacity to process cargos totaling

100Mt/a at ship-loading rates of 13,440tphr. During loading, individual cargos are composited within the

sampling cell for chemical analysis. On completion of loading the cargo; composite material is crushed,

pulverized and sub-sampled before being presented for XRF and TGA analysis. The analytical cell

comprises a vial storage magazine and a HAG-HF (fusion/weigh cell) interfaced to an Axios XRF

spectrometer and automated TGA system.

Figure 2 CLB Analytical Cell Layout

The new automated analytical facilities were required to have accuracy and a precision as good or better

than current port laboratory facilities. This paper examines the results of XRF calibration and TGA

analysis commissioning between August and December 2013. Analytical results obtained from the cell

are evaluated against the iron ore international standards for chemical analysis ISO9516 (2003 - Iron

Ores - Determination of various elements by X-ray Fluorescence Spectrometry) and hygroscopic moisture

ISO2596 (2006 - Iron ores – Determination of Hygroscopic moisture in analytical samples- Gravimetric,

Karl Fischer, and mass-loss methods).

Method

Weighing and HAG-HF Fusion

The CLB HAG-HF unit comprises of a weigh cell (Figure 3), two fusion ovens (Figure 4), and a citric acid

bath, water bath and air drying to allow cleaning of crucibles and molds. Crucibles and molds are moved

between the various areas in the HAG-HF by a single pivot mounted Mitsubishi robot. The CLB HAG-HF

design enables the continuous fusion of samples introduced via the vial storage magazine as cargo

samples are presented. The vial storage magazine also enables the introduction of general QA/QC

standards and other ad-hoc samples.

Figure 3 HAG-HF weigh cell for fusion and TGA Figure 4 HAG-HF Oven layout

The HAG-HF fusion ovens were utilized for the fusion of all XRF calibration samples. However, calibration

samples were manually weighed external to the HAG-HF due to the small weights of pure oxides to be

used and the numerous binary compounds to be fused. Calibration samples were introduced into the

HAG-HF via a manual sample input. All test samples were introduced via the vial storage magazine

utilizing the HAG weigh cell, fusion and cleaning facilities in order to evaluate TGA and XRF performance.

All test standards were allowed to equilibrate to the laboratory atmosphere over a 12hr period prior to

hygroscopic moisture analysis as required by ISO2596. Performance of TGA and XRF system was based

on the using a range of RTIO standards certified using ISO accredited methods.

Automated TGA

The HAG-HF is interfaced to the automated TGA and XRF units via a series of transport conveyors. The

HAG-HF unit extracts a test sample (2g) into a small ceramic crucible for full TGA analysis. A conveyor

then transfers the test sample from the HAG-HF to the TGA. The automated TGA set-up comprises of

four TGA units in which the sample is weighed upon entry into the first TGA (hygroscopic moisture) and

weighed at the completion of 1hr. The test sample is then rotated through the three remaining TGA’s

using the ‘automated transport mechanism. The residence time at each TGA unit is approximately 1hr.

The three remaining TGA’s are individually set at 425°C, 650°C and 1000°C. Each TGA remains at its pre-

defined temperature, and crucibles containing ore samples (as well as crucible blanks) are rotated from

furnace to furnace. Blank crucibles are used to calculate furnace factors. After ignition at 1000°C, the

crucible is removed, allowed to cool prior to being air-cleaned, ready for re-use. Figure 5 shows the four

blue TGA units with the automated transport mechanism suspended above the TGA units.

Figure 5 CLB automated TGA system

Reported shipment grades are based on a calculated iron (Calc Fe %) grade on a dry basis as detailed in

Equation 1 below

Calc Fe % = (100 – oxides % at 1000C] – LOI1000C

) / 1.4297 (1)

Where 1.4297 is the factor used to convert Fe to Fe2O

3.

It is imperative that LOI and all elemental analyses for an iron ore are determined accurately and

precisely. Since these are required to be corrected to a dry weight basis, accurate hygroscopic moisture

determination is of great importance. A simple method developed with the assistance of CSIRO (Division

of Minerals) enables the testing of several ores simultaneously for hygroscopic moisture in a single cycle

of a ‘Parcher’ apparatus (Figure 6). As detailed in ISO2596, hygroscopic moisture is determined by

heating a known quantity of ore at 105°C under a stream of nitrogen for 2hrs. Copper sulphate

pentahydrate has a known loss of 28.5-29.25% when heated under these conditions and can be seen in

the third position from the left in Figure 7. The copper sulphate pentahydrate standard was periodically

analysed with standards to ensure correct operation of the Parcher apparatus.

Figure 6 Parcher apparatus Figure 7 Ore samples place into parcher (prior to heating)

The first TGA oven to which the ore sample is introduced for hygroscopic moisture determination has

been designed to simulate as closely as possible the conditions used in the Parcher apparatus. A hollow

alumina lid allows each crucible at any position to be purged with nitrogen from above (Figure 8). Given

shipping operations are continuous and the TGA system will also operate continuously, a nitrogen

generator has been installed at CLB to supply nitrogen of >99.9% purity to TGA 1. However, during the

commissioning phase industrial grade bottles nitrogen banks were used to purge TGA 1.

Figure 8 TGA 1 lid inverted showing small nitrogen inlet holes

The importance of introducing a nitrogen atmosphere into the first TGA was examined during

commissioning. A series of 12 iron ore replicates was tested with the nitrogen on and off to examine the

effects of an inert atmosphere.

The hygroscopic moisture loss through parching the materials should be equivalent to the weight loss in

TGA 1 prior to the sample proceeding to TGA 2. A series of samples with various mineralogies were

tested over a period of six weeks to examine the accuracy and precision of the TGA 1 compared to the

Parcher method. In each test the recommendations of ISO2596 were adhered to in terms of

equilibration of samples in the laboratory atmosphere prior to analysis.

Using a variety of internal standards (which have been certified using only applicable ISO methods), the

performance of the remaining TGA’s for LOI at the various intermediate and final temperatures was

evaluated.

XRF Calibration

The CLB Port analytical laboratory will be expected to analyse 100-150 samples daily when full ship-

loading rates are achieved in late 2014. The two fusion induction furnace (HAG-HF) arrangement

commercially produced by Herzog shown in Figure 9 below is capable of fusing this volume of samples

Figure 9 CLB HAG-HF Fusion Unit

The HAG-HF fuses two samples simultaneously using two induction ovens, producing 32mm glass discs.

At Cape Lambert A and all other RTIO laboratories, 40mm discs are produced. The fused beads at CLB

were produced using 0.43g of sample to 4.4g of 12-22 lithium metaborate tetraborate flux. These

sample/flux weights are within the parameters specified for the production of 32mm fused discs in

ISO9516. The furnaces inductively heat the samples through a series of mixing and homogenization

steps prior to casting into a flat mold. Increased fusion times approaching 20minutes were utilized for

the fusion of calibration discs. All calibration samples were weighed and mixed with flux manually due to

the low weights of pure chemicals used rather than using the automated dispensing facilities within the

HAG-HF. Some 120 calibration beads were produced over a period of 10 days.

RTIO has traditionally used a series of pure standards with a commercially available synthetic calibration

standard (Syncal, XRF Scientific Batch Number 070708DB) to calibrate its XRF’s. The Syncal is mixed at

various ratios with silicon dioxide (min 99.99% SiO2) or iron oxide (min 99.998% Fe2O3) to increase the

number of calibration points for various minor and trace elements. Progressing from the mid 1990’s,

RTIO has increased the number of elements analysed from 14 to 24. The latest elements to be added

routinely for analysis have been Na and Cl. XRF Scientific introduced Na and Cl into the Syncal matrix in

2008 as NaCl on request from iron ore producers. As ISO9516 requires treatment of the pure

compounds to eliminate moisture and contamination, the Syncal standard was prepared by ignition in a

muffle furnace manually at 900°C for 20mins. This treatment of the Syncal had detrimental effects for

the As, Pb, K2O and Cl calibrations as detailed in the results section.

The inductive heating of the HAG-HF combined with the transport of molds and crucibles to and from

weigh cell–fusion-cleaning cell requires the platinum-ware to be resistant to high temperature and

robot gripping forces. Crucibles were manufactured using a 95%Pt/5%Au/0.2%ZrO2 alloy whilst

95%Pt/gold were used for the molds. The Pt/Au/Zr alloy is considerably harder than the normal Pt/Au

alloy. Temperature calibration of the furnaces is configured using an optical pyrometer which monitors

the exterior wall of the crucibles as they are heated.

Results

HAG-HF Fusion

The HAG-HF fusion equipment at CLB produces 32mm glass beads with the flux and sample weights of

4.4g and 0.43g respectively (ratio of 10.2:1). The HAG-HF fusion machine is programmed to pre-weigh a

small amount of flux followed by dosing 0.43g of sample, and finally topping with flux to achieve the

ideal sample ratio prior to mixing. Table 2 shows the sample and flux weights and ratio’s achieved over a

period of a single month running 60 unknown standards provided by Geostats. As can be seen in Table

2, all samples are well within the range of the weights specified in ISO9516, and the flux to sample ratio

is extremely small in variability.

Table 1 Flux and sample masses dispensed by the HAG-HF over a period of a month

The HAG-HF produces beads through high temperature induction, whereby the temperature of the melt

is monitored by an optical pyrometer measuring the outside crucible wall temperature between the

induction coils. Initial sulphur losses as per ISO9516 (duplicate CaSO4/Fe2O3 fusions) indicated a small

0.1% difference between duplicates on S count rates. (<2% is considered acceptable). After several

weeks of operation however, sulphur content of shipment sample duplicates showed concentration

differences of 0.01% as is indicated in Table 2.

Flux / Sample masses achieved from the HAGISO9516 / g Mean Mass / g Min Mass /g Max Mass / g

Flux 4.1 - 4.61 4.2653 4.2044 4.4049

Sample 0.41 - 0.44 0.4171 0.4134 0.4308

Target Flux/Sample Ratio 10.23

Min Flux/Sample Ratio 10.16

Max Flux/Sample Ratio 10.29

Table 2 Failure of sulphur on duplicate samples at the CLB laboratory

Sample ID S / %

Average Result 0.015

A11 0.013

A12 0.017

Average Result Fail S

B11 0.016

B12 0.006

Average Result 0.016

A21 0.016

A22 0.015

Average Result Fail S

B21 0.016

B22 0.007

The large difference between duplicate analyses was traced back to the fusion process, which was

observed to be exceeding the set temperature of 1050°C both visually and experimentally (verified using

a thermocouple). While the over temperature problem was resolved by adjusting the feed to the

induction coil, introduction of new platinum-ware still causes fusion temperature to significantly

increase. Sulphur losses were evaluated by preparing duplicate 10% CaSO4 90% Fe2O3 beads using old

and new crucibles (Figure 10). Fusion of the CaSO4/Fe2O3 mixture in a new and old crucible showed a

17% difference in sulphur count rates, while less than 2% is considered acceptable according to ISO9516.

The newer crucible showed the lower sulphur count rates, indicating overheating and sulphur loss

during the fusion process. We are currently investigating whether the temperature of the melt could be

monitored rather than the temperature of the platinum crucible wall to eliminate sensitivity of the

temperature control mechanism to the platinum surface. Alternatively temperature calibrations may

need to be performed when old crucibles are replaced.

Figure 10 - Old and new crucible exterior wall

Automated TGA

The automated TGA instrumentation determines the hygroscopic moisture, intermediate LOI’s at 425°C

and 650°C and final LOI at 1000°C of iron ore samples introduced. During commissioning the hygroscopic

moisture was evaluated using the automated TGA concurrently with determinations on the Parcher

apparatus at 105°C. Copper sulphate pentahydate sample losses during the initial commissioning of the

Parcher averaged 28.6% (expected 28.5-29.25%), confirming the Parcher to be accurate in hygroscopic

moisture determination. In October 2013, TGA 1 was changed from a routine ceramic based furnace to

an alumina block furnace in which there are multiple N2 purging points compared to 2 points in the

ceramic based TGA. The temperature we tested and adopted for hygroscopic moisture is 140°C. There

are 47 bench-top TGA’s in our Pilbara operations and previous test-work has indicated that most TGA’s

need to operate at a temperature of 140°C for the hygroscopic moisture step. Figure 11 shows the

comparative results for TGA 1 hygroscopic moisture determination (140°C alumina block oven, nitrogen

flow 6 litres per minute) versus Parcher hygroscopic moisture determination for a series of standards. As

Figure 11 shows, the data shows only periodic agreement between the two determinations during the

test period

Figure 11 Difference between TGA1 and Parcher (ISO2596) on a series of standards and samples at 140°C between Nov 2013

and Jan 2014

The agreement between Parcher and TGA hygroscopic moisture determinations appears to improve

when the difference between the TGA1 and HAG approaches 0.000g. A slightly positive difference

between the two weigh cells causes the TGA moisture to be below the Parcher moisture as seen in

Figure 11, in mid-January. The TGA1 hygroscopic moisture is calculated according to Equation 2

Hygroscopic Moisture % = –

(2)

All three parameters in the equation are to be investigated to ensure agreement between Parcher

moisture and TGA1 moisture can be maintained. The alignment between the HAG and TGA 1 weigh cells

needs to be carefully monitored and maintained to ensure good correlation between the automated

TGA and the ISO accredited Parcher method.

Previous test work has also indicated that nitrogen flow is required to ensure a uniform temperature

profile across the furnace as well as ensure rapid drying of the samples within the furnace. Introduction

of a dry, inert gas such as nitrogen theoretically decreases the vapor pressure above the samples,

allowing hygroscopic moisture to be more rapidly evolved. A test in which 12 repeat Robe Valley Pisolite

(RVP) standard samples were run in two separate trials with the nitrogen on and off were examined. The

results of the trial are shown in Table 4. The introduction of nitrogen is necessary to achieve the correct

hygroscopic moisture and subsequent LOI values. Without the nitrogen flow, the hygroscopic moisture

differed from the Parcher determined values by an unacceptable 0.60%, while introducing nitrogen flow

produced values in agreement within 0.15%. Arguably the residence time of samples could be increased

in TGA 1 with no nitrogen flow, but similar increased residence time would be required for TGA 2, 3 and

4 due to the TGA control process. This time becomes impractical in terms of throughput as the total

analysis time will be in excess of 4hours. Additionally temperature of TGA1 furnace shouldn’t be

increased above 140°C so as to avoid introduction of a positive bias between the TGA1 moisture step

and Parcher (as can be seen in some periods of Figure 11). Table 3 clearly demonstrates the need for

nitrogen purge within TGA1 to obtain correct hygroscopic moisture values aligned with the Parcher

method.

Table 3 Hygroscopic Moisture, intermediate LOIs’ and final LOI values for a series of RVP samples with

and without a nitrogen purging step for TGA1

The intermediate and final LOI values produced using the automated TGA system were assessed against

a series of internal RTIO standards and external standards provided by Geostats Pty Ltd. The latter were

submitted blindly to the CLB laboratory. Typical LOI values of the standards submitted varied from 5-

11%, which is within the range of expected products to be shipped. The differences between automated

TGA LOI results and certificate values at the various temperatures are shown in Figures 12 to 14 below.

The intermediate and final LOI values obtained using the automated TGA for the various tested samples

agree within ±0.2% of the certified values. RTIO are targeting ±0.15% or better. Towards the end of the

testing period (5th January onwards) a change has occurred in which all LOI’s are reporting higher. This

followed the shutdown of the TGA system for several days due to site experiencing cyclonic weather.

The vendor is currently assessing the reason for this deviation from target as well as the higher

variability in results observed since the shutdown.

Figure 12. LOI differences between TGA2 (425C) and certified values for standards processed between Nov 2013 and Jan 2014

Figure 13. LOI differences between TGA3 (650C) and certified values for standards processed between Nov 2013 and Jan 2014

Figure 14. LOI differences between TGA4 (1000C) and certified values for standards processed between Nov 2013 and Jan 2014

XRF Calibration

Calibration of the Axios XRF was undertaken as required by ISO9516, making a series of

standards produced using pure reagents, and also using XRF Scientific Syncal standard. The calibration

points of the Syncal standards showed significant variation from the line of best fit for the elements

PbO, As2O3, K2O and Cl in this calibration. Figure 15 below shows the PbO calibration line. The Syncal

standards at the low concentration range (0.2%) of the graph are well under the line of best fit (circled

area) when the pure PbO standards (3%) are included in the calibration. Given similar issues with other

elements (Cl, As2O3) reporting low for these Syncal standards, it was decided to remove the Syncal

standards from the calibration and use the pure compound zero points and 3% PbO standards only for

calibration.

Figure 15 – PbO calibration plot

The K2O calibration however (Figure 16), is dependent only on the results of the Syncal standard, which

appeared to be extremely linear and within specification. Independent standards fused as part of

verifying the calibration showed a maximum of 0.003% higher K2O content then expected using a variety

of standards at approximately 0.010% (approximate shipping grade concentration). However, when

analysis of CRMs containing 2% K2O was performed as part of internal QA QC programs, the calibration

produced values significantly higher than certified target grades by 0.4%. It appears that some losses for

K2O and the elements mentioned above has occurred during preparation of the Syncal standards. The

treatment of the Syncal by ignition at 900°C prior to use was investigated to determine if losses were

occurring at this stage.

Figure 16 – K2O calibration plot

0.2% PbO (Syncal after igniting)

Examination of the Syncal post-ignition treatment showed that the material had changed color

significantly and was more granulated compared with similar treatments previously completed, despite

the same batch of material being treated. At the time of preparing the standard, two separate samples

were ignited in independent furnaces in the event the first sample had been over-heated. Analysis of the

ignited material indicated losses of approximately 9, 14, 40 and 87% for As2O3, K2O, Cl and PbO

respectively. SnO2 losses were also substantial. Loss on ignition tests indicated the substantial mass

losses of 0.7% to 3% (Table 5) when a fresh sample of Syncal was treated at the temperatures of 425°C,

650°C and 1000°C. The TGA curve (Figure 17) shows the losses from the Syncal appear to increase with

temperature and not plateau even at hold times of 50minutes at 1000°C.

Table 5 LOI at various temperatures for Syncal with a hold time of 50mins at 1000°C

Figure 17 XRF Synthetic calibration (070708DB) standard mass loss (green line) with temperature (red line)

Following these findings, internal procedures for preparing the Syncal standard have been modified to

include oven drying the standard at 105°C only for 2hrs. Alternatively the Syncal could be left to

equilibrate and hygroscopic moisture determined to correct to a dry weight basis. XRF calibrations

following the new procedure for drying Syncal have shown improvements in the Syncal results for PbO.

Recent calibration plots for Tom Price are shown in Figure 18 below.

Name Initial Mass / g Moisture / % LOI 425°C / % LOI 650°C / % LOI 1000°C / %

SYNCAL 1.6746 0.32 0.74 1.14 3.44

Figure 18 PbO calibration plot showing improvement in PbO calibration for Syncal at Tom Price

The red circle in Figure 18 shows the lower concentration levels of PbO achieved when the Syncal has

been ignited. The new preparation of Syncal standards shows a PbO concentration that is in agreement

with certified values, and hence falls close to the calibration line when the 3% PbO beads are also

included in the calibration.

At full ship-loading rates, approximately 100-150 samples per day will need to be processed through the

analytical facility. However, during the commissioning phase there were many periods where the HAG-

HF was available but not required. It was found that following idle periods, when a series of the same

CRM standard was weighed through the same flux dispenser, there was a decreasing trend in the

concentration of SiO2 determined. Figure 19 shows the silica concentration for repeat standard samples

slowly decreased to a consistent concentration from the first disc measured to the last for the original

flux dispenser. The initial two HIY silica concentrations are outside 95% control limits for this CRM. A

replacement dispenser was quickly installed to re-examine this issue. The new flux dispenser shows no

decrease in silica concentration despite the flux residing in the storage container for approximately

12hrs when a similar test is performed (Figure 19). This elevated silica contamination had been

previously detected by another laboratory and was found to be due to the flux residing in the dispenser

for a period of time and silicon from an internal component leaching into the flux. Further testing has

shown normal silica and other element concentration stability when using the new dispenser.

Syncal with ignition

Figure 19 RTIO HIY CRM silica concentrations with old and new fusion standards

RTIO has various fusion instruments across its 12 laboratories in the Pilbara. These include Modutemp

TempTron, Initiative Scientific FM-4, Claisse The Ox and now the HAG-HF. Several instruments have

been found to cause Cr and Ni contamination due to the use of these metals in mold and crucible

holders and close proximity to the fusion melt. To confirm there was no cross contamination occurring

in the HAG-HF fusion, a series of high grade and low grade standards were processed through a single

oven unit. Table 6 shows that the Robe Valley standard did not deviate from the expected control limits

despite alternating fusion of the low grade European standard ECRM612-1 (higher in concentration of

trace elements and lower in iron content). These results confirm that there is little to no sample cross

contamination occurring throughout the weighing and fusion process in the HAG-HF. Specifically no

contamination was observed here for Ni and Cr or throughout the evaluation of shift QA/QC samples

during commissioning.

Table 6 Repeatability of high and low grade standards using HAG-HF fusion process

*CSIRO Division of Minerals achieved 16.63% for this standard during re-certification (Report N1281)

4.10

4.20

4.30

4.40

4.50

4.60

HIY1 HIY2 HIY3 HIY4 HIY5

SiO

2 /

%s

Sample Sequence

Silica concentration for Yandi standard produced using old and new dispenser

Silica OldDisp

Silica newDisp

Sample Fe Calc SiO2 Al2O3 P S CaO Cr Ni

RVPA/X 55.87 6.74 2.95 0.037 0.015 0.221 0.004 0.000

ECRM612-1A/X 42.41 12.68 5.63 0.872 0.052 16.648 0.021 0.012

RVPB/X 55.82 6.76 2.98 0.037 0.015 0.229 0.004 0.000

ECRM612-1B/X 42.30 12.74 5.62 0.872 0.053 16.724 0.021 0.013

RVPC/X 55.86 6.73 2.95 0.037 0.014 0.226 0.003 -0.001

ECRM612-1C/X 42.29 12.74 5.65 0.876 0.051 16.723 0.021 0.012

RVPD/X 55.85 6.71 2.96 0.039 0.014 0.240 0.003 -0.002

ECRM612-1D/X 42.40 12.68 5.61 0.874 0.052 16.674 0.022 0.013

RVPE/X 55.85 6.73 2.97 0.037 0.014 0.225 0.003 -0.001

ECRM612-1E/X 42.65 12.58 5.58 0.864 0.052 16.511 0.022 0.011

RVP Actual 55.85 6.73 2.96 0.037 0.014 0.228 0.003 0.000

RVP Cert 55.89 6.69 2.93 0.040 0.015 0.227 0.002 0.002

ECRM 612-1 Actual 42.41 12.68 5.62 0.872 0.052 16.656 0.021 0.012

ECRM612-1 Cert 42.43 12.71 5.67 0.885 0.053 16.874* 0.022 0.014

Conclusion and Further Work

As commissioning of the CLB analytical cell continues, upgrade of the control software within the

analytical system is expected to give higher reliability and improved diagnostics of the various

instruments.

The HAG-HF fusion application selected for RTIO was provided by IMP based on the use of the

application from other sites. Given the extreme narrow range of materials to be presented to the HAG-

HF from the ship-loading system, work will be undertaken to streamline and decrease fusion times. The

HAG-HF has the ability to store numerous fusion programs, hence one-off special samples introduced

(CSIRO SG9 samples) that are found difficult to fuse could be run on longer homogenizing applications

and introduced manually if they are difficult to weigh. The current focus is on maintaining the correct

temperature when new platinum ware is introduced. This is critical given the volatility of some minor

elements.

The automated TGA system installed is a first for RTIO. The system has been shown to be accurate and

reproducible during numerous periods. The introduction of the new alumina oven for moisture analysis

is an improvement which gives very good comparable results to the Parcher method used at RTIO for

the past 10-15 years. Further testwork is required to ensure that the automated TGA can continue to

give accurate and reproducible data for longer periods.

The discovery of losses caused by pre-ignition of the synthetic calibration standard has enabled

improved calibrations for several trace elements such as As2O3, Cl, K2O and PbO. Our internal procedures

have resulted in changes to the preparation of Syncal and a review of the validation standards used to

verify calibrations. The Axios Max at CLB will be extended to provide a calibration for 40mm samples to

enable fused samples from CLA laboratory to be analyzed directly on the CLB XRF in the event of a

breakdown. The CLB XRF has sufficient available capacity to run fused discs delivered from CLA. Both

CLA and CLB share the same LIMS server enabling both laboratories to generate data for samples

produced at either site.

Commissioning of the fully automated analytical facility has been a considerable challenge. Introduction

to Prepmaster software, robot logic and the pressure to achieve early success has been demanding.

Scheduled, organized training and instrument reliability remain the main focus areas to ensure that the

analytical cell continues to deliver reliable and accurate analyses. The input from many professionals at

RTIO/IMP/SKM has been appreciated given the complexity of our analytical requirements and the

flexibility that we demanded from the new instrumentation.