February got off to a flying start with Ian and I heading to Melbourne for the Australian X-ray Analytical Association Workshops, Conference and Exhibitions. Nathan Webster of CSIRO and his team at AXAA did a fantastic job of compiling an interesting mix of speakers covering innovations and developments in x-ray diffraction and x-ray fluorescence techniques and instrumentation.
Ian Madsen of CSIRO (ret.) and Matthew Rowles of Curtin University kicked off the XRD proceedings with workshops spanning everything from the basics of x-ray diffraction principles to advanced quantitative analysis techniques. There were also informative presentations from Mark Raven of CSIRO on the challenges of quantitative XRD analysis on clay samples as well as a few cool projects working with carbon sequestration by Jessica Hamilton of Monash University and selective gas adsorption with metal organic materials by Josie Auckett of ANSTO to name but a few.
Dr. Helen Maynard-Casely’s (of ANSTO) public lecture gave an interesting insight into how planetary scientists can recreate the high pressure conditions deep within the core of planets and Michael Varcoe-Cocks of the National Gallery of Victoria presented the very dramatic transformations that artwork can undergo when XRF techniques are used to aid in the restoration process. You can watch them both here.
We enjoyed an entertaining dinner with great food and wine where Greg Moore and Mark Raven were honoured with the Keith Norrish AXAA Award for Excellence in X-ray Fluorescence Analysis and Bob Cheary AXAA Award for Excellence in X-ray Diffraction Analysis respectively. To finish off the week we were treated to a tour of the Australian Synchrotron. The whole conference was a great experience where we were exposed to new tips, tricks and techniques for quantitative XRD analysis many of which we are looking to incorporate into the analyses we offer to further improve the quality of the results we provide. Here’s hoping we get invited back to the next AXAA conference!
Corrosivity Testing for Bulk Shipping
DIN’t you hear? Corrosivity testing for bulk shipping is having an overhaul.
As many of you are aware, shipping requirements regulations are constantly being updated to ensure maritime and dockside safety. One of the recent focal points has been the determination of Class 8 and MHB corrosivity in bulk cargoes.
Late last year AMSA released Exemption 5450 which allows certain cargoes to be tested using an alternate test method for corrosivity determination. These cargoes have been shown to be consistently problematic when it comes to the determination of the likelihood of localised corrosion.
This exemption only applies to Coal, Bauxite, Iron Ore and Iron Ore Fines. For concentrates, you’ll be looking at Exemption 5451 for now.
So what is this alternate test?
Instead of trying to experimentally simulate the environment in a ship’s hull and measuring the corrosion rate, DIN 50292-3 allows a series of chemical and physical tests of the product to be used to predict the likelihood of the product causing serious localised corrosion.
The result of this change is that producers can obtain a more consistent result with a suite of standard laboratory tests, and be confident that their product is as safe as they think!
A significant amount of research and parallel testing has been performed by Microanalysis Australia and Curtin University on behalf of a number of industry bodies to verify the efficacy and practicality of the new test.
Please note that this exemption supersedes EX5389.
Ask us about MHB and IMDG classification for your cargo!
Cargo Liquefaction
Cargo Liquefaction is a concern for shippers and mariners alike, and when managed poorly can result in tragic loss of life and massive costs. Following several incidents over the past few years, the standard test method for transportable moisture limit (TML) and the laboratories that perform the tests have come under scrutiny under a drive to ensure the safety of crew and cargoes while maintaining commercial viability.
Microanalysis Australia has been working with shipping and mining companies to determine the suitability of relevant test methods for different products, providing rapid and relevant feedback about products, results and test suitability, and offering up-to-date information and certificates. This includes involvement in the validation and implementation of the new Modified Proctor-Fagerberg TML test for Iron Ore Fines, and providing test results for a wide range of shippers around the world.
Interest has increased in the possibility of liquefaction of products that were previously considered unlikely to liquefy, including bauxite and alumina. The suitability of the available test methods for individual products with wildly varying physical and chemical properties is also acutely relevant.
TML determination is a delicate science, which results in a report without which a ship containing bulk cargo is unable to leave port. The TML value represents a ‘safe’ moisture content, below which the cargo is unlikely to undergo liquefaction and endanger the ship and crew. It is the responsibility of the shipper to provide a moisture management plan and to prove that the cargo is being shipped with a moisture content below the TML.
There are currently three techniques suggested in the International Maritime Organisation’s IMSBC code – the flow table test, using impact testing to simulate plastic flow; the Proctor-Fagerberg test, based on a standard soil compaction test to determine saturation point; and the Penetration test, using vibrational testing to simulate liquefaction conditions. Each technique is uniquely suited to certain sample types, so explicit knowledge of the sample and the test specifics are paramount to an easy journey out of the port. Not everyone needs to be an expert – just employ a laboratory that is!
Another rising concern is the effect on the environment when something does go wrong. The regulations around bulk cargo classification are getting tighter. It is important for a cleanup crew to know if a product is hazardous to a marine environment (HME) and there is increasing demand for classification testing using marine transformation dissolution testing as more products are required to comply with Marpol Annex V. Microanalysis Australia is able to perform the relevant dissolution testing for marine and freshwater environments, as well as biological toxicity studies in synthetic stomach or lung fluids.
These changes are occurring as the Australian Maritime Safety Authority (AMSA) are continually reviewing and improving the guidelines to improve the safety of crew and cargoes. It is important to keep track of major changes and make sure that shippers know ahead of time what will be required of them and that ports are aware of the changes affecting them. Microanalysis Australia has a long history of providing the latest information to shippers and ports and assisting with understanding regulations and guidelines to help shipments go out smoothly and without incident.
Concrete is the material of choice for innumerable bridges, roads, buildings and superstructures. Though it is incredibly versatile and deceivingly simple concrete is susceptible to deterioration and deformation if not designed, mixed, poured, cured, and reinforced properly. In concrete structures, both new and old, scaling, spalling, cracking, low strength, and delamination are just a few of the deterioration artefacts that give owners, project managers and contractors cause for concern.
Concrete petrography is utilized to understand what is occurring within the concrete to account for the type of deterioration observed.
What exactly can concrete petrography do? Petrographers evaluate concrete, in bulk and in thin-section, using reflected light, transmitted light and occasionally x-ray diffractometer and scanning electron microscopes to collect an incredibly large amount of data that includes the following:
classification of coarse and fine aggregate;
identification of portland cement and supplementary cementitious materials (including fly ash, slag, and silica fume);
mix design verification including estimates of the water-cement ratio;
evaluation of consolidation and mixing;
investigate for causes of low strength;
identify causes of surface scaling/spalling (including improper finishing);
determine the depth of carbonation and depth of hydrophobic materials;
classification of secondary deposits/mineralisations;
evaluate cracking and microcracking including thermal shrinkage cracking, early-age shrinkage cracking, and plastic shrinkage cracking;
evaluate concrete for thermal damage from a fire event; and
identification of durability mechanisms including alkali-silica reaction (ASR), delayed ettringite formation (DEF), chemical attack, rebar corrosion, freeze-thaw damage, and more.
Microanalysis Australia offers a range of petrographic services that can be utilized on concrete (cores or fragments) of any age and is not specific to either new or old construction. They are also available for the evaluation other building materials such as mortar/render, stucco, aggregate, flooring, and riprap.
For more information on how we can assist you with your concrete petrography please contact our Specialist Geologist/Petrographer Dan Cukierski or Rick Hughes on +61 8 9472 4880.
The Power of the GC-MS
Microanalysis has recently acquired an Agilent 7890 GC-MS (Gas Chromatogram – Mass Spectrometer) for its new premises at East Perth.
The GC-MS will expand Microanalysis Australia’s capabilities in the areas of material identification and characterisation further into the organic sphere, specifically in the areas environmental analysis, polymer characterisation geochemical and industrial chemistry analysis.
This will complement our existing strengths in the areas of mineral and inorganic identification using scanning electron microscopy, light microscopy and x-ray diffractometry.
A GC-MS is composed of three basics building blocks:
A means of introducing the sample via an injection port.
The separation of mixtures of compounds by partitioning them between a gas phase (typically helium) and an activated solid phase attached to a silica capillary column. The difference in the chemical properties between different molecules in a mixture and their relative affinity for the stationary phase of the column will promote separation of the molecules as the sample travels the length of the column. The molecules are retained by the column and then elute (come off) from the column at different times (called the retention time).
As the helium gas phase containing the molecules passes through the mass spectrometer, they are ionised into fragments and detected based on their mass charge ratio. The fragment pattern can be matched to an internal library to provide the absolute identification of a compound.
The true power of the GC-MS is when the information of the retention time and mass fragment patterns are combined to allow the identification of compounds in extremely complex samples such as crude oils, as well as enabling the detection of pesticides, PCB and PAHs down to ppb or even ppt levels.
The diagram below provides a summary of how a typical sample would be analysed on this system.
MAA is planning to develop its investigative and analytical base over the coming months to provide clients with specialised services in the areas of organic analysis.
