Clay marketed by Argiletz.
© Argiletz
A better understanding of clays, natural minerals with a wide range of uses
Clays play a key role in many industrial and agricultural sectors: ceramics, cosmetics, agriculture and construction materials, as well as environmental containment and pollution management. However, adapting them to the desired uses requires a thorough understanding of their complex physico-chemical properties.
Against a backdrop of ecological transition and more stringent regulatory requirements, economic players today need to have detailed, reliable knowledge of the mineral raw materials they exploit or recycle.
It is in this context that BRGM is mobilising its scientific expertise to support industry in the advanced characterisation of clay materials.
An industrial partnership for mineral innovation
The French company Argiletz has been designing and marketing natural clay-based products since 1953. Its business is based on high standards of quality and traceability of raw materials, in a context of increasingly stringent regulatory constraints and high social expectations in terms of safety and the environment.
Argiletz called on BRGM to help it choose its clays and identify the specific properties needed to guarantee the high performance of its products, while avoiding any co-products or co-ownership that might impair the quality of the product marketed.
As we are committed to protecting life and the environment, we decided to partner with BRGM to combine scientific and product expertise.
X-ray diffraction device for determining mineral phases, at the BRGM laboratories (Orléans, 2011).
© BRGM
A BRGM solution based on recognised analytical expertise
The project carried out with Argiletz illustrates BRGM's ability to transform high-level scientific expertise into practical solutions for mineral innovation.
Behind a seemingly simple natural material lie complex issues to which BRGM has responded by mobilising its laboratories and skills in mineralogy, applied chemistry and geochemistry.
This integrated approach, based on advanced analytical methods, combines several levels of analysis:
- Characterisation of physical and surface properties: the texture and specific surface of clays are studied using techniques such as gas adsorption (BET method), to quantify the accessible reactive surfaces and assess their behaviour in interaction with their environment.
- Detailed mineralogical analyses: mineralogy is studied using X-ray diffraction, on total powder and on clay fractions, in order to precisely identify the crystalline phases at play. These analyses distinguish the different types of clay (kaolinite, illite, smectite, chlorite, etc.), assess their degree of organisation and quantify the amorphous or non-clay phases.
- Study of chemical composition and capacity: BRGM analyses the major elements, metallic trace elements and cation exchange capacity (CEC), essential parameters for understanding the chemical reactivity of clays and their ability to bind or release ions. Complementary techniques (ICP-MS, ICP-OES, gamma spectrometry) guarantee reliable, traceable results.
- Searching for organic compounds and asbestos fibres: with a view to preventing health and environmental risks, targeted analyses detect the presence of organic compounds (pesticides, dioxins, hydrocarbons, etc.) as well as regulated mineral fibres, particularly asbestos.
- Element-mobility assessment: standardised leaching tests complete the approach to assess the behaviour of clays in aqueous media and their potential for releasing elements into the environment.
The project should continue with a view to R&D to optimise the exploration process and the treatment of clays and secure the supply of mineral materials.
An operational service-offer to support transitions
Deployed at an operational level, this offer is fully in line with BRGM's missions: to support economic development while contributing to the sustainable management of ground and subsurface resources.
By combining scientific rigour, interpretation skills and an understanding of industrial issues, BRGM is positioned as a trusted partner in meeting the challenges associated with the responsible use of mineral resources with a view to sustainable development.
