The indefatigable scientists at the National University of Lesotho (NUL) have invented a remarkable product! A self-glazing ceramic cladding of its kind!
“As far as our investigations go, this is a new material,” said Mr Thabang Malataliana, an NUL Chemical Technology graduate, Quality Control Manager at Loti Brick and a Scientist who played a decisive role in the discovery of this material.
“This product is unique!” in the words of Mr Setlhare Jane, a Research Assistant in the NUL as he presented it lately at Harvest (F.M.) radio station. There are many reasons he was right. First, it is made of unrefined local clay mined from the Burgersdorp Geological Formation of the Beaufort Group.
Second, less than a quarter of it is made of refined fractions of local stone abstracted from the mighty Molteno Formation. One of the most important geological formations Lesotho has.
An interplay of these local minerals, in highly generous quantities, with carefully chosen and very small qualities of additives, under controlled temperatures and cooling rates, lead to this distinctive material.
Forming the mystique behind the ceramic is that it was discovered accidentally as the NUL brains were pursuing a different animal altogether. An artificial stone more or less like a metamorphic rock using local sandstone. Miss Boitumelo Matsoso, an NUL graduate and now a PhD student at the University of Witwatersrand (Wits University) was one of the pioneers who focused mainly on fine-tuning the stones which she did; with a patience of saints.
After months of near constant pursuit, the result was an elusive and very brittle material which showed consistent forms of glazing. As Malataliana pursued the material further, experimenting with different forms of clay, he was glad to discover a product of amazing appearance and durability! And, a new discovery was knocking at the door!
This material, the development of which was later financed by Lesotho Funeral Services (LFS) and supported technically by Loti Brick, Lesotho College of Education (LCE) and the Ministry of Mining, is awesome indeed! For instance, it shows compressive strengths that can be twice that of normal ceramic and comparatively lower moisture content and absorption properties.
Yet, of all its properties, “it is its aesthetic appearance and beauty that will make it a hit, once it hits the market shelves,” exclaimed Mr Monaheng Masheane, an NUL graduate and now a PhD student at the University of South Africa (UNISA) and Ghent University (Joint PhD) who had a hand in its development.
“Plus achieving colours in these kinds of products would need the use of expensive pigments,” added ‘Malenkoe Mohobo, a recent NUL graduate. “But in this product, we need no pigments at all as we depend on the natural pigments inherent in the clay itself. In fact, the product resists any kind of modification with alien pigments by simply deforming!”
Further on cost saving, this material makes its own glaze, literally! “While self-glazing is not a new phenomenon, making self-glazing in our way is quite unique and of low cost,” Mr Malataliana concluded.
Usually the conventional glazing method for ceramics follows two routes: first, the clay has to be grilled at high temperatures without glaze, and then finally with an expensive glazing material. However, in our case the product is grilled once and also glazes in a one-step process, thereby saving half the energy!
But, “perhaps the most fascinating part of this product is the theory behind its glazing,” said Mr Tau Ntelane, an MSc student at UNISA and NUL Chemical Technology graduate. He pursued some work just to prove the theory behind the glazing, and in the process, developed a new method in which the product can be made at large scale. “We found that due to the presence of stone fractions, the clay sort of breathes, not air, but the glass into its surface, coating itself in a brilliant process!”
The young curious minds, now going on with their different pursuits, cannot help but look back with fascination at the miracle they left behind. Maybe, just maybe, their combined efforts will not be in vain.
This blog post was originally written by NUL Research and Innovations