NAKHON RATCHASIMA: Suranari University of Technology (SUT) researchers say they have created ceramic gemstones made from agricultural waste and priced 6,000 times higher than the original material.
The gemstone was a result of research by senior students at the Institute of Engineering’s School of Ceramic Engineering — Parnpailin Jaichuei, Chatcha Chuma and Saowalak Boonpakdi.
Ms Saowalak said the research was inspired by Thailand’s reputation as an agricultural land, with rice and sugarcane being the main contributors.
Agricultural products produced in the country each year result in agricultural waste, such as straw, husks and bagasse, she said.
As most of them cannot be reused to their full potential, the waste ends up being ploughed up and over and turned into fertiliser. Worse, some are burnt for disposal, causing air pollution, mainly the PM2.5 fine particles that harm people and the environment.
This concern led to the team’s research on the waste’s properties, using knowledge of ceramic engineering, she said.
Initial analysis found a high level of silica in husks and other waste. Since silica is the main element of natural gemstones, the student team decided to turn straw, husks and bagasse into ceramic gemstones.
The waste underwent a calcination process at 300, 500 and 700 degrees Celsius to change it into high-quality ash.
The ash was mixed with improver substances using the ceramic engineering method and chemical formula of the natural gemstone.
The mixture was liquified at 1,300C into molten glass before it was cooled and turned into a solidified substance.
It was then reheated in a ceramic oven at 550C to provide more durability for the gemstone and left to cool slowly for more stability, she said.
Ms Saowalak said the gemstone’s colour mirrored the material it came from. It was a size similar to that of natural gemstones, making it durable and suitable for industrial use, she said.
Moreover, it helped add value to the waste, as four-baht, or one-kilogramme waste can be made into 20 gemstones that will cost 24,000 baht in total.
