The researchers aimed to reduce the ash content in high ash non-coking coal from Vasundhara mines in Odisha. They used physical beneficiation techniques like gravity separation and flotation to achieve this. The coal had an initial ash content of 57%, which they successfully reduced to 25% in clean coal at a yield of 40%. They also obtained an intermediate clean product with 49% ash at a yield of 12%. The final clean coal with 25% ash content was achieved through a combination of clean coal with chemical beneficiation.