Formcoke From Thailand Lignite

Formcoke was made in the laboratory from Thailand and North Dakota lignites with the objective of producing briquets of adequate compressive strength for commercial blast furnace use. Optimum conditions for laboratory scale manufacture were determined. Two lignite samples from the Li Mine, Lamphun Province, Thailand, and one from the North American Coal Company, Zap, North Dakota, were carbonized each at two different carbonization temperatures of 600°C and 900°C. Cylindrical briquets, 1 inch diameter by 2 inches high, were made from blends of the chars and asphalt or lignite tar binder. Compressive strength of formcoke was determined as a function of sample variety, carbonization temperature, char grain size, binder type, briquetting pressure, coking temperature, and heating rate during coking. Acceptable formcoke exceeding 800 psi in compressive strength was made from both Thailand and North Dakota lignite chars. The strongest formcoke briquets were produced from -35 mesh 900°C Thailand lignite char, with 15 per cent asphalt binder, briquetting pressure of 6,000 psi and heating rate of 10°C/min to a coking temperature of 900°C. The optimum conditions were 900°C char, -35 mesh particle size, 15 per cent asphalt binder, briquetting pressure of 3,000 psi, and heating rate of 10°C/min to a coking temperature of 900°C. Adequate formcoke from North Dakota lignite was produced under the same optimum conditions as above except that the 600°C char was used