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High-Temperature Enthalpies and Entropies of Chalcopyrite and Bornite.

PB196683

Publication Date	1970
Personal Author	Pankratz, L. B.; King, E. G.
Page Count	14
Abstract	Enthalpies were determined for synthetic chalcopyrite (CuFeS2) between 298 and 1,050K and for synthetic bornite (Cu5FeS4) between 298 and 1,100K by copper-block drop calorimetry. Two transitions were found for each compound. The lower transitions were both crystal transformations from tetragonal (low-temperature form) to cubic (high-temperature form). The chalcopyrite transformation occurred at 830K with a heat of transformation of 2,405 cal/mole; the bornite transformation was at 485K with a heat of 1,430 cal/mole. The other transitions were of the second order and were presumed to be magnetic in character. Enthalpy increments, entropy increments, and heat capacities are tabulated at even temperatures above 298.15K. Equations of enthalpy are also given. (Author)
Keywords	Copper ores Thermodynamic properties Chalcopyrite Iron ores Sulfide minerals Iron sulfides Enthalpy Entropy Tables(Data) Bornite Copper sulfides
Source Agency	Invalid Source Agency Code
NTIS Subject Category	99D - Basic & Synthetic Chemistry 99F - Physical & Theoretical Chemistry 48F - Geology & Geophysics
Corporate Authors	BUREAU OF Mines, Washington, D.C.
Document Type	Technical Report
Title Note	Rept. of investigations.
NTIS Issue Number	197105

High-Temperature Enthalpies and Entropies of Chalcopyrite and Bornite.

High-Temperature Enthalpies and Entropies of Chalcopyrite and Bornite.
PB196683

Publication Date	1970
Personal Author	Pankratz, L. B.; King, E. G.
Page Count	14
Abstract	Enthalpies were determined for synthetic chalcopyrite (CuFeS2) between 298 and 1,050K and for synthetic bornite (Cu5FeS4) between 298 and 1,100K by copper-block drop calorimetry. Two transitions were found for each compound. The lower transitions were both crystal transformations from tetragonal (low-temperature form) to cubic (high-temperature form). The chalcopyrite transformation occurred at 830K with a heat of transformation of 2,405 cal/mole; the bornite transformation was at 485K with a heat of 1,430 cal/mole. The other transitions were of the second order and were presumed to be magnetic in character. Enthalpy increments, entropy increments, and heat capacities are tabulated at even temperatures above 298.15K. Equations of enthalpy are also given. (Author)
Keywords	Copper ores Thermodynamic properties Chalcopyrite Iron ores Sulfide minerals Iron sulfides Enthalpy Entropy Tables(Data) Bornite Copper sulfides
Source Agency	Invalid Source Agency Code
NTIS Subject Category	99D - Basic & Synthetic Chemistry 99F - Physical & Theoretical Chemistry 48F - Geology & Geophysics
Corporate Authors	BUREAU OF Mines, Washington, D.C.
Document Type	Technical Report
Title Note	Rept. of investigations.
NTIS Issue Number	197105