PRIMARY ANTIMONY MINERALS
antimony minerals can be separated into three categories -
CHEMICAL FORMULAS FOR VARIOUS METALLURGICAL PROCESSES
Liquation is the melting of stibnite into “crudum” or “needle
antimony”. It is carried out between
Sb2S3 melts at 550° C. (Pelabon); at 540° (Wagemann); at 546° (Borgstrom).
Sb2S3 volatilizes, in the absence of air, between 650° and 917° (S.A. Chakhov and I.I. Slobodskai).
VOLATITILIZTION ROASTING: Volatilization Roasting is the process of volatilizing the sulfur and forming antimony crude oxide (Sb2O3)
Sb2S3 +9O→Sb2O3+3 SO2; begins at 290°, rapid at 520° and finishes at 560° (Saito); begins at 290°, if the size of the grain is 0·1 mm. in diameter, at 343° of 0·1 to 0·2 mm., and 430° if 0·2 mm. (Friedrich); commences at 190°, proceeds energetically at 340° and terminates at 445° (S.A. Chakhov and I.I. Slobodskai).
DEAD ROASTING: This is the process of desulfurizing sulfide ore where the oxide is not volatilized but remains as the tetraoxide or pentoxide. The Sb2O4 and Sb2O5 is then reduced to metal.
Sb2O3 + Sb2O5 --> Sb2O4
ENGLISH PRECIPITATION: In this process, sulfur is removed from stibnite by using scrap iron in the fusion. This also requires soda ash to enhance slag removal
FUMING CRUDE OXIDE TO FINISHED OXIDE:
Sb2O3+O→Sb2O4 at above 445° (Chakhov and Slobodskai).
Sb2O4+O→Sb2O5; commences at 900° and finishes at 1030° (Chakhov and Slobodskai).
Sb2O5→Sb2O4+O at between 750° and 800° (A. Simon and E. Thaler).
Sb2O4→Sb2O3+O at 930° (A. Simon and E. Thaler).
REDUCTION OF CRUDE OXIDE TO METAL: This is done using carbon and soda ash.
Sb2O3+3C→Sb2+3 CO at red heat.
LEACHING AND ELECTROWINNING TO FORM ANTIMONY METAL:
+ 3 Na2S = 2 Na3SbS3 Leaching stibnite with sodium sulfide.
2 Na3SbS3 + 6NaOH = 2 Sb + 6 Na2S + 3 H20 + 3/2 02 Electrowinning
+ 3 H = Sb + 3 NaSH Electrowinning
2011 United States Antimony Corporation
Web design by
Beaver Creek Consultants