Stibnite (Sb2S3) Solubility in Sodium Sulfide Solutions

Science  30 Sep 1966:
Vol. 153, Issue 3744, pp. 1673-1674
DOI: 10.1126/science.153.3744.1673


The solubility of stibnite ( Sb2S3) was measured at 25°C and 1 atmosphere in solutions ranging from 0.45 to 7.16 percent Na2S by weight. Sb2S3: Na2S mole ratios of saturated solutions range from 0.238 to 0.403. Stibnite solubility increases at an increasing rate with rising Na2S concentration. The reaction that best fits the experimental data is 2Sb2S3 + HS- + OH-= Sb4S72- + H2O, for which an equilibrium constant was estimated to be about 5.0.