Measurement of iron and lead sulfide solubility below 100 °C

The solubility of iron sulfide and of lead sulfide in water was determined experimentally in the temperature range from 25 to 80 °C and at atmospheric pressure. The solubility of iron sulfide was determined by bringing precipitated iron sulfide in equilibrium with water and determining the concentration of iron ions and of total sulfur after the equilibration. The same method was used for determining the lead sulfide solubility in water. In both cases, a difference between the concentrations of metal ion and of total sulfur was observed. The concentrations were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The time required for equilibration was studied. The particle size distribution was examined to select a proper membrane for separating saturated solution from solid material.