Dataset for the thermodynamic simulation of the dissolution behaviour of elemental tellurium and tellurium dioxide in alkaline cyanide solutions.

It is necessary to simulate the thermodynamics of the Te/TeO2-CN-H2O systems to interpret the dissolution behaviour of elemental tellurium and tellurium dioxide in alkaline cyanide solutions. Below are the data employed to simulate the equilibrium diagrams presented in the article entitled "Dissolution behaviour of elemental tellurium and tellurium dioxide in alkaline cyanide solutions". Most of the reactions are available in the Hydra database of MEDUSA© software along with their logarithms to the base 10 of the equilibrium constants (i.e., log K). However, it was complemented with the log K of some important reactions (e.g., which describes the formation of H2TeO3). Log K values were calculated form the ΔG°f reported in the scientific literature. The databases reported can be used to compare the equilibrium constant values, replicate the diagrams presented in the cited article, and simulate other aqueous systems (e.g., those employing alternative lixiviant agents as thiosulfate, thiourea, etc.).

Acid decomposition and thiourea leaching of silver from hazardous jarosite residues: Effect of some cations on the stability of the thiourea system.

The recovery of silver from hazardous jarosite residues was studied employing thiourea as leaching agent at acid pH and 90°C. The stability of the thiourea in synthetic solutions was evaluated in the presence of some cations that can be present in this leaching system: cupric and ferric ions as oxidant species, and zinc, lead and iron as divalent ions. Two silver leaching methods were studied: the simultaneous jarosite decomposition-silver leaching, and the jarosite decomposition followed by the silver leaching. The study with synthetic solutions demonstrated that cupric and ferric ions have a negative effect on thiourea stability due to their oxidant properties. The effect of cupric ions is more significant than the effect of ferric ions; other studied cations (Fe(2+), Zn(2+), Pb(2+)) had no effect on the stability of thiourea. When the decomposition of jarosite and the silver leaching are carried out simultaneously, 70% of the silver can be recovered. When the acid decomposition was performed at pH 0.5 followed by the leaching step at pH 1, total silver recovery increased up to 90%. The zinc is completely dissolved with any of these processes while the lead is practically insoluble with these systems producing a lead-rich residue.