Abstract:
This research is aimed at a complex solution of two problems — increasing the efficiency of processing of
oxidized copper ores and utilization of sulfur-containing waste from oil and gas processing. By the methods
of chemical, mineralogical and granulometric analyzes the composition of the Sayak ore and waste sulfur was
examined. It was found that the total copper content in the ore made 2.7 %, 1.8 % of which is represented by
oxidized minerals. The main ore minerals are malachite, azurite, brochantite and chrysocolla. A thermodynamic
analysis of the interaction of oxidized copper minerals with dissolved elemental sulfur possessing the
properties of nanoparticles was carried out. The possibility in principle of copper sulfidization was established.
Based on the obtained data on the thermodynamic properties of polysulfide systems, Δf H0
298.15,
S0
298.15, Δf G0
298.15, Ср
0
298.15 of eight polysulfides — CaS2, CaS3, CaS4, CaS5, CaS6, CaS7, CaS8 и CaS9 were
defined. The temperature dependences of the standard Gibbs energy of the reaction of dissolved sulfur with
oxidized copper minerals — malachite, azurite, brochantite and chrysocolla — were defined. The possibility
in principle of sulfidization of oxidized copper minerals with dissolved elemental sulfur possessing the properties
of nanoparticles was established. It is shown that in the temperature range 298.15–500 K the formation
of copper (II) sulfide and sulfur (IV) oxide in the interaction of oxidized copper minerals with elemental
nano-sized sulfur is most likely. As the standard Gibbs energy of the sulfidation reaction increases, the minerals
can be arranged in a row up to 400 K: azurite; malachite; brochantite; chrysocolla, after 400 K: azurite;
brochantite; malachite; chrysocolla. In these rows, the probability of interaction with sulfur decreases.
