Influence of various stabilizing factors on an elemental sulfur emulsion during high-temperature leaching of nickel-pyrrhotine concentrates

Abstract

It is shown that the problems of decomposition of the three phase sulfur emulsions that form dur ing hydrothermal oxidation of pyrrhotine and the choice of conditions of their stabilization represent one of the main problems of the theory and practice of the pressure oxidizing leaching (POL) of nickel-pyrrhotine concentrates (NPCs) carried out at high temperatures. The character and the degree of influence of a number of stabilizing factors (mixing intensity, consumption of commercial lignosulphonates (LSNs), amount of added gangue) on the particle size distribution of elemental sulfur during POL of NPCs, which have different contents of the main components, are studied. Mathematical statistics is used to derive regression equations and response surfaces to describe the dependence of the extraction of elemental sulfur into hard to float par ticle size classes (-10 µm, +150 µm) on the factors under study. It is found that the key factor that determines the particle size distribution of elemental sulfur is the consumption of LSN surfactants during high temper ature leaching of NPCs irrespective of the chemical-mineralogical composition. A pronounced synergetic effect of a positive influence of LSN and a rock containing addition is experimentally detected during leach ing of high sulfur NPC.

Surface Phenomena with the Participation of Sulfite Lignin under Pressure Leaching of Sulfide Materials

“…Establishing the cause of the insufficient effectiveness of LS and the development of new highly effective surfactants and formulations of multicomponent surfactant compositions are constrained by the lack of data on interfacial phenomena, namely, the processes of adsorption, wetting, and dispersion of minerals with the participation of surfactants under conditions simulating the autoclave leaching of ores. It should be emphasized that targeted studies of surface phenomena at the mineral–elemental sulfur–surfactant boundary, carried out by Naboychenko, Goryachkin, Shneyerson, Owusu, Dreisinger, and Naftal ,− have certainly significantly advanced our understanding of the mechanisms of implementation of the surface effect of surfactants. Meanwhile, a number of issues remain which require practical verification and theoretical substantiation, in particular, the effect of the ionic composition of the liquid phase on the processes of wetting and adsorption of minerals and elemental sulfur has not been studied.…”

Sodium Lignosulfonate and Sodium Dodecyl-Sulfate Mixtures Influence on Zinc Concentrate Pressure Leaching and Zinc Electro-Winning

“…In number of works [13][14][15] formation of sulfur-sulfide and sulfur phases investigation was carried out. Investigation of surfactant influence on oxidative pressure leaching of nickel-pyrrhotine concentrate [16] allowed to establish optimal lignosulfonate consumption which provides simultaneous high leaching velocity, high pyrrhotine decomposition degree (up to 96 %) and completely elimination of sulfur-sulfide phase formation.…”

Influence of Zinc Sulfide Wetting in Surfactants Presence on Leaching Parameters

“…Interactions between sodium dodecylbenzensulfonate with polymethacrylic acid can be accompanied by intermolecular aggregates formation [12], that can lead to significant surfactant properties changing. Using of combined surfactant (lignosulfonate+ watersoluble sulfonates) for pressure leaching of nickel-pyrrhotine concentrates allowed increase degree of pyrrhotine decomposition, enhance platinum group metals extraction from leaching residues [6,13]. Synergetic action of combined surfactant allows notably reduce solutions surface tension, that can be used for intensification of ore and concentrates leaching [14].…”