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Comparative study of an industrially used activated carbon of WSC-207C-GR brand, strongly basic anion exchanger MINIX, and weakly basic anion exchanger Purogold S992 in recovery of [Au(CN)2]– ions from cyanide aqueous solutions and slurries was carried out. It was found that the strongly basic anion exchanger MINIX has the highest adsorption rate of the cyanide complex of gold(I), whereas the activated carbon and the weakly basic ion exchanger possess a substantially higher selectivity toward the complex of gold(I). Use of each of the three sorbents makes it possible to solve the problem of the cyanide leaching of gold from ores containing natural substances that exhibit adsorbent properties with respect to the dicyanoaurate(I) ion. The influence exerted by the amount of kerosene additive and volume fraction of a sorbent on the efficiency of gold recovery by the sorbent in cyanidation of ores in the “carbon-in-pulp” and “resin-in-pulp” modes.

Possibility of using strongly basic anion exchange resin of MINIX brand and weakly basic anion exchange resin Purogold S992 brand in the high-temperature- caustic conditioning (HiTeCC) technological process for diminishing the loss of gold via adsorption on natural organic carbon-containing substances (pregrobbing phenomenon) in the course of cyanide leaching was studied. It was shown that the strongly basic anion exchanger MINIX has a higher affinity for the anion [Au(CN)2]−, compared with the microporous activated carbon WSC-207C-GR. As a result, the adsorbed dicyanoaurate(I) anion is transferred from the activated carbon to the ion-exchange resin. Reasons for binding of the dicyanoaurate(I) anion with active centers of activated carbons are considered, based on the fact that the adsorbent contains carbene-like carbon atoms. The existence of paramagnetic centers belonging to carbon atoms in the activated carbon was demonstrated by the EPR method. The suggested concept was used to diminish the loss of gold via partial oxidation of metallic gold in autoclave processing of pyrite- and arsenopyrite-containing concentrates.

Isotherms of nitrogen low-temperature adsorption on active FAS carbons and coconut-shell carbons were studied by the method of the density functional nonlocal theory. Distribution curves of micropore volumes in their width were obtained.m dodecyl sulfate in the presence of hydrogen peroxide under the action of UV light was studied.

Inorganic impurities (ash) in the composition of activated carbons of the H-type (AG-90, WSC-208C, and Norit RO 3515) and their effect on the adsorption of Na[Au(CN)2] from alkaline cyanide solutions were studied. Variants of presorption acid washing of carbons to raise their reactivity in the sorption process of Au(I) recovery from cyanide solutions and pulps and the order of technological procedures for diminishing the loss of Au(I) and adsorbent were considered. The effect of some solution components on the adsorption kinetics of the noble metal was characterized.

Criteria used to choose activated carbons suitable for sorption recovery of the [Au(CN)2]- anion from cyanide ore pulps are considered. Results obtained in the development of authors’ own tests for determining the mechanical strength and loss of carbons via their disintegration in this technological process are presented. Changes occurring on the surface of grains of activated carbon in its agitation in abrasive media and specific features of the design of sorption apparatus that can be used for rationally carrying out carbon-in-pulp and carbon-in-leaching processes are discussed.

Specific features of designing of large-volume agitators for mechanical agitation of concentrated polydisperse suspensions are considered. Mathematical models and results of model experiments are applied to obtain calculational relations that can be use to determine technical parameters of industrial agitators. The designing procedure is confirmed by the experience of industrial use of agitators with a capacity of up to 1000 m3.

Sorption of [Au(CN)2]- ions from cyanide aqueous solutions with activated carbon fiber was studied, and the effect of the gas phase composition and additives (phenol, hydroquinone, ethanol, Na2SO3, Na2S2O3) on sorption was considered. The results are compared with data on interaction of C60 with [Au(CN)2]-.

Oxidation of cyanide anions with atmospheric oxygen in aqueous solutions in the presence of Na2SO3 and NaHSO3 mixture and CuSO4 as a catalyst was studied. The reaction mechanism was proposed.