Coke-based carbon sorbent (CBCS) was produced using special coke fines with the following characteristics: ash, 4.5%; iodine adsorption capacity, 52%; specific surface area, 600 m² g⁻¹; and total pore volume, 0.4 cm³ g⁻¹. Gold adsorption from real production cyanide solutions in batch and column laboratory experiments was studied. The optimum adsorbent/solution ratio was 0.2 g/20 cm³. Sorption equilibrium occurred after 60 min of phase-time contact. The CBCS maximum adsorption capacity for gold was found to be 1.2 mg g⁻¹. Both the Langmiur and Freundlich isotherm models confirmed that gold adsorption by CBCS proceeds favorably, but the Freundlich isotherm best describes the adsorption equilibrium. The CBCS dynamic exchange capacity (100 g t⁻¹) and full dynamic exchange capacity (4600 g t⁻¹) for gold were determined in column tests. It was revealed using SEM that adsorbate was retained in sorbent pores. The possibility of completely eluting gold from CBCS was demonstrated. A CBCS pilot test to recover gold from 200 dm³ of the cyanide solution containing (mg dm⁻³) 2.6 Au, 0.42 Ag, and 490 Cu was carried out. The total amount of noble metals (Au + Ag) adsorbed was 99.99% and gold ions was 94%. The CBCS maximum adsorption capacity for gold reached 2900 g t⁻¹.

The results of model studies on the possibility of reducing energy costs and carbon dioxide emissions during the Waelz process of oxidized zinc-containing material are presented. Herewith,...

Despite lead hydrometallurgy has been developing rapidly over the recent years, the major part of lead in the world is still being produced using various lead smelting technologies. Meanwhile, the conventional lead smelting process combining both oxidizing roasting of lead charge and reduction shaft smelting, has become inappropriate in terms of modern nature protection requirements, therefore ecologically friendly direct lead smelting processes have gradually been expelling it. In terms of the technical arrangement, all these processes can be divided into two main types, bath smelting and flash smelting namely. The 1st objective of the paper is making an analysis of the correlations between technical arrangement and technological capabilities of direct lead smelting processes with the natural patterns of lead and lead compounds behavior. The 2nd objective is determination of the role which technical arrangement of the process can play for selection of the technology for modern lead operation. The paper reviews peculiarities of the technical arrangement of the direct lead smelting operations, physical-and-chemical patterns of lead and lead compounds behavior in these processes, as well as technological capabilities of direct smelting processes with regard to the quality of lead feed. The paper makes a special reference to the peculiarities and advantages of KIVCET process, which is the oxygen-flash smelting process developed in Kazakhstan. The main conclusion made in the paper is the possibility to restrain the impact which the nature of lead and lead compounds have on technological capabilities of direct lead smelting through specific technical arrangement of the process. Taking this circumstance into account can be useful when making a choice of the technology for lead operation, considering the necessity to get it integrated with other metallurgical operations and design feed quality.