Kompleksnoe Ispolzovanie Mineralnogo Syra = Complex use of mineral resources

Investigation of zinc leaching from clinker with pretreatment of raw materials by ultrahigh frequency radiation (microwave)

2025-03-07T13:08:14+00:00

The processing of zinc-containing man-made raw materials is an important task from the point of view of rational use of natural resources and reducing the environmental burden. In recent years, there has been a growing interest in efficient methods of processing such materials, since zinc is an important metal for industry. The leaching of zinc from raw materials with a solution of sulfuric acid is a key step in the hydrometallurgical production of zinc. Optimizing this process is crucial to increase the efficiency of its extraction, reduce costs, and minimize negative environmental impacts. We have investigated the process of leaching zinc from man-made raw materials with a solution of sulfuric acid, with pretreatment of raw materials with microwave radiation. Optimal leaching parameters have been determined. Clinker, a residual product of zinc ore calcination, was used as the starting material. The zinc content in clinker is 1.25%. It is shown that high zinc recovery is achieved after preliminary exposure to microwave radiation at a temperature of 600 °C. The effect of solvent concentration, the ratio of solid and liquid phases, and temperature on the degree of zinc extraction has been studied.

Physicochemical parameters of lithium sorption from hydromineral raw materials using synthesized inorganic sorbents

2025-03-27T05:26:23+00:00

This paper presents the results of a study on the physicochemical parameters of the lithium sorption process from hydromineral raw materials using synthesized sorbents. The physicochemical parameters of lithium sorption from brine, including the enthalpy change (ΔH, kJ/mol), entropy change (ΔS, kJ/mol·K), and Gibbs free energy (ΔG, kJ/mol), were investigated. The enthalpy value ΔH = -0.698 kJ/mol indicates that the process is exothermic, as it is accompanied by heat release. The positive value of entropy ΔS = 0.0122 kJ/(mol·K) indicates a low degree of order and increased randomness at the interface between the manganese dioxide-based sorbent and the brine during lithium absorption. The negative Gibbs free energy (ΔG) values, ranging from -4.401 to -4.769 kJ/mol at temperatures of 303–333 K, confirm that the lithium sorption process on the manganese oxide sorbent is spontaneous and can proceed without external influence. Additionally, the activation energy value Ea = -0.592 kJ/mol suggests a decrease in the sorption rate as the temperature increases. Using a modified Arrhenius-type equation, the adhesion probability S* was determined to be 0.188. This value indicates the predominance of the chemisorption mechanism in the lithium sorption process.