# Study of Oxidative-Reductive Potential Changes in the Enrichment of Oxidized Polymetallic Ores
###### Abstract  
This paper presents an analysis of the current state of processing lead-zinc ores from the Koskudyk deposit (Kazakhstan). At present, polymetallic ores are being extracted from the Ridder-Sokolnoye, Zyryanovskoye, Maleevskoye, and Achisai deposits. However, the reserves of rich and easily beneficiable ores are being depleted, and the supply of raw materials from the developed deposits does not exceed 25 years. As a result, more complex and difficult-to-enrich oxidized and mixed ores are being involved in production, and the extraction of non-ferrous metals from these ores presents a significant technological challenge. The most effective method for enriching oxidized polymetallic ores is flotation with preliminary sulfidization. Laboratory studies were conducted on a sample of oxidized lead-zinc ore from the Koskudyk deposit, which contains 79.69% oxidized lead compounds and 84.72% oxidized zinc compounds. This study examines the effect of sulfidization using sodium sulfide and determines the oxidative-reductive potential (ORP) levels for various reagent dosages. The experiments demonstrated that a sodium sulfide dosage of 700 g/t at an ORP of \(-\)200 mV yields the most effective lead flotation, resulting in a lead recovery of 50.07%. Zinc recovery remained relatively unchanged across all tests, confirming the limited response of oxidized zinc minerals under the applied sulfidization conditions. The highest beneficiation efficiency was achieved within the ORP range of \(-\)160 to \(-\)200 mV, beyond which lead recovery began to decline. The findings underscore the importance of optimizing ORP to ensure the formation of a stable sulfide film on mineral surfaces and efficient collector attachment. These results provide practical guidance for improving flotation performance of oxidized ores and demonstrate the need for additional activation strategies in zinc recovery. f +
Footnote †: journal: Applied sciences  
0000-0001-6001-6001-6001-6001-6001-6001-6001-6001-6001-6001-6001-601-60 The major polymetallic ore deposits, such as Ridder-Sokolnoye, Zyryanovskoye, Maleevskoye, and Achisai, contain rich ores that are actively developed and processed. However, the reserves of rich and easily beneficiable ores are being depleted, and the supply of reserves from the developed deposits does not exceed 25 years. The prospects for the discovery of new lead and zinc deposits with high concentrations of valuable components remain relevant for nearly all regions of the republic. In recent years, the Shymerden deposit in Northern Kazakhstan, which is characterized by exceptionally high zinc content, has been involved in development. According to literature sources, 41% of lead-zinc deposits in Kazakhstan are concentrated in the Central region, 33% in the Eastern region, and 21% in Southern Kazakhstan. Promising areas for discovering new deposits include Central and Southern Kazakhstan, the Rudny Altai, and border areas with Russia and China [2]. Currently, increasingly complex and difficult-to-enrich oxidized and mixed ores are being introduced into production, and extracting non-ferrous metals from them presents a technological challenge. Oxidized polymetallic ores are complex ores containing metals such as lead, zinc, copper, and precious metals. They are formed as a result of the weathering of sulfide ores and are characterized by a high content of oxide minerals. Difficult-to-enrich ores represent a significant challenge in ensuring a high level of valuable component extraction and comprehensive utilization. The involvement of oxidized polymetallic ores in processing is an urgent task for the mining and metallurgical industry. These ores are characterized by a complex mineral composition and low reactivity of their valuable components, requiring the development of specialized technologies. To process oxidized polymetallic ores, it is necessary to integrate modern technologies (hydrometallurgy, autoclave leaching, and bioleaching), considering the mineral composition and availability of the ores.