This study examines the impact of regrinding on the interfacial properties of sulfide minerals and the flotation performance of weathered copper–porphyry tailings. The feed material is characterized by a low copper grade (0.17%) and a high proportion of oxidized species (53.84%), which contribute to its inherent chemical stability and poor flotation kinetics. The findings indicate that regrinding serves a dual role: facilitating the liberation of mineral intergrowths and inducing mechanical surface renewal. This renewal is characterized by a significant decrease in the oxidation–reduction potential (ORP) and an intensification of the surface reactivity. Experimental results identify an optimal grinding fineness of 77%–81% passing −0.045 mm, yielding a copper recovery of 16.26% in the absence of a sulfidizing agent. The integration of sodium sulfide (400 g/t) with regrinding significantly enhances recovery to 36.37%, driven by the establishment of a reducing environment (ORP ≈ −150 mV) and the chemisorption-mediated activation of mineral surfaces. While ultrafine grinding (90%–100% passing −0.045 mm) further increases recovery to 51.47%, it is accompanied by deleterious sliming effects and a subsequent loss of process selectivity. The study confirms that mechanical surface rejuvenation and the optimization of electrochemical conditions are critical for improving the processing efficiency of anthropogenic resources, providing a theoretical framework for establishing rational beneficiation regimes.

This study examines the impact of regrinding on the interfacial properties of sulfide minerals and the flotation performance of weathered copper-porphyry tailings. The feed material is characterized by a low copper grade (0.17%) and a high proportion of oxidized species (53.84%), which contributes to its inherent chemical stability and poor flotation kinetics. The findings indicate that regrinding serves a dual role: facilitating the liberation of mineral intergrowths and inducing mechanical surface renewal. This renewal is characterized by a significant decrease in the oxidation-reduction potential (ORP) and an intensification of the surface reactivity. Experimental results identify an optimal grinding fineness of 77-81% passing -0.045 mm, yielding a copper recovery of 16.26% in the absence of a sulfidizing agent. The integration of sodium sulfide (400 g/t) with regrinding significantly enhances recovery to 36.37%, driven by the establishment of a reducing environment (ORP ≈ -150 mV) and the chemisorption-mediated activation of mineral surfaces. While ultrafine grinding (90-100% passing -0.045 mm) further increases recovery to 51.47%, it is accompanied by deleterious sliming effects and a subsequent loss of process selectivity. The study confirms that mechanical surface rejuvenation and the optimization of electrochemical conditions are critical for improving the processing efficiency of anthropogenic resources. providing a theoretical framework for establishing rational beneficiation regimes.

Рассмотрена проблема обогащения лежалых хвостов сложного вещественного состава. Отмечена актуальность регулирования окислительно-востановительного потенциала для вовлечения в валовую переработку сульфидных, смешанных и окисленных частей хвостов. Комплекс проведенных исследований позволил разработать технологические схемы обогащения сульфидных, смешанных и окисленных хвостов на основе регулирования окислительно-востановительного потенциала (далее ОВП). Исследования проведены на окисленной части лежалых хвостов с содержанием меди 0,35% со степенью окисленности 65,52%. Лабораторным экспериментом определено, что для флотации окисленной части хвостов при сульфидизации сернистым натрием требуется выдерживание уровня ОВП -160 мВ. Определение уровня ОВП для окисленной части лежалых хвостов позволит повысить качественно-количественные показатели обогащения, тем самым существенно упростив регулирование процесса Күрделі заттық құрамды қалдықтарды байыту мәселесі қарастырылды. Қалдықтардың сульфидті, аралас және тотыққан бөліктерін жалпы өңдеуге тарту үшін тотығу-тотықсыздану потенциалының деңгейін реттеудің өзектілігі атап өтілді. Жүргізілген зерттеулер кешені тотығу-тотықсыздану потенциалын (бұдан әрі ТТП) реттеу негізінде сульфидті, аралас және тотыққан қалдықтарыды байытудың технологиялық сызбаларын әзірлеуге мүмкіндік берді. Зерттеулер мыс мөлшері 0,35%, тотығу дәрежесі 65,52% болатын қалдықтардың тотыққан бөлігінде жүргізілді. Зертханалық эксперимент натрий сульфидизациясында құйрықтардың тотыққан бөлігін флотациялау үшін OVP -160 МВ деңгейіне төтеп беру қажет екенін анықтады. Жатқан қалдықтардың тотыққан бөлігі үшін ТТП деңгейін анықтау байытудың сапалық және сандық көрсеткіштерін арттыруға мүмкіндік береді, осылайша процесті реттеуді айтарлықтай жеңілдетеді The problem of enrichment of tailings with complex material composition is considered. The relevance of regulation of redox potential for attraction of sulphide, mixed and oxidised tailings into bulk processing is noted. The complex of the conducted researches allowed to develop technological schemes of enrichment of sulphide, mixed and oxidised tailings on the basis of regulation of redox potential (hereinafter referred to as ORP). The studies were carried out on the oxidised part of the overlying tailings with a copper content of 0.35% with an oxidation degree of 65.52%. The laboratory experiment determined that for flotation of the oxidised part of tailings at sulphidisation with sodium sulphide it is required to maintain the ORP level -160 mV. Determination of ORP level for the oxidised part of the tailings will allow to increase qualitative and quantitative indicators of enrichment, thus considerably simplifying the process regulation

This study investigates the effect of preliminary ultrasonic treatment on the flotation recovery of copper from aged tailings of copper porphyry ores. The initial sample was characterized by a low copper content of 0.17%, a high proportion of oxidized copper forms at 53.84%, and fine dissemination of copper-bearing minerals, which complicates their recovery by conventional flotation. Ultrasonic treatment was applied after grinding as a physical method of surface activation. The pulp was treated at a power of 30 W and a frequency of 22 kHz, while the treatment duration varied from 0 to 25 min. The effects of ultrasonic treatment on concentrate yield, copper grade, copper recovery, and enrichment efficiency were evaluated. One-way analysis of variance (ANOVA) was used to assess the statistical significance of the results, and SEM analysis was performed to examine changes in particle surface morphology. The best flotation performance was obtained after 15 min of preliminary ultrasonic treatment. Under these conditions, the copper grade in the concentrate was 1.79 ± 0.06%, copper recovery was 44.37 ± 0.21%, and enrichment efficiency was 40.06 ± 0.38%. Longer treatment times did not improve the results. SEM observations revealed morphological changes consistent with particle disaggregation and possible partial cleaning of mineral surfaces.

This study investigates the effect of preliminary ultrasonic treatment on the flotation re-covery of copper from aged tailings of copper-porphyry ores. The initial sample was char-acterized by a low copper content of 0.17%, a high proportion of oxidized copper forms of 53.84%, and fine dissemination of copper-bearing minerals, which complicates their re-covery by conventional flotation. Ultrasonic treatment was applied after grinding as a physical method of surface activation. The pulp was treated at a power of 30 W and a fre-quency of 22 kHz, while the treatment duration varied from 0 to 25 min. The effects of ul-trasonic treatment on concentrate yield, copper grade, copper recovery, and enrichment efficiency were evaluated. One-way analysis of variance (ANOVA) was used to assess the statistical significance of the results, and SEM analysis was performed to examine changes in particle surface morphology. The best flotation performance was obtained after 15 min of preliminary ultrasonic treatment. Under these conditions, the copper grade in the con-centrate was 1.79 ± 0.06%, copper recovery was 44.37 ± 0.21%, and enrichment efficiency was 40.06 ± 0.38%. Longer treatment times did not improve the results. SEM observations indicated particle disaggregation and partial removal of slime coatings. The results con-firm that preliminary ultrasonic treatment can improve copper flotation from aged tailings.