the bulk of the world's phosphate reserves is located in sedimentary horizons that contain appreciable amounts of carbonate. during beneficiation of phosphate rocks, huge amounts of oversize phosphate rocks are rejected from crushers. this reject also mostly contains low tricalcium phosphate and high carbonate content. in this study, experiments have been carried out to reduce/eliminate carbona...

Au-Ag noble metal wastes represent a wide range of waste types and forms, with various accompanying metallic elements. The presented leaching strategy for Au-Ag contained in circuit boards (PCBs) aims at gaining gold and silver in the metallic form. Application of the proposed ammonium thiosulphate leaching process for the treatment of the above mentioned Au-Ag containing wastes represents a pr...

In this work, a hydrometallurgical process based on leaching is applied to recover cobalt and lithium from spent lithium ion batteries (LIBs). Citric acid and hydrogen peroxide are introduced as leaching reagents and the leaching of cobalt and lithium with a solution containing C(6)H(8)O(7) x H(2)O is investigated. When both C(6)H(8)O(7) x H(2)O and H(2)O(2) are used an effective recovery of Li...

Remediation of heavy metal polluted sediment by extracting the metals with sulfuric acid can be performed as follows: abiotic suspension leaching, microbial suspension leaching, abiotic solid-bed leaching, and microbial solid-bed leaching. Abiotic leaching means that the acid is directly added, while microbial leaching means that the acid is generated from sulfur by microbes (bioleaching). Thes...

leaching of molybdenite concentrate with hydrogen peroxide in sulfuric acid solution was investigated to determine the effects of reaction time, reaction temperature, h2o2 concentration, h2so4 concentration, pulp density and rotation speed on molybdenum extraction and molybdenite dissolution kinetics, using the taguchi method. from analysis of variance (anova) for molybdenum extraction, the mos...

The main concern of this study is to establish a feasible and an economical method of extracting copper from electronic waste using Aspergillus Niger and Acidithiobacillus Thioxidans. Both Aspergillus Niger and Acidithiobacillus Thioxidans are known to exhibit efficient generation of organic acid and sulfuric acid respectively. To establish their leaching potential, chemical leaching tests usin...

Abstract A novel closed-vessel microwave system for leaching of valuable metals from spent LIBs was examined using ascorbic acid. Important parameters and energy requirement were assessed. Leaching efficiency Li, Co, Mn total decreased as heating rate increased 5 °C/min to 90 °C/min. significantly with increasing acid concentration. temperature 75 °C 125 °C data fitted well pseudo second order ...

The intensification of the thiourea leaching of gold from goldsmith's waste (Košice, Slovakia) using mechanical activation as the pretreatment step. The leaching of “as-received“ sample in an acid thiourea solution resulted in 77 % Au dissolution, after mechanical activation 98 % of the gold was leached during 120 min. The activation was performed in an attritor using variable milling times. Th...

Optimization of the acid leaching process for Mongolian apatite-based ore containing rare-earth elements (REEs) was studied. The ore contained approximately 10% of REEs as total rare earth oxides, and the major impurities were Ca (33% as CaO) and Fe (23% as Fe2O3). Fe bearing minerals could be removed by passing the sample through a wet high-intensity magnetic separator before leaching. After m...

The leaching kinetics of smithsonite ore in acetic acid solutions, an environmental friend, and natural reagent was investigated. The influence of parameters such as reaction temperature, particle size, solid-liquid ratio and acid concentration was studied in order to reveal the leaching kinetics of smithsonite ore. In this study, experimental and statistical methods were carried out in order t...