an approach to recycle precious metals of cathode materials from spent lithium cobalt oxide batteries by using organic citric acid and hydrogen peroxide has been studied in this paper. the effects of molar ratio, solid-liquid ratio, reaction time and temperature on leaching efficiency of cobalt were investigated respectively. meanwhile the leaching kinetics equation of cobalt was established, a...

Vegetation at mining sites can produce increased heavy metal leaching by the organic acids and protons originating from root secretion and litter degradation. Batch experiments were conducted to investigate the effects of organic acids and pH on the extraction of Pb, Cd, Zn and Cu from an alkaline mine soil (sampled from a mining site of Chenzhou City, Hunan Province) and an acid mine soil (sam...

The removal of heavy metal from sludge before disposal or application to farmland is a necessary step to achieve a more safe sludge usage or disposal. Chemical extraction using inorganic acids (nitric, hydrochloric) and organic acids (citric, oxalic) were tested for extraction of chromium, copper, nickel, lead and zinc from contaminated sewage sludge at different pH and reaction time. Results r...

Leaching properties of Pb, Cd, Zn, Cu at pH of 2-6 using different inorganic acids (hydrochloric acid, sulfuric acid, nitric acid) and organic acids (acetic acids, citric acid, malic acid, succinic acid) aiming at polluted sediment at downstream of a non-ferrous metal smelting enterprise is discussed. Results showed that leaching concentrations of 4 metals decreased with increasing pH. Among al...

Lead citrate is a key precursor for the green recycling of spent lead acid battery paste in a citric acid/sodium citrate (CA/SC) solution. In this study, the main paste component, PbSO4, was leached and crystallized to yield lead citrate. Results showed that the leaching of PbSO4 in citric acid/sodium citrate solution was remarkably enhanced by an increase in temperature from 35 ◦C to 95 ◦C and...

The leaching kinetics of a low-grade zinc oxide ore in different acid media was investigated with respect to the experimental variables including acid concentration, temperature, liquid to solid (L/S) ratio, and stirring speed. The results obtained showed that the leaching reagent concentration and the reaction temperature exerted significant effects on the extraction of zinc, whereas the L/S r...

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...

In this work, we investigated the role of bacteria from the genera Bacillus and Pseudomonas and fungi from the genera Ž . Aspergillus and Penicillium in the leaching process of two different silicates calamine and garnierite . Since the results obtained with A. niger were better than those with different bacteria, a more detailed investigation of the leaching process with this microorganism was...

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...

Leaching of a low-grade lead and zinc oxide ore was studied by an organic reagent, citric acid. The quadratic mathematical models were developed for the relationship among the influential parameters and lead and zinc recoveries. Leaching rate was strongly affected by the interactive effects of factors. It was also found that the quadratic effects of stirring speed and linear<e...