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the acetoacetic acid were 98.62% and 97.99%, respectively. The optimal acid concentration for the maleic acid-, glycolic acid- and acetoacetic acid-leaching processes were 1, 2 and 1.5 mol l–1, respectively, while their optimal H 2O 2 concentrations were 1.5, 2 and 1.5 vol%, respectively. The optimal solid/liquid ratio, temperature and ...
Then the roasted ore experienced two leaching stages from "hydrochloric acid pre-leaching at 90 °C for 1.5 h" to "intensified sulfuric acid leaching at 300 °C for 1 h". The results show that, the leaching rates of niobium, scandium and rare earth in roasted ore could reach 86.80, 97.42 and 97.94% respectively under the conditions above.
Nickel extractions from the concentrate were very high with almost complete extraction occurring at 85°C (97.6%), however Cu and Co extractions were lower, being only 79.9% and 81.4%, respectively, at 95°C Optimal leaching conditions for metal dissolution were determined to be a temperature of 85°C nitric acid concentration of 6.3 mol/L ...
use of strong acids as leaching reagents can release toxic gases like Cl. 2, SO. 3, and NO. x. during the leach and the waste acid solution after leaching is a threat to the environment [4]. Reduced adverse effects of ... 22.66% respectively. This result is close to the results of research conducted by De Michelis et al.[7] for . 4
The results revealed that the reduction process of cobalt-rich crust was gradually completed from the surface layer of particles to the core. The NaCl and Cu, Co, Ni, and Mn in the roasting residues can be recovered by water leaching and …
Although relatively satisfactory leaching results can be obtained by leaching CAM with acid and reductant, the preparation of CAM is a complicated process. ... added 1 vol% H 2 O 2 at 30 and 60 min respectively (0.5 mol/L citric acid, S/L …
Acidic Leaching. The leaching experiments were performed at atmospheric pressure in 1-liter two-neck Pyrex boiling asks. The mixture was agitated using a magnetic stir - rer at 400 rpm and was heated on a hot plate. For each run of acidic leaching, 100 grams of reduced samples was fed in the setup while maintaining the corresponding parameter
At 20 °C, cobalt recoveries were only 8%, 17% and 12% for citric, malic and aspartic acid leaching, respectively (Fig. 11 a). Leaching efficiency improved with …
A novel method that employs organic acid recovery using citric acid and salicylic acid was used to enhance the leaching of metal ions from the cathode materials of spent LIBs. ... During the leaching reaction, two kinds of leaching acids react with LiCoO 2, respectively. The leaching reaction of LiCoO 2 with citric acid in the presence of H 2 O ...
Alkali-acid. Leaching. Phosphogypsum (PG) is the main by-product of phosphoric acid, which is produced by the sulfuric acid attack of phosphate rocks, wet …
As discussed in subsections "Characterization of synthesized cobalt oxalate" and "Optimization of process variables", the recovery efficiency and purity of cobalt oxalate in acid leaching and acid baking routes are found to be 85.40 and 89.80, and 93.87 and 99.20%, respectively. The variations among the obtained efficiencies and ...
Transformation of ilmenite to different titanium based materials by strong and weak acid, and base digestion, is discussed. Effects of temperature, concentration of acid/base, reaction time on dissolution of ilmenite are extensively reviewed. Characterization of the starting materials, intermediates and the products by x-ray …
The "inorganic acid + reducing agent" system is widely used, but harmful gases will be produced in the process of acid leaching, and the waste acid after leaching is difficult to treat, ... respectively. The leaching reaction of LiCoO 2 with citric acid in the presence of H 2 O 2 can be divided into the following three steps: 30 ...
The first analysis employed a 1-h leaching period, room temperature, 500 g of material, and 1 L of solution, resulting in copper recoveries of 15.49%, 18.84%, 32.82%, and 53.11% for acid concentrations of 40, 60, 80, and 100 kg/t (0.2, 0.3, 0.4, and 0.5 M), …
The NaCl and Cu, Co, Ni, and Mn in the roasting residues can be recovered by water leaching and acid leaching, respectively.
In this study, an ASPEN Plus model in steady state, based on experimental studies, was developed to investigate the leaching behavior of copper and cobalt minerals in sulfuric acid-sodium metabisulfite media. The experimental results indicated that copper and cobalt dissolution efficiencies reach 91 and 72%, respectively. The integration of …
Wet reduction leaching mainly includes cuprous ions reduction-ammonia leaching, ferrous ions reduction-acid leaching ... Cu, Co, Ni, and Fe reached 95.87%, 83.53%, 75.02%, 87.04%, and 35.27%, respectively. After 30 min, the leaching efficiency of the valuable metals no longer increased with the prolongation of leaching time. Hence, …
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acid leaching process for LiCoO 2. Compared to inorganic acids, organic acids are milder with lower acid corrosion and pollution. To date, there have been plenty of reports on the leaching of metal ions from spent LIB cathode materials using organic acids as the leachant, such as succinic acid,16 malic acid,17 aspartic acid,17 citric acid (H 3Cit),
104 t/a, and 0.29×104 t/a, respectively, and the proportions are 77.14%, 75.00%, and 13.12%, respectively. Scandium finally flows into the scandium extraction process is 40.00 t/a, and the proportion is 37.70%. A total of 98.11% of iron and 99.86% of aluminum can be selectively removed by the high-pressure acid leaching. Some recommendations for
Since the acid leaching of the spent cathode powder is usually with the pH value less than 2, the main forms of phosphate in the acid solution should be H3PO4 molecules and H2PO4âˆ' ion indicated by Fig. 4(b). ... The concentrations of Fe and Al in the leachate are 57.67 g/L and 1.43 g/L, respectively. (3) The leaching kinetics of LFP and ...
The research on sulfuric acid leaching of the roasted ore shows that (Na 0.5 Ce 0.3 Ca 0.2)(Ti 0.8 Nb 0.2)O 3 and (Ca 0.7 ... respectively. The leaching residue is leached in concentrated sulfuric acid with an acid-ore of 8:1 (ml/g) at 300 °C for 1 h. The total leaching rates of scandium, rare earth and niobium could reach up to 98.02%, …
The results indicated that for the maleic acid-leaching process, the activation energy of Li and Co leaching was 33.86 and 32.40 kJ mol −1, respectively. For the glycolic acid-leaching process, the …
As a result of leaching, 10–60% of the solid phase was leached, depending on the concentration of sulfuric acid: 0–0.5 mol∙L −1. Leaching with dilute sulfuric acid (0–0.25 mol∙L −1) causes the majority of zinc, up to approx. 90%, to dissolve while maintaining a minimum manganese dissolution, not more than 1%. Increasing the ...
Acid leaching is commonly performed by agitating an ore-leach mixture for 4 to as long as 48 hours at ambient temperature. Except in special circumstances, sulfuric acid is the leachant used; it is supplied in amounts sufficient to obtain a final leach liquor at about pH 1.5. Sulfuric acid leaching circuits commonly employ either
Based on the results in Fig. 2, the leaching efficiencies of Al, Si, and Ti could reach 63.5, 73.9, and 75.6%, respectively, at the condition of 1.0 mol/L oxalic acid with L/S ratio of 15 mL/g at 80 °C for 2 h. These large quantities of Al, Si, and Ti in the Fe-removed leachate justify the efforts for their recovery described below.
The Cr-spinel was too stable to leach out; no more than 8% of the chromium could be leached out both in the direct acid leaching process and calcium-roasting acid-leaching process.
Introduction. Acid rain has been a well-known environmental problem for decades and can lead to acidification of surface waters and soils. Acid deposition is formed from SO 2 and NO x emitted to the atmosphere, largely because of fossil-fuel combustion. The most important sources are energy production, especially coal- and oil-fired power …
They reported that the leaching efficiency values of total rare earth elements were 62.0% and 89.7% for citric and sulfuric acid, respectively. Cánovas et al. [ 27 ] studied the leaching of REEs from PG with nitric and sulfuric acid.
