method leaching acid

However, chemical leaching relying on the additional acid seriously threatens the global environment and nonselective leaching also leads to low Li recovery purity. Here, we first reported a direct electro …

Following rapid thermal processing (RTP), silica is subjected to an acid leaching using an acid mixture solution (AS2) composed of HF (5%):HCl (4%) with a volume fraction of 1:7. During this acid leaching, which was carried out under power ultrasound, an excess of the obtained silica was abundantly dissolved in 10 ml of (AS2) …

Heap Leaching of Uranium. Heap leaching is an extraction process by which chemicals (usually sulfuric acid) are used to extract the economic element from ore which has been mined and placed in piles on the surface. Heap leaching is generally economically …

The main extracting methods discussed in this review are acid and alkaline digestion, and hydrothermal synthesis. Ti based materials of different size, shape and composition synthesized via the above methods or a combination of these methods are reported. ... Tan J. Hydrochloric acid leaching behaviour of mechanically activated …

Waste ash-fishbone was used as a raw material for phosphate extraction using acid leaching process. • The Box-Behnken design was used to optimize P recovery from waste fishbone powder. • 97.5% of phosphate recovery was obtained with 6 M HNO 3. • Electrocoagulation was used to produce iron(III) phosphate(V) from waste ash-fishbone. •

For this reason, a clean method to extract vanadium from the Fe 3− x V x O 4 minerals by single step leaching was proposed in our previous study (Yan et al., 2018, Chen et al., 2020a).In this method, vanadium could be directly leached by oxalic acid synergized with Fe powder under hydrothermal conditions.

Several methods have been used to remove impurities in clay minerals, including acid leaching (Tripathy et al., 2019), alkaline leaching (Li et al., 2019), high pressure (Wu et al., 2012), and ...

A novel method that employs org. acid recovery using citric acid and salicylic acid was used to enhance the leaching of metal ions from the cathode …

Organic and inorganic carbon contents of marine sediments are important to reconstruct marine productivity, global carbon cycle, and climate change. A proper method to separate and determine organic and inorganic carbons is thus of great necessity. Although the best method is still disputable, the acid leaching method is widely used in …

Furthermore, compared with the acid-leaching method, the water-leaching pretreatment method is more environmentally friendly and easier to operate, and hence more widely available. View Show abstract

Acid leaching is the most common method to extract valuable heavy metals for resource recycling and environmental protection. However, the coexisting elements, which are released from electroplating sludge to the leaching solution, will hinder the recycling of valuable heavy metals. In this work, dynamic acid-leaching experiments, X …

open access. •. An environmentally friendly acetic acid leaching process for NdFeB magnets. •. Main effects and interactions of key factors illuminated - flexible …

A comparison between leaching efficiencies of sulfuric acid, nitric acid and hydrochloric acid revealed that H 2 SO 4 had better leaching effect than HNO 3 (Sakultung et al., 2007). HCl can also be used to recover ( Guo et al., 2016 ) lithium and cobalt from spent batteries but the reactions generate toxic gases like Cl 2 which pollute the ...

Acid leaching is the most common method to extract valuable heavy metals for resource recycling and environmental protection. However, the coexisting elements, …

Abstract. Aluminum was leached out from coal fly ash by pressure acid-leaching method. The effects of coal fly ash size, sulfuric acid concentration, reaction time and reaction temperature on extraction efficiency of aluminum were investigated comprehensively. The phase and morphology of coal fly ash and solid residues after …

Thermal activation before the acid leaching step is the oldest pre-treatment method used to produce alumina from non-bauxite ores. Recently, several studies have been carried out for improving the efficiency of the acid leaching process by applying more appropriate and economic stages to the process.

The two widely used methods for zinc recovery are pyrometallurgy and hydrometallurgy but hydrometallurgy is preferred. 11,12 In the first stage of hydrometallurgy, which is leaching, inorganic acids such as sulfuric acid, 10,13,14,15,16,17,18 hydrochloric acid 13,16 and nitric acid 19 were extensively used as a lixiviant in the literature.

The RSM results indicate that the optimum values for those parameters are as follows: temperature 72 ℃, sulfuric acid concentration 1.48 mol/L, oxalic acid concentration 0.96 mol/L, and reaction time 2 h. Under the optimal leaching conditions, the model predicts a maximum leaching yield of 99.5%, compared to the value of 99.1% obtained ...

For this kind of silicon kerf, acid leaching has proven to be an effective method to eliminate metallic impurities in silicon kerf (Kong et al., 2019a; Yang et al., 2019, Yang et al., 2019). However, a significant mass loss occurs during acid leaching process as a result of the extreme small particle size of silicon kerf ( Martins and Margarido ...

To ensure a stable leaching process, the soaking leaching method was used in this experiment to promote the leaching reaction to reach thermodynamic equilibrium within a certain period. Therefore, the leaching capacity of the citric acid leaching system could be determined from the perspective of thermodynamic …

The results of leaching with an eco-friendly organic acid are also presented, along with comparative leaching experiments with other positive electrode materials. …

Metallurgy - Leaching, Extraction, Refining: Oxides are leached with a sulfuric acid or sodium carbonate solvent, while sulfates can be leached with water or sulfuric acid. Ammonium hydroxide is used for native ores, carbonates, and sulfides, and sodium hydroxide is used for oxides. Cyanide solutions are a solvent for the precious metals, …

The alkaline leaching method has the disadvantages of a larger consumption of reagents and lower economic benefits. The extraction rate of lithium in the sulfuric acid method is relatively poor, and the addition of a large amount of fluorine increases the difficulty of subsequent processing. The higher extraction rate of lithium …

In this work, hydrothermal acid-leaching method was used for the recovery of carbon and valuable components in SCC. Through the characterization of raw materials and thermodynamic calculation, the existence forms of various impurities in SCC were clarified, and their reaction characteristics in acid were revealed.

Acid leaching gives higher uranium recovery – 70-90% – compared with 60-70% for alkaline leach, and operating costs are about half those of alkaline leach. Techniques for ISL have evolved to the point where it is a controllable, safe, and environmentally benign method of mining which operates under strict operational and regulatory controls.

A method of roasting-free vanadium recovery from molten vanadium slag via pure oxygen oxidation-assisted acid leaching was investigated in order to implement efficient and green vanadium recovery. The oxidation process of molten vanadium slag discharged from converters by pure oxygen was simulated, and the phase evolution …

In the calcification roasting–acid leaching method, the resulting calcium sulfate leaching residue is difficult to recycle owing to its high sulfur content, resulting in the production of a large amount of solid waste, with a waste yield of 1000%, which occupies valuable land resources (Li and Xie, 2012). Although this method resolves the ...

The aim of this work is the purification of MG-silicon powder using a method combining acid leaching and thermal annealing. It describes experiment carried out by using a tungsten lamps furnace (rapid thermal processing, RTP) to purify silicon powder under controlled atmosphere. This process enables to segregate the impurities to the surface of ...

In this study, a novel lithium extraction method was proposed for α-spodumene by combining activated roasting and sulfuric acid leaching. First, the thermodynamics of the roasting process demonstrated that α -spodumene was converted into β -spodumene, which reacted with CaO to produce acid-soluble LiAlSiO 4 and …

Kumar et al. firstly propose a novel "paste to paste" method based on organic acid leaching followed by calcination process [6, 48, 49]. The spent lead paste is leached by citric acid/sodium citrate or acetic acid/sodium citrate combined with a reducing agent of hydrogen peroxide, from which a lead citrate precursor is obtained [ [50], [51 ...

Due to the suitable leaching efficiency of scandium, it is believed that direct acid leaching with dilute nitric acid is acceptable for RM with a low iron oxide content (less than 30 wt%) . Recently Boyarintsev et al. [ 142 ] evaluated the leaching of scandium from the Russian RM using 2.0 mol/L Na 2 CO 3 under carbonation conditions (CO 2 gas ...

When the acid concentrations exceed 20 wt% or the reaction time closes to 240 min, the leaching rates reach to a saturation value. This is because, with the increasing of reaction temperature, the thermal motion rate of molecules in the solution increases and the increasing HCl concentration is expected to provide more H + in the solution thus ...

Dealkalization is the necessary step for the multipurpose use of red mud (RM), and acid leaching is a productive method to realize the dealkalization of RM. Most researches focus on recovering metals from the highly alkaline waste by pure acid leaching or stabilization by dealkalization. In this study, according to the strong alkalinity of RM …