A cleaner vanadium extraction method featuring non-salt roasting …

Compared to the traditional alkaline salt roasting followed by water leaching process, chromium spinel in the raw vanadium slag will not be converted to carcinogenic chromate salts and exhaust gas will not be produced in the non-salt roasting process. The soluble salt, NH 4 VO 3, can be easily crystallized directly by cooling. The wastewater ...

Comparative study of alkali roasting and leaching of …

Roasted ilmenite samples were treated in a two-stage leaching process, where the first step involved water leaching and this was followed by organic acid …

Transformation mechanism and selective leaching of

The sulfation-roasting-leaching process holds promise as an environmentally friendly method of production but has low recovery efficiency and poor selectivity for Ni and Co in ores containing impurity metals, including Fe, Al, and Cr. In this study, the transformation mechanism and leaching behavior of metals in a limonitic …

A Sustainable Low-Temperature Roasting and Water Leaching Process …

Ocean manganese nodules are rich in Mn, and also contain the strategic metals Cu, Co, and Ni. In this study, a sustainable low-temperature roasting and water leaching process for simultaneously extracting Mn, Cu, Co, and Ni from ocean manganese nodules was proposed. The results show that the primary mineral phase of iron …

Extraction of tellurium and high purity bismuth from

The leaching process of the roasting product was optimized. The optimal water leaching conditions were a liquid to solid ratio of 6:1 and a reaction time of 0.5 h at 25 °C. The optimal alkali leaching condition is 10% NaOH liquid to solid ratio of 6:1 and reaction time of 0.5 h at 25 °C. Tellurium and bismuth were separated, and tellurium was ...

Extraction efficiency of metals from low-nickel matte via NH

Aiming at high energy consumption and large Co loss in the pyrometallurgy of low-nickel matte, a process of NH 4 Cl roasting-water leaching was proposed to co-extract metals, followed by the separation and utilization of metals. The effect of several factors on metal extractions in NH 4 Cl roasting process and the optimized process …

Direct Extraction of Lithium from α-Spodumene by Salt Roasting-Leaching …

The leaching recovery results showed that the order of roasting efficacy of the three reagent categories is Group IA > Group IIA > > NH 4 +. 71 and 88% of water leaching and total leaching recovery values, correspondingly, were achieved by the NaOH roasting-water leaching-acid leaching process, under the nonoptimized conditions of a roasting ...

Direct leach approaches to Platinum Group Metal (PGM) …

This process is a mixed chloride/sulfate based technology, where base metals are removed by sulfuric acid pressure leaching and PGMs are leached after roasting with Cl 2 /HCl as commonly used in PGM refining. However, the solution concentrations of PGMs for the Kell process tend to be lower.

Efficient Extraction of Manganese from Low-Grade Pyrolusite …

In this work, a novel method for extraction of manganese from low-grade pyrolusite by a sawdust pyrolysis reduction roasting-acid leaching process was explored. The reduction roasting was studied systematically, and the mechanism was also explored by thermodynamic and phase change analysis. Results indicate that sawdust was rapidly …

Process study of chloride roasting and water leaching for …

A chlorination roasting-water leaching process to recover Li, Ni, Co, and Mn from spent Li-ion batteries is introduced in this paper. The key parameters were studied and optimized, over 98% of Li, Ni, and Co, and 97% of Mn can be leached out under the most suitable condition of 350 °C roasting temperature, 30 min roasting time, and a 2:1 mass …

Selective recovery of vanadium from high-chromium

High Chrome Vanadium slag requires mechanical activation. ... [10], blank roasting-acid leaching [11], pressure acid leaching [12], and KOH leaching [13]. Currently, the sodium roasting-water leaching process stands as the most mature and commercially viable method for extracting vanadium from chromium-bearing vanadium slag. This …

Highly Efficient Recovery of Vanadium and Chromium: …

of this article was mainly to optimize the leaching conditions of the leaching process of vanadium−chromium residues oxidized with H 2 O 2 in alkaline medium. The optimal …

A novel process of gradient oxidation roasting-acid leaching …

This study focuses on efficient green vanadium extraction of stone coal. A gradient oxidation roasting-acid leaching (GORA) process was proposed, which is additive-free and effectively improves the leaching efficiency with preliminary oxidation and further high-temperature reoxidation. The results of this study showed that 95.59 % of …

Extraction of valuable metals from low-grade nickel

In this process, the nickel matte is roasted first and then followed by leaching in water or acidic medium. A roast-acid leaching process has been developed as a highly effective method for the extraction of valuable metals from low-grade nickel matte, which can recover 94.2% of Ni, 98.1% of Cu, 92.2% of Co and 89.3% of Fe (Geng …

Selective extraction of valuable metals from spent EV …

In summary, a sulfation roasting-two stage leaching process was outlined for the selective extraction of valuable metals from spent EV power batteries. It could be shown that the sulfation roasting treatment allowed the selective extraction of Li by water leaching (Stage 1) and subsequently Ni, Co, and Mn could be efficiently removed by a ...

Decomposition of mixed rare earth concentrate by NaOH roasting …

The rare earth leaching process in the roasted ore is divided into the following six steps. 40, 41, 42 The main influencing factors of the kinetic process of hydrochloric acid leaching roasting ore are the initial HCl concentration and the reaction temperature: 1. H + is transported from the leaching solution to the surface of the solid ...

Development of roasting-acid leaching-magnetic …

The proposed technology includes three steps mainly: roasting, acid leaching, and magnetic separation. The roasting process was conducted in a MAS-II microwave reactor. Firstly, 20 g ore samples were homogeneously mixed with 5% alkali lignin and/or a presetting proportion of Na 2 SO 4, then transferred to a 100 mL …

Extraction of various valuable elements from oceanic

Finally, a comprehensive process flow diagram was summarized for the extraction of various valuable metals from oceanic manganese nodules using the residual carbon roasting-acid leaching process. This research will pave the way for the design of cost-effective and sustainable roasting reductants and reduction roasting processes …

Selective recovery of vanadium from high-chromium

This study employed mechanical activation to enhance vanadium extraction from high chromium-bearing vanadium slag through a low-sodium salt roasting-water …

Pore Evolution in Refractory Gold Ore Formed by Oxidation Roasting …

Refractory gold ore is usually affected by the associated carbonaceous matter through the preg-robbing effect, which is eliminated by oxidation roasting, followed by leaching, to achieve a satisfactory gold leaching efficiency. Roasting–leaching experiments, pore structure measurements, scanning electron microscopy (SEM), and X …

An effective method for directly extracting lithium

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 CaSiO …

Extraction of lithium from coal gangue by a roasting-leaching process …

The relevant factors for alkaline leaching of a technological sample assaying 1.20 % Cu and 0.15 % U were examined using a mixture of Na2CO3/ (NH4) HCO3 solution upon two samples namely; roasted ...

Selective extraction of scandium from bauxite residue

A novel method for selective extraction of scandium from bauxite residue was proposed by ammonium sulfate roasting and water leaching. During the roasting process, ammonium sulfate could selectively react with Sc, Al and Fe in the bauxite residue to produce respective metal ammonium sulfates, and then which were completely …

Study on separation of N, F and Al from hazardous …

The effects of roasting and leaching process on the separation of N, F and Al were studied by roasting leaching experiment, chemical titration, X-ray fluorescence spectroscopy and X-ray diffraction. The purpose is to eliminate the harm of soluble nitrides and fluorides in AD, and to achieve satisfactory aluminum extraction, …

Roasting and leaching behavior of spodumene in sulphuric acid process

The roasting and leaching behavior of spodumene in sulphuric acid process was investigated. Thermal analysis results of ore sample showed that the peak temperature of crystal conversion was 1006 ...

Extraction of lithium from coal gangue by a roasting-leaching process …

Lithium extraction from the coal gangue was systematically investigated via the integrated process of roasting and acid leaching with the mechanism analysis. The majority (94%) of lithium was extracted when raw samples are roasted at 400°C for 20 min before 4 h leaching with 2 mol/L hydrochloric acid at 60°C, which represented the …

Efficient Synchronous Extraction of Nickel, Copper, and …

During the pre–roasting process, commonly the used additives including ammonium chloride 16 – 18, ammonium sulfate 3, 19, 20, sodium sulfate 21, 22 and other roasting additives 23 to enhance the roasting effect. Benefitting from the low-cost, noncorrosive nature, and high metal leaching selectivity of sodium sulfate, it has been considered ...

Leaching of Valuable Elements from the Waste Chromite …

Article Recommendations. ACCESS. ABSTRACT: The efficacious treatment and resource utilization of the chromite ore processing residue (COPR) is important for chromate salt …

Transformation and leaching kinetics of silicon from low …

An alternative process of pre-roasting, phosphoric acid leaching followed by solvent extraction of a limonitic laterite ore was described in this work, with emphasis on the solvent extraction of ...

Energy efficient process for recovery of rare earths from …

An energy-efficient chlorination roasting-water leaching process over conventional oxidation roasting-acid leaching process was developed for the recovery of rare earths from spent NdFeB magnet. Thermodynamic investigation and TG-DTA studies were carried out for the mixture of NdFeB magnet and NH 4 Cl to understand the …

Mineral processing: leaching process of chromium and

Solvent extraction has a wide and well defined use in separation and/or preconcentration of PGMs from ores and solutions [36, 37]. The PGM's were enriched from the water liquor of sodium chromate by solvent extraction using APDC as a chelating agent and methylisobutyl ketone as … See more

Leaching of hexavalent chromium from young chromite ore …

In the roasting process, insoluble trivalent chromium [Cr(III)] present in the ores oxidizes to soluble hexavalent Cr [Cr(VI)], ... Leaching characteristics of the …

Comparative study of alkali roasting and leaching of …

Roasted ilmenite samples were treated in a two-stage leaching process, where the first step involved water leaching and this was followed by organic acid (mixture of 0.25 M oxalic and 0.01 M ascorbic acid) leaching for 2 h, so as to obtain TiO 2-rich residue. During the acid leaching, the leachates were sampled at different times for …

Physical Chemistry of Roasting and Leaching Reactions for …

Traditionally chromium chemical extraction has been carried out with alkali and CaO roasting, which led to major environmental issues due to CaCrO 4 /Na 2 CrO 4 release. In this review we examine the physical chemistry of both the low- and high-temperature roasting processes, which oxidizes the Cr 3+ to Cr 6+ state. Especially, the influence of ...

A review on the roasting-assisted leaching and recovery of …

The typical process route roasting-leaching-precipitation is the most widely used process because of its low cost, simplicity of operation, scalability and high vanadium extraction efficiency. ... Li et al. (2017d) found that the chrome spinel in the original vanadium slag would not be converted into carcinogenic hexavalent chromate during non ...

Leaching of Valuable Elements from the Waste Chromite Ore …

The COPR from the calcium roasting process is the residue of water leaching after mixing chromite, sodium carbonate (Na 2 CO 3), and dolomite and …

Metals | Free Full-Text | Recovery of Gold and Iron from Cyanide

Cyanide tailings are the hazardous waste discharged after gold cyanidation leaching. The recovery of gold and iron from cyanide tailings was investigated with a combined direct reduction roasting and leaching process. The effects of reduction temperature, coal dosage and CaO dosage on gold enrichment into Au-Fe alloy …

Separation of nickel and iron from lateritic ore using a …

The leaching behavior of metals from a limonitic laterite was investigated using a sulfation–roasting–leaching process for the recovery of nickel and cobalt. The ore was mixed with water and ...

(PDF) A clean and efficient method for recovery of vanadium …

the traditional alkaline salts roasting followed by the water leaching process, in the nonsalt roasting process because no additives are added, the chromium spinel in the raw vanadium slag will not be

Nickel carriers in laterite ores and their influence on the …

The solid residue is composed mainly of refractory oxides and water-insoluble oxides such as quartz, alumina, chromite, and hematite. The water used for leaching can be recycled and reused in the process. Sulfation-roasting-leaching basically consists of sulfating the ore sample with concentrated sulfuric acid at room temperature.