In the case of HCl, a 3 mol/L acid concentration is needed and addition of an oxidant is required because otherwise 230Th and 226Ra extractions remain poor. ... Extraction of Tungsten, Yttrium, and Uranium from Tantalum—Niobium Ore from Muchinga Province in Zambia ... Y.C., 1982, "The Leaching of Uranium Ore with Emphasis on the Fate of ...
Song et al. (2022) reported for the first time on the leaching of tungsten in tungsten ore processing residue ... A total of 0.2 g of tailings was weighed and digested using a microwave digestion system with HCl–HNO3–HF (6-2-3 mL). The instrument …
A technology has been developed for extracting tungsten from scheelite concentrate with caustic soda by an autoclaving process. In this process, the effects of different variables on the digestion of scheelite, and on the evaporation of the crude sodium tungstate leach solution, has been investigated.The results showed that 98.8% W was …
The main raw materials for tungsten metallurgy are scheelite (CaWO 4) and wolframite [(Fe, Mn)WO 4] (Lassner and Schubert, 1999). Wolframite is decomposed …
Section snippets Acidic decomposition processes producing H 2 WO 4. Three inorganic strong acids, hydrochloric acid (HCl), sulfuric acid (H 2 SO 4), and nitric acid (HNO 3), are the most commonly used reagents for leaching because of their high availability and acceptable price.. The decomposition of scheelite by HCl or HNO 3 …
Both hydrochloric acid and sulfuric acid can be used as a solvent to leach Sc 2 O 3, but there are some disadvantages associated with using ... Liang et al. (2006) extracted most of the W through the same process as used for tungsten ore; leaching by soda under high pressure. Using this method, the content of impurities in the slag can be ...
The aim of this study is to investigate the utility of adding chelating agent during hydrochloric acid leaching of low-grade scheelite concentrates, obtained from Uludağ, Bursa (Türkiye). Examined parameters were as follows; leaching conditions, selective precipitation of tungsten salt from the acidic leach solution in which tungsten …
In this leaching process, the solid film of "tungstic acid" formed, seriously hinders HCl from penetrating into the core of ore, which will lead to a very low leaching yield (Martins et al., 2003, Gao and Su, 1991, Zheng et al., 1980). In order to improve the leaching process and obtain a high yield of tungsten, much more HCl and higher ...
A series of leaching experiments was carried out at different HCl concentration (1.25 to 3.25 M). The other leaching conditions were fixed at 0.4 M H 2 O 2, a solid/liquid ratio of 1:12 at 95 °C for 2 h and an ore grain size of − 200 mesh (− 74 μm). From the obtained leaching efficiencies as shown in Fig. 1, it is clear that as the HCl …
1. Introduction. Tungsten is an essential metal that has been widely used in various fields, such as spatial navigation, electrical engineering, lighting materials, and mechanical manufacturing (Li et al., 2017, Nie et al., 2018).In China, the main economic tungsten minerals with industrial applicability are scheelite and wolframite, and …
Extracting gold from an ore required more reagents and longer retention time because sulphide and gangue minerals consumed sodium hypochlorite and hydrochloric acid. In a leach solution containing 20 % HCl and 20 g/L NaCl, 97 % of the gold was extracted in 6 hours with 90 kg/t available chlorine and 95 % of the gold was extracted in …
With most high-quality tungsten ores being exhausted, the enhancement of low-grade scheelite concentrates processing has attracted a great deal of attention. The objective of this study is to develop a method to maximize the recovery tungsten and molybdenum from a low-grade scheelite via a new acid leaching process followed by …
Synthetic scheelite are considered as an important source of tungsten. In this study, an environment-friendly medium, H 2 SO 4-H 2 O 2 solution, was used to decompose synthetic scheelite. In the leaching process, tungsten was completely dissolved in peroxytungstic acid and separated from the insoluble CaSO 4 ·nH 2 O. The …
Acid leaching is considered an appropriate method for the tungsten concentrate treatment. However, it is difficult to leach wolframite efficiently. To reveal …
As a strategic rare metal, tungsten is widely used in high-performance metallic materials like cemented carbide. The wet decomposition of scheelite CaWO 4 and wolframite (Fe,Mn)WO 4 is the primary and important step in tungsten metallurgy. According to the phase separation behaviors of the decomposition products, the wet …
Acid leaching is considered an appropriate method for the tungsten concentrate treatment. However, it is difficult to leach wolframite efficiently. To reveal the origin of this behavior, the leaching behaviors of scheelite and wolframite in treating a mixed scheelite–wolframite concentrate by hydrochloric acid and the leaching …
The leaching solution was obtained by leaching the tungsten residue in the study with HCl, whose concentration in the leaching solution was controlled at 3.5–4.0 mol/L. Following that, the leaching solution was extracted with HDEHP to remove Sc, Th, U, Zr, and Ti, then with N235 to get rid of Fe, Zn, and Pb.
Acid digestion of tungsten concentrates has attracted more and more attention in recent years, sustainable extraction of tungsten from acid digestion product of tungsten concentrates to obtain (NH 4) 2 WO 4 solution with low impurity content is the key for ammonium paratungstate production. In this work, a process of extracting tungsten …
The decompositions of tungsten ore (CaWO4, FeWO4, and MnWO4) in HCl, HNO3, and H2SO4 solutions occur according to ... A satisfactory tungsten leaching extent of 99.39% was achieved using 10 g/L ...
The kinetics of the leaching reaction of synthetic scheelite with hydrochloric acid was studied to determine the effect of pH and temperature in the formation of tungstic acid.Conversion data obtained from leaching in a temperature range of 28–100 °C and pH between 1.5 and 3.0 are interpreted in terms of the predominating tungsten species …
Then tungsten formations were separated from byproduct MgO and Mg 3 B 2 O 6 in aqueous HCl leaching media. The optimum leaching conditions were obtained at 5.8 M HCl solution, 1/10 S/L ratio, and the temperature of 80 °C for 60 min. The ratio of W 2 B 5 /WB was found to be ∼2.0 containing minor phases of W 2 B and W.
The loss of REEs was controlled below 2.14 wt%. The organic phase can be recycled, and the raffinate with properly prepared pH value can be used for leaching of ion-adsorption type RE ore. This extraction process has shown the application potential for recovering REEs from leaching liquor of ion-adsorption type RE ore.
The extraction of tungsten from scheelite concentrate using phosphoric acid as chelating agent in nitric acid solutions was investigated. The effects of the leaching parameters, such as stirring speed, temperature, concentrations of HNO 3 and H 3 PO 4 as well as particle size were examined in order to model the kinetics of scheelite …
The best results, in terms of tungsten recovery, were obtained under the following conditions; S/L ratio of 1/10, 2 h of leaching period, W/PO 4 3− weight ratio of 7/1, stirring speed of 900 min −1, and HCl concentration of 2 M. NH 4 OH solution was used for precipitating the dissolved tungsten ions as an easily filterable salt. Tungsten ...
The Institute of Metallurgy and Ore Beneficiation, Satbayev University, Almaty 050013, Kazakhstan ... the decrease in the rate constant of hydrochloric acid leaching …
In the initial phase, the focus was on hydrochloric acid concentration, with a fixed time of 16 h at 25 °C. The second phase incorporated the concentration that …
Song et al. (2022) reported for the first time on the leaching of tungsten in tungsten ore processing residue (TOPR), showing that 78% of the active tungsten in …
where m 1 is the mass of the ore (g), w 1 is the mass fraction of tungsten in the ore, c 1 is the concentration of tungsten in the leachate (g·L −1), and ν 1 is the volume of leachate (L). After leaching, the tungsten in the leach solution was extracted and transformed into ammonium tungstate by an ion-exchange method.
[Show full abstract] leaching of nickel and molybdenum reached 92 and 60% respectively, with sodium chlorate consumption of 60 g per 100 g ore and hydrochloric acid consumption of 0·52 mol per ...
Leach solns. were stable when hot and at room temp. in the case of HCl-C2H5OH leaching and only stable when hot in the case of HCl-C2H5OH-H2O leaching. Selective pptn. of tungsten from soln. …
≥90%.23−28 In fact, tungsten compounds cannot be leached in aqueous HCl since tungsten precipitates as H 2 WO 4 on the particle interfaces, limiting the …
where m 1 is the mass of the ore (g), w 1 is the mass fraction of tungsten in the ore, c 1 is the concentration of tungsten in the leachate (g·L −1), and ν 1 is the …
