The wide application of chromium will definitely increase the probability of impact of chromium-containing effluents on the surrounding environment and human …
The maximum chromium extraction rate of 91.51% was obtained when soda (Na2CO3) and CCVT were mixed in a molar ratio (n (Na2CO3)/n (Cr2O3)) of 8, roasted at 900 °C and maintained for 120 min.
Sequential designs were used to find satisfactory experimental conditions for chromium recovery from electroplating sludge. A recovery of 97.6% was attained with 30 min contact time and 80% (v/v) HCl (US$ 0.6/L). In every case the leached fluoride levels were high enough to characterize the residuals as dangerous, class 1.
The extraction procedures were completed as mentioned in Section 2.3. 2.4.5. Effect of exposed surface area. The percentage extraction of chromium species in presence of various exposed areas was also studied. Glass substrates with surface areas 19.0, 38.0, 57.0 and 76.0 cm 2 were selected as the deposition surfaces.
Chromium (IV) oxide (CrO 2) is a magnetic compound. Its ideal shape anisotropy, which imparts high coercivity and remnant magnetization, made it a compound superior to γ-Fe 2 O 3. Chromium (IV) oxide is used to manufacture magnetic tape used in high-performance audio tape and standard audio cassettes.
Our scientific research team has developed a process route for the efficient extraction of chromium from chromium-containing feed liquid using amide as the extractant (Ying et al., 2020). In the study, the centrifugal extractor was used to treat the leach liquor of sodium roasting chromite on a pilot scale. The process parameters were …
Under the optimized extraction conditions, a good limit of detection (LOD) equal to 7.0 µg L –1 was achieved for both analytes, while the extraction recoveries for Cr(VI) and Cr(III) were 72% and 84%. In addition, the developed approach was used for the quantification of chromium species in water samples.
Chromium ore processing residue (COPR) is a hazardous waste generated during the production of chromate. Currently, approximately 10% of Cr 2 O 3 cannot be extracted after chromite sodium roasting and remains in COPR, wasting valuable Cr resources. In this study, Mg was selectively removed by using (NH 4) 2 SO 4 roasting in …
Chromium picolinate extraction. Five acetonitrile to water ratios (20:40, 40:60, 60:40, 80:20, and 100:0 ACN:DIW) were tested for the dissolution of the solid CrPic standard. The stock standard preparation was performed using a ultrasonic bath over a period of 40 min. Complete dissolution of the standard occurred at the ratios of 60:40, …
In the industrial production of nickel, cobalt, and scandium, it can also be used to predict the effects of Cr(III) aging and Cr(VI) oxidation on chromium-containing solvent extraction systems and ...
The organic extractant used for copper extraction was 5-20 % v/v LIX 84 diluted in n-heptane, and that for chromium extraction was 30 % v/v TOA (tri-n-octylamine) diluted in xylene.
Shinde and Khopkar [23] studied the extraction of chromium (VI) with 4-methyl-3-pentene-2-one and subsequent determination as its diphenylcarbazide …
Various oxidizing acids with different concentration were used for chromium extraction. Extracted chromium was measured by Atomic Absorption Spectrometry. Recovery of chromium was in the range of …
Chromium extraction and removal study has been carried out by biosorption method. To investigate the effectiveness of water hyacinth roots as a potential biosorbent to remove chromium species from tannery wastewater samples, a series of batch studies were carried out. The various amounts of dried, homogenized, and powdered water …
Moreover, 2.2.1. Extraction of chromium(III) extraction of chromium(III) depends on the concentra- The spent chromium liquors were diluted and alkalized tions and type of electrolytes present in the initial with NaOH, and then immediately used as initial aqueous aqueous phases.
In this study, we incinerated chrome shaving dust at 500oC to 7000C for chromium extraction. Various oxidizing acids with different concentration were used for chromium extraction. Extracted chromium was …
Extraction The methods for producing chromium are similar to those used for other metals. One method ... About 87 percent of chromium used in the United States goes into alloys. The addition of chromium makes the final product harder and more resistant to corrosion. About 70 percent of all chromium is used in the production of stainless steel.
Therefore, the pre-desilication of the chromium-containing slag is highly necessary before chromium extraction and Na 2 CrO 4 production, regardless of which methods are adopted. Among the various techniques for removing silicate mineral, flotation has been recognized as the most economically and widely used method.
The maximum chromium extraction rate of 91.51% was obtained when soda (Na2CO3) and CCVT were mixed in a molar ratio (n (Na2CO3)/n (Cr2O3)) of 8, roasted at 900 °C and maintained for 120 min. Then ...
An extraction efficiency exceeding 97% was reported for the mixed phthalate-thiosalicylate complex. John and Udy" used TBP for the extraction of chromium(III) from perchloric acid medium and reported that hydrolysed species are extracted in this system. According to them CrC104(HZO)s+ is the major constituent of the system at high acidities.
The optimized chromium removal conditions used on this topic are compiled here. Abstract. ... (ILs), is a crucial step in the extraction procedure. Ionic liquids are used in the leaching, electroplating, and liquid-liquid extraction processes. On the other hand, electrochemical techniques have attracted a lot of interest in the treatment of ...
An effective extraction of chromium from SSL slag might be a solution. The conventional industrial process in chromium extraction from chromite involves adding …
Studies on extraction of chromium (VI) from acidic solution by. emulsion liquid membrane. Sekhar Chakraborty, Siddhartha Datt a & Pinaki Bhattacharya. Department of Chemical Engineering, Jadavpur ...
Reagents used for chromium extraction: K 2 HPO 4, Na 3 PO 4, Na 2 CO 3 and EDTA as well as reagents used for spiking of soil CrCl 3 6H 2 O, K 2 Cr 2 O 7 and …
The maximum β V/Cr by pure [C 8 mim][PF 6] was 100.6 in case of pH 3.5.. The extraction mechanism could be the anion exchange between HV 10 O 27 3− and PF 6 −.. A novel approach to prepare ionic liquids with metal oxo-anions as counter anion.. Vanadate-loaded IL phase can be quantitatively stripped by KPF 6 and NaOH.. Pure [C …
Abstract. Chromium (VI) is a widely used industrial chemical, and is generally considered to pose a greatest human health risk because it is more toxic, more soluble, and more mobile than chromium ...
The results demonstrated that 99.67% chromium could be extracted after six-stage countercurrent extraction, almost all impurity ions such as Na, V, Al and Mg could be removed from the loaded ...
Chromium mining involves extracting chromium from underground mines. Chromium is a naturally-occurring element found in rocks, animals, plants, soil, and in volcanic dust and gases. Chromium is mined in two different ways: underground mining and surface mining. Underground mining is used to reach deeper deposits.
The ability of acetic acid to dissolve minerals and, to some extent, metals was reported in a study by Choi et al. (2012), which concluded that wood vinegar can be used to extract chromium, copper ...
Solvent extraction is a mature process for the separation of metal ions from liquid solutions. To recover chromium effectively, it is necessary to use an appropriate ion …
