scholarly journals Extraction of Alumina from Nawan Kaolin by Acid Leaching

2019 ◽  
Vol 35 (3) ◽  
pp. 1013-1021 ◽  
Author(s):  
Mohamed Ahmed Tantawy ◽  
Abdulaziz Ali Alomari
Keyword(s):  
Aluminum Hydroxide ◽  
Acid Leaching ◽  
Liquid Ratio ◽  
Sulfate Ions ◽  
Key Factor ◽  
Sulfuric And Hydrochloric Acids ◽  
Solid Liquid ◽  
Calcined Kaolin

This paper investigated the production of alumina from Nawan kaolin by acid leaching with sulfuric and hydrochloric acids. Kaolin was calcined at 850°C and was leached with 6 M acid at 90°C, 5M NaOH followed by HCl solutions were added to the leaching liquor, and the precipitated aluminum hydroxide was converted to alumina by calcination at 900°C. Materials were characterized by FTIR, XRD, and SEM techniques. The alumina extraction percent was determined at different leaching times (30-180 min) and solid/liquid ratios (0.05-0.15 g/ml). The purity of kaolin is about 95%. The percent of extraction of alumina rapidly increases with the solid/liquid ratio up to 0.1 g/ml then decreases thereafter. The percent of extraction of alumina is higher for HCl than H2SO4. The size of the chloride and sulfate ions is the key factor that controls the percent of extraction of alumina from calcined kaolin under the studied conditions.

Optimization of Nickel Chemical Extraction from Hazardous Residue

2016 ◽  
Vol 14 (1) ◽  
pp. 175-183 ◽  
Author(s):  
Mahdi Gharabaghi ◽  
Amirreza Azadmehr
Keyword(s):  
Reaction Time ◽  
Acid Concentration ◽  
Acid Leaching ◽  
Quadratic Model ◽  
Chemical Extraction ◽  
Liquid Ratio ◽  
Nickel Extraction ◽  
Process Factors ◽  
Solid Liquid ◽  
Significant Factors

AbstractStatistical design of experiments was used for design and analysis of nickel extraction from hazardous waste. Sulphuric acid leaching of zinc plant residue has been performed for monitoring and evaluating the effects of process factors on the nickel leaching yield. Factorial design was planned first in order to study the effect of six process factors and screen main variables. These factors were reaction time, acid concentration, solid-liquid ratio % (w/v), particle size, stirring speed and reaction temperature. The main factors and their interaction were studied by analysis of variance (ANOVA), and the results showed that the reaction time, acid concentration and solid-liquid ratio were the most significant factors. In the second set of experiments, response surface methodology (RSM) was used for modelling and optimisation of significant factors. Quadratic model was derived for the prediction of nickel extraction. The optimum values for maximum nickel was identified to be a leaching time of 30 min, acid concentration 10% (V/V) and solid liquid ratio of 10%. Using these optimum conditions, more than 94% nickel was extracted. In addition the results of model equation showed a good agreement with the experimental data.

scholarly journals Optimization of Nitric Acid Leaching of Rare Earth Elements From Moroccan Natural Phosphate

2020 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Marouane Amine ◽  
Fatima Asafar ◽  
Latifa Bilali ◽  
Mehdi Nadifiyine
Keyword(s):  
Rare Earth ◽  
Nitric Acid ◽  
Rare Earth Elements ◽  
Acid Concentration ◽  
Acid Leaching ◽  
Optimal Conditions ◽  
Liquid Ratio ◽  
Experimental Conditions ◽  
Nitric Acid Leaching ◽  
Solid Liquid

Phosphate is a very important natural resource in Morocco and one of the secondary resources of rare earth elements. Our study is particularly interested in Youssoufia phosphate, which contains 228.77 ppm of rare earth elements (ΣREEs). The purpose of our work is to study the influence of different parameters (acid concentration, solid/liquid ratio and temperature) in order to determine the optimal conditions for the leaching of rare earths. An experimental design (Doehlert matrix) has been drawn up to optimize the experimental conditions of the leaching. All tests were made with nitric acid at different concentrations varying between 1.5M and 4.5M with a solid/liquid ratio of 1/12 to 1/6; reaction temperature and duration are respectively 20°C to 80 °C and 60 min. The optimal conditions are obtained when using 69 °C as temperature, 4.1 M as acid concentration and 1/9 as solid/liquid ratio.

scholarly journals Hydrochloric Acid Leaching Study of Rare Earth Elements from Moroccan Phosphate

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Marouane Amine ◽  
Fatima Asafar ◽  
Latifa Bilali ◽  
Mehdi Nadifiyine
Keyword(s):  
Rare Earth ◽  
Hydrochloric Acid ◽  
Rare Earths ◽  
Major Element ◽  
Acid Leaching ◽  
Optimal Parameters ◽  
Liquid Ratio ◽  
Icp Ms ◽  
Mineral Matrix ◽  
Solid Liquid

As part of the valorization of the Moroccan phosphate rock by extraction of rare earths, different experiments on natural Moroccan phosphate from the Gantour Basin (basin of phosphate in the Youssoufia area) were done in the REMATOP laboratory. The response surface methodology was used to study the effects of the influence of different parameters (acid concentration, solid/liquid ratio, duration of the reaction, stirring speed, and temperature) on the progress of the phosphate rock’s dissolution process to determine the optimal parameters for the extraction of rare earths. The analyses were made at the same time on the mineral matrix and the solutions resulting from the attack of this matrix by different concentrations of hydrochloric acid. The rare earth analyses done by the ICP-MS technique have shown an overall amount of rare earths (ΣREs) of 228.408 ppm with the existence of yttrium as the major element.

scholarly journals Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Marin Ugrina ◽  
Martin Gaberšek ◽  
Aleksandra Daković ◽  
Ivona Nuić
Keyword(s):  
Chemical Modification ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Natural Zeolite ◽  
Contact Time ◽  
Liquid Ratio ◽  
X Ray ◽  
Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

scholarly journals Photodegradation of Phenolic Compounds from Water in the Presence of a Pd-Containing Exhausted Adsorbent

2020 ◽  
Vol 10 (23) ◽  
pp. 8440
Author(s):  
Lavinia Lupa ◽  
Laura Cocheci ◽  
Bogdan Trica ◽  
Adina Coroaba ◽  
Adriana Popa
Keyword(s):  
Phenol Degradation ◽  
Magnesium Silicate ◽  
Degradation Process ◽  
Liquid Ratio ◽  
Phenol Solution ◽  
Secondary Sources ◽  
Great Economic Importance ◽  
Phenol Photodegradation ◽  
Cyphos Il 101 ◽  
Solid Liquid

A closed-cycle technology regarding the use of an exhausted Pd-based adsorbent as a photocatalyst in the degradation process of phenol is presented. Pd (II) represents a precious metal of great economic importance. Its obtained from natural sources become more difficult to achieve. Therefore, also considering the regulations of the “circular economy,” its recovery from secondary sources turn out to be a stringent issue in the last years. Pd(II) ions are removed from aqueous solution through adsorption onto Florisil (an inorganic solid support—magnesium silicate) impregnated with Cyphos IL 101 (trihexyl tetradecyl phosphonium chloride). It was observed that the presence of the ionic liquid (IL) in the adsorbent structure doubles the adsorption efficiency of the studied materials. The newly obtained Pd-based photocatalyst was exhaustively characterized and was used in the degradation process of phenol from aqueous solutions. The phenol degradation process was studied in terms of the nature of the photocatalyst used, time of photodegradation and solid: liquid ratio. It was observed that both the presence of IL and Pd lead to an increase in the efficiency of the phenol degradation process. The new Pd-based photocatalyst could be efficiently used in more cycles of phenol photodegradation processes. When is used as a photocatalyst the Florisil impregnated with IL and loaded with 2 mg/g of Pd, a degree of mineralization of 93.75% is obtained after 180 min of irradiation of a phenol solution having a concentration of 20 mg/L and using a solid:liquid ratio = 1:1.

Research on Ethanol Production by Biological Fermentation of Potato Pulp

2013 ◽  
Vol 805-806 ◽  
pp. 281-285
Author(s):  
Zhong Xu
Keyword(s):  
Chemical Composition ◽  
Ethanol Production ◽  
Production Rate ◽  
Liquid Ratio ◽  
Fermentation Time ◽  
Potato Pulp ◽  
Fermentation Temperature ◽  
Ethanol Production Rate ◽  
Solid Liquid

Bioconversion of potato pulp to fuel ethanol, analysing the potato pulp chemical composition and determining the potato pulp in the role of microorganism produce ethanol under the best conditions is the major research. An analysis of the chemical composition of potato pulp showed that : the basic ingredients are Protein (9.72%), Starch (25.52%), Cellulose (17.90%). The effects of ethanol production rate of solid-liquid ratio, fermentation temperature, inoculumconcertration, fermentation time. The results showed that: the best conditions producting ethanol from potato pulp obtained by single factor experiments are: solid-liquid ratio: 1:15, fermentation temperature: 35°C, inoculumconcertration: 3mL, fermentation time: 20h. Under this occasion, the ethanol production rate was 0.183mL·g-1.

The Influence Factors of Compressive Strength and Production of Mineral Polymer of Aluminum Rocks in Xiuwen County, Guizhou Province, China

2013 ◽  
Vol 690-693 ◽  
pp. 1086-1090
Author(s):  
Jie Zhang ◽  
Qiong Qiong Li ◽  
Yu Qiang Xiong
Keyword(s):  
Compressive Strength ◽  
Water Glass ◽  
Mineral Water ◽  
Raw Materials ◽  
Influence Factors ◽  
Polymer Materials ◽  
Guizhou Province ◽  
Liquid Ratio ◽  
Alkaline Activator ◽  
Solid Liquid

Aluminous rocks from Xiuwen County, Guizhou are the main raw materials, mixed some kaolin mineral. Water glass and alkaline activators are used to product polymer materials, the main experimental indicators are the compressive strength. Here, the studies on amount of water glass and alkaline activator, solid-liquid ratio, amount of kaolin and effects on compressive strength of Geopolymer have been proceeded respectively. The result shows that: the highest compressive strength of geopolymers is17.94 Mpa, with aluminous rock 40g, solid-liquid ratio 2.2, water glass12g and alkali activator 2.01g, as well as kaolin 18.02g.

scholarly journals Modeling of Total Phenolic contents in Various Tea samples by Experimental Design Methods

2018 ◽  
Vol 16 (1) ◽  
pp. 738-744
Author(s):  
Nuraniye Eruygur ◽  
Nazire Gulsah Kutuk Dincel ◽  
Nursah Kutuk
Keyword(s):  
Phenolic Compounds ◽  
Experimental Design ◽  
Green Tea ◽  
Total Phenolic ◽  
Phenolic Substance ◽  
Extraction Temperature ◽  
Liquid Ratio ◽  
Polyphenol Content ◽  
Positive Effects ◽  
Solid Liquid

AbstractTea, from the old ages to the day, is widely consumed both for enjoyment and health care due to its positive effects. The consumption of these products is increasing day by day as a result of the clear presentation of the fact that tea contains high amount of antioxidant substances (such as phenolic compounds), which is important in prevention and treatment of diseases. Tea beverage is a very important source of polyphenols. In this study, phenolic content and antioxidant capacity of different tea species were calculated by modeling with experimental design method. In the experimental part, polyphenol content was determined using the Folin-Ciocalteu method. The total amount of phenolic substance content was examined by Box-Behnken design and response surface method on black tea, green tea and white tea on different extraction temperature, extraction time and solid / liquid ratio. Solid / liquid ratio was found to be the most important parameter in terms of polyphenol content extraction from different tea samples. The highest polyphenol amount (411.762 mg gallic acid / mL) was found in green tea. To the best of our knowledge, this is the first data presenting comparatively study the effect of extraction condition on amounts of phenolic compounds from different tea samples.

scholarly journals Optimisation of the Conversion and Extraction of Arctigenin From Fructus arctii Into Arctiin Using Fungi

2021 ◽  
Vol 12 ◽  
Author(s):  
Zheng Lu ◽  
Bin He ◽  
Jie Chen ◽  
Li-Jun Wu ◽  
Xia-Bing Chen ◽  
...  
Keyword(s):  
Loss Rate ◽  
Aspergillus Awamori ◽  
Liquid Volume ◽  
Average Yield ◽  
Liquid Ratio ◽  
Fermentation Time ◽  
Intestinal Microbes ◽  
Carbon And Nitrogen ◽  
Solid Liquid ◽  
Further Development

Fructus arctii is commonly used in Chinese medicine, and arctiin and arctigenin are its main active ingredients. Arctiin has low bioavailability in the human body and needs to be converted into arctigenin by intestinal microbes before it can be absorbed into the blood. Arctigenin has antiviral, anti-inflammatory, and anti-tumour effects and its development has important value. In this study, we used external microbial fermentation with Aspergillus awamori and Trichoderma reesei to process and convert arctiin from F. arctii powder into arctigenin, hence increasing its bioavailability. We developed a fermentation process by optimising the carbon and nitrogen source/ratio, fermentation time, pH, liquid volume, inoculation volume, and substrate solid-liquid ratio. This allowed for an arctiin conversion rate of 99.84%, and the dissolution rate of the final product was 95.74%, with a loss rate as low as 4.26%. After the fermentation of F. arctii powder, the average yield of arctigenin is 19.51 mg/g. Crude fermented F. arctii extract was purified by silica gel column chromatography, and we observed an arctigenin purity of 99.33%. Our technique effectively converts arctiin and extracts arctigenin from F. arctii and provides a solid basis for further development and industrialisation.

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