Two-stage Extraction Research Articles

Effects of extraction methods on morphology, structure and properties of bamboo cellulose

Bamboo cellulose has been widely used as reinforcement for polymers or template material for composites manufacturing due to its high strength-weight ratio and biodegradability. In this work, effects of four extraction methods on the morphology, structure and properties of bamboo cellulose are investigated, including hydrothermal extraction (HT), standard alkali extraction (SA), ambient condition extraction (AC) and two-stage extraction (TS). Among these methods, pure cellulose I with high crystallinity and intact single cell morphology can be obtained by TS. The cellulose extracted by SA have complete cell morphology, mixed structure of cellulose I and II, outstanding toughness and thermal stability. By contrast, there are hemicellulose residues of the cellulose extracted by HT. But it performs better in mechanical properties and thermal stability. The advantage of AC is that the pure cellulose I can be obtained without thermal history, but treatment time is relatively long, resulting in the damage of cellulose morphology.

Recovery of nickel and molybdate from ammoniacal leach liquor of spent hydrodesulfurization catalyst using LIX84 extraction

Ammonia leaching can achieve selective recovery of nickel and molybdenum without aluminum extraction from spent hydrodesulfurization catalyst. In this study, a method for selective nickel extraction by LIX84 from ammoniacal leach liquor is proposed. After a two-stage countercurrent extraction, 99.977% Ni was extracted, while 0.096% Mo, 0.431% Al and 2.812% P were co-extracted under LIX84 concentration of 5%, initial pH value of 11.5, and phase ratio (O/A) of 2/1.1. Then a 0.1 mol/L oxalic acid (initial pH 1.36) was used to strip Ni-loaded organic phase under the phase ratio (O/A) of 0.5. 99.91% nickel in organic phase can be stripped into aqueous phase, while 91.16% nickel in aqueous phase can be precipitated as pure nickel oxalate dihydrate, and the oxalic acid solution containing dissolved nickel can be returned to the next stripping process to achieve nickel recovery. Subsequently, ammonium molybdate product can be obtained from molybdenum-containing raffinate by evaporation and crystallization after impurity removal. In addition, thermodynamic calculations show that the nickel extraction process by LIX84 from ammoniacal solution is an endothermic reaction. The present approach may efficiently be applied to recovery of molybdenum and nickel from spent hydrodesulfurization catalyst as per the proposed schematic flow-sheet.

Sequence of supercritical CO2 extraction and subcritical H2O extraction for the separation of tobacco waste into lipophilic and hydrophilic fractions

A tobacco solid waste was extracted by a sequence of supercritical CO2 (SC-CO2) extraction and subcritical water extraction (SWE). The tobacco waste lipophilic compounds (targeted fatty acids, free base nicotine and VOCs) were extracted using the series of the main operation parameters for the SC-CO2 extraction (pressure: 100–300bar, temperature: 40–80°C). The obtained SC-CO2 extracts were rich in nicotine (0.362–1.585%), neophytadiene (0.082–0.256%) and 4,8,13-duvatriene-1,3-diol (0.144–0.590%). Other VOCs and targeted fatty acids (palmitic, stearic, oleic, linoleic and linolenic) were also determined. Optimized condition for the SC-CO2 extraction of tobacco waste was found at 300bar and 61.22°C. The residues (after SC-CO2 extraction) were re-extracted with SWE under the solvent/solid ratio: 28mL/g, temperature: 150°C, time: 23min. SWE extracts (hydrophilic fractions) were characterized by high concentrations of nicotine (1.61–4.67%), nicotinamide (0.198–0.428%), nicotinic acid (0.118–0.239%), phenolic compounds: chlorogenic acid (0.458–0.740%), 3,4-dihydroxybenzoic acid (0.236–0.403%), neochlorogenic acid (0.240–0.534%), and rutin (0–1.025%). They contained total phenols in the amount 8.03–10.11% and exhibited DPPH antiradical scavenging activity in the range 77.89 to 93.35%. As the results of applied higher temperature 5-HMF (0.076–0.11%), furfural (0.510–0.740%) and 5-MF (0.0292–0.0453%) were also detected in SWE extracts. In some experiments, the obtained values of detected compounds were considerable higher than those obtained from the raw scrap (without SC-CO2 extraction pretreatment) implying that two-stage extraction process (SC-CO2 extraction followed by SWE) can enhance the extraction efficiency due to the elimination of fats during SC-CO2 extraction which enables better dissolution of the other compounds in subcritical H2O.

Solvent extraction of lithium from hydrochloric acid leaching solution of high-alumina coal fly ash

The present work used solvent extraction method to extract lithium from hydrochloric acid leaching solution of high-alumina coal fly ash. In extraction stage, the optimum conditions were explored, at 20 ℃ and O/A = 1:4, using 70%(Vol.) tributyl phosphate-30%(Vol.) sulfonated kerosene-0.36 mol/L Fe3+ as extractant, extraction of lithium could reach 99% by two-stage extraction. In scrubbing stage, 95% of Al3+ in loaded organic phase was scrubbed with 6 mol/L HCl at O/A = 40:1, then 97% of Ca2+ in the loaded organic phase was scrubbed by three-stage countercurrent scrubbing with 5.5 mol/L LiCl + 0.5 mol/L HCl at O/A = 30:1. In stripping stage, 99% of Li+ in scrubbed organic phase was stripped by five-stage countercurrent stripping with 6 mol/L HCl at O/A = 10:1. In regeneration stage, 2 mol/L NaOH was used as regenerant to remove free acid and exchange H+ of extractive compound. There were no third phase, emulsification and solid deposition during the whole experiment. The structure of extractive compound was determined by slope method, and extracted complex ratio of Li+, Fe3+, and TBP was 1:1:1. The extraction process was found to be exothermic and spontaneous by thermodynamic study.Therefore, it’s a promising method to recover lithium from hydrochloric acid leaching solution of high-alumina coal fly ash by TBP-FeCl3-sulfonated kerosene extraction system.

Comparison of the composition and structure for coal-derived and petroleum heavy subfraction by an improved separation method

The property of coal-derived asphaltene and resin shows remarkable differences from petroleum one, such as the molecular aggregation and thermal cracking characteristics. It is significant to make deep-level analysis of their composition and structure to provide detailed molecule information for coal tar deep processing. In this paper, an improved separation method, which innovatively developed two-stage asphaltene extraction and two-stage silica gel separation coupling process, was built to obtain the purified asphaltene and resin components derived from coal tar (C-asp and C-res) and petroleum (P-asp and P-res). All samples were analyzed comparatively through Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), solid state cross polarization/magic angle spinning nuclear magnetic resonance spectroscopy (13C-CP/MAS-NMR), thermogravimetric analysis (TG) and scanning electron microscopy (SEM). It is found that C-asp and C-res contain more OH groups resulting in stronger aggregate effect and OH-OH and OH-ether O are the main hydrogen bond. C-asp and C-res have more C-O of phenols and C = O of COOH group. C-asp and C-res have fewer and shorter alkyl side chains. The aromatic ring substitutive degree (σ) of C-asp and C-res is higher while the alkyl branching degree of P-asp and P-res is higher. Besides, asphaltene has higher σ, alkyl substituents number (n), average stack height of aromatic sheet (Lc), average number of aromatic sheets associated in per stacked cluster (M) and shorter average substituted alkyl chain length (L) compared with resin. Finally, the average molecular structure models of C-asp, P-asp, C-res and P-res are obtained.

A two-stage coupling process for the recovery of base oils from used lubricating oils

This study aims to apply a two-stage solvent extraction and adsorption principles for base oil recovery from used lubricating oils (UBO). Methyl-ethyl ketone was utilized as the solvent for extraction and activated carbon (AC) from unripe plantain peels as the adsorbent. The activities of the solvent to oil proportions from 1:1 to 5:1 on lube oil recovery were analyzed in terms viscosity of the oil, total base number (TBN) of lubricating oil, and percent weight of metallic contents removal from used oil. The results confirm that solvent to oil ratio of 3:1 gave excellent efficiencies relating the UBO to a treated base oil (TBO) with the highest removal of contaminants, increased viscosity, high TBN after the two-stage treatments. The results after solvent extraction at varying temperatures of 30, 45, 60 °C showed the TBN increased to 32% (10.21 mgKOH/g from an initial UBO value of 6.90 mgKOH/g) at 60 °C extraction temperature. After the adsorption stage, the removal of metallic contaminants at the 60 °C extractive temperature and AC 15 wt% loading was 91% for calcium and over 91% for zinc. The optimum solvent to oil ratio of 3:1 at 60 °C yielded a base oil with a kinematic viscosity of 90.23 centiStokes, a flashpoint of 203 °C, the density of 0.909 g/ml and sulphur content of 0.64 wt%. This refined base oil obtained had close similarities with fresh Ram SN500 base oil.

A cleaner strategy for comprehensive recovery of waste SmCo magnets based on deep eutectic solvents

Sustainable and comprehensive recycling of valuable elements from waste SmCo magnets is crucial. In this work, an environmentally friendly process based on low viscosity and easy preparation of hydrophobic deep eutectic solvent (HDES) for comprehensive recovery of Fe(III), Co(II), Cu(II) and Sm(III) from waste SmCo magnets has been developed. The HDESs based on dodecanol (Dodec) and tri-n-octylphosphine oxide (TOPO) were prepared, characterized and first used to selectively extract Fe(III) and Sm(III) from the SmCo magnets leachate. And then the Cu(II) and Co(II) in the raffinate were selectively separated using decanoic acid (DA):lauric acid (LA) (2:1) based HDES. The batch counter current extraction experiment was carried out under optimal conditions. After two-stage extraction by using Dodec:TOPO (2:1) based HDES, over 99% of the Fe(III) and Sm(III) were extracted into the organic phase. Subsequently, the raffinate containing Co(II) and Cu(II) was subjected to single-stage extraction and three-stage scrubbing using DA:LA (2:1) based HDES. Fe(III) and Sm(III) loaded in the Dodec:TOPO (2:1) based HDES phase could be stripped by using 1.5 mol/L H2C2O4. The obtained Fe2(C2O4)3 solution and Sm2(C2O4)3 precipitate were separated by filtration. And the Cu(II) loaded in the DA:LA (2:1) based HDES phase was stripped by using 1 mol/L H2SO4. Finally, Fe(III), Co(II), Cu(II) and Sm(III) were completely separated, and the purity of each product can reach 98.50% or higher. The recovery rates of Fe(III), Co(II), Cu(II) and Sm(III) were 99%, 99%, 96.47% and 99%, respectively. The process has lower chemical consumption and no need to use volatile and toxic organic solvent, which is conducive to cleaner and safer production.

Extraction and analysis of oleanolic acid and ursolic acid from apple processing waste materials using ultrasound-assisted extraction technique combined with high performance liquid chromatography

The aim of the present study was to develop a is simple, effective, eco-friendly, reproducible and high-yield two-stage ultrasound-assisted extraction (UAE) procedure combined with quantitative determination high performance liquid chromatographic (HPLC) method for obtaining isomeric triterpene acids - oleanolic acid (OA) and ursolic acid (UA) in the crystalline dried powdered form from apple processing agro-industrial waste material. A rapid, sensitive and specific HPLC method was developed and validated with respect to robustness, specificity, linearity-range, accuracy, precision and sensitivity. The effect of the nature and the volume of the extraction solvent, the extraction time and the sample size on the extraction efficiency were investigated. The optimal conditions for high-yield extraction were found.

Study on Preparation of Perforated Plate and Biofilm Colonization for Municipal Solid Waste Incineration Fly Ash

At present, municipal solid waste incineration (MSWI) fly ash is mainly based on the solidification agent and then landfilled. How to make the fly ash harmless and reuse it will become an important step in the circular economy. In this study, the fly ash was treated by water extraction and milling to remove the soluble chloride ions and stabilize the heavy metals, and then the perforated plate was prepared by adjusting the composition and sintering technology. Research on biofilm colonization on the perforated plates is expected to achieve the purpose of stabilizing and recycling the fly ash. The fly ash is subjected to a solid-liquid ratio of 1:5 with two-stage water extraction, 2h ball milling, and then mixed at a mass ratio of waste glass powder, Palygorskite powder and the milled fly ash of 7:2:1, and calcined at 850°C for 20 minutes to prepare perforated plate. The results show that the prepared perforated plate has a rough surface, developed internal porosity, and its water absorption rate is 19.5%. The perforated plate is used as the biofilm carrier to be applied to the biological contact oxidation tank, and the natural biofilm colonization method is adopted for the 36-day biofilm culture. The average growth rate of the biofilm on the perforated plate reached 672.22 mg/(L·d), and the maximum microbial biomass was 12.1g/L.

Introducing the metacore concept for multi-target ligand design.

In this work, we introduce the concept of "metacores" (MCs) for the organization of analog series (ASs) and multi-target (MT) ligand design. Generating compounds that are active against distantly related or unrelated targets is a central task in polypharmacology-oriented drug discovery. MCs are obtained by two-stage extraction of structural cores from ASs. The methodology is chemically intuitive and generally applicable. Each MC represents a set of related ASs and a template for the generation of new structures. We have systematically identified ASs that exclusively consisted of analogs with MT activity and determined their target profiles. From these ASs, a large set of 317 structurally diverse MCs was extracted, 127 of which were associated with different target families. The newly generated MCs were characterized and further prioritized on the basis of AS, compound, and target coverage. The analysis indicated that 260 MCs were pharmaceutically relevant. These MCs and the compound and target information they capture are made freely available for medicinal chemistry applications.

Improving technical and economic feasibility of water based anthocyanin recovery from purple corn using staged extraction approach

High anthocyanin concentration in the pericarp, and bioethanol coproduction from remaining fractions make purple corn an attractive source for anthocyanin extraction. Water-based anthocyanin recovery would provide ‘natural’ anthocyanin extract with diverse applications in food industry. However, low anthocyanin recovery with water-based extraction is not economically feasible on a commercial scale. The objective of this study was to investigate various approaches for increasing water-based anthocyanin recovery from purple corn and assessing techno-economic feasibility of these process options for commercial scale application. Anthocyanin recoveries of 48.6, 68.6, 77.9 and 66.8 % with single-stage, two-stage, three-stage, and two-stage countercurrent water-based extractions, respectively, from pericarp, were higher than recoveries (30.8 %) with process conditions used in previous studies. Single-stage extraction with corn flour had 46.1 % higher anthocyanin yield than single-stage extraction with pericarp due to low pericarp yields. Annual ethanol and anthocyanin yields for plants processing 1113 MT purple corn/day were between 35.2 and 36.3 million gal and 496 and 795 MT, respectively for processes modified for water-based anthocyanin extraction, compared to 42 million gal for the conventional process. Capital costs for modified processes ($97.4–101.4 million) were higher than the conventional process ($87.2 million). Due to the high value of anthocyanins, ethanol production costs for modified processes ($0.98 to 0.48/gal) were lower than the conventional process ($1.34/gal). Internal rate of return for modified technologies was 1.9–3.1 times that of the conventional process, indicating an improvement in economic performance. Anthocyanin extraction process with three-stage anthocyanin recovery had the highest profitability among the processes.

Separation of molybdenum and tungsten from iron in hydrochloric-phosphoric acid solutions using solvent extraction with TBP and P507

A mixture of TBP and P507 was proposed for the separation of molybdenum (Mo) and tungsten (W) from iron (Fe) in a hydrochloric-phosphoric acid (HCl-H3PO4) solution that was obtained from the hydrochloric acid preleaching of low-grade scheelite. Various extractants with TBP were investigated, and P507 showed synergistic effects on Mo and W extraction and a strong antagonistic effect on Fe extraction. Then, the effects of various conditions on the separation of Mo and W from Fe with the mixture of TBP and P507 were investigated. Using 24% (v/v) TBP, 16% (v/v) P507 and 60% (v/v) kerosene as extractants, 90% Mo and 88% W were extracted with only 8% Fe co-extraction, and the separation factors of Mo/Fe and W/Fe were 153 and 118, respectively, through one-stage extraction under the following conditions: 1.7 mol/L H+, A/O ratio of 3:1, contact time of 10 min, and temperature of 15 °C. After two-stage batch continuous extraction, 99% Mo, 94% W and 10% Fe were extracted. By washing with 2 mol/L hydrochloric acid, most of the Fe and other impurities were removed with negligible losses of Mo and W. Upon stripping with 5 mol/L ammonia at a 1:1 organic-to-aqueous phase ratio, almost 100% of the Mo and W were recovered from the washed organic phase. Other impurities, such as P, Si, Ca, Al, and Mn, minimally affected the extraction of Mo and W.

An ELM-Based Semi-Supervised Indoor Localization Technique With Clustering Analysis and Feature Extraction

In this article, a new indoor localization technique with extreme learning machine (ELM) is proposed where only a small number of received signal strength indicator (RSSI) measurements are labeled. In the off-line learning phase, the iterative self organizing data analysis techniques algorithm (ISODATA) is used to divide the RSSI measurements into some measurement data subsets. Then the multi-kernel ELM (MK-ELM) method is utilized to perform classification learning and obtain the RSSI measurement classification function. For each RSSI measurement subset, a two-stage feature extraction algorithm using the kernel principal component analysis, the deep learning network and ELM method is proposed for RSSI measurement feature extraction. At last, the position regression function of each subset is obtained by the semi-supervised regression learning. In the on-line position estimation phase, using the measurement classification and feature extraction of the received RSSI measurement, the position is estimated based on the corresponding position regression function. The field tests show that the proposed algorithm can obtain more accurate position estimation than other existing ELM based localization approaches do.

Boron extraction from lithium-rich brine using mixed alcohols

Boron removal from lithium-rich brine was systematically investigated by solvent extraction using 2,2,4-trimethyl-1,3-pentanediol (TMPD) dissolved in 2-ethylhexanol and sulfonated kerosene. The extraction parameters were determined, including the concentration of mixed alcohols, lithium and solvents loss. During the extraction, a single TMPD molecule reacted with a single boric acid molecule to form a complex with two C–O–B ester bonds. The mechanism was also verified using density functional theory (DFT). The overall extraction efficiency reached 99.95% by a two-stage countercurrent extraction. NaOH (0.2 mol/L) with an O/A phase ratio of 1:2 was used to strip the loaded organic phase with 99.99% stripping efficiency. The feasible industrial application of this boron extraction method was validated.

Recovery of metals from spent lithium-ion batteries using ionic liquid [P8888][Oleate

A separation method to selectively recover valuable metals (Co, Ni, Mn and Li) from synthetic spent lithium-ion battery cathodes leachate using a fatty-acid-based ionic liquid, tetraoctylphosphonium oleate [P₈₈₈₈][oleate] is demonstrated. The investigated parameters for this selective separation and recovery process include extraction pH, contact time and composition of the regeneration solution. The benefit of using this ionic liquid is that >99% of Co and >99% of the Mn can be separated from the Ni and the Li by a two-stage extraction process. A subsequent single regeneration process separates the Co from the Mn. Finally, Ni and Li are completely separated in an additional regeneration process. An economic potential analysis concludes the paper, revealing that given the current cobalt price, the process outlined here shows a positive zero-order Economic Potential (bases on product sales and raw material cost) when using a 4 M HCl leaching solution and for leachates containing at least 4.5 g Co per liter.

The potential of polysaccharide extracts from Caulerpa lentillifera waste

Caulerpa is a marine macroalgae and is rich in polysaccharides, which have the potential for immunostimulatory and anticoagulant activity. The objective of this work was to increase the value of C. lentillifera waste by polysaccharide extraction. A polysaccharide yield of about 25% of dry weight was obtained under the following optimized conditions: two-stage extraction (60 min/stage) using a ratio of 1:15 (w/v) at 90 °C, and 2× precipitation by the final concentration of 75% ethanol. The polysaccharide extracts contained a non-reducing sugar that accounted for 44% of weight extracts as a major sugar and consisted of four neutral sugars: mannose (33.3%), galactose (31.9%,), glucose (27.0%) and xylose (7.6%). In addition, it contained sulfate, which is approximately 8.37% of weight extracts and had a phenolic content of around 1.27 mg GAE/g sample. Moreover, it demonstrated α-glucosidase inhibitory activity with an IC50 value of 13.59 mg/mL. This result suggests that the polysaccharide extracts could potentially be used for preventing diabetes disease. The economic analysis also showed an economic feasibility for producing polysaccharide extracts from C. lentillifera waste. This is an alternative for farmers in order to increase the value of C. lentillifera waste.

Extraction of Cobalt and Lithium from Sulfate Solution Using Di(2-ethylhexyl)phosphoric Acid/Kerosene Mixed Extractant

The solvent extraction behavior of cobalt and lithium from mixed sulfate solution using di(2-ethylhexyl)phosphoric acid (D2EHPA)/kerosene as extractant system has been investigated. The effect of different process parameters such as pH of feed solution, extractant concentration, cobalt and lithium ion concentrations in the feed solution have been studied. Extraction equilibrium constants have been calculated and found to be log Kex Co = –2.01 and log Kex Li = –2.42. The highest separation factor of 292 was achieved using 1.59 M D2EHPA at pH 1.85 from mixed sulfate solution. 93.9% of cobalt and 11.4% lithium was co-extracted from 0.01 M cobalt and lithium sulfate solution. Extraction of cobalt-lithium by D2EHPA is affected by cation exchange mechanism, cobalt is extracted as [Co(HA2)2] and [CoA2] depending on the metal concentration in the feed solution while the lithium is extracted as [Li(A2H)]. Quantitative extraction of cobalt was achieved in two-stage counter-current batch extraction (with McCabe–Thiele plot) using 0.477 M D2EHPA at an O : A phase ratio of 1. The data obtained from loaded organic and raffinate indicate a composition which reveals nearly complete extraction of cobalt and rejection of lithium resulting significant separation of these elements from mixed sulfate solution.

Superpixel-based imaging for residential area detection of high spatial resolution remote sensing imagery

The precise and efficient location of residential areas using high spatial resolution remote sensing imagery is a popular research area in the field of Earth observation. Most of the existing approaches are supervised or semisupervised and use data training. Among the unsupervised approaches, corner density-based mapping using kernel density estimate has been widely employed to predict the presence of built-up areas. However, it is computationally time-consuming and the statistical threshold segmentation makes it difficult to obtain a stable and accurate output. To overcome this deficiency, a new two-stage object-oriented residential area extraction scheme was designed. First, a set of corners was extracted using the Gabor filter bank with structural tensor analysis to indicate candidate buildings. Then, instead of pixel units, our method takes superpixel-based image partitions as the primary calculation elements, and an object-oriented weighted sparse spatial voting technique was proposed to accelerate the generation of a residential area presence index. It was demonstrated that the superpixel-based voting strategy was not only efficient in accelerating the calculation process, but it also reduced the false negative rate in the final detection result. Second, a graph-cut method was employed to address the residential area segmentation by integrating a density map as a prior cue that preserves the boundary accuracy better than traditional statistical threshold methods. The effectiveness of the proposed method was evaluated using a series of experiments on the sets of high-resolution Google Earth, IKONOS, and GaoFen-2 (GF2) satellite imagery. The results showed that the proposed approach outperforms the existing algorithms in terms of computational speed and accuracy.

Effect of liquid and air flowrates on the efficiency of a two-stage air-assisted solvent extraction system in pilot scale

Air-assisted solvent extraction (AASX) in continuous-mode is a new development in the solvent extraction process for the extraction of valuable metals from dilute solutions. The main aim of this research was to investigate the effect of the flowrate of liquid and air phases on Cu recovery and organic phase recycling in a two-stage AASX system at pilot scale. The experiments were carried out in continuous-mode and the effect of the flowrates of liquid (18–30 L/min) and air (5–15 L/min for the first stage and 20–40 L/min for the second stage) were evaluated. Response surface methodology was used for designing the experiments, and results were analyzed by the analysis of variance (ANOVA). It was found that increasing the liquid flowrate reduced the Cu recovery in both stages by decreasing the retention time. While, enhancing the air flowrate in the first column increased the Cu recovery and organic phase recycling probably due to the adsorption of uncoated portion of the organic phase and collection of the smaller coated bubbles. Maximum Cu recovery (85%) and organic phase recycling (84%) were achieved at liquid flowrate of 18 L/min, first column aeration of 15 L/min, and second column aeration of 30 L/min for a solution containing 150 mg/L copper. Moreover, 98 and 94% Cu recoveries were obtained for 50 and 100 mg/L Cu solutions, respectively. The results indicated that using the newly developed AASX process, the application of the solvent extraction process could be extended to treat dilute metal-bearing solutions such as acid mine drainage.

Feature extraction on Mueller matrix data for detecting nonporous electrospun fibers based on mutual information

The surface morphology of electrospun fibers largely determines their application scenarios. Conventional scanning electron microscopy is usually used to observe the microstructure of polymer electrospun fibers, which is time consuming and will cause damage to the samples. In this paper, we use backscattering Mueller polarimetry to classify the microstructural features of materials by statistical learning methods. Before feeding the Mueller matrix (MM) data into the classifier, we use a two-stage feature extraction method to find out representative polarization parameters. First, we filter out the irrelevant MM elements according to their characteristic powers measured by mutual information. Then we use Correlation Explanation (CorEx) method to group interdependent elements and extract parameters that represent their relationships in each group. The extracted parameters are evaluated by the random forest classifier in a wrapper forward feature selection way and the results show the effectiveness in classification performance, which also shows the possibility to detect nonporous electrospun fibers automatically in real time.