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1

A preliminary investigation of dry gravity separation with low specific gravity ores using a laboratory Knelson Concentrator

Zhou Meng, Kökkılıç Ozan, Langlois Raymond, Waters Kristian E.

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 5

art. no. 165992

EN

It has become an active research area for treating low specific gravity (SG) deposits by centrifugal separation due to its high efficiency, low cost and minor environmental impact. Laboratory Knelson Concentrator has shown its potential for processing high density ores on a dry basis. This study investigated the feasibility and the optimum operating conditions when processing a dry low SG feed with a modified Knelson Concentrator. A synthetic mixture of magnetite and quartz with a grade of 1% magnetite was used to mimic a low-density ratio ore. Bowl speed (G), air fluidizing pressure (psi) and solids feed rate (g/min) were chosen as the operating variables. Box-Behnken design was used to design the experiments and response surface method was used for optimization. The effects of each individual factors and their interactions on concentrate grade and magnetite recovery were evaluated. The dry process achieved up to 60 % magnetite recovery with an upgrade ratio of 5. The optimized values for the concentration with the highest recovery and grade of bowl speed, solids feed rate and air fluidizing pressure are 27 G, 200 g/min and 12 psi, respectively.

2

Assay of p-Chlorophenol Compliance Monitoring in Textile Wet Processing Industry Effluent Using Fenton Oxidation Process

Owais Muhammad, Zaidi Asad A., Memon Abdul Hameed, Hussain Ahmad, Ahmed Arsalan

Journal of Ecological Engineering

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2023

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Vol. 24, nr 11

108--116

EN

The textile industries utilize number of dyes, chemicals, and other materials to suffuse the characteristic of fabric qualities. A huge quantity of effluents is produced during the process. However, toxicity from synthetic dyes has become a cause of severe environment concern. Chlorophenols are mostly present in synthetic dyes which are proven carcinogenic and therefore undesirable. A number of techniques were used to remove p-Chlorophenol up to the ZDHC MRSL limit. However, none of them found to be up to mark. Fenton oxidation process was selected for its suitability to degrade the p-Chlorophenol up to 5 ppm or less from the textile wet processing industry effluent. In the present study cotton fiber was selected, as medium considering its common use in textile industry. The impact of Ferrous ion (Fe+2), Hydrogen peroxide (H2O2) and pH on the removal of p-Chlorophenol was examined. The Box-Behnken Design (BBD) of (RSM) was employed to achieve optimum desirable condition for the removal of p-Chlorophenol from effluent. A quadratic model is suggested to relate the independent variables for maximum removal of p-Chlorophenol at the optimal process condition. Results suggest that removal efficiency under the optimum condition [Fe+2] = 6.5×10-3 M, [H2O2] = 2.9×10-2 M, and [pH] = 3.5 was >90% in 15 minutes. It can be summarized that Fenton oxidation process as the promising potential for removal of p-Chlorophenol from textile wet processing industry effluent. This research work helps to address for the general knowledge gap in the textile wet processing industry effluent treatment and provide a plate form for further research.

3

Robust optimization of gradient RP HPLC method for simultaneous determination of ivabradine and its eleven related substances by AQbD approach

Tomić Jovana, Djajić Nevena, Agbaba Danica, Otašević Biljana, Malenović Andjelija, Protić Ana

Acta Chromatographica

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2022

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Vol. 34, no. 1

1--11

EN

This paper is aimed at developing a gradient elution reversed-phase high-performance liquid chromatography (RP-HPLC) method for the separation of a complex mixture composed of ivabradine and its eleven impurities, in a reasonable timeframe. In order to obtain a robust and reliable HPLC method for separation of this mixture, Analytical Quality by Design (AQbD) was applied. This approach demonstrated to be useful in development of a long lasting life cycle methods. Four chromatographic variables were defined as key method parameters (KMPs) and optimized towards the analytical target profile (ATP). Designated KMPs were initial and final amount of acetonitrile in the mobile phase, pH value of the aqueous phase and gradient time, while resolutions of critical peak pairs were denoted as critical method attributes (CMAs). Relationships between KMPs and CMAs were obtained with the aid of Design of Experiments (DoEs) methodology among which Box-Behnken design (BBD) was employed to gain valid mathematical models. Obtained mathematical equations were used to construct the Design Space (DS) and select reliable optimal separation conditions. They included 11% (v/v) and 34% (v/v) of initial and final amount of acetonitrile, respectively, as well as 45 min of gradient elution time and 20 mM ammonium acetate as aqueous mobile phase with pH set to 7.35. The possibility to separate the diastereoisomers of impurity X was also evaluated. It was demonstrated that this separation could not be achieved in gradient elution mode within the defined variable domains and in a reasonable time span. The developed method was validated according to ICH Q2 (R1) guideline and met all the required criteria.

4

Opracowanie składu polepszacza glebowego na bazie bazaltu, biowęgla i otrąb owsianych na plon pszenicy jarej

Sobolczyk-Bednarek Justyna, Choińska-Pulit Anna, Łaba Wojciech

Górnictwo Odkrywkowe

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2021

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R. 62, nr 4

17--27

PL

Praca obejmuje opracowanie różnych wariantów mieszanek polepszacza glebowego i testowania go w glebie, w celu poprawy plonu pszenicy jarej. W badaniach wykorzystano 3-czynnikowy układ doświadczalny według Boxa-Behnkena, w celu modelowania wpływu składników takich jak: biowęgiel, bazalt, otręby pszenne na parametry wzrostu roślin w glebie uniwersalnej. Możliwość zastosowania powyższych składników została potwierdzona poprzez wykonaną wcześniej analizę wieloelementową. Prace badawcze polegały na monitorowaniu tempa wzrostu roślin, badania składu gleby po zakończeniu eksperymentu oraz suchej i mokrej masy roślin po zakończeniu doświadczenia. Badania potwierdziły zasadność stosowania dodatków do gleb, szczególnie jeśli chodzi o otręby pszenne i biowęgiel. Dodatek polepszacza nie wpłynął na zwiększenie zawartości metali ciężkich, co wskazuje na możliwości jego wykorzystania.

EN

The work includes the development of various variants of soil improver mixtures and testing them in soil to improve the yield of spring wheat. The study used a 3-factor experimental system according to Box-Behnken in order to model the influence of components such as: biochar, basalt, wheat bran on plant growth parameters in a substrate based on universal soil. The applicability of the above ingredients has been confirmed by a multi-element analysis performed earlier. The research work consisted in monitoring the plant growth rate, examining the soil composition after the end of the experiment, and the dry and wet mass of plants after the end of the experiment. The research confirmed the legitimacy of the use of soil additives, especially when it comes to wheat bran and biochar. The addition of an improver did not increase the content of heavy metals, which indicates the possibility of their use.

5

Recovery of vanadium and tungsten from spent selective catalytic reduction catalyst by alkaline pressure leaching

Liu Nana, Xu Xinyang, Liu Yuan

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 3

407--420

EN

Improving the efficiency of precious metal recovery from spent Selective Catalytic Reduction (SCR) catalyst provides economic benefits and promises sustainable use of resources. Here we demonstrate highly efficient alkaline pressure leaching method for the extraction of vanadium (V) and tungsten (W) from spent SCR catalyst. We analyzed the effects of experimental parameters such as the stirring speed, leaching agent concentration, leaching temperature, liquid-to-solid ratio, and leaching time. The Box-Behnken design of experiments and the response surface methodology have been employed to understand the impact of the leaching parameters and the impact of their interactions on the leaching rate of V and W. The results showed that the leaching agent concentration significantly promoted the recovery of V and W; the influence of the reaction temperature and leaching time moderately increased the leaching rate of the metals. Moreover, the efficiency of the alkaline pressure leaching technique was determined by the interactions between leaching time and reaction temperature, and the relationships between reaction temperature and leaching agent concentration. By using the response surface methodology, the optimal leaching conditions were found that the leaching agent concentration was 4.75 mol-1, the leaching temperature was 190 °C, and the reaction time was 44.5 min, and the predicted values of V and W leaching rates were 95.76% and 98.36%, respectively. Based on the excellent fitting between modeling and experimental results demonstrated in this work, we conclude that our study can shed light on the development of highly efficient and sustainable metal recovery strategies for practical applications.

6

Investigation and optimization of friction stir welding process parameters of stir cast AA6082/ZrO2/B4C composites

Umar Mohamed J., Palaniappan Pl. K., Maran P., Pandiyarajan R.

Materials Science Poland

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2020

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Vol. 38, No. 4

715--730

EN

In the present investigation, aluminium-based alloy (AA6082) is stir-casted with 3 % ZrO2 and 5 % B4C reinforcement particulates to fabricate Aluminium Metal Matrix Hybrid Composites (AMMHCs) which are further friction-stir welded at different welding conditions to develop a welded joint with optimum ultimate tensile strength (UTS) and microhardness. This newly developed AMMHC will find its specific application as bulkhead partitions in the hull of a ship due to its excellent properties, such as lower weight, higher specific strength, superior resistance to wear, and lower thermal expansion coefficient than that of AA6061 and AA5083 composites. The friction-welded butt joints performance of AA6082/3%ZrO2/5%B4C is generally determined by varying the FSW process parameters such as tool rotational speed (TRS), welding speed (WS), axial load (AL), tool tilt angle (TTA), tool pin profile (TPP), shoulder diameter (SD), etc. In the present work, the empirical relationships are established between parameters highly influencing FSW process (TRS, WS, and AL) and their responses (UTS and weld nugget microhardness (WNH)). The desirability approach is employed for predicting the optimal UTS and WNH. The corresponding values of input process parameters are TRS of 1030.95 rpm, WS of 38.5 mm/min, and AL of 5.88 kN. The calculated UTS and WNH for the present investigation are 239.98 MPa and 94.2 HV, respectively, and these values are consistent with the results of validation experiments.

7

Enzymatic bioconversion of feather waste with keratinases of Bacillus cereus PCM 2849

Ciurko Dominika P., Łaba Wojciech, Piegza Michał, Juszczyk Piotr, Choińska-Pulit Anna, Sobolczyk-Bednarek Justyna

Polish Journal of Chemical Technology

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2019

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Vol. 21, nr 3

53--59

EN

Enzymatic preparation from culture of keratinolytic Bacillus cereus PCM 2849 was applied for hydrolysis of whole chicken feathers, after sulphitolytic pretreatment. This process was optimized using a three-factor Box-Behnken design, where the effect of substrate concentration, sulphite concentration during pretreatment and reaction temperature was evaluated on the release of amino acids. Obtained results revealed the highest impact of reaction temperature, followed by substrate content and sulphite during pretreatment. Optimal process conditions were established, i.e. temperature 44.4°C, feathers 4.7% and treatment with 25.3 mM sulphite. Amino acid composition of the obtained hydrolysate was analyzed. Glutamic acid (9.21 g·kg−1) and proline were dominant, however significant amount of branched-chain amino acids was also observed. The FTIR analysis of residual substrate revealed the cleavage of disulphide bonds in keratin through the presence of thioester residues. The absence of reduced cysteine residues was confirmed, along with minor changes in proportions of keratin substructures.

8

Optimization of Copper Removal by Photovoltaic Electrocoagulation from Aqueous Solution Using Response Surface Methodology Towards Sustainable Development

Thanh Hoa Nguyen, Nguyen Lien, Lan Phuong Dinh Thi

Journal of Ecological Engineering

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2019

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Vol. 20, nr 7

103--111

EN

This research aims at illustrating the optimal functions of removing copper ions in aqueous solution by means of the electrocoagulation process in which portable solar power generators are used as renewable energy. A solar photovoltaic cell (PV), producing approximately 48A current intensity for 4-7 h per day, was sufficient to charge the lithium batteries completely during the day. This system was connected directly to the electrocoagulation tank. The Box-Behnken design (BBD) was applied to evaluate three effects of process factors: current density, the dose of electrolyte (NaCl), and application time. The results showed that an optimal efficiency of 99.01% Cu removal plus an energy savings of 1.039 kWh/m3 were obtained at a current density of 4 A/m2, the dosage of NaCl (electrolyte) of 1.87 g/L, and electrolysis time of 10 min. The chemical components of the sludge produced under these optimized conditions were determined by means of EDX. It was illustrated that the copper ions were the main elements of sludge, and nonhazardous compounds were contained. The PV-lithium battery system is considered to be an efficient alternative energy source toward sustainable development.

9

Optymalizacja mikrofalowo wspomaganej ekstrakcji substancji bioaktywnych z tarczycy bajkalskiej przy użyciu planu doświadczeń Boksa i Behnkena

Cheng L., Yang L.-M., Han M.

Przemysł Chemiczny

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2018

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T. 97, nr 6

921--927

PL

Do optymalizacji parametrów mikrofalowo wspomaganej ekstrakcji MAE (microwave-assisted extraction) flawonoidów z tarczycy bajkalskiej (Scutellaria baicalensis Georgi) zastosowano metodologię powierzchni odpowiedzi opartą na planie Boksa i Behnkena i maksymalizowano wydajność ekstrakcji, traktowaną jako zmienna zależna. Cztery główne składniki ekstraktów (bajkalina, wogonozyd, bajkaleina i wogonina) oznaczano ilościowo metodą wysokorozdzielczej chromatografii cieczowej w celu określenia ich wydajności. Uzyskany wynik porównano z wynikiem uzyskanym metodą ekstrakcji pod refluksem HRE (heat reflux extraction), którą uznano za metodę konwencjonalną. Określono optymalny czas ekstrakcji (3,3 min), optymalną temperaturę ekstrakcji (79°C), optymalny stosunek ciecz-ciało stałe (32,6 mL/g) oraz optymalne stężenie etanolu (66,3%). Po zastosowaniu w doświadczeniach optymalnych parametrów wydajność ekstrakcji wyniosła 19,79±0,16%, i nie różniła się w sposób istotny od wydajności przewidzianej modelem (19,88%). Zastosowanie MAE umożliwiło skrócenie czasu ekstrakcji i zmniejszenie zużycia rozpuszczalnika w porównaniu z HRE. MAE zapewniła większą wydajność flawonoidów i okazała się prostą, skuteczną i perspektywiczną metodą ekstrakcji, przydatną do przemysłowego wykorzystania.

EN

Dry roots of Scutellaria baicalensis Georgi were pulverized and extd. with EtOH under microwaves to recover baicalin, wogonoside, baicalein and wogonin flavonoids. Box-Behnken design model-based response surface method was used to optimize the extn. parameters. The optimum extn. time was 3.3 min, temp. 79°C, liq.-solid ratio 32.6 mL/g and EtOH concn. 66.3%. Under optimum conditions, the yield of flavonoids was 19.79% much higher than that yield under conventional heat reflux conditions.

10

Modelowanie sił w szlifowaniu obwodowym płaszczyzn według różnych planów badawczych

Habrat W., Żółkoś M., Świder J., Socha E.

Mechanik

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2018

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R. 91, nr 10

929--931

PL

W artykule przedstawiono modelowanie sił w procesie szlifowania obwodowego płaszczyzn ze stali 100Cr6 za pomocą ściernicy M3X60K5VE01-35, przeprowadzone z zastosowaniem centralnego planu kompozycyjnego ortogonalnego (CCF) i planu Boxa-Behnkena. Do planowania eksperymentu oraz analizy wyników wykorzystano program Design-Expert. Modele sił uzyskane w ramach wybranych planów porównano na podstawie współczynników determinacji oraz wartości odchylenia standardowego składnika resztowego.

EN

The paper presents forces modeling with the use of DoE models, such as (Box-Wilson) central composite design in face centered variant (CCF) and Box-Behnken design in a surface peripheral grinding process of 100Cr6 steel with M3X60K5VE01-35 grinding wheel. Experiment design and result analysis were done with the use of Design-Expert software. Force models, obtained with application of selected designs of experiment, were compared on the basis of the coefficient of determination, and values of residual standard deviation.

11

Optimization of Operational Parameters of Foam Sizing Process for Cotton Yarns Based on Plackett-Burman Experiment Design

Zhu B., Liu J., Gao W.

Autex Research Journal

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2018

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Vol. 18, no. 1

61--66

EN

This study was aimed at investigating the process optimization of foam sizing for cotton yarns. In this work, effects of major foam-sizing process factors including size concentration, blowing ratio, stirring speed, pre-wetting temperature, pre-drying temperature, squeezing pressure and drying temperature were studied on the hairiness (more than 3 mm) and abrasion resistance of foam-sized yarns. The combination of Plackett-Burman, steepest ascent path analysis and Box-Behnken design were adopted to optimize the foam-sizing process of cotton yarns. Results revealed that size concentration, blowing ratio and squeezing pressure were significant factors that affected the hairiness and abrasion resistance. Optimum hairiness and abrasion resistance were obtained when the cotton yarns were sized at size concentration of 19.33%, blowing ratio of 4.27 and squeezing pressure of 0.78kN. The theoretical values and the observed values were in reasonably good agreement and the deviation was less than 1%. Verifcation and repeated trial results showed that it has good reproducibility and imparts the foam sizing process of cotton yarns.

12

Performance evaluation of chemical coagulation process to treat bagasse wastewater : modeling and optimization

Thirugnanasambandham K., Sivakumar V., Shine K.

Polish Journal of Chemical Technology

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2016

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Vol. 18, nr 1

99--104

EN

In this present study, chemical coagulation process (CC) treatment process was investigated under different conditions such as pH, ferric chloride dose, agitation time and settling time to treat bagasse wastewater using response surface methodology (RSM). The outcomes were evaluated using Pareto analysis of variance (ANOVA) and second order polynomial models were created with the aim of being able to predict the responses. Ideal conditions were observed to be as per the following: agitation time of 25 min, pH of 7, ferric chloride dose of 6 g/L and settling time of 60 min. Under these conditions, turbidity removal of 62%, COD removal of 67%, TDS removal 53% and sludge production of 32 mL/L were obtained with operating cost of 3.50 Rupee/L. The mechanism of CC was analyzed using XRD spectrum and founds to be adsorption.

13

Extraction and optimization of Mucuna pruriens for dyeing of leather

Sundari N.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 2

57--63

EN

The present study reports on the leaching of natural pigment from Mucuna pruriens for dyeing of chrome tanned leather samples. The experiments were performed at temperature (30-70°C), time (30-90 min), feed to solvent ratio (1:3-1:7) and particle size (0.25-0.75 mm) using ethanol as solvent. The influence of process variables on percentage yield has been studied and the conditions were optimized using Box-Behnken design. The optimized conditions for intensified extraction was found to occur at a temperature of 60°C, extraction time of 1 hr, for a feed to solvent ratio of 1:5 and 0.75 mm particle size. The % yield under optimized conditions was found to be 47%. The extraction results were found to agree well with the statistical model (R2 = 0.9740). The colouring ability of extracted dye has been tested on wet blue goat leathers. The dyed leather exhibited a better colour value, strength and fastness properties as inferred from reflectance and visual assessment tests.