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1

Struktura i właściwości dielektryczne minerałów ilastych z grupy smektytu

Kułacz Karol, Orzechowski Kazimierz

Wiadomości Chemiczne

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2026

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[Z] 80, 1-2

251--271

EN

Clay minerals are key components of the Earth's surface lithosphere and are naturally occurring nanomaterials that play a crucial role in biological, physical, and chemical processes of soils. This article provides a concise overview of the classification, structure, and properties of clay minerals. It also presents recent results of our research group on their dielectric properties and discusses their potential application as low–cost absorbers of electromagnetic radiation.

2

Dopamine-modified halloysite as new anticancer drug carrier system

Tansik Ecem, Kaplan Can Hatice

Polimery

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2025

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Vol. 70, nr 5

322--330

EN

A new anticancer drug carrier system based on polydopamine-functionalized halloysite (PDA-HNT) was developed. Hansen solubility parameters were used to select 5-fluorouracil (5-FU) as an anticancer drug. The obtained system was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and nuclear magnetic resonance (1H NMR, 19F-NMR). It was shown that PDA-HNT may be a promising drug nanocarrier for delivery systems in cancer therapy.

PL

Opracowano nowy system dostarczania leków przeciwnowotworowych oparty na haloizycie funkcjonalizowanym polidopaminą (PDA-HNT). Na podstawie parametrów rozpuszczalności Hansena jako lek przeciwnowotworowy wybrano 5-fluorouracyl (5-FU). Otrzymany system scharakteryzowano za pomocą spektroskopii w podczerwieni z transformacją Fouriera (FT-IR), spektroskopii fotoelektronów rentgenowskich (XPS), analizy termograwimetrycznej (TGA), magnetycznego 1H- rezonansu jądrowego (1H NMR, 19F-NMR). Wykazano, że PDA-HNT może być obiecującym nanonośnikiem w systemach dostarczania leków w terapii nowotworowej.

3

Fine-size separation of halloysite, kaolinite, and quartz minerals as binary systems using dispersion and sedimentation methods

Durgut Emrah, Çavdar Yunus Emre, Çınar Mustafa, Yavuz Osman, Ozdemir Orhan

Physicochemical Problems of Mineral Processing

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2025

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Vol. 61, iss. 3

art. no. 203225

EN

Clay minerals are mainly composed of aluminum hydrosilicates. In some minerals, aluminum is completely or partially replaced by Fe or Mg. Alkaline minerals or alkali metals are present as major constituents of clay minerals. While some clay sources may contain a single clay mineral, they often contain different minerals such as quartz, calcite, feldspar, pyrite, etc. as impurities. They also contain organic matter and water-soluble salts. Halloysite is a clay mineral belonging to the kaolinite group and USA Environmental Protection Agency (EPA 4A) declared it as an innocuous/adaptable material to human health and the environment. Halloysite ore deposits are mainly found together with kaolinite and quartz minerals, but can also be found as a pure source. The degree of purity of halloysite ore determines the industrial area where it will be used and therefore its economic value. Since clay minerals are naturally composed of fine particles, it is necessary to disperse the clay particles in suspension to separate halloysite and kaolinite minerals. In addition, there are also fine-grained quartz minerals, and to recover pure halloysite minerals, it is necessary to determine their properties in the fine size fraction. In this study, the dispersion properties of halloysite, kaolinite, and quartz minerals in the presence of sodium silicate (SS), sodium tripolyphosphate (STPP), and sodium hexametaphosphate (SHMP) dispersants in fine-size fraction (-38 μm) were researched by particle size measurements and mineral separation properties were investigated by sedimentation experiments at different acidic, neutral, alkaline pH values. In dispersion experiments, the d90 values of halloysite, kaolinite, and quartz minerals were 74.0, 50.7, and 61.3 μm without any dispersant addition, and such values decreased to 54.7, 26.3, and 57.1 μm as SHMP increased to 10 kg/ton, respectively. d50 and d10 values showed a significant change for halloysite, while no important change was observed for kaolinite and halloysite. SHMP had the most effect on the particle size change in the dispersants especially on halloysite minerals. The least effect on particle size change was observed in the quartz sample with dispersant addition. The sedimentation experiments aimed to investigate the effects of pH on halloysite, kaolinite, and quartz recoveries in binary systems as settled products. Kaolinite settled more at acidic pH and halloysite at basic pH. There was no pH-dependent change in the settling behavior for halloysite and quartz. In the quartz-kaolinite system, quartz mineral settled more than kaolinite for all pH values. The settling experiments showed the importance of morphological differences between tubular halloysite and lamellar kaolinite minerals.

4

In2S3/Halloysite Nanocomposite as a Highly Efficient Photocatalyst for Oxidative Desulfurization of Dibenzothiophene in Fuel

Pham Xuan Nui, Tran Viet Hoang, Hoang Phuong Anh, Nguyen T.-Thanh-Bao

Inżynieria Mineralna

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2025

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Vol. 1, no. 2

555--565

EN

Sulfur-containing organic compounds present in transportation fuels such as gasoline and diesel are a major source of environmental pollution, primarily due to the emission of sulfur oxides (SOₓ) during combustion. In response, increasingly stringent global regulations have been implemented to limit sulfur content in fuels. In this study, a nanocomposite photocatalyst composed of indium sulfide (In₂S₃) and halloysite was synthesized via a two-step hydrothermal process. The structural, morphological, and optical properties of the resulting photocatalysts were characterized using X-ray diffraction (XRD), Fouriertransform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS). The photocatalytic performance of the In₂S₃/Halloysite composite was evaluated through the oxidative desulfurization of dibenzothiophene (DBT) under visible light irradiation. Under optimized conditions—reaction temperature of 70 °C, 1.0 mL H₂O₂ as the oxidant, and 40 mg of photocatalyst—the DBT conversion reached 96% after 5 hours. These results highlight the potential application of In₂S₃/Halloysite nanocomposites as efficient visible-light-responsive photocatalysts for sulfur removal from fuels.

5

Effect of blunging process on purification of halloysite ore from ferrous impurities by dry magnetic separation

Durgut Emrah, Çınar Mustafa, Boylu Feridun, Ozdemir Orhan

Physicochemical Problems of Mineral Processing

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2024

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Vol. 60, iss. 2

art. no. 187186

EN

The objective of this research is to study the effects of feed particle size, splitter angle, and washing process on Fe2O3 removal efficiency in the separation of ferrous impurities from halloysite ore by dry magnetic separation in order to increase the purity of halloysite sample after crushing and blunging processes separately. Firstly, after crushing ore in a jaw crusher and sizing to -2+1 mm, -1+0.5 mm, and -0.5+0.212 mm fractions, the sized materials were fed to REMS-type dry magnetic separator at a constant belt speed of 300 rpm with the splitter angles of 0, 15, 30º separately. Maximum Fe2O3 removal efficiency (FRE) (97.1%) was obtained in the nonmagnetic product at -0.5+0.212 mm size fraction and 0º splitter angle. The minimum Fe2O3 content (1.3%) was reached in the nonmagnetic product obtained in the experiment with the feed size of -2+1 mm and a splitter angle of 0º. Secondly, dry magnetic separation was applied to the washed -2+0.212 mm size fraction after drying at room temperature to evaluate the coarse particle-sized halloysite ore that was gained by mechanical dispersion in the aqueous medium towards sodium hexametaphosphate (SHMP), while a significant part of the clay minerals went into fine size after the dispersion process. In the experiment performed with a 0º splitter angle after washing, it was determined that halloysite concentrate of 0.4% Fe2O3 content could be obtained with 98.8% Fe2O3 removal efficiency. As a result of dry magnetic separation experiments, it was seen that Fe2O3 removal efficiency decreased as the splitter angle increased, while Fe2O3 content in magnetic and nonmagnetic products increased. It was determined that washing and cleaning of finesized minerals plastered on particle surfaces after mechanical dispersion and particle release of minerals with different magnetic properties increased the dry magnetic separation efficiency, and nonmagnetic products with very low Fe2O3 (0.4%) and high Al2O3 (31.9%) content was obtained. The blunging process in the presence of dispersant caused the dispersion of clay minerals and allowed to liberating of the ferrous minerals from the halloysite ore, hence the increase in the FRE for the magnetic separation.

6

Green method of conversion of geraniol to value-added products in the presence of selected minerals

Fajdek-Bieda Anna, Wróblewska Agnieszka, Perec Andrzej, Miądlicki Piotr

Polish Journal of Chemical Technology

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2023

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Vol. 25, nr 1

47--60

EN

The study presents the results of research on the process of geraniol (GA) transformation in the presence of natural minerals: montmorillonite, mironekuton, halloysite and also in the presence of halloysite modified with 0.1 M water solution of H2SO4. To obtain information on the structure of the used catalysts, instrumental studies were performed (SEM, XRD, FT-IR, XRF, BET). The second part of the research consisted in examining the influence of individual parameters (temperature, catalyst content, and reaction time) on the course of GA transformation process. The syntheses were carried out without the application of solvent and under atmospheric pressure. To determine the most beneficial process conditions, two functions were selected: GA conversion and selectivity of GA. The proposed method of GA transformation on such minerals: montmorillonite, mironekuton, halloysite, has not been described in the literature so far.

7

Układy hybrydowe na bazie krzemionki i haloizytu do zastosowań środowiskowych i biomedycznych

Kurczewska Joanna

Wiadomości Chemiczne

|

2022

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[Z] 76, 7-8

529--550

EN

Silica and halloysite are inorganic materials of great importance in various areas of industry. Inorganic-organic hybrid systems obtained on their basis allow for the expansion of potential applications to new directions and improve their properties in the context of possible applications. Silica is characterized by good selectivity and mechanical stability. It consists of siloxane and silanol functional groups that can be functionalized with different organic units. Halloysite is an aluminosilicate clay mineral with silica and alumina sheets. It is often characterized by tubular structure, and its internal and external surfaces can be easily functionalized. Two large areas of application for hybrid materials based on silica and halloysite are environmental protection and medicine. Herein, the exemplary materials dedicated to the adsorption of impurities and drug delivery systems are presented.

8

Effect of calcinated halloysite on structure and properties of rigid poly(vinyl chloride) composites

Wieczorek Martina, Tomaszewska Jolanta, Bajda Tomasz, Długosz Jacek

Chemical and Process Engineering

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2022

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Vol. 43, nr 3

383-–404

EN

Halloysite is a filler which may be used to produce composites with thermoplastic polymer matrix. This work summarized the results of investigations of processing, structural, mechanical, and thermal properties of the composites with poly(vinyl chloride) (PVC) matrix and raw halloysite (HA) as well as its calcined product (KHA). The effectiveness of calcination was confirmed with X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption method. The PVC composites with HA as well as KHA were processed in the molten state in the Brabender mixer chamber. The reduction of gelation time and simultaneous increase in maximum torque with filler content were found based on the results of plastographometric analysis. SEM images of PVC/halloysite composites showed a homogeneous distribution of the filler in the polymer matrix. The introduction of halloysite leads to a slight increase in Young’s modulus and tensile strength compared to neat PVC, where the increase of both parameters is greater when KHA is used. The incorporation of 1% KHA led to an increase in impact strength, an effect which may be attributed to toughening of the polymer. A slight improvement of the Vicat softening temperature of 2.7 degrees C for PVC/HA and heat deflection temperature of 2.4 C for PVC/KHA was also ascertained for PVC modified with 10 wt% of filler.

9

Encapsulation of halloysite with sodium alginate and application in the adsorption of copper from rainwater

Marszałek Anna

Archives of Environmental Protection

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2022

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Vol. 48, no. 1

75--82

EN

As part of the work, experiments were carried out on a laboratory scale to assess the effectiveness of the use of composite capsules based on halloysite and sodium alginate for the adsorption of copper from rainwater. The halloysite was subjected to acid activation prior to the encapsulation process. The characteristics of the capsules obtained were determined by means of SEM surface imaging, nitrogen adsorption by the BET method and pHPZC measurement by the suspension method. Adsorption was studied using various operational parameters such as adsorbent dose, contact time, pH and concentration of copper ions in the rainwater. A high percentage of copper ions removal was demonstrated, i.e. 72% for halloysite (H), and 83% for activated halloysite (HA) for a dose of 2.0 g/L. Adsorption of Cu (II) was consistent with pseudo-second order kinetics. The adsorbents showed a high adsorption capacity at the level of 11.03 mg/g, determined by the Langmuir isotherm model. This model fit well with the experimental data.

PL

W ramach pracy przeprowadzono eksperymenty w skali laboratoryjnej mające na celu ocenę efektywności wykorzystania kapsuł kompozytowych na bazie haloizytu i alginianu sodu do adsorpcji miedzi z wód opadowych. Haloizyt został poddany aktywacji kwasem przed procesem enkapsulacji. Charakterystykę otrzymanych kapsułek określono za pomocą obrazowania powierzchni SEM, adsorpcji azotu metodą BET oraz pomiaru pHPZC. Adsorpcję badano za pomocą różnych parametrów operacyjnych, takich jak dawka adsorbentu, czas kontaktu, pH i stężenie jonów miedzi w wodzie deszczowej. Wykazano wysoki procent usuwania jonów miedzi, tj. 72% dla haloizytu (H) i 83% dla haloizytu aktywowanego (HA) dla dawki 2,0 g/L. Adsorpcja Cu (II) była zgodna z kinetyką pseudo drugiego rzędu. Adsorbenty wykazywały wysoką zdolność adsorpcji na poziomie 11,03 mg/g, wyznaczoną za pomocą modelu izoterm Langmuira. Model ten dobrze pasował do danych eksperymentalnych. Stwierdzono, że kapsułki kompozytowe haloizytu i aktywowanego haloizytu mogą być stosowane jako wydajny i tani adsorbent do usuwania miedzi z wody.

10

Sposób wytwarzania recyklatów z produkcji wielowarstwowych membran na bazie polipropylenu oraz ich zastosowanie w osnowie kompozytów z udziałem haloizytu jako napełniacza

Gurdak Daniel, Stachowicz Krzysztof, Androshchuk Dmytro, Pietruszka Weronika, Czaja Krystyna

Przemysł Chemiczny

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2021

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T. 100, nr 6

591--595

PL

Opracowano sposób wytwarzania recyklatów z odpadów membran wielowarstwowych przy ograniczonym wpływie energii cieplnej. Oceniono możliwość wykorzystania otrzymanych recyklatów wraz z pierwotnym polipropylenem do wytwarzania kompozytów z udziałem napełniaczy glinokrzemianowych. Oceniano wpływ udziału recyklatów membranowych oraz haloizytu jako napełniacza na jednorodność otrzymanych materiałów oraz ich właściwości przetwórcze, termiczne i mechaniczne. Najlepszym materiałem okazał się kompozyt z dodatkiem 1% mas. haloizytu zawierający nawet 30% mas. odpadu membranowego. Charakteryzował się on nawet lepszą odpornością termiczną, lepszą udarnością, twardością oraz przetwarzalnością niż odpowiedni kompozyt z udziałem czystej osnowy polipropylenowej.

EN

The waste of multi-layer membranes was thermally stuck together and the obtained tapes were cut into small flakes. The obtained recyclates were used in a mixt. with polypropylene for the production of composites with Al-Si filler. Effect of the content of membrane waste and the halloysite on the homogeneity of the obtained composites and their processing, thermal and mech. properties was analyzed. The best material was a composite with the addn. of 1% by mass of halloysite and up to 30% by mass of membrane waste, which showed better thermal resistance, impact strength, hardness and processability compared to the composite obtained with the pure polypropylene.

11

Sorpcja metali ciężkich na naturalnym haloizycie

Chojnacka Maria, Ligas Bartosz, Kramski Dawid, Warchoł Jolanta

Przemysł Chemiczny

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2021

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T. 100, nr 12

1207--1213

PL

Dokonano przeglądu literatury na temat mechanizmu sorpcji jonów metali ciężkich na naturalnym haloizycie. Omówiono metody modyfikacji haloizytów. Porównano efektywność sorpcji jonów metali na modyfikowanych haloizytach.

EN

A review, with 54 refs., of the mechanism and kinetics of heavy metals sorption onto natural halloysite and methods of modification of halloysite. An impact of the modification on the sorption efficiency was also presented.

12

Protective paints from natural resources : composition and properties

Kugler Szymon, Ossowicz-Rupniewska Paula, Wierzbicka Ewa, Łopiński Jakub

Polimery

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2021

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T. 66, nr 7-8

411--417

EN

Climate changes and increasing cost of non-renewable resources cause the growing interest in technical materials prepared from natural resources. To meet this interest, prototype paints from rosin and bio-diols derivatives, and also halloysite, were formulated to check their thermal, mechanical, visual and functional properties, as protective coatings of steel. Prepared materials contained ca. 75 wt % of natural resources and exhibited considerably better corrosion protection, thermal stability, and also higher glass transition temperatures and hardness, than a commercial petroleum-based reference sample. The other parameters: cross-linking behavior, color, gloss, cupping resistance, adhesion and chemical resistance were within the range that is acceptable for potential users.

PL

Zmiany klimatyczne i rosnące koszty surowców nieodnawialnych powodują zwiększenie zainteresowania materiałami o znaczeniu technicznym, otrzymywanymi z surowców pochodzenia naturalnego. Wychodząc naprzeciw temu zainteresowaniu, opracowano prototypowe farby z pochodnych kalafonii i bio-dioli oraz haloizytu w celu sprawdzenia ich właściwości termicznych, mechanicznych, wizualnych i funkcjonalnych, jako powłok ochronnych dla stali. Przygotowane materiały zawierały ok. 75% mas. surowców naturalnych i wykazywały znacznie lepszą ochronę przed korozją, stabilność termiczną, a także wyższe temperatury zeszklenia i twardość niż komercyjna próbka referencyjna otrzymana z surowców ropopochodnych. Pozostałe parametry: kinetyka sieciowania, kolor, połysk, tłoczność, adhezja i odporność chemiczna, mieściły się w akceptowalnym zakresie dla potencjalnych użytkowników.

13

The Removal of Organic Acids and Aldehydes from Gases Emitted from Composting Municipal Waste

Wierzbińska Monika

Journal of Ecological Engineering

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2021

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Vol. 22, nr 3

58--66

EN

The article describes an experiment conducted under industrial (real) conditions in a municipal waste composting facility. The waste gases emitted from composting processes were passed through an experimental installation built in a semi-technical scale. The installation consisted of two biofilters which were filled with different aluminosilicate beds with average granulation of 4–10 mm. The sorbents were inoculated with a mixture of microorganisms bred on the mineral bed, previously operating in the tank with the waste from that composting facility. Malodorous gases were passed through the installation and concentrations of organic acids and aldehydes before and after passing through biofilters with the examined sorbents. The aim of the experiment was to determine which of the two mineral sorbents better removes the analysed contaminations from post-production gases. The experiment lasted for a month, as difficult and highly variable industrial conditions caused problems with operation and the experiment was suddenly interrupted. The study will be continued after the introduction of design changes in the installation. After the month of conducting the study it can be conclude that in the first weeks of the study, before the dampness of sorbents took place, halloysite reduced the concentrations of acetic acid in 80–99%, and of acetaldehyde in 96–98%. The other aluminosilicate caused a drop in the concentrations by 97–98% and 92–86%, respectively. Moreover, in the experiment planned in the semi-technical scale, it was not possible to determine the overall performances of mineral biofilters due to unstable operating conditions and ending the experiment prematurely. The halloysite sorbent finally turned out to be potentially the more efficient than the other aluminosilicate sorbent.

14

The Application of Mineral Sorbents to Remove Volatile Organic Compounds from the Gases Emitted from the Composting Processes

Wierzbińska Monika

Journal of Ecological Engineering

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2021

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Vol. 22, nr 2

98--110

EN

The disposal of organic waste in processes such as composting is related to the emission of malodorous compounds. Owing to their character and low odour detection threshold, there is often a need for a hundred percent elimination of the contaminants from waste gases. One of alternative methods of treating the waste gases from malodorous contaminants, occurring in low concentrations in post-process air, is the biofiltration method. Most often, the method uses an organic filtration material. However, this method of air purification is still developing; therefore, there is a search for new sorbents among mineral materials, which would be an alternative for organic sorbents. The article presents the research into the application of aluminosilicate sorbents, including halloysite, for deodorization of the gases emitted from the processes of composting municipal waste. The semitechnical scale research was conducted for several weeks in a municipal waste composting plant, passing real gases through two biofilters filled with mineral sorbents. In spite of the fact that some problems occurred and the research cycle was not completed, the experiment proved that halloysite removes odours to a much higher extent than the other examined aluminosilicate sorbent. While the VOCs reduction on a bed with halloysite was 88%, the reduction on a bed with a second aluminosilicate reached 35%. The process conditions were very unstable; therefore, the efficiency of the VOCs removal process varied widely. However, halloysite has always been a better sorbent than the other aluminosilicate.

15

Wykorzystanie haloizytu w układach izolacyjnych

Gryzło Katarzyna, Górecki Lech, Halama Agnieszka

Inżynieria Elektryczna

|

2021

|

nr 8

10--11

PL

Napełniaczem, który stał się ostatnio przedmiotem badań wdrożeniowych wielu ośrodków badawczych, jest haloizyt. Minerał ten jest przedmiotem intensywnych badań nad możliwością zastosowania go w kompozytach polimerowych w celu poprawy ich właściwości. Użycie haloizytu do modyfikacji jest prostsze i tańsze niż w przypadku np. montmorylonitu, miki czy kaolinu. Łatwiej i szybciej można go też rozdrabniać i dyspergować.

16

Haloizyt jako napełniacz lakierów elektroizolacyjnych

Halama Agnieszka, Górecki Lech, Gryzło Katarzyna

Inżynieria Elektryczna

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2021

|

nr 6

40--43

PL

Właściwości kompozytów polimerowych w istotny sposób zależą od zastosowanego napełniacza, jego budowy, kształtu i wielkości. Poszukiwane są tanie napełniacze, które obok poprawy właściwości w istotny sposób nie wpłyną na cenę wyrobów gotowych. Mineralne napełniacze warstwowe, takie jak: węglan wapnia, talk, kaolin, wollastonit, siarczan baru, kwarc czy napełniacze na bazie montmorylonitu ze względu na swe cechy fizykochemiczne i niską cenę zyskały w ostatnich latach dużą popularność na rynku tworzyw kompozytowych. Napełniaczem, który stał się ostatnio przedmiotem badań wdrożeniowych wielu ośrodków na całym świecie, jest haloizyt. W ostatnich latach ukazało się ponad 600 fachowych publikacji na ten temat, a w USA jest on już oferowany jako handlowy napełniacz do przemysłowego zastosowania dla określonej grupy polimerów: Dragonit [1] i Pleximer [2].

17

Wpływ dodatków paliwowych na emisję tlenków azotu przy spalaniu biomasy agrarnej

Sobieraj Jakub, Kalisz Sylwester

Instal

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2021

|

nr 3

22--25

PL

Praca przedstawia analizę wpływu dodatków paliwowych na emisję tlenków azotu z procesu spalania biomasy w laboratoryjnym piecu rurowym. Analiza wykonana została dla dwóch udziałów masowych, dwóch glinokrzemianów z grupy kaolinitu – kaolinu oraz haloizytu. Oba glinokrzemiany są przedmiotem badań naukowców z Politechniki Śląskiej jako substancje wpływające pozytywnie na proces spalania, tj. zmniejszające zanieczyszczanie powierzchni ogrzewalnych kotła, a także poprawiające jakość UPS – Ubocznych Produktów Spalania, do których zaliczany jest popiół lotny. Ten ostatni fakt jest o tyle istotny, że w obecnej sytuacji, w której obszarem priorytetowym staje się Gospodarka Obiegu Zamkniętego, popioły stanowią potencjalne źródło surowca, który jeszcze niedawno uznawany był za odpad, a spektrum jego ponownego wykorzystania było dość wąskie. Analiza ta ma na celu laboratoryjne sprawdzenie wpływu zastosowania addytywów na emisję NOx przy spalaniu biomasy i wynika z niejednoznacznych obserwacji dokonanych podczas badań wpływu addytywów na inne własności procesu spalania. Zaobserwowano wówczas, że jedynym negatywnym wpływem zastosowania glinokrzemianów jest nieznaczne zwiększenie emisji NOx. Niniejsza praca uściśla te obserwacje.

EN

This paper presents an analysis of the effect of fuel additives on nitrogen oxide emissions from biomass combustion in a laboratory tube furnace. The analysis was performed for two mass fractions, i.e. two aluminosilicate minerals from kaolinite group – kaolin and halloysite. Both aluminosilicates are the subject of research carried out by scientists from the Silesian University of Technology as substances that have a positive effect on the combustion process, i.e. reduce the fouling effect in the boiler heating surfaces and improve the quality of combustion by-products of, which include fly ash. It is very important because while the Circular Economy is becoming a priority area, ash is a potential source of raw material that until recently was considered as waste and the spectrum of its reuse was quite narrow. This analysis is intended as a laboratory test of the effect of the use of additives on NOx emissions from biomass combustion and stems from the inconclusive observations made when studying the effect of additives on other properties of the combustion process. It was observed then that the only negative effect of using aluminosilicates was a slight increase in NOx emissions. The present work clarifies these observations.

18

The composting of PLA/HNT biodegradable composites as an eco-approach to the sustainability

Czarnecka-Komorowska Dorota, Bryll Katarzyna, Kostecka Ewelina, Tomasik Malgorzata, Piesowicz Elżbieta, Gawdzińska Katarzyna

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2021

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Vol. 69, nr 2

art. no. e136720

EN

The article presents the results of the research related to the decomposition of polylactic acid (PLA)/halloysite nanotube (HNTs) biocomposites into a simple organic form. After manufacturing the nanocomposites, the evaluation of the composting process simulation was conducted using the biodegradation method. First, the selected properties of PLA/HNTs biocomposites, such as density, water absorption, and impact strength were tested. Next, the impact of the composting process on the behavior of PLA/HNTs composites was investigated from 30 to 90 days. Finally, the loss of mass of the composites, hardness, and the structural changes of biocomposites under the composting conditions before and after the composting were evaluated using SEM microscopy. The results showed that the PLA modified by HNT particles has biodegradation-friendly properties and therein is fully suitable for organic recycling. Due to this, in the coming years, it may contribute to the replacement of non-biodegradability polymers, i.e. polyolefins and polyesters, and reduction of plastic packaging wastes.

19

Thermal characterization of halloysite materials for porous ceramic preforms

Kujawa M., Suwak R., Dobrzański L.A., Gerle A., Tomiczek B.

Archives of Materials Science and Engineering

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2021

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Vol. 107, nr 1

5--15

EN

Purpose: The aim of the study was to investigate the possibility of sintering raw (natural) halloysite and pure halloysite to produce porous ceramic preforms, and determination of sintering temperature based on the results of investigations into thermal effects, linear changes and phase transitions. Design/methodology/approach: Due to mullitisation ability of halloysite at high temperature, alternative applications based on the sintering technology (including the production of reinforcement of metal matrix composites) are being searched for. Pure halloysite and Dunino halloysite were selected for the study. Findings: Pure halloysite, characterized by low impurities, dimensional stability during sintering, softening temperature above 1500ºC and ability to transform into mullite at temperatures above 950ºC could be used as a base for the production of sintered, porous mullite preforms. Research limitations/implications: Presence of impurities in Dunino halloysite, contribute to the shift of the sintering temperature towards lower temperatures and caused a rapid and uncontrolled shrinkage of the sample and the appearance of the softening temperature at 1300ºC. Practical implications: Based on the research of thermal (DTA/TG, linear changes in high-temperature microscopy) and XRD studies it is possible to determine the sintering temperature of pure halloysite to manufacture the porous mullite preforms with open porosity. Originality/value: The received results show the possibility of obtaining the new mullite preforms based on pure halloysite.

20

Zastosowanie sorbentu haloizytowego do usuwania syntetycznych barwników azowych Acid Red 27 i Reactive Black 5 z roztworów wodnych

Sakiewicz Piotr, Piotrowski Krzysztof, Boryń Dominika, Kruk Milena, Mścichecka Joanna, Korus Irena, Barbusiński Krzysztof

Przemysł Chemiczny

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2020

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T. 99, nr 8

1142--1148

PL

Badano proces adsorpcji syntetycznych barwników azowych Acid Red 27 i Reactive Black 5 z roztworów wodnych z zastosowaniem krajowego haloizytu ze złoża Dunino koło Legnicy, poddanego różnym procesom przygotowania wstępnego. Suszony haloizyt wykazywał lepsze zdolności adsorpcyjne w stosunku do obu barwników niż haloizyt kalcynowany. Możliwości usuwania barwników azowych z roztworu wodnego zależą od wstępnego przygotowania haloizytu (suszenie, kalcynacja, rozdrabnianie), jego klasy ziarnowej, jak również od początkowego stężenia barwnika w oczyszczanym roztworze. Określono wartości parametrów izoterm adsorpcji Langmuira i Freundlicha oraz modeli kinetyki pseudo-pierwszorzędowej i pseudo-drugorzędowej dla badanych układów procesowych.

EN

Two com. azo dyes were removed from aq. solns. by adsorption on a Polish raw halloysite. The dried halloysite samples showed better adsorption efficiency in respect to both dyes than the calcined ones. Sepn. abilities of the azo dyes depended on the preliminary pretreatment of raw halloysite (drying, calcination, milling), size class of the adsorbent fraction used, as well as on the initial concn. of the dye in the soln. The parameters of Langmuir and Freundlich adsorption isotherms, as well as of pseudo-first-order and pseudo-second-order kinetic models for the systems were detd.