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1

Przyszłość polskich desulfogipsów z odsiarczania spalin metodą mokrą wapienną w świetle krajowej polityki klimatyczno-energetycznej – przegląd

Haba Sylwester, Nocuń-Wczelik Wiesława

Materiały Ceramiczne

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2021

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T. 73, nr 1

3--13

PL

Praca poświęcona jest problemowi surowców zawierających siarczan(VI) wapnia o różnym stopniu uwodnienia, stosowanych w produkcji wielu materiałów budowlanych: nowoczesnych spoiw, prefabrykatów i cementu. Od około 30 lat w Polsce najważniejszym źródłem siarczanu wapnia jest gips syntetyczny pochodzący z procesu odsiarczania gazów odlotowych w energetyce. Prognozy pozyskania tego materiału są ściśle związane z polityką energetyczną, która w trosce o rozumianą szeroko jakość powietrza i klimat, stawia za cel odejście od paliw kopalnych. W pracy przedstawiono relacje ilościowe pomiędzy różnymi rodzajami surowców siarczanowych, metody i produkty odsiarczania, jak również symulacje dotyczące podaży tych materiałów w nawiązaniu do uwarunkowań środowiskowych i prawnych w Unii Europejskiej w perspektywie najbliższych dekad.

EN

The calcium sulphates of different constitutional water content are the base raw materials used in the production of numerous building materials, such as modern binders, prefabricated wallboard elements and cement. In Poland, the synthetic gypsum, resulted from the wet process of flue gas desulphurization in thermal power plants, has been the most important source of calcium sulphate for around 30 years. The synthetic gypsum is generated in a close relation to the energy policy which nowadays is focused on the air quality and problems of climate changes. The reduction of fossil fuels consumption is therefore a main goal. In this work, the evolution of volume ratio concerning different calcium sulphate sources based upon the environmental policy and rules in the European Community in the nearest decades are discussed.

2

Comparative study on physicochemical properties of alpha-TCP / calcium sulphate dihydrate biomicroconcretes containing chitosan, sodium alginate or methylcellulose

Czechowska Joanna, Zima Aneta, Ślósarczyk Anna

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 1

47--56

EN

Recently, the attention has been drawn to complex systems – biomicroconcretes composed of a bone cement matrix and resorbable granules or microspheres. This paper presents novel bone substitutes composed of α-tricalcium phosphate (α-TCP; cement matrix), calcium sulphate dihydrate granules (GCSD; aggregates in biomicroconcrete) and various polymers (chitosan, sodium alginate, methylcellulose) used for the improvement of material properties. The aim of this work was to study α-TCP-GCSD-polymer interactions and to compare the impact of organic additives on the physicochemical properties of biomicroconcretes. Methods: Scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), X-ray diffractometry (XRD) as well as universal testing machine (INSTRON), Gilmore apparatus and pH/ conduct-meter were used. Results: The chemical bonding between α-TCP matrix and CSD granules resulted in a compressive strength appropriate for low-load bearing applications (7–12 MPa) and clinically relevant setting times (8–33 min). Biomicroconcretes consisting of sodium alginate possessed the highest mechanical strength (12 ± 2 MPa). It has also been found that the dissolution-precipitation reactions of the α-TCP were retarded with the addition of chitosan and acetic acid. This effect was not observed in the case of methylcellulose and sodium alginate. Chemical stability and bioactivity of materials were demonstrated during in vitro studies in simulated body fluid. Conclusions: Materials containing calcium sulphate-based granules were surgically handy, possessed promising physicochemical properties and are supposed to ensure desired macroporosity as well as gradual resorption in vivo. It has been demonstrated that the presence of CSD granules and polymers influenced the physicochemical properties of composites.

3

Transformations of calcium sulphates in solidified carbonated volatile fluidized ashes

Łączny M. J., Bzowski Z.

Journal of Sustainable Mining

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2017

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Vol. 16, iss. 4

151--155

EN

Carbonation of volatile fluidized ashes with the use of carbon dioxide can be a means to their transformation into a product with a possible application as an additive to cement and concrete. Currently, due to its physical-chemical characteristics and particularly because of the high concentration of free calcium oxide, the possible applications of this product are highly limited, perhaps even none existent. A significant reduction or even the complete elimination of CaO can be achieved by its transformation into calcium carbonate. In carbonated volatile fluidized ashes, two components relevant to the binding time of mortar, as well as its durability, can be found: calcium carbonates and calcium sulphates. During the investigation it was assumed that calcium carbonate, being poorly water-soluble, would not react with the remaining components of the porous water of the volatile fluidized ash. Crystalline phases of calcium sulphates, anhydrite, gypsum and bassanite occurring in bound volatile fluidized ashes after carbonation demonstrate the possibility of crystallization in the presence of calcium carbonate. In particular, a change in the concentration of bassanite indicates that this phase, as a precursor to the crystallization of gypsum, may play a significant role in the process of binding carbonated volatile ashes.

4

Equilibrium and kinetic studies of sorption of 2.4-dichlorophenol onto 2 mixtures: bamboo biochar plus calcium sulphate (BC) and hydroxyapatite plus bamboo biochar plus calcium sulphate (HBC), in a fluidized bed circulation column

Alamin A.H., Kaewsichan L.

Polish Journal of Chemical Technology

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2016

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Vol. 18, nr 2

59--67

EN

Sorption studies were carried out to investigate removal of 2.4-dichlorophenol (2.4-DCP) from aqueous solution in a fluidized bed by two types of adsorbent mixtures: BC (Bamboo char plus Calcium sulphate), and HBC (Hydroxyapatite plus Bamboo char plus Calcium sulphate); both manufactured in ball shape. The main material bamboo char was characterized by FTIR, DTA and SEM. The adsorption experiments were conducted in a fluidized bed circulation column. Adsorption, isotherms and kinetic studies were established under 180 min operating process time, at differentinitial 2.4-DCP solution concentrations ranging from 5–10 mg/L, and at different flow rates ranging from 0.25–0.75 L/min. The data obtained fitted well for both the Langmuir and Freundlich isotherm models; indicating favorable condition of monolayer adsorption. The kinetics of both adsorbents complies with the pseudo second-order kinetic model. BC was proven a new effective composite and low cost adsorbent which can be applied in the field of wastewater treatment, and it can also play an important role in industry water treatment.

5

Biodegradable cement type bone implant materials based on calcium phosphates and calcium sulphate

Siek D., Czechowska J., Zima A., Ślósarczyk A.

Engineering of Biomaterials

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2015

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Vol. 18, no. 133

2--6

EN

Calcium phosphates (CaPs) are widely used in hard tissue replacement because of their excellent biocompatibility. Calcium phosphate cements (CPCs) are an interesting alternative for sintered calcium phosphate ceramics due to their mouldability and self-setting properties which allow them to conform to even the most complex bone defects. However, one of the major limitations of CPCs is their relatively low resorption rate, not optimal for bone regeneration. The aim of our studies was to combine a stable hydroxyapatite with more soluble α-tricalcium phosphate (α-TCP) or calcium sulphate (CS) (resorbability: CS>>α-TCP>HA) to develop biomaterial with gradual degradation. Promising materials for use in minimally invasive surgery for bone defects repair were obtained. It was found that the degradation rate of hydroxyapatite based bone substitutes can be controlled by the addition of an appropriate kind and amount of more soluble constituent. The impact of the setting component (α-TCP or CS) on the physicochemical properties of the final products was confirmed. Furthermore the influence of organic additives (chitosan, methylcellulose, alginate) on the final materials characteristic was proven. Solutions of organic additives, applied as the liquid phases, significantly improved the workability of cement pastes. It has been demonstrated that implant materials based on calcium sulphate and α-TCP differed in their setting times, mechanical strength, dissolution rate and morphologies of apatite layers on their surfaces after soaking in simulated body fluid. The reason of observed differences is a higher susceptibility of calcium sulphate to both disintegration and degradation.

6

Electrochemical impedance spectroscopy as a mean of measuring film thickness of calcium sulfate precipitate on an XC70 carbon steel

Lanez T., Chaabia N., Belaid A.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 13, iss. 1

54-61

EN

In this paper we present the use of electrochemical impedance spectroscopy measurement as a tool to measure the thickness of calcium sulphate film formed on an XC70 carbon steel. The solution used is a mixture of sodium sulphate and calcium chloride solution at different concentrations. The film thickness of calcium sulphate is estimated, after an immersion time of 4 days. The results indicate reciprocal relationship between measured capacitance and thickness of calcium sulphate film.

7

Mikrostruktura, skład fazowy i wytrzymałość mechaniczna nowych substytutów kostnych opartych na hydroksyapatycie, fosforanie magnezu i siarczanie(VI) wapnia

Pijocha D., Czechowska J., Bućko M. M., Paszkiewicz Z., Ślósarczyk A.

Materiały Ceramiczne

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2011

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T. 63, nr 4

773-778

PL

Z powodu znakomitej biokompatybilności i bioaktywności fosforany wapnia takie jak hydroksyapatyt (Ca10(PO4)6(OH)2) oraz ß-TCP (Ca3(PO4)2) są z powodzeniem stosowane jako substytuty kostne w ortopedii, chirurgii twarzoczaszki i stomatologii. Jednak, zastosowanie tych materiałów w medycynie ogranicza się do miejsc nie przenoszących znacznych obciążeń ze względu na ich kruchość i niską wytrzymałość mechaniczną. Ich niedostatkiem jest także niezadowalająca poręczność chirurgiczna utrudniająca założenie do ubytków kostnych. Praca dotyczy opracowania i oceny kompozytu złożonego z hydroksyapatytu (HA), cementu magnezowo–fosforanowego (MPC) oraz półwodnego siarczanu(VI) wapnia (CSH) o parametrach optymalnych dla zastosowań medycznych.

EN

Because of excellent biocompatibility and bioactivity, calcium phosphates such as hydroxyapatite (Ca10(PO4)6(OH)2) and ß-TCP (Ca3(PO4)2) are successfully used as bone substitutes in orthopaedics, maxillofacial surgery and dentistry. However, due to low mechanical strength and brittleness, the application of these biomaterials in medicine is limited to places not loaded significantly. Limited surgical handiness is also a disadvantage of calcium phosphates, what makes diffi cult to place the material into bone voids. This study is focused on development of composites containing hydroxyapatite (HA), magnesium–phosphate cement (MPC) and calcium sulphate hemihydrate (CSH), and showing the optimum parameters for medical applications.

8

Preparation methods of calcium sulphate and urea adduct

Malinowski P., Biskupski A., Głowiński J.

Polish Journal of Chemical Technology

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2007

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Vol. 9, nr 4

111-114

EN

The paper presents the results of laboratory studies on the preparation of calcium sulphate and urea adduct by: grinding, compacting and mixing in the presence of physical water. A method for the measurement of urea conversion into the adduct form, which is based on the difference in solubility of free urea and the adduct bound urea CaSO4ź4CO(NH2)2 in n-butanol, was developed. Mixing the reagents in the presence of physical water produced the best results. High urea conversion into the adduct form, over 85%, in the prepared samples indicates that this method can be successfully used to get CaSO4ź4CO(NH2)2 adduct.

9

Dlaczego nie wykorzystuje się odpadów gipsowych w przemyśle gipsowym?

Chłądzyński S.

Izolacje

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2007

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R. 12, nr 3

50-54

PL

W artykule scharakteryzowano alternatywne źródła surowców siarczanowych. Podano ich właściwości, oszacowano aktualne zasoby oraz oceniono perspektywy wykorzystania w przemyśle spoiw i wyrobów gipsowych.

10

Fizykochemiczne podstawy reakcji w układzie [wzór] w odniesieniu do procesów odsiarczania spalin

Kurdowski W.

Chemia i Inżynieria Ekologiczna

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1998

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Vol. 5, nr 10

885-897

PL

Przebiegowi procesu sorpcji [wzór] przez CaO poświęcono wiele prac, lecz pomimo tego mechanizm reakcji nie jest w pełni poznany. Z przeglądu literatury wynika, że jako etap pośredni występuje [wzór], które następnie ulega rozpadowi na [wzór] i CaS. Kinetykę reakcji dobrze opisuje model opierający się na założeniu, że jest ona quasi-pierwszego rzędu w odniesieniu do ciśnienia parcjalnego [wzór] i powierzchni właściwej CaO. Ta powierzchnia właściwa odgrywa decydującą rolę w procesie sorpcji, a nie mniej ważne są porowatość i struktura porów. Ostatnie badania wykazują, że w rzeczywistości równanie kinetyczne jest ułamkowego rzędu w odniesieniu do ciśnienia parcjalnego [wzór].

EN

Although a number of papers have been devoted to the sorption process of [formula] by CaO, the mechanism of this reaction is not yet fully recognized. From a review of the bibliography it appears that as an intermediate stage [formula] occurs, which undergoes subsequently a decomposition into [formula] and CaS. The reaction kinetics is well described by a model based on the assumption that it is quasi first order with regard to the partial pressure of [formula] and specific surface of CaO. This specific surface plays a decisive role in the sorption process, and the porosity and pore structure are not less important. The latest investigations show that in reality the kinetic equation is of fractional order with regard to partial pressure of [formua].