Kaolin | Uses, Benefits, and Safety Precautions | Britannica
Kaolin is used extensively in the ceramic industry, where its high fusion temperature and white burning characteristics makes it particularly suitable for the manufacture of whiteware (china), porcelain, and refractories. The absence of any iron, alkalies, or alkaline earths in the molecular structure of kaolinite confers upon it these desirable ceramic properties.
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Mineralogy and geotechnical properties of alkaline-activated kaolin
KEYWORDS kaolin, alkaline activation, zeolitic tuff, cement kiln dust (CKD), landfill liners, unconfined compressive strength (UCS), hydraulic conductivity 1 Introduction 1.1 Alkali activation Alkali activation of aluminosilicates is a term used to describe the synthesis of alkaliactivated binders at low curing temperatures.
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Thermal and hydrothermal alkaline modification of kaolin for the
Specifically, the study sought to modify Enugu kaolin under thermal and alkaline hydrothermal conditions and study the changes in its physicochemical properties via BET, …
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Coagulation of humic acid and kaolin at alkaline pH
To simulate turbidity a stock Kaolin suspension was prepared using powdered Kaolin (Sigma) having chemical formula Al 2 Si 2 O 5 (OH) 4 [11, 20, 21]. The suspension was stirred for 5 h to allow for complete mixing and dissolution of kaolin in the water and then the solution was left undisturbed for 24 h to allow for the settling of settleable ...
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Separation of alumina and silica from metakaolinite by reduction
Limestone (CaCO 3), which could promote sulfur fixation, was added to coal gangue during roasting in a circulating fluidized bed (CFB) boiler.CaO and CaSO 4 were the main Ca-bearing minerals while metakaolinite was the major Al-bearing mineral in CFB slag. The effect of CaSO 4 and CaO on the separation of alumina and silica from metakaolinite by reduction …
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Chemical Activation of a Kaolinite under Acid and Alkaline Conditions
Activation of the material under acid and alkaline conditions of kaolin has been also studied [55]. Acid treatment, a form of chemical activation, has been used to cause disaggregation of the clay ...
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Preparation and Characterization of Acid and Alkaline Treated Kaolin …
The kaolin clay (KC) samples, which have been subjected to acid and alkali treatments, are designated as KC (HNO 3 ), KC (HCl), KC (H 3 PO 4 ), KC (CH 3 COOH), and KC (NaOH) subsequent to their ...
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Thermal and hydrothermal alkaline modification of kaolin for the
The properties of Enugu kaolin were modified by thermal and alkaline hydrothermal means. The raw and modified kaolin samples were characterized using Brunauer-Emmett-Teller nitrogen adsorption surface area analysis, X-ray fluorescence, X-ray diffraction, Fourier-transform infrared spectroscopy and Scanning electron microscopy techniques.
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Kaolin, fly-ash and ceramic waste based alkali-activated materials
Kaolin, fly-ash and ceramic waste based alkali-activated materials production by the "one-part" method. Author links open overlay panel Adriano Galvão Souza Azevedo a, Kurt Strecker b. Show more. Add to Mendeley. ... The Alkali-Activated Materials (AAM) have emerged in recent decades as a way to minimize the environmental impacts caused by ...
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XRD, FTIR and RAMAN Characterizations of Metakaolin …
(Fluka). The calcination of the kaolin was carried out by heat treatment at a temperature of 750°C for a time of 3 hours: following this calcination, the kaolin (K) was converted into metakaolin (MK). Subsequently, the preparation of the activating alkaline solution was carried out: to do this, sodium trisilicate
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Phase diagram for hydrothermal alkali activation of kaolin and …
Herein, the main motivation of this study is to establish the phase diagram for hydrothermal alkali activation of kaolin and quartz, because these materials are the most abundant and affordable sources of alumina and silica for the low-cost synthesis of zeolites. The effects of the Si/Al ratio, reaction time, reaction temperature, alkali ...
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Study on solids-to-liquid and alkaline activator ratios on kaolin …
Kaolin and alkali activator were mixed with the solids-to-liquid ratios in range of 0.60–1.20 (Al 2 O 3 /Na 2 O molar ratio of 0.63–1.27). Sodium silicate and sodium hydroxide ranged between 0.16 and 0.36 (SiO 2 /Na 2 O molar ratio of 3.19–3.67) were mixed together to prepare alkali activator. The results concluded that compressive strength was affected by both …
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(PDF) Synthesis of kaolin-based alkali-activated cement: carbon
The results showed that the optimal formulation for the alkali-activated kaolin cement developed consists of 62.5 wt.% kaolin, 30 wt.% calcium oxide, 5 wt.% sodium carbonate and 2.5 wt.% sodium ...
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Kaolin
Kaolinite is a mineral belonging to the group of aluminosilicates. It is commonly referred to as "China Clay" because it was first discovered in Kao-Lin, China. The term kaolin is used to describe a group of relatively common clay minerals dominated by kaolinite and derived primarily from the alteration of alkali feldspar and micas.Kaolin is a white, soft, plastic clay mainly …
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Influence of Sintering Temperature of Kaolin, Slag, and Fly Ash
The samples were designed based on three various mix geopolymer designs. Each raw aluminosilicate (kaolin, fly ash, and slag) powder, encompassing NaOH molarity, alkaline activator, solid-to-liquid ratio, and curing temperature were based on previous works and are tabulated in Table 2.The designated mixing design was based on the optimum mechanical …
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New hydrothermal route for the synthesis of high purity nanoparticles
Reducing the activation temperature of kaolin for the synthesis of zeolites and other materials is a not only cost-effective but also green strategy. Hydrothermal alkaline activation (HAA) has been proposed as an effective technique for replacing the traditional high-temperature calcination route.
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Preparation and Characterization of Acid and Alkaline …
Kaolin was refluxed with HNO3, HCl, H3PO4, CH3COOH, and NaOH of 3M concentration at 110 °C for 4 hours followed by calcination at 550 °C for 2 hours. The physico-chemical characteristics of resulted leached kaolinite …
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Kaolins: Their Properties and Uses
The deflocculation of kaolin under alkaline conditions is important, and is assisted by adding a polyanion. The Kubelka-Munk equations have provided a useful basis for interpreting the optical properties of kaolins in terms of an absorption coefficient (k) and a scattering
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Synthesis of kaolin-based alkali-activated cement: carbon …
Kaolin is an aluminosilicate precursor, which is rich in alumina (Al 2 O 3) and silica (SiO 2), it is widely distributed in southern Jordan, which makes them excellent precursors for development of alkali-activated binders, it is also available in commercial quantities and is considered as a main economic resource in Jordan [28].Furthermore, kaolin is abundantly …
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Synthesis of Sodalite Zeolite from Alkaline Fusion of Kaolin …
zeolites from kaolin, there are few examples that employ the alkaline fusion method to destroy the ore's structure. The alkaline fusion method represents an alternative to the hydrothermal treatment method. In this method, the silicoaluminous precursor is fused with potent bases, such as NaOH, at temperatures within the range wherein kaolin
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Acid and alkali treatment of kaolins
Two kaolins containing kaolinites of different crystallinity, as confirmed by the Aparicio-Galán-Ferrell index, were treated in HCl and KOH solutions at 95º and 80ºC, respectively, for periods …
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Preparation and Characterization of Acid and Alkaline Treated Kaolin …
Kaolin was refluxed with HNO3, HCl, H3PO4, CH3COOH, and NaOH of 3 M concentration at 110 °C for 4 hours followed by calcination at 550 °C for 2 hours. The physico-chemical characteristics of resulted leached clay were studied by X-Ray Fluorescence ... Preparation and Characterization of Acid and Alkaline Treated Kaolin Clay.
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Application of meta-kaolin based geopolymer for the removal of
Joseph Davidovits popularized geopolymers [33] which are produced through a reaction between an aluminosilicate precursor and an alkaline activator. A diverse array of inorganic precursors may be utilized, including kaolin [34], meta-kaolin [35], fly ash [36] and so on could be put to work. For alkali activation, we often utilize only two alkaline elements: sodium …
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Kaolin | OIV
The product of the alkaline liquefaction of kaolin taken up by water exhibits the reaction properties of alkaline aluminates and alkaline silicates. 4. TESTS 4.1. Consistency Mix 1 g of kaolin with 1ml of water. The resulting paste should not be runny. 4.2. Water Loss at 700 °C
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(PDF) Kaolin's Physicochemical and Radiological Properties
Kaolin and alkali activator were mixed with the solids-to-liquid ratios in range of 0.60–1.20 (Al2O3/Na2O molar ratio of 0.63–1.27). Sodium silicate and sodium hydroxide ranged between 0.16 and 0.36 (SiO2/Na2O molar ratio of 3.19–3.67) were mixed together to prepare alkali activator. The results concluded that compressive strength was ...
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Chemical activation of a kaolinite under acid and alkaline …
Four metakaolins were prepared by calcination of a natural Spanish kaolin (Navalacruz deposit, Zamora province) at 600, 700, 800, and 900 °C. These four metakaolins, more reactive than the parent kaolin, were submitted to acid and alkaline activations. Acid activation was carried out with 6 M HCl at room temperature and at 90 °C under reflux …
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(PDF) Geopolymer Strength via Solid-Liquid Ratios
Kaolin geopolymers were produced by the alkali-activation of kaolin with an activator solution (a mixture of NaOH and sodium silicate solutions). The NaOH solution was prepared at a concentration of 6-14 mol/L and was mixed with the sodium silicate solution at a Na2SiO3/NaOH mass ratio of 0.24 to prepare an activator solution.
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Kaolins: their properties and uses | Philosophical Transactions of …
The deflocculation of kaolin under alkaline conditions is important, and is assisted by adding a polyanion. The Kubelka-Munk equations have provided a useful basis for interpreting the …
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Synthesis of Sodalite Zeolite from Alkaline Fusion of Kaolin and
In this study, a sodalite-type zeolite (SOD) was synthesized through the alkaline fusion of kaolin and crystallized under ambient pressure conditions, without the need for autoclaves and high temperatures. The influence of the ratio between fused kaolin and water (g/mL) during crystallization was evaluated. The ratio of fused kaolin with NaOH to water at …
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Preparation and Characterization of Acids and Alkali Treated Kaolin …
kaolin and acid, alkaline treated kaolin is shown in . table 4. Lower a cidity of KNaOH can be explained . due to the neutralization of acid sites formed due . to leaching by the strong alkali NaOH.
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