Dataset of multiple methodology characterization of an illite-kaolinite clay mineral for the purpose of using it as ceramic membrane supports

This article describes the data generated from multiple approach methodology physico-chemical characterization of a clay mineral from the West-Central region of Morocco, Safi province (https://doi.org/10.1016/j.heliyon.2019.e02281) [1]. Data were generated from classical chemical analytical techniques namely; organic matter content, linear firing and shrinkage analysis, weight loss on ignition, porosity and methylene blue stain tests according to the French Association of Normalization (AFNOR) and American Society for Testing and Materials (ASTM). In addition to data generated using instrumental analytical techniques namely; Infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA) and deferential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and elemental energy disperse spectroscopy (EDX).


Data
Successive weight loss on ignition for both clay powder samples (SA) and (CH) at final temperatures of 250 C, 500 C, 700 C, 800 C, 900 C and 1000 C are presented in Table 1. While, data for the weight loss of compacted clay discs at final Temperatures of 500 C, 700 C, 800 C, 850 C, 900 C, 950 C, 1000 C, 1050 C and 1100 C are presented in Table 2. The Shrinkage analysis data for the compacted flat discs (SA) and (CH) at final temperature of 500 C, 700 C, 800 C, 850 C, 900 C, 950 C, 1000 C, 1050 C and 1100 C are presented in Table 3. The data for water porosity of the fabricated clay supports calcined at final temperatures of 500 C, 700 C, 800 C, 900 C and 1000 C are presented in Table 4. The data of chemical resistance is presented as weight loss fraction (Dm/m o ) of SA and CH compacted flat discs calcined to 850 C and treated with HCl at pH ¼ 5 and NaOH at pH ¼ 10.0. The elemental chemical composition of crude and calcined clays SA and CH at 850 C and 950 C are given in Tables   Specifications Table   Subject area 6.1: Chemistry: Analytical Chemistry More specific subject area Surface analysis, phase analysis Type of data Table, figure and image (blue stain test) How data was acquired ARL-8660 X-Ray Fluorescence Spectrometer SETARAM TGA instrument Bruker Platinum ATR tensor II FTIR spectrometer NABER 2804 furnace X-ray diffraction (XRD) using a D-Max Rigaku X-ray diffractometer with a copper anode and a graphite monochromator to select CuK a1 radiation (l ¼ 1.540 Å). Tescan VEGA XM variable pressure SEM equipped with Oxford Instruments X-Max 50 EDX detector, controlled with AZtecEnergy analysis software with a resolution of 125 eV to determine the abundance of elements. Data format Raw, filtered, analyzed Parameters for data collection Two clay samples (SA) and (CH) were crushed to coarse material, then to fine powder followed by sieving using standardized AFNOR sieves in the range 250e500 mm. Clay flat discs (membrane supports) were prepared from 250 to 500 mm granulometry to obtain pellets with a diameter of 25.0 mm and a thickness of 2.0 mm. Supports were calcined to final temperatures ranging from 250 C to 1100 C. These were used to measure shrinkage/dilatation, chemical resistance and water porosity. Clay powder was used to extract the clay fraction, HCl was used to destroy the carbonates and help extract the clay fractions. While ammonia (NH3) was used to promote deflocculating. ASTM and AFNOR methylene blue tests were used to characterize the clay fractions and specific surface area of the clay samples.

Description of data collection
The tow clay samples (SA) and (CH) were characterized by various methods: XRD, SEM-EDX, FTIR, TGA/TDA and later semi-quantitatively found the concentration of the pure clay fractions (illite and kaolinite) using the blue stain test according to AFNOR and ASTM. Data source location Safi/West region/Atlantic coast/Morocco 10 Km from Safi center. Latitude: 32 16 0 60.00 00 N, Longitude: À9 13 0 60.00 00 W.

Data accessibility
The data represented is with this article. Related research article Abdelaziz Elgamouz, Najib Tijani, Ihsan Shehadi, Kamrul Hasan, Mohamad Al-Farooq Kawam, Characterization of the firing behaviour of an illite-kaolinite clay mineral and its potential use as membrane support, Heliyon, 5 (2019) [1].
Value of the data These data are relevant to ceramic membrane support fabrication, especially fabrication of membrane supports from clay minerals. The data would allow other researchers to identify the key parameters that need to be controlled when investigating new clay material. These data gave a detailed and complete set of experiments that could be used in the characterization of widely available depot of clays and provide an insight on how clay fractions could be characterized and how these could affect the quality of the final products. The data reveal new ways in which largely available clay minerals could be used to develop sustainable and cheap clay supports.  Table 4 Water porosity for SA and CH clays compacted flat discs calcined from at final temperatures of 500 C, 700 C, 800 C, 900 C, and 1000 C at rate of 5 C/min.

Shrinkage analysis
In Eq. (2), L 0 is the diameter of the flat disc before firing and L T is the diameter flat disc after calcination to final temperature T.

Water absorption and porosity
In Eq.
(3), m 0 is the initial weight and m f is the finale weight of the flat disc after firing. In Eq. (4) m o is the mass of the flat disc before pH attack and m pH , is its mass after removing the disc from the acidic (HCl, pH ¼ 5.0) or basic (NaOH, pH ¼ 10.0) solutions for 24 hours.

Blue value (AFNOR)
The blue value of the clay following AFNOR procedure was calculated using Eq. (5).
In Eq. (5), V defines the methylene blue volume flowed in mL, 0.01 is the concentration in g/mL of the methylene blue solution, and M is the mass in grams of the dry sample.
In Eq. (6), E stands for the MB number of equivalents per mL of water, V represents the volume of the MB solution in mL (unit of titration was ¼ 1.0 mL), and W represents the weight of the dry clay sample in g.

Loss on ignition
The loss on ignition was carried out on clay powders, for this 3.0 g of crude clays (SA or CH) where introduced into porcelain crucibles and successively heated to final temperatures of 250 C, 500 C, While the loss on ignition on specimen was carried out on flat disc made by compacting 3.0 g of the SA or CH clay powders with the granulometry of 250e500 mm made by ASTM standardized sieves and under a uniaxial pressure 4:6 Â 10 7 Pa. The obtained pellets with diameter of 25.0 mm and thickness of 2.0 mm were calcined to various final temperatures between 250 C and 1100 C following the same heating program described above.

Shrinkage analysis
For shrinkage analysis, the weight before calcination and after calcination to a final temperature of previously compacted flat discs were recorded and calculations were made according to Eq. (2).

Water absorption and porosity
Flat discs compacted and calcined to temperature equal or above 500 C were immersed in degassed boiled distilled water for a period of 24 h, the discs were removed and dried in the open air for a period of 10 min then weighed and water porosity of the specimen were determined using Eq. (3).

Chemical resistance
The resistance of SA and CH compacted flat discs to drastic acidic or basic conditions were tested by measuring the weight loss of the two specimen after immersing them in HCl solution of pH ¼ 5.0 and NaOH solution of pH ¼ 10.0. The weight losses under acidic and based condition were determined using Eq. (4).

Oxides composition of the clay minerals
The elemental chemical analysis of the natural clay was performed by a Tescan VEGA-XM SEM spectrometer equipped with Oxford Instruments X-Max 50 EDX detector. The EDX measurements were acquired from the characteristic peaks of elements present in the clay (Na, K, Mg, Ca, Al, Si, S, Ti and Fe). Elements concentrations were determined after treatment of signals and the main outcome of the analysis is the (K-ratio). The concentration of the i-th element in the sample was calculated using Eq. (5) [4,5].
The oxides concentration was calculated by using the "Elements by difference" in advanced pan EDX software, oxygen concentration was calculated as difference between 100% and the sum of all other elements. Then, percentages of oxides were calculated by combining oxygen with all other elements that can form oxides [6]. Based on previous studies on clay oxides used were: Na 2 O, MgO, Al 2 O3, SiO 2 , SO 3 , Cl 2 O, K 2 O, CaO, TiO 2 and Fe 2 O 3 [7,8]. The compositions of the two clay samples SA and CH in oxides at different temperatures are given in Tables 5e10.

X-ray diffraction
The clay powder was analyzed using XRD, two types of analysis were carried out on the clay samples. First, non-oriented analysis of fine enough powders was carried out in order to ensure the homogeneity of the sample. Second, 2.0 mm deposited clay fraction on a glass slide, which was extracted using the protocol for clay fraction extraction described later and left to dry for 24 hours at room temperature. In both analysis, non-oriented and oriented fraction, data was recorded using Cu Ka radiation (l ¼ 1.540 Å) on a PW1710 Philips Analytical diffractometer controlled by XPERT Quantify software (EA Almelo, The Netherlands) operating at 40 kV and 30 mA, with a copper anode and a graphite monochromator with a normal divergence (1.0 ) and receiving slits of 0.1 mm dimensions. 1300 points were recorded using continuous scans in a 2q range of 5.0 to 80 .

Clay fraction isolation
To separate elements with fraction less than 2 mm oriented preparation were made in 6 different steps; i-Grinding, it must produce a powder which is not too fine to preserve the clay minerals with a diameter of less than 2 mm [9]. ii-Discharge, it is done with distilled water, then the sample is subjected to magnetic stirring. The coarse material deposited at the bottom of the flask is removed by decanting. iii-Decarbonation, this involves the removal of carbonates (CaCO 3 ). This operation is necessary for several reasons [10], i) the carbonates include the clay minerals, and hence interfere with their deflocculating; ii) they dilute the clay fraction; obstruct the orientation of the preparations by their non-lamellar form. Hydrochloric acid diluted to 10% is added dropwise to the clay suspension with magnetic stirring in order to avoid local overconcentration, while allowing a little time between each attack. pH is controlled with pH meter. When the solution becomes red, this indicate that the carbonates have been destroyed, at this stage it is necessary to stop the HCl addition and the agitation, then the suspension was allowed to settle. iv-Washing, its purpose is to free the sample from the excess of the hydrochloric acid, and to allow deflocculating of the clay fraction. If the supernatant becomes clear, it is enough to wash the sample without using the centrifuge, meaning, pour the supernatant, add distilled water, shake, leave it to decant, and so on until a neutral pH is obtained, pH was controlled by litmus paper. Otherwise, the suspensions were centrifuged at 2500 rpm for 5 min. Subsequently, the supernatant is removed, and the precipitate is re-suspended in distilled water. The precipitate is recovered, tested with pH paper, if it is not yet neutral, the centrifugation cycles must be re-instated until the pH is neutral. v-Suspended Sample, the recovered precipitate is placed in a Beaker of 250 ml, to which distilled water is added, manually shaken, and left to decant for 1h 40mn. If, after 10 minutes, the supernatant is clear. This indicates that deflocculating is poorly performed. For this purpose, one to two drops of ammonia (NH 4 OH) are added which reduces the pH to around 7.0 (the color of the pH paper becomes blue), this is an indication that deflocculating is promoted. vi-Extraction of particles smaller than 2mm, the supernatant must be cloudy so that the suspension is perfect. The contents of the upper 2 cm of the supernatant are recovered and placed in a Beaker of 100 mL. Distilled water was added and centrifuged at 3500 rpm for 40 minutes. The precipitate obtained is recovered by means of a spatula, deposited in glass slides, left to dry for 24 hours at room temperature and finally passed to analysis by X-ray diffraction.

Infrared spectroscopy
The FTIR analysis was carried out in the spectral range (400e4000) cm À1 by a Bruker Platinum ATR tensor II spectrometer with a resolution of 4 cm À1 . A fine clay powder, raw or calcined to the required final temperature was kept in the oven at 70 C, then taken in a desiccator to analysis in order to ensure absorbed waters are not present in the clay samples. The sample was squeezed between the swivel pressure tower and the diamond crystal of the ATR unit, then IR beam was stricken into the sample. Data was recorded in the transmittance mode. Only infrared of SA samples were recorded CH show identical spectra with SA, therefore was not shown.

Methylene blue (MB) stain test
Methylene blue stain test according to AFNOR was carried out using the following procedure [11]; 60.0 g of the clay sample was suspended in 500 mL of distilled water and stirred vigorously until homogenization. 5.0 mL of 10.0g/L of methylene blue solution were added to the homogenized solution using a burette. After each addition, spots (stains) were spotted on a Whatman 1441e055 Quantitative Filter Paper Circles, 20 mm, Grade 41, 55mm Diameter using a capillary. The sampling and spotting continued until the wet surface surrounding the deep blue spot is turned into light blue color. This represents the saturation of the clay by methylene blue.