Synthesis of Zeolite 4a for Obtaining Zeolite 5a by Ionic Exchange for Full Utilization of Waste From Paper Industry

Abstract

In order to minimize environmental impact zeolite A was synthesized using waste from the paper industry. This waste is composed of cellulose, kaolin and calcium carbonate. Waste purification was carried through thermal and chemical treatment, which consisted of initial calcination, acid washing with HCl, then calcination of the solid fraction to obtain metakaolin and evaporation of the liquid fraction to obtain CaCl2. Zeolite 4A was produced by static autoclaving under hydrothermal synthesis at different temperatures, crystallization times and NaOH concentrations. As a source of aluminum and silicon metakaolin was used. The synthesis of zeolite 5A was performed by ion exchange with CaCl2. After that, the waste paper (in natura and HCl treatment) and the zeolites 4A and 5A were characterized by XDR, SEM, FTIR, AAS and thermal analysis. The temperature is a key factor in zeolite synthesis at lower concentrations allowing one to obtain zeolite 5A by ion exchange with zeolite 4A.

Towards a Correlation Between Iron/Cobalt Content, Support Pore Size and Metal Particle Size in Supported Catalysts

“…[26] Regarding zeolite 4A, the material has well- defined cubic crystals, which is also reported by several authors. [24,25,35,36] The EDS spectrum shows a Si/Al molar ratio of approximately 0.84, a value close to that reported by Arroyo-Martínez et al, [24] and for LTA zeolite. [37,38]…”

“…[56,57] For zeolite 4A (Figure 10E), bands at 3438 and 1660 cm À 1 refer to stretching and bending of adsorbed water OÀ H bond. [22,25,34] The band at 1451 cm À 1 refers to NÀ H bond bending mode of NH 4 + ions from NH 4 OH. [58,59] The band at 1000 cm À 1 refers to (Si, Al)-O bond asymmetric stretching, while bands at 552 and 460 cm À 1 correspond to vibrations of inner and outer bonds of D4R double rings.…”

Clean Process to Utilize the Potassium-Containing Phosphorous Rock with Simultaneous HCl and KCl Production via the Steam-Mediated Reactions

“…Since the adsorption is the first step prior to the reaction, the total energies of the adsorption between the water molecule and the microcline, silica, and CaCl 2 composites might shed some insightful light on the reaction mechanism. As mineralogy of PS is quite complicated, we only focus on the main mineral composites (shown from PS characterization data in Figure 2 ) such as microcline (the crystal 024 plane was chosen for adsorption using the lattice parameters a = 24.97, b = 9.31, c = 8.57 Å and angles α = 90, β = 81.1, γ = 90), 42 quartz (the crystal −100 plane was chosen for adsorption using the lattice parameters a = 4.913, b = 4.913, c = 5.4052 Å and angles: α = 90, β = 90, γ = 120), 43 and CaCl 2 (the crystal 010 plane was chosen for adsorption using the lattice parameters a = 15.25, b = 18.65, c = 3.64 Å and angles: α = 90, β = 90, γ = 90), 44 respectively.…”

Preparation of magnetic zeolite/chitosan composite using silane as modifier for adsorption of Cr(VI) from aqueous solutions

“…[37] The bands at 956 cm À1 characterize asymmetric stretching vibration of Si-O-Al, which confirms the presence of zeolitic in MZFA. [30] Moreover, the spectrum of the MZFA possesses other three leading absorption bands at 676, 547, and 442 cm À1 , which most likely reflect the symmetric stretching of Si-O-Si, [18] the vibration of thefour-tetrahedra double ring (D4R), and internal vibration of D4R, [18] respectively. Coinciding with the D4R, the Fe─O band of Fe 3 O 4 appeared at 547 cm À1 .…”

“…Figure2illustrates XRD patterns of the materials. The XRD pattern of MZFA exhibits several peaks at 2θ: 7.22 , 10.20 , 12.58 , 16.17 , 20.95 , 24.22 , 27.32 , 30.09 , and 34.15 , which belonged to zeolite were observed [30]. In addition, the peaks of MZFA at 2θ:30.09 , 35.56 , 43.10 , 57.01 , and 62.48 correspond to the characteristic peaks of Fe 3 O…”