Basic Aluminum Chloride Research Articles

Development of the method for obtaining and studying vitriol of the iron sulphate based on iron-containing wastes

Especially in recent years, a ferric sulfate solution has occupied the attention as a useful water treatment agent and, particularly, a ferric sulfate solution and a basic ferric sulfate solution have a quick sedimentation speed for the resulting flocs and show good deodorizing ability as compared with a water treatment agent of an aluminum type such as an aluminum sulfate solution and la basic aluminum chloride solution whereby they have been widely used as a water treatment agent for waste water from paper manufacturing industry, from food industry, from chemical industry, leather industry. The purpose and task of the research is to develop the technology for the production of iron sulfate salts. For this purpose used iron filings and sulfuric and hydrochloric acid acid were used for this purpose. Processes of dissolution of ferric waste in acid are well studied and are shown.

Anodic Dissolution of Copper in the Acidic and Basic Aluminum Chloride 1-Ethyl-3-methylimidazolium Chloride Ionic Liquid

The anodic dissolution of copper was investigated at a copper RDE in the Lewis acidic and basic composition regions of the room-temperature AlCl3-EtMeImCl ionic liquid (IL) to assess the utility of chloroaluminate liquids as solvents for the electrochemical machining and electropolishing of copper. In the Lewis acidic IL (60 mol % AlCl3), the dissolution of Cu0 proceeds under mixed kinetic-mass transport control with an exchange current density of 7.00 mA cm−2 at 306 K and an apparent activation free energy of 19.7 kJ mol−1. A formal potential of 0.843 V was obtained for the Cu+/Cu0 reaction from potentiometric measurements. In the basic IL (< 50 mol % AlCl3), potentiometric measurements showed that the oxidation of Cu0 resulted in the formation of [CuCl2]−. In this case, the formal potential of the [CuCl2]−/Cu0 reaction is −0.412 V. At small positive overpotentials, the reaction exhibited mixed control and was first order in the chloride concentration, indicating that only a single Cl− is involved in the RDS. However, at more positive overpotentials, the reaction transitions to mass transport control, and a well-defined limiting current is observed for the anodization process. This limiting current scales linearly with the free chloride concentration in the IL.

Deterioration of anion-adsorption abilities of layered double hydroxides synthesized in agarose gel

With the goal of improving solid–liquid separability in wastewater treatment, Mg-Al layered double hydroxides (LDH) were synthesized in agarose gel, and the resulting LDH-containing hybrid hydrogels were dried. The anion-adsorption abilities of the dried hydrogels were compared with those of LDH synthesized by means of a conventional constant-pH coprecipitation method at low supersaturation. A surprising result was found: the adsorption abilities of the dried hybrid hydrogels decreased with storage time, whereas the adsorption abilities of the LDH synthesized by the conventional method remained essentially constant. Further investigation revealed that the adsorption abilities of LDH synthesized by rapid mixing of aqueous Mg-Al and aqueous NaOH at high supersaturation (i.e., a method similar to that used to prepare the hybrid hydrogel) also decreased over time. Therefore, only LDH synthesized by coprecipitation at high supersaturation showed deterioration during storage time in anion-adsorption abilities. Observed results that accompanied the deterioration suggest that the decrease was due to the formation of pockets of mutually adjacent Al-occupied cation sites in the metal hydroxide layers of the Mg-Al LDH as a result of rapid mixing of the starting solutions. The presence of mutually adjacent Al-occupied sites is thought to be in instability due to mutual repulsion. This instability may have led to gradual decomposition of hydroxide moieties containing mutually adjacent Al-occupied sites together with interlayer anions of OH– and Cl− to form aluminum hydroxide or basic aluminum chloride, as well as to separation of nearby Mg(OH)2 moieties from LDH structure.

Influence of the concentration of fluorine ions and clayey particles on the efficiency of aluminum coagulants in defluorination of water

The paper has investigated the influence of the initial concentration of fluorine ions (2.0–8.5 mg/dm3) on the efficiency of sulfate (SA), basic sulfate (OSA 2.0) and basic aluminum chloride (5/6 OXA) in defluorination of water. It has been established that replacement of aluminum sulfate by its basic salts makes it possible not only to reduce consumption of the coagulant, but also provides a possibility to clean waters polluted with fluorine ions by 27–35% without additional introduction of alkaline agents. The paper has shown good promises in using OSA 2.0 for defluorination of low turbidity waters (underground sources), while 5/6 OXA—for water with relatively high contents of suspended impurities.

Novel gastroulcer protective micro(hydro)gels of sulfated locust bean gum-aluminium complex for immediate release of diclofenac sodium

In this study, carboxymethyl sulfate derivative (CLBS) of locust bean gum (LBG) was synthesized by varying the strength of sulfating reagent. CLBS was characterized by Fourier transform infrared (FTIR) spectroscopy, elemental analysis, and viscosity measurements. Furthermore, the degree of sulfation and carboxymethylation in CLBS was determined. Novel micro(hydro)gel particles of CLBS were fabricated in basic aluminum chloride solution and different concentration of diclofenac sodium was incorporated into these particles. Differential scanning calorimetry and FTIR analyses did not suggest any drug-polymer interaction. Spherical morphological structures of the particles were evident under scanning electron microscope. Regardless of the formulation variables, a maximum of ~60% drug entrapment efficiency was achieved. For a higher degree of substitution, CLBS particles disintegrated rapidly (~20 min) and released >80% drug in acidic medium (pH1.2 and pH4.0) in 60 min. However, the particles liberated only ~60% drug in phosphate buffer medium (pH6.8) during this period. Following disintegration of the particles, the pH of gastric environment elevated. In stomach histopathology, the ulcers were scored and it was estimated that CLBS afforded ~86% protection to the gastric mucosa from ulceration. Thus, the micro(hydro)gel particles of CLBS-aluminium complex could be useful for immediate analgesic effect of the drug without any significant gastric distress.

ChemInform Abstract: Preparation of Aluminum Nitride Powder from Aluminum Polynuclear Complexes.

AIN powder was synthesized from aluminum polynuclear complexes. Basic aluminum chloride and basic aluminum lactate were used as the aluminum polynuclear complexes. These starting materials and glucose were dissolved in water and mixed homogeneously. AIN powder was obtained by calcining after drying and precalcining at 800°C under nitrogen gas flow. Then excess carbon was removed by firing in air. Nitridation in the system was investigated and compared with that in the alumina–carbon black system. It was found that in our reaction system nitridation began and proceeded at lower calcination temperatures above 1200°C than in the alumina–carbon black system. Using aluminum polynuclear complexes, AIN was synthesized through the nitridation of γ-alumina and produced in a very fine and sharp particle size distribution.

Role of Corrosion Products in the Suppression of Atmospheric Corrosion of Aluminum and its Alloys

Atmospheric corrosion behaviors of aluminum and aluminum alloys were investigated through 18-month field exposure tests. The corrosion rates decreased with exposure time. The corrosion products formed in the first 3 months mainly consisted of basic aluminum chloride, basic aluminum sulfate and aluminum hydroxide. However, phase transformation took place during exposure and the corrosion products were composed of basic aluminum sulfate and aluminum hydroxide after 12-month exposure. The corrosion products played a key role of the suppression of the atmospheric corrosion on aluminum and its alloys. The membrane potential of basic aluminum sulfate in NaCl solutions indicated that this compound had a cation-selectivity. The sulfate-containing corrosion products prevent the penetration of chloride ions to protect the aluminum substrate. This is responsible for the observed decrease in corrosion rates after prolonged exposure to the atmosphere.

Potentiometric determination of the ‘formal’ hydrolysis ratio of aluminium species in aqueous solutions

The ‘formal’ hydrolysis ratio ( h = C(OH −) added/ C(Al) total) of hydrolysed aluminium-ions is an important parameter required for the exhaustive and quantitative speciation–fractionation of aluminium in aqueous solutions. This paper describes a potentiometric method for determination of the formal hydrolysis ratio based on an automated alkaline titration procedure. The method uses the point of precipitation of aluminium hydroxide as a reference ( h = 3.0) in order to calculate the initial formal hydrolysis ratio of hydrolysed aluminium-ion solutions. Several solutions of pure hydrolytic species including aluminium monomers (AlCl 3), Al 13 polynuclear cluster ([Al 13O 4(OH) 24(H 2O) 12] 7+), Al 30 polynuclear cluster ([Al 30O 8(OH) 56(H 2O) 26] 18+) and a suspension of nanoparticulate aluminium hydroxide have been used as ‘reference standards’ to validate the proposed potentiometric method. Other important variables in the potentiometric determination of the hydrolysis ratio have also been optimised including the concentration of aluminium and the type and strength of alkali (Trizma-base, NH 3, NaHCO 3, Na 2CO 3 and KOH). The results of the potentiometric analysis have been cross-verified by quantitative 27Al solution nuclear magnetic resonance ( 27Al NMR) measurements. The ‘formal’ hydrolysis ratio of a commercial basic aluminium chloride has been measured as an example of a practical application of the developed technique.

Thermal Decomposition of Aluminum Chloride Hexahydrate

The decomposition rate of aluminum chloride hexahydrate (AlCl3·6H2O) was measured as weight loss at ambient pressure and elevated temperatures up to 270 °C. Such incomplete thermal decomposition produces a porous and reactive basic aluminum chloride [Al2O3·2HCl·2H2O or Al2(OH)4Cl2·H2O] which dissolves in water to give poly(aluminum chloride) used as an efficient flocculation agent. A slowly rising temperature method and very small sample masses, which minimize heat and mass transfer intrusions, were employed to determine intrinsic reaction rates. A fractional order kinetic equation of Arrhenius type was proposed for the decomposition and tested also against the results amassed by experiment in a constant temperature mode. This correlation allows the estimation of the reaction rate as a function of temperature and the extent of decomposition. It can be readily employed in modeling and simulation of the decomposition process. The contents of aluminum and chlorine in the decomposed solids were also explored ...

Preparation of transparent alumina film and fiber from a composite of aluminum polynuclear complex/methyl cellulose

Transparent alumina film and fiber were prepared from the inorganic/organic polymer composites as a precursor by heating at 600–1000 °C in air. The composites were composed of basic aluminum chloride (BAC) and methyl cellulose (MC). The composite films were prepared by a casting method of aqueous solution of BAC and MC. An alumina film (40 μm thick) was obtained by heating at 1000 °C for 2 h, which exhibited high transmittance of above 85% in the range of 300–1000 nm. The phase of alumina changed from amorphous to γ-form between 800 and 900 °C. Upon heating at 1150 °C, the alumina transformed to α-form, and the appearance of the alumina film changed to opaque. Colored transparent alumina films were found to be prepared easily from the composite by the introduction of transition metal ions such as Au 3+ and Co 2+. Transparent and continuous alumina fiber was also obtained by heating of the composite fibers made by wet solution spinning of aqueous solution of BAC and MC.

Surface properties and aggregation of basic aluminium sulphate hydrolysis products

The action of pre-hydrolysed coagulants such as basic aluminium chloride (BAC) and sulphate (BAS) in water treatment is of considerable practical and fundamental interest. Variables such as working solution concentration, dosage, pH and ionic strength are known to be important. We have investigated the influence of these variables on the ζ-potential and degree of hydration of hydrolysis products of basic aluminium sulphate samples with different basicities. The products were characterised by a timed ferron complexation procedure, giving information on the degree of polymerisation of the BAS samples. Electrokinetic measurements showed that the ζ-potentials of hydrolysis product particles were consistently higher (more positive) for the higher basicity samples. The ζ-potential decreased with increasing concentration of the working solution and with increased dosage. The degree of hydration of the hydrolysis products was investigated using the spin-lattice relaxation time of protons of water molecules bound to their surfaces. This was found to decrease with increasing basicity of BAS, indicating a greater degree of hydration. Since this effect is expected to decrease ζ potential by a displacement of the electrokinetic shear plane, the observed increase in ζ is probably due to the adsorption of highly charged positive hydrolysis products of BAS.

Separation of titanium dioxide photocatalyst in its aqueous suspensions by coagulation with basic aluminium chloride

A coagulation technique was applied to separate titanium dioxide photocatalyst in its aqueous suspensions after the photocatalyzed degradation of organic contaminants. When a basic aluminium chloride was used as a coagulating agent, titanium dioxide was flocculated and sedimented rapidly; the supernatant solution was practically transparent. After the coagulation with basic aluminium chloride, the titanium dioxide separated from the mother liquor could be satisfactorily reused as a photocatalyst by several simple treatments.

Surface properties and aggregation of basic aluminium chloride hydrolysis products

The influence of major variables (working solution concentration, salt dosage, pH, ionic strength of the solution) on the electrokinetic potential, degree of hydration and aggregation of products of hydrolysis of basic aluminium chlorides (BAC) during water purification has been studied. The degree of hydration characterised by the spin-lattice relaxation time of the protons of adsorbed water increases with increasing basicity ([OH]/[Al] ratio) of coagulants, pH value and with decreasing the dose of salts and the concentration of their working solutions; this is reflected in the change of the ζ-potential of particles. It is shown that an increase of water pH and alkalinity, as well as decrease of BAC basicity lead to the formation of primary particles of a larger diameter (3.1–8.7 nm) whose surface area sharply reduces in the first minutes of aggregate formation. The latter is explained by different size-to-density properties (measured by laser diagnostic method) when varying the conditions of their formation. Aggregation of BAC hydrolysis product particles occurs in a discrete way; aggregates of higher orders are formed not from primary particles but from the first-order aggregates. An increase in basicity of BAC specimens leads to formation of more polydisperse and larger aggregates. The role of electrostatic and hydration factors in the mechanism of aggregation of ABC hydrolysis products is discussed.

Formation of Fibrillar Boehmite

Fibrillar boehmite is a synthetic form of alumina where the morphology is in the form of fibrils instead of the normal corpuscular form. It is prepared from basic aluminium chloride. In this study a molar ratio of Cl−/Al2O3 of 1 was used. During the preparation the crystallinity of the product increases with time up to 48 h of crystallization. During the crystallization the basic aluminiumchlorhydrol is converted to fibrils over a plane leaf-like morphology. This leaf-like morphology is curved to a fibrillar structure. The fibrils maintain about half of their surface area after a thermal treatment at 950°C compared with a treatment at 500°C.

Crystal Structure and Formation of the Aluminium Hydroxide Chloride [Al13(OH)24(H2O)24]Cl15 · 13 H2O

A basic aluminium chloride with high chlorine content (basicity 1.85) has been crystallized from a concentrated aqueous solution. Its crystal structure has been determined by X-ray structure analysis. The structure contains tridecameric cations of a novel type consisting only of interconnected AlO6 octahedra. The formation of these polycations is discussed.

Crystal Structure and Formation of the Aluminium Hydroxide Chloride [Al13(OH)24(H2O)24]Cl15 · 13 H2O

A basic aluminium chloride with high chlorine content (basicity 1.85) has been crystallized from a concentrated aqueous solution. Its crystal structure has been determined by X-ray structure analysis. The structure contains tridecameric cations of a novel type consisting only of interconnected AlO6 octahedra. The formation of these polycations is discussed.

Hydroxy-Al pillaring of concentrated suspensions of smectite clays

The addition of solid 5/6 basic aluminum chloride salt (ACH) to a concentrated (50% w/w) acetone suspension of various dioctahedral and trioctahedral smectites, followed by washing with distilled water and centrifugation, leads to the formation of well formed pillared derivatives (PILCs). The samples were characterized by chemical analysis, X-ray diffraction, N 2 adsorption, 29Si and 27Al MAS NMR spectroscopy, and turned out to be highly microporous with micropore volumes in the range 0.10–0.12 cm 3/g, and with highly ordered clay sheets ( d 001 = 1.8 nm). The number and strength of the acid sites were estimated by analysing the product distribution of the 1-butene isomerization reaction. A mechanism of the pillaring process is proposed on the basis of MAS NMR, XRD, and N 2 adsorption data.

Densities, Viscosities, and Conductivities of Mixtures of Selected Organic Cosolvents with the Lewis Basic Aluminum Chloride + 1-Methyl-3-ethylimidazolium Chloride Molten Salt

The densities, kinematic viscosities, and specific conductances of mixtures of the organic cosolvents acetonitrile, benzene, and dichloromethane with the Lewis basic room-temperature chloroaluminate molten salt aluminum chloride + 1-methyl-3-ethylimidazolium chloride (AlCl 3 + MeEtimCl) were determined at 25 °C. Cosolvents were added to melts containing 49.00 and 44.40 mol % (m/o) AlCl 3 . Polynomial equations were fitted to the results as a function of the mass fraction of the cosolvent. The addition of relatively small amounts of these cosolvents causes a significant decrease in viscosity and a large increase in the conductivity of basic melts

Effect of Polynuclear Complex Content on the Synthesis of Aluminum Nitride from Aluminum Polynuclear Complex

Aluminum nitride powders were synthesized from an aluminum polynuclear complex and glucose. Basic aluminum chloride (BAC) was used as the aluminum polynuclear complex. The effect of the polynuclear complex content on the nitridation reaction and particle size of the AIN powder synthesized was investigated. BAC solutions with various polynuclear complex contents were synthesized using an aqueous solution prepared from AlCl3 and Al metal with various compositions. In this system, AlN was synthesized through γ‐Al2O3 as an intermediate regardless of the polynuclear complex content. Polynuclear complex content affects the reactivity of nitridation and the particle size of the synthesized AIN powder. The reactivity of nitridation and specific surface area of the products increased with the polynuclear complex content. When the precursor with a polynuclear complex content of 94% was calcined at 1400°C, the AlN content reached 95%. Crystallite size by X‐ray diffraction measurement and particle size calculated from the specific surface area for the products were in good agreement, indicating that AlN particles formed in the synthesis process are in the form of single crystals. AlN powder synthesized from the precursor with a polynuclear complex content above 80% had a fine particle size and narrow size distribution.

Kinetics and mechanism of corundum formation in the thermal decomposition of basic aluminium chloride gels

AbstractCompositions and corundum contents in products, formed by thermal decomposition of a basic aluminium chloride gel at temperatures up to 600 °C, were determined at variable temperatures and times of decomposition. For the kinetics of α‐alumina crystallization a model is proposed, valid for diffusion‐controlled two‐dimensional growth. A mechanistic interpretation of these results and of those from previous examinations is based on the essential influence of the gel structure and of the atmosphere in thermal decomposition. As the rate‐controlling step of corundum formation the transportation of HCl and H2O molecules is discussed.