Ammonium Alum Research Articles

An H3O-alunite method for production of smelter grade alumina from an ammonium alum solution after high-pressure acid leaching of coal fly ash

Precipitation of H3O-alunite from an ammonium alum solution using boehmite as a seed was studied. The ammonium alum solution was obtained after high-pressure leaching of mullite-type coal fly ash (CFA) with a mixture of 7.5 M H2SO4 + 40% NH4HSO4 at 200 °C. Fe(III) was extracted from the ammonium alum solution by ion exchange sorption using the Purolite S957 resin. Effects of temperature (70–90 °C), seed boehmite (100–400 g/l), ammonium alum (60–240 g/l), and precipitation duration (2–8 h) on the Al precipitation degree were evaluated. Calcination of the precipitate at 300–950 °C to obtain alumina powder was studied next. Concentration of impurities, specific surface area, phase composition, morphology, and the average particle size distribution of alumina powders were investigated. The results show that smelter grade alumina (SGA) can be obtained at optimized parameters of precipitation and calcination.

Enhanced mucoadhesive properties of ionically cross-linked thiolated gellan gum films

Localized oral drug delivery offers several advantages for treating various disease conditions. However, drug retention at the disease site within the oral cavity is indeed a significant challenge due to the dynamic oral environment. The present study aimed to develop a mucoadhesive inner layer for a three-layer mucoadhesive bandage suitable for localized oral drug delivery. using gellan gum (GG) biopolymer. Gellan gum (GG) was modified using L-cysteine moieties via carbodiimide chemistry. Subsequently, gellan gum solution at different extents of thiolation was ionically cross-linked using aluminum ammonium sulfate. Thiolated gellan gum films of uniform thickness were prepared using a solvent casting method. The thickness of bare gellan gum film was 0.035 ± 0.0043 mm, whereas the thiolated gellan gum films, GG 1S and GG 2S showed a thickness of 0.0191 ± 0.0011 mm and 0.0188 ± 0.0004 mm respectively. A high work of adhesion was noted for thiolated gellan gum (GG 2S) with a value of 10 N.mm while using porcine buccal mucosa. An average tensile strength of 48.2 ± 2.46 MPa was measured for thiolated gellan gum films irrespective of the extent of thiolation. The high work of adhesion, favorable cytocompatibility, desirable mechanical properties, and free swell capacity in saline confirmed the suitability of ionically cross-linked thiolated gellan gum films as an inner mucoadhesive layer for the mucoadhesive bandage.

NH4Al(SO4)2·12H2O-Na2SO4 eutectic-based phase change materials with excellent light absorbance, enhanced thermal conductivity, and high latent heat performance

A novel eutectic phase change material with light absorption and high thermal conductivity was successfully prepared. The based phase change material was ammonium aluminum sulfate dodecahydrate‑sodium sulfate eutectic phase change materials. The black Ti2O3 after ball milling was selected as light thermal conversion material which can absorb sunlight effectively and simultaneously convert the light to thermal and the expanded graphite was added to further improve the thermal conductivity of phase change materials. The phase change temperature of the eutectic phase change material was effectively regulated to 80 °C compared with 93 °C of pure aluminum sulfate dodecahydrate. The thermal conductivity of eutectic phase change materials with expanded graphite was enhanced to 1.16 W·m−1·K−1 compared with 0.53 W·m−1·K−1 of the pure eutectic phase change material. By adding Ti2O3, the combination material shows the best solar absorbance capacity of 87.96 % compared with the pure eutectic phase change materials of 73.43 %. The latent heat of the novel material was 190.97 kJ/kg. Considering their huge superiority of highly efficient use of solar energy in natural resources, the new novel ammonium aluminum sulfate dodecahydrate‑sodium sulfate eutectic-based phase change material with excellent light absorbance, enhanced thermal conductivity, and high latent heat performance is a very promising material for solar-thermal conversion and energy storage.

Efficient estimation of crystal filterability using the discrete element method and the Kozeny-Carman equation

A new method is proposed for efficiently predicting filter cake resistance as a function of crystal size distribution. The method is useful for the preliminary design of processes where an economic tradeoff is encountered between a crystallization step and a filtration step. In that case it is necessary to estimate the filter cake resistance repeatedly as a function of crystal size distribution for the process design and optimization. The method is faster than CFD-DEM and more precise than the random packing assumption. The proposed method is validated using published experimental data. To demonstrate the proposed method, an integrated crystallization-filtration process of ammonium alum is simulated and analyzed. The results show that by increasing the residence time of ammonium alum crystals in the crystallizer from 15 min to 60 min, the crystal cake resistance can be reduced by 42% and the filter area can be reduced by 23%.

Reactive Crystallization Kinetics Study of Boehmite in Ammonia Solution by Adding Ammonium Aluminum Sulfate

As an important intermediate product in new techniques for extracting alumina from coal fly ash, boehmite is obtained by the reaction between ammonium aluminum sulfate and ammonia. The reactive crystallization kinetics of boehmite is investigated using a continuous steady-state method. The Mydlarz and Jones (MJ3) models are in considerable agreement with the experimental results by a non-linear regression method; furthermore, crystal nucleation and growth rate equations are proposed. The results revealed that the suspension density and agitation rates present considerable influence on nucleation. Additionally, high levels of supersaturation are not conducive for crystal growth, and the supersaturation index for crystal growth was small due to its poor water solubility. Moreover, the maximum d0.5 (average particle size) was 27.968 μm under the agitation condition and the feed rates of 250 r/s and 0.5 g/10 min. Fast crystal growth speed is associated with the crystal structure’s high AlO6-unit and bulk-oxygen content. Our study on crystal nucleation and growth kinetics will be beneficial to the industrial production of boehmite.

Heat transfer characteristics of PCM slurry using ammonium alum and propylene glycol

For latent heat transportation at temperatures higher than room temperature, a phase change material slurry using ammonium alum, propylene glycol (PG), polyvinyl alcohol (PVA), cationic surfactant, and sodium salicylic acid was proposed. The slurry's phase change characteristics changed with the fraction of PG. In this study, we first confirmed whether PVA and surfactants affected the slurry's phase-change characteristics and viscosity. The results showed that the phase-change characteristics were unaffected, but the viscosity changed to that of a non-Newtonian fluid. Owing to these characteristics, the PVA/surfactant demonstrated a drag-reduction effect in the flow characteristic measurement in a circular pipe flow. However, the drag reduction effects decreased when the PG fraction was large. Using these slurries, heat transfer measurements were performed using a double-tube heat exchanger with an 8-mm inner tube diameter. The samples in the inner tubes were cooled with water. It was observed that the latent heat of ammonium alum enhanced heat transfer and a model of the heat transfer characteristics using the modified Prandtl number was proposed. Finally, the heat transportation efficiency was examined, and it was determined that efficient heat transportation using ammonium alum was feasible under certain PG fraction and flow velocity conditions.

Alumina production: Historical development, issues, and solutions. Part 1

This study focuses on documenting the historical stages of aluminium and alumina production prior to the transition to a modern industry structure, involving the Hall-Héroult electrometallurgical process, and their technical significance for the contemporary metallurgical complex. It highlights the significance of these stages in the development of scientific knowledge related to alumina, aluminium, and their production technology when using chemical methods for obtaining metallic aluminium. The analysis includes aspects, such as classification, technical evaluation of the processes, and the raw material base. It is shown that the formation of scientific knowledge regarding alumina and aluminium is mainly associated with the practical need for using alum and, to some extent, clay minerals. Since the commencement of deliberate research into methods for aluminium production in its elemental state and virtually until the 1890s, aluminium was primarily produced using the metallothermal methods pioneered by Henri St. Clair Deville and his colleagues due to the high thermodynamic stability of aluminium compounds and the absence of affordable energy sources. It was found that from 1854 to 1890, the production of aluminium by chemical method was associated with the use of sodium aluminium chloride (NaCl·AlCl3), natural cryolite, or synthesised fluoride salts. Available technical reagents (aluminium sulphate, ammonia alum, and aluminium hydroxide), along with natural raw materials (cryolite, bauxite, and clay), were used as source materials in this period. The extraction and processing of bauxite were primarily associated with the production of alum and aluminium sulphate consumed by light industry. Although the demand for pure aluminium oxide was limited during the metallothermic production of aluminium, the driving force behind the advancement of modern technologies for alumina production was the demand for chemical products. This demand led to the development of technology for processing bauxite, which forms the foundation of the metallurgical complex in aluminium production using the Hall-Héroult electrometallurgical method.

Factors explaining individual differences in the oral perception of capsaicin, l-menthol, and aluminum ammonium sulfate.

This research focused on the oral perception of naturally occurring chemical food compounds that are used in the pharma and food industries due to their pharmacological properties. They stimulate chemically sensitive receptors of the somatosensory system and are also chemesthetic compounds. Capsaicin is a naturally occurring alkaloid activating pungency perception. l-Menthol is a cyclic monoterpene working also as a medical cooling agent. Aluminum ammonium sulfate is used as a dehydrating agent and additive known to activate astringency in oral cavity. The objective of the study was to identify factors explaining individual differences in the perception of oral chemesthesis measured as sensitivity to chemesthetic compounds and their recognition. The subjects (N = 205) evaluated quality-specific prototypic compounds at five different concentration levels. Differences between gender were discovered in capsaicin sensitivity with men being less sensitive than women. Age was associated with the perception of capsaicin, l-menthol, aluminum ammonium sulfate, and the combined oral chemesthetic sensitivity. Quality-specific recognition ratings were also contributing to the sensitivity to chemesthetic compounds. A combined oral chemesthetic recognition score was created based on quality-specific recognition ratings. Increasing age generally indicated weaker recognition skills. Better recognizers had a higher combined oral chemesthetic sensitivity score than poorer recognizers. These results provide new information about chemesthesis. The results suggest that age and gender are important factors in explaining individual differences in sensitivity to capsaicin, l-menthol, and aluminum ammonium sulfate. In addition, recognition skills are associated with the sensitivity based on the quality-specific recognition scores.

Crystallization kinetics and crystallization process of pseudoboehmite from ammonium aluminum sulfate solution

In this work, the crystallization kinetics of pseudoboehmite was studied by intermittent crystallization method. The kinetic model of pseudoboehmite process was established based on particle number equilibrium. The results show that the nucleation is mainly caused by crystal collision, the main speed control step is diffusion process, and the enlargement of crystals mainly originates from the growth. Reducing the temperature of system can obtain pseudoboehmite crystals which have larger particle size and more uniform particle size distribution. Two parallel octahedral units connected by hydroxyl groups are preferentially stacked along the (020) crystal plane. Excessive interlayer water molecules between (020) crystal planes lead to an increase in the interlayer distance. The increased distance between (020) layers will weaken the hydrogen bond between layers, as well as the electrostatic forces and van der Waals forces, resulting in the formation of folded layers with holes. Finally, the irregularly sheets of pseudoboehmite are stacked to form porous spherical structures.

Preparation of mullite whiskers from high alumina fly ash and its reinforced porous structure

Porous has been formed in samples when mullite whiskers are prepared by firing compacts of high-aluminum fly ash and ammonium aluminum sulfate hydrate with a small amount of sodium dihydrogen phosphate and SiO2 at high temperature for 4 h. The effects of the particle size of fly ash, the firing temperature, and the content of sodium dihydrogen phosphate on the porous structure and the formation of whiskers are discussed. The results show that the smaller the particle size of fly ash, the more uniform porous in sample after fired, which is more conducive to the nucleation of mullite whiskers. Additionally, the amount of whiskers formation increased significantly with the firing temperature increasing, nonetheless, the pore size of porous reduced and the aspect ratio of whiskers gradually increased by reducing the content of sodium dihydrogen phosphate; owing to the reduction of glass melt in the matrix, the Al2O3/SiO2 ratio of the formed mullite whiskers gradually decreased. Thus, in order to obtain mullite whiskers self-reinforcement porous ceramics with the relatively low cost and no pollution to the environment, through the above preparation process, the addition amount of sodium dihydrogen phosphate and calcination temperature should be properly controlled.

Superabsorbent Polymer Sponge for Saliva Absorption Pad

Aim: Saliva is a significant hindrance to most dental procedures (e.g., root canal treatment) as the flow of saliva increases in patients undergoing dental treatment due to anxiety. Saliva absorption pads based on superabsorbent polymers can provide a dry oral environment to ease the dental treatment procedure and reduce the swallowing reflexes common during cotton use. This study focused on developing an indigenous saliva absorption pad using biodegradable superabsorbent polymer (BSAP) sponges. Materials and Methods: BSAP sponges were synthesized using carboxymethyl cellulose (CMC) as the base matrix. Different crosslinking mechanisms were implemented to prepare BSAP sponges, such as ionic crosslinking using aluminum ammonium sulfate (AlAS) and chemical crosslinking using methylene bisacrylamide. Three different BSAP sponges (Sap-2, SAP-PAA-1, and SAP-PAA-2) were characterized for their free swell capacity and thermal degradation kinetics along with other characterization techniques to optimize the composition for saliva absorption pad. One-way ANOVA was used for statistical evaluation. Results: SAP-2, synthesized using 10 wt.% AlAS showed the highest free swell capacity in water and saline (83.21 ± 3.8 g/g and 40.7 ± 3.4 g/g, respectively). However, the moisture content of the particular BSAP sponge was higher (~13%) compared to the standard limit (ISO 17190-4:2001(E)). It was observed that as the crosslinking density increases free swell capacity increases to a threshold point and decreases thereafter. As reported earlier, percentage swelling was controlled by multiple factors including crosslinking that opposes swelling and polymer/water interaction and Donnan pressure that promotes swelling. Conclusion: BSAP sponge based on crosslinked CMC matrix is highly advantageous in developing saliva absorption pad. Hydrophobic surface modification is recommended to reduce the moisture content to improve the storage stability of BSAP sponges.

ПОЛУЧЕНИЕ ЖИДКОГО ТОПЛИВА ИЗ КОРОДРЕВЕСНЫХ ОТХОДОВ ДЛИТЕЛЬНОГО СРОКА ХРАНЕНИЯ МЕТОДОМ ГИДРОТЕРМАЛЬНОГО ОЖИЖЕНИЯ

The pulp and paper industry leads to the formation of a significant amount of bark and wood waste (BWW), which is not processed in Russia, but is placed in bark dumps, which leads to a negative impact on environmental objects, incl. on the planet's climate. This article presents an assessment of the resource potential of long-term storage bark and wood waste based on the results of physicochemical and thermal analysis. It was found that during long-term storage BWW undergoes degradation rather weakly, while the proportion of carbon in the composition of BWW remains practically unchanged (at the level of 48.4%). It has been proven that the initial BWW are characterized by high humidity (60.8% to 74.9%), low calorific value (14.56 MJ/kg per d.m.) and moderate ash content (9.8% d.m.a.). For wet biomass, hydrothermal liquefaction can be considered the most suitable conversion method, which makes it possible to obtain liquid fuels without pre-drying, since. Water in this process acts as a solvent and a source of radicals. The average yield of biofuel during hydrothermal conversion of BWW is 10%, while the use of Iron ammonium alum as catalysts provided an increase in oil yield by more than 2 times to 28.4%, the use of copper sulfate led to an increase in yield up to 16.1%. The obtained bio-oil was characterized by a high degree of saturation (atomic ratio H/C was 1.3), but the oxygen content was also high (at the level of 22% wt.). The content of sulfur and nitrogen was minimal (0.6 and 0.2%, respectively). The composition of fuels was dominated by oxygen-containing aromatic compounds of the phenol group (62%), cyclic esters (19.8%); as well as fatty acids, which account for 12.9%.

A stable new composite phase change material based on H2C2O4⋅2H2O-NH4Al(SO4)2⋅12H2O binary eutectic into ZrO2 modified expanded graphite

As energy shortage intensifies, improving energy efficiency and reducing energy consumption have become essential topics. Herein, a form-stable composite phase change material (FCPCM) consisting of modified expanded graphite (MEG) and eutectic hydrate was designed as a reliable and efficient thermal energy storage medium. Firstly, novel binary eutectic hydrate involving oxalic acid dihydrate (H2C2O4.2H2O) and ammonium aluminum sulfate dodecahydrate (NH4Al(SO4)2.12H2O) served as an excellent thermal energy storage guest. Zirconium dioxide (ZrO2) was used as a hydrophilic modifier because of its high heat resistance, high inertness, corrosion resistance, non-toxicity and countless hydrophilic groups. Therefore, the hydrophilic modified expanded graphite (MEG) as a supporting host was constructed by dip-coating of nano ZrO2 sol on the surface of expanded graphite (EG), which improved its hydrophilicity and compatibility with a eutectic guest. Compared with the original EG (83.05°), the contact angle of MEG containing 10 % ZrO2 on the water was decreased to 37.95°. In addition, the adsorption rate and capacity of MEG to binary eutectic were much faster and larger, reaching an approximate saturation (65.58 %) within 40 min, which was three times that of the untreated EG (23.10 %) in the same adsorption time. The resultant FCPCM containing 24 wt% MEG exhibited a good phase transition temperature (54.10 °C), high phase transition enthalpy (168.5 J/g), as well as excellent anti-leakage behavior. After 100 hot and cold cycles, the thermal performances of FCPCM kept relatively stable, which guaranteed its sustained thermal benefits. It provides a potential application in the field of solar phase change heat exchangers.

Extraction of Al and rare earth elements via high-pressure leaching of boehmite-kaolinite bauxite using NH4HSO4 and H2SO4

High-silica bauxite is not used to obtain sandy-grade alumina owing to its low alumina/silica ratio (μSi < 3). Acidic methods, such as the use of HCl and NH4HSO4, show promise for treating this raw material. The leaching of boehmite-kaolinite bauxite from the Severoonezhsk deposit mine (Arkhangelsk region, Russia) using a mixture of NH4HSO4 and H2SO4 was investigated for the first time. The bisulfate method, which combines the advantages of the acidic and alkaline methods, involves bauxite leaching, precipitation of ammonium alum, recrystallization for gibbsite precipitation, and calcination for alumina production. The effects of temperature (130–200 °C), liquid-to-solid ratio (8–12), and duration of leaching (5–90 min) on the degrees of extraction of Al, and rare earth elements (REEs) were evaluated. The extractions of Al, Fe, and Ga were found to be >90%, with most of the silica and titania remaining in the residue; moreover, a REEs extraction of 70%–80% was achieved. Residues obtained after leaching were studied by laser diffraction, XRD, XRF, and SEM to elucidate the leaching mechanism and the solubility of Al-containing minerals, such as boehmite (AlOOH), kaolinite (Al4[Si4O10](OH)8), and muscovite (KAl2[AlSi3O10](OH)2). The acquired data can be used to facilitate the development of an effective technology for the treatment of high-silica bauxite in Russia.

Features of the Hydrosulfate Method for Processing Alumina-Containing Raw Materials in a Closed Reagent Cycle

The decrease in the availability of high-quality bauxites makes the processing of high-silica raw materials inevitable, and in this regard, it is necessary to develop acid–salt methods suitable for these ores. The purpose of the work was to study various stages of the hydrosulfate method for processing alumina-containing raw materials on the example of nepheline concentrate in order to investigate the possibilities of their improvement. A. The distribution of various macro- and meso-components of leaching between phases at the stage of isolation of ammonium alum depending on sulfate concentration were experimentally and theoretically studied. It was shown that, with an increase in the total concentration of sulfate in the equilibrium mother liquor, the concentration of main impurity components, including iron, in a solid phase decreases significantly. To obtain relatively pure alum, it was recommended to use ammonium hydrosulfate with a concentration of at least 4 mol/L. B. Different embodiments for further purification of alum were explored. It was found that the use of the recrystallization process in the presence of small additions of sodium thiosulfate reduces the content of iron impurities in alum by almost an order of magnitude. C. A method for isolating purer final product was demonstrated. Isolation of ammonium aluminum carbonate hydroxide (ASACH), as a precursor of high-purity alumina, using ammonium bicarbonate is currently the most promising method in the hydrosulfate technology. In combination with the process of recrystallization, the preparation of AACH makes it possible to eliminate the need for expensive methods of selective sorption or extraction for deep purification of aqueous solutions of alum.

Preparation and thermal properties of novel inorganic-organic eutectic composite material with high latent heat and thermal conductivity based on aluminum sulfate salt

Potassium aluminum sulfate dodecahydrate (Alum) and ammonium aluminum sulfate dodecahydrate (AAS) are two potential inorganic phase change materials with high transformation enthalpy. To make them more flexible to match temperature requirements of various fields, the melting temperature needs to be manipulated but less effect on latent heat. In this work, two novel eutectic mixtures of Alum-E and AAS-E were obtained by adding erythritol (E) with high latent heat into aluminum sulfate salts. The results denoted that the melting temperatures of the two eutectic mixtures were 72.46 °C and 73.20 °C when containing 35 wt% and 37 wt% erythritol, respectively. It was worth noting that they still possessed high latent heat of 243.4 J/g and 257.4 J/g. Considering the stability of NH4+ at high temperature, Alum-E was chosen to fabricate Alum-E/EG (expanded graphite) composite material with high thermal conductivity via melt-blending method. EG not only increased the thermal conductivity from 0.61 W/(m·K) to 10.95 W/(m·K) as an excellent enhanced heat transfer carrier, but also prevented leakage of Alum-E/EG composite material effectively as a porous adsorption carrier when contained 15 wt% EG. Moreover, the thermal stability tests indicated that Alum-E possessed favorable thermal stability after 250 heat-cooling cycles. Above all, the obtained composite energy storage material is a promising candidate for afterheat recovery and medium and low-temperature energy storage areas else.

PCM Slurry using Ammonium Alum and Propylene Glycol for Heat Transportation

A phase-change material (PCM) slurry for storing and transporting waste heat was studied. The PCM used in this study was ammonium aluminum sulfate dodecahydrate (ammonium alum). Ammonium alum has a melting point of 93.5°C and a latent heat of 259.9 kJ kg−1; however, ammonium alum slurry (prepared by mixing ammonium alum and water) has a lower latent heat of 12.1 kJ kg−1 (at a mass fraction of AlNH4(SO4)2 of 15 wt%) owing to its high solubility. To decrease the solubility of ammonium alum, novel ammonium alum slurry was proposed using propylene glycol (PG) as a poor solvent. In this study, the solubility of ammonium alum in PG and water mixtures was measured. The phase change characteristics were measured using differential scanning calorimetry (DSC). The effects of the mass fraction of ammonium alum and the mass fraction of PG on the melting point and latent heat of the PCM were investigated. It was observed that when the mass fraction of PG increased, the latent heat and melting point increased. In this case, for the same melting point, the volume of particles of ammonium alum can be reduced by adding PG. The viscosity of the saturated ammonium alum solution was measured using a rheometer. The viscosity of the slurry was estimated using Einstein's viscosity equation. The heat-transfer efficiency of the prepared ammonium slurry was analyzed based on these results. It was concluded that the slurry proposed in this study is effective for heat transportation.

Peer review of the pesticide risk assessment of the active substance aluminium ammonium sulfate.

The conclusions of the EFSA following the peer review of the initial risk assessments carried out by the competent authorities of the rapporteur Member State, Ireland, and co‐rapporteur Member State, Portugal, for the pesticide active substance aluminium ammonium sulfate and the considerations as regards the inclusion of the substance in Annex IV of Regulation (EC) No 396/2005 are reported. The context of the peer review was that required by Commission Implementing Regulation (EU) No 844/2012, as amended by Commission Implementing Regulation (EU) No 2018/1659. The conclusions were reached on the basis of the evaluation of the representative uses of aluminium ammonium sulfate as a repellent on row crops (salad, brassica, carrots and other vegetable crops), combinable crops (grains, pulses and oilseed rape), grassland (primarily amenity and sports turf), orchards and forestry, amenity and ornamentals including use on hard surfaces. The reliable end points, appropriate for use in regulatory risk assessment, are presented. Missing information identified as being required by the regulatory framework and assessments not finalised are listed.

An exploratory study on strategic metal recovery of coal gangue and sustainable utilization potential of recovery residue

Coal gangue is a resource that is often improperly managed, especially during the current strategic metal element shortage. Achieving the efficient and green cooperative recovery of primary elements and strategic metal elements is critical, especially in the treatment without acid and alkali. In this study, the low-temperature combined roasting-DI water leaching method extracted valuable elements and prepared adsorption materials from coal gangue. The element migration and reaction mechanisms were investigated in detail. The results show that the primary reaction path includes the decomposition of ammonium sulfate into ammonium hydrogen sulfate, which reacts with kaolinite to form aluminum ammonium sulfate. Al, Fe, Ga, Li, Mg, Sr, Ti, and V were strongly correlated during roasting. The combined roasting of ammonium chloride and ammonium sulfate promoted the dissolution of Al and Li significantly. The specific surface area of water-leached gangue residue was adjusted by combined roasting, and its adsorption effect on lead ions was stronger than that of raw gangue and kaolinite. The present process presents an eco-friendly solution for the comprehensive utilisation of coal gangue.

Effect of SDBS on Crystallization Behavior of Pseudoboehmite

Coarse-grained pseudoboehmite was obtained by neutralization of an ammonium aluminum sulfate solution [NH4Al(SO4)2·12H2O] with ammonia water [NH3 (aq)] in the presence of sodium dodecylbenzene sulf...