Showing papers on "Aluminium hydroxide published in 2014"
TL;DR: The hydrothermal stability of aluminium hydroxide isophthalate MOF CAU-10-H was proven, under humid multi-cycling conditions and it exemplified the robustness of breathing-like MOFs over 700 water vapour ad/desorption cycles.
Abstract: The hydrothermal stability of aluminium hydroxide isophthalate MOF CAU-10-H was proven, under humid multi-cycling conditions. Detailed in situ thermogravimetric measurements and in situ powder X-ray diffraction analysis during water ad-/desorption were used. A reversible structural change during adsorption was detected and thereby exemplified the robustness of breathing-like MOFs over 700 water vapour ad/desorption cycles. In combination with high water adsorption capacity, hydrophilic CAU-10-H is the first breathing-like MOF with a structural change which is a promising candidate for the use in heat transformation processes.
146 citations
TL;DR: In this article, the applicability of electrocoagulation using aluminium electrodes for the removal of contaminants which can scale and foul reverse osmosis membranes from a coal seam (CS) water sample, predominantly comprising sodium chloride, and sodium bicarbonate, was explored.
Abstract: This work explored the applicability of electrocoagulation (EC) using aluminium electrodes for the removal of contaminants which can scale and foul reverse osmosis membranes from a coal seam (CS) water sample, predominantly comprising sodium chloride, and sodium bicarbonate. In general, the removal efficiency of species responsible for scaling and fouling was enhanced by increasing the applied current density/voltage and contact times (30–60 s) in the EC chamber. High removal efficiencies of species potentially responsible for scale formation in reverse osmosis units such as calcium (100%), magnesium (87.9%), strontium (99.3%), barium (100%) and silicates (98.3%) were achieved. Boron was more difficult to eliminate (13.3%) and this was postulated to be due to the elevated solution pH. Similarly, fluoride removal from solution (44%) was also inhibited by the presence of hydroxide ions in the pH range 9–10. Analysis of produced flocs suggested the dominant presence of relatively amorphous boehmite (AlOOH), albeit the formation of Al(OH)3 was not ruled out as the drying process employed may have converted aluminium hydroxide to aluminium oxyhydroxide species. Evidence for adsorption of contaminants on floc surface sites was determined from FTIR studies. The quantity of aluminium released during the electrocoagulation process was higher than the Faradaic amount which suggested that the high salt concentrations in the coal seam water had chemically reacted with the aluminium electrodes.
56 citations
TL;DR: AOMO is a highly promising adsorbent for the removal of excess fluoride from drinking water and shows an increasing trend with an increase in initial fluoride concentration of the water.
Abstract: In this study, aluminium oxide–manganese oxide (AOMO) composite material was synthesized, characterized, and tested for fluoride removal in batch experiments. AOMO was prepared from manganese(II) chloride and aluminium hydroxide. The surface area of AOMO was found to be 30.7 m2/g and its specific density was determined as 2.78 g/cm3. Detailed investigation of the adsorbent by inductively coupled plasma-optical emission spectrometry, inductively coupled plasma-mass spectrometry, and ion chromatography (for sulphate only) showed that it is composed of Al, Mn, SO4, and Na as major components and Fe, Si, Ca, and Mg as minor components. Thermogravimetric analysis was used to study the thermal behaviour of AOMO. X-ray diffraction analysis showed that the adsorbent is poorly crystalline. The point of zero charge was determined as 9.54. Batch experiments (by varying the proportion of MnO, adsorbent dose, contact time, initial F− concentration, and raw water pH) showed that fluoride removal efficiency of AOMO vari...
44 citations
Patent•
10 Dec 2014
TL;DR: In this article, a heating-free non-alkali liquid accelerator for jetting concrete and a preparation method of the heating free liquid accelerator was described. But the accelerator does not need to be heated in the use procedure.
Abstract: The invention discloses a heating-free non-alkali liquid accelerator for jetting concrete and a preparation method of the heating-free non-alkali liquid accelerator. The liquid accelerator is prepared from the following components in percentage by mass: 30%-55% of aluminum sulfate, 3%-10% of aluminium hydroxide, 10%-18% of hydrofluoric acid, 8%-25% of magnesium salt, 1%-8% of alkylol amine, 0.5%-4% of a stabilizer, and 10%-33% of water. The preparation method is characterized by comprising the following processing steps: putting aluminium hydroxide into a reaction kettle; adding water to the reaction kettle, and stirring aluminium hydroxide into paste; slowly adding hydrofluoric acid, and when the temperature reaches 50-55 DEG C, adding aluminum sulfate to stir in batches; after hydrofluoric acid is completely added, adding residual aluminum sulfate and supplementing residual water, so as to obtain reaction liquid; adding the magnesium salt to the reaction liquid, and then adding the alkylol amine and the stabilizer, so that the solution becomes evenly mixed liquid. The accelerator disclosed by the invention has strong adaptability with cement, low energy consumption and good performance, and does not need to be heated in the use procedure.
23 citations
TL;DR: In this paper, an aluminum hydroxide [Al(OH)3] film on wood substrate has been synthesized by means of the hydrothermal (HT) method for improvement of wood's mechanical properties and resistance to combustion.
Abstract: Abstract Aluminum hydroxide [Al(OH)3] film on wood substrate has been synthesized by means of the hydrothermal (HT) method for improvement of wood’s mechanical properties and resistance to combustion. The HT temperature was set to 100°C and 120°C, and the reaction time varied from 4 h to 10 h. X-ray diffraction (XRD) and X-ray photoelectron spectrometry (XPS) results show that the thin film grown on wood surface was amorphous Al(OH)3 and the relative crystallinity of treated woods slightly improved. SEM observation revealed that the Al(OH)3 film is composed of regular micro/nano-sized spheres, whose production and size increase with the reaction time, and some AlO(OH) structures emerged at 120°C with reaction times longer than 6 h. The storage modulus of the wood treated at 100°C and 120°C for 8 h can be improved by 30%, while the viscoelastic properties are also influenced by the HT treatment and Al(OH)3 coating. The limiting oxygen index of raw wood rose from 24.7% to 27.9% after the treatment, which can be interpreted as a moderate improvement of the fire resistance.
23 citations
TL;DR: In this paper, alternative raw materials were used as a source of alumina: refractory bauxite, primary aluminum hydroxide, and reprecipitated aluminum hydride.
Abstract: Porcelains composed of kaolin-quartz-feldspar are called triaxial porcelains. The use of alumina as a substitute for quartz in porcelains has been developed for some time. The results show a significant improvement in their mechanical properties, but alumina has a high cost. The possibility of using alternative materials as a source of alumina with lower cost was investigated. In this work, alternative raw materials were used as a source of alumina: refractory bauxite, primary aluminum hydroxide, reprecipitated aluminum hydroxide. Compositions with commercial alumina and quartz were also formulated to better understand the effects of adding these alternative materials. The raw materials were milled, dried, and characterized by analysis of the particle size distribution, X-ray diffraction, and X-ray fluorescence. The compositions were formulated by replacing the different sources of alumina in the formulation of porcelain. The compositions studied were shaped by pressing and sintered at different temperatures (1150-1400 oC). The results showed that the use of bauxite and aluminum hydroxide as an alternative source of Al2O3 is viable. The impurities contained in refractory bauxite contributed to the lower values of flexural strength found in compositions having refractory bauxite as a source of alumina. The compositions with reprecipitated aluminum hydroxide showed a high mechanical resistance at low sintering temperatures, while compositions with aluminum hydroxide obtained by the Bayer process achieved good results of mechanical strength in a wide temperature range.
22 citations
TL;DR: In this article, a series of batch adsorption experiments were carried out to assess parameters that influence the fluoride removal process, such as contact time and adsorbent dose, initial fluoride concentration, and pH.
Abstract: In this study the fluoride removal potential of nanoscale aluminium oxide hydroxide (nano-AlOOH) has been investigated. The material was produced using aluminium nitrate (Al(NO 3 ) 3 . 9H 2 O, 95%), and ammonium bicarbonate (NH 4 HCO 3 , 98%) and its density and mineralogy were investigated. A series of batch adsorption experiments were carried out to assess parameters that influence the adsorption process. The parameters considered were contact time and adsorbent dose, initial fluoride concentration, and pH. Results showed that most of the adsorption took place during the first 30 min; and equilibrium was reached at one hour contact time with an optimum adsorbent dose of 1.6 g L -1 for initial fluorideconcentration of 20 mg L -1 . The removal efficiency of fluorideincreased with increase in adsorbent dosage. The fluoride removal efficiency was increased as the pH of the solution increases from pH 3 to 8, but any further increase in pH led to a decrease in fluoride removal efficiency. Maximum adsorption occurred at around pH 7 with initial fluoride concentration of 20 mg L -1 . The adsorption data were well fitted to the Langmuir isotherm model with a maximum adsorption capacity of 62.5 mg F - g -1 . The kinetic studies showed that the adsorption of fluoride by nano-AlOOH obeys a pseudo-second order rate equation. The intraparticle diffusion was not a rate-controlling step for the adsorption process. Thus, the overall study indicates that nano-AlOOH is an efficient defluoridating material. KEY WORDS : Nanoscale AlOOH, Defluoridation, Fluoride removal efficiency, Adsorption capacity, Adsorption kinetics, Adsorption mechanism Bull. Chem. Soc. Ethiop. 2014 , 28(2), 215-227. DOI: http://dx.doi.org/10.4314/bcse.v28i2.6
20 citations
TL;DR: Rodiansono et al. as mentioned in this paper developed a very simple synthetic procedure for the preparation of Ni-Sn alloy catalysts that were utilised for chemoselective hydrogenation of furfural, producing furfuryl alcohol almost exclusively.
Abstract: A very simple synthetic procedure was developed for the preparation of Ni-Sn alloy catalysts that were utilised for chemoselective hydrogenation of furfural, producing furfuryl alcohol almost exclusively. The mixture of nickel nanoparticles supported on aluminium hydroxide (R-Ni/AlOH) and a solution containing tin was treated under hydrothermal condition, producing the as prepared nickel-tin alloy supported on aluminium hydroxide (Ni-Sn/AlOH). H 2 treatment at range of temperature of 673-873 K for 1.5 h to the as prepared Ni-Sn/AlOH produced nanoporous Ni-Sn alloy catalysts. XRD patterns and SEM images revealed that the formation of Ni-Sn alloy of Ni 3 Sn and Ni 3 Sn 2 phases and the transformation of crystalline gibbsite and bayerite into amorphous alumina were clearly observed after H 2 treatment at 873 K. The formation of the Ni-Sn alloy may have played a key role in the enhancement of the chemoselectivity. © 2014 BCREC UNDIP. All rights reserved Received: 1st September 2013; Revised: 26th November 2013; Accepted: 7th December 2013 [ How to Cite : Rodiansono, R., Hara, T., Ichikuni, N., Shimazu, S. (2014). Development of Nanoporous Ni-Sn Alloy and Application for Chemoselective Hydrogenation of Furfural to Furfuryl Alcohol. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1): 53-59. (doi:10.9767/bcrec.9.1.5529.53-59)] [ Permalink/DOI : http://dx.doi.org/10.9767/bcrec.9.1.5529.53-59]
19 citations
TL;DR: In this paper, a coating method was developed to coat polystyrene well-plates as a surface exposable to bacterial adhesion with these minerals (non-treated poly styrene-12 wellplates which are used for cell cultures).
15 citations
TL;DR: In this article, four new chemical grout reagents were used, namely, sodium silicate, calcium chloride, calcium oxide, and aluminium hydroxide, and the injection of the chemicals through the soil by using an electrokinetic method was successfully performed.
14 citations
Patent•
16 Jul 2014
TL;DR: In this article, a method for preparing alumina by using power plant fly ash is described, characterized by: grinding the fly ash, leaching with concentrated sulfuric acid to obtain an aluminum sulfate solution, precipitating aluminum sulfates by concentrating and cooling, dissolving the aluminum sulphate crystals with hydrochloric acid, then letting an HCl gas in the solution to saturate the solution and precipitate AlCl3-6H2O crystals.
Abstract: The invention discloses a method for preparing alumina by using power plant fly ash, characterized by: grinding the fly ash, leaching with concentrated sulfuric acid to obtain an aluminum sulfate solution, precipitating aluminum sulfate crystals by concentrating and cooling, dissolving the aluminum sulfate crystals with hydrochloric acid, then letting an HCl gas in the solution to saturate the solution to precipitate AlCl3-6H2O crystals, reacting the AlCl3-6H2O crystals with an ammonium hydroxide solution or liquid ammonia or an ammonium bicarbonate solution or an ammonium carbonate solution to obtain an aluminium hydroxide and ammonium chloride solution, calcining aluminium hydroxide to obtain alumina, displacing ammonium chloride by using magnesium oxide to obtain ammonia gas and magnesium chloride, and hydrolyzing magnesium chloride to obtain magnesium oxide and hydrochloric acid for recycling.
Patent•
23 Oct 2014
TL;DR: In this article, a method for producing abrasives is described, comprising the following method steps: i.e., providing a starter mixture (5) which preferably contains aluminium hydroxide and can be converted at least into aluminium oxide by sintering, ii. producing a layer (6) of said starter mixture with a predetermined uniform layer thickness (7), dividing said layer(6) into preferably planar material sections (8, 9, 10), reducing the material sections into small pieces by fracturing, and v.
Abstract: The invention relates to a method (1) for producing abrasives (2, 3, 4), comprising the following method steps: i. providing a starter mixture (5) which preferably contains aluminium hydroxide and can be converted at least into aluminium oxide by sintering, said starter mixture (5) preferably being free-flowing, ii. producing a layer (6) of said starter mixture (5) with a predetermined uniform layer thickness (7), iii. dividing said layer (6) into preferably planar material sections (8, 9, 10), iv. reducing the material sections (8, 9, 10) into small pieces by fracturing, and v. sintering, it being either the layer (6) or the material sections (9), or the material sections that were fractured into small pieces (10), that are sintered.
Patent•
07 May 2014
TL;DR: In this article, an anticorrosion wear-resistance coating, comprising the following components in parts by weight: 12-20 parts polyvinyl acetal modified phenolic resin, 8-9 parts of polyacrylic acid vinyl ester emulsion, 3 -13 parts of lead chromate, 3-12 parts of cellulose hydroxypropyl methyl ether, 6-10 parts of m-xylene, 15-21 parts of nano aluminite powder, 3 7 parts of aluminium hydroxide, 12-17 parts of nanocarboxylic
Abstract: The invention discloses an anticorrosion wear-resistance coating, comprising the following components in parts by weight: 12-20 parts of polyvinyl acetal modified phenolic resin, 8-9 parts of polyacrylic acid vinyl ester emulsion, 3-13 parts of lead chromate, 3-12 parts of cellulose hydroxypropyl methyl ether, 6-10 parts of m-xylene, 15-21 parts of nano aluminite powder, 3-7 parts of aluminium hydroxide, 12-17 parts of nano calcium oxide and 4-8 parts of zinc oxide. The anticorrosion wear-resistance coating has the advantages of good anticorrosion performance, excellent wear resistance, long service life and low cost.
Patent•
02 Jul 2014
Patent•
21 May 2014
TL;DR: In this paper, a method for preparing alumina from low-grade bauxite by acid leaching is described, characterized by: grinding the low grade bauxites, leaching with concentrated sulfuric acid, precipitating aluminum sulfate crystals by concentrating and cooling, dissolving the aluminum sulfates with hydrochloric acid and introducing an HCl gas in the solution to saturate the solution, then precipitating AlCl3.6H2O crystals.
Abstract: The invention discloses a method for preparing alumina from low-grade bauxite by acid leaching, characterized by: grinding the low-grade bauxite, leaching with concentrated sulfuric acid to obtain an aluminum sulfate solution, precipitating aluminum sulfate crystals by concentrating and cooling, dissolving the aluminum sulfate crystals with hydrochloric acid, then introducing an HCl gas in the solution to saturate the solution to precipitate AlCl3.6H2O crystals, reacting the AlCl3.6H2O crystals with an ammonium hydroxide solution or liquid ammonia or an ammonium bicarbonate solution or an ammonium carbonate solution to obtain aluminium hydroxide and an ammonium chloride solution, calcining aluminium hydroxide to obtain alumina, carrying out displacement reaction on ammonium chloride and magnesium oxide to obtain ammonia gas and magnesium chloride, and hydrolyzing magnesium chloride to obtain magnesium oxide and hydrochloric acid for recycling.
TL;DR: In this paper, hollow glass beads (HGBs) and aluminium hydroxide (ATH) were used to form a compact char layer on the surface of the sample, and the results showed that there is an obvious synergistic flame retardant effect between HGBs and ATH in this composite.
Abstract: Flame retardant ethylene vinyl acetate (EVA) composites were prepared based on different contents of hollow glass beads (HGBs) and aluminium hydroxide (ATH) in this paper, and the flame retardant properties were studied using limiting oxygen index, UL-94 test and cone calorimeter test respectively. The results showed that EVA-4 with 1·0 wt-%HGBs has the lowest heat release rate, total heat release and smoke production rate among all samples, and HGBs could promote to form a compact char layer on the surface of the sample. It indicates that there is an obvious synergistic flame retardant effect between HGBs and ATH in this composite.
TL;DR: Comparison in vitro ciprofloxacin solubility and dissolution studies were performed in the reactive media containing aluminium hydroxide, calcium carbonate or zinc sulphate, indicating that small volume dissolution experiments can be useful for biorelevant dissolution tests.
Abstract: Ciprofloxacin bioavailability may be reduced when ciprofloxacin is co-administered with metallic ion containing preparations. In our previous study, physicochemical interaction between ciprofloxacin and ferrous sulphate was successfully simulated in vitro. In the present work, comparative in vitro ciprofloxacin solubility and dissolution studies were performed in the reactive media containing aluminium hydroxide, calcium carbonate or zinc sulphate. Solid phases collected from the dissolution vessel with aluminium hydroxide, calcium carbonate and zinc sulphate were investigated for their properties. The results obtained indicate that different types of adducts may form and retard ciprofloxacin solubility and dissolution. In the case of aluminium, no phase changes were observed. The solid phase generated in the presence of calcium carbonate was identified as hydrated ciprofloxacin base. Similarly to iron, a new complex consistent with Zn(SO4)2(Cl)2(ciprofloxacin)2 × nH2O stoichiometry was generated in the presence of relatively high concentrations of ciprofloxacin hydrochloride and zinc sulphate, indicating that small volume dissolution experiments can be useful for biorelevant dissolution tests.
Patent•
15 Oct 2014
TL;DR: In this article, an aluminium hydroxide flame retardant adhesive and a preparation method for its use in the field of flame-retardant materials is described. And the adhesive is processed in a plastication starting stage by using a two-stage plasticating way.
Abstract: The invention discloses an aluminium hydroxide flame retardant adhesive and a preparation method thereof, and belongs to the field of flame retardant materials. The aluminium hydroxide flame retardant adhesive comprises the following components in parts by mass: 40 parts of a chloroprene rubber adhesive, 60 parts of natural rubber, 2 to 5 parts of an anti-aging agent RD, 7 to 15 parts of phenolic resin 12687, 1 to 6 parts of stearic acid, 4 to 10 parts of magnesium oxide, 10 to 30 parts of argil, 10 to 30 parts of carbon black, 20 to 25 parts of aluminium hydroxide, 8 to 14 parts of paraffin oil, 1 to 3 parts of an accelerant M, 1 to 3 parts of an accelerant DM, and 2 to 4 parts of sulphur. Aluminium hydroxide is processed in a plastication starting stage by using a two-stage plastication way. The aluminium hydroxide flame retardant adhesive provided by the invention has a good flame retardant efficiency, the escape of combustible gases can be prevented by using aluminium hydroxide, the formation of soot is avoided, a better flame retardant and smoke suppression effect is played, the tensile strength is high, the stretch rate is good, the production process is simple, and the manufacturing cost and the manufacturing difficulty are lowered.
TL;DR: In this article, the production of alumina from the solid waste cake produced as a byproduct from some aluminium small factories is described. But this work is not directed to the extraction of Al2O3 from the cake.
Patent•
19 Mar 2014
TL;DR: In this paper, an irradiating crosslinking halogen-free flame-retardant material with a non-foaming pipe wall in heating shrinkage is presented, which achieves the American UL224VW-1 standard, and no halogen is contained.
Abstract: The invention discloses an irradiating crosslinking halogen-free flame-retardant material with a non-foaming pipe wall in heating shrinkage. The irradiating crosslinking halogen-free flame-retardant material comprises the following raw materials in parts by weight: 10-100 parts of ethylene-vinyl acetate copolymer, 0.5-10 parts of organosilicon polymer, 0.1-10 parts of antioxidant, 0.1-50 parts of coated red phosphorus flame retardant, 1-150 parts of aluminium hydroxide and/or magnesium hydrate and/or modified aluminium hydroxide and/or modified magnesium hydrate, 0-50 parts of high molecular weight ammonium polyphosphate (APP) and/or 0-50 parts of phosphate flame retardant and/or 0-50 parts of melamine cyanurate (MCA) and/or 0-50 parts of phosphinates, 0.1-100 parts of carbonate and/or phosphate and/or phosphide and/or calcined clay and/or kaoline and/or clay. The irradiating crosslinking halogen-free flame-retardant material can be applied to a heating shrinkage sleeve and the like, the flame retardant grade achieves the American UL224VW-1 standard, and no halogen is contained.
TL;DR: In this article, Zn-Al layered double hydroxide (LDH) nanocrystals were used as a single precursor to fabricate ZnO/Zn-al LDH nanocomposite based on the dissolution of aluminium hydroxides in NaOH.
Abstract: Hierarchical ZnO Nanostructures Derived from Zn-Al Layered Double Hydroxides and their Photocatalytic Activity
In this work, Zn-Al layered double hydroxide (LDH) nanocrystals were used as a single precursor to fabricate ZnO/Zn-Al LDH nanocomposite based on the dissolution of aluminium hydroxide in NaOH. The newly formed ZnO nanorods vertically align on two sides of thinned LDH nanosheet to form “sandwich-like” nanostructure. The following calcination of these ZnO/Zn-Al LDH nanostructures at moderate temperature provided ZnO-Al2O3 mixed metal oxide nanocomposites. Both of ZnO/Zn-Al LDH and ZnO-Al2O3 samples were investigated as photocatalysts and showed selective activity for the photolysis of different dyes under low-Watt UV irradiation. Such photocatalytic mixed metal hydroxide/oxide nanocomposites should facilitate the decontamination of industrial wastewater and be helpful to environmental remediation.
Patent•
05 Nov 2014
TL;DR: In this paper, the burning of polyethylene in the mixture with aluminium hydroxide, aluminium oxide, cellulose and Irganox 1010 has been examined by cone calorimeter under non-standard sizes of the sample.
Abstract: The burning of polyethylene in the mixture with aluminium hydroxide, aluminium oxide, cellulose and Irganox 1010 has been examined by cone calorimeter under non-standard sizes of the sample. The time to ignition of pure polyethylene decreases with decreasing initial amount of polyethylene powder. The subtraction of the mass of water released from the total mass lost for polyethylene with aluminium hydroxide give the same values of effective heats of combustion as for pure polyethylene up to the load about 50 mass% of aluminium hydroxide. The mean heats of combustion determined from the cone calorimeter software are higher than those determined from the total oxygen consumed and mass lost multiplied by the factor 13.1. The additivity rule was found for effective heat of combustion and total smoke released for polyethylene with cellulose. The free radical scavenger Irganox 1010 does not show a significant effect on the flammability of polyethylene except for the increase of the total smoke released. The equation describing the heat release rate evolution in time has been proposed showing a good fit to the experimental runs.
Patent•
29 Oct 2014
TL;DR: In this paper, a heat stabilizer for PVC is described, which is characterized by dissolving sodium terephthalate and aluminium nitrate (aluminium chloride, aluminium sulfate or aluminium hydroxide) in water, stirring at 20-180 DEG C for reacting for 1-24 h, and then filtering, washing and drying.
Abstract: The invention relates to a heat stabilizer for PVC, and preparation and application thereof. The preparation method is characterized by comprising: respectively dissolving sodium terephthalate and aluminium nitrate (aluminium chloride, aluminium sulfate or aluminium hydroxide) in water, stirring at 20-180 DEG C for reacting for 1-24 h, and then filtering, washing and drying, so as to prepare the aluminium terephthalate finished product and apply the finished product as the PVC heat stabilizer. The product is efficient, non-toxic, environment-friendly, low in cost, good in initial-stage dyeing property, excellent in transparency, weatherability and plasticizing property, and relatively good in compatibility with PVC. The product performances are not influenced by usage amount of additives during processing, processing equipment are not easy to wear, and the heat stabilizer has wide application prospect in PVC industry.
Patent•
10 Sep 2014
TL;DR: In this article, a method for comprehensively using aluminum-containing resource is proposed. But the method is not suitable for high energy consumption, high leaching rate of alumina and iron, high enrichment degree of active ingredients and low production cost.
Abstract: The invention belongs to a resource comprehensive using method, and especially relates to a method for comprehensively using aluminum-containing resource. The method comprises the following steps: 1)heating ammonium sulfate and decomposing to generate ammonium bisulfate and ammonia gas; 2)mixing the aluminium-containing resource and ammonium bisulfate in the step 1), adding water or a washing lotion; 3)cooling a reaction product and performing solid-liquid separation, washing to obtain a solution of aluminium ions and iron ions and an excessive ammonium bisulfate solution and high silicon slag; 4)adding ammoniacal liquor or ammonia gas in the solution of the step 3) to obtain aluminium hydroxide and iron hydroxide sediment and an ammonium sulfate solution, then performing solid-liquid separation, and washing; 5)performing evaporative crystallization on ammonium sulfate solution obtained in the step 4), and separating to obtain an ammonium sulfate solid; and 6)processing the aluminium hydroxide and iron hydroxide solid obtained in the step 4) to obtain metallurgy grade alumina and high iron slag. The method has the advantages of low energy consumption, high leaching rate of alumina and iron, high enrichment degree of active ingredients and low production cost.
Patent•
11 Jun 2014
TL;DR: In this paper, a flocculating agent is used to reduce chroma and suspension of wastewater at a well site gas field, which is good in decoloring effect and rapid in filtering speed.
Abstract: The invention discloses a preparation method and application of a flocculating agent. The preparation method comprises: (1) dropwise adding ammonium carbonate into an aluminium chloride solution with stirring to prepare an aluminium hydroxide hydrogel, and performing pumping filtration for reservation; (2) processing the aluminium hydroxide hydrogel prepared in the step (1), adding aluminium chloride, heating and reacting under the condition of 150-180 DEG C for 3-5 h; and (3) dissolving acrylamide monomer in an aqueous solution of HAD, placing in a polymerization bottle; vacuumizing and filling with nitrogen, adding a ceric ammonium nitrate solution into the polymerization bottle under the vacuum state, and shaking uniformly; then vacuumizing again and filling with a certain amount of nitrogen, then transferring the sealed polymerization bottle to a constant-temperature oven with a temperature of 40 DEG C, and reacting for 8-10 h; after polymerization is finished, taking out products, preparing into an aqueous solution with the concentration of about 1%, then precipitating with acetone and extracting for 7-10 h, and then performing vacuum drying at 70-80 DEG C, so as to obtain the flocculating agent. The flocculating agent is good in decoloring effect and rapid in filtering speed, and is capable of effectively reducing chroma and suspension of wastewater at well site gas field.
Patent•
26 Mar 2014
TL;DR: In this article, a method for preparing aluminum hydroxide by utilizing high-alumina coal ash was proposed, which consists of the following steps: pretreating coal ash in a deep desilicication way; primarily dissolving, secondarily dissolving; concentrating and crystallizing the dissolution liquid; dissolving hydrated sodium aluminate crystals; performing desilicization on the sodium aluminates coarse liquid; seed precipitating the aluminium hydroxides; and dealkalizing tailings.
Abstract: The invention relates to a method for preparing aluminum hydroxide by utilizing high-alumina coal ash. By adopting the deep desilicication process and the two-step sub-molten salt dissolution process, not only can the secondary enrichment of the silicon component be realized, but also the aluminum component can be adequately dissolved under the low temperature and low pressure, the operation condition is moderate, the silicon and aluminum can be adequately utilized, and the dissolution rate of the aluminum can reach more than 95 percent. The method comprises the following steps: pretreating the high-alumina coal ash in a deep desilicication way; primarily dissolving; secondarily dissolving; concentrating and crystallizing the dissolution liquid; dissolving hydrated sodium aluminate crystals; performing desilicication on the sodium aluminate coarse liquid; seed precipitating the aluminium hydroxide; and dealkalizing tailings. The obtained desilicication liquid can be used for preparing a liquid controlled process silicon-base product such as white carbon black, and the dealkalized tailings obtained in the process can be used for preparing a solid controlled silicon-base building material such as cement. The raw materials used in the method are wide in source, the price is low, the process is simple, the alkali circulation volume is small, the energy consumption and the water consumption are low, the utilization rate of raw materials is high, and the method is applicable to the industrialized popularization.
Patent•
23 Jul 2014
TL;DR: In this paper, a later-addition ore calcification transformation method in an aluminum oxide production process was proposed. And the method can be used for improving the recovery efficiency of the aluminium oxide in bauxite and realizing the zero discharge of solid waste materials in the production process; the flow rate of materials and the energy consumption in a dissolution process can also be reduced by adopting a later calcium addition method.
Abstract: The invention relates to the field of aluminium oxide production, and particularly relates to a later-addition ore calcification transformation method in an aluminum oxide production process. The method comprises the following steps: extracting aluminium oxide from aluminium-containing ores in a sodium aluminate solution by adopting a high-temperature dissolving manner, and adding a calcium-containing material to ore pulp in a cooling process after dissolving so as to ensure that a silicon-containing phase in dissolution slag completely enters calcified slag; carrying out carbonization transformation, aluminium dissolution, aluminium settlement and the like on the calcified slag so as to obtain calcium aluminate which is used as a calcium source in a later-addition ore calcification transformation process, wherein main components of aluminium-dissolved slag are calcium silicate and calcium carbonate, so that the aluminium-dissolved slag can be directly used as the raw material of the cement industry; and carrying out solid-liquid separation, decomposition and the like on a solution generated in a pressurizing dissolution process so as to obtain aluminium hydroxide, and calcining the aluminium hydroxide so as to obtain aluminium oxide. The method can be used for improving the recovery efficiency of the aluminium oxide in bauxite and realizing the zero discharge of solid waste materials in the production process; the flow rate of materials and the energy consumption in a dissolution process can also be reduced by adopting a later calcium addition method; and the method is a high-efficiency environmental-friendly aluminum oxide production method.
TL;DR: Aluminum hydroxide particles were synthesized from sodium aluminate liquor by urea decomposition method at elevated temperatures in presence and absence of seed in this paper, where different parameters such as alumina to caustic (A:C) ratio, temperature, time period of precipitation, urea concentration, etc.
Abstract: Aluminium hydroxide particles were synthesized from sodium aluminate liquor by urea decomposition method at elevated temperatures in presence and absence of seed. Different parameters such as alumina to caustic (A:C) ratio, temperature, time period of precipitation, urea concentration, etc. were studied. Characterisations of the products were also carried out using X-ray diffraction, scanning electron microscopy, TG-DTA, etc. In general, higher precipitation ratios were observed with the addition of urea in sodium aluminate solution. Temperature was found to have a significant role in precipitating aluminium hydroxide with higher yield enhancement ratio compared to that obtained at lower temperatures. Higher precipitation ratios were also obtained with urea at elevated temperatures under available supersaturation. In the presence of urea, the precipitation ratios on yield enhancement front were observed to increase with decrease in A:C ratio. It has been observed that the liquor concentration reached below the equilibrium solubility limit after 30 h of precipitation when 460 mmol/L urea is added. The synthesized aluminium hydroxide particles showed gibbsitic nature and globular morphology, with agglomerates of mostly hexagonal platelets, as revealed through XRD and SEM studies, respectively. Calcination of the product at 1000 °C results in weight loss similar to that observed with gibbsite. Endothermic peaks at 325 °C and 550 °C revealed through DTA study indicated boehmite and chi-alumina transformations, respectively. The possible mechanism of urea decomposition method is also discussed.
TL;DR: In this paper, a combination of analytical techniques was used to quantify elemental relationships of the formed precipitates as well as their surface charge properties with a novel combination of FESEM analyses, showing that the obtained precipitates were clearly affected by the Al:Si ratio in the initial aqueous solution.
Abstract: Interactions of aluminium (1 mM) and silicon (0.1–2 mM) in aqueous solutions were studied at a low ionic strength medium representing fresh water and water treatment process environments, attempting to quantify elemental relationships of the formed precipitates as well as their surface charge properties with a novel combination of analytical techniques. FESEM analyses showed that the Al:Si ratio in the obtained precipitates was clearly affected by the Al:Si ratio in the initial aqueous solution. According to XRD, the precipitates originated from the 1 mM Al and the 1 mM Al + 0.1 mM Si solutions were gibbsite, while for the initial Al:Si ratios equalling to 1:0.5 or higher, only amorphous material was precipitated. Zeta potential decreased as a function of the initial silicon content, and reached negative values at pH 6.2 with the initial concentrations of 1 mM Al + 2 mM Si. In contrast, for the total surface charge, a maximum value was found between pH 4.5 and 5, and it clearly decreased with the amount of silicon present. To conclude, the dissolved silicon had a significant effect on the formation of charged aluminium species. This may have considerable environmental and health effects. A reaction mechanism for the formation of hydroxyaluminosilicates from silicic acid and aluminium hydroxide was proposed.