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Showing papers on "Activated alumina published in 2012"


Journal ArticleDOI
01 Mar 2012-Fuel
TL;DR: In this article, different sorbents were prepared by varying the Ni/Cu loadings onto ZSM-5 and activated alumina for the removal of sulfur from commercial diesel fuel containing approximately 325ppmw total sulfur (S).

109 citations


Journal ArticleDOI
TL;DR: In this paper, an iron-aluminum-cerium hydroxide (Fe-Al-Ce), which has high fluoride adsorption capacity, was granulated via extrusion with cross-linked poly (vinyl alcohol) (PVA) as the binder.

83 citations


Journal ArticleDOI
TL;DR: The potential of a natural, high alumina content, bauxite for the removal of fluoride from contaminated water is investigated.
Abstract: Drinking water contamination by fluoride is recognized as a major public health problem in many parts of the world. In fact, although fluoride is an essential trace element for animals and humans, excessive fluoride intake may cause adverse health effects. In this study we investigated the potential of a natural, high alumina content, bauxite for the removal of fluoride from contaminated water. Both batch and continuous experiments were performed. In continuous-flow column experiments, the effects of inlet fluoride concentration (5–50 mg L

63 citations


Journal ArticleDOI
TL;DR: In this paper, activated alumina balls (3-5 mm diameter) were used for amide synthesis from carboxylic acids and amines under neat reaction conditions that produce no toxic by-products and has the advantages of being low-cost, easily available, heterogeneous, reusable and environmentally benign with no troublesome/hazardous disposal of the catalyst.

61 citations


Journal ArticleDOI
TL;DR: In this paper, the authors used hydrogen peroxide plus formic acid as the oxidant, activated carbon as a reaction enhancer, and power ultrasound for phase dispersion of jet and diesel fuels.
Abstract: The oxidative desulfurization (ODS) of jet and diesel fuels was studied using hydrogen peroxide plus formic acid as the oxidant, activated carbon as a reaction enhancer, and power ultrasound for phase dispersion. When the ODS treatment is followed by an activated alumina post-processing step, overall sulfur removal performance was 98% for JP-8 (at pH 1.4), 94% for diesel (at pH 1.5), and >88% for ultralow-sulfur diesel (at pH 1.5). The ODS treatment converts sulfur compounds to sulfones/sulfoxides, and activated alumina removes the oxidized sulfur compounds to yield a low-sulfur fuel. Control tests reveal that removal of any of the four reaction components (ultrasound, carbon, hydrogen peroxide, and formic acid) reduces the ODS removal performance, with hydrogen peroxide being the most crucial. The response of ODS removal performance to initial oxidant concentrations is consistent with performic acid, formed in situ from hydrogen peroxide and formic acid, being the active oxidizing species. Power ultrasou...

54 citations


Journal ArticleDOI
TL;DR: In this article, three composite adsorbents, sulfate-coated zeolite (SCZ), hydrotalcite (SCH), and activated alumina (SCAA), were characterized and employed for the removal of phosphate from aqueous solution using equilibrium and kinetic batch experiments.
Abstract: Three novel composite adsorbents, sulfate-coated zeolite (SCZ), hydrotalcite (SCH), and activated alumina (SCAA), were characterized and employed for the removal of phosphate from aqueous solution using equilibrium and kinetic batch experiments. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction spectrum were used to study the surface characteristics of the coated layer. Equilibrium tests showed that the adsorption of phosphate followed both Langmuir and Freundlich isotherms. The powder-type SCZ was better for phosphate removal (maximum binding energy, β = 111.49 mg g−1) compared to hydrotalcite and activated alumina. The adsorption of phosphate was considered to take place mainly by ion exchange. The kinetic data followed a pseudo-second-order kinetic model. The initial adsorption of phosphate onto the sulfate-coated adsorbents was fast, indicating that the sulfate-coated materials developed in this study can be used as promising adsorbents for the removal of phosphate from wastewater or sewage.

33 citations


Patent
06 Jun 2012
TL;DR: In this paper, the authors provided an activated alumina and activated carbon compounded material and a preparation method thereof, which can be widely applied to various fields such as industry, agriculture, environmental protection, air purification, water treatment and the like.
Abstract: The invention provides an activated alumina and activated carbon compounded material and a preparation method thereof. According to a formula, the material comprises the following raw materials in percentage by mass: 40 to 99 percent of aluminum hydroxide, 1 to 60 percent of activated carbon, and 15 to 35 percent of binder. The material is prepared by uniformly mixing, pelleting, ageing, molding, airing, sintering, rinsing, drying and the like. The invention aims to compound the activated carbon with the activated alumina; on the one hand, the material with a certain shape can be processed, the defects of loose shape, low strength, difficult recovery and the like of the activated carbon are overcome, and the material is easy to recycle; and on the other hand, the adsorption property of the activated alumina material is greatly improved. The method has the advantages of simpleness, practicality, readily available raw materials, low cost and suitability for industrial mass production, and can be widely applied to various fields such as industry, agriculture, environmental protection, air purification, water treatment and the like.

23 citations


Journal ArticleDOI
TL;DR: In this article, a study has been made on regeneration of activated alumina (AA) and its use in treatment of arsenic contaminated groundwater, since this concentration is optimal upon considering the minimal dissolution of activated AA granules.
Abstract: In this work, a study has been made on regeneration of activated alumina (AA) and its use in treatment of arsenic contaminated groundwater. We have used 2% NaOH solution for regeneration, since this concentration is optimal upon considering the minimal dissolution of activated alumina granules. We have also studied the effect of pH on activated alumina and found that pH > 11.5 is required for arsenic desorption. This technique is cost effective (INR 15 or USD 0.34 approximately per family of 4 people per month) and is capable of treating even 10,000 bed volume of contaminated water with regenerated AA. It is effective even when the predominant species of arsenic in the ground water is As(III). The present study, made during 2004–2007, justifies reduction of pollution load and minimizing financial burden in using regenerated AA at community level arsenic removal unit (ARU).

21 citations


Journal ArticleDOI
TL;DR: In this paper, a novel biosorbent was developed by coating chitosan, a naturally and abundantly available biopolymer, on to activated alumina based on oil shale ash via crosslinking.

21 citations


Patent
17 Oct 2012
TL;DR: In this article, an aluminum sulfate solution and a sodium aluminate solution form a glue in a stainless steel neutralization kettle through a continuous co-current flow method; then an aging treatment is performed for a certain time in a Stainless steel aging washing tank; the resulting material is pressed to a plate and frame filter press with a material pressing pump to carry out continuous washing to prepare primary pseudo-boehmite particles with large grains.
Abstract: The invention relates to a preparation process for large pore volume and light bulk density activated alumina, and belongs to the technical field of activated alumina preparation. According to the process, an aluminum sulfate solution and a sodium aluminate solution form a glue in a stainless steel neutralization kettle through a continuous co-current flow method; then an aging treatment is performed for a certain time in a stainless steel aging washing tank; the resulting material is pressed to a plate and frame filter press with a material pressing pump to carry out continuous washing to prepare primary pseudo-boehmite particles with large grains; the removed filter cake is acidified, and proper amounts of a pore expanding agent and a surfactant are added during the acidification process to carry out forming; the formed wet balls are placed in a drying box to carry out drying; and the dried small balls are loaded into a calcination activation furnace to carry out high temperature calcination and pore expanding. The process of the present invention has characteristics of low cost and low equipment corrosion, can performs continuous washing cycle, and has advantages of low wastewater discharging, less pollution, and the like. With the process of the present invention, the production cycle can be reduced, the labor intensity can be reduced, and various performance indicators of the prepared gamma-Al2O3 can meet the international advanced level after pore expanding by water vapor.

20 citations


Patent
01 Aug 2012
TL;DR: In this paper, the combustion of particulates that have accumulated on a catalyst layer proceeds with good efficiency, in both a rapid combustion region and a slow combustion region, by mixing and aggregating Ce-free and Zr-containing composite oxide particles and activated alumina particles.
Abstract: In the present invention, the combustion of particulates that have accumulated on a catalyst layer (7) proceeds with good efficiency, in both a rapid combustion region and a slow combustion region. A material of Rh-doped Ce-containing composite oxide particles supporting Pt and a material of composite particles supporting Pt are both present on the catalyst layer (7) of the exhaust gas flow path walls of a filter (1). The composite particles are formed by mixing and aggregating Ce-free and Zr-containing composite oxide particles and activated alumina particles.

Journal ArticleDOI
TL;DR: Easily available stone dust and alumina were acid activated, mixed in the ratio of 9:1 and studied for fluoride removal capacity as mentioned in this paper. But the results were limited to a single batch.
Abstract: Easily available stone dust and alumina were acid activated, mixed in the ratio of 9:1 and studied for fluoride removal capacity. Batch and continuous studies were performed to test the efficiency of the adsorbents. Batch study revealed that the mixed adsorbents can remove up to 19.30 mg fluoride per gram of mixed adsorbent and is best removed at pH 6.5. Adsorption studies showed that the mechanism of adsorption is physical sorption. Flow rate plays a significant role in removing fluoride. Breakthrough study of a continuous operated unit tested at three different flow rates showed that decreasing efficiency took place at higher flow rate. The regeneration study shows that this adsorbent can be desorbed following a simple base–acid rinsing procedure.

Journal ArticleDOI
22 May 2012-Water SA
TL;DR: It was demonstrated that a 1st world technology could be effectively applied in a rural area with proper training and supervision of the operators and it appears that fouling of the activated alumina should not be a problem.
Abstract: The fluoride concentration of a borehole water supply in a rural area (Madibeng Local Municipality, North West Province, South Africa) varies between 5 and 6 mg/.. This water is therefore not suitable for potable purposes because the high fluoride concentration may cause mottling of tooth enamel in children and fluorosis in adults. Therefore, the fluoride concentration should be reduced to less than 1.5 mg/. to make the water suitable for potable purposes. The activated alumina and reverse osmosis processes are both processes that can be very effectively applied for water defluoridation. The activated alumina process, however, is considered to be a more simple and robust process for water defluoridation, especially in a rural area. Therefore, the activated alumina process was selected for water defluoridation. An activated alumina plant was designed, constructed and commissioned in the rural area. Fluoride in the feed water is removed from 6 to 8 mg/. to less than 1.5 mg/.. No reduction in plant output was experienced over 6 service cycles. Therefore, it appears that fouling of the activated alumina should not be a problem. Plant output varied between 940 and 1 296 m3 to a fluoride breakthrough of approximately 2.0 mg/.. No significant operational problems were experienced during commissioning and the plant is performing satisfactorily. Spent regenerant is disposed of into evaporation ponds. It was demonstrated that a 1st world technology could be effectively applied in a rural area with proper training and supervision of the operators. The capital and operational costs of the 200 m3/d defluoridation plant are estimated at approximately R1.2m. and R0.7/m3 treated water.

Journal Article
TL;DR: The reliability of the newly developed technique has been established by analyzing spiked water samples of high concentrations of fluoride (upto 50 ppm) and levels of fluoride has been brought down to less than 1 ppm.
Abstract: High concentrations of fluoride in drinking water had caused widespread fluorosis. A simple, precise, rapid and reliable technique has been developed for removal of fluoride in drinking water. The innovative technique employs activated alumina for defluoridation of drinking water. Alumina is inert in nature, hence it is safe to use and handle. The innovation in regeneration of alumina makes the technique cost effective. The reliability of the newly developed technique has been established by analyzing spiked water samples of high concentrations of fluoride (upto 50 ppm) and levels of fluoride has been brought down to less than 1 ppm. The method is superior to currently employed techniques and is recommended to the laboratories where a huge volume of water is to be defluoridated.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the removal efficiency of single and multi-wall carbon nanotubes (SWCNs and MWCNs) from water, and its comparison with two types of fine powder and 150 mesh activated alumina.
Abstract: Fluoride is a kind of anions, which makes its way to the water resources through diverse natural and human activities. Moreover, its health effects are so important and can vary based on the amounts of the intakes to the body. The aim of this study was to investigate fluoride removal efficiency of single and multi-wall carbon nanotubes (SWCNs & MWCNs) from water, and its comparison with the removal efficiency of two types of fine powder and 150 mesh activated alumina. Results show that, using SWCNs, the highest removal efficiency was achieved in pH=5 and sorbent concentration of 0.5 g/L. Moreover, with the increasing of pH the removal efficiency decreased. Meanwhile, fluoride removal efficiency increased with the increasing of the sorbent dosage and decreasing of the initial concentration of fluoride. In conclusion, the SWCNs had higher removal efficiency in comparison with the removal efficiency of both types of the activated alumina in optimum conditions.

Journal ArticleDOI
TL;DR: The experimental results revealed that cerium (IV) loaded phosphorylated orange waste indicated excellent fluoride removal efficiency at acidic pH range and while that lanthanum loaded at neutral pH range.
Abstract: Removal of fluoride is investigated onto several metal ions loaded phosphorylated orange juice residue and commercially available alumina. The experimental results revealed that cerium (IV) loaded phosphorylated orange waste indicated excellent fluoride removal efficiency at acidic pH range and while that lanthanum loaded at neutral pH range. Both the metal loaded adsorbents are found superior to the commercially available activated alumina. DOI: http://dx.doi.org/10.3126/jncs.v27i1.6660 J. Nepal Chem. Soc., Vol. 27, 2011 61-66

Patent
23 May 2012
TL;DR: In this article, a high-temperature heat-insulating coating which is prepared from the following raw materials: 20-70 percent of ceramic fibers, 10-55 percent of water glass or a mixture of the silica sol and the water glass according to any proportion.
Abstract: The invention relates to a high-temperature heat-insulating coating which is prepared from the following raw materials: 20-70 percent of ceramic fibers, 10-55 percent of silica sol or water glass or a mixture of the silica sol and the water glass according to any proportion, 5-40 percent of activated alumina powder or aluminum hydroxide powder or a mixture of the activated alumina powder and the aluminum hydroxide powder according to any proportion, 0-50 percent of filler, 1-10 percent of high-viscosity adhesive, 0-3 percent of foaming agent and water (containing the silica sol, the water glass and the water for dispersing the ceramic fibers) 2-5 times the weight of total weight of solid materials. The prepared high-temperature heat-insulating coating has even adhesion, easy construction,flat coating, high temperature resistance after drying and good heat insulation.

Journal Article
TL;DR: In this article, the ability of rice husk silica to adsorb As(III) from water was examined, and the results showed that the adsorption rate of rice hull silica is 1.897 mg/g which is 10.5x higher than that of activated alumina.
Abstract: Arsenic occurs in groundwater in two valence states, as trivalent arsenite [As(III)] and as pentavalent arsenate [As(V)]. As(III) is more toxic and more difficult to remove from water by adsorption on activated alumina. In this study the ability of rice husk silica to adsorb As(III) from water was examined. Silica was prepared by burning rice husk in a muffle furnace at 500°C. Batch adsorption tests showed that extent of As(III) adsorption depends on pH, initial As(III) concentration and the contact time. Equilibrium adsorption was attained within 180 min, with maximum adsorption occurring at a pH value of 7-8 which is in the pH range for groundwater. The adsorption of As(III) by rice husk silica followed pseudo second-order kinetics. Equilibrium adsorption data were well described by the Langmuir and Freundlich isotherm models. According to the Langmuir isotherm, As(III) adsorption capacity of rice husk silica is 1.897 mg/g which is 10.5x higher than that (0.180 mg/g) of activated alumina. Hence, rice husk silica would be an effective substitute for activated alumina in the removal of As(III) from groundwater at wells or in households.

Patent
24 Oct 2012
TL;DR: In this paper, a high temperature-resistant activated alumina material and a preparation method of the alumina is presented, which can be maintained more than 110 m /g for a long time at a temperature of 1000-1100 DEG C.
Abstract: The present invention provides a high temperature-resistant activated alumina material and a preparation method thereof. The alumina material is prepared by the following steps: mixing macroporous pseudo-boehmite, high viscosity pseudo-boehmite and an additive by using water; uniformly stirring at a rotation speed of 100-1000 r/min; adding dilute nitric acid with a concentration of 30% to carry out a reaction until the pH value is 2.0-5.5 and the solution is at the peptization state, and then aging for 3-6 hours at a temperature of 80-100 DEG C while stirring; adding a pore-forming agent at a room temperature, and carrying out uniform stirring, pulping, spraying and drying; and carrying out calcination at a temperature of 900 DEG C to prepare the alumina. The alumina material of the present invention has advantages of convenient mass production, high specific surface, and the like, wherein the specific surface of the alumina material of the present invention can be maintained more than 110 m /g for a long time at a temperature of 1000-1100 DEG C. In addition, the preparation method of the alumina material has characteristics of simple process and low cost.

Journal ArticleDOI
TL;DR: In this article, the bonding and activity of the atoms near the surface were investigated by spectroscopic analysis of desorption of the adsorbed water molecules, a convenient and quantitative method.
Abstract: Functional ceramics were synthesized using ceramic powders activated by mechanochemical processing. The activated powders were dispersed in an alkali-containing solvent to dissolve the metallic ions at the powder surface and effect re-precipitation between the grains. The “non-firing ceramic process” afforded high-strength ceramic solids without the need for calcination. The key step in this technique is surface activation of the ceramic powders through mechanochemical processing. We investigated the bonding and activity of the atoms near the surface by spectroscopic analysis of desorption of the adsorbed water molecules, a convenient and quantitative method. The powder surface contained an increased number of uncoordinated defects after mechanochemical processing, and powders with high compact strength showed high activity and had high surface AlV content. Diffuse reflectance infrared Fourier transform measurements of the desorption of water molecules allowed for easy and rapid determination of differences in the surface activity, which was not possible when using alternative analysis methods.

Patent
Nobuo Tajima1, Yoshihisa Arai1
12 Jul 2012
TL;DR: In this paper, a method for producing an aqueous hydrogen peroxide solution with a cation-exchange resin resin has been proposed, which can effectively remove an impurity, such as silicic acid or a silicate, contained in an annealing solution.
Abstract: An object is to provide a method for producing an aqueous hydrogen peroxide solution, which can effectively remove an impurity, such as silicic acid or a silicate, contained in an aqueous hydrogen peroxide solution. The method of the present invention for producing an aqueous hydrogen peroxide solution has a first step for contacting an aqueous hydrogen peroxide solution with activated alumina which has been cleaned with purified water, and a second step for, after the first step, contacting the resultant aqueous hydrogen peroxide solution with a cation-exchange resin. The cation-exchange resin is preferably a hydrogen ion-type, strongly acid cation-exchange resin having a sulfonic acid group. The aqueous hydrogen peroxide solution being in contact with the activated alumina and the cation-exchange resin preferably has a temperature of 30° C. or lower.

Patent
27 Jun 2012
TL;DR: In this paper, an integral type catalyst with heat storage function and a preparation method and application of the integral type catalysts is presented. But, the preparation method comprises the following steps: firstly, preparing the activated alumina and the catalyst active ingredients into a coating slurry; and then soaking the heat storage layer into the slurry to prepare the integral-type catalyst with the heat-storage function.
Abstract: The invention discloses an integral type catalyst with heat storage function as well as a preparation method and application thereof. The integral type catalyst is loaded with an activated alumina and catalyst active ingredients on the surface of a heat storage layer, and has an integral porous cellular structure; the heat storage layer consists of at least one of SiC and corundum, dichroite and mullite; the catalyst active ingredients mainly comprise CuO, CoO, Ni2O3 and MnO2, and can be added with Pt, Pd or mixture of the both; and the activated alumina accounts for 2 to 20 percent of the mass of the integral type catalyst. The preparation method comprises the following steps: firstly, preparing the activated alumina and the catalyst active ingredients into coating slurry; and then soaking the heat storage layer into the coating slurry to prepare the integral type catalyst with the heat storage function. The catalyst has the thermal efficiency reaching 96 percent, and can realize high-efficiency purification on industrial organic waste gases after integrating with a reverse flow reactor for catalytic combustion of contaminants under non-steady operation conditions.

Chen, Yan-Qing, Wu, Ren-Ping, Ye, Xian-Feng 
01 Jan 2012
TL;DR: In this article, a new type of activated alumina-activated carbon composite material was discussed, and the influence of heat treatment conditions on the structure and property of this material were discussed; the microstructures of the composite material were characterized by XRD,SEM,BET techniques; and its formaldehyde adsorption characteristic was also tested.
Abstract: AlCl3,NH3·H2O,HNO3 and activated carbon were used as raw materials to prepare one new type of activated alumina-activated carbon composite material.The influence of heat treatment conditions on the structure and property of this material was discussed;The microstructures of the composite material were characterized by XRD,SEM,BET techniques;and its formaldehyde adsorption characteristic was also tested.The results showed that the optimal heat treatment temperature of the activated alumina-activated carbon composite material was 450 ℃,iodine adsorption value was 441.40 mg/g,compressive strength was 44 N,specific surface area was 360.07 m2/g,average pore size was 2.91 nm,and pore volume was 0.26 m3/g.According to the BET pore size distribution diagram,the composite material has dual-pore size distribution structure,the micro-pore distributes in the range of 0.6-1.7 nm,and the meso-pore in the range of 3.0-8.0 nm.The formaldehyde adsorption effect of the activated alumina-activated carbon composite material was excellent,much better than that of the pure activated carbon or activated alumina,and its saturated adsorption capacity was 284.19 mg/g.

Patent
29 Nov 2012
TL;DR: In this paper, a method of manufacturing an alumina-based abrasive grain using boehmite powder and activated alumina powder as starting materials is presented. But this method is not suitable for high hardness and high purity.
Abstract: Provided are a method of manufacturing an alumina-based abrasive grain, which includes preparing boehmite powder and activated alumina powder as starting materials, forming a sol by wet-blending and crushing the boehmite powder, the activated alumina powder, a solvent and a deflocculant, heating the sol at a first temperature which is higher than a room temperature and lower than a boiling point of the solvent and stirring the sol so as not to generate a precipitate, forming a gel by heating the sol at a second temperature higher than the first temperature at which a viscosity of the sol is increased and the sol becomes a paste, blending the gel with an organic solvent and performing wet crushing on the resulting mixture, preparing a powder by drying the wet-crushed gel, blending a binder and a solvent with the dried product, which is the powder, and molding the resulting mixture, calcining the molded product, performing dry crushing on the calcined product, and sintering the dry-crushed product to transform activated alumina and boehmite contained therein to an α-Al 2 O 3 crystal phase, and an alumina-based abrasive grain manufactured thereby. As a result, an alumina-based abrasive grain which is highly dense, has a high hardness, and exhibits a high purity may be manufactured using boehmite powder and activated alumina powder.

Journal Article
TL;DR: In this article, the effect of quaternized rice husk on the adsorption of As(III) was examined and the results showed that the extent of adaption was dependent on pH, As (III) concentration, contact time, and rice hull dose.
Abstract: A number of large aquifers in various parts of the world have been identified with contamination by arsenic. Long-term exposure to arsenic in drinking water causes cancer of the skin, lungs, urinary bladder and kidney, as well as skin pigmentation and hyperkeratosis. Arsenic occurs in groundwater in two valence states, as trivalent arsenite [As(III)] and pentavalent arsenate [As(V)]. As(III) is more toxic and more difficult to remove from water by adsorption on activated alumina. In this study, immobilization (adsorption) of As(III) by quaternized rice husk was examined. Batch adsorption test showed that extent of adsorption was dependent on pH, As (III) concentration, contact time and rice husk dose. Maximum adsorption occurred at pH 7-8, and equilibrium adsorption was attained in 2 h. Equilibrium adsorption data were described by the Langmuir and Freundlich isotherm models. According to the Langmuir isotherm, adsorption capacity of quaternized rice husk is 0.775 mg As(III)/g, which is 4.3x higher than that (0.180 mg As(III)/g) of activated alumina. Quaternized rice husk is a potentially useful adsorbent for removing arsenic from groundwater.

Journal ArticleDOI
TL;DR: In this article, a double pore size activated alumina/activated carbon multiphase material was made by using waste aluminum slag and activated carbon as main raw materials, and the microstructures and pore sizes distribution of the new material were characterized by SEM and BET techniques.
Abstract: A new type of double pore size activated alumina/activated carbon multiphase material was made by using waste aluminum slag and activated carbon as main raw materials. The microstructures and pore size distribution of the new material were characterized by SEM and BET techniques. Iodine adsorption value was used to evaluate the adsorption performance of the multiphase materials, and the benzene adsorption capability was also measured. The results show that the specific surface area of the activated alumina/activated carbon multiphase materials is 261.95m2/g, pore volume can reach 0.25m3/g, and the iodine adsorption value is 381.97mg/g. BET pore size distribution shows that micropores and mesopores both exist in the composite material. The micropores range from 0.6 to 1.4nm, and the mesopores range from 3.0 to 7.0nm. The benzene adsorption capability of this new material is excellent, with a saturated adsorption capacity of 241.00 mg/g, much better than pure activated alumina or activated carbon.

Patent
12 Sep 2012
TL;DR: In this article, a utility model was proposed for the preparation of calcined alumina powder for black ceramics, which is suitable for low-temperature sintering and convenient to operate.
Abstract: The utility model provides a preparation method of calcined alumina powder for black ceramics and relates to a preparation method of calcined alumina powder suitable fore preparing bright high alumina black ceramics. The preparation method of the calcined alumina powder is characterized by comprising the following preparation steps: mixing activated alumina with salt solution of black oxide in proportion, drying and adding an additive capable of refining a crystal grain and uniformly mixing, adding mixed power into a crucible and adding into a high-temperature furnace for calcining to obtain black calcined alumina; and grinding the black calcined alumina to obtain the calcined alumina powder for the black ceramics. Through the method, as the activated alumina is uniformly mixed with the salt solution of the black oxide, the reaction area is increased, and the reaction activity is increased. Meanwhile, the additive capable of refining the crystal grain is added and is calcined into black powder at a proper temperature, the alumina and the black oxide form discontinuous solid solution, and the discontinuous solid solution can stably exist in the ceramic sintering process and is uniformly colorated. The preparation method is high in sintering activity, is suitable for low-temperature sintering and is convenient to operate.

Patent
12 Sep 2012
TL;DR: In this article, a low-cost low-volatile catalytic oxide (VOCO)-based catalyst for the preparation of chlorine gas from chlorine hydride by catalytic oxidation is presented.
Abstract: The invention provides a copper oxide catalyst for preparing chlorine gas from chlorine hydride by catalytic oxidation, and a preparation method and application thereof. The catalyst is prepared from the following components in percentage by weight: 1-20% of CuO, 1-15% of K2O and 65-98% of support, wherein the support is rare-earth oxide modified activated alumina. The invention belongs to an environment-friendly low-cost catalyst; and the rare-earth oxide modified activated alumina is used as the support to enhance the activity and stability of the catalyst and prolong the service life of the catalyst. An isometric impregnation method is utilized to directly support copper and potassium chloride onto the rare-earth oxide modified activated alumina support, and roasting is carried out in an air atmosphere to obtain the supported copper oxide catalyst. The preparation method is simple and easy to implement, and has the advantages of high catalyst activity and high stability.

Patent
29 Nov 2012
TL;DR: In this paper, a method of manufacturing an alumina-based abrasive grain using boehmite powder and activated alumina powder as starting materials is presented. But this method is not suitable for high hardness and high purity.
Abstract: Provided are a method of manufacturing an alumina-based abrasive grain, which includes preparing boehmite powder and activated alumina powder as starting materials, forming a sol by wet-blending and crushing the boehmite powder, the activated alumina powder, a solvent and a deflocculant, heating the sol at a first temperature which is higher than a room temperature and lower than a boiling point of the solvent and stirring the sol so as not to generate a precipitate, forming a gel by heating the sol at a second temperature higher than the first temperature at which a viscosity of the sol is increased and the sol becomes a paste, blending the gel with an organic solvent and performing wet crushing on the resulting mixture, preparing a powder by drying the wet-crushed gel, blending a binder and a solvent with the dried product, which is the powder, and molding the resulting mixture, calcining the molded product, performing dry crushing on the calcined product, and sintering the dry-crushed product to transform activated alumina and boehmite contained therein to an α-Al 2 O 3 crystal phase, and an alumina-based abrasive grain manufactured thereby. As a result, an alumina-based abrasive grain which is highly dense, has a high hardness, and exhibits a high purity may be manufactured using boehmite powder and activated alumina powder.

Patent
27 Jun 2012
TL;DR: In this paper, a preparation method for activated alumina with a large pore volume and a high specific surface area was proposed, which is suitable for industrial production of the target product.
Abstract: The invention especially relates to a preparation method for activated alumina with a large pore volume and a high specific surface area, which belongs to the field of preparation of modified alumina The method comprises the following steps: (1) preparing a nitric acid solution with a concentration of 1 to 3 mol/L, slowly adding a sodium aluminate solution into the nitric acid solution and carrying out stirring so as to obtain sol, wherein, reaction temperature is in a range of 20 to 50 DEG C and the pH value of the nitric acid solution is in a range of 6 to 10; (2) adjusting ageing temperature to be 50 to 90 DEG C and controlling ageing time to be 2 to 10 h; (3) carrying out vacuum suction filtration and washing on the aged sol; (4) mixing a product obtained in step (3) with n-butanol and carrying out co-distillation on an obtained mixture according to a solid-liquid volume ratio of 1:3-8 so as to obtain dry precursor; and (5) roasting the precursor so as to obtain a target product According to the invention, the preparation method is simple, n-butanol can be cyclically used, the target product has a high specific surface area, a large bore diameter and a large pore volume, and industrial production of the target product is convenient