346results about "Hydrotalcite" patented technology

The invention provides a nano-size layered double hydroxide and a step-by-step precipitation preparation method thereof. The preparation method comprises the following steps: based on a soluble salt of a metal and an alkali as raw materials, respectively precipitating metal ions constituting an LDH (layered double hydroxide) layer plate through step-by-step precipitation reaction and generating the LDH during the second-step precipitation process. As the activity of the hydroxide prepared by the first-step precipitation reaction is high, the LDH can fast nucleate and grow during the second-step precipitation, an obtained LDH sheet is thinner, the thickness of the layer plate is 5-15nm, the length of the layer plate is 50-150nm, and the specific surface area of a BET (Brunauer-Emmett-Teller) is 140-280m<2> / g, which is much larger than the specific surface area of the common LDH. By adopting the method, the shortcoming of small specific surface area during the preparation of the LDH through a co-precipitation method can be overcome. The preparation method adopted by the invention is simple and convenient, high temperature and high pressure are not required, special equipment is not required, sources of the raw materials are rich, and the cost is low. The layered double hydroxide can be widely applied to the fields of adsorption separation, catalysis, high polymer materials and the like.

Anionic clay compounds such as hydrotalcite-like compounds can be made by a process wherein a non-hydrotalcite-like compound (or a hydrotalcite-like compound) are heat treated and then hydrated to form hydrotalcite-like compounds having properties (e.g., increased hardness and / or density) that differ from those of hydrotalcite-like compounds made by prior art methods wherein non-hydrotalcite-like compounds (or hydrotalcite-like compounds) are not similarly heat treated and hydrated to form such hydrotalcite-like compounds.

This invention relates to a method for preparing lamellar dihydroxyl composite metal oxide microspheres. The method comprises: preparing lamellar dihydroxyl composite metal oxide (hydrotalcite) nano- or submicro-particles by co-precipitation, nucleation / crystallization / isolation, nonequilibrium crystallization or hydrothermal synthesis, preparing into slurry with a certain solid content, adding bonding agent, spin-spraying for granulation, and drying to obtain microspheres with diameters of 5-100 mu.m. The bulk density, specific surface area, pore volume and most probable pore diameters of the microspheres are 0.4-0.8 g / cm3, 40-150 m2 / g, 0.1-0.8 cm3 / g and 2-40 nm, respectively. The microspheres can be directly used for catalysis or separation after activated, and the mass transfer resistance and carbon accumulation are minimized.

The present invention relates to the field of the hydrotalcite, discloses magnesium aluminum hydrotalcite and a method for preparing the magnesium aluminum hydrotalcite, the method comprises the following steps: (1) in the presence of water, performing ball-milling on a magnesium source and / or aluminum hydroxide to obtain a sol precursor; (2) diluting the sol precursor with water, mixing the diluted solution with the magnesium source and / or aluminum hydroxide, contacting the obtained mixture with an acid matter, and thermally insulating at 30-90 DEG C for 10-300min to obtain a magnesium aluminum composite sol; (3) under hydrothermal reaction conditions, contacting the magnesium aluminum composite sol with a crystal form control agent to obtain magnesium aluminum hydrotalcite paste; and (4) contacting the magnesium aluminum hydrotalcite paste with a surface modification agent for reaction. The method has the advantages of simple process and low cost, and can improve the crystallinity of the magnesium aluminum hydrotalcite.

The present invention discloses a nano magnesium-aluminum hydrotalcite, wherein a soluble magnesium salt, a soluble aluminum salt, a soluble carbonate and an alkaline precipitant are adopted as main raw materials. A foaming assistant is added into the above raw materials. Firstly, a precursor filter cake is prepared through the reaction of a gas bubble liquid membrane. After that, the nano magnesium-aluminum hydrotalcite is prepared based on the hydrothermal reaction through the filtering, washing and drying process. According to the invention, the nano magnesium-aluminum hydrotalcite is prepared based on the combination of the gas bubble liquid membrane process and the hydrothermal reaction. The prepared nano magnesium-aluminum hydrotalcite is uniform in particle size, high in purity, good in dispersibility and good in repeatability. Meanwhile, the preparation process is simple and environment-friendly, and the large-scale production of the nano magnesium-aluminum hydrotalcite is realized. The reaction of the gas bubble liquid membrane can be conducted at a normal temperature and the energy consumption is reduced. The production cost is saved.

The invention discloses an intercalated layered double hydroxide smoke inhibitor and a preparation method thereof. The smoke inhibitor is a layered structural material formed by assembling a laminated sheet consisting of metal cations and interlayer anions, wherein a specific composition general formula of the smoke inhibitor is M<2+>1-xM<3+>x(OH)2(A<n->)n / 2.mH2O. According to the preparation method disclosed by the invention, the intercalated layered double hydroxide smoke inhibitor is prepared by adopting a one-step coprecipitation method or a clean hydrothermal reaction at one step; the preparation method is simple and practical; according to the obtained intercalated layered double hydroxide smoke inhibitor, smoke inhibiting groups such as molybdate anions, an octamolybdate radical, a cuprate radical and a stannate radical are arranged at an interlayer, and smoke inhibiting elements such as iron and copper are introduced into the laminated sheet, so that a good carbon forming effect is realized, the smoke generating amount can be reduced, and the smoke inhibiting effect is synergically enhanced; meanwhile, a layered double hydroxide laminated sheet forms an alkaline porous substance at high temperature; the alkaline porous substance has greater specific surface area and can effectively adsorb smog; the prepared intercalated layered double hydroxide smoke inhibitor is applied to an ordinary rubber-plastic product and a high-temperature rubber-plastic product; the maximum density (Ds, max) at low additive amount (1phr) can be reduced by 87.3 percent; the intercalated layered double hydroxide smoke inhibitor is remarkable in smoke inhibiting effect and is a smoke inhibitor material with excellent performance.

A hydrotalcite composite luminescent material with rhodamine intercalation, which pertains to abio-organic composite luminescent material. The process is preparing solution A with mole ratio of bivalence and tervalence cation M2+ / M3+=2.0-4.0; adding laser dye sulphonated rhodamine and sodium salt of dodecylbenzene sulfonic acid into mixed solution of ethanol and water and fully dissolving to obtain solution of sulphonated rhodamine and dodecyl benzene sulfone acid group containing anion with negative charge B; mixing solution A, B into solution C, preparing NaOH solution; communicating solution C and NaOH solution into full-back-liquid mixing membrane reactor to react, mixing to obtain red slurry, introducing the red slurry into hydrothermal kettle, reacting, absterging by CO2, de-ionized water and absolute ethyl alcohol and centrifugally separating, vacuum drying. Then hydrotalcite system with co-intercalation of suphonated rhodamine and dodecyl sulfone acid group is obtained. Advantages of the invention are that dye molecular is immobilized, and fluorescence quenching caused by dye aggregation is reduced.

The present invention is directed to methods for reducing SOx, NOx, and CO emissions from a fluid stream comprising contacting said fluid stream with a compound comprising magnesium and aluminum and having an X-ray diffraction pattern displaying at least a reflection at a two theta peak position at about 43 degrees and about 62 degrees, wherein the ratio of magnesium to aluminum in the compound is from about 1:1 to about 10:1. In one embodiment, the ratio of magnesium to aluminum in the compound is from about 1:1 to about 6:1. In one embodiment, the ratio of magnesium to aluminum in the compound is from about 1.5:1 to about 10:1. In another embodiment, the invention is directed to methods wherein the ratio of magnesium to aluminum in the compound is from about 1.5:1 to about 6:1.

An improved process is described for the preparation of surface modified hydrotalcite. The process comprises reacting a precursor of magnesium and aluminium in the presence of suitable alkali carbonate at high temperature. The product has a BET surface area of ≦20 m2 / gm and average particle size of ≦0.5 μm and is useful as halogen scavenger and fire retardant.