A lactic acid adsorbent includes at least one of a layered double hydroxide that contains multiple metal hydroxide layers and also contains anions and water molecules held between the metal hydroxide layers, or a layered double oxide that is an oxide of a layered double hydroxide. The metal hydroxide layers contain divalent metal ions M.sup.2+ and trivalent metal ions M.sup.3+, mole ratio (M.sup.2+/M.sup.3+) of the divalent metal ions M.sup.2+ to the trivalent metal ions M.sup.3+ in a layered double hydroxide is 1.9 to 3.6, and the mole ratio in a layered double oxide is 1.8 to 3.6.

A hydrotalcite-like granular material having a grain size of 0.24 mm or larger is produced by drying a material that contains at least a hydrotalcite-like substance and that has a water content of 70% or lower at equal to or lower than a temperature at which the hydrotalcite-like substance is dehydrated of crystal water contained therein, preferably at 90° C. or higher and 110° C. or lower, such that the resulting hydrotalcite-like granular material has a water content of 10% or higher. In this manner, a hydrotalcite-like granular material that has a stable morphology and a high anion exchange performance and that can be produced at a low cost can be produced.

The invention relates to the metallurgical industry, specifically to the acid treatment of red mud obtained in the process of producing alumina, and can be used in technologies for recycling waste from alumina refinery holding ponds. The method for the acid treatment of red mud involves leaching using a leaching agent comprised of water-soluable aliphatic carbonic acids having fewer than 3 carbon atoms per molecule, filtering the solution, and separating the recoverable end products. To ensure a high level of recovery of valuable components and the increased productivity of the process, leaching is conducted with the addition of red mud in portions and with the control of pH values, and when a target pH value of between 2.3 and 3.8 is reached, no more red mud is added, and once leaching is complete, the solution is kept at a given leaching temperature for no less than one hour.

The present invention disclosed use of lactam as a solvent in the preparation of nanomaterials by precipitation method, sol-gel method or high temperature pyrolysis. These methods are able to recycle lactam solvent, which meet requirements of environmental protection.

A method for effectively removing minute impurities of 1 μm or less in size that are present on a surface of an aluminum nitride single-crystal substrate without etching the surface includes scrubbing a surface of an aluminum nitride single-crystal substrate using a polymer compound material having lower hardness than an aluminum nitride single crystal, and an alkali aqueous solution having 0.01-1 mass % concentration of potassium hydroxide or sodium hydroxide, the alkali aqueous solution being absorbed in the polymer compound material.

It discloses a method for preparing a magnesium-aluminum hydrotalcite-loaded nano zero-valent iron material for specifically removing perfluorooctanoic acid in a water environment and an optimized process for removing perfluorooctanoic acid thereby, and relates to the technical field of removing persistent organic pollutants in water using adsorption method and oxidation-reduction method and, in particular, to a composite material prepared by loading a nano zero-valent iron on magnesium-aluminum hydrotalcite using liquid phase reduction method.

Separators, electrochemical cells and methods are provided, to improve operation of cells such as metal-ion batteries and fuel cells. Separators comprise a porous, ionically conductive film including layered double hydroxide(s) (LDHs), which are functional ceramic additives, removing potentially harmful anions from the electrolyte by incorporating them into the LDH structure of positively-charged sheets with intermediary anions. For example, anions which are electrolyte decomposition products or cathode dissolution products may be absorbed into the LDH to prevent them from causing damage to the cell and shortening the cell's life. LDHs may be incorporated in the separator structure, coated thereupon or otherwise associated therewith. Additional benefits include dimensional stability during thermal excursions, fire retardancy and impurity scavenging.

Producing a filtration body formed of a layered double hydroxide having a crystallite size of 20 nm or less carried on a carrier including a thermally fusible fiber is described. The carrier is prepared that has a first mesh carrier having a first mesh size and a second mesh carrier provided above the first mesh carrier. The second mesh carrier has a second mesh size larger than the first mesh size. A layered double hydroxide in the form of granules is supplied toward the second mesh carrier. The first mesh carrier carries the layered double hydroxide that has passed through the second mesh carrier. The carrier is shaken so that a portion of the layered double hydroxide (e.g., at least one granule) passes through the first and second mesh carriers. Thereafter, the layered double hydroxide carried on the first mesh carrier is adhered by thermally fusing the thermally fusible fiber.

The present invention discloses a crystalline aluminum phosphite, a preparation method thereof and an application thereof as or for the preparation of a flame retardant or a flame retardant synergist. The preparation method has the following processes: 1, reacting aluminum hydrogen phosphite with an aluminum-containing compound in water at 80-110° C. to obtain a precipitate in the presence of no strong acid or a small amount of strong acid; 2, washing and filtering the precipitate; 3, drying the precipitate at 100-130° C.; 4, continuously heating the dried solid step by step at a low speed, where the material temperature is increased to not exceeding 350° C. from room temperature at about 5-10 h, with a temperature rise rate not exceeding 5° C./min. Compared with amorphous aluminum hydrogen phosphite, the crystalline aluminum phosphite has a higher thermal decomposition temperature, lower water absorption and weaker acidity, and can be synergistic with diethyl aluminum hypophosphite to achieve better flame retardant property and thus, is used for a halogen-free flame retardant component of high polymer materials.

The present invention discloses a crystalline aluminum phosphite, a preparation method thereof and an application thereof as or for the preparation of a flame retardant or a flame retardant synergist. The preparation method has the following processes: 1, reacting aluminum hydrogen phosphite with an aluminum-containing compound in water at 80-110° C. to obtain a precipitate in the presence of no strong acid or a small amount of strong acid; 2, washing and filtering the precipitate; 3, drying the precipitate at 100-130° C.; 4, continuously heating the dried solid step by step at a low speed, where the material temperature is increased to not exceeding 350° C. from room temperature at about 5-10 h, with a temperature rise rate not exceeding 5° C./min. Compared with amorphous aluminum hydrogen phosphite, the crystalline aluminum phosphite has a higher thermal decomposition temperature, lower water absorption and weaker acidity, and can be synergistic with diethyl aluminum hypophosphite to achieve better flame retardant property and thus, is used for a halogen-free flame retardant component of high polymer materials.