41 results about "Hydroxide magnesium" patented technology

Methods for making magnesium hydroxide are described.

The invention relates to a method for preparing high dispersed magnesium hydroxide from agglomerated state magnesium hydroxide, and belongs to the technical field of the preparation of inorganic chemical industry materials. According to the method disclosed by the invention, the high dispersed magnesium hydroxide is prepared through the following steps: using agglomerated state magnesium hydroxide as a raw material, wherein the original average particle diameter is 0.1-3 microns, and the average agglomerated particle diameter is 5-50 microns, firstly, mixing the raw material with proper amount of inorganic solvent, and roasting the mixture for 0.5-6 hours at the temperature of 300-700 DEG C, so as to form dispersed superfine active magnesium oxide; then, adding the magnesia to an aqueous solution containing a dispersing agent and a morphological control agent, and performing hydration conversion for 0.5-6 hours at the temperature of 10-100 DEG C so as to obtain the high dispersed magnesium hydroxide of which the original average particle diameter is 0.1-3 microns, the average agglomerated particle diameter is 0.5-4.0 microns, the morphology is regular, and the particle diameters are homogeneous. The method disclosed by the invention is simple in technology, is mild in process, and is high in added value of a product. The magnesium hydroxide prepared by the method disclosed by the invention is regular in morphology and is good in dispersion, can be used as a basic inorganic chemical industry product to be used in the fields of flame resistance, foods, desulphurization, wastewater treatment and the like.

Magnesium hydroxide having a high aspect ratio, a production method thereof and a resin composition comprising the same.The method of producing the magnesium hydroxide having a long diameter (width) of not less than 0.5 μm and aspect ratio of not less than 10,comprising the steps of:(A) adding an alkali to and coprecipitating it with a mixed aqueous solution of a water-soluble magnesium salt and a monovalent organic acid or a salt thereof, or(B) adding an alkali aqueous solution to and coprecipitating it with an aqueous solution of a water-soluble magnesium salt and adding a monovalent organic acid or a salt thereof to the resulting product; and(C) hydrothermally treating the obtained slurry at 100° C. or higher.

The invention belongs to the field of medical biological materials and relates to composite magnesium oxide powder for dental alginate impression material used in oral orthopaedics. High-quality magnesium hydroxide and light magnesium carbonate are used as raw materials, magnesium oxide different in activity and quality is obtained in a rotary kiln or a rotational flow dynamic-state furnace through high-temperature calcination and decomposition, and the composite magnesium oxide powder is obtained through ultrafine grinding and full mixing according to a certain proportion. The prepared composite magnesium oxide powder is small in fineness, white in color, large in size, good in dispersity and adjustable in activity, is used for adjusting and controlling the setting time of the dental alginate impression material and can increase impression hardness and smoothness and decrease impression deformation.

The invention discloses an efficient magnesium hydroxide flame retardant wet-process preparation method, and relates to the technical field of wet-process mineral separation. According to the preparation method, wet purification is performed on low-grade brucite to prepare a magnesium hydroxide flame retardant, and particularly comprises the following steps: crushing brucite raw ore into gravels; putting the gravels into an overflow type ball grinder for wet ore grinding to prepare brucite slurry; performing sand removal and purification on the brucite slurry through a spiral sand remover and a hydrocyclone; removing ferric micro powder impurities, mixed during ball grinding, through a high-gradient magnetic separator, then adding a medicine for flotation classification for further purification; performing natural settling, water filtering, pressure filtering, drying and ultrafine smashing on the purified brucite slurry to prepare the magnesium hydroxide flame retardant with different particle sizes. By the adoption of a wet-process mineral separation process, the low-grade brucite can be purified, and the resource utilization rate of the brucite ore is greatly increased; meanwhile, the whole mineral separation process is completed by reasonably adopting large-sized treatment machinery, so that the mineral separation efficiency is greatly improved.

The invention discloses a method for preparing nanometer magnesium hydroxide from phosphorus ore magnesium removal waste liquor. The method specifically includes subjecting ammonia gas and the phosphorus ore magnesium removal waste liquor to further neutralizing and edulcorating reaction in a submerged circulating impinging stream reactor, and performing solid-liquid separation after the reaction so as to obtain mother liquor; adding a dispersant into the mother liquor, and continuing to feed the ammonia gas for magnesium precipitation reaction so as to reach a pH value of 10-11; performing solid-liquid separation, washing and drying after the reaction so as to obtain nanometer magnesium hydroxide powder. The nanometer magnesium hydroxide prepared by the method has the purity up to 98%, is small in particle size and regular in shape and can be widely applied to the fields of fire retardants and flue gas desulfurizing agents, and secondary utilization of resources is achieved effectively.

The invention discloses a process for preparing a magnesium hydroxide whisker and calcium sulfate by using phosphate tailings as raw materials. The process comprises the following steps: mixing phosphate tailings obtained through flotation with hydrochloric acid to react and obtaining a mixed solution containing magnesium chloride and calcium chloride after impurity removal and filtration; mixing the phosphate tailings with sulfuric acid to react and obtaining a magnesium sulfate solution after impurity removal and filtration; mixing the two solutions and obtaining a calcium sulfate precipitate and magnesium chloride filtrate after reaction and filtration; adding alkali liquor to the magnesium chloride filtrate and obtaining a liquid-solid mixture containing a basic magnesium chloride whisker after reaction and aging; adding an alkaline solution later and obtaining the magnesium hydroxide whisker after reaction and aging; returning ammonia gas recovered through gas stripping of the filtrate to the section for producing the magnesium hydroxide whisker and returning the liquid phase after gas stripping to the acidolysis section after the liquid phase is crystallized to remove ammonium chloride. The process has the beneficial effects that the phosphate tailings are used as the raw materials to produce the magnesium hydroxide whisker and the byproduct calcium sulfate, and meanwhile, higher value application of the phosphate chemical solid wastes and cleaner production are achieved by recycling surplus ammonia gas.

The invention relates to a preparation method of highly-dispersed nano-magnesium hydroxide. The preparation method comprises the following steps: dissolving tetramethylammonium hydroxide in anhydrous ethanol to prepare a 2.0-8.0mol / L solution A; preparing a soluble magnesium salt aqueous solution B; slowly adding the solution B into the solution A; and after the solution B is added and sunk under a room temperature condition, filtering, washing the filter cakes, and washing by anhydrous ethanol and drying to obtain a target product. The preparation method provided by the invention has the advantages of simple process and mild reaction condition, and can be used for synthesizing highly-dispersed nano-magnesium hydroxide which is uniform in size distribution.