10 results about "Ammonium dimolybdate" patented technology

The application relates to the technical field of molybdenum trioxide production, and particularly discloses a preparation method of high-purity molybdenum trioxide. The method comprises the following steps: preparing a complexing impurity removing agent by taking diatomite, citric acid, ethylenediaminetetraacetic acid disodium and tartaric acid as raw materials; dissolving industrial ammonium dimolybdate to obtain an ammonium molybdate solution, adding the impurity removing agent into the ammonium molybdate solution, complexing impurities under an acidic condition, and deeply removing the impurities through flocculation and precision filtration; adjusting the alkalinity of the filtrate, and cooling and crystallizing the filtrate to obtain high-purity ammonium molybdate; and finally performing program-controlled temperature calcination in an atmosphere with a specific oxygen content by using a quartz boat coated with a composite coating on the inner wall, so as to obtain high-purity molybdenum trioxide. The application combines multi-stage purification with an accurate calcination process, can efficiently remove impurities in raw materials, and has stable process flow; the obtained molybdenum trioxide product has high purity, good crystal morphology, good process stability and good industrialization prospect.

The invention provides a preparation method of high-purity ammonium dimolybdate. The method comprises the following steps: 1, washing industrial molybdenum oxide with hot water, stirring, and carrying out suction filtration to obtain an industrial molybdenum oxide filter cake; 2, sequentially adding pure water and sodium hydroxide into the industrial molybdenum oxide filter cake, and filtering to obtain a sodium molybdate solution; step 3, adding dilute sulphuric acid into the sodium molybdate solution, precipitating, filtering, and adding dilute sulphuric acid into the sodium molybdate solution; 4, dilute sulphuric acid is added into the organic phase, then the organic phase and a sodium molybdate solution are mixed, and a molybdenum-loaded organic phase is obtained through extraction; 5, reverse extraction is conducted on the molybdenum-loaded organic phase through a reverse extraction agent, and an ammonium molybdate solution is obtained; and 6, carrying out evaporative crystallization on the ammonium molybdate solution to obtain high-purity ammonium dimolybdate crystals. According to the method, starting from industrial molybdenum oxide, the maximum impurity removal effect is fully considered in each step, the target substance is purified in the whole process, no repeated step exists, the impurity removal range is wide, the efficiency is high, the product quality is good, and ammonium dimolybdate with the purity higher than 99.99% can be stably prepared.

The invention relates to the technical field of chemical engineering, in particular to a method for recovering molybdenum from molybdenum-containing alkaline furnace ash. The method comprises the following steps: dissolving molybdenum-containing alkaline furnace ash in water, and carrying out solid-liquid separation to remove insoluble substances so as to obtain an alkaline clear solution; a molybdenum element in the alkaline clear liquid is adsorbed through first ion exchange resin, and a sodium carbonate solution is obtained; desorbing the first ion exchange resin which adsorbs the molybdenum element by using a first ion exchange resin desorption solution to obtain a first molybdenum-containing desorption solution; contacting the first molybdenum-containing desorption solution with a reducing agent to precipitate other heavy metals, and removing precipitates to obtain a first molybdenum-containing clear solution; adsorbing the molybdenum element in the first molybdenum-containing clear liquid by using a second ion exchange resin, and then desorbing the second ion exchange resin which adsorbs the molybdenum element by using a second ion exchange resin desorption solution to obtain a second molybdenum-containing clear liquid; and mixing the second molybdenum-containing clear liquid with acid for acid precipitation. According to the method, the recovery rate of the molybdenum element is high, the purity of ammonium dimolybdate is high, and economic benefits are good.

This invention discloses a process for preparing molybdenum powder by reducing molybdenum powder with ammonium molybdate doping, belonging to the technical field of molybdenum powder preparation methods. The process includes: placing a mixture of ammonium dimolybdate and molybdenum powder as raw material in a quartz crucible, covering it with a lid, and subjecting it to microwave heating treatment; cooling the treated material to obtain a microwave-treated product; and then reducing the microwave-treated product with hydrogen to obtain molybdenum powder, wherein the mass of the molybdenum powder is 10-20% of the mass of the ammonium dimolybdate. This invention can significantly reduce the production cycle and cost of producing molybdenum powder from ammonium molybdate, and obtain high-purity molybdenum powder.

The application discloses a method for preparing low-potassium molybdenum powder, which comprises the following steps: step 1, adding a small amount of sodium chloride into an ammonia leaching solution of molybdenum ore, and evaporating and crystallizing to prepare ammonium dimolybdate; step 2, preparing molybdenum oxide by calcining the ammonium dimolybdate; and step 3, reducing the molybdenum oxide by hydrogen in two stages to obtain the low-potassium molybdenum powder. The method for preparing the low-potassium molybdenum powder adopts a doping method according to the process conditions of conventional molybdenum powder production, uses a chloride (NaCl) to remove impurities potassium, and makes the potassium overflow after being vaporized and volatilized in a hydrogen reduction environment, so that the low-potassium molybdenum powder is prepared, the use of high temperature (greater than 1000 DEG C) is avoided, the low-potassium molybdenum powder is prepared by only using conventional methods at 800-900 DEG C, energy consumption is reduced, and the molybdenum powder is prevented from being caked, sintered and agglomerated.

The invention relates to the technical field of fireproof coatings, in particular to a fireproof thermal insulation coating for an SPC floor base material and a preparation method of the fireproof thermal insulation coating. The fireproof thermal insulation coating for the SPC floor base material is prepared from the following raw materials in parts by mass: 50 to 100 parts of epoxy modified acrylate, 5 to 10 parts of isobornyl acrylate, 1 to 8 parts of diethylene glycol dimethacrylate, 1 to 5 parts of diphenylmethane diisocyanate, 5 to 10 parts of graphene oxide, 5 to 10 parts of ammonium dimolybdate, 1 to 2 parts of amino silane coupling agent, 1 to 5 parts of charring agent and 0.1 to 1 part of catalyst. 1-2 parts of a flatting agent, 1-2 parts of a photoinitiator, 1-2 parts of a delustering agent and 15-25 parts of a solvent. The obtained coating has high adhesive force, good flexibility and excellent fireproof and flame-retardant performance, is especially suitable for preparing SPC floors, meanwhile, the preparation raw materials are easy to obtain, the preparation method is simple, practicability is good, the coating is suitable for large-scale application and popularization, and good industrial application prospects are achieved.

The application discloses a preparation method of a high-entropy alloy-based catalyst, a catalyst and a zinc-air battery, and belongs to the technical field of catalyst preparation. The preparation method comprises the following steps: providing iron nitrate, cobalt nitrate, nickel nitrate, manganese nitrate, ammonium dimolybdate, stannous chloride and multi-walled carbon nanotubes; dissolving the iron nitrate, the cobalt nitrate, the nickel nitrate, the manganese nitrate, the ammonium dimolybdate and the stannous chloride in a target solution to form an initial mixed solution; adding the multi-walled carbon nanotubes into the initial mixed solution to form an intermediate mixed solution; heating the intermediate mixed solution until all the liquid in the intermediate mixed solution is evaporated to form an initial powder; and performing thermal shock on the initial powder to obtain the high-entropy alloy-based catalyst.

The invention provides a method for preparing fine-grained ammonium heptamolybdate crystals by an aid crystallization method. The method specifically comprises the following steps: step 1, preparing an ammonium molybdate solution; 2, crystallizing an ammonium molybdate solution auxiliary agent; and step 3, performing reduced pressure evaporation to prepare fine-fraction ammonium heptamolybdate crystals. Molybdenum oxide is used as a raw material, ammonium heptamolybdate is formed under the synergistic effect of induced crystallization of assistant crystallization and reduced pressure evaporation, and the concentration of molybdenum in the solution is improved through reduced pressure evaporation, so that molybdate ions are induced to be converted towards a high polymerization degree direction, and formation of ammonium heptamolybdate is remarkably promoted; and the crystallization auxiliary agent can promote the formation of crystals and refine ammonium heptamolybdate crystal particles, so that a fine-fraction ammonium heptamolybdate crystal product with high purity and narrow particle size distribution is obtained.

The invention belongs to the field of powder metallurgy, and particularly discloses a method for preparing nano molybdenum-rhenium alloy powder through liquid-phase in-situ precipitation. According to the method, ammonium heptamolybdate and ammonium perrhenate serve as raw materials and are dissolved in an ammonia water solvent, then a dispersing agent, a complexing agent and a surface active agent are added, the pH is adjusted to be within the acidic range, so that molybdenum-rhenium precursors are rapidly separated out from the solution in situ, and atomic-scale mixed ammonium dimolybdate-ammonium perrhenate mixed crystals are formed. And then low-temperature calcination dehydration is conducted in the argon atmosphere, gradual reduction and alloying of oxides are sequentially achieved through a three-stage hydrogen reduction technology, and finally the nanometer molybdenum-rhenium alloy powder which is uniform in component, good in dispersity and about 160 nm in average particle size is obtained. The method is simple in process, and the prepared powder is small in particle size and concentrated in distribution, has high sintering activity and is suitable for preparing a high-performance molybdenum-rhenium alloy material.

The invention provides a method for preparing ammonium dimolybdate from ammonium heptamolybdate, and belongs to the technical field of chemical product preparation. The method comprises the following steps: weighing ammonium heptamolybdate and an ammonium source in a container according to a molar ratio, adding deionized water, stirring while heating until solids are completely dissolved, then cooling and crystallizing the solution, filtering after the crystallization is finished, and drying the filtered crystal substance to obtain ammonium dimolybdate; the ammonium source is one or more of ammonium bicarbonate, ammonium carbonate and ammonia water, and the molar ratio of the ammonium heptamolybdate to the ammonium source is equal to 1: (1.0-1.3) in terms of total ammonium in the ammonium heptamolybdate and the ammonium source. The method is short in technological process, low in energy consumption and relatively simple in preparation means, and the prepared ammonium dimolybdate product is low in impurity content and stable in quality.