47results about "Molybdeum compounds preparation" patented technology

High purity ammonium dimolybdate or molybdenum oxide is produced by the pressure oxidation of low grade molybdenite concentrates or molybdenum intermediates. The process entails nearly complete oxidation of the sulfide minerals while optimizing the process chemistry and autoclave conditions to solubilize as little of the molybdenum values as possible. The autoclave discharge 12 is then subjected to a leaching step, either an alkaline leach 50, 400 or ammonium leach 250 process, before or after a liquid/solid separation step 20, 220, 410. The solution is then subjected to (a) filtration 60, 410, solvent extraction 70, 440, crystallization 90, 450, and calcination 120, 480 or (b) filtration 260, 280, crystallization 290, and calcination 320 to produce a product suitable for chemical-grade molybdenum oxide 125, 325, 485.

A method for the extraction and purification of molybdenum, the method comprising the steps of: transferring an irradiated fuel solution to an extraction system, the irradiated fuel solution comprising iodine and molybdenum and other fission products, the extraction system comprising at least one sorbent column; passing the irradiated fuel solution upwards through the at least one sorbent-containing extraction column; directing the irradiated fuel solution towards a fuel management system by means of at least one discharge alignment valve; directing the extraction column eluate towards an iodine removal system; removing the iodine from the extraction column eluate; purifying the extraction column eluate; and collecting the purified eluate. Also disclosed is an apparatus for accomplishing the aforementioned method.

A system and method for producing molybdenum oxide(s) from molybdenum sulfide are disclosed. The system includes a pressure leach vessel, a solid-liquid separation stage coupled to the pressure leach vessel, a solvent-extraction stage coupled to the solid-liquid separation stage, and a base stripping stage coupled to the solvent-extraction stage. The method includes providing a molybdenum sulfide feed, subjecting the feed to a pressure leach process, subjecting pressure leach process discharge to a solid-liquid separation process to produce a discharge liquid stream and a discharge solids stream, and subjecting the discharge liquid stream to a solvent extraction and a base strip process.

Provided are methods to separate an isotope from a first solution including uranium. The methods may include (a) cleaning the first solution to form a second solution including the uranium and a third solution including the isotope; (b) oxidizing the third solution to form an oxidized isotope; and (c) separating the oxidized isotope.

Process for recovering molybdate or tungstate from an aqueous solution, in which molybdate or tungstate is bound to a water-insoluble, cationized inorganic carrier material from the aqueous solution at a pH in the range from 2 to 6, the laden carrier material is separated off and the bound molybdate or tungstate is liberated once again into aqueous solution at a pH in the range from 6 to 14. The process is suitable for recovering molybdate or tungstate in the delignification of pulp with hydrogen peroxide in the presence of molybdate or tungstate as catalyst. The recovered molybdate or tungstate can be recycled to the delignification.

The invention belongs to the field of non-ferrous metal recovery, and particularly relates to a recovery method of a waste SCR denitration catalyst. The recovery method comprises the steps of pretreatment, TiO2 separation, extraction and purification, titanium recovery, vanadium recovery, tungsten/molybdenum recovery and the like. The recovery method is capable of recycling a several precious recovery products such as V2O5, ammonium tungstate/ammonium molybdate and BaTiO3 from the waste SCR denitration catalyst. The invention provides an effective technical scheme, and efficient resource utilization of the waste SCR denitration catalyst can be realized.

The invention relates to a method for recycling ammonium molybdate from waste molybdenum catalysts. The method includes the following steps of 1, conducting sampling and measuring the mass content ofmolybdenum sulfide in the waste molybdenum catalysts; 2, preparing waste molybdenum catalyst powder; 3, adding an appropriate quantity of ionic liquids into a reaction still to serve as a reaction medium, turning on a stirring device of the reaction still, sequentially putting the catalyst powder, ammonium hydroxide and hydrogen peroxide into the reaction still, and closing the reaction still forcarrying out a reaction to obtain a reaction product; 4, filtering and separating the reaction product to obtain a filter cake and a filtrate; 5, conducting extraction separation on the filtrate, thenadding deionized water into the filtrate, extracting ammonium molybdate from the ionic liquids into water to obtain an ammonium molybdate aqueous solution and an ionic solution; 6, placing the ammonium molybdate aqueous solution in a crystallizer for crystallization to obtain ammonium molybdate crystals. The method for recycling ammonium molybdate from the waste molybdenum catalysts has the advantages that the craft process is environmentally friendly and free of pollution, the consumption is low, and the recycling rate of molybdenum is high.

The invention discloses a method for preparing high-purity molybdate from a rough sodium molybdate solution. The method mainly comprises the following steps: adding a proper amount of inorganic acid into the rough sodium molybdate solution to perform primary acid regulation until the pH value of the solution is regulated to be 4-5, and stirring the solution for 5 minutes; adding a proper amount of transition additive, and stirring and mixing for 10 minutes; adding a proper amount of inorganic acid to perform secondary acid regulation, regulating the pH value of the solution to be 1-2, and uniformly stirring the solution for 20-30 minutes; performing centrifugal filtration, washing a obtained washing solution for solid, filtering again, and drying to obtain solid, namely high-purity molybdate; and adsorbing centrifugal filtered solution and washing solution with weakly basic macro porous anion resin, and recycling valuable metal molybdenum. The method can realize effective separation of molybdenum, calcium and magnesium in the rough sodium molybdate solution, so that the high-purity molybdate is prepared.

The invention discloses a method for synergistic recovery of molybdenum and rhenium from a molybdenum concentrate roasting eluent, which belongs to the technical field of comprehensive recycling of metal rhenium and molybdenum. The method comprises the following steps: mixing the molybdenum smelting waste acid and a pretreatment agent, stirring a mixture, and then performing solid-liquid separation; introducing a filtrate to an exchange column containing weakly basic anion exchange resin A to adsorb rhenium, and introducing the adsorbed liquid in an exchange column filled with the weakly basicanion exchange resin B to adsorb molybdenum; performing desorption with the adsorbed saturated A column, collecting a desorption solution, and performing evaporation crystallization to obtain an ammonium perrhenate product; performing desorption with the adsorbed saturated B column, collecting the desorption solution, and performing evaporation crystallization to obtain an ammonium molybdate product. In a pretreatment step in the process, no rhenium loss is generated, the molybdenum loss rate is less than 8%, after treatment, the liquid is introduced into ion exchange, compared with the direct adsorption process, the method can increase the adsorption capacity of the resin A to the rhenium, and by changing the acidity of the solution and the impurity ion content, the high-efficiency adsorption of the resin B to the molybdenum is achieved.

In a delignification of pulp with hydrogen peroxide catalysed with molybdate, molybdate can be recovered by bringing the aqueous solution containing molybdate into contact with a carrier material that comprises a layered silicate ion-exchanged with a quaternary ammonium salt at a pH value ranging between 2 and 7 and subsequent flotation, without the need to add a tenside for the flotation.

The invention provides a preparation method of an amorphous MoSx (x=2-4) monolayer nanosheet. The method includes: taking the interlayer of layered double hydroxides (LDHs) as the microreactor, and firstly preparing an MoS4<2-> intercalated LDHs compound; then performing low temperature calcination to enable low temperature decomposition of MoS4<2-> into Mo3S13 nanoclusters, then conducting arrangement at the interlayer to form MoSx monolayer nanosheet, and then carrying out acid dissolution to remove mixed metal oxides (MMO), thus obtaining the amorphous MoSx monolayer nanosheet. The preparation method is simple, has mild reaction conditions, and is easy to realize, does not use organic reagents, is safe, green and environment-friendly. The obtained amorphous MoSx is a monolayer and porous nanosheet structure, has large specific surface area, also has a large number of active sites and defects on the surface, and has excellent electrocatalytic hydrogen evolution performance.

The invention discloses a comprehensive utilization system of a spent catalyst. The comprehensive utilization system of the spent catalyst is characterized by comprising a deoiling furnace, a rotary kiln, a four-stage countercurrent device, a stirring tank I, a plate-and-frame filter I, a precipitation tank I, a plate-and-frame filter II, a stirring tank II, a centrifuge I, ion exchange resin, anextraction device, a back extraction device, a precipitation tank II, a centrifuge II and a washing tank. The comprehensive utilization system of the spent catalyst is low in process cost, green and environment-friendly, and capable of effectively recycling useful components in the residual oil hydrotreating spent catalyst to obtain industrial steam, nickel-aluminum powder, ammonium metavanadate,high-purity molybdic acid, anhydrous sodium sulfate, distilled water and the like, wherein the high-purity molybdic acid can be obtained without repeated separation processes, and the purity of the high-purity molybdic acid can reach 99. 9%.

A method for recovering technical-grade molybdenum from diluted acid leaching solutions (PLS) that have a high arsenic concentration is disclosed. The method includes: (a) bringing a pre-filtered acid leaching solution (PLS), originating from the leaching of smelter dust, into contact with an anionic ion-exchange resin; (b) washing the loaded resin with water; (c) extracting molybdenum from the ion-exchange resin with an alkaline ammonium regenerant solution to form ammonium molybdenum in solution; (d) washing the unloaded resin with water; (e) adding iron and/or magnesium salts to the recovered ammoniacal solution to obtain a precipitate which is transferred to the arsenic abatement step and a solution containing ammonium molybdate in solution; (f) adding sulphuric acid to the arsenic-free ammoniacal solution in order to precipitate the moylbdenum in the form of ammonium molybdate; (g) separating the precipitate by filtering the molybdate and re-circulating the solution obtained with the initial PLS solution; (h) calcining the separated precipitate to obtain ammonia and molybdenum trioxide; and (i) recovering the released ammonia for its subsequent use in the method as a recirculated regenerant solution.

The invention discloses a production process of ammonium molybdate, which relates to the technical field of ammonium molybdate production, and comprises the following steps: (1) washing and filter-pressing molybdenum calcine, mixing the filter-pressed molybdenum calcine with a leaching agent, adjusting the pH value to 10-11.5, and keeping the temperature for 2-3 hours under the conditions of oxygen partial pressure of 20 atm and temperature of 150-170 DEG C to obtain a sodium molybdate solution; (2) adding quaternary ammonium salt into the ammonium molybdate solution, extracting molybdenum under an alkaline condition, and adding ammonium bicarbonate into the extracting solution to obtain an ammonium molybdate solution; (3) adding calcium oxide into the extracting solution; (4) evaporating and crystallizing the ammonium molybdate solution to obtain ammonium dimolybdate; and (5) adding acid into the crystallization mother liquor after the ammonium dimolybdate is prepared for precipitation to obtain ammonium tetramolybdate, adjusting the pH value of the ammonium tetramolybdate solution to 1.5-2.0 by using nitric acid, and separating out ammonium tetramolybdate crystals. The method has the beneficial effects that the method has the advantages of short process flow, low consumption of chemical reagents and high resource adaptability.

The invention discloses a method for preparing an ammonium polymolybdate solution based on bipolar membrane electrodialysis. The method comprises the following steps: taking an ammonium molybdate solution as a raw material and adopting a bipolar-membrane electrodialysis system with a two-chamber bipolar membrane electrodialysis membrane stack to remove one part of ammonium ions in the ammonium molybdate solution and reducing the pH (Potential of Hydrogen) value in a bipolar-membrane electrodialysis process under the action of a direct-current electric field force; directly obtaining the ammonium polymolybdate solution in an acidifying chamber of the bipolar-membrane electrodialysis system. According to the method disclosed by the invention, organic acid does not need to be consumed and impurity anions are not introduced; the method has the advantages of short flow, high direct recovery rate, low power consumption, environment friendliness and easiness of realizing industrialization.

A copper/molybdenum separation processor is provided featuring a slurry/media mixture stage configured to receive a conditioned pulp containing hydrophobic molybdenite and hydrophilic copper, iron and other minerals that is conditioned with sodium hydrosulfide together with an engineered polymeric hydrophobic media, and provide a slurry/media mixture; and a slurry/media separation stage configured to receive the slurry/media mixture, and provide a slurry product having a copper concentrate and a polymerized hydrophobic media product having a molybdenum concentrate that are separately directed for further processing. The slurry/media mixture stage include a molybdenum loading stage configured to contact the conditioned pulp with the engineered polymeric hydrophobic media in an agitated reaction chamber, and load the hydrophobic molybdenite on the engineered polymeric hydrophobic media.

The invention discloses a device and a method for preparing ammonium molybdate from molybdic acid. The device comprises multiple stages of countercurrent absorption and concentration devices. The molybdic acid is used for carrying out circulating absorption on ammonia-containing tail gas after size mixing is carried out, and is dissolved to obtain ammonium molybdate solution with the saturation concentration along with ammonia gas absorption, the ammonia-containing tail gas is switched to a previous stage to be reabsorbed after the certain requirements are met by absorption liquid of a backward stage, and accordingly the solution concentration of the absorption liquid can be increased; the ammonium molybdate solution is transported to main processes to be used after the technological requirements are ultimately met by absorption liquid of a first stage. Compared with the prior art, the device and the method have the advantages that the amount of labor of staffs can be reduced; the production cost can be lowered to a great extent, strong ammonia water needs to be supplemented to carry out dissolution in the original technologies, but the molybdic acid can be directly dissolved by the ammonia-containing tail gas, and the requirements of emission standards can be met by ammonia-containing tail gas after absorption treatment is carried out on the ammonia-containing tail gas; the device and the method are low in treatment cost, are safe and environmentally friendly and have high economic values.