4 results about "Cerium oxalate" patented technology

The invention discloses preparation of a high-uniformity cerium oxide abrasive material and application of the high-uniformity cerium oxide abrasive material in a chemical mechanical polishing solution. According to a method, cerium nitrate or cerium oxalate is used as a cerium source, a cationic or nonionic surfactant is used as a structure-directing agent, and the high-uniformity cerium oxide abrasive material is prepared in a mixed solvent system formed by water and isopropanol or water and diethylene glycol according to a specific volume ratio. The preparation method comprises the following steps: regulating the particle size and the morphology structure through a solvothermal reaction, carrying out cleaning, drying and high-temperature calcination treatment on a reaction product to obtain sphere-like cerium oxide nano-particles with high particle size concentration ratio, moderate surface roughness and good dispersity, adding cerium oxide powder into deionized water, and carrying out ultrasonic dispersion to obtain the spherical cerium oxide nano-particles. And sequentially adding a dispersing agent and amino acid while stirring, uniformly stirring, fixing the volume, and adding a pH regulator to enable the solution to be weakly acidic, thereby obtaining the chemical mechanical polishing solution. The cerium oxide submicron powder which is different in surface appearance, particle size and distribution uniformity is prepared by adjusting the solvent ratio and other reaction conditions.

The invention belongs to the technical field of organic synthesis, and particularly discloses a composite catalyst and a preparation method and application thereof in synthesis of 4-cyanopyridine, the composite catalyst comprises the following components by weight: 8-10% of an active component, 1-2% of a promoter, 88-90% of a carrier, and 0.5-1% of a performance regulator; the active component is a vanadium source and comprises ammonium metavanadate, vanadium pentoxide and sodium metavanadate; the promoter is a cerium source and comprises cerium nitrate, cerium oxide and cerium oxalate; the carrier is a titanium source and comprises titanium dioxide, tetrabutyl titanate, titanyl sulfate and isopropyl titanate; the performance regulator is graphene quantum dots. According to the composite catalyst and the preparation method thereof, the composite catalyst is applied to the synthesis process of 4-cyanopyridine, a target product can be efficiently prepared in a high-selectivity and low-energy-consumption mode, and then the composite catalyst has the practical value and application potential of industrial continuous production.

This utility model relates to the field of rare earth oxide production technology and discloses a rare earth oxide production equipment, including a base. A heating plate is fixedly connected to the inner wall of the base, and a support leg is fixedly connected to the bottom of the base. An electric push rod is fixedly connected to the outer wall of the support leg, and a top cover is fixedly connected to the output end of the electric push rod. A material leveling mechanism and a material turning mechanism are arranged inside the top cover. The material leveling mechanism includes a motor, which is fixedly connected to the top of the top cover. A rotating shaft is fixedly connected to the output end of the motor, and a boss is fixedly connected to the bottom of the rotating shaft. In this utility model, the design of the material leveling mechanism enables cerium oxalate to be evenly dispersed and spread on the heating plate, effectively avoiding local accumulation and ensuring uniform heating of the material. This design not only improves the heat transfer efficiency of cerium oxalate but also further optimizes the stability and consistency of the overall heating process.

The present invention relates to a method for green recovery of rare earths from spent FCC catalysts using a high-concentration aluminum salt system. The method comprises the following steps: first, a high-concentration aluminum salt solution-hydrogen peroxide system is used to reduce and leach the spent FCC catalyst in a two-step process to obtain a leachate containing rare earth elements lanthanum and cerium; second, the rare earth-containing leachate is subjected to P204 extraction and hydrochloric acid stripping to separate and purify the rare earths, obtaining a purified rare earth solution; and finally, precipitation with oxalic acid to obtain a high-purity lanthanum oxalate-cerium mixed product. This method achieves green, clean, and efficient recovery of rare earth elements lanthanum and cerium from spent FCC catalysts. The method achieves an extraction efficiency of over 90% for rare earths from spent FCC catalysts, a purity of over 99%, and environmentally friendly reagents such as the aluminum salt and hydrogen peroxide used.