34results about How to "High recovery rate of rare earth" patented technology

The invention relates to a new method for preparing rare earth chloride by using Baiyunebo rare earth concentrate and belongs to the field of wet-process metallurgy. The invention comprises the following steps: performing thermal decomposition, wherein a raw material used is Baiyunebo mixed rare earth concentrate with a grade of 60 to 80 percent; leaching in hydrochloric acid, namely leaching oreobtained after thermal decomposition in hydrochloric acid; performing alkaline decomposition, namely decomposing filter residue obtained after leaching in hydrochloric acid with solution of sodium hydroxide; washing, namely washing the ores obtained after alkaline decomposition with water till the pH value is 7 to 9, and recovering fluorine and phosphorus from washing solution; performing primaryneutralization, namely mixing hydrochloric acid leachate and water washing residue, and neutralizing till the pH value is 0.5 to 2.5; and performing secondary neutralization, namely neutralizing the filtrate obtained by the primary neutralization till the pH value is 4 to 5, wherein the filtrate of the secondary neutralization is solution of rare earth chloride. The method has the advantages of facilitating recovery of other elements, avoiding waste gas, waste water and waste residue, along with small alkali consumption, stable process and high rare earth recovery rate of more than or equal to 95 percent.

The invention relates to a method for cleanly and efficiently extracting rare earth elements from waste fluorescent powder, and belongs to the technical field of recycling the waste rare earth fluorescent powder. The waste fluorescent powder and alkali are mixed evenly at the mass ratio of 1:(0.1-10), and a mixture is obtained; the obtained mixture is heated to the temperature of 300-800 DEG C atthe microwave power of 1-5 kW to be subjected to low-temperature calcination for 0.5-1 h, and a calcined material is obtained; the calcined material is ground into powder, then a water solution is added according to the liquid-solid ratio of (1-6):1 ml / g, water leaching is carried out at the temperature of 25-80 DEG C for 5-30 min, after solid-liquid separation, water leaching residues and aluminum-containing aqueous leachate are obtained, and the water leaching residues are repeatedly water-leached 1-5 times; and a hydrochloric acid solution is added into the water leaching residues accordingto the liquid-solid ratio of (5-10):1 ml / g, acid leaching is carried out at the temperature of 25-80 DEG C for 0.5-2 h, and after solid-liquid separation, leaching residues and rare-earth-containingleachate are obtained. The method has the beneficial effects of being low in cost and high in rare earth recovery rate, achieving energy saving and environmental friendliness and the like.

A method for separating and recovering rare earths from waste rare earth luminescent materials. The process steps are: collection of waste rare earth luminescent materials, including rapid identification of rare earth fluorescent lamps and their dismantling and breaking, crushing of CRT displays, and stripping of waste rare earth luminescent materials from glass substrates and collection; pretreatment of waste rare earth luminescent materials, including demercury oxidation precipitation, alkali fusion and acid hydrolysis; extraction and separation of rare earth elements to obtain rare earth chloride enrichment; extraction and purification of rare earth elements to obtain high-purity rare earth chlorides; rare earth elements Precipitation and separation of rare earth oxalate or rare earth carbonate precipitates; rare earth oxalate or rare earth carbonate precipitates are roasted to obtain high-purity rare earth oxides. This method realizes the separation of rare earth elements Ce, Eu, Tb, Y and impurity elements such as Mg, Ba, Ca, and the complete separation and recovery of light, medium and heavy rare earth elements, and purifies to obtain high-purity rare earth oxides, so that resources are comprehensively recovered Utilization, the technological process is reasonable, economical and practical, the recovery rate of rare earth is high, and the added value of the product is high.

The invention provides a method for recovering rare earth from rare earth-containing wastewater. The method comprises the following steps: 1, allowing the rare earth-containing wastewater to contact with an alkaline precipitating agent capable of precipitating rare earth metal elements, and carrying out solid-liquid separation after settlement to obtain a first solution and a rare earth precipitate; and 2, allowing the rare earth precipitate to contact with an aqueous solution containing hydrofluoric acid, and carrying out solid-liquid separation after settlement to obtain a second solution and rare earth fluoride. The method allows the rare earth metal elements to be effectively recovered, the recovery rate of the rare earth metal elements to be high and rare earth and fluoride in a raffinate obtained after recovery to reach environmental protection standard requirements, and the final raffinate subjected to an acid-base neutralization reaction is basically neutral and basically has no pollution to environment; and the rare earth fluoride obtained after recovery through the method is purified rare earth, can be used for molecular sieve modification, and can also be used in production of arc carbon rods and special steel alloys as an additive.

The invention discloses a method for removing aluminum from rare-earth feed liquid, belongs to rare-earth feed liquid treatment technology and aims to provide the method for removing the aluminum from the rare-earth feed liquid, of which the aluminum-removing effect is good, the aluminum-removing cost is low, the rare-earth recovery rate is high, the operation and control are convenient, the process is simple and the investment in equipment is small. The key point of the technical scheme mainly comprises the following steps of: (1) preparing an organic phase from 15 to 25 volume percent of naphthenic acid and 15 to 25 volume percent of alcohol-kerosene; (2) adding the prepared organic phase and the rare-earth feed liquid into a stirring tank in a volume ratio of 2-5:1, starting the tank, stirring and uniformly mixing; (3) adding alkaline solution into the mixed liquid obtained in the step (2) with stirring, wherein the total number of moles of the added alkali is 50 to 100 percent of that of rare-earth elements in the rare-earth feed liquid; and (4) after adding the alkaline solution, continuously stirring for a certain time, stopping stirring and standing for a certain time, wherein the solution is separated into an aqueous phase and an organic phase and the aqueous phase is the rare-earth feed liquid from which the aluminum is removed. The method is applied to aluminum removal for the rare-earth feed liquid.

The extraction and separation method for rare-earth element comprises: with rare-earth solution contained a plurality of rare-earth elements as material, preparing mixed extractant with the non-saponifiable P204 and one or two from P507, P229, P350, TBP, C272, C301, C302 and HEOPPA; in the mixed solution with rare-earth sulfate solution, or rare-earth sulfate and rare-earth chloride solution and rare-earth nitrate solution, extracting and separating rare-earth elements. This invention eliminates saponification to overcome pollution, reduces acidity to improve rare-earth concentration, and decreases the main material consumption more than 30% compared with the technique with NH4HCO3 and P507.

The invention relates to a method for recovering rare earth from low-concentration rare earth solution through prussian blue colloidal nanoparticles (PB-CNP). The method comprises the following steps: firstly synthesizing a stable PB-CNP colloidal solution, loading into a bag produced by a dialysis membrane, enabling a dialysis bag containing PB-CNP suspension to be in contact with rare earth material liquid (the pH value is 4-7), and enabling rare earth ions to pass through membrane holes to be in contact with the PB-CNP for being adsorbed. Dilute acid solution is used for desorbing the rareearth from the PB-CNP suspension which absorbs the rare earth ions, thereby achieving the purpose of recovering the rare earth. The PB-CNP suspension and the rare earth material liquid can also be arranged in different channels on the two sides of the membrane of a membrane component for flowing in a countercurrent way, thereby achieving the high-efficient enrichment effect. The method has the advantages of simple process, large rare earth loading amount, high rare earth recovery rate and the like, and can be widely used for the rare earth material liquid of rare earth mines and separation factories; and furthermore, by adopting the method, the rare earth ions in low-concentration rare earth wastewater can be completed removed and recovered, thereby having wide application prospects.

The invention relates to a preparation method of low-thorium lutetium oxide, comprising the following steps of: firstly carrying out 3-10 level of primary countercurrent extraction on lutetium oxide extracted from a solvent as a raw material by adopting an isooctanol or kerosene solution of 0.5-2.0mol / L of N235 extracting agent, and then carrying out 3-10 level of countercurrent washing selectivebackextraction on organic phases of extracted thorium by adopting 0.1-2mol / L of alkali abluent solution; then separating the low-thorium lutetium oxide by a kerosene solution of 0.1-1.0mol / L of another extracting agent, carrying out 3-10 level of countercurrent washing selective backextraction on the organic phases of the extracted thorium by adopting 0.5-2mol / L of acidic abluent solution, carrying out oxalic precipitation, washing and dehydration on aqueous-phase lutetium oxide after thorium removal, and burning at the condition of 750-1000 DEG C to obtain a product, namely, the low-thorium lutetium oxide. In the method, rare earth and thorium are thoroughly separated, and the organic extracting agent is low in price.

The invention discloses a decomposition method for rare earth ore concentrate. The decomposition method comprises the following steps that the rare earth ore concentrate and 65%-85wt% of concentratedsulfuric acid are mixed in a reaction container, and then react at 150-185 DEG C to obtain a reaction product, wherein the dosage ratio between the rare earth ore concentrate and the concentrated sulfuric acid is 1kg: (7.8-9) L, and the reaction container is not a roasting device; the reaction product is subjected to solid-liquid separation treatment to obtain a first filter residue and a first filtrate; and the first filter residue is washed with water, and then is subjected to solid-liquid separation treatment to obtain a second filter residue and a second filtrate. According to the decomposition method, the generation of waste gas and waste residues is reduced while the high rare earth recovery rate can be kept.

The invention relates to a method for precipitating crystal heavy-rare-earth carbonate, wherein pH of heavy-rare-earth chlorid solution is adjusted to 5.0 to 5.2 by the 8-10% carbon-ammonia water, adding polyacrylamide saturated-water solution in which the volume is 1-3 per thousand of that of heavy-rare-earth chlorid solution, filtering, and the filtrate is diluted to 0.4 to 0.5 M by water, adding eavy-rare-earth carbonate, as seed crystal, agitating to uniformly mix, then precipitating by 8-10% carbon-ammonia water, ending precipitating when pH is 6.2, adding water to 80-90% of volume of the precipitating container, stopping the press water for 12- 24 hours, washing the precipitate for 2 -3 times, filtrating, and crystal heavy-rare-earth carbonate is obtained. The invention has simple operation, low cost, high yield of heavy-rare-earth and good-quality product which contains low-water and low calcium carbonate, chloride ion or the like, is easy to filtrate, having convenient packaging, stacking and trasportation, and small contamination.

The invention discloses a technique of improving rare earth recovery rate and fluorite grade in tailings, and the technique of improving rare earth recovery rate and fluorite grade in tailings comprise the following steps of : (1) mixing foam and mixing tailings are obtained through level one roughing, multistage of scavenging and multistage of refined selection of the tailings raw material; (2) total rare earth enrichment content and total fluorite enrichment content are obtained by separating the mixing foam; (3) rare earth concentrate is obtained through the level one roughing, multistage of scavenging and multistage of refined selection of the total rare earth enrichment content; (4) fluorite concentrate is obtained through the level one roughing, multistage of scavenging and multistage of refined selection of the total fluorite enrichment content. The technique of improving rare earth recovery rate and fluorite grade in tailings is capable of improving rare earth recovery rate and fluorite grade in tailings.

The invention discloses a recovery method of rare earth elements in NdFeB (neodymium iron boron) waste materials, belonging to the technical field of recovering of rare earth resource. The recovery method comprises the following steps: (1) evenly mixing aluminum fluoride powder and cryolite powder according to the mass ratio of 1:1-1:10, to obtain a cryolite-aluminum fluoride mixture; (2) crushing the NdFeB waste materials into granules with granule size of 4-6mm and burying into the cryolite-aluminum fluoride mixture; (3); putting cryolite-aluminum fluoride mixture with buried NdFeB waste materials into an electric furnace and reacting for 3-12h at the temperature of 900-1200 DEG C; and (4) conducting solid-liquid separation to the product obtained after reaction to obtain solid residue and fused salt respectively, wherein the solid residue is waste steel, and the fused salt is a rare earth fluoride-cryolite-aluminum fluoride mixture. The unoxidized rare earth elements in the NdFeB waste materials can be selectively extracted through aluminum fluoride, rare earth oxidized into oxides can be better dissolved by cryolite, and therefore the recovery rate of rare earth can be greatly improved.

The invention relates to a process method for recovering rare earth from a cerium oxide waste material. The process method is characterized in that the cerium oxide waste material with 70-85wt% of REO is screened through a sieve with the mesh being 100 to remove solid impurities such as weeds and crushed stones, 1-1.4 times the theoretical amount of sulfuric acid and not less than 1-1.4 times the theoretical amount of FeSO4 are added, and a mixture is heated to 45 DEG C to 55 DEG C under continuous stirring; then leaching is conducted for 1 h to 1.5 h, solid-liquid separation is conducted, and a primary leaching solution is obtained; and the primary leaching solution is neutralized with MgO and subjected to impurity removal, then secondary solid-liquid separation is conducted, and a secondary leaching solution is obtained. The process method has the beneficial effects that the process method is simple and feasible, capable of being used easily on a large scale and high in rare earth recovery rate, and the recovery rate of the rare earth element in the secondary leaching solution is higher than 80%.

The invention discloses a beneficiation method for recovering uranium from rare earth ores. In the method, the uranium-containing rare earth ore is finely crushed and then classified, and the coarse-grained ore and fine-grained ore are pre-concentrated by a heavy medium cyclone and a strong magnetic separator respectively; Select rare earth minerals, then flotation uranium minerals, flotation uranium concentrates are regrind to further improve the uranium grade through weak magnetic iron removal; the scavenging tailings in the flotation process are regrind and then the uranium minerals are further separated and enriched by gravity separation, Gravity-separated uranium concentrate is then subjected to strong magnetic separation to improve the uranium grade. The final uranium concentrate has a rate of 5.50%, a uranium grade of 0.27%, and a recovery rate of 71.44%. This method can efficiently recover valuable rare earth ore without affecting the recovery. Uranium resources, reduce the radioactive harm to the environment.

The invention discloses a method for recovery of rare earth by low concentration rare earth solution extraction. The method uses a rare earth solution containing heavy and middle rare earth as raw material liquid, and comprises the following steps: subjecting the raw material liquid to a first extraction by using a first organic phase of an acidic phosphorous extractant with PKa value higher than 4, so as to obtain a first loading organic phase and a first raffinate; subjecting the first raffinate to a second extraction by using a second organic phase of an acidic phosphorous extractant with PKa value less than 3.5, o as to obtain a second loading organic phase and a second raffinate; and conducting reverse extraction to recover the rare earth in the first loading organic phase and the second loading organic phase, so as to obtain high concentration chlorination rare earth solution. The method for recovery of rare earth by low concentration rare earth solution extraction has the advantages of shortened process flow, improved rare earth recovery, reduced production cost and no emission of ammonia nitrogen wastewater, realizes clean and efficient extraction of low concentration rare earth solution, improves the utilization of rare earth resources, reduces pollutant emission and chemical raw material consumption, and effectively protect the environment.