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

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 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.

A method for extracting and recovering rare earth elements from waste phosphor comprises the following steps: (1) concentrated sulfuric acid is added into the waste phosphor, the mixture is uniformly mixed and placed into a high-temperature furnace for roasting, and rare earth is converted into a sulfate form; (2) a solid product after roasting is leached by water, rare earth sulfate enters the water and filtered, a leaching solution after filtering is separated from leaching residues; (3) oxalic acid is added into the leaching solution, pH is adjusted, rare earth is precipitated in a oxalic acid rare earth form, and rare earth oxide is obtained after filtering, drying and roasting. According to the method, the waste phosphor is subjected to processes of sulfatizing roasting, leaching, oxalic acid precipitation, oxalic acid rare earth roasting and the like to recover the rare earth elements in the waste phosphor, the process is simple, the operation is convenient, the cost is lower and the rare earth recovery rate is high.

The invention relates to a monazite ore comprehensive utilization and recovery process, wherein monazite and xenotime and other associate minerals are completely separated through mineral dressing, and alkali decomposition treatment, preferred dissolving, complete dissolving and extraction separation are used, such that the recovery rate of rare earth, uranium and thorium is improved, and the production of radioactive waste residue is reduced. According to the present invention, the comprehensive utilization of the radioactive waste residue is achieved, the amount of the radioactive waste residue is reduced, and the environmental pollution is avoided; during the mineral dressing process, the titanium-containing ilmenite and the monazite are separated, such that the problem that titanium enters the subsequent rare earth, uranium, thorium extraction process so as to easily cause the generation of the three-phase matter is avoided; and H2O2 is added during the preferred dissolving process of the hydrochloric acid, such that the recovery rate of the rare earth is easily increased, and the extraction separation pressure of the subsequent complete dissolving residue is reduced.

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 relates to a beneficiation method of high-mud micro-fine particle rare earth minerals. The beneficiation method includes the following steps that magnetic separation is carried out afterreselection to obtain magnetic separation concentrates and magnetic separation tailings; classification of the magnetic separation concentrates is carried out, wherein the magnetic separation concentrates in the +A size fraction are subjected to spiral chute reselection and shaker reselection to obtain shaker rare earth concentrates and shaker tailings, the magnetic separation concentrates in the-A size fraction is subjected to slurry adjusting, and one-time flotation roughing, one-time flotation sweeping and one-time blank selection are carried out to obtain flotation coarse concentrates; and the flotation coarse concentrates are subjected to reselection to obtain centrifugal reselection rare earth concentrates and centrifugal reselection rare earth middlings, and the shaker rare earthconcentrates and the centrifugal reselection rare earth concentrates are combined into total rare earth concentrates. By means of the beneficiation method, the processing capacity per unit area is high, the sorting efficiency is high, and the floor space is saved. The method combining flotation and reselection is adopted, the consumption of flotation reagents is small, the cost is low, the mineralseparation enrichment ratio is high, and the rare earth recovery rate is high.

The invention provides a method for extracting rare earth from rare earth-containing sludge. The method comprises the following steps: 1, allowing the rare earth-containing sludge to contact with an acidic aqueous solution in order to leach the rare earth-containing sludge, and separating to obtain a rare earth element-containing leachate; and 2, allowing the leachate to contact with an organic solvent containing an extraction agent, and extracting to obtain a raffinate water phase and a rare earth element-containing extraction organic phase, wherein the extraction agent is a phosphorus-to-oxygen double bond-containing phosphorus-containing extraction agent, carboxylic acid extraction agent and sulfur-to-oxygen double bond-containing sulfur-containing extraction agent mixture. The method allows rare earth to be leached and extracted from the rare earth-containing sludge in a high yield mode and rare earth chloride to be prepared, the recovered rare earth chloride can be used for producing catalysts, and the method has the advantages of simple whole process, environmental protection, low energy consumption, less production device investment and low operating cost.

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 belongs to the technical field of mineral processing, and relates to a calcium roasting floatation separation method for bastnaesite. The method comprises the following steps that firstly, bastnaesite and calcium hydroxide are mixed and roasted to obtain roasted ore; secondly, the roasted ore is placed in a floatation tank of a floatation machine, and water is added to form ore pulp; thirdly, water glass, oxalic acid or oxalate, sodium oleate and second oil are added in sequence and stirred, and roughing concentrate and roughing tailings are obtained through floatation; fourthly, the rouging tailings are scavenged in a five-nine level mode, and the calcium fluoride enrichment and the rare earth oxide are obtained. According to the method, the production procedure is shortened, meanwhile, consumption of reagent is reduced, resource utilization of valuable elements is achieved, the economic benefits are increased, and the environmental pollution is reduced.

The invention discloses a beneficiation method for recovering uranium from rare earth ore. The beneficiation method comprises the steps that uranium-containing rare earth ore is finely crushed and then classified, and coarse-fraction ore and fine-fraction ore are pre-enriched through a dense medium cyclone and a high-intensity magnetic separator correspondingly; after the mixed rough concentrate is reground, rare earth minerals are firstly subjected to flotation, uranium minerals are then subjected to flotation, and after flotation uranium concentrate is reground, the uranium grade is further improved through weak magnetic iron removal; and after scavenging tailings in the flotation process are reground, uranium ore is further separated and enriched through reselection, the uranium concentrate subjected to reselection is subjected to strong magnetic separation, the uranium grade is improved, the yield of the finally obtained uranium concentrate is 5.50%, the uranium grade is 0.27%, and the recovery rate is 71.44%. According to the beneficiation method for recovering the uranium from rare earth ore, precious uranium resources can be efficiently recovered while rare earth ore recovery is not affected, and the radioactive hazard to the environment is reduced.

The invention relates to a preparation method of crystalline rare-earth carbonate. According to the scheme, the method comprises the following steps: selecting ion absorpt deposit and carrying out an in-situ leaching method, wherein the in-situ leaching method comprises the following steps: preparing a mixed leaching agent with the mass fraction being 2% by using two ammonium salts which are in a mass ratio of (1-4) to 1, adding an aluminum inhibitor which is 0.05% of mass of the mixed leaching agent, stirring evenly, and then carrying out in-situ leaching according to a liquid-solid ratio of (0.1-2) to 1; after the leaching solution completely seeps, adding top wash ore which is 10% of mass of the leaching agent, collecting the leaching solution, clarifying, and adding a precipitator, wherein the mass ratio of the precipitator to the leaching solution is (0.1-0.5) to 1; fully stirring for over 30 minutes, and standing and ageing for 6-24hours; filtering, washing sediment twice with clear water, filtering again, and baking at 110 DEG C, so as to obtain the crystalline rare-earth carbonate, wherein the recovery rate is 70-85%, and the purity is 90-95%. The crystalline rare-earth carbonate is prepared from easily available raw materials and is low in cost, high in recovery rate and high in product purity.

The invention relates to a method for preparing rare earth oxide powder by oxidizing and roasting a rare earth mixture, which comprises the following steps of: roasting the rare earth mixture containing rare earth chloride, nitrate or sulfate in an air atmosphere to obtain the rare earth oxide powder, wherein the roasting in the air atmosphere is divided into a first-stage roasting and a second-stage roasting, the first-stage roasting is to roast the rare earth mixture at 250-400 DEG C to obtain a precursor, the second-stage roasting is to roast the precursor by heating to 600-1200 DEG C, the air humidity is greater than 60%, and the rare earth oxide powder is obtained; the tail gas generated in the second-stage roasting is absorbed to obtain an inorganic acid by-product rare earth mixture. The method has the advantages of being simple in process, environmentally friendly, good in product performance and the like, and has a good industrial application prospect.

The invention belongs to the field of recycling of resources, in particular to a method for waste rare earth luminescent material by dual hydrochloric acid. First hydrochloric acid was used to dissolve the red phosphor powder (Y₂O₃:Eu) priority, and yttrium-rich rare earth chloride solution and residue were obtained after filtered. Residue's major components were green and blue phosphor powder, and the removal of Ca²⁺ in filtrate was conducted by using Na₂SO₄, and CaSO₄ precipitation separation was conducted to get rich rare earth chloride solution, europium and yttrium. Residue was mixed with alkali to perform alkaline fusion at high temperature to decompose green and blue powder, then sodium aluminate, magnesium, barium and rare earth oxides were obtained. Alkaline fusion products were washed with water, and filtered, and then sodium aluminate solution and residues containing rare earth oxides were obtained.