10 results about "Oxalate precipitation" patented technology

The application provides a method for treating and recycling iron-containing waste sulfuric acid in titanium dioxide production, which is based on screening of a strain capable of treating iron-containing waste water in a low pH environment, and establishes a method for treating iron-containing waste sulfuric acid, which can effectively realize resource recycling. The waste water treatment bacteria used are Bacillus QD-QJ-062 strain, and the preservation number is CGMCC No.33725. The QD-QJ-062 strain of Bacillus screened by the application can effectively treat the iron-containing waste water in a low pH environment, promote the generation of ferrous oxalate precipitation, and generate ferrous oxalate by-products. The generated ferrous oxalate can be converted into ferrous sulfate by sulfuric acid, and oxalic acid can be recycled, thereby reducing the operation cost. The sulfuric acid solution after iron removal can be neutralized by limestone to generate high-purity gypsum, thereby realizing resource recycling and treatment.

The invention discloses a method for treating a waste lithium battery by using an ultrasonic-enhanced deep eutectic solvent. The method comprises the following steps: pretreating the waste lithium battery to obtain positive electrode material powder; mixing the hydrogen bond donor and the hydrogen bond acceptor to form a deep eutectic solvent; adding the positive electrode material powder into a deep eutectic solvent, and performing leaching reaction under the action of an ultrasonic external field to obtain filtrate and filter residues; adding a precipitator into the filtrate, and reacting under the ultrasonic-assisted action to obtain lithium carbonate, carbonate or oxalate precipitate and post-precipitation liquid; treating the precipitated liquid to obtain a purified deep eutectic solvent for recycling; and washing and drying the lithium carbonate, carbonate or oxalate precipitate to obtain a nickel-cobalt-manganese precursor and battery-grade lithium carbonate. According to the method, the mass transfer problem caused by high viscosity of the deep eutectic solvent is solved by means of the cavitation effect and the micro-jet effect through the ultrasonic external field strengthening technology, the high leaching rate of key metal is achieved, meanwhile, the reaction time is shortened, and the process economy and industrial feasibility are improved.

The invention provides a lithium battery positive electrode material and a regeneration method thereof, and belongs to the technical field of waste battery recycling. The method comprises the following steps: preparing a deep eutectic solvent formed by oxalic acid dihydrate and betaine hydrochloride and / or choline chloride; the method comprises the following steps: pretreating waste NCM positive electrode materials in different proportions, mixing the pretreated waste NCM positive electrode materials with a solvent to form a selective leaching system, and performing coordination precipitation reaction to realize high-selectivity leaching of lithium and oxalate precipitation of transition metal; and mixing and calcining the obtained precipitate and a lithium source, and directly regenerating to obtain the positive electrode material with a specific stoichiometric ratio. The method can efficiently treat the mixed waste materials in a short time, and is simple in technological process, high in metal recovery rate and environmentally friendly.

This application relates to the field of battery cathode materials, and in particular to a high-tap-density lithium-rich manganese-based cathode material and its preparation method. In this application, phosphate and oxalate are used as precipitants, and a certain amount of polymer resin is added. The polymer resin participates in the oxalate precipitation process, followed by sintering. Simultaneously, high-speed stirring and ultrasonic treatment are used to obtain a relatively dense particle system, which also improves the temperature tolerance of the processing. This method enables the achievement of high tap density and good electrical performance even with certain temperature fluctuations.

The application belongs to the technical field of scandium separation and purification, and particularly relates to a method for separating and purifying scandium from crude nickel-cobalt hydroxide, which comprises the following steps: using 0.1-0.5 mol / L dilute sulfuric acid to leach the crude nickel-cobalt hydroxide, and filtering to obtain a scandium-containing leaching solution, wherein the ratio of the dilute sulfuric acid to the crude nickel-cobalt hydroxide is (3-5) mL:1 g, and the molar ratio of sulfuric acid to scandium is (3-5):1; using an extractant comprising Cyanex572 and Aliquat336 to treat the scandium-containing leaching solution to obtain a scandium-containing organic phase; using an oxalic acid solution to back-extract the scandium-containing organic phase to obtain scandium oxalate precipitation; and calcining the scandium oxalate precipitation to obtain scandium oxide. The technical scheme adopts a selective leaching process to realize efficient separation of scandium from main metals nickel and cobalt at the front end, has low reagent consumption, a short process, and great cost advantages; a new type of synergistic extraction technology is adopted, which has super-high selectivity and extraction capacity for scandium, the prepared scandium oxide has a purity of greater than or equal to 96%, and the scandium recovery rate is greater than or equal to 89%.

This invention discloses a solid waste-based highly active carbon material and its preparation method. It uses industrial waste distiller's grains and spent lithium-ion battery cathode materials as raw materials. The distiller's grains are crushed into particles, while the cathode materials are separated by acid dissolution and oxalate precipitation to obtain a lithium-ion solution and a transition metal oxalate precipitate. Cerium metal salt is added to the precipitate to obtain a non-lithium multi-metal precursor. The resulting distiller's grain particles and multi-metal precursor are then mixed and activated to modify the carbon material with transition metals. Finally, the carbon material is impregnated in the obtained lithium-ion solution and calcined at high temperature to obtain the final solid waste-based highly active carbon material. This invention uses solid waste as raw material and can fully utilize the various active metal components in spent lithium-ion batteries. The resulting solid waste-based highly active carbon material has good capture efficiency for organic molecules in high-temperature exhaust gases, thus possessing promising prospects for large-scale industrial preparation and application.

The invention relates to a device and method for promoting continuous operation of oxalate precipitation through ultrasonic assistance, the device comprises a reactor and a mixer, a stock solution pump and a precipitant pump are respectively connected with the top and the left end of the mixer through pipelines, the mixer is connected with an inlet of the reactor, an outlet of the reactor is connected with an alternate filter, and the alternate filter is connected with a mother liquor storage tank; a nitrate solution and an oxalic acid solution are respectively sent into a mixer for mixing through a stock solution pump and a precipitant pump, and then sent into a reactor for precipitation reaction, slurry is transferred into a filter, and solid-liquid separation is realized through vacuum filtration. The ultrasonic technology is applied to the continuous flow tubular reaction device, formation of oxalate is promoted through the ultrasonic enhancement technology, the reaction liquid mixing effect is further improved, the reaction time is shortened, slurry obtained after reaction is directly filtered, aging time is not needed, and continuous operation of the device is achieved. Meanwhile, the ultrasonic enhancement technology can effectively prevent the pipeline from being blocked, long-term stable operation of the device is achieved, and automatic operation is completed.

The application provides a high-efficiency green high-purity hafnium oxide preparation method, which comprises the following steps: melting hafnium oxide raw materials, solid alkali and fluxing agent to obtain alkali melting clinker; adding the alkali melting clinker into deionized water to perform leaching and filtration to obtain hafnium hydroxide precipitation; adding the hafnium hydroxide precipitation into concentrated sulfuric acid to obtain hafnium sulfate solution; adding a composite chelating agent into the hafnium sulfate solution to remove the precipitation to obtain low-zirconium hafnium sulfate solution; adding activated carbon into the low-zirconium hafnium sulfate solution to filter to obtain hafnium sulfate solution; evaporating and concentrating the hafnium sulfate solution and crystallizing to obtain hafnium sulfate crystal; adding the hafnium sulfate crystal into concentrated hydrochloric acid and refluxing, evaporating and cooling and crystallizing to obtain hafnium oxychloride crystal; dissolving the hafnium oxychloride crystal in water and adding oxalic acid to generate hafnium oxalate precipitation; and calcining the hafnium oxalate precipitation. The hafnium oxide obtained by the method has a purity of 99.995% or more and the zirconium impurity is reduced to 5 ppm or less.

The invention relates to the technical field of rare earth oxalate recovery, and discloses a rare earth oxalate precipitation device, which is used for mixing oxalic acid and rare earth ions and then collecting, and comprises a precipitation box, and a rotating assembly used for stirring the mixture and scraping precipitates attached to the surface of the inner cavity of the precipitation box is arranged in the middle of the inner cavity of the precipitation box. A discharging assembly used for discharging waste water is arranged at the bottom of an inner cavity of the settling tank and comprises a fixing block, the fixing block is fixedly connected to the bottom of the inner cavity of the settling tank, and a feeding assembly used for automatically putting oxalic acid and rare earth ions into the settling tank is arranged at the top of the inner cavity of the settling tank. The connecting rod rotates to drive the rotating shell to rotate and slide up and down at the same time, so that the stirring rod slides up and down while revolving with the connecting rod as the circle center, it is ensured that rare earth oxalate in the settling tank is uniformly stirred, and the multi-dimensional stirring mode is beneficial to breaking of the agglomeration and layering phenomena between materials; and the stirring uniformity and efficiency are improved.

The present application relates to a kind of based on organic sulfonic acid scandium double salt precipitation scandium recovery method, comprising: using sulfuric acid to the scandium concentrate is treated by acid immersion to obtain the scandium-containing leaching solution;Scandium-containing leaching solution is adjusted to alkaline pH, and precipitate to obtain coarse scandium hydroxide;Coarse scandium hydroxide is reacted with organic sulfonic acid to obtain organic sulfonic acid scandium salt;Organic sulfonic acid scandium salt is mixed with saturated sulfate solution and carries out double salt precipitation, and separation is obtained containing scandium double salt;Scandium double salt is washed, precipitated by ammonia, acid dissolution, oxalate precipitation and high temperature calcination, and high-purity scandium oxide is obtained.The present application combines organic sulfonic acid scandium salt and sulfate for the first time to construct a new double salt precipitation system, which can realize efficient and high-selectivity separation of scandium, various rare earth elements and conventional metal impurities in a single precipitation, and obtain scandium oxide with purity higher than 99.9%.The total recovery rate of scandium is more than 85%.The process is simple, without complex saponification process, reducing the generation of salt-containing and ammonia-containing wastewater, and reducing equipment investment and operating cost.