20 results about "Maghemite" patented technology

The invention relates to the technical field of mineralogy, in particular to a complex iron mineral distinguishing and quantifying method and an iron mineral content analysis method, which innovatively combines chemical dissolution, automatic mineralogy analysis and a micro-area magnetic verification technology to realize distinguishing and quantifying of complex iron minerals. According to the analysis method, a closed and mutual verification analysis system is formed, acid treatment of carbonate, automatic mineralogy analysis of residual minerals, micro-area magnetic verification correction of misjudgment of maghemite, element surface scanning verification of mineralogy total quantification accuracy and a final calculation result, and closed verification of the total iron content of chemical analysis are combined, and therefore the comprehensive performance of the magnetic separation system is improved. The reliability of a final result is ensured and standardized popularization and application are facilitated.

The present disclosure relates to an α-Fe-containing rare earth-iron-based magnetic powder including: a core region containing a rare earth R and Fe, where R represents at least one selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sm; an α-Fe-containing region located outside the core region and containing α-Fe and at least one selected from the group consisting of oxides, nitrides, and oxynitrides of the rare earth R; and an iron oxide-containing region located outside the α-Fe-containing region and containing magnetite or maghemite.

The present application relates to the technical field of mineralogy, and particularly provides a complex iron mineral distinguishing and quantifying method and an iron mineral content analysis method, which combines chemical dissolution, automatic mineralogy analysis and micro-area magnetic verification technology for the first time to realize the distinguishing and quantifying of complex iron minerals. The analysis method constitutes a closed and mutually checked analysis system, which combines acid treatment of carbonates, automatic mineralogy analysis of residual minerals, micro-area magnetic verification to correct the misjudgment of magnetic hematite, element surface scanning to check the accuracy of overall mineralogy quantification, and final calculation results, and checks the total iron content of chemical analysis to ensure the reliability of the final results and facilitate the standardized popularization and application.

This invention relates to a process for treating acidic mine wastewater (AMD). The process includes the following steps: adjusting the pH of the AMD to a range of 3 to 5; adding magnetite nanoparticles to form a slurry; and a) aerating the slurry obtained in step 3), or b) simultaneously heating and mixing the slurry obtained in step 3). The magnetite nanoparticles loaded with one or more metals and sulfate ions and precipitated metals are then separated from the slurry.

The present invention discloses a variable grinding process for magnetite and hematite, belonging to the technical field of iron ore beneficiation. The present invention adopts a closed-circuit grinding overflow control classification operation, so that the fineness of the overflow product after the first grinding and classification operation meets the requirements of the separation conditions. The closed-circuit grinding overflow control classification operation equipment consists of a ball mill, a spiral classifier, and a hydrocyclone. The hydrocyclone is controlled and classified through the overflow of the grinding classification, which reduces the number of mills and simplifies the configuration, avoiding the problems of large classification area and low classification accuracy of the traditional control classification using a spiral classifier; through the variable process, the needs of separate magnetite production, separate hematite production and mixed production of magnetic hematite are realized to obtain corresponding iron concentrate products, thereby improving the adaptability of the grinding process of the main grinding equipment under the changes in the properties of different batches of raw ore, achieving flexible production, fully utilizing the production capacity of the process equipment, and improving efficiency.

The present application relates to the field of denitration catalyst, disclose a kind of low-temperature denitration catalyst and its preparation method and application.The low-temperature denitration catalyst of the present application contains the product of magnetite and spinel manganese oxide compound, the magnetite is gamma-Fe2O3, and the spinel manganese oxide is lambda-MnO2.The low-temperature denitration catalyst of the present application is not contained V, and N2 selectivity is high, and the denitration performance is good.

The invention relates to the technical field of waste treatment, in particular to a stabilization treatment method for iron-arsenic waste residues. The method comprises the following steps: mixing iron-arsenic waste residues or pretreatment residue liquid of the iron-arsenic waste residues with a bicarbonate solution to obtain a turbid liquid; and adjusting the pH value of the turbid liquid to 4-9, and then carrying out normal-pressure and constant-temperature culture. According to the method, the amorphous iron-arsenic waste residues are subjected to normal-pressure and constant-temperature culture, so that the amorphous iron-arsenic waste residues are converted into stable minerals (hematite and maghemite), and the stability and magnetic separability of the iron-arsenic waste residues are improved. In the process of converting the amorphous iron-arsenic waste residues into the stable-state minerals, the arsenic which originally exists mainly in an adsorption form enters a crystal structure of the minerals, so that the stability of the arsenic in the iron-arsenic waste residues is improved, and secondary pollution caused by the arsenic is avoided.

The invention relates to the technical field of magnetic flotation columns, and discloses pneumatic magnetic flotation column equipment which comprises a magnet exciting coil fixedly connected to the periphery of an inner cylinder. An outer cylinder is arranged on the periphery of the excitation coil; the bottom of the inner cylinder is fixedly connected with a conical concentrator; a feeder is arranged at the middle-upper part of the inner cylinder; an air hole is formed in the equipment, and the other end of the air hole is connected with an air source for generating air bubbles in the equipment; and the pulsation air-entrapping device is arranged outside the outer cylinder and used for providing an air source, and the pulsation control device controls the airflow of the air source, so that the bubble generating device forms pulsation bubbles in the equipment, and the height of the ore pulp liquid level generates pulsation change. The problem that the flotation operation is affected due to the fact that a flotation reagent is diluted through flushing water is solved, the problem that the index of metal ores with large density such as maghemite, pyrrhotite and titanomagnetite is low is also solved, meanwhile, the problems of'ore pulp running out of a groove 'and'black ore running out of the groove' are solved, the one-machine multi-section flotation technology is achieved, and the product recovery rate is increased.

The present invention relates to the technical field of mineral processing, and particularly to a continuous grinding, magnetic - flotation short - process classification and separation process for mixed iron ore. 1) The mixed iron ore mainly composed of magnetite and hematite is crushed to 0 - 12 mm and fed into the first - stage ball mill as raw ore; 2) The first - stage overflow product is fed into the second - stage ball mill; 3) The secondary overflow product is subjected to N - stage weak magnetic separation to obtain high - grade magnetite concentrate with a grade of 68% - 69%; 4) The first - stage weak magnetic tailing product is fed into a high - intensity magnetic separator for separation. After the second - to N - stage weak magnetic tailings are mixed with the high - intensity magnetic concentrate, they are all fed into the reverse flotation operation for separation, and the high - intensity magnetic tailings are discarded as part of the comprehensive tailings; 5) The obtained flotation concentrate and the weak magnetic separation concentrate are combined into comprehensive concentrate. The present invention has strong adaptability to changes in ore properties, significantly improves the recovery rate and grade of iron in iron concentrate, reduces production costs, and is of great significance for the efficient recovery of high - magnetic mixed iron ore.

The invention relates to the field of magnetic simulation, in particular to a magnetic simulation method for simulating a low-temperature oxidized geological sample, which comprises the following steps: S1, constructing a double-layer model in Cubit software; s2, setting interface exchange interaction constants corresponding to three exchange types including no exchange, weak exchange and uniform exchange for the double-layer structure; s3, hysteresis parameters under the three exchange interaction constants are calculated, and the numerical calculation result of which exchange constant is closer to the experimental result / literature result is judged; s4, constructing a complex multi-layer low-temperature oxidation model in Cubit software; s5, constructing a low-temperature oxidation process model based on the theoretical oxidation kinetics model and simulating particles with various particle sizes; s6, comparing a simulation result with a hysteresis parameter measured by an experiment; and S7, drawing a multi-particle-size micro-magnetic structure chart and a multi-particle-size hysteresis loop. According to the method, the oxidation process is refined, a double-layer core-shell structure of magnetite and maghemite can be constructed, and a particle aggregation model is established.

The invention discloses a high-entropy ferrite wave-absorbing ceramic material and a preparation method thereof, and relates to the technical field of ceramic wave-absorbing materials, the chemical formula of the material is (Fe0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2) Fe2O4, the crystal structure is a single spinel structure or a spinel and maghemite two-phase structure, the minimum reflection loss value is-16 dB to-77 dB, the effective absorption bandwidth is 4.4 GHz to 6.7 GHz, and the wave-absorbing material has a good wave-absorbing effect. The preparation method comprises the following steps: firstly, dissolving and stirring specific metal salt to obtain a uniform solution, adding a NaOH solution, mixing, filling into a reaction kettle, carrying out hydrothermal reaction at 140 DEG C for 5 hours, heating a precursor to 400-1000 DEG C at a speed of 5 DEG C / min in an argon atmosphere, and calcining for 2 hours; the material is simple to prepare, high in absorption performance and wide in frequency band, can be used in the field of electromagnetic wave absorption, and solves the problem of insufficient performance of existing wave-absorbing materials.

To provide magnetic powder having excellent responsiveness to a magnetic field, and to provide a method for producing the same.SOLUTION: An α - Fe-containing rare earth-iron-based magnetic powder including a core region containing a rare earth R (R is at least one selected from the group consisting of Y, La, Ce, Pr, Nd, Pm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Sm) and Fe, an α - Fe-containing region containing α - Fe and at least one selected from the group consisting of an oxide, a nitride, and an oxynitride of the rare earth R outside the core region, and an iron oxide-containing region containing magnetite or maghemite outside the α - Fe-containing region.SELECTED DRAWING: Figure 1

The invention relates to a high-entropy multi-principal-element magnesite oxide infrared emission material. The chemical formula of the material is (MgA1A2A3A4Ti) 2O3, a magnesium titanium ore structure is formed, A1, A2, A3 and A4 are any four metal ions of Co, Ni, Cr, Cu, Fe, Mn, Sr and Ca, the molar percentage of Mg < 2 + > and Ti < 4 + > is 15-35%, and A1, A2, A3 and A4 meet the atomic equimolar ratio; the magnesium titanium ore belongs to a trigonal system, O < 2-> ions form hexagonal closest packing, and octahedral gaps formed by hexagonal packing of oxygen ions are alternately filled with Mg < 2 + > and Ti < 4 + > ions. Meanwhile, the invention also discloses a preparation method of the material. The method is easy to operate and high in production efficiency, the obtained material has good high-temperature stability and infrared radiation capacity, the emissivity of the material is effectively improved by 0.78-16 microns, and the method is suitable for extreme scenes such as building energy saving and aerospace thermal control.

The invention discloses an iron ore beneficiation fine grinding and screening experimental device and a construction method thereof, and relates to the field of magnetite screening. The device comprises a screening box, a screening assembly is arranged in the screening box, a driving assembly is arranged in the screening box, the driving assembly is matched with the screening assembly, and a grinding box is arranged at the top of the screening box. Magnehemite is ground through the grinding assembly in the grinding box, ground maghemite powder enters the screening box through the communicating pipe, graded screening is conducted through the screening assembly, and the screened large-particle maghemite powder and medium-particle maghemite powder enter the material receiving box through the through groove; the large-particle maghemite powder and the medium-particle maghemite powder in the material receiving box enter the feeding box through the conveying pipe, and the large-particle maghemite powder and the medium-particle maghemite powder are fed into the grinding box again through the feeding assembly and the connecting pipe for secondary grinding, so that the material transfer time is shortened, and the machining efficiency is improved; and the working intensity of workers is reduced.

The invention relates to the technical field of mineral magnetic flotation equipment, and discloses magnetic flotation column equipment with a pulsating elastic cavity. A magnet exciting coil is fixedly connected to the periphery of the inner cylinder; an outer cylinder is arranged on the periphery of the magnet exciting coil; the bottom of the inner cylinder is fixedly connected with a conical concentrator; a first elastic cavity is coaxially and fixedly formed in the axis position of the inner cylinder; and the second elastic cavity is arranged on the inner side wall of the equipment. The problem that a common elutriation magnetic separator or a magnetic separation column depends on washing water is solved, and the problem that when the elutriation magnetic separator is used for concentrating maghemite, pyrrhotite, titanomagnetite and other occasions, due to the fact that iron ore concentrate and harmful mineral particles are different in magnetism and density, the density difference is not large, and the magnetic separation effect is poor is solved. And in the application process, a flotation process does not need to be additionally added to remove the impurities any more.

This invention provides a method for continuously manufacturing electric wire conductors in which the surface is insulated by an aggregate of stacked Maghemite microparticles that are magnetically attracted to each other by saturated magnetization. [Solution] The method involves creating a suspension in which maghemite microparticles are dispersed in an organic compound and the viscosity can be changed, continuously adsorbing the suspension onto a conductor, continuously covering the surface of the conductor with an aggregate of maghemite microparticles using the suspension, continuously saturating the magnetization of the maghemite microparticles, continuously winding up the conductor of the wire insulated with the aggregate of maghemite microparticles, creating a suspension in which an aggregate of fine crystals of an organic iron compound that precipitates ferrous oxide by thermal decomposition is dispersed in an organic compound with a high boiling point, thermally decomposing the organic iron compound, oxidizing the ferrous oxide to ferric oxide, reducing the viscosity of the suspension with an organic solvent, continuously immersing the conductor in the low-viscosity suspension, continuously vaporizing the organic solvent and organic compound from the conductor, continuously passing the conductor through a magnetic field, and continuously winding the conductor onto a bobbin.

A process for converting a hematite-containing material to a maghemite-containing material is developed. The process comprises: producing a crushed hematite-containing material by crushing the hematite-containing material utilizing a means for grinding, obtaining a hematite-containing material with a particle size in a range of 150 µm to 500 µm by sieving the crushed hematite- containing material utilizing a means for sifting, and exposing the hematite-containing material with the particle size of 150 µm to 500 µm to a microwave energy with a frequency in a range of 890 MHz to 930 MHz for an exposing time in a range of 30 seconds to 360 seconds utilizing a means for radiating a microwave beam. An exposed thickness of the hematite-containing material with the particle size of 150 µm to 500 is a range of 3 cm to 10 cm that has a particular effect on phase changing of the hematite to the maghemite.

The application discloses a hydrogen production and suspension magnetization roasting coupling device and method, which comprises a hydrogen production device, a suspension magnetization roasting device and a coupling connection assembly. The device generates reducing gas with carbon monoxide and hydrogen as effective components through oxidation reaction under pressurized non-catalytic conditions, so that hematite, limonite and siderite are converted into magnetite or maghemite which is strongly magnetic under the condition of reducing agent atmosphere, and then high-grade and high-recovery iron concentrate is obtained through magnetic separation, thereby realizing efficient utilization of resources. The process flow is short, load increase and decrease is convenient, operation flexibility is large, the hydrogen production system and the hydrogen-based mineral phase conversion system are highly fused and coupled, raw materials are wide, gas production is low in cost, low-carbon environmental protection, heat energy recycling rate is high, and the application scope is wide, and the like, thereby providing a new way for effective development and utilization of refractory ore resources.

This invention discloses a system, technology, and material composition for correcting eye condition. The system includes a processing device and an etching device. The processing device includes a pattern correction module configured to provide a selected two-dimensional pattern based on visually non-permanent input data instructing a user, and configured to generate operating instructions to form the selected two-dimensional pattern on the surface of the cornea via the etching device. The etching device is configured to etch the selected pattern onto the surface of a user's cornea. The material composition includes an aqueous solution containing a plurality of nanoparticles, the nanoparticles comprising magnetite nanoparticles encapsulated by biocompatible protein chains. The material composition can be used as eye drops, thereby allowing the nanoparticles to occupy the etched area on the cornea, thus maintaining the correction of eye condition.

A method of preparing particles is disclosed which comprises preparing seed particles; providing one or more reactants to a mixture comprising the seed particles; and reacting the one or more reactants with the seed particles to provide the particles, wherein, the particles have a diameter greater than that of the seed particles, and the particles have a diameter of greater than 200 nm. The particles may comprise iron oxides such as magnetite or maghemite. The seed particles may comprise the same material as the particles. The seed particles may comprise a core-shell material with an iron oxide core and a silica shell. The particles may comprise a diameter less than 400 nm. Also disclosed is a composition of particles dispersed in a biofluid.