1776 results about "Magnetite" patented technology

A magnetic recording medium having a nonmagnetic substrate, and a soft magnetic layer and a ferromagnetic layer having a thickness of 5 to 150 nm formed in this order on the nonmagnetic substrate, in which, the ferromagnetic layer contains a spherical, ellipsoidal or plate-form ferromagnetic powder and a binder, and has an axis of easy magnetization substantially in a perpendicular direction, and the soft magnetic layer contains a spherical or ellipsoidal magnetite soft magnetic powder having a particle size of 30 nm or less, a rate of variation in particle size of 20% or less and a saturation magnetization of 10 to 60 Am²/kg, and a binder.

The invention discloses a preselecting method of low-grade magnetic iron ore, comprising the steps of crushing the raw ore of the magnetic iron ore by coarse crushing, intermediate crushing and fine crushing operations, conveying to subject to ultra-fine crushing operation, and then crushing by a high-pressure roller mill, scattering the crushed product by a wet cylindrical sieve, conveying the ore on the cylindrical sieve to the vibrating sieve by a belt to perform wet gradation, conveying the ore on the vibrating sieve to a dry magnetic separator by the belt to discard the waste, returning the ore concentrate of the dry magnetic separator to the high-pressure roller mill to crush the ore concentrate again, perform magnetic separation and discarding tailings of the ore concentrate below the vibrating sieve and the ore concentrate below the cylindrical sieve in a wet coarse grain intermediate-field intensity magnetic separator, and selecting the coarse ore concentrate of the intermediate-field intensity magnetic separator by a grinding separation technology. The invention has the advantages that the invention selects quantities of qualified mine tailings by wet magnetic separation before grinding ore, reduces ore grinding work, reduces ore grinding energy consumption and has high system processing capacity; the invention can be widely used in magnetic ore dressing plant, and in particular suitable for treatment of preselecting low-grade magnetic iron ore with the iron grade lower than or equal to 22%.

The present invention relates to a poly(organophosphazene)-superparamagnetic nanoparticle complex including a biodegradable and thermosensitive poly(organophosphazene) and a iron oxide (Fe₃O₄, Magnetite)-series ferrite superparamagnetic nanoparticle, a preparation method, and uses of carrying a physiologically-active material, a bio-material and a biomaterial for cancer hyperthermia. The iron oxide is used as a MRI contrast agent for T-₂ and T₂* weighted image, and the poly(organophosphazene) shows a sol-to-gel behavior depending upon the temperature change. The complex is a bound-type where the superparamagnetic ferrite nanoparticle is bonded to phosphazene-based polymer via hydrophobic binding, and a mixed-type where the superparamagnetic ferrite nanoparticle is physically mixed with the phosphazene-based polymer.

The invention discloses a method for concentrating extremely low-grade refractory magnetite to achieve higher-grade iron ore concentrate. The process proposal comprises the following steps of: dry type magnetic separation and tailing rejecting, stage grinding, wet type magnetic separation, magnetic concentrate fine screening classification, minus sieve magnetic separation, plus sieve regrinding and recleaning and concentrate extraction directly through magnetic separation of an electromagnetic wreathed column. Namely, on the basis of conducting stage grinding separation on crude ore, electromagnetic concentration, fine screening and plus sieve regrinding and recleaning are implemented to improve the final iron ore concentrate grade. With the method adopted, the production cost is reduced,the concentrate grade is raised up to 71.96 percent, the tailings grade is decreased to 4.50 percent and the secondary pollution to the environment is also avoided.

The technological process of separating and extracting metal elements from V-Ti iron ore includes the steps of: agglomerating ore powder of mixing V-Ti iron ore powder, reductant, additives and adhesive, pressing the mixture into 10-25 mm diameter agglomerates and drying at 80-90 deg.c; reducing inside one bottom rotating furnace to obtain metal products; smelting the metal products in an electric furnace to obtain molten iron and V-Ti slag component, and smelting the V-Ti slag component to obtain V-Cr oxide and Ti slag as the material for producing titanium while. The present invention has high reduction temperature, fast reduction speed, short reduction time, high production efficiency, high metal and V-Ti recovering rate and less environmental pollution.

The invention discloses a blast-furnace smelting method for vanadium titano-magnetite. The method is realized in a way that: vanadium titano-magnetite accounts for 30-60% of ferrous burden which is fed into a blast furnace, and the burden comprises 40-65% of agglomerate, 30-50% of pellet and 5-10% of lump ore; the diacidic basicities CaO/SiO2 of agglomerate, pellet and blast-furnace slag are respectively controlled at 1.6-2.5, 0.6-1.0 and 1.05-1.20; the content of MgO in blast-furnace slag is controlled at 7.5-9.0%; by adding two batches of ore and three batches of coke and using the charging operation of the development center, manganese oxide ore or sintered manganese ore powder, and fluorite are incorporated into injection coal and injected into the blast furnace along with the coal powder; and thus, the content of MnO in the slag and the content of CaF2 in the slag are respectively controlled at 1.0-4.5% and 0.50-2.0%, and the oxygen-enrichment percentage of the blast furnace is controlled at 2.0-4.0%. Compared with the smelting blast furnace using the same quality and structure of the burden, the comprehensive coke ratio of the invention is reduced by 20-50kg per ton of iron, the content of TFe in the slag is reduced by 50%, and the comprehensive cost per ton of iron is reduced by 30-50 yuan. The invention has wide prospects for popularization and application.

The invention discloses a beneficiating method for ilmenite, relating to a method for preparing titanium concentrate and iron concentrate by beneficiating crude ilmenite. The method is characterized in that: a beneficiating process of the method orderly comprises the following steps of: (1) grinding the crude ilmenite; (2) performing alkaline leaching pretreatment under the conditions of heating, oxygenating and pressurizing; (3) filtering pulp which is subjected to the alkaline leaching pretreatment; (4) washing filter residue and grinding; and (5) performing magnetic separation to obtain the titanium concentrate and the iron concentrate. In the method provided by the invention, the characteristic of iron and titanium compact symbiosis and the isomorphism occurrence characteristic of vanadium are damaged from the source of vanadium titano-magnetite by adopting the pretreatment process, so that mineral transformation of the vanadium titano-magnetite is realized, dissociation on lattice layers of titanium and iron is realized, high-quality iron concentrate and titanium concentrate with lower iron content are obtained through grinding and the magnetic separation process, an alkaline medium used in the pretreatment can be recycled, and the process has a small influence on environment and a bright application prospect.

The invention belongs to the wet-process metallurgical filed and in particular relates to a method for preparing titanium solution by wet-processing on vanadium-titanium magnetite concentrates. The method for preparing titanium solution by wet-processing on vanadium-titanium magnetite concentrates comprises the following steps of: (1), mixing the vanadium-titanium magnetite concentrate with hydrochloric acid, and leaching to obtain an intermediate sizing agent; (2), filtering the intermediate sizing agent to obtain leaching liquor and leaching residues; (3), carrying out water-washing on the leaching slag to obtain washing water and washing slag; (4), carrying out fused-salt reaction on the washing slag to obtain fused-salt reaction materials; (5), carrying out water-washing and filtering on the fused-salt reaction materials to obtain water-washing materials; (6), carrying out acid pickling on the water-washing materials to obtain sizing agent, and filtering to obtain the acid-pickled sizing agent; (7), carrying out acid dissolving on the acid-pickled materials by using a sulfuric acid solution to obtain acid-dissolved materials; and (8), adding the acid-dissolved materials to the sulfuric acid solution for extracting, and filtering to obtain extracting solution which is the titanium solution. According to the method for preparing titanium solution by wet-processing on vanadium-titanium magnetite concentrates disclosed by the invention, the titanium in the iron concentrate is sufficiently utilized, so that the titanium resource utilization rate is high and the recovery rate of the titanium in the titanium concrete is higher than 90%.

An electromagnetic wave absorber comprising (a) soft ferrite having its surface treated with a silane compound having no functional group, (c) magnetite and (d) silicone, or comprising (a) soft ferrite having its surface treated with a silane compound having no functional group, (b) flat, soft magnetic metal powder, (c) magnetite and (d) silicone, which electromagnetic wave absorber excels in electromagnetic wave absorption, heat conduction and flame resistance, exhibiting less temperature dependence, and which electromagnetic wave absorber is soft, excelling in adhesion strength and further excelling in high resistance high insulation properties and in energy conversion efficiency being stable in MHz to 10 GHz broadband frequency. There is further provided a laminated electromagnetic wave absorber comprising the above electromagnetic wave absorber overlaid with a reflection layer of conductor, which laminated electromagnetic wave absorber can be closely stuck onto an unwanted electromagnetic wave emission source such as a high-speed operating device, having such an adhesive strength that even when stuck to a horizontal glassy-surface ceiling face of resin-made cage, would not fall.

The invention discloses a high-pressure roller milling-preselection processing method for vanadic titanomagnetite. The raw ore is subjected to coarse crushing, secondary crushing, fine crushing and high-pressure roller milling superfine crushing, an open circuit crushing, scrap circulation crushing or fully-closed circuit crushing method is adopted, and low-intensity magnetism and high-intensity magnetism preselection is performed. The method disclosed by the invention reduces the energy consumption of crushing and ore milling and improves the ore selection efficiency in comparison with the conventional process; and the low-intensity magnetism and high-intensity magnetism preselection can separately select the main target ores-titanomagnetite and ilmenite in the vanadic titanomagnetite with higher pertinence, and the ore selection flow is simpler. By adopting a high-pressure roller mill as the superfine crushing apparatus after fine crushing, the particle size of the final crushed product can be reduced, and meanwhile, the preselection tailing discarding before milling is realized, the milling grade is improved and the energy consumption of ore milling is reduced. Compared with the traditional process, the particle size of the product is small, the equipment operation rate is high, and the unit crushing energy consumption is low. Meanwhile, the superfine crushed product can besubjected to preselection tailing discarding so as to improve the milling grade, reduce the energy consumption of ore milling, lighten the burden on subsequent selection process and improve the production efficiency.

One aspect of the invention concerns a method of dewatering an aqueous magnetite slurry concentrate. In the method, the concentrate (78) is deposited on an external surface of a rotating drum (16) in which is located a stationary, permanent magnet (32) so that magnetite in the concentrate is attracted onto the surface of the drum by the magnet. The intensity of the magnet is sufficient to cause the magnetite to form on the drum surface a compacted cake from which water is displaced. The cake is then removed from the drum surface after it has passed the magnet. Other aspects of the invention concern the apparatus used in the method as well as the combination of the dewatering method and apparatus with a method and apparatus for concentrating an initial magnetite slurry feed.

The invention discloses a method for separating vanadium-titanium magnetite to extract iron, vanadium and titanium, comprising the following steps of: magnetically selecting raw magnetite, that is, acquiring iron-vanadium concentrate and tail magnetite after performing magnetic selection on the vanadium-titanium magnetite; sorting titanium concentrate from the tail magnetite, that is, acquiring the titanium concentrate after performing floating selection on the obtained tail magnetite; roasting and magnetically selecting the titanium concentrate, that is, performing enriched-titanium impurity-removing magnetic selection after roasting the titanium concentrate; finely selecting the iron-vanadium concentrate, that is, performing the magnetic selection and fine section again on the iron-vanadium concentrate obtained from magnetic selection; reducing and smelting, that is, mixing the titanium concentrate obtained from the impurity-removing process with the iron concentrate according to the beneficiation yield, adding in a reducer and soda ash to perform reduced iron and vanadium smelting process; purifying vanadium slag, that is, removing the impurity of the vanadium slag obtained by reducing and smelting by using the acidic dipping to obtain the high-quality titanium slag product with the content of TiO2 larger than 92%; and extracting vanadium from pig iron, that is, performing vanadium extraction by converter blowing on the vanadium-containing pig iron obtained by reducing and smelting to obtain the semi-steel and vanadium slag. The method not only improves the utilization ratio of titanium, iron and vanadium but also obtains the high-titanium slag product with the content of TiO2 larger than 92% so as to widen the application field of titanium.

The invention relates to the technical field of black metal ore exploitation and beneficiation, in particular to a beneficiation process of low-grade magnetite and specularite mixed ore, which is especially suitable for associated magnetite and specularite mixed ore of Zhouyoufang iron ore. The novel beneficiation process is realized according to an operation procedure and the process proceduressuch as ore crushing, one-stage grinding and grading, reselecting, one-stage weak magnetic separation, one-stage strong magnetic separation, two-stage grinding and grading (crude concentrate re-grinding), two-stage weak magnetic separation, two-stage strong magnetic separation, reverse floating and the like. The iron ore is comprehensively recycled, and a high-quality iron concentrate product is produced. The process has the characteristics of energy saving, high beneficiation efficiency and low beneficiation cost.

The invention relates to a method for comprehensive utilization of vanadium-titanium magnetite, which belongs to the field of new technology of direct reduction ironmaking in the metallurgical industry. In order to solve the problems of low utilization of iron, vanadium and titanium in vanadium-titanium magnetite, at the same time, due to the sintering process of traditional technology, the comprehensive energy consumption of the overall smelting process is relatively high, and the environmental pollution is serious. The invention provides a method of agglomerating vanadium-titanium magnetite and producing high-titanium slag and pearl iron by high-temperature reduction and melting in a rotary hearth furnace. The technical solution includes pelletizing of vanadium-titanium magnetite, high-temperature reduction in rotary hearth furnace, magnetic separation, and high-temperature reduction in rotary hearth furnace to directly produce high-titanium slag and pearl iron. Applying this method to process vanadium-titanium magnetite can not only effectively solve the problem of recovery of titanium and vanadium resources, but also obtain qualified iron pearls for steelmaking in electric furnaces, making full use of the iron, vanadium, and Valuable elements such as titanium.

The invention discloses a dry-grinding and dry-separation method of magnetite, which comprises the following steps of: feeding the crude ore of magnetite into a crusher for coarse crushing, and then feeding the crushed magnetite into a vibrating sieve for sieving; controlling the sieve meshes within a range of 35-75 mm; feeding the oversize product to the crusher for intermediate crushing and then feeding the crushed oversize product into a high-pressure roller mill along with the undersize product for fine crushing; breaking and grading the fine-crushed ore by a breaking-grading machine, thereby obtaining the products of three grain grades, i.e. coarse grains, fine grains and fine powder; returning the coarse-grain grade product to the high-pressure roller mill through an elevator, and feeding the fine-grain grade product to a dry type magnetic separator for magnetic separation and discarding tailings, wherein the magnetic field intensity is controlled within a range of 1200-3000 Gs; directly dryly stacking the discarded fine-grain grade tailings, and returning the fine-grain grade concentrate to the high-pressure roller mill through a belt conveyor and the elevator to form a closed loop; and feeding the fine-powder grade product into a cyclone magnetic separator, wherein the magnetic field intensity is controlled within a range of 600-1200 Gs, thereby obtaining concentrate or semi-concentrate. The dry-grinding and dry-separation method is low in power consumption, steel consumption and water consumption, and the tailings are easy to be disposed of.

The invention belongs to the technical field of efficient development of ultralow-grade ore resources and comprehensive utilization of associated minerals, and in particular relates to a combined beneficiation method and a combined beneficiation system for comprehensive recovery of associated iron-phosphate minerals. The combined beneficiation method for the comprehensive recovery of the associated iron-phosphate minerals comprises the following steps: sequentially performing three-section and two-closed-loop crushing and screening flow on raw ores, and performing dry separation to obtain fine ores; performing two-section closed-loop ore-grinding flow on the fine ores, performing fine magnetic separation for three times, and concentrating by using a wash mill to separate iron ore concentrate and discharge tailings; performing one-time roughing, one-time scavenging and three-time concentrating on the tailings at the temperature of 10-15 DEG C to obtain phosphate ore concentrate by floatation. Compared with the prior art, the invention provides a comprehensive recovery scheme for magnetic iron ore resources and phosphate ore resources in ultralow-grade associated iron-phosphate minerals. According to the scheme, the separation cost is low, the efficiency is high, energy is saved, the space occupation is low, and the comprehensive recovery of the magnetic iron ores and the phosphate ores can be realized.

The present invention relates to a cyclone suspension flash magnetizing roast-magnetic separation method for difficult-separable ironoxide ore. Its concrete steps are as follow: firstly, roasting the powdered difficult-separable ironoxide ore granules or fire-ground strong-magnetically-separated chats in the separation process under the condition of high-temperature reduction atmosphere and cyclone suspension fluidized state to make them be quickly dynamically reduced into magnetite within 5-100 sec. then adopting weak magnetic separation process to obtain high-quality acceptable iron headings.

The invention discloses a beneficiation method for a pure magnetic iron ore. A crude ore is sequentially treated according to the steps such as first crushing, first-stage dry-type magnetic dressing, medium crushing, second-stage dry-type magnetic dressing, fine crushing and third-stage dry-type magnetic dressing, fine ore is obtained after a great amount of gangues are thrown by the third-stage dry-type magnetic dressing and sent to a grinding head sieve to be griddled and separated, granules griddled by the grinding head sieve are treated in a first-section magnetic dressing process, rough ore griddled by the grinding head sieve is treated in a first-section ball grinding and then enters the first-section magnetic dressing process; ore aggregates obtained from the first-section magnetic dressing process are treated in a second-section ball grinding after discharging gangue sands till the granularity of ore powder is -200meshes being more than or equal to 60 percent, ore powder generated from the second-section ball grinder are treated in second-section magnetic dressing, ore aggregates generated from the second-section magnetic dressing are treated in a high-frequency sieve after discharging gangue sands, products positioned on the high-frequency sieve are filtered to obtain ore concentrate, and products positioned below the high-frequency sieve are treated with desliming and then treated with floatation. The invention adopts two sections of grinding ore open-way processes and distinguishes the ore aggregates during the ore dressing process, thereby greatly reducing the energy consumption of a system, lowering the production cost and enhancing the utility ratio of equipment.

The invention discloses a method for recycling valuable elements from vanadium-titanium magnetite ore, which comprises the following steps of: crushing the ore or concentrate, adding sodium salt, performing oxidizing roasting, converting vanadium and chromium into water-soluble sodium vanadate and sodium chromate, performing water leaching in solution, and separating the vanadium and chromium from the solution to obtain vanadium pentoxide and chromium sesquioxide products; and adding coal dust into the leached residue for pelletizing, reducing in a rotary hearth furnace, magnetically separating iron and titanium, using the obtained magnetic iron powder as a raw material for powder metallurgy or steelmaking, and using a nonmagnetic product containing more than 50 percent of TiO2 as a raw material for extracting the titanium; or reducing iron from the leached residue in an electric furnace, using the obtained molten iron as a raw material for steelmaking and using electric furnace slag containing more than 50 percent of TiO2 as a raw material for extracting the titanium. The method is short in process flow and economical; and the recovery rate of the vanadium, chromium, titanium and iron is high.

The invention relates to a dry presorting and tailings discarding process for ultra-poor magnetite, belonging to the technical field of magnetite presorting. The process comprises the following steps of: performing fine crushing on coarsely and intermediately crushed products with particle size not less than 70 mm through a closed loop to reach the particle size of 10-15 mm, performing dry weak magnetic rough sorting through a magnetic sorting machine with the magnetic field intensity of 1800-2000 Oe, and discarding a great amount of tailings with large particle size in advance; performing ultrafine crushing through a closed-loop high-pressure roller mill to reach the particle size of 3-5 mm, performing dry weak magnetic fine sorting through a magnetic sorting machine with the magnetic field intensity of 1600-1800 Oe, and discarding a great amount of tailings; and finally obtaining presorted concentrate. The discarding of a great amount of ultra-poor magnetite is realized, the grade of magnetite fed into a grinder is increased, the grinding cost is reduced, and the loss rate of magnetite is reduced. The process provided by the invention is easy to implement in the production in actual sorting plants and has high production efficiency, good product quality, energy saving, consumption reduction, low sorting cost and obvious economical benefit.

The invention belongs to the blast furnace ironmaking field and particularly relates to a new blast furnace ironmaking method by adopting common iron ore and vanadium titanium magnet to make iron, thereby not only guaranteeing the grade as fired but also lowering the production cost. When sintering ore is prepared by the method, the raw materials are mixed according to the following proportioning by weight: vanadium-titanium magnetite ore concrete of ranging from 35 to 50 percent, common iron ore of ranging from 30 to 45 percent, and fuel and fusing agent of 20 percent; part of the vanadium-titanium magnetite ore concrete is made into pellet ore independently; in the blast furnace ironmaking process, the pellet ore is mixed with the sintering ore and common lump ore to make iron, the blast furnace charging materials are mixed according to the following proportioning by weight: sintering ore of ranging from 60 to 65 percent, vanadium-titanium magnetite pellet ore of ranging from 25 to 35 percent, and common lump ore of ranging from 5 to 10 percent, wherein, the common lump ore contains bixbyite of about 2 percent. The method increases the use ratio of the vanadium-titanium magnetite by optimizing the furnace charging material structure, makes the best of the rich vanadium-titanium magnetite resources, lowers the production cost of the blast furnace ironmaking, and effectively increases the vanadium content in the molten iron, thereby having positive effects.

The invention discloses a pre-selecting and tailings discarding process of lean magnetite ores, comprising three stages: a coarse crushing stage, an intermediate crushing stage and an ultra-fine crushing stage, wherein fine crushing operation stage can be increased before the ultra-fine crushing stage and after the intermediate crushing stage. The staged magnetic pre-separation and tailings discarding work can be executed by different types of magnetic separators according to the difference of granularity of each crushing stage. Surrounding rocks and partial dissociatve gangue which drop in the tailings are removed in the first discarding work; waste stones which are not removed in the first tailings discarding work and the gangue which is further dissociated after the intermediate crushing stage are removed in the secondary tailings discarding work; and the third tailings discarding work is to discard the tailings after the tailings are ultra-finely crushed by a high-pressure roller mill. After the lean magnetite ores in which the fine particles are embedded are ultra-finely crushed by the high-pressure roller mill, the dissociation degree is further improved, and the magnetic separating and tailings discarding effects are good. The tailings discarding work is designed to reduce the loss of ferrous metal. The complete process can effectively improve the grade of grinding ferrous, can ensure the TFe recovery rate of the work, can improve the grinding characteristics of the material in the grinder, can reduce the quantity of the ore to be grinded, and can reduce the energy consumption of grinding the ores and the cost of separating the ores.

The present invention relates to magnetic field-responsive fibers, which comprise magnetite particles and a polymeric matrix. The invention also provides methods of producing the same, in particular via electrospinning of a stably dispersed or monodispersed polymer solution, either aqueous or organic, comprising the magnetite particles, and applications thereof.