208results about How to "Increase metallization rate" patented technology

The invention relates to a method to make low carbon sponge iron by microwave shaft furnace. It adopts iron ore powder as raw material, common soft coal dust or anthracite dust as reducer to gain high quality low carbon sponge. It uses the feature that the iron ore powder, carbon powder, and lime powder has selective absorbing to microwave. Under the condition of sealing and high temperature, and under the effect of microwave generator, heater, and adjustor, it would take carbon heat self-reduction by absorbing the heat produced by microwave generator to gain low carbon sponge iron. The method has simple technology, shortens the reduction time period, saves coking coal and coke resource, and reduces environment pollution. The degree of metallization could reach 90-98%, and the carbon content could be lower than 0.5%. It is the ideal method to make low carbon sponge iron.

The invention relates to a method for treating high-zinc iron-containing slime through utilizing a rotary kiln. The method comprises the steps that blast furnace gas ash and converter OG mud are mixed and pelletized; wet pellets are dried and preheated, and a drying and preheating heat source is hot air generated by high-temperature flue gas of the rotary kiln after passing through a high-low temperature composite air heat exchanger; a pea coal spray gun, a carbon residue spray gun and an ore grain spray gun are arranged at a kiln head of the rotary kiln, and high-volatile matter coal, residual carbon and high-grade iron ore are sprayed into the kiln; the dried pellets are fed into the rotary kiln, and high-temperature metallized pellets are obtained after the dried pellets are subjected to direct reduction and high-temperature solidification in the rotary kiln; after being cooled to the normal temperature, materials like the metallized pellets and excess carbon residue are subjected to magnetic separation, and metallized pellets are obtained; and large-particle dust is removed from the high-temperature flue gas of the rotary kiln, the high-temperature flue gas enters the high-low temperature composite air heat exchanger to be cooled, the cooled flue gas enters a bag-type dust collector, and zinc oxide powder is recycled. According to the method, the high-zinc iron-containing slime generated by iron and steel enterprises is efficiently utilized, and environmental pollution caused by stacking of the high-zinc iron-containing slime is solved.

The invention relates to a method for reinforcing preparation and reduction of carbon-containing pellets in iron ore. The method for reinforcing preparation and reduction of the carbon-containing pellets in the iron ore comprises the following steps that (1) the iron ore, a reducing agent, a bonding agent and an additive are prepared according to a certain proportion; (2) prepared mixtures are sent into a ball mill to be crushed, fine ground, evenly mixed and the like, so that fine-sized evenly-mixed materials are obtained; (3) pelletizing or briquetting is conducted by means of the fine-sized evenly-mixed materials, so that the carbon-containing pellets in the iron ore are obtained; and (4) the prepared carbon-containing pellets in the iron ore are subjected to reducing roasting treatment, and thus metallized pellet products can be obtained. According to the method for reinforcing preparation and reduction of the carbon-containing pellets in the iron ore, in the way that the raw materials including the iron ore, the reducing agent, the bonding agent, the additive and the like enter the mill simultaneously after being prepared, the dual effects of fine grinding and sufficient and even mixing of the raw materials are achieved at the same time in the single ore grinding procedure, and the procedure links of fine grinding raw materials separately in advance, then preparing the raw materials in proportion and finally conducting even mixing of traditional operation are greatly simplified; and the quality of the carbon-containing pellets in the iron ore is remarkably improved, and the subsequent reduction process is reinforced.

The invention discloses a method for preparing steel smelting furnace materials from a phosphorus-containing globulitic hematite. The method comprises the following steps: adding adhesives with certain proportion into a globulitic hematite which is broken and grinded to the granularity smaller than 0.074mm and has the mass percentage of 50% to 60%, mixing evenly, then, agglomerating, reducing and sintering dried blocks with coal as reducing agent with the sintering temperature of 1000 to 1050DEGC and with the time of 2 to 1.5h, breaking and grinding cooled reduced blocks to smaller than 0.074mm with the mass percentage of 80% to 90%, magnetically selecting and separating the blocks with the magnetic field intensity of 0.1 to 0.12T, and obtaining the metal iron powder, wherein the adhesive is mixed by sodium sulfate powder, solubor, natrium humate and sodium xanthonate, the mass percentage of sodium sulfate powder in the hematite is 5% to 8%, the mass percentage of solubor in the globulitic hematite is 1% to 2%, the mass percentage of natrium humate in the globulitic hematite is 0.5 % to 1%, and the mass percentage of sodium xanthonate in the globulitic hematite is 0.5 % to 1%. The method has high utilization efficiency, excellent dephosphorization effect, excellent product quality, high iron recovery rate, low cost and low environment pollution.

The invention relates to a process for treating and comprehensively utilizing a vanadium-titanium magnetite. The process is characterized by comprising the following steps: (1) treating a raw vanadium-titanium magnetite by crushing, tailings discarding, fine grinding, low-intensity magnetic separating, high-intensity magnetic separating, and separating by a shaking table, so as to obtain a titanium concentrate and a high-vanadium-ferrum concentrate; (2) adding an adhesive to the high-vanadium-ferrum concentrate; uniformly mixing and pelletizing; drying; uniformly mixing with pulverized coal or coke powder; distributing; performing controlled reduction that V is not reduced through a coal based shaft furnace so as to obtain sponge iron, wherein the amount of used reducing agents such as the pulverized coal is 30 to 70% of the weight of high-vanadium-ferrum concentrate powder, and the reduction is performed for 10 to 18 hours at the temperature of 850 to 1060 DEG C; (3) heating the obtained sponge iron for 0.5 to 1.0 hour at the temperature less than 1050 DEG C through an intermediate frequency / main frequency furnace under a weak reduction atmosphere; then heating until the temperature is more than 1500 DEG C; performing melt separation to enable vanadium to enter slag, thus obtaining high-grade vanadium slag and high-purity molten iron. With the adoption of the process, a plurality of valuable elements in the vanadium-titanium magnetite can be effectively separated and utilized with high additional value.

The invention relates to the making of micron and sub-micron metal powder, which firstly ball grinds the oxidized metal powder with heating environment, entering nitrogen or argon gas or their mixture till the content of metal powder <=10 micron, heating it to 200-400deg.C, feeding recovery gas H2 or mixture of H2 and CO to switch nitrogen and argon or their mixture for 30-6000 min, removing the water and CO2, boosting to back to the ball grinding for reaction, inactivating the recovered iron powder. It is low in cost and energy consumption, simple in production process, easy in making, suitable for mass production.

The invention discloses an industrial production method of separating valuable elements from composite paragentic mineral of aluminum-vanadium-titanium-iron-silicon for cyclic utilization. The method comprises the following steps: employing the technique of gradient magnetic separation to separate aluminum-silicon-iron products, vanadium-titanium-iron products and sulfur concentrate from composite paragentic mineral of aluminum-vanadium-titanium-iron-silicon; carrying out flash suspension smelting on the aluminum-silicon-iron products to obtain ferrosilicon alloy and aluminum slag which is used as a raw material for production of alundum; employing the technique of rectilinearly movable bed prereduction-shaft furnace smelting to prepare the vanadium-titanium-iron products into vanadium iron intermetallic compounds and titanium slag. Smelting separation and flash suspension smelting and rectilinearly movable bed prereduction-shaft furnace smelting are combined in the method provided inthe invention, which enables the recovery rate of raw ores to be enhanced.

The invention discloses a method for realizing dephosphorization of olitic high-phosphorus iron ore by use of biomass charcoal, which realizes direct preparation of low-phosphorus liquid iron by combining direct reduction and high-temperature scrap iron separation. The method comprises the following steps of: preparing high-gasification biomass charcoal; breaking the ore charge; preparing carbon addition-lack carbon-containing pellets; performing direct reduction; and performing high-temperature melting. Compared with the existing method for treating olitic high-phosphorus iron ore, the method disclosed by the invention prepares the carbon addition-lack carbon-containing pellets by taking the widely-available and low-price biomass charcoal as a reducing agent and performs direct reduction in a CO / CO2 mixed atmosphere, and obtains low-carbon residue high-metallization pellets by use of the good gasifying performance of the biomass charcoal under the catalysis of Na2CO3; and the reinforcing effect of Na2O on the dephosphorization of liquid iron is obtained by use of Na2CO3 decomposition in a high-temperature scrap iron separation stage. Since the ash content of the biomass charcoal is low, the slag content in a high-temperature melting process is low. The method disclosed by the invention has the characteristics of high iron recovery rate, good dephosphorization effect and the like.

The invention relates to a CEO compound smelting reduction ironmaking plant and technology. The CEO compound smelting reduction ironmaking plant comprises combination of a vertical furnace, a pre-reduction furnace, an electric furnace, and a cyclone furnace which is arranged on the lateral wall of the electric furnace, wherein an outlet of the vertical furnace is directly connected with an inlet of the pre-reduction furnace; the pre-reduction furnace is connected with the electric furnace through a pipeline; the cyclone furnace is connected with the electric furnace through a pipeline. The technology comprises the following processes: firstly, preparing phi 10-40mm of carbon-containing pellets from iron ore powder, pulverized coal, lime and a binder; drying the carbon-containing pellets by using flue gas of 160-500 DEG C inside the vertical furnace and then feeding the dried carbon-containing pellets to the pre-reduction furnace connected with the vertical furnace; carrying out pre-reduction at the temperature of 300-1450 DEG C of the flue gas discharged from the inside of the electric furnace, and feeding the pre-reduced carbon-containing pellets to the electric furnace; and carrying out reduction and smelting separation at the temperature of 1500-1800 DEG C, wherein the cyclone furnace supplies a high-temperature gas of about 1000-1500 DEG C to the electric furnace by taking coal, air and oxygen as raw materials. The process disclosed by the invention has the characteristics of high energy efficiency, and high recovery rate of iron; kinds of coals and iron ores are used.

The invention relates to a coal-based direct reduction-melt separation furnace smelting reduction iron-making process using an external heating mode. Equipment used in the process comprises a pellet drying chamber, a distributing device, an external heating type reduction furnace and a melt separation furnace which are arranged from top to bottom. The process includes the steps that S1, carbon-bearing pellets are preheated and dried in the pellet drying chamber; S2, the carbon-bearing pellets in a reduction chamber are continuously and evenly heated, and the carbon-bearing pellets are quickly reduced in the reduction chamber; S3, high-temperature metallized pellets are obtained after the carbon-bearing pellets in the reduction chamber are reduced, and the high-temperature metallized pellets are charged into the melt separation furnace in a hot-delivery and hot-charging mode to be subjected to reduction smelting; S4, after the metallized pellets enter the melt separation furnace, the melting point, the viscosity and the separating effect of slag iron are controlled through the content of added flux and pulverized coal, reduction smelting of the metallized pellets is completed, and accordingly high-quality molten iron and high-temperature furnace slag are obtained. By the adoption of the process, iron ore which is low in grade and difficult to reduce is utilized comprehensively, the technological process is shortened, production cost is lowered, product quality is improved, and production efficiency is effectively improved.

The invention discloses a method for preventing excessive fusion of prereduced sinter, the method is characterized in that: during sintering material arrangement, three carbon containing pellets are respectively arranged in three layers of an upper layer, a middle layer and a lower layer, wherein the three carbon containing pellets are different in granularity, and the upper pellet granularity is small and the lower pellet granularity is large. The upper layer accounts for 45%-55% of the total mass of the sinter bed, the middle layer accounts for 25%-35% of the total mass of the sinter bed, and the lower layer accounts for 15-25% of the total mass of the sinter bed. The granularity range of the carbon containing pellets is 3mm-12mm, the carbon containing pellets are prepared by mixing an iron material, a carbon containing raw material and a binder, and after material arrangement, prereduced sintering is performed to obtain the finished prereduced sinter. The advantages and effects of the method are in that: through layered arrangement of the sintered pellets with different carbon contents and granularity, the sinter bed permeability is increased, the fuel use rate and prereduction sintering utilization coefficient are improved, and the quality of the prereduced sinter is improved. The middle layer and the lower layer of the sintering material use large pellet sintering, petroleum coke is added in the pellets, the petroleum coke has good reactivity at low temperature and has a reduced reactivity at the temperature of more than 1300 DEG C, so that excessive fusion of the material layer in a sintering process can be prevented, and the metallization ratio of the prereduced sinter is improved.

The invention relates to a mineral processing technology for reducing, roasting, iron extraction and impurity removal of limonite. The mineral processing technology is characterized by comprising the steps: raw material preparation, agglomeration, drying treatment, reduction roasting, water quenching of roasted materials, screening wet preconcentration, stage grinding and magnetic separation. With the adoption of the mineral processing technology for reducing, roasting, iron extraction and impurity removal of limonite, the metallization ratio is 90-95 percent, the recovery ratio of iron reaches 90-95 percent, and tailings with the grade of 5-10 percent is final tailings.

The present invention discloses an orbicular sponge iron and the producing method used for treating water, which belongs to the metallurgy manufacturing technology region. The present invention is used for providing an orbicular sponge iron and the producing method used for treating water with appropriate grain diameter, high deoxidized iron content and much less iron crystal grain. The present invention is characterized in that: the grain diameter of the orbicular sponge iron is 1-5mm; the crystal grain is less than 10um, and the metal ratio is more than 90 percent. The preparation steps in the present invention consists of material-mixing, making sphere, oxidation sintering and direct deoxidization and so on. The present invention is developed according to the requirement for the zero-price iron material of the treated water; the method can develop an orbicular sponge iron, which can wipe off the deleterious and baneful infectant such as heavy metal, nitrate, and chlorine organic substance and so on in the water. Compared with the existing industrial sponge iron or other common zero-price iron material, the product is characterized in that the inner iron crystal grain is micron, the surface area is larger, the surface energy is higher, the deoxidization ability is stronger and the metal ratio is higher. The product is with some intensity, which can avoid the pulverization and hardening in the water treating process. The method and device of the present invention has the advantages of simple technical and low manufacturing cost.

The invention provides a combined direct reduction technology of blast furnace gas ash and refractory low-grade iron ore in a tunnel kiln. The combined direct reduction technology mainly comprises the following processing steps: (1) burdening and mixing the iron ore with grain sizes of 0-3mm and the blast furnace gas ash so as to obtain fine-graded materials; grading the iron ore with grain sizes of above 1mm according to different grain size ranges, burdening and mixing the iron ore and reduced coal in the same grain size range so as to obtain coarse-graded materials; (2) sequentially laying the fine-graded materials and the coarse-graded materials on a fire-resistant thermal conducting plate of a kiln car of a tunnel kiln from top to bottom; and (3) placing the materials in the tunnel kiln along with the kiln car so as to carry out high temperature reduction. The combined direct reduction technology has the advantages that the blast furnace gas ash is effectively utilized, and the utilization efficiency of carbon in the blast furnace gas ash is greatly improved; by adopting a layering distribution step-by-step oxygenation reduction method, the metallization ratio of iron ore direct reduction is increased, and the reduction time is shortened; and the iron grade of metallizing iron powder produced by the technology reaches above 84%, and the metallization ratio reaches above 88%.

The invention discloses a method for producing a ferrochromium alloy by two-step-process smelting reduction of ferrochromium mineral powder. The method comprises the following steps: (1) preparing raw materials, namely uniformly mixing the ferrochromium mineral powder with coke powder, and pelletizing on a disk pelletizing machine; (2) performing pre-reduction, namely uniformly distributing green pellets on a chain grate, preheating and drying the green pellets, loading the green pellets which are preheated and dried into the rotary kiln for pre-reduction, and burning by using coal gas generated by a final reduction section iron bath furnace for heat supply, wherein an adopted heat source is kiln tail waste gas from a rotary kiln; (3) performing final reduction, namely adding high-temperature pre-reduction pellets from the top of the iron bath furnace through a spiral discharger, thermally loading the pellets into the iron bath furnace for melt separation, spraying coal powder and oxygen into an iron bath by utilizing a coal oxygen spraying gun, burning the coal powder and the oxygen in the iron bath, supplying heat needed by the melt separation, after the melt separation is completed, performing slag iron separation, and discharging iron and slag. According to the method, the ferrochromium mineral powder can be largely treated, and utilization of powder mines is improved, so that the production cost of the ferrochromium alloy is reduced, and large-scale production is facilitated.

The invention discloses a microwave-fuel combined heating-type coal-based direct reduction method and a rotary hearth furnace. The method comprises the following steps of drying and pre-heating materials, reducing the materials by a fuel combustion method, and further reducing the materials by a microwave radiation method, wherein a reducer for reducing the metal oxide into metal is fixed carbon in the materials. The rotary hearth furnace is used by the above method. The rotary hearth furnace has the advantages of simple structure, low cost, high metallization rate, and realization and popularization easiness.

The invention relates to the technical field of metallurgical and mineral engineering and discloses a high-alkalinity composite metallized pellet for a converter and a production process thereof. The pellet comprises an inner core and a shell wrapping outside the inner core, wherein the inner core is prepared through mixing coal powder, limestone and cement according to the mass ratio of 100: (300-550): (4-7), the shell is prepared through mixing iron concentrate and bentonite according to the mass ratio of (1,500-1,800): (30-54), the granularity of the inner core is 20-25mm, and the thickness of the shell is 5-10mm; the outside of the shell is further covered with a layer of reducing agent. The production process comprises the steps of preparing the inner core, wrapping the shell to form the composite metallized pellet, wrapping the external wall of the composite metallized pellet with a reducing layer, distributing and drying the composite metallized pellet, carrying out reduction roasting on the composite metallized pellet, cooling and separating the high-temperature-reduction composite metallized pellet, and the like. According to the high-alkalinity composite metallized pellet and the production process thereof, through proportionally adding the limestone and the coal powder into the inner core, the internal reducing atmosphere of the pellet is strengthened, the reduction rate is increased, and the energy consumption is lowered.

The invention relates to a stainless steel dust rotary kiln direct reduction treatment process. The stainless steel dust rotary kiln direct reduction treatment process comprises the steps that (1), stainless steel dust and reducing coal are dosed and mixed according to a ratio of 100:(10-20), and granular materials with a water content of 10-12% and a particle size of 3-5mm are prepared; (2), thegranular materials are dried and preheated in a preheating zone of a rotary kiln and are entered a high-temperature reduction zone and are reduced at a temperature of 1100-1200 DEG C for 90-120 minutes, high-volatile pea coal and high-grade grain ore are injected into the rotary kiln for carbon and hydrogen combined reduction and carbon cycle oxygenation reduction in a middle-late stage of dust reduction, so that the stainless steel dust can be sufficiently reduced in the rotary kiln; and (3), high-temperature calcined materials from the rotary kiln are subjected to cooling and magnetic separation, and granular metallized products used in a power supply furnace or a converter can be obtained. According to the stainless steel dust rotary kiln direct reduction treatment process, while processing stainless steel dust from iron and steel enterprises, the iron, nickel and chromium resources in the dust mud are effectively utilized to produce high-quality metallized materials containing nickel and chromium.

The invention discloses a comprehensive treatment method for vanadium slag and application thereof. The comprehensive treatment method for the vanadium slag includes the steps that the vanadium slag, sodium salt and a reducing agent are subjected to mixing and briquetting treatment, so that mixed material briquettes are obtained; the mixed material briquettes are subjected to reducing smelting treatment, so that metalized briquettes are obtained; the metalized briquettes are subjected to grinding magnetic separation treatment, so that reduced iron and vanadium-rich slag are obtained; the vanadium-rich slag is subjected to oxidizing roasting treatment, so that vanadium slag clinker is obtained; and the vanadium slag clinker is subjected to vanadium extraction treatment, so that vanadium pentoxide is obtained. According to the comprehensive treatment method, the vanadium slag, the reducing agent and the sodium salt are mixed, then the iron in the vanadium slag is recovered through reducing smelting, vanadium is enriched after the iron is recovered from the vanadium slag, and the vanadium-rich slag is obtained; and the vanadium-rich slag is subjected to oxidizing roasting to obtain water-soluble sodium vanadate, and the vanadium pentoxide is extracted from the vanadium slag. The comprehensive treatment method for the vanadium slag realizes step-by-step extraction of valuable elements of the iron and the vanadium in the vanadium slag, and the recovery rate of the iron and the vanadium is high.

The invention discloses a method for separating metal iron from phosphorus containing iron ore. The method includes the following steps: (1) fine grinding the phosphorus containing iron ore to obtain iron ore powder; (2) pelletizing the iron ore powder to obtain iron ore pellets; (3) drying the iron ore pellets to obtain dried iron ore pellets; (4) roasting the dried iron ore pellets to obtain roasted iron ore pellets; (5) performing gas-based reduction on the roasted iron ore pellets in a shaft furnace at the temperature of 800-900 DEG C to obtain metallized pallets; (6) performing melt separation under the nitrogen atmosphere after the metallized pallets are mixed with a fluxing agent and a dephosphorization agent to obtain metal iron and phosphorus containing tailings. The method can be used for effectively separating phosphorus in phosphorus containing iron ore, so as to obtain the metal iron with the phosphorus content lower than 0.2 wt% after separation.

A high purity of molten iron is produced efficiently at a higher productivity, by feeding a raw material mixture containing a carbonaceous reducing agent, an iron oxide-containing material and a CaO-containing material onto a hearth of a moving-hearth reducing furnace, heat-reducing the raw material mixture in the reducing furnace, and melting it in a melting furnace melting, wherein a blending amount of the CaO-containing material in the raw material mixture is adjusted in such a manner that another feeding of the CaO-containing material into the melting furnace makes a basicity of a slag generated in the melting furnace 1.1 or more an feeding amount of the CaO-containing material becomes 40 kg or less per ton of the molten iron obtained in the melting furnace.

The invention relates to a QDF (quiescent direct furnace) direct reduction technology which comprises the following steps: uniformly mixing a metal-containing raw material and reducing agent powder, and putting into each reducing chamber, wherein in a reducing process, the reducing chambers and the reduced material are all kept in a stationary state; uniformly heating the materials in the reducing chambers by use of the heat generated by the combustion of the fuel in a combustion chamber and a combustion-supporting gas so as to perform a reduction reaction between the metal-containing raw material and the reducing agent, wherein each reducing chamber is a narrow long one-section reactor. According to the technology provided by the invention, the reducing chambers and the reduced material are all in a stationary state, the requirement on the strength of the granular raw material is reduced, and the production efficiency of a granulation process is improved; and the reducing time can be prolonged, and the metallization ratio of the reduction product is improved. The reducing chamber is not provided with a preheating area or a cooling area, the temperature is uniform, the atmosphere is uniform and consistent, and the overall quality of the reduction product is improved. The direct reduction technology has remarkable advantages of wide application range of raw materials, uniform temperature field, easy control on reduction process, high product metallization ratio, high yield and the like.

The invention relates to a microwave shaft furnace direct reduction process adopting pellets and coal powder. According to the process, direct reduced iron is produced from raw material pellets and external matched material coal powder in a continuous microwave shaft furnace, selection heating, rapid heating, volume heating, activated metallurgical chemical reaction and other features of the microwave are fully utilized, gasification of fixed carbon is accelerated, and iron oxide is further reduced, so that the reduction temperature is lowered and the reaction time is shortened. The coal powder can serve as both a reducing agent and a heating element in the process, a gas-solid-heat exchange step is simplified, energy is saved and emission is reduced. The process contains low free oxygen content, and can produce CO with high purity of 95% or above; and the process is compact in structure, high in metallization degree, which is 94-98%, low in carbon content, which is less than 0.2%, andis low in quality requirements on coal powder, thereby being an environment-friendly iron making process.

The invention provides a method for preparing high titanium slag through low temperature reduction and separation of titanium-containing iron ore. According to the method, a pre-oxidation titanium-containing iron ore raw material is used, and a carbonaceous reducing agent and smelting reduction catalysts such as Na2SO4 and FeS are used for reduction production of pig iron and high titanium slag products; compared with a traditional electric furnace smelting titanium slag process, a product can be obtained through reduction for 20 minutes to 40 minutes at a lower temperature ranging from 1200 DEG C to 1500 DEG C, the reduction speed is higher, energy consumption is lower, cost is reduced, and the aims of separating the pig iron and the titanium slag with high efficiency, low consumption and low cost are achieved; meanwhile, the metallization recovery rate of the iron element is improved, and the grade of the obtained high titanium slag is higher; in addition, the main ingredient of tail gas in the reduction process is CO and can be recycled, and the reduction and heating energy consumption is further saved; accordingly, a new process is provided for producing the high titanium slag, and the problems that in the prior art, a high titanium slag preparing process is complex, the production efficiency is low, cost is expensive, and the energy consumption is large are solved.

The invention discloses a ferrochrome preparation method. The ferrochrome preparation method comprises the following steps: (1) mixing chromite ore fine, a reducing agent, a reducing assistant, a nucleating agent and a binder to conveniently obtain a mixed material; (2) adding water into the mixed material for pelletizing to conveniently obtain mixed pellets; (3) drying the mixed pellets to conveniently obtain dry pellets; (4) performing reduction treatment of the dry pellets in a reduction roaster to conveniently obtain metallic pellets; (5) cooling down the metallic pellets in a seal pot to conveniently obtain cooled pellets; and (6) performing crushing and magnetic separation of the cooled pellets to conveniently obtain ferrochrome and tailings. The ferrochrome preparation method can effectively utilize chromite powder resource and is low in production cost and simple in process, and chromium in the obtained ferrochrome is high in grade.

PCT No. PCT / JP97 / 00164 Sec. 371 Date Sep. 23, 1997 Sec. 102(e) Date Sep. 23, 1997 PCT Filed Jan. 24, 1997 PCT Pub. No. WO97 / 27337 PCT Pub. Date Jul. 31, 1997A method for operating a shaft furnace which comprises charging the furnace with an iron source having a low degree of metallization and thus requiring reduction, an iron source having a high degree of metallization and thus requiring nothing but melting, and a solid fuel, and blowing an oxygen-containing gas at ordinary or higher temperature up to 600 DEG C. into the furnace through tuyeres to reduce and melt the iron sources. The optimal values of eta co (gas utilization factor) are determined from the average degree of metallization of the iron sources, and the shaft furnace is controlled so that the effluent gas from the furnace has the optimal eta co values. The control is accomplished by regulating the height of the charge, regulating the height of the coke bed, etc., using multistage tuyeres, and radially partitioning the charge. Thus, the iron sources can be efficiently reduced and melted at a low fuel ratio.

The invention provides a method and system for preparing a metallized pellet. The method for preparing the metallized pellet comprises the steps that an iron containing raw material, reduction coal, a fluxing agent and a binder are subjected to first mixing, so that a first mixed material is obtained; the first mixed material is subjected to first pelletizing treatment, so that a mother ball is obtained; metal iron powder and the binder are subjected to second mixing, so that a second mixed material is obtained; the mother ball and the second mixed material are subjected to second pelletizing treatment, so that the mother ball is wrapped by the metal iron powder, and a composite carbon-containing pellet with the mother ball as a core is obtained; the composite carbon-containing pellet is conveyed into a rotary hearth furnace to be distributed in many layers, and direct reduction treatment is carried out in the rotary hearth furnace, so that the metallized pellet is obtained; and the metallized pellet is subjected to ball grinding and magnetic separation treatment, so that metal iron powder and tailings are obtained. By means of the method, the distribution thickness can be effectively increased, surface pellet melting can be effectively avoided, and the metallization ratio and reduction uniformity of the multi-layer pellet are increased.

The invention discloses a method for preparing chlorinated titanium-enriched materials by fine-particle Panxi titanium concentrates. The method comprises the following steps: the fine-particle Panxi titanium concentrates are molded and pressed as balls after oxidation roasting and mixing and ball milling with carbon reducing agents, additives and binding agents, are heated under an Ar atmosphere after reduction, and are crushed, milled and magnetically separated to obtain magnetic products and nonmagnetic pulp; the nonmagnetic pulp is filtered and dried to obtain fine-particle titanium-enriched material semi-finished products; dilute hydrochloric acid is used for acid leaching; and the chlorinated titanium-enriched materials are obtained through fusion recrystallization, crushing and screening by the obtained fine-particle titanium-enriched materials. High-grade iron powder can be directly obtained after magnetic separation; the grade MFe of the iron powder is higher than 84%, so thatthe iron powder can be directly sold as products; the grade of titanium dioxide of the chlorinated titanium-enriched materials is higher than 90%; and through fusion recrystallization, the particle size remolding of the fine-particle titanium-enriched materials can be realized, the titanium-enriched materials of 60-140 meshes are more than 85%, and the particle size requirements of the chlorinatedtitanium-enriched materials can be met.

The invention provides a vanadium titanium magnetite treatment device which comprises a rotary kiln, a coal injection device, an electric furnace and a converter. A reaction cavity used for carrying out prereduciton on vanadium titanium magnetite is limited in the rotary kiln, the rotary kiln is provided with a feed inlet for feeding raw materials into the rotary kiln, a roasted ore outlet for discharging roasted ore and an air outlet used for exhausting smoke gas, the oil injection device is arranged on the rotary kiln for injecting fuel into the reaction cavity, the electric furnace is usedfor smelting roasted ore and provided with a roasted ore inlet, a slag outlet, an iron outlet and a smoke outlet, the roasted ore inlet is used for adding roasted ore, titanium slag and vanadium-containing iron water obtained through smelting of the electric furnace are discharged from the slag outlet and the iron outlet, smoke gas in the electric furnace is exhausted from the smoke outlet, the rotary kiln is used for blowing vanadium-containing iron water, the rotary kiln is provided with an adding inlet, a slag discharge outlet and a discharge outlet, the adding inlet is used for adding vanadium-containing iron water drained from the iron outlet, and vanadium slag and semisteel produced through blowing of the rotary kiln are discharged from the slag discharge outlet and the discharge outlet. The vanadium titanium magnetite treatment device is simple in structure, short in flow, low in energy consumption, small in pollution and low in cost.