34results about How to "Improve green ball quality" patented technology

The invention relates to a preparation method of high-chromium high-vanadium type vanadium-titanium ore pellets. The invention relates to a preparation method of vanadium-titanium ore pellets. With existing high-chromium high-vanadium type vanadium-titanium ore pellet preparation technologies, pellet superfusion is possible to occur, and pellet caking or nodulation are possible to occur, such that the quality of finished pellet product is influenced. The invention aims at solving the problem. The preparation method of the high-chromium-high vanadium type vanadium-titanium ore pellets comprises the steps of material blending, mixed drying, palletizing, green pellet screening, and shaft furnace roasting. Vanadium content of vanadium-titanium powder in the vanadium-titanium pellets is higherthan 4.5%, such that a requirement by blast furnace vanadium-titanium smelting is satisfied. The high-chromium-high vanadium type vanadium-titanium ore pellet preparation method provided by the invention is used for preparing vanadium-titanium ore pellets.

A composite additive for preparing hematite concentrate pellets comprises the following components: humic acid, calcium peroxide, and paigeite. During application, the composite additive is added which has a mass percent of 0.5%-1.6% of the total mass of the hematite concentrates, and the finished product pellets are obtained by pelletization, preheating, and roasting. Compared with pellets prepared by traditional technology, the hematite pellets prepared by the composite additive of the invention have improved falling strength of the green pellets, and compression strength of the finished product pellets; the preheating temperature and roasting temperature suitable for the pellets are reduced; both the preheating time and roasting time are shortened; the TFe grade is increased by 0.8%-1.2%. The composite additive of the invention has reasonable component ratios, is easy to process and manufacture, has a low using amount and a low residual amount, can significantly improve the pelletability of hematite concentrates which are difficult to be palletized, can improve the green pellet quality, has good heat stability, and can effectively reduce the preheating and roasting temperatures and shorten the preheating and roasting time of hematite concentrates. The composite additive of the invention is applicable to the production of oxidized pellets by hematites, and is especially applicable to the production of oxidized pellets by specularites. The composite additive of the invention is applicable to large-scale industrial production.

The invention relates to application of a shaft furnace to the roasting of full vanadium titanium iron ore concentrate pellet, which belongs to the technical field of the preparation method for the pellet. According to the method, the full vanadium titanium iron ore concentrate and 1.0 to 1.4 percent of bentonite are taken as raw materials which are used to prepare the full vanadium titanium iron ore concentrate pellet through even mixing, damp milling, pelletizing, drying and roasting, wherein the roasting temperature is 1,000 to 1,050 DEG C, and the roasting time is 30 to 60 minutes. The compressive strength of the full vanadium titanium iron ore concentrate pellet obtained by the method reaches 2,200N/piece. The pellet can be directly used for blast furnace smelting and also be used as a furnace protecting product during the blast furnace smelting of common ore.

The invention discloses a preparation technique of iron ore pellets, which comprises the following steps: (1) adding 0.5-1% of bentonite to iron concentrate, evenly mixing to obtain a mixture of which the water content is 1-3% lower than the propery pelletizing water content, pelletizing with a disk pelletizer or drum pelletizer, and when seed pellets grow into pellets with the diameters of 8mm or so, spraying fiberized bentonite in the pellet growth region to continue pelletization until qualified green pellets with the diameters of 12-16mm are obtained; and (2) the fiberized bentonite is prepared by the following steps: bentonite and a CMC (carboxymethyl cellulose) solution are mixed, so that smectite molecules in the bentonite sufficiently absorb water and expand under the actions of water molecules and CMC molecules under the action of mechanical stirring force, and spread to be compounded with the CMC molecules, thereby preparing the fiberized bentonite. The fiberized bentonite is atomized and sprayed to the pellet growth region to efficiently act on the iron concentrate granule surface and fully display the binding action, thereby obviously enhancing the quality of the green pellets and the strength of the preheated pellets and roasted pellets.

The invention discloses a finished pellet. The finished pellet comprises, by mass: 96.5%-98.4% of iron ore powder, 0.1%-0.5% of slaked lime and 1.5%-3% of calcium bentonite, and the mass fraction of Ca(OH)2 in the slaked lime is more than 88%. The invention also discloses a preparation method of the finished pellet. The preparation method comprises the steps of uniformly mixing the proportioned iron ore powder with the slaked lime and the calcium bentonite to obtain a mixture; and carrying out pelletizing, screening and roasting on the mixture to obtain the finished pellet. According to the finished pellet and the preparation method thereof, through adding the small amount of slaked lime, the specific surface area of the mixture can be improved, the falling strength and granularity uniformity of green pellets are further improved, and the quality of the green pellets is improved; the improvement of the quality of the green pellets is beneficial to the improvement of the circulation ofthe hot gas flow in a material layer, and sufficient oxidizing atmosphere is provided for the pellets in the roasting process, so that the content of FeO in the finished pellets is reduced; and the small amount of slaked lime plays a role of sulfur fixation, and the influence of the combination of sulfur and oxygen on the oxidation of ferrous iron is reduced.

The invention relates to a dust removing method in the production process of metallurgical pellets, in particular to a dust removing system of a chain grate machine tail part. The dust removing system comprises a chain grating machine tail part mechanism with a chain grate machine wheel and a chain grate machine tail wheel return device; the dust removing system is characterized in that a machine tail seal cover is arranged on the chain grate machine tail part mechanism; chain grate machine tail wheel return segment dust removing devices are arranged on the upper part of the machine tail seal cover; an overall chain grate machine tail dust removing device is arranged in the middle part of the machine tail seal cover; and a tail sealing wind box dust removing device of the chain grate machine is arranged at the end part of the lower return of the chain grate machine tail. According to the dust removing system provided by the invention, as the chain grate machine tail wheel return segment dust removing devices are arranged at the three main dust-raising spots of the chain grate machine tail mechanism, and are connected with external exhaust fans by pipelines, thereby forming a negative pressure environment; the three dust removing systems are compensated to one another and are linked with one another, so that the high temperature waste gas can be effectively prevented from overflowing, the tail machine environment of the chain grate machine workshop can be improved, the service life of the heat resistant parts of the equipment can be ensured; and moreover, the temperature gradients of the materials are smoothed, and the mine return quantity of the cured pellets can be reduced.

The invention discloses a pelletizing raw material loosening and blanking device and method. The pelletizing raw material loosening and blanking device comprises a base plate, enclosure plates, a material loosening plate, a vibrating plate and a driving device. The enclosure plates are welded to the four sides of the base plate. The vibrating plate is fixed to the middle of the lower surface of the base plate. Material loosening holes are evenly distributed in the upper portion and the lower portion of the base plate respectively. Material loosening bars penetrate through the material loosening holes. The lower ends of the material loosening bars are welded to the material loosening plate. The driving device is connected to the lower surface of the material loosening plate. The material loosening plate is movably connected to the base plate through shaft pins. The material loosening and blanking device is obliquely arranged between a feeding belt and a disc pelletizer. The material loosening bars vibrate at a certain frequency under the driving of the driving device, and thus pelletizing raw materials fallen onto the base plate are loosened into mineral powder with the uniform granularity; meanwhile, the base plate also vibrates continuously under the action of the vibrating plate, so that the mineral powder dispersed on the base plate is evenly distributed in a pelletizing disc. By the adoption of the pelletizing raw material loosening and blanking device and method, the dispersity of the pelletizing raw materials fallen into the pelletizing disc can be improved, the contact area between a green pellet and the mineral powder is increased, the pelletizing time is sufficient, and the quality of the green pellet is improved; the quality of returned materials is reduced, and the load of a screening system is reduced.

The invention discloses an iron ore pellet balling device. The device comprises an ore powder bin containing ore powder, an ore powder belt arranged below the ore powder bin, a first balling disc connected with the ore powder belt and a second balling disc arranged below the first balling disc. Ore powder falls onto the ore powder belt from the interior of the ore powder bin. Ore powder is conveyed into the first balling disc under the action of the ore powder belt, and green balls with the first weight are generated under the action of the first balling disc. Ore powder, not generating greenballs, in the first balling disc and the green balls with the first weight enter the second balling disc, and green balls with the second weight are generated under the action of the second balling disc. The technical effects that the ore return rate in the pellet balling process is greatly reduced, the yield is increased, the surface quality and strength of the green balls are improved, and energy consumption is reduced are achieved.

The invention discloses a sintered mixture magnetized water granulation process based on powder fuel electrostatic dispersion, and solves the problems of high water consumption, high energy consumption, unreasonable heat gradient distribution in the whole sintering process, adhesion to the inner wall of a cylinder mixer and poor operation stability in the water adding, uniform mixing and granulation process of the existing sintered mixture. The main technical scheme comprises the following steps: adding all sintering raw materials except the solid fuel into a primary mixing machine for mixing granulation, discharging from the primary mixing machine, feeding into a secondary mixing machine for further mixing granulation with the added solid fuel, and feeding into a sintering machine; wherein magnetized water is sprayed into the primary mixer to wet the sintering raw materials. The process is simple, energy-saving and consumption-reducing, easy to transform, low in operation cost, reasonable in gradient distribution of heat in the sintering process, high in burnout degree, long in service life of equipment and environment-friendly.

The invention discloses an active scraper optimization control to clean balling base bottom, which comprises the following steps: obtaining angular speed omega of disc balling machine, establishing track curved mathematic model, trace curved density mathematic model and mathematic model of covering index, taking covering index delta in the artificial program to optimize, affirming optimum parameter omegai for active scraper, inputting the optimum parameter omegai in the programmable controller PLC[5], connecting programmable controller PLC[5] and converter [6], connecting converter [6] and converting motor [7], driving the active scraper [8] by converting motor [7] through driving system.

The invention discloses a control method of pellet production. The method comprises the steps that basic performance parameters of iron ore powder are obtained, and the basic performance parameters comprise molecular water content, capillary water content, iron ore powder bulk density, iron ore powder true density and specific surface area; a comprehensive index K of iron ore powder pelletizationis determined according to the basic performance parameters; the pelletizing performance of the iron ore powder is determined according to the value of the comprehensive index K of the iron ore powderpelletization; and a corresponding preset process for pellet production is adopted according to the pelletizing performance of the iron ore powder. According to the above control method, the pelletizing performance of the iron ore powder can be judged more accurately, so that the corresponding preset process is adopted to control the pellet production, and the quality of fresh pellets of pelletsis significantly improved.

The invention relates to the technical field of iron and steel smelting, in particular to a ring formation control method through adding fine powder into rotary kiln oxidized pellets. The ring formation control method includes: utilizing a high-pressure roller milling system to perform high-pressure roller milling on the fine powder, adding the fine powder after roller milling in the process of producing the rotary kiln oxidized pellets, wherein specific surface area of the fine powder after roller milling is greater than that of the fine powder before roller milling; according to a sequence from inside to outside, sequentially arranging four passages of a main gun burner of a rotary kiln to be a coal gas passage, an inner flow air passage, a coal powder passage and an outer flow air passage; increasing pressure of a burning fan of the main gun burner. By using the ring formation control method, pelleting performance of the fine powder can be improved, and probability of ring formation in the kiln can be lowered.