35results about How to "Raise the reduction temperature" patented technology

The invention provides an iron ore shaft furnace-rotary kiln direct reduction process for producing iron powder, which includes the following process steps: (1) after the iron ore is ground, it is enriched by magnetic separation, and the obtained rough concentrate powder is mixed with bentonite Afterwards, carry out grinding and pelletizing to obtain pellets; (2) Pellets are added from the top of the shaft furnace, and the pellets are fully heated, oxidized and consolidated in the shaft furnace; (3) Oxidized pellets Mix it with granular coal and add it to the rotary kiln for reduction; (4) Put the reduced pellets into the waste heat recovery device, so that the pellets and air can perform indirect heat exchange; (5) The materials discharged from the waste heat recovery device are magnetically The metallized iron powder with a metallization rate of more than 85% and an iron grade of more than 80% can be obtained. The invention solves the problems of low pellet strength and easy generation of liquid phase in the direct reduction of refractory low-grade iron ore, improves the reduction temperature of the pellets in the reduction roasting rotary kiln, shortens the reduction time, and reduces the number of pellets. powdering phenomenon.

The invention relates to a method for extracting high-content nickel, chromium and iron from stainless steel dust, which is characterized by comprising the following steps of: mixing the stainless steel dust, coal powder and limestone, then adding an adhesive for manufacturing green balls, adding the obtained green balls into a rotary hearth furnace, firstly oxidizing the green balls rotating along with a hearth through an oxidation zone in the rotary hearth furnace, then reducing the green balls through a high-temperature reduction zone in the rotary hearth furnace, finally reducing the green balls into high-temperature mature balls, discharging the mature balls out of the rotary hearth furnace, then naturally cooling, naturally powdering the slag in the cooled mature balls, naturally powdering iron slag, and sieving to obtain iron grains directly used for steelmaking. The method thoroughly changes a traditional process route, the atmosphere component control in the rotary hearth furnace is optimized by improving the proportion of raw materials, a product can be obtained through one-step smelting, the process route is simplified, the production energy consumption is also greatly reduced, the cost is greatly lowered, and the product is quite competitive.

The invention belongs to the field of metallurgical technology, and more particularly relates to a technique for preparing nickel-iron alloy. The technique aims at solving the technical problem of providing the technique which is used for preparing nickel-iron alloy, has high production efficiency, short process flow and low energy consumption, takes common coal as reducing agent and ensures burden not to be easily agglomerated. The technical scheme comprises the steps: A. after mixing nickel oxide-containing raw material, pulverized coal and fusing agent, pelletizing the mixture; B. reducingpellets and obtaining metalized pellets; C. smelting the metalized pellets and obtaining crude nickel-iron alloy; D refining the nickel-iron alloy and obtaining refined nickel-iron alloy. The technique has the raw material which is internally provided with pulverized coal pellets, enlarges the reaction area, improves the dynamical condition and is beneficial to the reduction process. Furthermore,the technique has the advantages of short reduction time, low energy consumption, less dust and high recovery rate of useful elements as well as ensuring the pellet burden not to bond a furnace lining.

The invention relates to a roasting method of efficiently controlling iron ores to be magnetized. The method comprises the following steps: by virtue of agile adjustment of components, flow and pressure of reduced gas, improving the content of hydrogen in the reduced gas; controlling the content of hydrogen at 15%+ / -3%; greatly improving the diffusivity and thermal conductance of the reduced gas; obtaining the optimal effect of the roasting method of efficiently controlling iron ores to be magnetized. Meanwhile, aiming at the problem that the reduced gas in the roasting method excessive, the reduced gas is reduced from 1800-2000m<3> / h to 1000-1200m<3> / h, the consumption of the reduced gas is reduced by 800m<3> / h, the production cost is lowered, and the environmental pollution by CO in exhaust gases in a shaft furnace is eliminated. The reducing temperature of the iron ores is improved to 680-720 DEG C, and a good reducing temperature is provided for reducing block iron ores. Meanwhile, the pressure of the reduced gas is controlled at 5000Pa+ / 200Pa, so that the iron ores can be fully and uniformly roasted.

The invention relates to an upward-inclined trapezoidal wave interface device applied to a three-cyclone biomass gasification combustor and belongs to the technical field of biomass combustion equipment. When the three-cyclone biomass gasification combustor is in a use process, fuel is combusted to form gas; the gas flows smoothly via annular trapezoidal openings which are uniformly formed in thebottom of an annular trapezoidal wave interface; the flow speed of the gas is reduced; the quantity of sparks carried in the flame in combustion of the three-cyclone biomass gasification combustor canbe effectively reduced; meanwhile, under the effect of a necking type reduction chamber, the speed of the gas is effectively reduced and the gas is gathered at the top of an annular square opening; under a heat accumulation effect, hot gas flow can obtain a relatively high reduction temperature, thus the carbon dioxide in hot smoke which enters the reduction chamber from an annular fire layer anda bottom fire layer can be effectively reduced into carbon monoxide; the fuel is effectively combusted; and smoke emission is reduced.

The invention discloses a coal-based direct reduction method and a rotary hearth furnace with microwave fuel combined with heating. The material is further reduced by radiation; the reducing agent required for metal oxide reduction to metal comes from the fixed carbon in the material. The rotary hearth furnace is an apparatus based on the method described above. The invention has the advantages of simple structure, low cost, high metallization rate, easy realization, popularization and application, and the like.

The invention provides a process for production of direct reduced ferrum with coal as a reducer: covering the surface of pellet with a protective layer made up of inorganic inert substance with disk cuber or cylinder cuber after the iron material is made into pellet basing on the present technology, then covered pellets being produced, sending the covered pellets into the kiln to run reduction reaction, after reduction sending the covered pellets into cooling barrel and cooling them rapidly, then disintegrating or grinding and letting the inorganic inert substance release the pellets, the direct reduced ferrum pellets being obtained after sifting. Producing direct reduced ferrum with the method, pellets don't bind with each other, or with retort, and the temperature of the inside of kiln can be raising to 1100 to 1250 deg, as a result, the reduction reaction rate and metallising ratio are highly increased, and the productive efficiency and productive cost improved.

The invention discloses a metallized pellets reduction method by pulverized coal and a shaft furnace. The method comprises steps of fabricating pellets of iron ore powder or powder of other metallic oxide ore, putting the pellets into the shaft furnace by a set quantity measurement, raw coal with a lower heating value bigger than or equal to 16MJ / Kg and with an ash dry basic smaller than or equalto 40% being dried and milled by an intermediate-speed coal mill until the mesh number is smaller or equal to 100 and the moisture content is smaller or equal to 0.5%, pre-heating the pulverized coalto the temperature of 80 DEG C - 150 DEG C, transferring the pulverized coal to an air-fluidized bed gas generator,mixing the water vapour and the air in proportion, the high-temperature coal gas produced by the air-fluidized bed gas generator passing through a hot precipitator, directly spraying the coal gas after that 90%-95% dust of the coal gas has been eliminated to the lower part of the shaft furnace, the upper part of a material-discharging roller participating in the reduction reaction in the shaft furnace, reducing the iron or other metallic oxide into metallized pellets.The invention has a high reduction temperature, a high reduction speed, a high exhaust physical heat and a chemical heat which is 1.5 times higher than that of the blast furnace gas, reductive cost is greatly reduced by using the middle coal with a low heating value and a high fugitive constituent as the reductive, therefore, the per-ton cost of the generated energy sources of electrical energy, coal gas and the like is lower than 1500 yuan / t.

The invention relates to a one-step solid desulfurizing agent used for removal of low carbon olefins from sulfur-containing compounds and a preparation method thereof, and mainly solves the problems that desulfurization methods in the prior art are low in selectivity, low in breakthrough sulfur capacity, low in desulfurization rate and the like. The one-step solid desulfurizing agent is a high activity Ni based desulfurizing agent which comprises the following components by weight: a) 10.0-50.0% of NiO, b) 10.0-50.0% of ZnO, c) 1-25% of an oxide of at least one element selected from group IIVB in the periodic table of elements, d) 2.0-20.0% of an oxide of at least one element selected from group IIA in the periodic table of elements, and e) 10.0-50.0% of Al2O3. By adopting the technical scheme and the preparation method, the problems that desulfurization methods in the prior art are low in selectivity, low in breakthrough sulfur capacity, low in desulfurization rate and the like can be well solved, and the one-step solid desulfurizing agent can be used in the desulfurization process for propylene, butylenes and other low carbon olefin chemical raw materials.

A method for preparing ultra-fine iron powder through double reduction of low-temperature hydrocarbons, step 1, ball milling iron ore concentrate powder, carbon powder and catalyst with a certain purity; The ratio is evenly mixed; step 3, the material after mixing is placed under a protective atmosphere for heating and reduction, and primary reduced iron is obtained after cooling; step 4, the primary reduced iron described in step 3 is ball milled; step 5, the primary reduced iron in step 4 is The primary reduced iron after ball milling is placed in a hydrogen atmosphere for final reduction, cooled and released from the furnace to obtain reduced iron powder; step 6, ball milling the reduced iron powder described in step 5 to obtain superfine iron powder. Compared with the prior art, the present invention has the advantages of low reaction temperature, low energy consumption, and low hydrogen consumption, and is easy to obtain high-quality ultrafine iron powder, and has simple preparation process, low energy consumption, and low production cost.