36results about How to "Meet smelting requirements" patented technology

The invention discloses a smelting method of high-purity and high-nitrogen duplex stainless steel, relating to the technical field of stainless steel smelting. According to the smelting method disclosed by the invention, the high-purity and high-nitrogen duplex stainless steel is smelted through a composite process of molten steel vacuum melting and nitrogen filling refining, and the nitrogen content of the high-nitrogen duplex stainless steel is adjusted by controlling the nitrogen pressure during nitrogen filling and the refining time of nitrogen filling. The high-nitrogen duplex stainless steel comprises the following components in percentage by weight: 20-30 percent of Cr, 5-9 percent of Ni, 2-5 percent of Mo, 0.15-0.50 percent of N and the balance of Fe and inevitable impurities. The nitrogen pressure controlling range during smelting is 0.35-0.70MPa, the melting time is 5-20min, the refining maintaining nitrogen pressure is 0.35-0.70MPa, and the refining time is 10-30min. The smelting method has the advantages that compared with the traditional smelting method, with the adoption of the smelting method, the operation is easy, the nitrogen content in the steel can be accurately adjusted, the production cost is low through smelting under the normal pressure or the negative pressure, and the purity of the smelted steel is higher.

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.

The invention discloses a preparation process of a low-grade laterite nickel ore oxidized pellet. The preparation method comprises the following steps: drying low-grade laterite nickel ore until the moisture content of the laterite nickel ore is 11-13%, and crushing the laterite nickel ore with a double-roll crushing mill until the grain size of the laterite nickel ore is minus 3mm; evenly mixinglaterite nickel ore, iron ore concentrate, chromite and a calcium-containing additive in a mass proportion of (45-50%):(30-35%):15%:(5.0-7.7%); carrying out high-pressure rolling pretreatment on the mixed material; pelletizing on a disk pelletizing machine, wherein the moisture content of fresh pellet is 12-12.5%, and the grain size of the fresh pellet is controlled to 12-16mm; and carrying out drying preheating and roasting on the fresh pellet in a chain gate and a rotary kiln or a belt type roasting machine so as to obtain the finished product oxidized pellet, wherein the preheating temperature is 1000-1100 DEG C, the preheating time is 12-15 minutes, the roasting temperature is 1220-1280 DEG C, and the roasting time is 12-15 minutes. The invention relates to the preparation process of the low-grade laterite nickel ore oxidized pellet with high finished product pellet compression strength and wide roasting temperature range when the laterite nickel ore is used for production of pellets.

The invention discloses an MgCa-SiC-C fireproof material, belonging to the technical field of fireproof materials. The MgCa-SiC-C fireproof material comprises the following components by mass: 50-70% of electrically molten or sintered magnesium-calcium sand or magnesium-domolite sand granule, 10-20% of electrically molten or sintered magnesium sand fine powder, 5-17% of silicon carbonate, 5-15% of graphite, 1-10% of additive, and anhydrous resin bonder accounting for 3-5% of total mass percent of the electrically molten or sintered magnesium-calcium sand or magnesium-domolite sand granule, the electrically molten or sintered magnesium sand fine powder, the silicon carbonate, the graphite and the additive. The invention further discloses a preparation method of the MgCa-SiC-C fireproof material. The MgCa-SiC-C fireproof material can be applied to a high-temperature steel and iron metallurgy container, especially as an inner lining of a hot metal ladle for iron making, and can meet smelting requirements of the preprocessed hot metal ladle.

The invention relates to a calculating model for sintering and burdening. The calculating model is characterized by comprising the following steps: restraining burdening top and bottom limitations as well as chemical component top and bottom limitations and taking iron grade and basicity as a target; adopting a fuzzy theory to establish a fuzzy satisfaction function; in a burdening process, respectively establishing an iron grade satisfaction function and a basicity satisfaction function of sintered ore according to the burdening characteristics and process requirements; re-establishing a penalty function to construct a fitness function; performing algorithm iteration. The calculating model has the advantages of randomly generating a plurality of groups of proportions, calculating an adaptive value of each group of proportions through the fitness function, and comparing to obtain an individual optimal proportion and an overall optimal proportion. Under the guiding of the individual optimal proportion and the overall optimal proportion, each group of proportions is updated to finally obtain the optimal proportion which meets all restraints. The proportion optimization to raw materials is realized, the chemical components and the metallurgical performances are met, and the blast furnace smelting requirements are met.

The invention discloses a pellet with high FeO content. The pellet comprises the following components in percentage by mass: 59-61% of TFe, 21-48% of FeO, 0.27-0.8% of metal Fe, 3.8-4.5% of CaO and 4.3-5.4% of SiO2. The pellet is prepared by the following components in percentage by mass: 91-93% of iron ore concentrate powder, 0-2.0% of inner-coal blending powder, 2-3% of bentonite, and 0-5.5% of outer-rolling coal powder containing 5%-8% of bentonite. The invention further discloses a preparation method of the pellet with high FeO content. The pellet with high FeO content is free from Fe2O3, so that abnormal crystal cracking in the reduction process of transforming Fe2O3 into Fe3O4 is avoided, and the strength is high after the reduction.

The invention discloses an environment-friendly silicon dry-type material and a preparation method thereof. The environment-friendly silicon dry-type material comprises the following components in percentage by mass: 13.6-14.4 wt% of quartz sand with the particle size of 3mm, 63.3-65.3 wt% of quartz sand with the particle size of 0.1-3mm, 15.5-16.5 wt% of quartz sand with the particle size of 0.088mm, 4.7-5.3 wt% of anhydrous glucose and 0.6-0.8 wt.% of sodium borate. When the silicon dry-type material is used for smelting plain steel, the utilization ratio can reach 90% or above, thereby greatly saving the consumption of mineral resources. Since the quartz sand is low in price, the cost is only one twentieth of the magnesium dry-type material, thereby greatly lowering the steelmaking cost in the aspect of raw materials. On the premise of lowering the cost, the environment-friendly silicon dry-type material can completely satisfy the smelting requirements for plain steel without lowering the product quality. The anhydrous glucose used as the additive is odorless, tastes sweet, and can not generate any toxic or harmful gas during baking heating, thereby protecting the environment and good health of workers.

The invention discloses a method for matching coke and adding the coke into a furnace in the blast furnace smelting process. The technology of the method comprises the steps that according to the smelting need, the coke is matched according to the high-low sequence of indexes and added into the blast furnace; according to the indexes from high to low, CSR>M10>the average grain size>M40>the ash content>CRI>the sulfur content; the coke is firstly matched according to the indexes of the highest sequence and added into the blast furnace; if the operation state of the blast furnace is good, coke index modification is stopped; if the operation state of the blast furnace is still poor, the coke is matched according to the indexes of the next sequence and added into the blast furnace; and whether the coke is matched according to the indexes of the next sequence or not is judged according to the operation state of the blast furnace till the operation state of the blast furnace is good. According to the method, the technical aim of adding multiple kinds of coke into the furnace at the same time can be achieved, the situation of excessive coke indexes is avoided, and high-quality coking coal resources are saved; and it is guaranteed that the blast furnace stably and smoothly operates, and meanwhile the ironmaking cost is reduced. The method has the beneficial effects of being simple in technology, high in operability and easy to implement.

The invention discloses a method for measuring the roasting temperature of a self-baking electrode of a calcium carbide furnace and controlling slipping of the electrode. The method has the advantages that more than four temperature sensors are mounted at corresponding positions of the electrode, accordingly, the roasting temperature of the electrode is measured in real time, the roasting quality and the speed of the electrode are computed and judged, slipping operation is automatically controlled according to the roasting quality and the speed, the smelting requirement on the length of the electrode is met assuredly, accidents of soft breakage of the electrode and overburning of a coiled iron sheet are stopped, and purposes of improving running efficiency of the calcium carbide furnace, reducing smelting power consumption and enhancing yield are achieved.

The invention discloses an environment-friendly silicious dry-type material, which is characterized by including the following constituents in mass percent: 13.6-14.4% of quartz sands with the particle size of 3mm, 63.3-65.3% of quartz sands with the particle size of 0.3 mm-3mm, 15.5-16.5% of quartz sands with the particle size of 0.088 mm, 4.7-5.3% of anhydrous dextrose and 0.6-0.8% of borax. The silicious dry-type material can be used for smelting ordinary steel, and the use ratio reaches 90% above, so that the consumption of mineral resources is greatly reduced; besides, quartz sands are one kind of the most extensively distributed minerals on the surface of the earth, the market purchasing price of the raw material per ton is 175.00 yuan, and the market purchasing price of magnesite per ton is 1950.00 yuan, so that the cost can be reduced by 1775 yuan per ton with respect to the main raw material, therefore, based on the raw material consumption and price factor, the cost of the silicious dry-type material is only 1/20 of that of the magnesian dry-type material, as a result, the steelmaking cost is greatly reduced with respect to raw material, particularly, the cost is reduced while the smelting requirement of ordinary steel is met without lowering the product quality.

The invention relates to a palletizing method of iron ore powder. A preparation process of an iron ore pellet comprises the following steps of: placing the iron ore powder with different iron contents into a mixing mill according to certain weight percentage (determined according to the iron contents of various powder materials and the requirements for the total iron content of the iron ore pellet), milling in a mixing manner for 1-3 minutes, and then adding organic and inorganic composite binders; then milling in the mixing manner for 5-10 minutes so as to enter a transmission belt to a pellet forming machine; and enabling the formed pellet to enter a low-temperature furnace at a temperature of 100-120 DEG C through the transmission belt for drying for 30-60 minutes and then enter a high-temperature furnace at a temperature of 480-520 DEG C for drying for 30-60 minutes, wherein the intensity of the pellet can reach more than 1800 N so as to meet the requirements for smelting. The palletizing method is easy to realize the flow line large-scale production and has low production cost and wide application value in metallurgy industry.