117results about How to "Low S content" patented technology

The invention relates to austenite stainless steel and a production method thereof, and belongs to the technical field of stainless steel processing. The stainless steel product mainly comprises the following chemical components in percentage by weight: less than or equal to 0.03 percent of C, 0.4-0.6 percent of Si, 1.0-1.5 percent of Mn, 16.5-18.0 percent of Cr, 10.0-11.0 percent of Ni, 0.010-0.050 percent of N, 2.00-2.50 percent of Mo, less than or equal to 0.040 percent of P, less than or equal to 0.003 percent of S, 20-40ppm of B and the balance of Fe and inevitable impure elements, wherein the DG value is between 6 and 9, the value of Md30 is 30DEG C below zero- 60 DEG C below zero. The production process comprises the following steps: intensively deoxidizing and desulfurizing, adding Fe-B to refine the grain size of an as-cast billet, adding Ca-Si wires into a ladle furnace (LF) and prolonging the time of soft blowing and standing, controlling the superheat degree to be 20-40 DEG C and constant pulling speed of 1.1-1.15m/min; and weakening secondary cooling water, performing hot rolling, cold rolling and thermal treatment, and pickling. By adopting the method, the problem of surface defects occurring in the stainless steel processing process can be alleviated, and the cold rolling yield can be increased.

The invention provides a nickel-cobalt-manganese core-shell structure precursor and a preparation method thereof. The precursor is compact in inner core and has pores; the shell is loose, and the primary particles are radially arranged on the inner core. The precursor structure is beneficial to diffusion of Li ions and permeation of an electrolyte in the lithium mixing and sintering process, provides a rapid migration channel for the Li ions in the charging and discharging process, and meets the structural requirements of tap density and porosity. The precursor is synthesized by adopting a wetmethod, the reaction process is divided into a first stage and a second stage, the switching point of the first stage and the second stage is determined according to the size requirement of the innercore part of the precursor, and the reaction conditions are adjusted. The preparation method is simple in process control, free of newly increased cost, wide in process application range, good in product crystallinity, low in impurity Na and S content and adjustable in precursor kernel size on the basis of an existing mainstream intermittent method process.

The invention relates to a method for preparing a low-sulfur ternary precursor, relating to lithium-ion anode materials. The method for preparing the low-sulfur ternary precursor, provided by the invention, is efficient, simple and convenient, and the sulfur content of the ternary precursor can be reduced through controlling a precipitation stage and an after-treatment method and is reduced to 2,000ppm so as to meet the requirements of lithium-ion batteries for ternary materials. The method comprises the steps of: (1) simultaneously introducing three solutions, namely ternary material liquid, a sodium hydroxide solution and ammonia water, into a reaction kettle, stirring, and carrying out chemical crystallization so as to obtain a ternary precursor; (2) filtering the ternary precursor obtained in the step (1) so as to remove mother liquor, then, conveying the ternary precursor into a turbine-stirring alkaline cleaning tank, carrying out water-bath heating, stirring and then filtering; (3) washing a product obtained after alkaline cleaning by using a plate and frame filter until the conductivity of the washed water is not higher than 20 us/cm; and (4) quickly drying a washed qualified material by a rotary kiln, and sieving to obtain the low-sulfur ternary precursor, wherein the S impurity content of the obtained low-sulfur ternary precursor is not higher than 2,000ppm.

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 discloses a preparation method of high-quality 40Cr alloy structure straight-bar round steel. The preparation method includes the following steps, namely, the step A of molten iron pretreatment and desulfuration, the step B of molten iron smelting, the step C of deoxidization alloying, the step D of molten iron LF furnace refining, the step E of molten iron VD furnace vacuum refining, the step F of molten iron casting, the step G of steel billet heating, the step H of rolling and the step I of steel finishing. The high-quality 40Cr alloy structure straight-bar round steel produced through the method is high in cleanliness and low in inclusion content and content of harmful elements P and S, has high strength, excellent ductility and toughness, excellent impact toughness and excellent upsetting deformation capacity, and can well meet the requirements of the field of high-end machine manufacturing industries.

The invention provides a preparation method of a ternary cathode material precursor. The preparation method comprises the following steps: (1) co-precipitation: using pure water to prepare a mixed metal ion solution of soluble nickel salts, manganese salts, and cobalt salts, mixing the mixed metal ion solution with an alkali metal hydroxide solution and an ammonium salt solution; after precipitation, separating solids and liquid, and blowing the solids to obtain a first nickel-manganese-cobalt hydroxide material; and (2) primary drying: drying the first nickel-manganese-cobalt hydroxide material obtained in the step (1) in vacuum to obtain the primarily dried ternary cathode material precursor. The ternary cathode material precursor prepared by the provided preparation method has the following physical and chemical indexes: the particle distribution span is not more than 1.2; D50 is 9 to 12 [mu]m; and the tap density is not less than 2.40 g/cm3. The preparation method has the advantages that the operation is simple, the particle distribution of prepared ternary cathode material precursor is uniform, the tap density is high, impurities can be removed easily, and the method is practical.

The invention belongs to the technical field of ferrous metallurgy, and discloses a corrosion-resistant steel plate for an ocean platform and a production method of the steel plate. The corrosion-resistant steel plate is prepared firstly from the combination of proper components in percentage by weight and then by carrying out KR molten iron pretreatment, converter smelting, argon-blowing station fed with aluminum wire, LF furnace refining, VD vacuum refining, continuous casting, heating, controlled rolling and controlled cooling, heap cooling, quenching, tempering and the like. According to the corrosion-resistant steel plate for the ocean platform and the production method of the steel plate, compared with the prior art, the produced steel plate has the advantages of excellent corrosion resistance, good low-temperature impact toughness and excellent comprehensive performance, and is especially suitable for being used under cold weather and seawater corrosion conditions.

The invention provides a production method of a composite material stirring wing. The method comprises the following steps of: (1) wax pressing process; (2) shell making process; (3) dewaxing process; (4) roasting process; (5) composite material smelting process; (6) clean sand pouring process; (7) sprue removing and cleaning process; and (8) heat treatment process. The production method can be used for producing the stirring wing with high safety and reliability, and the high-quality composite material stirring wing can be produced by the method.

The invention discloses a method for re-concentrating vanadium-titanium magnetite concentrate through alkaline leaching, acid pickling and magnetic separation. The method comprises the following steps: placing the vanadium-titanium magnetite concentrate in an alkali solution of which the mass concentration is 5-52% to be subjected to alkaline leaching reaction at the temperature of 280-370 DEG C for 0.5-5 hours, and filtering to obtain a filtrate and an alkaline leached filter cake A; preparing the filter cake A into ore pulp by adding water according to the fact that the mass ratio of solid to liquid is 1:(1-10), placing the ore pulp into an H2SO4 solution of which the mass concentration is 1-10% to be subjected to acid pickling at the temperature of 50-90 DEG C for 5-60 minutes, and filtering to obtain a filtrate and an acid picked filter cake B; preparing the filter cake B into ore pulp of which the mass concentration is 30-35% by adding water to be subjected to magnetic separation, so as to obtain iron ore concentrate of which the TFe content is 64-68% and titanium concentrate of which the TiO2 content is 40-60%. The method has the advantages that the vanadium-titanium magnetite concentrate can be efficiently sorted, the alkali consumption is low, the content of impurities such as Al and Si entering a blast furnace, especially the content of detrimental impurities such as TiO2 and S, is reduced, the utilization coefficient of the blast furnace is increased, the iron-making cost is reduced, the problem of high S content in the smelting process is solved, and the comprehensive utilization ratio of a titanium resource is increased at the same time.

The invention provides a method of extracting and separating crude oil. The method comprises the step of extracting the crude oil by adopting a selective solvent, wherein the selective solvent comprises a polar non-proton solvent. According to a polarity effect and hydrogen-bond interaction, the crude oil is divided into polar and nonpolar two components. During solvent separation, an inorganic salt component in the crude oil is enriched, and corrosion of Cl to equipment is reduced. A demulsifier can be added into the solvent extraction process so that moisture in the crude oil can be removed through the solvent better. While the crude oil is separated, the content of S, N and metal in a light component can be reduced at the same time, and the processing pressure of subsequent devices is reduced. According to the method of extracting and separating the crude oil, not only is energy consumption far lower than that of distillation, but also coking, polymerization or dissociation of heavy distillates of petroleum in the process can be avoided, a high-vacuum apparatus during reduced pressure distillation is not needed either, and the operation cost and equipment cost are remarkably reduced.

The invention discloses a preparation and treatment method for low-sulfur manganese cobalt nickel hydroxide. According to the method, the crystallization degree of a product is increased by controlling parameters including a pH value and the like in a synthetic process, impurities in a crystal structure are reduced, and the effect of reducing the S content of the product is achieved in a mode of combining special alkali liquor elution with water washing. The S content of a prepared material is low and reaches 0.1%, so that a positive electrode material prepared from a precursor has excellent electrochemical performance.

The invention provides a method for manufacturing a Ni steel moderately-thick plate for a low-temperature container. The Ni steel moderately-thick plate comprises, by weight, 0.03-0.07% of C, 0.10-0.25% of Si, 0.50-0.90% of Mn, 0-0.005% of S, 0-0.008% of P, 3.25-3.75% of Ni, 0.02-0.05% of Alt and the balance Fe. The method comprises the steps that a continuous casting billet is heated to 1150-1200 DEG C, two-stage controlled rolling is conducted after heat preservation is conducted for one to two hours, the rough rolling start temperature is 1030-1100 DEG C, and the finish rolling temperature is 800-870 DEG C; laminar cooling is conducted after rolling, and the red return temperature is 630-700 DEG C. A quenching and tempering heat treatment process is adopted; the quenching temperature is 820-870 DEG C, and the heat preservation time is 30-70 minutes; the tempering temperature is 580-620 DEG C, and the heat preservation time is 30-80 minutes; air cooling is conducted after tempering. According to the method, the alloy components are simple; the steel plate has good matching for strength and toughness, is suitable for manufacturing liquefied petroleum gas (LPG) storage tanks and further can replace 5Ni steel for manufacturing storage tanks for liquefied ethylene gas (LEG) and the like.

The invention discloses a preparation method of flaky iron phosphate, the prepared flaky iron phosphate and application of the flaky iron phosphate. The preparation method comprises the following steps: 1, preparing a ferrite solution, adding phosphoric acid, and adding an oxidant to oxidize ferrous ions into iron ions; 2, preparing a mixed solution from phosphoric acid and sodium hydroxide; 3, heating the mixed solution to 90-100 DEG C, and adding an iron ion solution; and 4, calcining the prepared product to obtain the flaky iron phosphate. In the method, feeding is performed at high temperature, so that almost no yellow intermediate is generated in the feeding process, and a white flaky iron phosphate product is rapidly formed in the feeding process; the process avoids the traditional process of adding a phosphorus salt into an iron salt to generate a yellow intermediate and then gradually turn the yellow intermediate into white. The flaky iron phosphate prepared by the scheme provided by the invention is higher in grinding efficiency and lower in sulfur content; therefore, when the method is applied to the preparation process of lithium iron phosphate, higher battery capacity can be obtained.

The invention relates to a preparation method for a wire rod for a welding wire, in particular to a preparation method for an H08MnA no-twist controlled-cooling hot-rolled wire rod for a submerged-arc welding wire. According to the technical scheme adopted by the invention, the preparation method for the H08MnA no-twist controlled-cooling hot-rolled wire rod for the submerged-arc welding wire is characterized in that the wire rod consists of the following chemical components in proportion: 0.045-0.095% of C, 0.88-1.02% of Mn, 0.035-0.065% of Si, less than or equal to 0.009% of P, less than or equal to 0.009% of S and the balance of Fe; the wire rod is rolled through a no-twist high-speed wire rolling mill, and then is cooled by a delay type Stelmor process after being rolled. According to the preparation method for the H08MnA no-twist controlled-cooling hot-rolled wire rod for the submerged-arc welding wire provided by the invention, product metallurgical quality, chemical components and drawing properties are guaranteed to meet usage needs.

The invention discloses a method for recleaning vanadium titanium magnetite concentrate by using alkaline leaching and desliming. The method comprises the following steps: placing vanadium titanium magnetite concentrate into an alkaline solution with the mass concentration of 5-52%, performing alkaline leaching reaction for 0.5-5 hours at the temperature of 260-370 DEG C, and filtering to obtain a filtrate and an alkaline-leached filter cake A; adding water to the A to prepare A to ore slurry with the mass concentration of 21-15 % for performing desliming operation so as to obtain a sand setting B and an overflow C, wherein the sand setting B is a final iron concentrate with the TFe content of 60-68%, and the overflow C is a final titanium concentrate with the TiO2 content of 40-50%. The method has the advantages that the efficient separating of the vanadium titanium magnetite concentrate is realized; the alkali consumption is low; the contents of impurities such as Al and entering a blast furnace can be reduced, in particular the contents of harmful impurities such as TiO2 and S; the blast furnace utilization coefficient is increased; the blast furnace slag discharge capacity is reduced; the ironmaking cost is reduced; the problems of high S content and serious pollution in the smelting process can be solved; meanwhile, the comprehensive utilization of a titanium resource is improved.

The invention discloses a sulfur-containing and bismuth-containing free cutting stainless steel. The sulfur-containing and bismuth-containing free cutting stainless steel comprises less than or equalto 0.08% of C, 0.5-1.0% of Si, 2.0-3.0% of Mn, less than or equal to 0.06% of P, 0.20-0.35% of S, 8.5-1.0% of Ni, 17.0-19.0% of Cr, 2.0-3.0% of Cu, 0.02-0.2% of Bi, less than or equal to 0.07% of N and the balance of iron and inevitable impurities according to the weight percentage. The invention further discloses a preparation method of the sulfur-containing and bismuth-containing free cutting stainless steel. According to the sulfur-containing and bismuth-containing free cutting stainless steel, by using a method of adding a bismuth element, the cutting performance of a material is improved;by reducing the sulfur content and using an intermediate slab online heating and dry head rolling technology during rolling, a problem that the hot-working character becomes poor due to the adding ofbismuth is solved; solid solution adopts 1050 degrees centigrade complete solid solution process; before acid pickling of a steel wire rod, a problem that the acid pickling surface is easy to be superacid after high temperature treatment is solved through salt bath treatment.

The invention discloses a method for inhibiting low-sulfur steel from being subjected to refinement and resulfurization in an LF furnace. The method comprises the following steps of, desulfurizing molten iron of a steel grade with S content not more than 0.03 wt%; smelting in a converter; refining in an LF furnace; carrying out pouring and subsequent procedures, wherein the time from the end of molten steel pouring to the beginning of pouring refining slag out of a molten steel tank is controlled to be not more than 13 min; and Then loading the smelted low-sulfur molten steel into the molten steel tank, and carrying out conventional refining and subsequent procedures on the sulfur molten steel in the LF furnace. According to the method, by smelting steel with S content not more than 0.03 wt% in one furnace and controlling the alkalinity of the refining slag in the LF furnace to be less than or equal to 1.2 and the sulfur content in the refining slag to be not more than 0.2 wt%, so that the content of sulfur attached in the molten steel tank is reduced; and after the low-sulfur molten steel to be refined is filled into the molten steel tank, the resulfurization of the low-sulfur steel subjected to LF refining is stabilized to be less than or equal to 0.001 wt%, the judgment-changing rate of the low-sulfur steel is reduced to 1.25% from the original 15.78%, and steel material consumption (molten iron slagging-off) is reduced by 2-3 kg/t.

The invention discloses a method for recleaning of vanadium-titanium magnetite concentrates by utilizing alkaline leaching, desliming and magnetic-gravity combined separation. The method comprises the following steps of placing the vanadium-titanium magnetite concentrates into aqueous alkali with the mass concentration of 5-52%, carrying out alkaline leaching reaction at 280-370 DEG C for 0.5-5 hours and filtering to obtain filtrate and an alkaline leaching filter cake A; adding water to the A to prepare pulp with the mass concentration of 21-25% to carry out desliming operation so as to obtain sunk sand B and overflow C; adding water to the B to prepare pulp with the mass concentration of 30-41% to carry out magnetic-gravity combined recleaning so as to obtain iron ore concentrates with the TFe content of 63-68% and titanium ore concentrates with the TiO2 content of 50-70% respectively. The method has the advantages that the vanadium-titanium magnetite concentrates are effectively sorted, the alkali consumption is low, the content of impurities, such as Al and Si, in a blast furnace, in particular the content of detrimental impurities TiO2 and S, is reduced, the utilization coefficient of the blast furnace is increased, the discharge of the blast furnace slag is reduced, the iron making cost is reduced, the problems of high content of S and serious pollution in a smelting process are solved, and meanwhile, the comprehensive utilization rate of titanium resources is improved.

The invention relates to a vanadium-titanium magnetite concentrate re-concentration method achieved through oxidation alkaline leaching, acid pickling, desliming and gravity and magnetism. The method is characterized by including the following steps that oxidation alkaline leaching is performed on vanadium-titanium magnetite concentrate, and the vanadium-titanium magnetite concentrate is placed in an alkaline solution; oxidization agents are added; then, an alkaline leaching reaction lasts for 0.5-2 h at the temperature of 220-330 DEG C; filtration is performed, and then filter liquor and alkaline leached filter cakes A are obtained; water is added in the alkaline leached filter cakes A, and ore pulp is prepared; then, the ore pulp is placed in a H2SO4 solution, and acid pickling is performed for 5-60 min at the temperature of 50-90 DEG C; filtration is performed, and filter liquor and acid leached filter cakes B are obtained; water is added into B, and ore pulp with the mass concentration being 30-35% can be prepared; and desliming and gravity and magnetism combined re-concentration is performed, and iron concentrate with the TFe content being 64-70% and titanium concentrate with the TiO2 content being 60-82% can be obtained respectively. The method has the beneficial effects that due to introduction of O2 or H2O2 during oxidation alkaline leaching, S compounds can be oxidized, the reaction is accelerated, the reaction temperature is lowered, the reaction time is shortened, and energy consumption and equipment investment are greatly reduced.

The invention discloses a method for recleaning vanadium titanium magnetite concentrate by using alkaline leaching, pickling and reverse flotation. The method comprises the following steps: putting vanadium titanium magnetite concentrate into an alkaline solution of which the mass concentration is 5-52%; carrying out alkali leaching reaction at 280-370 DEG C for 0.5-5 hours; filtering to obtain filtrate and an alkali leaching filter cake A; adding water to A to prepare ore pulp of which the solid-liquid mass ratio is 1:(1-10), putting into an H2SO4 solution of which the mass concentration is 1-10%, picking at 50-90 DEG C for 5-60 minutes, and filtering to obtain filtrate and a pickling filter cake B; adding water to B to prepare ore pulp of which the mass concentration is 25-30%, carrying out reverse flotation, so as to respectively obtain iron ore concentrate of which the TFe content is 65-69.5% and titanium concentrate of which the TiO2 content is 40-80%. The method has the advantages that the vanadium titanium magnetite concentrate is efficiently sorted, the alkali consumption is low, such impurities entering a blast furnace as such as Al, Si, especially TiO2 and S, are reduced, the utilization coefficient of the blast furnace is improved, the discharge of blast furnace slag is reduced, the ironmaking cost is reduced, and meanwhile, the comprehensive utilization rate of titanium resources is improved.