The production method of VN alloy
Technical field
The invention belongs to technical field of ferrous metallurgy, relate to a kind of production method of VN alloy of steel-making additive.
Background technology
VN alloy is a kind of steel-making additive, VN alloy is added the mechanical propertys such as intensity, toughness, ductility and thermal fatigue resistance that can improve steel in steel to, simultaneously can give steel good solderability, so Iron and Steel Production increase day by day to the demand of high-quality VN alloy.At present, report about vanadium nitrogen alloy preparation method is a lot, such as vacuum method, normal pressure nitriding etc., and produce the higher level that all reached, but all there are the problems such as output is lower, quality is unstable in it,, in order to improve the Quality and yield of VN alloy, be badly in need of a kind of production method of VN alloy of high-quality economy in industry.
Chinese patent CN101289713A discloses a kind of production method of VN alloy, be Vanadium Pentoxide in FLAKES is levigate after, make globe after adding iron powder, carbon dust, binding agent to mix, globe is delivered to horizontal pushed bat kiln, pass into nitrogen in pushed bat kiln, keep pressure-fired in kiln, carry out carbonization and nitrogenizing reaction, carbonation reaction temperature is 1350-1500 ℃, reaction times 2-3.5 hour, nitriding temperature is 1000-1150 ℃, and reaction times 0.5-1.5 hour progressively is cooled to below 100 ℃ and comes out of the stove.Vacuum unit is not used in this invention, simplified flow process, reduced facility investment, but carbonization and nitrogenizing reaction temperature requirement are high, power consumption is large, generally can contain simultaneously the impurity such as sulphur phosphorus in iron powder, well-known, the sulphur phosphorus impurities can increase iron and steel fragility, destroy the performances such as ductility, toughness, affected the VN alloy quality, the utilization ratio of this invention vanadium is lower, and production cost is high.
Summary of the invention
The invention provides a kind of production method of VN alloy, the vanadium utilization ratio that exists with the solution prior art is low, power consumption is large and can't go deimpurity problem.
The technical solution adopted for the present invention to solve the technical problems is to add lime, ammonium nitrate and aqueous glycol solution in levigate vanadium pentoxide powder, use carbon dioxide to purge the spherical surface of making after mixing dry, its concrete steps are as follows:
(1) levigate: as in ball mill, the raw material Vanadium Pentoxide in FLAKES to be finely ground to powder;
(2) batch mixing: add carbon dust, lime, reaction promotor ammonium nitrate in the vanadium pentoxide powder that obtains to step (1), after stirring, add again the binding agent aqueous glycol solution, make globe, wherein the carbon dust add-on is the 19-25% of Vanadium Pentoxide in FLAKES quality, lime adding amount is the 0.5-2% of Vanadium Pentoxide in FLAKES quality, the ammonium nitrate add-on is the 2-5% of Vanadium Pentoxide in FLAKES quality, binding agent is the aqueous glycol solution that contains 3-5%, and the binding agent add-on is the 13-19% of Vanadium Pentoxide in FLAKES quality;
(3) drying: the spherical surface of making to step (2) purges carbon dioxide, and carbon dioxide gas pressure is controlled in 2kgf, and flow control is at 2Nm
3/ h, purge time were controlled in 1 hour;
(4) reaction: globe is delivered in the baking oven that is full of nitrogen and carried out carburizing reagent, the about 600-800 ℃ of carbonation reaction temperature, be incubated about 4 hours; Then globe is gone in rotary kiln and carry out nitrogenizing reaction, the nitrogenizing reaction temperature is controlled at 500-600 ℃, and passes into nitrogen continuously in kiln, keeps pressure-fired, about 6 hours of time in kiln;
(5) cooling discharging: be cooled in 100 ℃, obtain the finished product VN alloy.
The volumetric concentration of the carbon dioxide that passes in above-mentioned drying step is 99.99%.
The preferred 720 ℃ of left and right of carbonation reaction temperature in above-mentioned reactions steps; The preferred 560 ℃ of left and right of nitrogenizing reaction temperature.
By add lime in Vanadium Pentoxide in FLAKES, lime is that sulphur phosphorus removes agent, lime is calcium oxide, calcium oxide can with nickel powder in sulphur and phosphoric reaction, calcium oxide and phosphorus reaction generate calcium phosphate, calcium oxide and reaction of Salmon-Saxl generate sulfurated lime, can effectively the sulphur phosphorus impurities that contains in various raw materials be removed; Ammonium nitrate is reaction promotor, and ammonium nitrate can form complex compound with carbon or vanadium, accelerates carbonization and the nitrogenizing reaction of Vanadium Pentoxide in FLAKES, and carbonization and nitrogenizing reaction are carried out at lower temperature; Aqueous glycol solution can make the meals such as Vanadium Pentoxide in FLAKES, carbon dust effectively bonding.
Compared with prior art, beneficial effect of the present invention is:
By adding desulfurization phosphorus agent lime, reaction promotor ammonium nitrate and tackiness agent aqueous glycol solution, reaction is carried out at lower temperature, the power consumption of VN alloy production process reduces greatly; Sulphur phosphorus in desulfurization phosphorus agent lime white raw material removes, and has improved the final product quality of VN alloy; This processing method has improved the vanadium utilization ratio, can reach more than 70%.
Embodiment
The present invention is further described below in conjunction with specific embodiment.
(1) levigate: as in ball mill, the raw material Vanadium Pentoxide in FLAKES to be finely ground to powder;
(2) batch mixing: add carbon dust, lime, reaction promotor ammonium nitrate in the vanadium pentoxide powder that obtains to step (1), after stirring, add again the binding agent aqueous glycol solution, make globe, the carbon dust add-on is 21% of Vanadium Pentoxide in FLAKES quality, and lime adding amount is 1% of Vanadium Pentoxide in FLAKES quality, and the ammonium nitrate add-on is 3% of Vanadium Pentoxide in FLAKES quality, binding agent is to contain 4% aqueous glycol solution, and the binding agent add-on is 15% of Vanadium Pentoxide in FLAKES quality;
(3) drying: the carbon dioxide of the spherical surface purge volume concentration 99.99% of making to step (2), carbon dioxide gas pressure is controlled at 1kgf, and flow control is at 2Nm
3/ h, purge time are 45 minutes;
(4) reaction: globe is delivered in the baking oven that is full of nitrogen and carried out carburizing reagent, about 720 ℃ of temperature of reaction, be incubated about 4 hours; Then globe is gone in rotary kiln and carry out nitrogenizing reaction, temperature of reaction is controlled at 560 ℃, and passes into nitrogen continuously in kiln, keeps pressure-fired, about 6 hours of time in kiln;
(5) cooling discharging: be cooled in 100 ℃, obtain the finished product VN alloy.
Finished product VN alloy apparent density is 3.2g/cm
3, content of vanadium is 77.4%, and nitrogen content is 16.8%, and the vanadium utilization ratio reaches 72%.