Preparation method for directly synthesizing vanadium-nitrogen alloy by adopting vanadium slag
阅读说明：本技术 一种采用钒渣直接合成钒氮合金的制备方法 (Preparation method for directly synthesizing vanadium-nitrogen alloy by adopting vanadium slag ) 是由 朱万政 田博 高波 于海阔 高子齐 袁玉涛 刘翠花 于 2020-06-10 设计创作，主要内容包括：一种采用钒渣直接合成钒氮合金的制备方法,其步骤为：(1)准备原料；(2)原料混合；(3)生球制备；(4)推板窑内合成。本发明采用钒渣直接制备钒氮合金,严格控制配比混合制成球状物,合理的原料粒度及配碳量,然后利用碳热还原渗氮一步法生产钒氮合金。(A preparation method for directly synthesizing vanadium-nitrogen alloy by adopting vanadium slag comprises the following steps: (1) preparing raw materials; (2) mixing the raw materials; (3) preparing green balls; (4) synthesized in a pushed slab kiln. The invention adopts vanadium slag to directly prepare vanadium-nitrogen alloy, strictly controls the proportion and mixes to prepare balls, has reasonable raw material granularity and carbon content, and then utilizes a carbon thermal reduction nitriding one-step method to produce the vanadium-nitrogen alloy.)
1. A preparation method for directly synthesizing vanadium-nitrogen alloy by adopting vanadium slag is characterized by comprising the following steps:
(1) preparing raw materials: selecting a vanadium slag raw material with the grade of 21, preparing a carbon reducing agent, grinding the vanadium slag by using a pendulum type grinding machine, sieving by using a 140-mesh sieve after grinding, and collecting vanadium slag particles with the particle size smaller than the 140-mesh sieve;
(2) mixing raw materials: firstly, carrying out dry mixing on vanadium slag and a carbon reducing agent by adopting a rotary dry mixer, uniformly mixing in a dry manner, transferring into a wet mixer, and adding a binder into the wet mixer to carry out wet mixing for 30-60 min;
(3) preparing green balls: transferring the wet mixed material into a ball press machine, pressing wet material balls by using a powerful ball press machine, cooling and solidifying the wet material balls, and drying the green balls in a tunnel type drying kiln to obtain dry material balls, wherein the drying temperature is 150-180 ℃, and the drying time is 48 hours;
(4) synthesis in a pushed slab kiln: and (3) adopting a high-temperature nitrogen protection pushed slab kiln to finish the continuous normal-pressure sintering of the vanadium-nitrogen alloy, adopting a nitrogen evacuation method to replace a vacuum environment, ensuring the atmosphere requirement, raising the temperature of the kiln to 1250 ℃, preserving the heat for 2h, raising the temperature to 1450 ℃, preserving the heat for 4h, and then reducing the temperature to below 100 ℃ to obtain the vanadium-nitrogen alloy.
2. The method for preparing vanadium-nitrogen alloy directly synthesized from vanadium slag according to claim 1, wherein the carbon reducing agent is carbon powder or graphite.
3. The method for preparing the vanadium-nitrogen alloy by directly synthesizing the vanadium slag according to the claim 1, wherein the ratio of the vanadium slag to the reducing agent during the dry mixing is 100: 25 to 33.
4. The method for preparing vanadium-nitrogen alloy directly synthesized by vanadium slag according to claim 1, wherein the wet mixer is a planetary wheel mill mixer.
5. The method for preparing the vanadium-nitrogen alloy by directly synthesizing vanadium slag according to claim 1, wherein the binder is a polyvinyl alcohol solution with the concentration of 2-4%.
6. The preparation method for directly synthesizing the vanadium-nitrogen alloy by adopting the vanadium slag as claimed in claim 1, wherein the mass ratio of the vanadium slag particles added in the wet mixing process to the binder is 100: 5-13.
7. The method for preparing vanadium-nitrogen alloy directly synthesized from vanadium slag according to claim 1, wherein the silicon carbide rod and the silicon molybdenum rod are selected as heating elements in the step (4).
Technical Field
The invention relates to the technical field of vanadium-nitrogen alloys, in particular to a preparation method for directly synthesizing a vanadium-nitrogen alloy by adopting vanadium slag.
Background
Vanadium is an important alloy element in steel production, the application range of vanadium-nitrogen alloy is continuously expanded along with the rapid development of converter smelting strength microalloyed steel production technology, and purified V is generally adopted in the process of preparing vanadium nitride from vanadium oxide2O5Preparation of vanadium-nitrogenThe discovery that vanadium slag is slag containing vanadium oxide obtained by oxidizing and blowing vanadium-containing molten iron in the vanadium extraction process or vanadium-containing iron concentrate obtained by wet vanadium extraction, and is a raw material for smelting and preparing vanadium alloy and metal vanadium is rare that vanadium slag contains V2O5Are divided into 6 marks V2O5The grade with the content of more than 20 percent is vanadium slag 21, wherein P, CaO and SiO are contained in the vanadium slag2And the content of Fe is limited, impurities which are not contained with vanadium in the vanadium slag can influence the preparation of the vanadium-nitrogen alloy, and influence the yield or quality of the generated vanadium-nitrogen alloy.
Disclosure of Invention
The invention provides a preparation method for synthesizing vanadium-nitrogen alloy by directly taking vanadium slag as a raw material to solve the problems.
The technical scheme adopted by the invention is as follows:
a preparation method for directly synthesizing vanadium-nitrogen alloy by adopting vanadium slag comprises the following steps:
(1) preparing raw materials: selecting a vanadium slag raw material with the grade of 21, preparing a carbon reducing agent, grinding the vanadium slag by using a pendulum type grinding machine, sieving by using a 140-mesh sieve after grinding, and collecting vanadium slag particles with the particle size smaller than the 140-mesh sieve;
(2) mixing raw materials: firstly, carrying out dry mixing on vanadium slag and a carbon reducing agent by adopting a rotary dry mixer, uniformly mixing in a dry manner, transferring into a wet mixer, and adding a binder into the wet mixer to carry out wet mixing for 30-60 min;
(3) preparing green balls: transferring the wet mixed material into a ball press machine, pressing wet material balls by using a powerful ball press machine, cooling and solidifying the wet material balls, and drying the green balls in a tunnel type drying kiln to obtain dry material balls, wherein the drying temperature is 150-180 ℃, and the drying time is 48 hours;
(4) synthesis in a pushed slab kiln: and (3) adopting a high-temperature nitrogen protection pushed slab kiln to finish the continuous normal-pressure sintering of the vanadium-nitrogen alloy, adopting a nitrogen evacuation method to replace a vacuum environment, ensuring the atmosphere requirement, raising the temperature of the kiln to 1250 ℃, preserving the heat for 2h, raising the temperature to 1450 ℃, preserving the heat for 4h, and then reducing the temperature to below 100 ℃ to obtain the vanadium-nitrogen alloy.
The carbon reducing agent is carbon powder or graphite.
The ratio of the vanadium slag to the reducing agent during dry mixing is 100: 25 to 33.
The wet mixer is a planetary wheel-grinding mixer.
The binder is 2-4% of polyvinyl alcohol solution.
The mass ratio of the vanadium slag particles added in the wet mixing process to the binder is 100: 5-13.
In the step (4), a silicon-carbon rod and a silicon-molybdenum rod are selected as heating elements, because the vanadium slag contains Na2O、K2Strong alkaline substances such as O and the like can generate a large amount of strong alkaline corrosive media in the sintering process, and a silicon-carbon rod and a silicon-molybdenum rod are used as heating elements, and the service life of the heating elements is ensured by adopting a gas isolation method.
The invention has the beneficial effects that: the invention adopts vanadium slag to directly prepare vanadium-nitrogen alloy, strictly controls the proportion and mixes to prepare balls, has reasonable raw material granularity and carbon content, and then utilizes a carbon thermal reduction nitriding one-step method to produce the vanadium-nitrogen alloy.
Detailed Description
A preparation method for directly synthesizing vanadium-nitrogen alloy by adopting vanadium slag comprises the following steps:
(1) preparing raw materials: selecting a vanadium slag raw material with the grade of 21, wherein the vanadium content is more than 20%, preparing a carbon reducing agent, wherein the carbon reducing agent is carbon powder, grinding the vanadium slag by using a pendulum type grinding machine, sieving the vanadium slag by using a 140-mesh sieve after grinding, and collecting vanadium slag particles with the particle size of less than 140-mesh sieve;
(2) mixing raw materials: firstly, dry-mixing vanadium slag and a carbon reducing agent by adopting a rotary dry mixer, wherein the ratio of the vanadium slag to the reducing agent is 100: 25-33, uniformly mixing in a dry mode, transferring the mixture into a wet mixer, adding a binder into the wet mixer for wet mixing for 30-60 min, wherein the wet mixer is a planetary wheel-grinding mixer, the binder is a 2-4% polyvinyl alcohol solution, and the mass ratio of vanadium slag particles added in the wet mixing process to the binder is 100: 5-13;
(3) preparing green balls: transferring the wet mixed material into a ball press machine, pressing wet material balls by using a powerful ball press machine, cooling and solidifying the wet material balls, and drying the green balls in a tunnel type drying kiln to obtain dry material balls, wherein the drying temperature is 150-180 ℃, and the drying time is 48 hours;
(4) synthesis in a pushed slab kiln: the continuous sintering of vanadium-nitrogen alloy under normal pressure is completed by adopting a high-temperature nitrogen protection pushed slab kiln, and a silicon-carbon rod and a silicon-molybdenum rod are selected as heating bodies to heat the pushed slab kiln, because Na is contained in vanadium slag2O、K2Strong alkaline substances such as O and the like can generate a large amount of strong alkaline corrosive media in the sintering process, a silicon-carbon rod and a silicon-molybdenum rod are used as heating elements, a gas isolation method is adopted to ensure the service life of the heating elements, a nitrogen evacuation method is adopted to replace a vacuum environment, the requirement of the atmosphere is ensured, the temperature of a kiln is increased to 1250 ℃, the temperature is maintained for 2 hours, the temperature is increased to 1450 ℃, the temperature is maintained for 4 hours, and the temperature is reduced to below 100 ℃ to prepare the vanadium-nitrogen alloy.
The present invention will be described in detail with reference to specific examples.