CN105039637A - Magnesium-bearing cooling agent for extracting vanadium and preparation method of magnesium-bearing cooling agent - Google Patents

Abstract

The invention belongs to the field of iron and steel smelting, and in particular relates to a magnesium-containing coolant used for extracting vanadium in a converter and a preparation method thereof. The magnesium-containing vanadium-extracting coolant is composed of the following components in weight percentage: 5-35% of magnesite, 60-94% of iron oxide scale, and 1-5% of binder; wherein, MgO in magnesite>40wt%, P< 0.05wt%, S<0.02wt%; TFe>63wt%, P<0.02wt%, S<0.03wt% in the iron oxide scale; the binder is at least one of bentonite, cement and diatomaceous earth. The vanadium extraction coolant prepared by the present invention—cold solidified pellets has uniform shape, good strength, high ball forming rate of 85%, contains less P, S, water and other components, and is completely suitable for use as a vanadium extraction coolant requirements. It can not only ensure the cooling intensity required for vanadium extraction, but also effectively reduce the oxidation of molten iron carbon, which is beneficial to the heat source guarantee for subsequent steelmaking.

Description

A kind of magnesium-containing vanadium-extracting coolant and preparation method thereof

technical field

The invention belongs to the field of iron and steel smelting, and in particular relates to a magnesium-containing coolant used for extracting vanadium in a converter and a preparation method thereof.

Background technique

my country is a big country of vanadium-titanium magnetite. Enterprises such as Panzhihua Iron and Steel, Chenggang, Kunming Iron and Steel, and Weiyang Steel all use vanadium-titanium magnetite for smelting. The vanadium content of molten iron smelted from vanadium-titanium magnetite blast furnace is compared with ordinary molten iron High, and vanadium is an important resource, so vanadium must be extracted before molten iron steelmaking to produce vanadium slag. At present, there are many production methods for producing vanadium slag at home and abroad, mainly including the ladle blowing vanadium process in New Zealand, the vanadium extraction process in South Africa, and the converter vanadium extraction process in Russia and China. Other vanadium extraction processes include vanadium-containing steel slag extraction process. Vanadium, stone coal vanadium extraction process, etc. Among them, the converter vanadium extraction process is the best, and the technical and economic indicators are the best.

The production process system of converter vanadium extraction at home and abroad is the continuous improvement of adding coolant + process temperature + blowing time. Vanadium extraction from hot metal is a selective oxidation technology. Vanadium extraction by converter oxygen blowing is an exothermic process. The oxidation of [Si], [Mn], [V], [C] and other elements makes the molten pool heat up rapidly, while the oxidation of [Si] and [Mn] occurs at the time of [V] oxidation. Before, vanadium extraction could not inhibit its reaction, and the conversion temperature of [C] and [V] was around 1385°C, so to obtain high oxidation rate of [V] and [V] yield, vanadium extracting coolant must be added, Control the molten pool temperature to make it close to [C], [V] conversion temperature, achieve the purpose of extracting vanadium and preserving carbon, and reduce [V] to less than 0.05%. The semi-steel temperature at the end of vanadium extraction should not be too high. The vanadium extraction process is dominated by vanadium oxidation in the early stage and vanadium reduction in the later stage, but the vanadium blowing process is dominated by vanadium reduction. Therefore, the method of cooling is to add coolant to lower the temperature of molten iron to an appropriate range. In converter smelting, through the control of blowing time and process temperature, the vanadium in the semi-steel is oxidized to increase the yield.

The cooling of molten iron is the focus of vanadium extraction production in converters. The cooling of molten iron is mainly to add coolant to the molten iron, and the commonly used coolants are: ordinary iron ore, chilled pellets, scrap steel, iron oxide scale and high-grade ore. Panzhihua Iron and Steel Vanadium uses iron oxide scale, iron oxide balls and cold solidified pellets as coolants. After the cooling system is improved, the vanadium slag grade is ≥17.5%, the semi-steel residual vanadium is ≤0.04%, and the vanadium recovery rate is ≥80.0%. Solid pellets are generally produced using iron concentrate powder, iron oxide scale, etc. as raw materials.

The invention patent with the publication number "CN1789435" discloses a coolant for extracting vanadium and controlling calcium from molten iron and a process for extracting vanadium and controlling calcium from molten iron. The chemical composition (wt%) of the coolant for vanadium extraction is: iron oxide scale 56%-60% , iron concentrate powder 30%-40%, binder 5%-10%, the coolant can increase the extraction rate of vanadium and the grade of vanadium slag, and stabilize the calcium oxide content of vanadium slag.

The invention patent with the publication number "CN101338351" discloses a magnesium-containing vanadium-extracting coolant and its preparation method and use method. The coolant uses iron oxide scale or vanadium extraction sludge, vanadium-containing iron concentrate, and binder as raw materials Production, containing 80%-95% iron oxide, 3-6% SiO ₂ , 0.1-0.6% V ₂ O ₅ , 1-3% MgCl ₂ . In this patent, because SiO ₂ , MgCl ₂ and V ₂ O ₅ are added, the cost is higher, and the vanadium extraction coolant also contains TiO ₂ , Cr ₂ O ₃ and other impurities, which will affect the purity of the extracted vanadium. Influence.

The invention patent with the publication number of "CN101491780" discloses a desulfurization slag powder treatment method and a desulfurization slag reuse method. The desulfurization slag powder treatment method is to perform magnetic separation after ball milling the desulfurization slag powder. The method for reusing the desulfurization slag includes crushing the desulfurization slag, and magnetically selecting large pieces of iron slag, and the rest is desulfurization slag powder, ball milling the desulfurization slag powder, performing magnetic separation, and blending the obtained high-iron material into sintering material. In view of the low-grade and unstable characteristics of desulfurization slag powder, a method of ball milling and then magnetic separation is adopted to effectively separate iron and slag in desulfurization slag powder, thereby improving the iron-containing grade of desulfurization slag powder and realizing the reduction of low-grade slag powder. The waste material is turned into a high-grade high-quality iron-containing raw material, that is, high-iron material. After the above-mentioned treatment, the high-iron material obtained is then mixed into sintering, which is beneficial to sintering production. It is especially suitable for the treatment of desulfurization slag of vanadium-titanium magnetite.

Han Xiaoyong of Meishan Iron and Steel Company Technology Center published the article "On the Utilization of Steel Slag", which disclosed the treatment method of using the metallic iron in steel slag after magnetic separation for converter smelting, mainly for the research on the recycling and reuse of steel slag.

In order to realize the comprehensive utilization of steel slag, reduce the discharge of solid waste, and reduce the pollution to the environment, Xichang Steel and Vanadium Steelworks of Panzhihua Iron and Steel Group specially adopts hot stuffy slag and crushing magnetic separation technology to process steel slag and realize the recovery of magnesite. Xichang Steelmaking Project has 400,000 tons of steel slag per year, and 29,200 tons of magnesite can be recovered after magnetic separation. The TFe content of magnesite can reach more than 80%, which has huge recycling value. Due to the high TFe content of magnesite (≥80%), low impurity content, etc., using magnesite as a vanadium extraction coolant has the advantages of high cooling strength, so it is considered to be used in the production of vanadium extraction coolant.

Contents of the invention

The first technical problem to be solved by the present invention is to provide a magnesium-containing vanadium-extracting coolant that can effectively reduce the carbon oxidation of molten iron, has good spherical shape and high strength.

The magnesium-containing vanadium-extracting coolant of the present invention consists of the following components in weight percent:

Magnesite 5～35%

Iron oxide scale 60~94%

Binder 1-5%;

Wherein, MgO>40wt% in the magnesite, P<0.05wt%, S<0.02wt%, particle size≤3mm;

The iron oxide scale is steelmaking iron oxide scale, wherein TFe>63wt%, P<0.02wt%, S<0.03wt%, particle size≤3mm;

The binder is at least one of bentonite, cement and diatomaceous earth.

Further, as a more preferred technical solution, the above-mentioned magnesium-containing vanadium-extracting coolant is preferably composed of the following components in weight percent:

Magnesite 5～35%

Iron oxide scale 62～92%

Binder 2 to 4%.

Further, as a more preferred technical solution, the above-mentioned magnesium-containing vanadium-extracting coolant is preferably composed of the following components in weight percent:

Magnesite 25%

Iron oxide scale 72%

Binder 3%.

The purpose of adding magnesite in the present invention is twofold: one is that the carbonate decomposition process needs to absorb heat, which can play a role in cooling; the other is that the _CO generated by the decomposition belongs to a weak oxidant and can participate in the oxidation of molten iron elements. In the process of extracting vanadium from the converter, in order not to bring in other impurity components, protect the lining of the converter, and comprehensively utilize the remaining ore residues, the present invention preferably adds magnesium-containing magnesite.

The second technical problem to be solved by the present invention is to provide a preparation method of a coolant containing magnesium for extracting vanadium.

The preparation method of above-mentioned extracting vanadium coolant, comprises the following steps:

a. Broken material: crush and sieve magnesite and steelmaking iron scale to obtain powders with a particle size of ≤3mm respectively for use;

B, batching: with the powder material and binding agent that step a obtains, according to the proportioning batching of magnesite, iron oxide scale and binding agent in the above-mentioned magnesium-containing vanadium extracting coolant, obtain compound;

c, mixing material: adding water to the mixing material obtained in step b, stirring, to obtain a mixed wet material; wherein, according to the weight ratio water: mixing material = 3:40～60;

d. Forming into balls: press the mixed wet material obtained in step c into balls, and dry to get final product.

The preparation method of the vanadium extracting coolant mentioned above, wherein, MgO>40wt% in the magnesite, P<0.05wt%, S<0.02wt%; the iron oxide scale is steelmaking iron oxide scale, wherein TFe>63wt% %, P<0.02wt%, S<0.03wt%; the binder is at least one of bentonite, cement and diatomaceous earth.

The preparation method of the vanadium extracting coolant described above, in order to improve the ball forming rate, preferably water in the c step according to the weight ratio:mixture=3:50, add water.

In the above-mentioned step d, the mixed material is directly sent to the briquetting machine for briquetting, and the unballed raw materials are returned to the briquetting machine hopper, and the pressed wet pellets are put into the iron grid hopper, in order to save energy , it can be air-dried for at least 2 days, and then the magnesium-containing vanadium-extracting coolant of the present invention can be obtained after drying.

The invention has the advantages of low cost, simple production process, high resource utilization rate, good cooling effect and the like. Not only can it provide high-quality coolant for vanadium extraction in converters, but it can also effectively reduce the carbon burning loss of molten iron in the vanadium extraction process, saving costs and creating benefits for enterprises. The vanadium extraction coolant prepared by the present invention—cold solidified pellets has uniform ball shape, good strength, will not break when dropped from a height of 2m, and has a ball forming rate as high as 85% at one time. Meet the requirements for vanadium extraction coolant. Not only can it ensure the cooling intensity required for vanadium extraction, it can effectively reduce the oxidation of molten iron carbon after use, and it can effectively utilize the remaining slag in steelmaking, improve the comprehensive utilization of resources, and help ensure the heat source for subsequent steelmaking.

Detailed ways

The magnesium-containing vanadium-extracting coolant of the present invention consists of the following components in weight percent:

Magnesite 5～35%

Iron oxide scale 60~94%

Binder 1-5%;

Wherein, MgO>40wt% in the magnesite, P<0.05wt%, S<0.02wt%, particle size≤3mm;

The iron oxide scale is steelmaking iron oxide scale, wherein TFe>63wt%, P<0.02wt%, S<0.03wt%, particle size≤3mm;

The binder is at least one of bentonite, cement and diatomaceous earth.

Further, as a more preferred technical solution, the above-mentioned magnesium-containing vanadium-extracting coolant is preferably composed of the following components in weight percent:

Magnesite 5～35%

Iron oxide scale 62～92%

Binder 2 to 4%.

Further, as a more preferred technical solution, the above-mentioned magnesium-containing vanadium-extracting coolant is preferably composed of the following components in weight percent:

Magnesite 25%

Iron oxide scale 72%

Binder 3%.

The purpose of adding magnesite in the present invention is twofold: one is that the carbonate decomposition process needs to absorb heat, which can play a role in cooling; the other is that the _CO generated by the decomposition belongs to a weak oxidant and can participate in the oxidation of molten iron elements. In the process of extracting vanadium from the converter, in order not to bring in other impurity components, protect the lining of the converter, and comprehensively utilize the remaining ore residues, the present invention preferably adds magnesium-containing magnesite.

The preparation method of above-mentioned extracting vanadium coolant, comprises the following steps:

a. Broken material: crush and sieve magnesite and steelmaking iron scale to obtain powders with a particle size of ≤3mm respectively for use;

B, batching: with the powder material and binding agent that step a obtains, according to the proportioning batching of magnesite, iron oxide scale and binding agent in the above-mentioned magnesium-containing vanadium extracting coolant, obtain compound;

c, mixing material: adding water to the mixing material obtained in step b, stirring, to obtain a mixed wet material; wherein, according to the weight ratio water: mixing material = 3:40～60;

d. Forming into balls: press the mixed wet material obtained in step c into balls, and dry to get final product.

The preparation method of the vanadium extracting coolant mentioned above, wherein, MgO>40wt% in the magnesite, P<0.05wt%, S<0.02wt%; the iron oxide scale is steelmaking iron oxide scale, wherein TFe>63wt% %, P<0.02wt%, S<0.03wt%; the binder is at least one of bentonite, cement and diatomaceous earth.

The preparation method of the vanadium extracting coolant described above, in order to improve the ball forming rate, preferably water in the c step according to the weight ratio:mixture=3:50, add water.

In the above-mentioned step d, the mixed material is directly sent to the briquetting machine for briquetting, and the unballed raw materials are returned to the briquetting machine hopper, and the pressed wet pellets are put into the iron grid hopper, in order to save energy , it can be air-dried for at least 2 days, and then the magnesium-containing vanadium-extracting coolant of the present invention can be obtained after drying.

The specific implementation of the present invention will be further described below in conjunction with the examples, and the present invention is not limited to the scope of the examples.

Example 1

Crush and sieve magnesite and steelmaking scale to obtain powders of ≤3mm, then mix 5t of magnesite, steelmaking scale and binder in a mass ratio of 5:92:3, and put them into the mixer During the mixing process, 300kg of water is evenly added, and after mixing evenly, the raw materials are sent to the briquetting machine for pressing, and the unballed raw materials are returned to the briquetting machine hopper, and the pressed wet pellets are put into the iron grid hopper, and naturally Air dry for 2 days. The obtained cold-set pellets have a one-time pelleting rate of 86.5%, uniform shape, good strength, and will not break when dropped from a height of 2m. The P content of the pellets is 0.027%, the S content is 0.05%, and the water content is 1.9%. Used as a coolant for vanadium extraction.

Example 2

Crush and sieve magnesite and steelmaking scale to obtain powders ≤ 3mm, then mix 10t of magnesite, steelmaking scale and binder in a mass ratio of 35:62:3, and put them into the mixer During the mixing process, 600kg of water is evenly added, and after mixing evenly, the raw materials are sent to the ball press machine for pressing, and the unballed raw materials are returned to the briquetting machine hopper, and the pressed wet pellets are put into the iron grid hopper, and naturally Air dry for 2 days. The obtained cold-set pellets have a one-time ball forming rate of 87%, uniform shape, good strength, and will not break when dropped from a height of 2m. Used as a coolant for vanadium extraction.

Example 3

Crush and sieve magnesite and steelmaking iron scale to obtain powder particles of ≤3mm, then mix 8t of magnesite, steelmaking iron scale and binder in a mass ratio of 25:72:3, and put them into the mixer During the mixing process, 480kg of water is evenly added, and after mixing evenly, the raw materials are sent to the briquetting machine for pressing, and the unballed raw materials are returned to the briquetting machine hopper, and the pressed wet pellets are put into the iron grid hopper, and naturally Air dry for 2 days. The resulting cold-set pellets have a one-time ball forming rate of 85.7%, uniform shape, good strength, and will not break when dropped from a height of 2m. Used as a coolant for vanadium extraction.

Claims (6)

1., containing magnesium vanadium-raising cooling agent, it is characterized in that: be made up of following weight percent composition:

Magnesite 5 ~ 35%

Iron scale 60 ~ 94%

Bonding agent 1 ~ 5%;

Wherein, MgO > 40wt%, P < 0.05wt% in described magnesite, S < 0.02wt%, particle diameter≤3mm;

Described iron scale is steel-making iron scale, wherein TFe > 63wt%, P < 0.02wt%, S < 0.03wt%, particle diameter≤3mm;

Described bonding agent is at least one in wilkinite, cement, diatomite.

2., according to claim 1 containing magnesium vanadium-raising cooling agent, it is characterized in that: be made up of following weight percent composition:

Magnesite 5 ~ 35%

Iron scale 62 ~ 92%

Bonding agent 2 ~ 4%.

3., according to claim 2 containing magnesium vanadium-raising cooling agent, it is characterized in that: be made up of following weight percent composition:

Magnesite 25%

Iron scale 72%

Bonding agent 3%.

4. contain the preparation method of magnesium vanadium-raising cooling agent described in any one of claims 1 to 3, it is characterized in that: comprise the following steps:

A, broken material: by magnesite, steel-making iron scale crushing and screening, obtain the powder of particle diameter≤3mm respectively, stand-by;

B, batching: the powder obtain a step and bonding agent, according to the proportion ingredient of magnesite, iron scale and bonding agent in any one of claims 1 to 3, obtain compound;

C, batch mixing: compound b step obtained adds water, stir, and obtains mixing wet feed; Wherein, according to weight ratio water: compound=3:40 ~ 60;

D, balling-up: the mixing wet feed compacting balling-up that step c is obtained, dry, to obtain final product.

5., according to claim 4 containing the preparation method of magnesium vanadium-raising cooling agent, it is characterized in that: CaO > 53wt%, P < 0.05wt%, S < 0.02wt% in magnesite; Iron scale is steel-making iron scale, wherein TFe > 63wt%, P < 0.02wt%, S < 0.03wt%; Bonding agent is at least one in wilkinite, cement, diatomite.

6. according to claim 4 or 5, contain the preparation method of magnesium vanadium-raising cooling agent, it is characterized in that: according to weight ratio water in described step c: compound=3:50, adds water.