Iron-based adhesive material and preparation method thereof

Abstract

The invention mainly relates to the technical field of pelletizing and pellet preparation, in particular to an iron-based adhesive and a preparation method thereof.The iron-based adhesive is prepared from, by weight, 10-20 parts of laterite-nickel ore, 1-4 parts of composite bentonite and 1-2 parts of anti-explosion agent; wherein the composite bentonite is prepared from the following components in percentage by mass: 70 to 80 percent of sodium bentonite, 10 to 15 percent of alkaline mineral micro powder, 2 to 5 percent of binder and 1 to 3 percent of sintering aid. According to the iron-based adhesive prepared through the technical scheme, the bonding performance is guaranteed, meanwhile, acid gangue is reduced, the iron grade is improved, cost is reduced through low-price raw materials, and finally the smelting performance and economical efficiency of pellets are optimized.

Description

TECHNICAL FIELD

[0001] The application mainly relates to the technical field of pelletizing and pellet production, and particularly relates to an iron-based binder and a preparation method thereof. BACKGROUND

[0002] In the steel industry, the pellet is one of the main forms of iron ore powder agglomeration, which is made into blocky raw materials with good metallurgical properties through processes such as pelletizing, drying and roasting, and is used for blast furnace ironmaking. In the pelletizing process, the selection of the binder directly affects the pelletizing property, strength, grade and production energy consumption of the pellet.

[0003] In the production process of the pellet in the steel metallurgy, the performance of the binder directly affects the quality of the pellet, the smelting efficiency and the production cost. Although the bentonite-based binder widely used in the traditional process can meet the basic bonding requirements, it has an insurmountable technical bottleneck: on the one hand, the bentonite itself contains a high content of SiO2, Al2O3 and other acidic gangue components, and a large amount of addition will significantly dilute the proportion of iron elements in the pellet, reduce the iron grade, and further increase the flux consumption and energy consumption in the subsequent smelting link, which is contrary to the requirement of the steel industry to low-carbon and high-efficiency transformation; on the other hand, in order to ensure the green ball strength and the roasting stability, the amount of bentonite is usually difficult to reduce, which further aggravates the problem of accumulation of acidic gangue.

[0004] Therefore, an iron-based binder material and a preparation method thereof are needed to solve the above problems. SUMMARY

[0005] To achieve the above-mentioned purpose, the following technical solutions are implemented. An iron-based binder material, consisting of the following components in parts by weight: 10-20 parts of laterite nickel ore, 1-4 parts of composite bentonite, and 1-2 parts of anti-explosion agent. The composite bentonite includes 70-80% of sodium-based bentonite, 10-15% of alkaline mineral micro powder, 2-5% of binder, and 1-3% of sintering aid in terms of mass fraction.

[0006] Further, the mass of water in the laterite nickel ore accounts for less than 10% of the total mass.

[0007] Further, the alkaline mineral micro powder is any one of dolomite powder and light-burned magnesia powder.

[0008] Further, the binder is any one of sodium carboxymethyl cellulose and starch graft copolymer.

[0009] Further, the sintering aid is any one of borax and spodumene powder.

[0010] Further, the explosion-proof agent is prepared by sodium bicarbonate and calcium dihydrogen phosphate, and the mass ratio of sodium bicarbonate to calcium dihydrogen phosphate is 1:3.

[0011] Further, a preparation method of the iron-based binder material comprises the following steps: In step 100, the composite bentonite is pre-activated, and sodium-based bentonite, alkaline mineral powder, binder and sintering aid are mixed at a preset ratio at 50-60 DEG C for 30 minutes to obtain the composite bentonite. In step 200, the laterite nickel ore is dried, and the laterite nickel ore is placed in a dryer and dried at 80-120 DEG C, so that the mass of water in the laterite nickel ore accounts for less than 10% of the total mass. In step 300, the composite bentonite, the explosion-proof agent and the laterite nickel ore are mixed and finely ground in a vertical mill, and more than 95% of the particles pass through a 200-mesh standard sieve.

[0012] Compared with the prior art, the beneficial effects of the present application are that, in the present scheme, the alkaline mineral powder, the binder and the sintering aid are introduced into the composite bentonite, on the one hand, the alkaline mineral powder can actively react with the acid gangue, which can effectively reduce the content of the acid gangue in the iron-based binder material, and greatly reduce the acid load of the pellet, on the other hand, the binder enhances the green ball strength and the balling rate, and at the same time, the low melting point characteristic of the sintering aid can become liquid phase in time to fill the gap between the particles.

[0013] In addition, the laterite nickel ore as a low-price iron-containing raw material can greatly reduce the raw material cost while ensuring the performance, and finally form a pellet that takes into account low gangue, high grade, high stability and economy, to meet the industrial demand. BRIEF DESCRIPTION OF DRAWINGS

[0014] In addition Figure 1 It is the flow process chart of the preparation method in the present application. DETAILED DESCRIPTION

[0015] The present application will be further described in conjunction with the drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application. In addition, it should be understood that after reading the content taught by the present application, those skilled in the art can make various modifications or modifications to the present application, and these equivalent forms also fall within the scope defined by the present application.

[0016] An iron-based binder material, by weight parts, consists of: 10-20 parts of laterite nickel ore, 1-4 parts of composite bentonite, 1-2 parts of explosion-proof agent; wherein the composite bentonite, by mass fraction, comprises 70-80% of sodium-based bentonite, 10-15% of alkaline mineral powder, 2-5% of binder, and 1-3% of sintering aid.

[0017] The alkaline mineral powder is any one of dolomite powder and light-burned magnesium oxide powder, and the dolomite powder and the light-burned magnesium oxide powder can respectively react with the acid gangue to reduce the content of the acid gangue in the iron-based binder, the dolomite powder is an alkaline carbonate, and a product of decomposition of the dolomite powder at high temperature can react with the silicon dioxide in the acid gangue to generate a calcium-magnesium silicate; the light-burned magnesium oxide powder is an alkaline oxide, and can react with the Al2O3 in the acid gangue to reduce the acid effect of the free Al2O3.

[0018] The binder is any one of carboxymethyl cellulose and starch graft copolymer, and the binder has a large number of hydroxyl groups and carboxyl groups in the molecular chain, can form a coordination bond with metal ions in the laterite nickel ore, and can also combine with the montmorillonite particles in the composite bentonite through hydrogen bonds to enhance the connection between the laterite nickel ore and the composite bentonite.

[0019] The sintering aid is any one of borax and spodumene powder, and the sintering aid can be molten to form a liquid phase to fill the gaps between the particles and promote the sintering of the pellets at the time of sintering of the pellets.

[0020] The explosion-proof agent is prepared by compounding sodium bicarbonate and calcium dihydrogen phosphate, and the mass ratio of the sodium bicarbonate to the calcium dihydrogen phosphate is 1:3.

[0021] A preparation method of the iron-based binder material, comprising the following steps: Step 100, the composite bentonite is pre-activated, and the sodium-based bentonite, the alkaline mineral powder, the binder and the sintering aid are mixed at a preset ratio at 50-60 DEG C for 30 min to obtain the composite bentonite; Step 200, the laterite nickel ore is dried, and the laterite nickel ore is placed in a dryer and dried at 80-120 DEG C, so that the mass of water in the laterite nickel ore accounts for less than 10% of the total mass; Step 300, mixing and fine grinding, the composite bentonite, the explosion-proof agent and the laterite nickel ore are added to a vertical mill for mixing and fine grinding, and more than 95% of the particles pass through a 200-mesh standard sieve, the finer the laterite nickel ore particles, the larger the contact area with the composite bentonite colloid, and the stronger the physical adsorption and chemical action between the interfaces, which is beneficial to enhancing the compressive strength of the green pellets.

[0022] Example 1 An iron-based binder material, consisting of the following components by weight parts: 10 parts of laterite nickel ore, 1 part of composite bentonite, 1 part of explosion-proof agent; wherein the composite bentonite, by mass fraction, includes 80% of sodium-based bentonite, 15% of dolomite powder, 3% of carboxymethyl cellulose, and 2% of borax.

[0023] A preparation method for preparing the above-mentioned iron-based binder material, comprising the following steps: Step 100, composite bentonite pre-activation, mix sodium-based bentonite, dolomite powder, carboxymethyl cellulose, and borax at a predetermined ratio at 50°C for 30 min to obtain composite bentonite; Step 200, drying of laterite nickel ore, place the laterite nickel ore into a dryer and dry it at 80°C, so that the mass of water in the laterite nickel ore accounts for 8% of the total mass; Step 300, mixing and fine grinding, add composite bentonite, explosion-proof agent, and laterite nickel ore into a vertical mill according to a predetermined proportion for mixing and fine grinding to obtain an iron-based binder material.

[0024] Example 2 An iron-based binder material, consisting of the following components by weight parts: 20 parts of laterite nickel ore, 4 parts of composite bentonite, and 2 parts of explosion-proof agent; wherein the composite bentonite, by mass fraction, includes 77% of sodium-based bentonite, 15% of light-burned magnesium oxide powder, 5% of starch graft copolymer, and 3% of spodumene powder.

[0025] A preparation method for preparing the above-mentioned iron-based binder material, combined with the above Figure 1 comprising the following steps: Step 100, composite bentonite pre-activation, mix sodium-based bentonite, light-burned magnesium oxide powder, starch graft copolymer, and spodumene powder at a predetermined ratio at 60°C for 30 min to obtain composite bentonite; Step 200, drying of laterite nickel ore, place the laterite nickel ore into a dryer and dry it at 120°C, so that the mass of water in the laterite nickel ore accounts for 6% of the total mass; Step 300, mixing and fine grinding, add composite bentonite, explosion-proof agent, and laterite nickel ore into a vertical mill according to a predetermined proportion for mixing and fine grinding to obtain an iron-based binder material.

[0026] Example 3 An iron-based binder material, consisting of the following components by weight parts: 15 parts of laterite nickel ore, 2 parts of composite bentonite, and 1.5 parts of explosion-proof agent; wherein the composite bentonite, by mass fraction, includes 80% of sodium-based bentonite, 14% of dolomite powder, 5% of carboxymethyl cellulose, and 1% of borax.

[0027] A preparation method of the above-mentioned iron-based binder material, comprising the following steps: Step 100, pre-activation of composite bentonite, sodium-based bentonite, dolomite powder, carboxymethyl cellulose, borax are mixed at 55℃ for 30min according to the preset ratio to obtain composite bentonite; Step 200, drying of laterite nickel ore, the laterite nickel ore is placed into a dryer and dried at 100℃, so that the mass of water in the laterite nickel ore accounts for 7% of the total mass; Step 300, mixing and fine grinding, the composite bentonite, the explosion-proof agent and the laterite nickel ore are added into a vertical mill for mixing and fine grinding to obtain the iron-based binder material.

[0028] Example 4 An iron-based binder material, consisting of the following components by weight parts: 18 parts of laterite nickel ore, 3 parts of composite bentonite, 1.2 parts of explosion-proof agent; wherein the composite bentonite, by mass fraction, includes 79% of sodium-based bentonite, 15% of light burned magnesia powder, 4% of starch graft copolymer, and 2% of spodumene powder.

[0029] A preparation method of the above-mentioned iron-based binder material, comprising the following steps: Step 100, pre-activation of composite bentonite, sodium-based bentonite, light burned magnesia powder, starch graft copolymer, spodumene powder are mixed at 58℃ for 30min according to the preset ratio to obtain composite bentonite; Step 200, drying of laterite nickel ore, the laterite nickel ore is placed into a dryer and dried at 90℃, so that the mass of water in the laterite nickel ore accounts for 9% of the total mass; Step 300, mixing and fine grinding, the composite bentonite, the explosion-proof agent and the laterite nickel ore are added into a vertical mill for mixing and fine grinding to obtain the iron-based binder material.

[0030] The iron-based binder materials prepared in Examples 1-4 are subjected to performance testing, and the reduction index, reduction expansion rate, green ball drop strength, green ball compressive strength, 8-19mm balling rate, and calcined ball compressive strength of the iron-based binder material are obtained, and the performance test data are shown in the following table:

[0031] In summary, through the performance test data of the above-mentioned four examples, it is shown that the addition of laterite nickel ore and the addition of alkaline mineral powder, binder and low-melting point sintering aid in the composite bentonite can improve the drop strength and compressive strength of the green ball, and reduce the content of acid gangue in the iron-based binder material, and at the same time improve the stability of calcination.

[0032] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An iron-based binder material, characterized in that: 10-20 parts of laterite nickel ore, 1-4 parts of composite bentonite, and 1-2 parts of explosion-proof agent by weight; wherein the composite bentonite comprises 70-80% sodium-based bentonite, 10-15% alkaline mineral powder, 2-5% binder, and 1-3% sintering aid by mass fraction.

2. The iron-based binder material according to claim 1, characterized in that: The moisture content in the laterite nickel ore is less than 10% of the total mass.

3. The iron-based binder material according to claim 1, characterized in that: The alkaline mineral powder is any one of dolomite powder or light-burned magnesium oxide powder.

4. The iron-based binder material according to claim 1, characterized in that: The binder is any one of sodium carboxymethyl cellulose or starch graft copolymer.

5. The iron-based binder material according to claim 1, characterized in that: The sintering aid is any one of borax or spodumene powder.

6. The iron-based binder material according to claim 1, characterized in that: The explosion-proof agent is prepared by compounding sodium bicarbonate and calcium dihydrogen phosphate, and the mass ratio of sodium bicarbonate to calcium dihydrogen phosphate is 1:

3.

7. A preparation method of the iron-based binder material according to any one of claims 1-6, characterized in that: The method comprises the following steps: Step 100, composite bentonite pre-activation, mix sodium-based bentonite, alkaline mineral powder, binder, and sintering aid at a predetermined ratio at 50-60°C for 30 min to obtain composite bentonite; Step 200, laterite nickel ore drying, place the laterite nickel ore in a drying machine and dry it at 80-120°C so that the moisture content in the laterite nickel ore is less than 10% of the total mass; Step 300, mixing and fine grinding, add composite bentonite, explosion-proof agent, and laterite nickel ore to a vertical mill in a predetermined proportion for mixing and fine grinding, and more than 95% of the particles pass through a 200-mesh standard sieve.

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