Sintering method of limonite type laterite-nickel ore

Abstract

The invention discloses a limonite type laterite-nickel ore sintering method which comprises the following steps: step 1, taking limonite type laterite-nickel ore, drying the limonite type laterite-nickel ore, dividing the dried limonite type laterite-nickel ore into two parts, namely a material part A and a material part B, and modifying the limonite type laterite-nickel ore in the material part A to obtain modified laterite; 2, the modified laterite, the limonite-type laterite-nickel ore of the material B, fuel, flux and return mine are subjected to burdening and uniform mixing to obtain a mixture, and the mixture is granulated and sintered to obtain limonite-type laterite-nickel ore sintered ore; wherein the modified laterite is oxidized laterite and / or magnetized laterite. The modified laterite ore is prepared from part of the limonite type laterite-nickel ore, the adding proportion of different modified laterite ore can be adjusted according to requirements, other minerals are not introduced, and the sintered ore of the limonite type laterite-nickel ore can serve as high-quality furnace charge of a blast furnace, is high in product yield and drum strength and meets the requirements of the furnace charge of the blast furnace.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a sintering method of limonite-type laterite nickel ore. Background Art

[0002] Researchers have developed a series of processes and technologies for efficiently extracting nickel and cobalt from laterite nickel ore. The energy consumption and production costs of wet processing of laterite nickel ore are significantly lower than those of pyrometallurgical processes. However, compared with pyrometallurgical processes, wet processing is limited by factors such as smaller production scale and longer production processes, resulting in a smaller proportion of nickel produced from laterite nickel ore.

[0003] Currently, laterite nickel ore is too fine-grained and must be artificially agglomerated to a certain particle size before blast furnace smelting. The agglomeration process not only changes the particle size composition and mechanical strength of the ore, but also produces sintered ore with many smelting properties superior to natural ore. It also has sufficient basicity and allows for pre-slagging, allowing for minimal or no flux addition in the subsequent blast furnace smelting process. This removes impurities, improves ore quality, and alters the ore phase structure and metallurgical properties. Currently, sintering is the most widely used method for blast furnace smelting of laterite nickel ore. Limonite-type laterite nickel ore, which is an oxidized ore, is generally characterized by a high water content. In addition to water, it also contains water of crystallization and hydroxyl water, with a total content often exceeding 30%. Moreover, as a hydrophilic substance, limonite-type laterite nickel ore often needs to be added with more water during the mixing process to ensure effective granulation moisture, which is inconsistent with actual production requirements. In addition, excessive moisture leads to the need to dry the laterite nickel ore before raw material mixing in actual production. The dried laterite nickel ore is easy to agglomerate and has an extremely fine particle size, which can account for more than 60% under a 400-mesh sieve. Considering the existing conditions, the moisture treatment in the laterite nickel ore has become one of the keys to improving the sintering quality.

[0004] Unlike carbon steel sintering, laterite nickel ore, especially limonite-type laterite nickel ore, is not well suited for acidic pellets. In the stainless steel industry, the typical blast furnace ore mix consists of over 80% sintered ore, along with approximately 10% lump ore and fuel. Therefore, the high alkalinity, high temperature, and increased liquid calcium ferrite content typical of carbon steel sintering are uncommon in stainless steel sintering using laterite nickel ore. The typical alkalinity of laterite nickel ore is 1.5. Due to the high fuel consumption associated with high moisture content and high fuel consumption, the relatively low combustion temperatures are insufficient to support the conversion of a significant amount of liquid calcium ferrite into fayalite, making it difficult to achieve the desired alkalinity in actual production. In summary, laterite nickel ore sintering, compared to carbon steel sintering, presents many technical challenges that must be addressed, and the technical specifications of carbon steel sintering cannot be simply applied to laterite nickel ore sintering. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a sintering method of limonite-type laterite-nickel ore which has a simple preparation method and does not introduce other minerals, and the prepared limonite-type laterite-nickel ore can be used as a high-quality blast furnace charge.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows: a sintering method of limonite-type laterite nickel ore, comprising the following steps:

[0007] Step 1: taking a limonite-type laterite nickel ore, drying it and dividing it into two parts, namely, a material A part and a material B part, and modifying the limonite-type laterite nickel ore of the material A part to obtain a modified laterite ore;

[0008] Step 2: The modified laterite ore, the limonite-type laterite nickel ore of material B, the fuel, the flux and the return ore are batched and mixed to obtain a mixture, and the mixture is granulated and then sintered to obtain the limonite-type laterite nickel ore sinter;

[0009] Wherein, the modified laterite is oxidized laterite and / or magnetized laterite.

[0010] The sintering method described in the above technical solution meets at least one of the following conditions A to K:

[0011] A: The drying temperature in step 1 is 50-300°C (can be any value of 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C, 290°C and 300°C, or a range corresponding to any two values); the moisture content of the limonite-type laterite nickel ore after drying is less than 1wt%;

[0012] B: The amount of fuel added in step 2 is 1-10% of the total weight of the mixture (which can be any value among 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% and 10%, or a range corresponding to any two values);

[0013] C: The amount of flux added in step 2 is 0-15% of the total weight of the mixture (which can be any value among 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% and 15%, or a range corresponding to any two values);

[0014] D: the addition amount of the return ore in the step 2 accounts for 0-33% of the total weight of the mixture (which can be 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32% and 33% of any value or the range corresponding to any two values), wherein the return ore is a limonite-type laterite nickel ore sinter with a particle size of <5mm after sintering is completed and used as the return ore;

[0015] E: The flux is a clinker flux;

[0016] F: The fuel comprises at least one of anthracite and coke;

[0017] G: The proportion of particles with a particle size greater than 3 mm in the fuel is less than 10 wt % (which can be any value selected from 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% and 10%, or a range corresponding to any two values), and the proportion of particles with a particle size less than 0.5 mm is less than 15 wt % (which can be any value selected from 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% and 15%, or a range corresponding to any two values);

[0018] H: The mixing equipment in step 2 is a drum mixer or a powerful mixer (of course, not limited to these), and the mixing time is 0-20 min (which can be any value among 0 min, 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min and 20 min, or a range corresponding to any two values);

[0019] I: The water content of the mixture in step 2 is 5-25wt% (which can be any value among 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt% and 25wt%, or the range corresponding to any two values);

[0020] J: The sintering process in step 2 is carried out on a belt sintering machine, the ignition temperature is 1000-1200°C (can be any value among 1000°C, 1010°C, 1020°C, 1030°C, 1040°C, 1050°C, 1060°C, 1070°C, 1080°C, 1090°C, 1100°C, 1110°C, 1120°C, 1130°C, 1140°C, 1150°C, 1160°C, 1170°C, 1180°C, 1190°C, 1200°C or the range corresponding to any two values), and the ignition time is 1-5 min (can be any value among 1 min, 2 min, 3 min, 4 min and 5 min or the range corresponding to any two values). 31 min, 32 min, 33 min, 34 min, 35 min, 36 min, 37 min, 38 min, 39 min and 40 min, any one of the values ​​or the range corresponding to any two values);

[0021] K: The proportion of material A in the step 1 is at least 5 wt% of the total amount of the limonite-type laterite nickel ore after drying (it can be any value among 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt%, 90 wt% and 100 wt% or the range corresponding to any two values).

[0022] The clinker flux in the above technical solution is quicklime and / or active lime.

[0023] The preparation method of the oxidized laterite ore in the above technical solution is to oxidize and roast the limonite-type laterite nickel ore to prepare the oxidized laterite ore.

[0024] The temperature of oxidation roasting described in the above-mentioned technical scheme is 600-1000 ℃ (can be any value among 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃ and 1000 ℃ or the scope corresponding between any two values), and the oxidation roasting time is 10-120min (can be any value among 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, 60min, 65min, 70min, 75min, 80min, 85min, 90min, 95min, 100min, 105min, 110min, 115min and 120min or the scope corresponding between any two values).

[0025] The preparation method of the magnetized laterite ore in the above technical solution is to mix limonite-type laterite nickel ore and a reducing agent uniformly and then magnetize and roast the mixture.

[0026] The temperature of the magnetization roasting in the above technical solution is 650-900° C. (which can be any value among 650° C., 700° C., 750° C., 800° C., 850° C. and 900° C., or a range corresponding to any two values), and the time of the magnetization roasting is 10-120 min (which can be any value among 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min, 90 min, 95 min, 100 min, 105 min, 110 min, 115 min and 120 min, or a range corresponding to any two values).

[0027] The reducing agent in the above technical solution includes a solid reducing agent and / or a gaseous reducing agent.

[0028] In the above technical solution, the solid reducing agent is anthracite, the gas reducing agent is CO and / or H2, and the amount of the solid reducing agent added is 5-30% of the mass of the limonite-type laterite nickel ore participating in the magnetization modification (which can be any value among 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29 and 30% or the range corresponding to any two values), and the concentration of the gas reducing agent is not less than 10vol% (which can be 10vol%, 20vol%, 30vol%, 40vol%, 50vol%, 60vol%, 70vol%, 80vol%, 90vol% and 100vol%). l% of any value or the corresponding range between any two values).

[0029] A second object of the present invention is to provide a limonite-type laterite nickel ore prepared by the sintering method as described above.

[0030] The beneficial effects of the present invention are as follows: the present invention uses part of the limonite-type laterite-nickel ore to prepare the modified laterite ore, the addition ratio of different modified laterites can be adjusted according to demand, and no other minerals are introduced; the limonite-type laterite-nickel ore provided by the present invention is a sintered ore that can be used as a high-quality blast furnace charge, has a high product yield and high drum strength, and meets the requirements of blast furnace charge; and the present invention modifies the limonite-type laterite-nickel ore by pre-heat treatment, which can improve the heat utilization efficiency and further significantly improve the yield, drum strength and metallurgical properties of the limonite-type laterite-nickel ore sinter. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the process of the sintering method of limonite-type laterite nickel ore according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The principles and features of the present invention are described below with reference to the following embodiments. The examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. The following paragraphs describe the present invention in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present invention will be more clearly described in accordance with the following description and claims.

[0033] like Figure 1As shown, this embodiment provides a sintering method for limonite-type laterite-nickel ore, comprising the following steps: Step 1: taking limonite-type laterite-nickel ore, drying it and dividing it into two parts, namely, material A and material B, and modifying the limonite-type laterite-nickel ore of material A to obtain modified laterite ore; Step 2: batching and mixing the modified laterite ore, the limonite-type laterite-nickel ore of material B, fuel, flux and return ore to obtain a mixture, granulating the mixture and sintering it to obtain limonite-type laterite-nickel ore sinter; wherein the modified laterite ore is oxidized laterite ore and / or magnetized laterite ore.

[0034] Example 1

[0035] A limonite-type laterite nickel ore having a TFe content of 46.0 wt% and a Ni content of 0.8 wt% is dried at 150° C. for 120 minutes, and then mixed with a reducing agent (anthracite powder) having a particle size of less than 1 mm to obtain a batch, wherein the weight of the reducing agent accounts for 15% of the total weight of the batch. The batch is then magnetized and roasted at 750° C. for 20 minutes to obtain a magnetized laterite ore.

[0036] The prepared magnetized laterite, fuel (anthracite), flux (quicklime) and return ore are mixed to obtain a mixture, wherein the amount of fuel added is 5.2% of the total weight of the mixture, the amount of return ore added is 30% of the total weight of the mixture, and the amount of flux added is such that CaO / SiO2 in the mixture is 1.6 (mass ratio). The mixture is mixed twice during mixing, each mixing time is 5 minutes, and the moisture content of the mixture is controlled to be 20wt% during mixing. Then, sintering is carried out. During sintering, the height of the material layer is 700mm, the ignition temperature is 1100°C, the ignition time is 2 minutes, the sintered ore yield is 73% (the sintered ore yield is the yield of limonite-type laterite nickel ore sintered ore with a particle size of ≥5mm after sintering), and the drum strength is 50%.

[0037] Example 2

[0038] Drying a limonite-type nickel laterite ore having a TFe content of 44.3 wt% and a Ni content of 0.7 wt% at 150° C. for 120 min, and then oxidatively roasting the ore at 700° C. for 120 min to obtain an oxidized laterite ore;

[0039] The prepared oxidized laterite ore, fuel (anthracite), flux (quicklime) and return ore are mixed to obtain a mixture, wherein the amount of fuel added to the mixture is 5.2% of the total weight of the mixture, the amount of return ore added is 30% of the total weight of the mixture, and the amount of flux added is such that CaO / SiO2 in the mixture is 1.6 (mass ratio). The mixture is mixed twice during mixing, each mixing time is 5 minutes, and the moisture content of the mixture is controlled to be 20wt% during mixing. Then, sintering is carried out. During sintering, the height of the material layer is 700mm, the ignition temperature is 1100℃, the ignition time is 2 minutes, the sintered ore yield is 62%, and the drum strength is 48%.

[0040] Example 3

[0041] A limonite-type laterite nickel ore having a TFe content of 44.3 wt% and a Ni content of 0.7 wt% was dried at 150° C. for 120 min, and then divided into three portions, namely, portion A and portion B (wherein portion A was divided into two, one portion was used to prepare magnetized laterite ore according to the method in Example 1; the other portion was used to prepare oxidized laterite ore according to the method in Example 2);

[0042] The prepared magnetized laterite, oxidized laterite and limonite-type laterite-nickel ore of material B are mixed to prepare a mixed ore, wherein the addition amount of the magnetized laterite and oxidized laterite each accounts for 30% of the total weight of the mixed ore, and the remainder is the limonite-type laterite-nickel ore in material B. The mixed ore, fuel (anthracite), flux (quicklime) and return ore are mixed to obtain a mixture, wherein the addition amount of the fuel is 5.2% of the total weight of the mixture, the addition amount of the return ore is 30% of the total weight of the mixture, and the addition amount of the flux is such that CaO / SiO2=1.6 (mass ratio) in the mixture. The mixture is mixed twice during mixing, each mixing time is 5 minutes, the moisture content of the mixture is controlled to be 20wt% during mixing, and then sintering is carried out. During sintering, the height of the material layer is 700 mm, the ignition temperature is 1100° C., the ignition time is 2 minutes, the sintered ore yield is 80%, and the drum strength is 58%.

[0043] Example 4

[0044] The same as Example 3, except that the mass ratio of magnetized laterite ore, oxidized laterite ore and limonite-type laterite nickel ore in the mixed ore is 3:0:7, the sintered ore yield is 65%, and the drum strength is 50%.

[0045] Example 5

[0046] The same as Example 4, except that the mass ratio of magnetized laterite ore, oxidized laterite ore and limonite-type laterite nickel ore in the mixed ore is 0:3:7, the sintered ore yield is 55%, and the drum strength is 45%.

[0047] Example 6

[0048] The same as Example 4, except that the mass ratio of magnetized laterite ore, oxidized laterite ore and limonite-type laterite nickel ore in the mixed ore is 1.5:1.5:7, the sintered ore yield is 53%, and the drum strength is 42%.

[0049] Comparative Example 7

[0050] The same as Example 6, except that the mass ratio of magnetized laterite ore, oxidized laterite ore and limonite-type laterite nickel ore in the mixed ore is 1:1:8, the sintered ore yield is 51%, and the drum strength is 40%.

[0051] Example 8

[0052] The same as Example 6, except that the mass ratio of magnetized laterite ore, oxidized laterite ore and limonite-type laterite nickel ore in the mixed ore is 2:0:8, the sintered ore yield is 48%, and the drum strength is 44%.

[0053] Example 9

[0054] The same as Example 6, except that the mass ratio of magnetized laterite ore, oxidized laterite ore and limonite-type laterite nickel ore in the mixed ore is 0:2:8, the sintered ore yield is 46.6%, and the drum strength is 40.2%.

[0055] Comparative Example

[0056] A limonite-type laterite nickel ore with a TFe of 46.0wt% and a Ni of 0.8wt% is prepared for use, and the ore is mixed with a fuel (anthracite), a flux (quicklime) and a return ore to obtain a mixture, wherein the amount of fuel added is 5.2% of the total weight of the mixture, and the amount of return ore added is 30% of the total weight of the mixture. The amount of flux added is such that CaO / SiO2 in the mixture is 1.6 (mass ratio). The mixture is mixed twice during mixing, each mixing time is 5 minutes, and the moisture content of the mixture is controlled to be 20wt% during mixing. Then, sintering is carried out, and the height of the material layer during sintering is 700mm, the ignition temperature is 1100°C, the ignition time is 2 minutes, the sintered ore yield is 46%, and the drum strength is 35%.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A sintering method for limonite-type laterite nickel ore, characterized in that: The steps include: Step 1: taking a limonite-type laterite nickel ore, drying it and dividing it into two parts, namely, a material A part and a material B part, and modifying the limonite-type laterite nickel ore of the material A part to obtain a modified laterite ore; Step 2: The modified laterite ore, the limonite-type laterite nickel ore of material B, the fuel, the flux and the return ore are batched and mixed to obtain a mixture, and the mixture is granulated and then sintered to obtain the limonite-type laterite nickel ore sinter; Wherein, the modified laterite is oxidized laterite and / or magnetized laterite.

2. The sintering method of limonite-type laterite nickel ore according to claim 1, characterized in that: The sintering method meets at least one of the following conditions A to K: A: The drying temperature in step 1 is 50-300° C.; the moisture content of the limonite-type laterite nickel ore after drying is less than 1 wt %; B: The amount of fuel added in step 2 is 1-10% of the total weight of the mixture; C: The amount of flux added in step 2 is 0-15% of the total weight of the mixture; D: The amount of the returned ore added in step 2 is 0-30% of the total weight of the mixture, wherein the returned ore is a limonite-type laterite nickel ore sinter with a particle size of less than 5 mm after sintering. E: The flux is a clinker flux; F: The fuel comprises at least one of anthracite and coke; G: The proportion of particles with a particle size greater than 3 mm in the fuel is less than 10 wt%, and the proportion of particles with a particle size less than 0.5 mm is less than 15 wt%; H: The mixing equipment in step 2 is a drum mixer or a powerful mixer, and the mixing time is 0-20 minutes; I: The water content of the mixture in step 2 is 5-25wt%; J: The sintering process in step 2 is carried out on a belt sintering machine with an ignition temperature of 1000-1200°C, an ignition time of 1-5 minutes, and a sintering time of 10-40 minutes; K: The proportion of material A in step 1 is at least 5 wt% of the total amount of the dried limonite-type laterite nickel ore.

3. The sintering method of limonite-type laterite nickel ore according to claim 2, characterized in that: The clinker flux is quicklime and / or active lime.

4. The sintering method of limonite-type laterite nickel ore according to claim 1, characterized in that: The preparation method of the oxidized laterite ore is to oxidize and roast the limonite-type laterite nickel ore to prepare the oxidized laterite ore.

5. The sintering method of limonite-type laterite nickel ore according to claim 4, characterized in that: The temperature of the oxidation roasting is 600-1000° C., and the oxidation roasting time is 10-120 minutes.

6. The sintering method of limonite-type laterite nickel ore according to claim 2, characterized in that: The preparation method of the magnetized laterite ore is to mix limonite-type laterite nickel ore and a reducing agent uniformly and then magnetize and roast the mixture.

7. The sintering method of limonite-type laterite nickel ore according to claim 6, characterized in that: The temperature of the magnetization roasting is 650-900° C., and the time of the magnetization roasting is 10-120 minutes.

8. The sintering method of limonite-type laterite nickel ore according to claim 6, characterized in that: The reducing agent includes a solid reducing agent and / or a gaseous reducing agent.

9. The sintering method of limonite-type laterite nickel ore according to claim 8, characterized in that: The solid reducing agent is anthracite, the gas reducing agent is CO and / or H2, and the amount of the solid reducing agent added is 5-30% of the mass of the limonite-type laterite nickel ore involved in magnetization modification, and the concentration of the gas reducing agent is not less than 10 vol%.

10. A limonite-type laterite nickel ore, characterized in that: The sintering method is adopted as claimed in any one of claims 1 to 9.

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