A high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method
By dividing the high-ice nickel smelting process into multiple stages and adding reducing agents and fluxes to the depleted electric furnace, depleted iron containing nickel chromium is solved, and the problems of low iron recovery and low production efficiency in the existing high-ice nickel hot slag treatment technology are achieved, achieving efficient iron recovery and optimization of production processes.
Patent Information
- Application Number
- CN202411983900.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-04-04
AI Technical Summary
The existing high-ice nickel hot slag treatment technology has problems such as low iron recovery rate, low production efficiency, many equipment and long process flow, and difficulty in effectively using sulfur elements.
By dividing the high ice nickel smelting process into multiple stages, using a depleted electric furnace to lift iron, and adding reducing agent and flux to the depleted electric furnace to produce depleted iron containing nickel chromium, and at the same time, the depleted tailings and cement clinker are mixed to make concrete.
The iron recovery rate during iron extraction is improved, the proportion of hot slag recovery in high ice nickel state is reduced, the process flow is shortened, the production efficiency is improved, and sulfur is effectively utilized.
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Figure CN119753351A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of high-grade nickel matte hot slag treatment, and in particular to a high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method. Background Art
[0002] The production and preparation of high nickel matte is mainly divided into two process routes: wet method and pyrometallurgy. The slags produced are acid leaching slag and hot slag respectively. The main component of hot slag is ferrous silicate, and iron accounts for about 40% to 60%. The remaining components are compounds of sulfur, silicon, magnesium, calcium, nickel, and chromium. The production process and treatment method of hot slag mainly use low nickel matte as raw material, and blow it through an oxygen-enriched continuous side-blowing furnace to obtain medium nickel matte products and continuous blowing slag. The medium nickel matte enters the converter and is smelted to obtain high nickel matte and high nickel matte hot slag. The high nickel matte hot slag returns to the oxygen-enriched continuous side-blowing furnace for re-smelting. The continuous blowing slag is settled in the settling electric furnace to obtain settled medium nickel matte and electric furnace slag. The settled medium nickel matte and the medium nickel matte produced by the oxygen-enriched continuous side-blowing furnace are put into the converter to smelt high nickel matte. The electric furnace slag enters the iron-raising furnace to produce ordinary carbon hot metal by adding a reducing agent. The main disadvantage of this method is that the slag gold content is relatively high during the smelting of medium nickel matte to high nickel matte, and the ratio is usually above 3. This means that less than 1 / 3 of the medium nickel matte produced by the oxygen-enriched continuous side-blowing furnace is directly converted into high nickel matte products, and the remaining 2 / 3 needs to be returned for re-blowing, which is inefficient. In addition, there is no external heat source in the iron-lifting furnace after the settling furnace, and the process of reducing iron silicate by the reducing agent is an endothermic reaction. The temperature of the electric furnace slag decreases during the reaction, the reaction rate is slow, and the iron recovery rate is low.
[0003] At present, there are several disadvantages in the recovery of hot slag of high nickel matte:
[0004] Disadvantages 1. The reduction of iron silicate in high nickel matte hot slag to metallic iron is an endothermic reaction, which requires an external heat source to support the reaction process. Otherwise, the iron recovery rate is low and the temperature of the recovered molten iron is too low for the steel mill to use directly.
[0005] Disadvantage 2: Due to process limitations, there is still a high content of metallic iron in the iron slag after iron extraction, and the iron slag is not effectively utilized.
[0006] Disadvantage 3: The existing high-grade nickel matte hot slag treatment requires more production equipment and a longer process flow. The high-grade nickel matte hot slag needs to be repeatedly blown in an oxygen-rich continuous side-blowing furnace.
[0007] Disadvantage 4. Sulfur is prone to hot brittle cracking during the hot processing of steel. During the production of high-grade nickel matte from low-grade nickel matte, a large amount of sulfur enters the hot slag of high-grade nickel matte. When reducing iron from the slag, a large amount of sulfur still enters the molten iron. If high-sulfur molten iron is used for steelmaking, the burden of steelmaking desulfurization will be increased, especially when producing ordinary carbon steel, as ordinary converters have no desulfurization capacity. Summary of the invention
[0008] The technical problem to be solved by the present invention is to provide a high-nickel matte production process and a high-nickel matte hot slag treatment method, which can improve the iron recovery rate in the iron extraction process, and enable the recovered molten iron to be directly utilized, and can reduce the proportion of high-nickel matte hot slag returned to the furnace, reduce repeated treatment processes and equipment, shorten the process flow, and improve production efficiency.
[0009] The present invention is achieved in that:
[0010] The present invention provides a high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method, comprising the following steps:
[0011] Step S1, using low-grade nickel matte cold material and low-grade nickel matte iron water as raw materials, using silica as a slag-making agent, and transporting them to a blowing furnace for smelting to produce high-grade nickel matte;
[0012] Step S2, dividing the high nickel matte smelting process into several different stages, and dividing the several different stages into a low nickel stage and a high nickel stage according to the percentage of nickel content in the discharged hot slag;
[0013] The hot slag in the high nickel stage is sent back to the converting furnace to continue refining high nickel matte;
[0014] The hot slag in the low-nickel stage is sent to the depletion electric furnace, and at the same time, a reducing agent and a flux are added into the depletion electric furnace to produce depleted molten iron containing nickel and chromium.
[0015] Furthermore, in the step S1, the blowing furnace is a first AOD furnace or a nickel converter.
[0016] Furthermore, in step S2, the reducing agent, flux and hot slag at the low nickel stage are calculated by mass percentage as follows: the reducing agent accounts for 5%-20%, the flux accounts for 15%-45%, and the rest is hot slag at the low nickel stage.
[0017] Furthermore, the reducing agent is reducing coal or ferrosilicon.
[0018] Furthermore, the flux is lime.
[0019] Furthermore, the depleted tailings discharged from the depleted electric furnace are sent to a mixer and mixed with cement clinker to produce concrete.
[0020] Furthermore, the nickel-chromium-containing depleted iron water is divided into two parts, one part is sent to the second AOD furnace to produce stainless steel, and the other part is sent to the cast iron machine to form breaded iron, and when the second AOD furnace needs to be supplemented with molten iron, the breaded iron is sent to the medium frequency furnace for heating, and the second AOD furnace is supplemented with molten iron in the form of red molten iron.
[0021] Furthermore, the smelting process of high nickel matte is divided into 12 stages, and as the stages gradually increase, the percentage of nickel content in the discharged hot slag also gradually increases, and stages 1-6 are low-nickel stages, and stages 7-12 are high-nickel stages.
[0022] The advantages of the present invention are: the present invention reduces the proportion of high-grade nickel matte hot slag returned to the furnace (in the prior art, all high-grade nickel matte hot slag needs to be returned to the furnace, while the amount of high-grade nickel matte hot slag returned to the furnace in the present invention is less than half), reduces repeated treatment processes and equipment, can shorten the process flow, and improve production efficiency. In addition, because the depletion furnace has an external heat source, the iron recovery rate in the slag is high during the iron extraction process. Moreover, due to the addition of lime, after the depletion furnace extracts iron, the depleted tailings can be mixed with cement clinker to be made into concrete for use.
[0023] The nickel-chromium-containing depleted iron water after iron extraction in the depleted electric furnace is sent to the second AOD furnace, which can recover the valuable metal elements such as iron, nickel and chromium in the high-nickel matte hot slag, and can also make full use of the waste heat of the nickel-chromium-containing depleted iron water. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.
[0025] Figure 1 The present invention provides a process flow chart of a high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method.
[0026] Figure 2 The present invention provides a comparison table of materials added at various stages, material adding temperatures, nickel content in the molten pool, and nickel content in the hot slag. DETAILED DESCRIPTION
[0027] See also Figure 1 to Figure 2 The present invention provides a high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method, comprising the following steps:
[0028] Step S1, using low-grade nickel matte cold material and low-grade nickel matte iron water as raw materials, using silica as a slag-making agent, and transporting them to a blowing furnace for smelting to produce high-grade nickel matte;
[0029] Step S2, dividing the high nickel matte smelting process into several different stages, and dividing the several different stages into low nickel stages and high nickel stages according to the percentage of nickel content in the discharged hot slag; more specifically, when the percentage of nickel content in the discharged hot slag is greater than 0.3%, it is the high nickel stage, and when it is less than or equal to 0.3%, it is the low nickel stage.
[0030] The hot slag in the high nickel stage is sent back to the converting furnace to continue refining high nickel matte;
[0031] The hot slag in the low-nickel stage is sent to the depletion electric furnace, and at the same time, a reducing agent and a flux are added into the depletion electric furnace to produce depleted molten iron containing nickel and chromium.
[0032] In the present invention, the smelting process of high nickel matte is divided into 12 stages. During the smelting process of high nickel matte, slag is not discharged continuously. Slag is discharged once after each stage. As the stages increase, the percentage of nickel content in the discharged hot slag also increases gradually. Stages 1 to 6 are low nickel stages, and stages 7 to 12 are high nickel stages. Figure 2 As shown, the nickel content in the hot slag of stages 1-6 is less than 0.3%.
[0033] In each of the 12 stages, three batches of materials are added successively. The materials added in each stage, the material addition temperature, the nickel content in the molten pool and the nickel content in the hot slag, such as Figure 2 By controlling the amount and temperature of materials added at each stage, the nickel content in the slag can be effectively controlled.
[0034] Take the production of 60-80 tons of high-grade nickel matte as an example:
[0035] Stages 1 to 6: The charging temperature of each stage is 1280℃, the first batch of materials is 2 tons of silica, the second batch of materials is 100-120 tons of low-grade nickel matte cold material, 30-50 tons of high-nickel blocks and 4 tons of silica, the third batch of materials is 4 tons of high-grade nickel matte slag and 2 tons of silica.
[0036] In the first stage, the nickel content in the molten pool was 18%, the nickel content in the hot slag was 0.177%, and the sulfur content was 2.56%;
[0037] In the second stage, the nickel content in the molten pool was 28%, the nickel content in the hot slag was 0.178%, and the sulfur content was 2.34%;
[0038] In the third stage, the nickel content in the molten pool is 37%, the nickel content in the hot slag is 0.179%, and the sulfur content is 2.15%;
[0039] In the fourth stage, the nickel content in the molten pool is 46%, the nickel content in the hot slag is 0.193% and the sulfur content is 1.97%;
[0040] In the fifth stage, the nickel content in the molten pool is 55%, the nickel content in the hot slag is 0.216%, and the sulfur content is 1.72%;
[0041] In the sixth stage, the nickel content in the molten pool is 60%, the nickel content in the hot slag is 0.248%, and the sulfur content is 1.44%;
[0042] Stage 7: The charging temperature is 1300℃, the first batch of materials is 2 tons of silica, the second batch of materials is 100-120 tons of low-grade nickel matte cold material, 30-50 tons of high-nickel blocks and 4 tons of silica, the third batch of materials is 4 tons of high-grade nickel matte slag and 2 tons of silica.
[0043] In the 7th stage, the nickel content in the molten pool is 63%, the nickel content in the hot slag is 0.455%, and the sulfur content is 0.93%.
[0044] Stages 8 to 12: The feeding temperature of each stage is 1300°C, the first batch of materials is 2 tons of silica, the second batch of materials is 10-12 tons of high-grade nickel slag (added twice) and 2 tons of silica, and the third batch of materials is 8-10 tons of high-grade nickel slag and 2 tons of silica.
[0045] In the eighth stage, the nickel content in the molten pool was 65%, the nickel content in the hot slag was 0.464%, and the sulfur content was 0.73%;
[0046] In the 9th stage, the nickel content in the molten pool was 67%, the nickel content in the hot slag was 0.826%, and the sulfur content was 0.6%;
[0047] In the 10th stage, the nickel content in the molten pool was 68%, the nickel content in the hot slag was 2.27%, and the sulfur content was 0.43%;
[0048] In the 11th stage, the nickel content in the molten pool was 69%, the nickel content in the hot slag was 2.93% and the sulfur content was 0.32%;
[0049] In the 12th stage, the nickel content in the molten pool is 70%, the nickel content in the hot slag is 3.12%, and the sulfur content is 0.27%.
[0050] Specifically, in step S1, the blowing furnace is a first AOD furnace or a nickel converter.
[0051] Specifically, in step S2, the reducing agent, flux and hot slag at the low nickel stage are calculated by mass percentage as follows: the reducing agent accounts for 5%-20%, the flux accounts for 15%-45%, and the rest is hot slag at the low nickel stage.
[0052] Specifically, the reducing agent is reducing coal or ferrosilicon. The addition of the reducing agent can reduce the iron in the hot slag at the low nickel stage to metallic iron, and the reducing atmosphere creates conditions for the desulfurization of molten iron. When the reducing coal required for the reaction is added, the carbon element enters the molten steel, lowering the liquidus temperature of the molten iron, facilitating the transfer and transportation of high-temperature molten iron, and providing a chemical heat source for steelmaking and smelting.
[0053] The present invention can use ferrosilicon as a reducing agent. Compared with reducing coal, the advantages of ferrosilicon as a reducing agent are as follows: no combustible gas, such as CO, is generated, so there is no need to collect and process CO in the tail gas, reducing equipment costs. No gas is generated, splashing in the iron-raising furnace can be avoided, and under the premise of improving production safety, the corrosion of the furnace lining caused by the churning of the molten pool due to the generation of CO and CO2 gases can also be reduced. The heat generated during the reaction of ferrosilicon with ferrous silicate or ferrous oxide is relatively high, which can reduce the power consumption by 40%.
[0054] Specifically, the flux is lime. Lime is added as a flux in the depletion furnace. The main function of lime is to reduce the melting point of the slag system and reduce the reaction enthalpy. At the same time, the addition of lime can reduce the sulfur in the molten iron to the slag, reducing the load of steelmaking desulfurization.
[0055] Specifically, the depleted tailings discharged from the depleted electric furnace are sent to a mixer and mixed with cement clinker to make concrete. Due to the addition of lime, the depleted tailings after iron extraction from the depleted electric furnace can be mixed with cement clinker to make concrete for use.
[0056] Specifically, the nickel-chromium-containing depleted iron water is divided into two parts, one part is sent to the second AOD furnace to produce stainless steel, and the other part is sent to the cast iron machine to form breaded iron. When the second AOD furnace needs to be supplemented with molten iron, the breaded iron is sent to the medium frequency furnace for heating, and the molten iron is supplemented to the second AOD furnace in the form of red molten iron.
[0057] The advantages of the present invention are: the present invention reduces the proportion of high-grade nickel matte hot slag returned to the furnace (in the prior art, all high-grade nickel matte hot slag needs to be returned to the furnace, while the present invention returns less than half of the high-grade nickel matte hot slag), reduces repeated processing processes and equipment, shortens the process flow, improves production efficiency, reduces production costs, and improves economic benefits. In addition, 300,000 to 500,000 tons of high-grade nickel matte slag can be discarded each year, reducing environmental pollution.
[0058] In addition, since the depletion furnace has an external heat source, the iron recovery rate in the slag during the iron extraction process is high. Moreover, due to the addition of lime, after the depletion furnace extracts iron, the depletion tailings can be mixed with cement clinker to make concrete.
[0059] The nickel-chromium-containing depleted iron water after iron extraction in the depleted electric furnace is sent to the second AOD furnace, which can recover the valuable metal elements such as iron, nickel and chromium in the high-nickel matte hot slag, and can also make full use of the waste heat of the nickel-chromium-containing depleted iron water.
[0060] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent substitutions and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.
Claims
1. A high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method, characterized in that: The steps include: Step S1, using low-grade nickel matte cold material and low-grade nickel matte iron water as raw materials, using silica as a slag-making agent, and transporting them to a blowing furnace for smelting to produce high-grade nickel matte; Step S2, dividing the high nickel matte smelting process into several different stages, and dividing the several different stages into a low nickel stage and a high nickel stage according to the percentage of nickel content in the discharged hot slag; The hot slag in the high nickel stage is sent back to the converting furnace to continue refining high nickel matte; The hot slag in the low-nickel stage is sent to the depletion electric furnace, and at the same time, a reducing agent and a flux are added into the depletion electric furnace to produce depleted molten iron containing nickel and chromium.
2. A high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method as claimed in claim 1, characterized in that: In the step S1, the blowing furnace is a first AOD furnace or a nickel converter.
3. A high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method as claimed in claim 1, characterized in that: In step S2, the reducing agent, flux and hot slag at the low nickel stage are calculated by mass percentage, wherein the reducing agent accounts for 5%-20%, the flux accounts for 15%-45%, and the rest is hot slag at the low nickel stage.
4. A high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method as claimed in claim 1, characterized in that: The reducing agent is reducing coal or ferrosilicon.
5. A high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method as claimed in claim 1, characterized in that: The flux is lime.
6. A high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method as claimed in claim 5, characterized in that: The depleted tailings discharged from the depleted electric furnace are sent to a mixer and mixed with cement clinker to produce concrete.
7. A high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method as claimed in claim 1, characterized in that: The nickel-chromium-containing depleted iron water is divided into two parts, one part is sent to the second AOD furnace to produce stainless steel, and the other part is sent to the cast iron machine to form breaded iron. When the second AOD furnace needs to be supplemented with molten iron, the breaded iron is sent to the medium frequency furnace for heating, and the second AOD furnace is supplemented with molten iron in the form of red molten iron.
8. A high-grade nickel matte production process and a high-grade nickel matte hot slag treatment method as claimed in claim 1, characterized in that: The smelting process of high-nickel matte is divided into 12 stages, and as the stages gradually increase, the percentage of nickel content in the discharged hot slag also gradually increases, and stages 1-6 are low-nickel stages, and stages 7-12 are high-nickel stages.