A method for non-carbon copper smelting with high oxygen enrichment and non-linear strengthening

Abstract

The present invention discloses a method for non-carbon copper smelting with high oxygen enrichment and non-linear strengthening, belonging to the technical field of copper smelting. The method for non-carbon copper smelting with high oxygen enrichment and non-linear strengthening comprises the following steps: through ore blending, adjusting the sulfur-copper ratio of copper concentrate to 1.1-1.8, and then through premixing with flux, adjusting the mass ratio of Fe to SiO2 to 1.0-2.0 to obtain a premixed material; subjecting the premixed material to non-linear strengthening smelting under the condition of oxygen-enriched air to obtain matte, slag and flue gas; during the non-linear strengthening smelting process, no carbonaceous fuel is added. The present invention makes reasonable batching according to the composition differences of various copper concentrates and limits the sulfur-copper ratio in the mixed copper concentrate, so that a violent oxidation reaction occurs between sulfides and high oxygen-enriched air during the smelting process, releasing high-energy heat, thereby avoiding the use of carbonaceous fuel and carbon dioxide emission during the smelting process.

Description

Technical Field

[0001] The present invention relates to the technical field of copper smelting, and particularly relates to a method for non-carbon copper smelting with high oxygen enrichment and non-linear strengthening. Background Art

[0002] At present, as one of the important pillars of the economic society, the non-ferrous metal industry still needs to continuously improve and upgrade green and low-carbon technologies as the requirements for environmental protection and energy consumption increase worldwide.

[0003] In current various copper smelting processes, whether it is flash smelting or bath smelting, during the matte smelting process, an appropriate amount of fuel needs to be added to meet the heat balance requirements of the smelting process and ensure the smooth progress of production. Although through continuous technological upgrades, the proportion of fuel added during the smelting process has gradually decreased, the carbon dioxide content emitted by it is still not negligible. Therefore, there is an urgent need for a method to reduce the carbon dioxide emissions during copper smelting. Summary of the Invention

[0004] In view of the problems of high coal blending rate and large amount of CO2 gas emissions during the copper smelting process in the prior art, the present invention provides a method for non-carbon copper smelting with high oxygen enrichment and non-linear strengthening.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention: Provide a method for non-carbon copper smelting with high oxygen enrichment and non-linear strengthening, including the following steps:

[0007] Through ore blending, adjust the sulfur-copper ratio of copper concentrate to 1.1 - 1.8, and then through premixing with flux, adjust the mass ratio of Fe to SiO2 to 1.0 - 2.0 to obtain a premixed material;

[0008] Carry out non-linear strengthening smelting on the premixed material under the condition of oxygen-enriched air to obtain matte, slag and flue gas;

[0009] During the non-linear strengthening smelting process, no carbonaceous fuel is added.

[0010] Preferably, the non-linear strengthening smelting is carried out in a chaotic stirring bath at a temperature of 1180 - 1240 °C.

[0011] More preferably, the specific operation of the non-linear strengthening smelting is: blow the oxygen-enriched air into the bath at an angle of 90 - 120 ° to drive the uniform agitation of the melt; detect the temperature difference of the bath furnace body, and if the temperature difference is greater than ±10 °C, instantaneously adjust the flow rate of the oxygen-enriched air to make the melt transfer heat uniformly.

[0012] The angle of the oxygen-enriched air in the present invention refers to the angle between the gas entering the melt and the melt surface.

[0013] Preferably, the volume concentration of oxygen in the oxygen-enriched gas is 65% - 75%.

[0014] Preferably, after the non-linear enhanced smelting, it further includes a flue gas post-treatment step, specifically: converting the SO2 gas in the flue gas into elemental sulfur and then returning it as a return material to the ore blending step.

[0015] Preferably, the ore blending is specifically: using a genetic particle swarm optimization algorithm for multi-objective programming for precise batching. By adding fluxes, return materials, and different types of copper concentrates, the premix contains the following chemical components in mass percentages: Cu 17 - 25%, Fe 15 - 25%, S 18 - 30%, CaO 1 - 5%, SiO2 5 - 20%, and Al2O3 1 - 5%.

[0016] Using a genetic particle swarm optimization algorithm for multi-objective programming for precise batching of multiple copper concentrates can better reduce experimental errors.

[0017] More preferably, the flux is quartz sand and CaO.

[0018] Preferably, the particle size of the premix is 0.1 - 1 mm.

[0019] Preferably, in the step of putting into the chaotic stirring molten bath, each raw material is fed through 2 - 4 feeding ports.

[0020] The raw materials fed into the furnace are dispersed into the molten bath through the feeding ports, and a better continuous dispersion effect can be obtained.

[0021] In the non-linear enhanced smelting process of the present invention, the following chemical reactions occur:

[0022] ① Combustion exothermic reaction:

[0023] 4CuFeS2 = 2Cu2S + 4FeS + S2

[0024] 2FeS2 = 2FeS + S2

[0025] 2FeS2 + 5O2 = 2FeO + 4SO2

[0026] 4FeS2 + 11O2 = 11FeO + 8SO2

[0027] 3FeS + 5O2 = Fe3O4 + 3SO2

[0028] 3Fe3O4 + FeS + 5SiO2 = 5(2FeO·SiO2) + SO2

[0029] S2 + 2O2 = 2SO2

[0030] ② Reduction reaction:

[0031] S2 + 4FeO = Fe + 2SO2

[0032] S2 + 4Fe3O4 = 12FeO + 2SO2

[0033] FeS2 + 5Fe3O4 = 16FeO + 2SO2

[0034] FeS + 3Fe3O4 = 10FeO + SO2

[0035] The beneficial technical effects of the present invention are as follows:

[0036] In the traditional Teniente copper smelting method, although it is close to self-heating during the reaction process, there is still a problem of insufficient heat, and it is necessary to add carbonaceous fuel; moreover, the carbonaceous fuel not only provides energy, but also plays roles such as a reducing agent during the reaction process. Therefore, there is still no solution in the prior art that completely omits fuel. The present invention makes reasonable batching according to the differences in the components of various copper concentrates and limits the sulfur-copper ratio in the mixed copper concentrates, so that the sulfide can undergo a violent oxidation reaction with high-enriched oxygen air during the smelting process, releasing high-energy heat, thereby avoiding the use of carbonaceous fuel and carbon dioxide emissions during the smelting process. At the same time, due to the uniform agitation of the melt, the sulfur source in the raw materials is more fully utilized, and sufficient reaction heat is released, thus better supplementing the energy gap during the smelting process, and therefore avoiding the addition of carbonaceous fuel.

[0037] During the smelting process, the sulfide undergoes a reduction reaction with Fe3O4 in the slag, reducing the content of Fe3O4 in the slag, thereby avoiding the formation of foamy slag during the production of high-grade matte. Finally, the grade of the matte can be increased to 70 - 78%, the copper content in the slag is <2.5%, and the content of Fe3O4 in the slag is <28%.

[0038] The present invention can produce high-grade matte, slag and flue gas through high-enriched oxygen non-linear enhanced injection chaotic stirring bath smelting. During the non-linear enhanced smelting process, the present invention strengthens the mass transfer and heat transfer between phases and accelerates the oxidation-reduction reaction rate by regulating the flow rate of enriched oxygen air in real time according to the temperature difference, thereby achieving the purpose of shortening the smelting time and improving the smelting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is the process flow chart of Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0040] Now, various exemplary embodiments of the present invention will be described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and implementation schemes of the present invention. It should be understood that the terms described in the present invention are only used to describe specific implementation modes and are not used to limit the present invention.

[0041] In addition, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Intermediate values within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, are also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0042] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention.

[0043] Regarding the use of "comprising", "including", "having", "containing", etc. in the present invention, they are all open-ended terms, meaning including but not limited to.

[0044] In the following examples of the present invention, the recycled materials used are all prepared by post-treating flue gas. Specifically, after the non-linear enhanced smelting is completed, the SO2 gas in the flue gas is converted into elemental sulfur and then returned to the ore blending step as a recycled material for addition.

[0045] The fluxes used in the following examples of the present invention are quartz sand and CaO.

[0046] The particle size of the premix used in the following examples of the present invention is 0.1 - 1 mm.

[0047] All raw materials used in the following examples of the present invention are commercially available products.

[0048] Example 1

[0049] (1) Using a genetic particle swarm optimization algorithm for multi-objective programming for precise batching, by adjusting the mass ratios of copper concentrate, flux, and recycled material, the chemical composition of the furnace charge premix is controlled to include the following mass percentages: Cu 21.66%, Fe 23.2%, S 24.5%, Pb 0.83%, Zn 2.18%, SiO2 16.57%, CaO 1.7%, and Al2O3 2.3%; the particle size of the furnace charge copper concentrate is 0.3 mm, and the moisture content is 3.51%.

[0050] (2) Feed the premix into the chaotic stirring smelting bath from two feeding ports, and blow oxygen-enriched air with a volume concentration of 66% and an angle of 96° at 1218°C to drive the uniform agitation of the melt. During this period, control the temperature difference by detecting the temperatures at multiple positions of the smelting bath furnace body. If the temperature difference is greater than ±10°C, instantaneously adjust the flow rate of the oxygen-enriched air to enable uniform heat transfer of the melt. After the reaction until the copper content in the matte is greater than 68%, produce matte, slag, and flue gas; among them, the matte contains the following chemical components by mass percentage: Cu 69.29%, S 18.60%, Fe 3.64%, and the slag contains the following chemical components by mass percentage: Fe 39.62% (wherein, Fe3O4 is 27.4%), Cu 2.36%, CaO 4.2%, SiO2 24.3%, Al2O3 3.5%.

[0051] (3) Further blow the matte to blister copper; recover the waste heat of the flue gas through a boiler and recover volatile valuable components such as zinc and lead through electrostatic precipitation, and convert the SO2 gas therein into elemental sulfur for recycling in the smelting system; further impoverish and magnetic separate the slag and use it as a building auxiliary material. The process flow chart is shown in Figure 1 (The post-treatment steps of the matte, slag, and flue gas are carried out according to the corresponding content recorded in "Modern Copper Metallurgy").

[0052] Example 2

[0053] (1) Use the genetic particle swarm optimization algorithm for multi-objective programming to accurately proportion the materials. By adjusting the mass ratios of copper concentrate, flux, and return material, control the chemical composition of the premix charged into the furnace to include the following by mass percentage: Cu 20.53%, Fe 24.5%, S 26.32%, Pb 0.75%, Zn 2.64%, SiO2 13.61%, CaO 2.7%, and Al2O3 3.3%; the particle size of the copper concentrate charged into the furnace is 0.5 mm, and the moisture content is 5.4%.

[0054] (2) Feed the premix into the chaotic stirring smelting bath from three feeding ports, and blow oxygen-enriched air with a volume concentration of 70% and an angle of 109° at 1228°C to drive the uniform agitation of the melt. During this period, control the temperature difference by detecting the temperatures at multiple positions of the smelting bath furnace body. If the temperature difference is greater than ±10°C, instantaneously adjust the flow rate of the oxygen-enriched air to enable uniform heat transfer of the melt. After the reaction until the copper content in the matte is greater than 70%, produce matte, slag, and flue gas; among them, the matte contains the following chemical components by mass percentage: Cu 72.13%, S 18.49%, Fe 2.64%, and the slag contains the following chemical components by mass percentage: Fe 38.52% (wherein, Fe3O4 is 26.14%), Cu 2.03%, CaO 3.16%, SiO2 24.98%, Al2O3 3.83%.

[0055] (3) The matte is further blown to blister copper; the flue gas recovers waste heat through a boiler and recovers volatile valuable components such as zinc and lead through electrostatic precipitation, and converts the SO2 gas therein into sulfur for recycling in the smelting system; the slag is further depleted and subjected to magnetic separation and then used as building auxiliary materials.

[0056] Example 3

[0057] (1) The genetic particle swarm optimization algorithm is used for multi-objective programming for precise batching. By adjusting the mass ratio of copper concentrate, flux and return material, the chemical composition of the pre-mixed material charged into the furnace is controlled to include the following mass percentages: Cu 19.53%, Fe 24.6%, S 28.15%, Pb 1.33%, Zn 3.68%, SiO2 12.6%, CaO 3.45% and Al2O3 2.1%; the particle size of the copper concentrate charged into the furnace is 0.8 mm and the moisture content is 7.4%.

[0058] (2) The pre-mixed material is fed into the chaotic stirring molten bath from 3 feeding ports, and oxygen-enriched air with a volume concentration of 75% and an angle of 94° is blown at 1237 °C to drive the uniform agitation of the melt. During this period, the temperature difference is controlled by detecting the temperatures at multiple positions of the molten bath furnace body. If the temperature difference is greater than ±10 °C, the flow rate of the oxygen-enriched air is instantaneously adjusted to make the melt transfer heat evenly. After the reaction until the copper content in the matte is greater than 70%, matte, slag and flue gas are produced; among them, the matte contains the following mass percentage of chemical composition: Cu 74.89%, S 18.13%, Fe 1.34%, and the slag contains the following mass percentage of chemical composition: Fe 37.96% (wherein, Fe3O4 is 23.78%), Cu 1.94%, CaO 5.84%, SiO2 25.10%, Al2O3 4.05%.

[0059] (3) The matte is further blown to blister copper; the flue gas recovers waste heat through a boiler and recovers volatile valuable components such as zinc and lead through electrostatic precipitation, and converts the SO2 gas therein into sulfur for recycling in the smelting system; the slag is further depleted and subjected to magnetic separation and then used as building auxiliary materials.

[0060] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for non-carbon copper smelting with high oxygen enrichment and non-linear strengthening, characterized in that The steps are as follows: Through ore blending, adjust the sulfur-copper ratio of copper concentrate to 1.1 - 1.8, and adjust the mass ratio of Fe to SiO2 to 1.0 - 2.0 to obtain a premix; Carry out non-linear enhanced smelting on the premix under the condition of oxygen-enriched air to obtain matte, slag and flue gas; During the non-linear enhanced smelting process, no carbonaceous fuel is added; The specific operation of the non-linear enhanced smelting is as follows: blow the oxygen-enriched air into the molten bath at an angle of 90 - 120° to drive the uniform agitation of the melt; detect the temperature difference of the molten bath furnace body, and if the temperature difference is greater than 10°C, instantaneously adjust the flow rate of the oxygen-enriched air to make the melt transfer heat uniformly; The non-linear enhanced smelting is carried out in a chaotic stirring molten bath at a temperature of 1180 - 1240°C; The specific ore blending is as follows: adopt a genetic particle swarm optimization algorithm for multi-objective programming for precise batching, and by adding fluxes, return materials and different types of copper concentrates, make the premix contain the following chemical components by mass percentage: Cu 17 - 25%, Fe 15 - 25%, S 18 - 30%, CaO 1 - 5%, SiO2 5 - 20% and Al2O3 1 - 5%; The angle is the angle when the gas is blown into the molten bath and the molten bath surface.

2. The method according to claim 1, wherein The volume concentration of oxygen in the oxygen-enriched air is 65% - 75%.

3. The method according to claim 1, characterized in that After the non-linear enhanced smelting is completed, it also includes a flue gas post-treatment step, specifically: convert the SO2 gas in the flue gas into elemental sulfur and then return it to the ore blending step as a return material addition.

4. The method according to claim 1, wherein The flux is quartz sand and CaO.

5. The method according to claim 1, characterized in that, The particle size of the premix is 0.1 - 1mm.

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