A method for reducing matte coating

Abstract

The present invention provides a method for reducing the matte coating, which comprises the following steps: S1. Mix silicate minerals and anthracite evenly as heat-insulating auxiliary materials, then add the heat-insulating auxiliary materials into a blowing tank, and evenly blow them into a matte ladle containing hot matte under an inert gas atmosphere; S2. Add different amounts of heat-insulating auxiliary materials according to the placement time of the converter, and the relationship between the addition amount of the heat-insulating auxiliary materials and the placement time is: 20-30 kg / h; By mixing anthracite and silicate minerals to insulate the hot matte, the present invention can move the starting point of crust formation backward on the time line after the hot matte is discharged, reduce the matte crusting speed, and reduce the output of matte coating.

Description

Technical Field

[0001] The present invention relates to the technical field of smelting, and more particularly, to a method for reducing the matte shell Background Art

[0002] In traditional smelters, Isa furnaces are generally equipped with a matte-leadening electric furnace. The hot matte is discharged from the electric furnace. Since a cold crust (matte shell) is easily formed on the surface of the hot matte quickly after it is discharged, after the charging of the converter is completed, it is necessary to clean and store the matte shell on the inner wall of the matte ladle. The matte shell is then returned as a raw material to the smelting process flow, resulting in an increase in the secondary smelting throughput. The handling, crushing, and smelting of the matte shell lead to an increase in the secondary processing cost.

[0003] To solve the problem of the matte shell, in the prior art, the hot matte is discharged from the electric furnace into the matte ladle and placed there, and then hoisted to the converter area according to production requirements and poured into the converter.

[0004] However, due to the rapid loss of the surface temperature of the hot matte and the fast formation rate of the crust; and due to the objective existence of the copper storage capacity limit of the electric furnace, there will be a long charging interval of more than half an hour between every two converter charges, resulting in the thickening of the matte crust and making it difficult to pour out the hot matte, and mechanical shell breaking is required. Therefore, during the process of hoisting the hot matte, the phenomenon of matte shell still inevitably exists. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for reducing the matte shell, which can thermally insulate the hot matte by mixing anthracite and silicate minerals, and can move the starting point of crust formation of the hot matte backward in the time line.

[0006] The embodiments of the present invention are implemented by the following technical solutions:

[0007] A method for reducing the matte shell includes the following steps:

[0008] S1. Mix silicate minerals and anthracite with a mass ratio of 1:2 - 5 evenly as a heat-insulating auxiliary material, then add the heat-insulating auxiliary material into a spray tank, and evenly spray it into the matte ladle containing hot matte under the atmosphere of a protective gas (a mixed gas of nitrogen and argon);

[0009] S2. Add different amounts of heat-insulating auxiliary material according to the placement duration of the converter. The relationship between the addition amount of the heat-insulating auxiliary material and the placement duration is: 20 - 30 kg / h.

[0010] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0011] 1. The present invention insulates and heat-preserves hot matte by mixing anthracite and silicate minerals, which can shift the starting point of crust formation backward in the time line after the release of hot matte, reduce the crusting speed of matte, and decrease the output of matte cladding.

[0012] 2. After adopting the method of the present invention, the monthly output of matte cladding is reduced by about 13%, reducing the output of intermediate products from the source; and the net weight of a single matte package can be increased by up to 2.9%, ensuring the feed quantity of the converter and reducing the secondary smelting cost of matte cladding by at least 1.3 million yuan per year. Specific Embodiment

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. For those not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are adopted. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0014] A method for reducing matte cladding provided by the embodiments of the present invention will be specifically described below.

[0015] A method for reducing matte cladding includes the following steps:

[0016] S1. Mix silicate minerals and anthracite with a mass ratio of 1:2 - 5 evenly as heat-preserving auxiliary materials. Preferably, the silicate minerals can be quartz sand with a particle size of 70 - 140 mesh. Then add the heat-preserving auxiliary materials into the injection tank and evenly spray them into the matte ladle containing hot matte under the atmosphere of protective gas (nitrogen and argon); in this way, a heat-preserving layer can be formed on the surface of hot matte. Anthracite burns and releases heat on the surface of the matte ladle, providing heat for heat-preserving the matte. Silicate minerals such as quartz sand float on the surface of the matte, forming a heat-insulating layer, and quartz sand does not react with the matte. Therefore, adding a mixture of quartz sand and anthracite as heat-preserving auxiliary materials can better delay the crusting speed of matte and reduce the output of matte cladding.

[0017] Preferably, when introducing the protective gas, the flow rate of the protective gas is controlled as follows: within the first 10 minutes, the flow rate of the protective gas is 20 - 50 mL / min; within 10 - 20 minutes, the flow rate of the protective gas is 50 - 100 mL / min; within 20 - 30 minutes, the flow rate of the protective gas is 100 - 150 mL / min;

[0018] By controlling the flow rate of the protective gas, the flow rate of the heat preservation auxiliary material sprayed into the matte ladle is further controlled, so that the anthracite is more stably coated on the surface of the hot matte, and the combustion heat release provides heat for the matte heat preservation, and the hot matte is always in the atmosphere created by the anthracite for repeated laminated coating. At the same time, the quartz sand is used repeatedly for heat insulation to form an isolation layer; in this way, a heating layer - isolation layer - heating layer with a multi-layer cross distribution can be formed; thus, a more stable isolation method is formed to reduce the matte crusting speed and reduce the output of the matte ladle shell.

[0019] S2. Add different amounts of heat preservation auxiliary materials according to the placement time of the converter (it should be noted that the discharge amount of each ladle of hot matte is about 17.5t). Specifically:

[0020] ① If the matte can be poured into the converter for production within 30 minutes after being discharged, add 10 - 15 kg of heat preservation auxiliary material when approaching the end of the furnace front discharge. Preferably, adding 15 kg of heat preservation agent can effectively reduce the formation of crust.

[0021] ② If the placement time of the matte is greater than 30 minutes and less than 1 hour, adding 20 - 30 kg of heat preservation auxiliary material when approaching the end of the furnace front discharge can effectively reduce the formation of crust.

[0022] ③ If the placement time of the matte is greater than 1 hour, add 15 - 25 kg of heat preservation auxiliary material when approaching the end of the furnace front discharge, and then add 5 - 15 kg of heat preservation auxiliary material 1 hour after the material is placed to delay the crust formation speed after the consumption of the heat preservation agent.

[0023] Due to the fluctuations in the on-site production rhythm, the placement time of each ladle of hot matte after being discharged is different, but the placement time is predictable. Therefore, it is necessary to determine the addition amount of the heat preservation auxiliary material according to the length of the placement time. Taking 10 minutes as the time interval, the crusting situation on the surface of the hot matte under different addition amounts of the heat preservation agent is experimentally analyzed as shown in Table 1 (the crust thickness takes the experimental average value):

[0024] Table 1

[0025]

[0026] Since it is necessary to ensure that the heat preservation agent can achieve the expected heat preservation effect on the surface of the hot matte heat preservation agent, the heat preservation agent needs to completely cover the surface of the matte to form an insulation layer. It can be seen from the above table that the usage amount of the heat preservation agent should not be less than 10 kg.

[0027] To further verify the effect of the matte heat preservation agent used in the present invention, a horizontal comparison of the heat preservation agent is carried out on the hot matte with a placement time of 30 - 60 minutes by adding the heat preservation agent. The results are shown in Table 2:

[0028] Table 2

[0029]

[0030] As can be seen from the data in Table 2, by adopting the method of the present invention, the thickness of the crust on the surface of hot matte is significantly reduced, and the crust formation rate is significantly decreased, reducing the output of intermediate products from the source.

[0031] Example 1

[0032] A method for reducing matte cladding, comprising the following steps:

[0033] S1. Mix quartz sand and anthracite with a mass ratio of 1:2 evenly as heat preservation auxiliary materials, then add the heat preservation auxiliary materials into the injection tank, and evenly inject them into the matte ladle containing hot matte under the protection atmosphere of a mixed gas of nitrogen and argon; when injecting the mixed gas: within the first 10 minutes, the protective gas flow rate is 30 mL / min; within 10 - 20 minutes, the protective gas flow rate is 60 mL / min; within 20 - 30 minutes, the protective gas flow rate is 120 mL / min;

[0034] S2. Pour it into the converter for production 23 minutes after the matte is discharged, and add 10 kg of heat preservation auxiliary materials when approaching the discharge end in front of the furnace.

[0035] Example 2

[0036] A method for reducing matte cladding, comprising the following steps:

[0037] S1. Mix quartz sand and anthracite with a mass ratio of 1:3 evenly as heat preservation auxiliary materials, then add the heat preservation auxiliary materials into the injection tank, and evenly inject them into the matte ladle containing hot matte under the nitrogen atmosphere; when injecting the mixed gas: within the first 10 minutes, the protective gas flow rate is 20 mL / min; within 10 - 20 minutes, the protective gas flow rate is 50 mL / min; within 20 - 30 minutes, the protective gas flow rate is 100 mL / min;

[0038] S2. Pour it into the converter for production 48 minutes after the matte is discharged, and add 20 kg of heat preservation auxiliary materials when approaching the discharge end in front of the furnace.

[0039] Example 3

[0040] A method for reducing matte cladding, comprising the following steps:

[0041] S1. Mix quartz sand and anthracite with a mass ratio of 1:4 evenly as heat preservation auxiliary materials, then add the heat preservation auxiliary materials into the injection tank, and evenly inject them into the matte ladle containing hot matte under the nitrogen atmosphere; when injecting the mixed gas: within the first 10 minutes, the protective gas flow rate is 45 mL / min; within 10 - 20 minutes, the protective gas flow rate is 80 mL / min; within 20 - 30 minutes, the protective gas flow rate is 140 mL / min;

[0042] S2. Pour the matte into the converter for production 71 minutes after it is discharged. Add 20 kg of heat preservation auxiliary materials when approaching the end of discharge in front of the furnace. Add another 10 kg of heat preservation auxiliary materials 1 hour after spreading the materials, with a total of 30 kg of heat preservation auxiliary materials.

[0043] Comparative Example 1

[0044] The difference between this comparative example and Example 1 is that no heat preservation auxiliary materials are added.

[0045] Experimental Example 1

[0046] Compare and analyze the discharge situation of the hot matte and the production situation of the cladding treated by the methods of Comparative Example 1 and Example 1. The results are shown in Table 3-4;

[0047] Among them, Table 3 shows the matte discharge situation without adding heat preservation auxiliary materials (i.e., Comparative Example 1) in 2021, and Table 4 shows the matte discharge situation with adding heat preservation auxiliary materials (i.e., Example 1) from April 2022 to March 2023.

[0048] Table 3

[0049]

[0050]

[0051] Table 4

[0052] Month Net Matte Quantity / t Number of Matte Packages / package Matte per Package / t April 20758 1183 17.5 May 20077 1152 17.4 June 20648 1186 17.4 July 16296 934 17.4 August 19586 1143 17.1 September 19811 1151 17.2 October 16075 906 17.7 November 19882 1142 17.4 December 25109 1443 17.4 January 16275 920 17.7 February 20761 1181 17.6 March 18147 1037 17.5 Average Value 19452.1 1115 17.5

[0053] It can be seen from the results in Table 3-4 that by adopting the method of the present invention, the net weight of a single package of matte is increased by about (17.5 - 17.0) / 17.0 = 2.9%. Under the condition of organizing production with the number of matte packages at present, the feeding amount of the converter is ensured.

[0054] Experimental Example 2

[0055] Compare and analyze the production situation of the cladding of the hot matte treated by the methods of Comparative Example 1 and Example 1. The results are shown in Table 5-6;

[0056] Among them, Table 5 shows the discharge situation of the cladding of the matte without adding heat preservation auxiliary materials (i.e., Comparative Example 1) from January to December 2021, and Table 6 shows the discharge situation of the cladding of the matte with adding heat preservation auxiliary materials (i.e., Example 1) from April 2022 to March 2023.

[0057] Table 5

[0058] Month Matte Package Shell / t Number of Matte Packages / package Matte Package Shell per Package / t January 1411 910 1.55 February 1925 1169 1.65 March 1637 1042 1.57 April 1840 1131 1.63 May 1744 1035 1.69 June 1984 1161 1.71 July 1133 1899 1.68 August 966 1562 1.62 September 1184 1988 1.68 October 1247 1981 1.59 November 1318 2366 1.80 December 662 1061 1.60 Average Value 1080 1783.2 1.651

[0059] Table 6

[0060]

[0061]

[0062] As can be seen from the data in Table 5-6: Through the treatment method of the present invention, the single-package output of the matte shell is reduced by about 1.651t - 1.435t = 0.216t. Calculated based on 1100 matte packages per month, the monthly output of the matte shell is reduced by about 0.216t * 1100 = 237.67t / month, and the reduction rate is 237.67 / 1783.2 = 13.3%.

[0063] Cost accounting:

[0064] ① The unit price of anthracite is 1750 yuan / t. Calculated based on the average addition amount of 20t of matte heat insulator per package, the addition amount of anthracite is 20 * t(2 / 3) = 13.33t. Then the monthly cost of anthracite is 13.33 * 1100 / 1000 * 1750 = 25,700 yuan / month;

[0065] ② The unit price of quartz sand is 95 yuan / t. Calculated based on the average addition amount of 20t of matte heat insulator per package, the addition amount of anthracite is 20 * t(1 / 3) = 6.67t. Then the monthly cost of anthracite is 6.67 * 1100 / 1000 * 95 = 700 yuan / month;

[0066] ③ The matte shell is processed through the return process of the smelting system, and the secondary processing cost is 1228.2 yuan / t. Taking the matte grade as 55%, the cost that can be saved is 237.67 * 55% * 1228.2 / 10000 - 2.57 - 0.07 = 134,100 yuan / month.

[0067] It can be seen from this that through the treatment method of the present invention, the smelting cost of the enterprise can be greatly reduced, bringing greater benefits to the enterprise.

[0068] The above is only the preferred embodiment of the present invention and is not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for reducing the matte coating, characterized in that, It includes the following steps: S1. Mix silicate minerals and anthracite evenly as heat-insulating auxiliary materials, then add the heat-insulating auxiliary materials into the injection tank, and evenly inject them into the matte ladle containing hot matte under the atmosphere of protective gas; S2. Add different amounts of heat-insulating auxiliary materials according to the placement time of the converter. The relationship between the addition amount of the heat-insulating auxiliary materials and the placement time is as follows: If the matte can be poured into the converter for production within 30 minutes after being discharged, add 10 - 15 kg of heat-insulating auxiliary materials when approaching the end of the furnace front discharge; if the matte placement time is greater than 30 minutes and less than 1 hour, add 20 - 30 kg of heat-insulating auxiliary materials when approaching the end of the furnace front discharge; if the matte placement time is greater than 1 hour, add 15 - 25 kg of heat-insulating auxiliary materials when approaching the end of the furnace front discharge, and then add 5 - 15 kg of heat-insulating auxiliary materials 1 hour after the placement.

2. The method for reducing the matte shell according to claim 1, wherein In S1, the mass ratio of the silicate minerals to the anthracite is 1:2 - 5.

3. The method for reducing the matte shell according to claim 2, wherein In S1, the particle size of the silicate minerals is 70 - 140 mesh.

4. The method for reducing the matte shell according to claim 1, wherein In S1, the protective gas is a mixed gas of nitrogen and argon.

5. The method for reducing the matte shell according to claim 4, characterized in that, In S1, when introducing the protective gas, the flow rate of the protective gas is controlled as follows: within the first 10 minutes, the flow rate of the protective gas is 20 - 50 mL / min; within 10 - 20 minutes, the flow rate of the protective gas is 50 - 100 mL / min; within 20 - 30 minutes, the flow rate of the protective gas is 100 - 150 mL / min.

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