A method for protecting a copper converter

Abstract

The application provides a PS converter copper smelting protection method, relates to the technical field of converter maintenance process, and solves the technical problems of limited effect of the existing method for reducing the erosion of the converter lining and the introduction of other impurity ions for the PS converter copper smelting. The application comprises the following steps: step one, classifying the anode furnace returned slag and the converter decanting slag in hot and cold states; step two, crushing the cold material part obtained in the step one classification, uniformly mixing the crushed cold material with calcium oxide to obtain a cold material package; step three, adding the cold material package prepared in the step two into the converter during copper production; and step four, controlling the Fe3O4 in the anode furnace returned slag and the converter decanting slag to adhere to the inner wall of the converter. Through the adhesion of Fe3O4 to the furnace brick and the re-melting of copper in the waste slag into the copper phase, the service life of the converter can be effectively prolonged, and the metal recovery rate is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of converter maintenance process, in particular to a PS converter copper smelting protection method. BACKGROUND

[0002] In copper pyrometallurgical process, converter blowing is a necessary link of copper smelting process. The PS converter is the main metallurgical equipment in the copper smelting and blowing process, mainly including base, transmission system, converter body and other auxiliary equipment, and the converter body lining is built by magnesia-chrome refractory material. Magnesia-chrome refractory material is a kind of refractory material taking magnesia as the main material and taking chromite as the auxiliary material. The three main factors affecting the service life of the magnesia-chrome refractory material of the PS converter are chemical corrosion, thermal action and mechanical damage. In the blowing and slagging process of the PS converter, the erosion and washing of the converter lining, especially the tuyere area, are more serious, which leads to low converter service life, frequent converter repair, large consumption of refractory materials, high brick consumption per ton of copper and other problems. The thin tuyere area of the converter in the multi-converter period causes a large number of tuyere blockage, and even a large area of copper leakage in the tuyere area, which leads to unplanned shutdown and seriously affects the whole process production.

[0003] A method for reducing the erosion of the converter lining provided in the patent with publication number CN108330243A reduces the TFe content in the final slag by using dolomite slagging and adding converter waste slag to replace part of the metallurgical auxiliary materials, significantly reduces the erosion rate of the converter lining, improves the service life of the converter, and does not affect the smelting effect. By reducing the TFe content, the reaction of FeO with alumina and magnesia in the alumina-magnesia-carbon brick is reduced, which erodes the converter lining. However, the reaction of magnesium oxide and carbon in the alumina-magnesia-carbon brick generates a large amount of gas, which is the main reason for the damage of the magnesia-carbon brick. Moreover, for PS converter copper smelting, the main cause of the damage to the converter lining is still the low grade of the copper blister, the high proportion of cold materials in the slagging period, the poor slag type and high viscosity, the limited effect of reducing the total iron content on reducing the erosion, and the introduction of other impurity ions. SUMMARY

[0004] The present application aims to provide a PS converter copper smelting protection method to solve the technical problems of limited effect of the existing method for reducing the erosion of the converter lining and the introduction of other impurity ions for PS converter copper smelting.

[0005] The embodiments of the present application are implemented by the following technical solutions:

[0006] A PS converter copper smelting protection method, comprising the following steps:

[0007] Step one: classify the anode furnace returned slag and the converter decanting slag in hot and cold states;

[0008] Step two: the classified cold material part in step one is crushed, and the crushed cold material is mixed with the bulk calcium oxide to obtain a cold material package;

[0009] Step three: the cold material package obtained in step two is added into the converter during copper making;

[0010] Step four: the Fe3O4 in the anode furnace return slag and the converter slag is controlled to be as much as possible to be adhered to the inner wall of the converter, so that the Fe3O4 slag layer adhered to the surface of the refractory bricks in each region is ensured.

[0011] According to the technical scheme, the Fe3O4 and Cu with high content in the anode furnace return slag and the converter slag are recovered and added into the converter during copper making, the cold material can absorb the heat of the white copper melt, the temperature during copper making is controlled to be lower than 1190℃, the damage of high temperature to the furnace bricks is slowed down, the copper enters the liquid copper phase, the loss of copper metal inclusions into the converter slag is reduced, the direct recovery rate of copper metal is improved, the Fe3O4 slag is floated on the surface of the copper liquid, the Fe3O4 slag is blown and adhered to the furnace bricks in the tuyere region during the blowing process, the bulk calcium oxide is used, the calcium oxide particles with small particle size are prevented from being sucked into the flue or floating on the surface of the furnace by the negative pressure during the blowing process, the addition of calcium oxide can slow down the erosion of the acidic environment caused by SiO2 to the refractory bricks at high temperature, the residual SiO2 in the furnace is neutralized, the generated calcium silicate is a strong base weak acid salt which does not damage the furnace lining refractory, the furnace bricks are protected, and the service life of the converter is prolonged.

[0012] Preferably, in step one, the Cu accounts for 30wt%-50wt% in the anode furnace return slag, and the Fe3O4 accounts for 5wt%-10wt%; the Cu accounts for 25wt%-45wt% in the converter slag, and the Fe3O4 accounts for 20wt%-50wt%; the mass ratio of the anode furnace return slag to the converter slag is 3-1:1.

[0013] According to the technical scheme, the copper content and high-valence iron in the recycled anode furnace return slag and converter slag are ensured to be in a suitable range to meet the corresponding recycling requirements. Preferably, in step two, the cold material part is a high-copper high-valence iron material, which is crushed to obtain bulk oxidized cold material with a particle size of about 400-500mm, and the bulk oxidized cold material is mixed with bulk calcium oxide with a particle size of 50mm to obtain a cold material package.

[0014] According to the technical scheme, the high-copper high-valence iron material is crushed to a suitable particle size and mixed with calcium oxide to ensure that the two are mixed sufficiently, and the bulk calcium oxide with a particle size of 50mm is used to prevent the calcium oxide particles with small particle size from being sucked into the flue or floating on the surface of the furnace by the negative pressure during the blowing process, and the cold material with a particle size of 400mm is convenient for crushing by using the existing equipment on site and can well absorb the heat during copper making.

[0015] Preferably, in the second step, the crushed cold material is mixed with the bulk calcium oxide at a ratio of 6-10:1 to obtain a cold material package.

[0016] According to the technical scheme, the calcium oxide is added to react as follows: CaO+SiO2=CaSiO3, the calcium oxide reacts with the silicon dioxide (quartz solvent is added in the slagging period) to generate calcium silicate, and the erosion of the converter in the acidic environment is slowed down.

[0017] Preferably, in the third step, the material in the converter is generally 90t, the cold material package is added in an amount of 9-10t, and the mass ratio of the cold material package to the material in the converter is 9-10:1.

[0018] According to the technical scheme, 9t of cold material is added, the material in the converter during the copper-making period is about 90t, and the mass ratio of the cold material addition amount to the material in the converter is about 1:10. Under the premise that the cold material addition amount can control the temperature of the white copper melt within a suitable range, as much cold material as possible is added to increase the Fe3O4 blowing thickness and the copper recovery rate. 3 Preferably, in the fourth step, the blowing air volume is controlled to be 20000-22000Nm 3 / h, and the air pressure is controlled to be 0.07-0.08MPa.

[0019] According to the technical scheme, sufficient air volume is ensured to blow the Fe3O4 molten slag to the furnace bricks in the tuyere and other regions, so as to play a furnace protection effect.

[0020] Preferably, in the fourth step, when the blowing air volume is lower than 20000Nm 3 / h, the PS converter air hole is punched and cleaned to ensure smooth air supply.

[0021] According to the technical scheme, when the air hole of the converter is blocked, the air hole is cleaned to keep the air supply smooth and the air volume sufficient, so that the Fe3O4 molten slag can be blown to the furnace bricks in the tuyere and other regions.

[0022] Preferably, in the first step, the hot-state material in liquid state and the cold material in solid state are separated by a metallurgical crane.

[0023] According to the technical scheme, after the hot and cold states are classified, the cold-state high-copper high-valence iron part directly enters the furnace mouth machine for crushing, and the hot-state material is cooled and then processed.

[0024] Preferably, in the second step, the classified cold material is crushed by a furnace mouth machine.

[0025] According to the technical scheme, the on-site crushing is easy and convenient to operate.

[0026] The technical scheme of the embodiment of the application has at least the following advantages and beneficial effects:

[0027] 1. The cold material is added to the copper-making period of the furnace, which can absorb the heat of the white copper melt, and slow down the damage of high temperature to the furnace brick;

[0028] 2. The cold material is added to the copper-making period of the furnace, and the copper in it enters the liquid copper phase, reducing the loss of copper metal inclusions to the converter slag, and improving the direct recovery rate of copper metal;

[0029] 3. In the blowing process, the Fe3O4 slag is blown to the furnace bricks in the tuyere area, protecting the furnace bricks and prolonging the service life of the converter;

[0030] 4. The addition of calcium oxide can slow down the erosion of the acidic environment caused by SiO2 at high temperature on the refractory of the converter, and neutralize the residual silicon dioxide in the furnace for one period. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0032] Figure 1 The process flow diagram of the furnace protection method for PS converter copper smelting provided in Embodiment 1. DETAILED DESCRIPTION

[0033] Embodiment 1

[0034] A furnace protection method for PS converter copper smelting, comprising the following steps:

[0035] Step one: hot and cold classification of anode furnace return slag and converter decanting slag is carried out by metallurgical crane;

[0036] Step two: the cold material part obtained by classification in step one is crushed to 400mm by a furnace mouth machine, and the crushed cold material is mixed with blocky calcium oxide with a particle size of 50mm at a ratio of 8:1 to obtain a cold material package;

[0037] Step three: 9t of the cold material package prepared in step two is added to the furnace during copper-making period;

[0038] Step four: the blowing air volume is controlled to be 22000Nm 3 / h, and the air pressure is 0.07MPa, so that Fe3O4 in the anode furnace return slag is as much as possible to be hung on the furnace bricks in the tuyere area, and the Fe3O4 slag layer attached to the surface of the refractory bricks in each area is ensured.

[0039] In this embodiment, the anode furnace return slag and the converter decanting slag are sampled and analyzed for their chemical quality, and the main component contents are shown in Table 1.

[0040] Table 1. Main component content of anode furnace slag and converter slag

[0041]

[0042] By adopting the technical scheme, Fe3O4 and Cu with relatively high content in the cold charge of the anode furnace slag and the converter slag are recovered and added to the converter during copper making. The cold charge can absorb the heat of the white copper melt, control the temperature during copper making to be lower than 1190℃, slow down the damage of high temperature to the furnace brick; and the cold charge is added to the furnace during copper making, in which the copper enters the liquid copper phase, reduces the loss of copper metal inclusions into the converter slag, and improves the direct recovery rate of copper metal; and the molten slag (including Fe3O4) is floated on the surface of the copper liquid, and the Fe3O4 slag is blown and hung on the furnace brick in the tuyere area during the blowing process; the addition of calcium oxide can slow down the erosion of the acidic environment caused by SiO2 to the converter refractory at high temperature, neutralize the residual silicon dioxide in the furnace during one cycle, and the generated calcium silicate is a strong alkali weak acid salt which does not damage the furnace lining refractory, protects the furnace brick, and prolongs the service life of the converter.

[0043] In the embodiment, the service life of the converter and the maintenance frequency during the minor repair are estimated by recording the erosion and wear degree of the relevant furnace brick through multiple productions, and the final metal recovery rate is calculated.

[0044] Example 2

[0045] The difference between the embodiment and example 1 is only that in step four of the embodiment: the blowing air volume is controlled to be 20000 Nm 3 / h, and the air pressure is 0.08 MPa.

[0046] Example 3

[0047] The difference between the embodiment and example 1 is only that in step two of the embodiment, the cold charge is crushed to 500 mm by the furnace mouth machine, and the crushed cold charge and the blocky calcium oxide with a particle size of 50 mm are fully mixed in a proportion of 10:1 to prepare a cold charge package.

[0048] Example 4

[0049] The difference between the embodiment and example 1 is only that in step three of the embodiment, 9t of the cold charge package is added to the converter during copper making.

[0050] Comparative Example 1

[0051] The difference between the embodiment and example 1 is only that in the embodiment, the existing slag treatment is adopted, and the slag is not reused to participate in copper making and blowing during copper making and furnace protection.

[0052] Table 2. Estimated maintenance period and metal recovery rate of each example and comparative example

[0053]

[0054] As shown in Table 2, by the application of the furnace protection method of the present application, the converter maintenance cycle can be effectively reduced, and the maintenance frequency can be reduced. According to the statistical data: 1 time of intermediate repair (refractory cost about 1 million, furnace construction cost about 220,000, and furnace heating cost about 40,000 / time), 4 times of minor repair (refractory cost about 200,000 / time, furnace construction cost about 100,000 / time, and furnace heating cost about 35,000 / time), and the total cost of a major repair cycle is about 2.6 million. Compared with Comparative Example 1, the average minor repair furnace life of the converter of Example 1 is increased from 210 to 300 heats, and the furnace-related cost is reduced from 2476 yuan / heat to 1925 yuan / heat. According to the production of 80 tons of crude copper per furnace, the furnace-related cost per ton of copper is reduced from 30.95 yuan / t-Cu to 24.06 yuan / t-Cu.

[0055] According to the smelting plant of Liangshan Mining Industry Co., Ltd., there are three PS converters, and the annual production of qualified anode copper is 119,000 tons, and the direct yield of crude copper to qualified anode copper is 83%. Therefore, the annual production of crude copper is 143,300 tons.

[0056] The benefit generated by the increase of the converter life is 143.3 x (30.95-24.06) = 98 (million yuan / year).

[0057] At the same time, the annual production of converter slag is about 70,000 tons, and the copper content of the converter slag in the cold state is reduced from 6.5% to 3.4%. The calculation (3.1% x 70,000) x the processing cost of 1 ton of copper (1766 yuan / t-copper) generates a benefit of about 383.2 million yuan.

[0058] It can be seen that the furnace protection method proposed in the present application improves the metal recovery rate and reduces the converter maintenance cost and saves manpower and material resources by recycling waste slag.

[0059] More specifically, compared with Example 1, Example 2 adopts a low air pressure and high air volume state, which enhances the wind force washing the PS converter lining and has a certain influence on the adhesion of Fe3O4, so the furnace protection effect and metal recovery rate of Example 2 are lower than those of Example 1.

[0060] Example 3 increases the particle size of the anode furnace returned slag and the converter decanting slag, and under the same addition amount, the surface area of the anode furnace returned slag and the converter decanting slag is greatly reduced, which affects the dissolution of Fe3O4 and Cu, so the furnace protection effect and metal recovery rate of Example 3 are lower than those of Example 1.

[0061] Example 4 increases the addition amount of the cold charge, and the converter copper-making period material is generally 90 tons, and the ratio of the cold charge to the furnace material is increased from 1:10 to 1:9, that is, the content of Fe3O4 and Cu is correspondingly reduced, so the furnace protection effect and metal recovery rate of Example 4 are lower than those of Example 1.

[0062] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method of protecting a copper converter during the copper smelting process in a PS converter, characterized in that: The method comprises the following steps: Step 1: hot and cold classification of anode furnace return slag and converter slag; Step 2: crushing the cold material part obtained in step 1, mixing the crushed cold material with calcium oxide to obtain a cold material package; Step 3: adding the cold material package obtained in step 2 into the converter during copper making; Step 4: controlling Fe3O4 in the anode furnace return slag and the converter slag to adhere to the inner wall of the converter.

2. A method of protecting a PS converter for copper smelting according to claim 1, characterized in that: In step 1, the anode furnace return slag contains 30wt%-50wt% of Cu and 5wt%-10wt% of Fe3O4; the converter slag contains 25wt%-45wt% of Cu and 20wt%-50wt% of Fe3O4; and the mass ratio of the anode furnace return slag to the converter slag is 3-1:

1.

3. A method of protecting a PS converter for copper smelting according to claim 1 or 2, characterized in that: In step 2, the cold material part is crushed to obtain cold material with a particle size of 400-500mm, which is mixed with 50mm calcium oxide blocks to obtain a cold material package.

4. The method of claim 1 or 2, wherein the method is a method of protecting a copper converter. In step 2, the crushed cold material is mixed with calcium oxide at a mass ratio of 6-10:1 to obtain a cold material package.

5. A method of protecting a PS converter for copper smelting according to claim 1 or 2, characterized in that: In step 3, the mass ratio of the cold material package to the material in the converter is 9-10:

1.

6. A method of protecting a PS converter for copper smelting according to claim 1 or 2, characterized in that: In the fourth step, the amount of blowing air is controlled at 20,000-22,000 Nm 3 / h, and the air pressure is controlled at 0.07-0.08 MPa.

7. A method of protecting a PS converter for copper smelting according to claim 6, characterized in that: The step four, when blowing wind volume is lower than 20000Nm 3 / h, the PS converter air hole is punched and cleaned.

8. A method of protecting a PS converter for copper smelting according to claim 6, characterized in that: In step 1, the metallurgical crane is used to separate the hot material in liquid state from the cold material in solid state.

9. A method of protecting a PS converter for copper smelting as claimed in claim 6, characterized in that: In step 2, the cold material is crushed by a furnace mouth machine.

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