A method for preparing iron and silicate slag from copper slag

Abstract

The present invention provides a method for preparing iron and silicate slag from copper slag, and belongs to the technical field of solid waste resource utilization. The method for preparing iron and silicate slag from copper slag provided by the present invention comprises: electrolyzing molten copper slag to obtain iron and silicate slag; the temperature of the molten copper slag is 1200-1400°C. The present invention performs high-temperature electrolysis in a molten state of the copper slag, and can fully reduce the iron oxide in the copper slag to iron, thereby improving the recovery rate of iron. Experimental results show that the iron recovery rate of the method provided by the present invention is 80.51-95.52%.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste resource utilization, and specifically relates to a method for preparing iron and silicate slag from copper slag. Background Art

[0002] Copper slag is the secondary tailings discarded after copper smelting and beneficiation. At present, the method for treating copper slag mainly uses copper slag as raw material, adds a modifier containing alkali metal oxides to the molten copper slag or controls the atmosphere by blowing gas at the same time to obtain iron ore concentrate and tailings. The recovery rate of iron in the iron ore concentrate prepared by this method is low. Therefore, how to improve the method to increase the recovery rate of iron has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0003] The object of the present invention is to provide a method for preparing iron and silicate slag from copper slag. The method provided by the present invention can improve the recovery rate of iron.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a method for preparing iron and silicate slag from copper slag, comprising:

[0006] The molten copper slag is electrolyzed to obtain iron and silicate slag; the temperature of the molten copper slag is 1200-1400°C.

[0007] Preferably, the total iron content in the molten copper slag is 20-46wt%.

[0008] Preferably, the temperature of the molten copper slag is 1300-1400°C.

[0009] Preferably, the electrolysis voltage is 0.4-10V, the electrolysis current is 0.1-10A, and the electrolysis time is 0.5-3h.

[0010] Preferably, the electrolysis voltage is 1-6V, the electrolysis current is 1-9A, and the electrolysis time is 2h.

[0011] Preferably, the voltage of the electrolysis is 4.8~5.8V.

[0012] Preferably, the material of the cathode and the material of the anode used in the electrolysis independently include at least one of graphite, platinum, rhodium, iridium, silicon carbide and molybdenum silicide.

[0013] Preferably, the material of the cathode and the material of the anode used in the electrolysis are graphite.

[0014] Preferably, the silicate slag is used to prepare silicate building materials by a fusion casting method.

[0015] Preferably, the iron is recovered for use in steel production.

[0016] The present invention provides a method for preparing iron and silicate slag from copper slag, comprising: electrolyzing molten copper slag to obtain iron and silicate slag; the temperature of the molten copper slag is 1200-1400°C. The present invention performs high-temperature electrolysis in a molten state of the copper slag, and can fully reduce the iron oxide in the copper slag to iron, thereby improving the recovery rate of iron. Experimental results show that the iron recovery rate of the method provided by the present invention is 80.51-95.52%. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the XRD pattern of iron prepared in Example 1;

[0018] Figure 2 This is the XRD pattern of iron prepared in Example 2. DETAILED DESCRIPTION

[0019] The present invention provides a method for preparing iron and silicate slag from copper slag, comprising:

[0020] The molten copper slag is electrolyzed to obtain iron and silicate slag; the temperature of the molten copper slag is 1200-1400°C.

[0021] The present invention has no particular limitation on the sources of the raw materials, and commercially available products known to those skilled in the art may be used.

[0022] In the present invention, the molten copper slag is preferably the copper slag just discharged from a copper smelting plant.

[0023] In the present invention, the total iron content in the molten copper slag is preferably 20-46wt%. As an embodiment, the total iron content in the molten copper slag can be 25wt%, 30wt%, 35wt%, 43.55wt% or 45wt%.

[0024] In the present invention, the temperature of the molten copper slag is 1200-1400° C., preferably 1300-1350° C. The present invention fully utilizes the heat energy of the molten copper slag for electrolysis, thereby recovering the iron element in the copper slag.

[0025] In the present invention, the voltage of the electrolysis is preferably 0.4-10V, more preferably 1-6V, and more preferably 4.8-5.8V; the current of the electrolysis is preferably 0.1-10A, more preferably 1-9A; the time of the electrolysis is preferably 0.5-3h, more preferably 2h. The present invention limits the process parameters of the electrolysis within the above range to improve the degree of electrolysis, thereby improving the recovery rate of iron.

[0026] As an embodiment, the voltage of the electrolysis may be 4.9V, 5.0V, 5.1V, 5.2V, 5.3V, 5.4V, 5.5V, 5.6V or 5.7V; the current of the electrolysis may be 2A, 3A, 4A, 5A, 6A, 7A or 8A.

[0027] In the present invention, the cathode material and the anode material used in the electrolysis independently preferably include at least one of graphite, platinum, rhodium, iridium, silicon carbide and molybdenum silicide. As an embodiment, the cathode material and the anode material used in the electrolysis can be graphite.

[0028] In the present invention, the electrolysis is preferably carried out in a high temperature reactor; the material of the high temperature reactor is preferably a refractory material. The present invention has no particular limitation on the type of the refractory material, and any refractory material well known to those skilled in the art can be used.

[0029] In the present invention, the silicate slag is preferably used to prepare silicate building materials by a melting and casting method; the silicate building materials are preferably bricks or dense aggregates. The present invention has no special restrictions on the operation of preparing silicate building materials by the melting and casting method, and the operation well known to those skilled in the art can be used.

[0030] In the present invention, the iron is preferably recycled for steel production. The present invention reduces more than 80 wt% of the iron oxides in the molten copper slag to iron, which settles in the lower layer, and the silicate slag is in the upper layer.

[0031] The present invention directly recovers iron from copper slag by electrolyzing molten copper slag, and the obtained silicate slag can be used to prepare silicate building materials to replace fired products. The method efficiently utilizes the iron and silicate components in the molten copper slag, realizes the coordinated utilization of molten copper slag material and thermal energy, improves the resource utilization efficiency of molten copper slag, and reduces carbon emissions in the high-energy-consuming copper metallurgical industry.

[0032] The method provided by the present invention does not require the additional addition of reducing agents and modifiers. Starting from molten copper slag, the components of the molten copper slag are adjusted by electrolysis in an external electric field to obtain silicate building materials and iron, thereby realizing the three-way utilization of the "heat, iron, and slag" resources of the molten copper slag, which is conducive to achieving carbon emission reduction in the high-energy consumption copper metallurgical industry.

[0033] The iron obtained by the present invention can be directly used for recycling in the steel industry; the silicate slag obtained can be used to prepare silicate building materials, bricks or dense aggregates through a melting and casting method. The synergistic utilization of molten copper slag and thermal energy is achieved, and the resource utilization efficiency of molten copper slag is improved. On the one hand, metallurgical waste slag is effectively utilized, the stacking cost is reduced, and the occupation of land resources and environmental pollution caused by metallurgical slag stacking are avoided; on the other hand, CO 2It will help reduce carbon emissions in the high-energy-consuming copper metallurgical industry.

[0034] The present invention performs high-temperature electrolysis in a molten state of copper slag, and can fully reduce the iron oxides in the copper slag to iron, thereby improving the recovery rate of iron.

[0035] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The copper slag used in the embodiments is obtained from a copper smelting enterprise.

[0037] Example 1

[0038] The method for preparing iron and silicate slag from copper slag is:

[0039] The molten copper slag at 1400°C is transferred to a high-temperature reactor made of refractory materials, and a graphite anode and a graphite cathode are inserted into the molten copper slag. Then, a current of 9A is passed at a voltage of 4.9V for electrolysis for 2h to obtain an upper silicate slag and a lower iron layer. The total iron content in the molten copper slag is 43.55wt%. The upper silicate slag is used to prepare silicate building materials through a melting and casting method. The iron is recovered for steel production.

[0040] Example 2

[0041] The method for preparing iron and silicate slag from copper slag is:

[0042] The molten copper slag at 1300°C is transferred to a high-temperature reactor made of refractory materials, and a graphite anode and a graphite cathode are inserted into the molten copper slag. Then, a current of 9A is passed at a voltage of 5.8V for electrolysis for 2h to obtain an upper silicate slag and a lower iron layer. The total iron content in the molten copper slag is 43.55wt%. The upper silicate slag is used to prepare silicate building materials through a melt-casting method. The iron is recovered for steel production.

[0043] Example 3

[0044] The method for preparing iron and silicate slag from copper slag is:

[0045] The 1350°C molten copper slag is transferred to a high-temperature reactor made of refractory materials, and a graphite anode and a graphite cathode are inserted into the molten copper slag. Then, a current of 9A is passed at a voltage of 4.8V for electrolysis for 2h to obtain an upper silicate slag and a lower iron layer. The total iron content in the molten copper slag is 43.55wt%. The upper silicate slag is used to prepare silicate building materials through a melt-casting method. The iron is recovered for steel production.

[0046] The iron recovery rate of the molten copper slag in Examples 1 to 3 was tested, and the results are shown in Table 1; wherein the iron recovery rate R Fe From formula I we get:

[0047] R Fe = Formula I;

[0048] In the formula, C 0 is the total iron content in the molten copper slag, C 1 It is the total iron content in silicate slag.

[0049] Table 1 Iron recovery rate of molten copper slag in Examples 1 to 3

[0050]

[0051] It can be seen from Table 1 that the iron recovery rate in each embodiment is relatively high, and most of the iron in the molten copper slag is basically recovered.

[0052] The lower iron layer obtained in Example 1-2 was subjected to XRD test, and the results were as follows: Figure 1~2 As shown, Figure 1 This is the XRD pattern of iron prepared in Example 1; Figure 2 This is the XRD pattern of iron prepared in Example 2.

[0053] from Figure 1 and 2 It can be seen that the main phase is iron, and there are no other impurity peaks, and the composition is relatively pure.

[0054] The silicate slag prepared in Examples 1 to 3 was subjected to XRF testing. The results are shown in Table 2, in units of wt%.

[0055] Table 2 XRF results of silicate slag prepared in Examples 1 to 3

[0056]

[0057] It can be seen from Table 2 that the Fe content of the silicate slag prepared in Examples 1 to 3 is 2 O 3The content is relatively small, the iron reduction effect is better, and the main composition is silicon dioxide and calcium oxide. Silicate building material bricks or dense aggregates can be prepared by the melt casting method.

[0058] Comparative Example 1

[0059] On the basis of Example 1, only a graphite anode and a graphite cathode are inserted, and no electric field is applied to both ends of the electrodes, and other conditions remain unchanged, thereby obtaining an upper layer of silicate slag and a lower layer of iron.

[0060] The silicate slag prepared in Example 1 and Comparative Example 1 was subjected to XRF testing. The results are shown in Table 3, in units of wt%.

[0061] Table 3 XRF results of silicate slag prepared in Example 1 and Comparative Example 1

[0062]

[0063] It can be seen from Table 3 that the Fe content in the copper slag after the electric field is applied in Example 1 is 2 O 3 The Fe 2 O 3 , indicating that graphite has an influence on Fe 2 O 3 The reduction effect is limited, and by electrolysis, Fe 2 O 3 is effectively reduced, and the components of silicate slag are mainly SiO 2 , CaO and Al 2 O 3 etc., Fe 2 O 3 The content is low.

[0064] In summary, the method provided by the present invention fully utilizes the heat energy of molten copper slag by electrolyzing molten copper slag, recovers iron elements, and enables silicate slag to be used to prepare silicate building materials, thus realizing the coordinated utilization of bulk solid waste heat energy and materials. On the one hand, it effectively utilizes metallurgical waste slag, reduces the stacking cost, and avoids the occupation of land resources and environmental pollution caused by metallurgical slag stacking; on the other hand, it reduces CO 2 It will help reduce carbon emissions in the high-energy-consuming copper metallurgical industry.

[0065] It can be seen from the above examples that the method provided by the present invention can improve the recovery rate of iron.

[0066] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing iron and silicate slag from copper slag, characterized in that: for: The molten copper slag is electrolyzed to obtain iron and silicate slag; the temperature of the molten copper slag is 1200-1400°C; the molten copper slag is the copper slag just out of the copper smelting plant; the silicate slag is used to prepare silicate building materials by a melting and casting method; The voltage of the electrolysis is 4.8~5.8V.

2. The method according to claim 1, characterized in that The total iron content in the molten copper slag is 20-46wt%.

3. The method according to claim 1, characterized in that The temperature of the molten copper slag is 1300-1400°C.

4. The method according to claim 1, characterized in that: The electrolysis current is 0.1-10A, and the electrolysis time is 0.5-3h.

5. The method according to claim 1 or 4, characterized in that: The electrolysis current is 1-9A, and the electrolysis time is 2h.

6. The method according to claim 1, characterized in that The material of the cathode and the material of the anode used in the electrolysis independently include at least one of graphite, platinum, rhodium, iridium, silicon carbide and molybdenum silicide.

7. The method according to claim 1 or 6, characterized in that: The cathode and anode materials used in the electrolysis are graphite.

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