Method for obtaining crude copper by taking high-nickel copper concentrate as raw material and ensuring valuable metal recovery rate

Abstract

The invention discloses a method for obtaining crude copper by taking high nickel-copper concentrate as a raw material and ensuring the valuable metal recovery rate, which comprises the following steps: smelting the high nickel-copper concentrate in a side-blown converter, depleting smelting slag in an electric furnace, blowing in a Kaldo furnace, vulcanizing and blowing Kaldo slag in a PS converter, and recovering nickel by grinding and floating separation and acid dissolution and electrodeposition. According to the method, a new treatment process from the high-nickel-copper concentrate to the crude copper is achieved, the prepared crude copper can directly enter an anode furnace to be refined, then a qualified copper anode plate is obtained through disc casting, and meanwhile the recovery rate of copper and nickel in the high-nickel-copper concentrate is increased.

Description

Technical Field

[0001] The present invention belongs to the field of pyrometallurgy, and in particular relates to a method for obtaining blister copper by using high-nickel copper concentrate as a raw material while ensuring a recovery rate of valuable metals. Background Art

[0002] The direct entry of high-nickel copper concentrate into the copper smelting system may cause great disturbances to the copper smelting system, which is mainly manifested in two aspects: First, due to the large amount of nickel-containing concentrate entering the system, the nickel content of the copper system anode plate exceeds the standard, the qualified rate decreases, and the cost of electrolytic impurity removal increases significantly. Second, a large amount of nickel enters the slag during the smelting process of the copper system, the nickel loss increases, and the nickel yield cannot be guaranteed. In order to ensure the quality of copper system products, copper smelting companies generally use a large amount of standard copper concentrate (copper concentrate that does not contain nickel) to dilute the nickel content in the concentrate to the furnace entry standard (i.e. Ni≤0.5%), but this method cannot achieve effective nickel recovery. Summary of the Invention

[0003] (1) Technical problem to be solved: In view of the defect that the existing prior art copper smelting system causes significant disturbance to the copper smelting system when smelting high-nickel copper concentrate, the present invention provides a simple, low-cost method for obtaining crude copper using high-nickel copper concentrate as raw material while ensuring the recovery rate of valuable metals.

[0004] (2) The technical solution adopted by the present invention is as follows:

[0005] A method for obtaining blister copper using high-nickel copper concentrate as a raw material while ensuring a recovery rate of valuable metals comprises the following steps:

[0006] a: High-nickel copper concentrate side-blown furnace smelting: High-nickel copper concentrate, flux, and granular coal are mixed in a ratio of (100:20:1) and fed into a side-blown smelting furnace with an oxygen enrichment concentration of 80%, a flux rate of 20%, an oxygen-to-material ratio of 150, and a reducing agent rate of 1%. The smelting is carried out for 30 minutes to obtain matte with a Cu content of ≥75% and smelting slag. The high-nickel copper concentrate contains the following components: Cu 24.06%, Ni 3.76%, Fe 27.2%, S 28.76%, MgO 4.3%, and SiO2 5.71%. The white matte composition is: Cu 75.36%-77.89%, Ni 5.93%-6.17%, Fe 2.76%-2.97%, and S 16.67%-17.22%.

[0007] b: Electric furnace depleted smelting slag: Use an electric furnace to deplete the smelting slag. Mix the smelting slag, reducing agent, sulfiding agent and limestone in a ratio of 100:2:5:5. Place a small amount of mixed raw materials on the bottom of the electric furnace. Use coke to ignite the arc and send electricity. After the molten pool in the furnace is formed, gradually add the mixed materials into the furnace. Adjust the secondary current to ensure normal material chemistry. After the material chemistry is fully realized, enter the sedimentation and depletion stage. Adjust the secondary output current and voltage to ensure that there is no splashing at the furnace mouth. After 30 minutes of sedimentation and depletion, qualified high-nickel matte is produced. The produced depleted slag is sent to copper slag beneficiation for further recovery of Cu. The high-nickel matte contains Cu grade ≥45%, and the depleted slag contains Ni ≤0.3%.

[0008] c: Kaldo furnace blowing: The high nickel matte produced by the depletion process is combined with the white matte produced by the side-blown furnace to enter the Kaldo furnace. The high nickel matte, white matte, quartz and limestone are mixed in a ratio of 100:5:3 and blown in the Kaldo converter. The Kaldo converter is an intermittent operation. The main purpose of blowing is to remove nickel and form slag. After the slag is removed, high-grade blister copper and Kaldo slag are obtained. The blister copper contains Cu ≥ 97.5%, Ni ≤ 0.9%.

[0009] d: Sulphidicity blowing in PS converter of Kaldo slag: Sulphidicity blowing in PS converter is carried out by sulphidicity blowing of Kaldo slag. Sulphidicity blowing is carried out in PS converter of nickel system by mixing Kaldo slag and low nickel matte in a ratio of 1:1. Sulphidicity blowing is carried out by mixing low nickel matte (Ni 28%, Cu 16%, S23%) with low nickel matte (Ni 28%, Cu 16%, S23%) as sulphidicity blowing agent. The purpose of blowing is to sulphidize the oxides and remove part of Fe in the low nickel matte to obtain high nickel matte. The high nickel matte contains Ni ≥ 43% and Cu ≥ 25%.

[0010] e: High nickel matte is ground and flotated in the grinding and flotation system to obtain secondary copper concentrate (Cu≥65%, S20%) and secondary nickel concentrate (Ni≥62%, S22%). The secondary copper concentrate is returned to the side-blown furnace system for processing with high nickel copper concentrate. The secondary nickel concentrate enters the wet process system for pressure leaching, and the leachate is electrolytically deposited to obtain electrolytic nickel (Ni 99.96%).

[0011] 2. The method for obtaining blister copper using high-nickel copper concentrate as raw material and ensuring a recovery rate of valuable metals according to claim 1, wherein the reducing agent is granular coal.

[0012] A further technical solution is that in step b, the reducing agent is 2-3% and the added vulcanization rate is 3%-5%.

[0013] A further technical solution is that in step c, the crude copper produced by the Kaldo furnace is subjected to an oxidation-reduction process in an anode furnace and then cast to obtain a copper anode plate containing Cu≥99.1% and Ni≤0.5%.

[0014] (3) Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0015] The nickel and copper in the raw materials are extracted into white copper matte through pyrometallurgical oxygen-enriched smelting and depletion. Then, the nickel is removed into the slag through a series of blowing to obtain qualified blister copper. The blister copper can be refined into qualified copper anode plates. The slag is blown together with low-nickel matte in the nickel system PS converter to obtain high-nickel matte. The high-nickel matte is then subjected to grinding, flotation separation, leaching, and electrolytic deposition to recover nickel. This process is short and has high Ni and Cu recovery rates, with a Cu recovery rate of ≥98.6%, and especially a Ni recovery rate of over 93.5%.

[0016] The present invention strictly carries out side-blown furnace smelting of high-nickel copper concentrate, electric furnace depleted smelting slag, Kaldo furnace blowing, Kaldo slag PS converter sulfidation blowing, grinding and flotation of high-nickel matte in a grinding and flotation system to obtain secondary copper concentrate (Cu≥65%, S20%) and secondary nickel concentrate (Ni≥62%, S22%), the secondary copper concentrate is returned to the side-blown furnace system for processing with high-nickel copper concentrate, the secondary nickel concentrate enters a wet process system for pressure leaching, and the leachate is subjected to electrolytic deposition to obtain electronickel (Ni 99.96%). This process realizes a simple and low-cost method for obtaining crude copper using high-nickel copper concentrate as raw material and ensuring the recovery rate of valuable metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0019] like Figure 1 A method for obtaining crude copper using high nickel copper concentrate as raw material and ensuring the recovery rate of valuable metals, after step 1 of side-blown furnace smelting

[0020] Table 1 Composition of high nickel copper concentrate

[0021]

[0022] Table 2 Flux (quartz) composition

[0023]

[0024] Table 3 Composition of granular coal

[0025]

[0026] Table 4 Pyrite (sulfiding agent) composition

[0027]

[0028] Table 5 Limestone composition

[0029]

[0030] High-nickel copper concentrate, flux, and granular coal are mixed in a mass ratio of (100:20:1) and fed into a side-blown smelting furnace. The smelting temperature of the side-blown furnace is 1320°C, the oxygen enrichment concentration is 80%, the flux (quartz stone) rate is 20%, the oxygen-to-material ratio is 150, the reducing agent rate is 1%, and the sedimentation separation is 30 minutes. The smelting produces matte with a Cu grade of ≥75% and smelting slag. The high-nickel copper concentrate contains the following components: Cu 24.06%, Ni 3.76%, Fe 27.2%, S28.76%, MgO 4.3%, and SiO2 5.71%. The white matte composition is: Cu 75.36%-77.89%, Ni 5.93%-6.17%, Fe 2.76%-2.97%, and S16.67%-17.22%. The compositions of the obtained white matte and slag are as follows:

[0031] Table 6 Composition of white matte

[0032]

[0033] Table 7 Composition of smelting slag

[0034]

[0035]

[0036] Step 2: Smelting slag electric furnace depletion

[0037] Smelting slag, reducing agent (granular coal), sulfiding agent (pyrite), and limestone are evenly mixed in a ratio of 100:2:5:5. A small amount of the mixed materials is placed at the bottom of a 240kVA electric furnace. Coke is used to ignite the arc and power the furnace. Once a molten pool forms in the furnace, the mixed materials are gradually added. The secondary current is gradually adjusted based on the furnace reaction to ensure proper material chemistry. The furnace chemistry is monitored. Once the materials are fully chemistry, the settling and depletion stage begins. The secondary output current and voltage are adjusted based on the furnace chemistry to ensure no splashing from the furnace mouth. After 30 minutes of settling and depletion, qualified high-nickel matte (yield approximately 5%-8%) is produced. This is then combined with white matte from the side-blown furnace and fed into the Kaldo furnace. The resulting depleted slag is sent to copper slag beneficiation for further Cu recovery. The high-nickel matte contains ≥45% Cu, and the depleted slag contains ≤0.3% Ni.

[0038] Table 8 Composition of depleted matte

[0039]

[0040] Table 9 Depleted slag composition

[0041]

[0042] Step 3 Kaldor furnace refining

[0043] The high-nickel matte produced by depletion is combined with the white matte produced by the side-blown furnace and enters the Kaldo furnace together. The high-nickel matte, white matte, quartz and limestone are mixed in the ratio of 100:5:3 and blown in the Kaldo converter. The Kaldo converter is an intermittent operation for blowing. The main purpose of blowing is to remove nickel and form slag. After the slag is removed, higher-grade blister copper and Kaldo slag are obtained. The blister copper contains Cu ≥ 97.5% and Ni ≤ 0.9%.

[0044] Table 10 Composition of crude copper

[0045]

[0046] Table 11 Composition of Kaldor slag

[0047]

[0048] Step 4 Anode furnace refining

[0049] The crude copper contains Ni≤0.9%, which meets the technical requirements of the anode furnace refining. This step is a conventional anode furnace refining process operation (oxidation and reduction process), and this patent will not repeat it.

[0050] Step 5: Sulphurization and blowing of Kaldo slag in PS converter

[0051] Kaldo slag PS converter sulfidation blowing: Kaldo slag is sulfided and blown in a PS converter. Kaldo slag and low-nickel matte are mixed in a 1:1 ratio in a nickel-based PS converter. The sulfiding agent is low-nickel matte (Ni 28%, Cu 16%, S 23%). The purpose of the blowing process is to sulfidize the oxides and remove some of the Fe in the low-nickel matte, producing a high-nickel matte containing ≥43% Ni and ≥25% Cu. (Note: The change in the Ni / Cu ratio here is due to the use of low-nickel matte from the nickel PS converter as the sulfiding agent.)

[0052] Table 12 High nickel matte composition

[0053]

[0054] Step 6: High matte grinding and flotation and grinding and flotation concentrate treatment

[0055] The high-nickel matte is ground and flotated in the grinding and flotation system to obtain secondary copper concentrate (Cu≥65%, S20%) and secondary nickel concentrate (Ni≥62%, S22%). The secondary copper concentrate is returned to the side-blown furnace system for processing with the high-nickel copper concentrate. The secondary nickel concentrate enters the wet process system for pressure leaching, and the leachate is electrolytically deposited to obtain electrolytic nickel (Ni 99.96%).

[0056] Table 13 Composition of secondary nickel concentrate

[0057]

[0058] Table 14 Composition of secondary copper concentrate

[0059]

[0060] Table 15 Electron Nickel Composition

[0061]

[0062] This method has three characteristics: First, it utilizes the oxidation of complex sulfides under high oxygen potential, and a large amount of FeO and quartz stone combine to form fayalite to form slag. Valuable metals such as Ni and Cu enter the copper matte to obtain white matte, and the white matte is blown into the Kaldo furnace to remove Ni metal to obtain qualified crude copper. Second, it is a slag depletion process, in which reducing agents and fluxes are used to destroy the fayalite structure, and the valuable metals contained in the slag are reduced and sulfided to improve the recovery rate of valuable metals. Third, the Kaldo slag is deeply sulfided and blown in a PS converter to obtain high-nickel matte, which is separated by grinding and flotation, and then pressurized leaching and electrolytic recovery of nickel. Based on the above characteristics, this method designs an oxidation slagging-reduction sulfidation depletion-enhanced sulfidation process-leaching electrolysis to complete the processing process of high-nickel copper concentrate.

[0063] The above are only preferred embodiments of the present invention.

Claims

1. A method for obtaining crude copper using high-nickel copper concentrate as raw material and ensuring the recovery rate of valuable metals, characterized in that: The following steps are involved: a: Side-blown furnace smelting of high-nickel copper concentrate: high-nickel copper concentrate, flux and granular coal are mixed in proportion (100:20:1) and fed into the side-blown smelting furnace, with oxygen enrichment concentration of 80%, flux rate of 20%, oxygen-to-material ratio of 150, reducing agent rate of 1%, sedimentation separation for 30 minutes, and smelting to obtain matte with Cu grade ≥75% and smelting slag; high-nickel copper concentrate contains: Cu 24.06%, Ni 3.76%, Fe 27.2%, S 28.76%, MgO 4.3%, SiO2 5.71%; white matte composition: Cu 75.36%-77.89%, Ni 5.93%-6.17%, Fe2.76%-2.97%, S 16.67%-17.22%, b: Electric furnace depleted smelting slag: Use an electric furnace to deplete the smelting slag. Mix the smelting slag, reducing agent, sulfiding agent and limestone in a ratio of 100:2:5:

5. Spread some of the mixed raw materials on the bottom of the electric furnace. Use coke to start the arc and send electricity. After the molten pool in the furnace is formed, gradually add the mixed materials into the furnace. After the materials are completely fused, enter the sedimentation and depletion stage. After 30 minutes of sedimentation and depletion, qualified high-nickel matte is produced. The depleted slag is sent to copper slag beneficiation for further recovery of Cu. The high-nickel matte contains Cu grade ≥45%, and the depleted slag contains Ni ≤0.3%. c: Kaldo furnace blowing: The high-nickel matte produced by the depletion furnace is combined with the white matte produced by the side-blown furnace to enter the Kaldo furnace. The high-nickel matte, white matte, quartz and limestone are mixed in a ratio of 100:5:3 and blown in the Kaldo converter. The Kaldo converter is an intermittent operation blowing furnace. The main purpose of blowing is to remove nickel and make slag. After the slag is removed, blister copper and Kaldo slag are obtained. The blister copper contains Cu≥97.5% and Ni≤0.9%. d: Sulphiding and blowing of Kaldor slag in PS converter: Sulphiding and blowing of Kaldor slag in PS converter. Sulphiding and blowing of Kaldor slag and low nickel matte are carried out in PS converter of nickel system in a ratio of 1:

1. The sulphiding agent is low nickel matte (Ni 28%, Cu 16%, S 23%). The purpose of blowing is to sulphidize the oxides and remove part of Fe in the low nickel matte to obtain high nickel matte. The high nickel matte contains Ni ≥ 43% and Cu ≥ 25%. e: High nickel matte is ground and flotated in the grinding and flotation system to obtain secondary copper concentrate (Cu≥65%, S 20%) and secondary nickel concentrate (Ni≥62%, S 22%). The secondary copper concentrate is returned to the side-blown furnace system for treatment with high nickel copper concentrate. The secondary nickel concentrate enters the wet system for pressure leaching, and the leachate is electrolytically deposited to obtain electrolytic nickel (Ni 99.96%).

2. The method of claim 1 for obtaining crude copper using high-nickel copper concentrate as raw material and ensuring the recovery rate of valuable metals, characterized in that: The reducing agent is granular coal.

3. The method of claim 1 for obtaining crude copper using high-nickel copper concentrate as raw material and ensuring the recovery rate of valuable metals, characterized in that: In step b, the reducing agent is 2-3% of the mass of the smelting slag, and the added sulfurization rate is 3%-5% of the mass of the smelting slag.

4. The method of claim 1 for obtaining crude copper using high-nickel copper concentrate as raw material and ensuring the recovery rate of valuable metals, characterized in that: In step c, the crude copper produced by the Kaldo furnace is subjected to an oxidation-reduction process in an anode furnace and then cast to obtain a copper anode plate containing Cu≥99.1% and Ni≤0.5%.

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