Processing methods for low-nickel, high-copper concentrates rich in platinum group metals

Abstract

This invention belongs to the field of metal production or refining technology, and discloses a method for processing low-nickel, high-copper concentrate rich in platinum group metals. The method includes: batching copper-nickel concentrate and sending it to a smelting furnace for smelting, controlling a low grade of copper-nickel matte, and producing copper-nickel matte and smelting slag; sending the copper-nickel matte to a first blowing furnace for continuous blowing, controlling a shallow continuous blowing depth, and producing raw blister copper and first blowing slag; sending the raw blister copper to a bottom-blown refining furnace for pyrometallurgical refining, producing anode copper, and casting the anode copper into anode plates and sending them to the electrolysis process. This invention has the advantages of high efficiency and short process, reduces the nickel content in the anode copper, and is conducive to improving the nickel recovery rate in the subsequent first blowing slag.

Description

Technical Field

[0001] This invention relates to the field of metal production or refining technology, and in particular to a method for processing low-nickel, high-copper concentrates rich in platinum group metals. Background Technology

[0002] Copper is a vital material for national economic development, and its importance is becoming increasingly prominent with the accelerating pace of industrialization. Currently, copper smelting can be divided into pyrometallurgical smelting and hydrometallurgical smelting. Pyrometallurgical copper smelting accounts for 85% of global copper production, and the smelting process is further divided into flash smelting and molten pool smelting. With the rapid development of flash smelting and various oxygen-enriched molten pool smelting technologies, the replacement of PS converter blowing technology by continuous blowing technology is inevitable.

[0003] The copper pyrometallurgical process generally includes processes such as smelting, blowing, pyrometallurgical refining, and electrolytic refining.

[0004] The inventors recognized that for low-nickel, high-copper concentrates rich in platinum group metals (PGMs), if the traditional copper concentrate pyrometallurgical process is used, the recovery rate of the abundant metallic nickel and platinum group metals (PGMs) is low. At the same time, when the nickel content of the anode copper after pyrometallurgical refining is high, it also has an adverse effect on the subsequent electrolytic refining.

[0005] There are currently few reports on efficient processing techniques for low-nickel, high-copper concentrates rich in platinum group metals (PGMs).

[0006] Jinchuan Group Co., Ltd.'s Chinese patent application CN 102888520A discloses a method for efficiently extracting nickel, cobalt, copper, and platinum group metals from complex nickel-copper concentrate. The method first produces high-nickel matte through a traditional nickel smelting process (ore dressing-smelting-converter blowing). Then, the high-nickel matte undergoes slow cooling and grinding / flotation separation to obtain three products: secondary nickel concentrate with a Ni content greater than 60%, secondary copper concentrate with a Cu content greater than 65%, and a primary copper-nickel alloy with a Ni content of 60-65%, a Cu content of 15-25%, and a small amount of precious metals. These three products then require further processing using the following different techniques: Secondary nickel concentrate processing: The obtained secondary nickel concentrate is sent to a reverberatory furnace for smelting to obtain nickel anode plates with crude nickel as the main component. Then, the nickel anode plates are sent to an electrolysis process for electrolysis to obtain nickel cathode plates. After the electrolysis process, the remaining nickel anode plates are sent to a grinding and flotation system for grinding. The grinding product is pulped and then leached using a conventional leaching process. After the electrolysis process, the cobalt-containing electrolyte is filtered to obtain cobalt-containing solid slag. The solid slag is extracted to obtain cobalt hydroxide. The raffinate after extraction is injected with resin ion exchange to recover cobalt ions.

[0007] Primary copper-nickel alloy processing: The obtained primary copper-nickel alloy is smelted in an alloy sulfidation furnace to obtain a secondary high-nickel alloy; the secondary high-nickel matte is separated by a grinding and flotation system to obtain a secondary copper-nickel alloy with a Ni content of 59-69%, a Cu content of 13-19%, and a small amount of precious metals; the secondary copper-nickel alloy is processed by a two-stage controlled electrochlorination and a one-stage alkaline leaching desulfurization and desiliconization process, and then pressure leaching is used to remove base metals to obtain a precious metal concentrate containing more than 10% Pt.

[0008] Secondary copper concentrate processing: The obtained secondary copper concentrate is smelted in an autothermal furnace, blown in a Kaldor furnace, and refined in an anode furnace to obtain copper anode plates, which are then sent to the copper electrolysis process for electrolysis to obtain copper cathode plates.

[0009] Although this process solves the smelting problem of complex and difficult-to-process nickel-copper ore, improves the recovery rate of nickel, cobalt and platinum group metals, and increases the processing capacity of nickel-copper raw materials, the inventors have noticed that this method has disadvantages such as a long process flow, the use of many metallurgical furnaces and kilns, and large investment. Summary of the Invention

[0010] According to one embodiment of the present invention, the objective is to provide a method for processing low-nickel, high-copper concentrate rich in platinum group metals (PGMs) to solve the problems existing in the current copper smelting process for processing low-nickel, high-copper concentrate rich in PGMs.

[0011] The above objective can be achieved through the following technical solutions: According to one aspect of the present invention, a method for processing platinum group metal-rich, low-nickel, high-copper concentrate is provided, comprising: The copper-nickel concentrate is batched and sent to a smelting furnace for smelting. The grade of copper-nickel matte is controlled to produce copper-nickel matte and smelting slag. The total copper and nickel content in the copper-nickel matte is 60-70%. The copper-nickel matte is fed into the first smelting furnace for continuous smelting. The depth of continuous smelting is controlled to produce raw blister copper and first smelting slag. The raw blister copper contains 1-3% nickel and 85-95% copper. The raw copper is sent to a bottom-blown refining furnace for pyrometallurgical refining to produce anode copper, which is then cast into anode plates and sent to the electrolysis process.

[0012] Preferably, the method further includes: sending the first smelting slag to a depletion electric furnace for slag depletion to obtain low-nickel sulfur and depletion slag; sending the low-nickel sulfur to a second smelting furnace for nickel matte smelting to obtain high-nickel matte and second smelting slag; returning the second smelting slag to the depletion electric furnace; and using the high-nickel matte for external sale, wet processing, or mineral processing.

[0013] Preferably, the temperature of the continuous blowing process is 1300–1400°C.

[0014] Preferably, the first blowing slag contains 5-9% nickel and 10-20% copper.

[0015] Preferably, the method further includes: slowly cooling and crushing the smelting slag, sending it to a slag beneficiation system to recover copper, nickel and platinum group metals, obtaining a first slag tailings and a first slag concentrate containing platinum group metals, and returning the first slag concentrate to the smelting furnace for smelting; Preferably, the method further includes: slowly cooling and crushing the depleted slag, sending it to a slag beneficiation system to recover platinum group metals, obtaining a second slag tailings and a second slag concentrate containing platinum group metals, and returning the second slag concentrate to a smelting furnace for smelting.

[0016] Preferably, the depletion furnace includes a furnace body, which is divided into a front depletion zone and a rear settling zone, and a side-blowing spray gun is provided on the side wall of the furnace body in the depletion zone.

[0017] Preferably, during the slag depletion process, additives and / or fuel are injected using a side-blowing spray gun.

[0018] Preferably, the second blowing furnace is a bottom-blown furnace.

[0019] Preferably, in the step of batching copper-nickel concentrate and sending it to a smelting furnace for smelting, the copper concentrate is batched and sent to an oxygen-enriched side-blown smelting furnace for oxygen-enriched side-blown smelting, or the copper concentrate is batched and sent to a bottom-blown smelting furnace for oxygen bottom-blown smelting, or the copper concentrate is batched and sent to a flash smelting furnace for flash smelting.

[0020] Preferably, in the step of sending the copper-nickel matte to the first smelting furnace for continuous smelting, the copper-nickel matte is sent to a multi-lance top-blown furnace, a bottom-blown furnace, or a flash smelting furnace for continuous smelting.

[0021] Preferably, during the pyrometallurgical refining process, refining slag is also produced.

[0022] Preferably, the method further includes: returning the refining slag to the smelting or continuous blowing step.

[0023] Preferably, the nickel content in the anode copper is no higher than 0.5%; Preferably, the copper-nickel matte, raw blister copper, first smelting slag, and low-nickel sulfur are all conveyed hot using a trough; the second smelting slag is returned to the depletion furnace hot via a bun or returned to the depletion furnace in a cooled, solid state.

[0024] Beneficial effects: The present invention provides a method for processing platinum group metal-rich low-nickel high-copper concentrate. By batching the platinum group metal-rich low-nickel high-copper concentrate (or return slag concentrate) and sending it to a smelting furnace for smelting, and controlling the low copper-nickel matte grade, nickel is allowed to enter the copper matte phase as much as possible, thereby improving the recovery rate of nickel from the subsequent blowing slag. The hot copper-nickel matte produced by the smelting furnace can be sent to the first blowing furnace for continuous blowing through a trough, and the blowing depth is controlled to facilitate the subsequent low-cost and high-yield recovery of nickel. The raw blister copper produced by continuous blowing can flow into the bottom-blown refining furnace through a trough. The raw blister copper is directly refined by fire using the improved bottom-blown refining furnace, further reducing the nickel content in the anode copper, thereby solving the problem that the high nickel content of the anode copper has an adverse effect on electrolytic refining.

[0025] Based on the control of copper-nickel matte grade during smelting and the control of shallow blowing depth during continuous blowing, nickel enters the first blowing slag. This first blowing slag is then added to a depletion furnace for slag depletion, producing low-nickel matte which is transported to a second blowing furnace for nickel matte blowing to obtain high-nickel matte. This achieves high nickel metal recovery and reduces nickel recovery costs. The obtained high-nickel matte can be air-crushed and sold externally or sent for wet leaching to produce industrial-grade nickel sulfate. Alternatively, the high-nickel matte can be slowly cooled and sent to ore beneficiation to produce secondary nickel concentrate or secondary copper concentrate. The second blowing slag obtained from nickel matte blowing can be returned to the depletion furnace in hot form via a bale (i.e., slag bale), or returned to the depletion furnace in solid form after cooling.

[0026] By slowly cooling and crushing the lean slag produced by the lean slag furnace before sending it to a slag beneficiation system (recovering PGM), the slag concentrate is returned to the smelting furnace, achieving the enrichment and recovery of platinum group metals (PGMs). The resulting tailings can be sold externally. Similarly, by slowly cooling and crushing the smelting slag before sending it to a slag beneficiation system, the slag concentrate is returned to the smelting furnace, achieving the enrichment and recovery of copper, nickel, and PGMs. The resulting tailings can also be sold externally.

[0027] Compared with the prior art, some embodiments of the present invention have the following advantages: 1) During the smelting process using a smelting furnace, the copper-nickel matte grade (Ni+Cu) is controlled below 70%, and the smelting oxygen potential is controlled to allow Ni to enter the copper matte phase as much as possible. This ensures the copper recovery rate and also helps to improve the nickel recovery rate during the subsequent smelting of the first blowing slag.

[0028] 2) During the continuous blowing process in the blowing furnace, a shallow blowing depth is controlled to ensure that the copper grade of the crude copper does not exceed 95% and the nickel content is 1-3%. Controlling the blowing at a shallow depth can achieve continuous blowing of nickel-containing copper matte while avoiding the risks of foamy slag from deep blowing. Compared with deep blowing, the shallow blowing of crude copper in this invention results in a lower Cu / Ni ratio in the blowing slag, a higher direct copper recovery rate, and reduces the system investment and operating costs for recovering nickel from the blowing slag.

[0029] 3) The raw copper with a nickel content of 1-3% produced by continuous blowing is directly sent to pyrometallurgical refining, where an improved bottom-blown refining furnace is used for pyrometallurgical refining. The pyrometallurgical refining process undertakes part of the nickel removal task. Compared with traditional rotary anode furnace refining, the bottom-blown refining furnace has a higher air supply intensity and a more efficient impurity removal capacity.

[0030] 4) The present invention adopts a shallow blowing furnace + bottom blowing refining furnace refining process after smelting. Unlike the two-stage blowing process (shallow blowing + deep blowing), the present invention integrates deep blowing and anode furnace refining into bottom blowing refining furnace refining, which requires fewer furnaces and realizes the connection of the process melt flow channels. In the two-stage blowing process, the second stage deep blowing in the converter is carried out in a Kaldor furnace, which requires the melt to be transported in a bag and cannot be connected by flow channels. When the processing volume is large, the melt hoisting volume is very large.

[0031] 5) In the processes of smelting, continuous blowing, pyrometallurgical refining and slag depletion, hot continuous operation can be achieved through troughs, which reduces the process of hoisting the slag, reduces the labor intensity of workers, and allows for a relatively large annual processing capacity of copper concentrate.

[0032] 6) Control the blowing temperature so that the slag can be discharged in liquid form, and there is less adhesion in the furnace.

[0033] 7) PGM beneficiation was carried out on the smelting slag and the depleted slag produced by smelting, which improved the recovery rate of PGM.

[0034] 8) The process flow is relatively short, the metallurgical furnaces involved are relatively mature, and they are common in the copper and nickel smelting industry. The process operation is relatively simple. The number of metallurgical furnaces involved is relatively small, and the metallurgical furnaces can be arranged in one plant. The investment is small and the operating cost is low. Attached Figure Description

[0035] Figure 1 This is a process flow diagram of a method for processing low-nickel, high-copper concentrate rich in platinum group metals according to an embodiment of the present invention. Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below with reference to embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0037] Traditional copper smelting processes for low-nickel, high-copper concentrates rich in platinum group metals (PGMs) suffer from drawbacks. Because the nickel and PGM content in copper concentrates is higher than in conventional copper concentrates, the recovery rates of these abundant nickel and PGMs are low. Furthermore, the high nickel content in the anode copper after pyrometallurgical refining negatively impacts subsequent electrolytic refining. As described earlier, Chinese patent application CN102888520A discloses a method for efficiently extracting nickel, cobalt, copper, and PGMs from complex nickel-copper concentrates. However, this method suffers from drawbacks such as a long process flow (including processes like reverberatory furnace electrolysis, cobalt ion recovery via resin ion exchange column, alloy sulfidation furnace blowing, controlled electrochlorination, and alkaline leaching desulfurization), the use of numerous metallurgical furnaces, and high investment costs.

[0038] To address the shortcomings of existing traditional copper smelting processes in processing low-nickel, high-copper concentrates rich in platinum group metals (PGMs), this invention provides a novel process for processing such concentrates. This process employs a highly efficient, short-flow refining process using a smelting-continuous blowing-bottom blowing furnace. By controlling the copper-nickel matte grade and the shallower continuous blowing depth, the nickel content in the anode copper can be reduced, solving the problem of high nickel content affecting electrolytic refining. Furthermore, nickel and PGMs can be recovered with high efficiency. Compared to traditional copper smelting processes, this method offers advantages such as higher metal recovery rates, better economic benefits, and the ability to achieve comprehensive multi-metal recovery from the concentrate.

[0039] In some embodiments of the present invention, a method for processing platinum group metal-rich, low-nickel, high-copper concentrate is provided, comprising: 1) Copper concentrate is batched and sent to a smelting furnace for smelting, controlling a relatively low copper-nickel matte grade to produce copper-nickel matte and smelting slag. Further, the copper-nickel matte grade (Cu+Ni) is 60-70%, for example, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, etc.

[0040] 2) The copper-nickel matte is fed into the first smelting furnace for continuous smelting, with a shallow continuous smelting depth controlled to produce first smelting slag and raw blister copper. Further, the raw blister copper contains 1-3% nickel and 85-95% copper; the first smelting slag contains 5-9% Ni and 10-20% Cu. To ensure the slag is discharged in a liquid state and to minimize furnace adhesion, the continuous smelting temperature is controlled at 1300-1400℃, for example, 1300℃, 1320℃, 1350℃, 1380℃, 1400℃, etc.

[0041] 3) The raw copper is sent to a bottom-blown refining furnace for pyrometallurgical refining to produce anode copper. The anode copper is then cast into anode plates and sent to the electrolysis process. The refining slag produced by pyrometallurgical refining can be cooled, crushed, and returned to the smelting or blowing process to recover metals such as nickel and copper.

[0042] The copper pyrometallurgical process adopts a process of copper-nickel concentrate batching and smelting, continuous copper-nickel matte blowing, bottom blowing refining of raw copper in a pyrometallurgical furnace, and anode copper casting. This process controls the copper-nickel matte grade to a lower level and the continuous blowing depth to a shallower level, thereby reducing the nickel content in the anode copper and facilitating subsequent nickel recovery.

[0043] During the smelting process, a relatively low copper-nickel matte grade is controlled to ensure the subsequent copper yield while maximizing nickel inclusion in the copper matte phase. Traditional oxygen-enriched smelting produces copper-nickel matte with a grade of 72%-75%, while this process controls the smelted copper-nickel matte grade (Ni+Cu) below 70%. The relatively low oxygen potential allows more nickel from the copper concentrate to enter the copper matte phase, while the lower Ni content in the smelting slag improves the Ni recovery rate in subsequent smelting.

[0044] The pyrometallurgical smelting process employs either an oxygen-enriched side-blown smelting scheme, an oxygen-enriched bottom-blown smelting scheme, or a flash smelting scheme, with corresponding equipment including an oxygen-enriched side-blown smelting furnace, a bottom-blown smelting furnace, or a flash smelting furnace. Given the high nickel content in copper-nickel concentrate, this invention selects the smelting process according to nickel smelting techniques. Since nickel is more easily oxidized than copper, a portion of the nickel exists as oxides in the smelting slag. Oxygen-enriched side-blown smelting (oxygen concentration above 60%) is employed, and reducing coal is added to the smelting furnace to control the degree of oxidation in the smelting slag, which helps to improve the nickel recovery rate during the smelting process.

[0045] During continuous blowing, a shallower blowing depth is controlled to reduce the copper-nickel ratio in the first blowing slag. The endpoint control of the continuous blowing process in this invention differs from traditional copper smelting. Traditional copper smelting involves continuous blowing under oxygen-rich conditions, resulting in crude copper with very low sulfur content (0.01%–0.5%), which can then be directly refined using a (rotary) anode furnace. In this process, continuous blowing yields raw crude copper with a nickel content of 1–3% and a copper content of 85–95%, containing 0.5–3% sulfur. At this point, the Ni content in the blowing slag is 5–9%, and the Cu content is 10–20%, resulting in a low Cu / Ni ratio. This is more conducive to improving the direct copper recovery rate and reducing the system investment and operating costs for recovering nickel from the first blowing slag. Furthermore, at a blowing temperature of 1300–1400°C, the slag can be discharged in liquid form, and there is less adhesion in the furnace. In summary, by controlling the blowing temperature and a shallower blowing depth, continuous blowing of nickel-containing copper matte can be achieved, liquid slag discharge can be realized, and furnace adhesion can be reduced.

[0046] The continuous blowing process employs the following schemes: multi-lance top-blown furnace continuous blowing, oxygen bottom-blown continuous blowing, or flash blowing. The corresponding equipment is a multi-lance top-blown furnace, a bottom-blown furnace, or a flash blowing furnace. Compared with copper concentrate, copper-nickel concentrate has a higher nickel content, and correspondingly, copper matte has a higher nickel content. Therefore, the slag can be subsequently treated with a slag depletion process to recover nickel, thus avoiding the waste of nickel resources.

[0047] In the pyrometallurgical refining process, a bottom-blown refining furnace is used to directly refine the raw copper with a nickel content of 1-3% produced by shallow blowing. This is different from the two-stage blowing process (shallow blowing + deep blowing). It is equivalent to integrating the second stage deep blowing and anode furnace refining into bottom-blown refining furnace refining, which requires fewer furnaces and achieves connection of the melt flow channels in the process. Unlike traditional pyrometallurgical refining of copper, this invention employs a bottom-blown refining furnace with the addition of a small amount of flux such as SiO2. This further removes impurities such as nickel, sulfur, iron, lead, bismuth, antimony, and arsenic from the crude copper, thus meeting the requirements of electrolytic refining for the chemical composition and physical specifications of the anode. Compared to rotary anode furnaces, bottom-blown refining furnaces have greater air supply capacity and stronger impurity removal capabilities, and can relatively efficiently reduce the Ni content in raw crude copper from 1-3% to below 0.5%. For example, Ni content in raw crude copper of 1%, 1.5%, 2%, 2.5%, and 3% can be reduced to approximately 0.5%.

[0048] In some embodiments of the present invention, after smelting and continuous blowing, the process further includes: recovering nickel from the first blowing slag obtained from the blowing process. Specifically, this includes: The first slag produced by continuous blowing is sent to a slag depletion furnace for slag depletion to obtain low-nickel sulfur and depleted slag. The low-nickel-sulfur material is sent to a bottom-blown furnace, i.e., a second blowing furnace, for nickel matte blowing to obtain high-nickel matte and second blowing slag.

[0049] Based on the first smelting slag obtained by controlling the smelting of copper-nickel matte at a lower grade and controlling the smelting of the shallower continuous blowing depth, slag depletion and bottom blowing smelting of nickel matte were carried out to obtain high-nickel matte, achieving high-yield recovery of metallic nickel and reducing nickel recovery costs.

[0050] The slag depletion process utilizes a depletion electric furnace. Unlike traditional nickel smelting depletion furnaces, this process employs a two-stage design: the furnace body is divided into a front depletion zone and a rear settling zone. The first batch of smelting slag enters the depletion zone via a trough and reacts with the added reducing agent, ensuring sufficient reduction of valuable metals. Pyrite is added as a sulfiding agent and diluent to dilute the alloy phase produced in the reduction zone. Furthermore, the depletion zone of the furnace is equipped with pre-drilled side-blowing lance positions. During slag depletion, the side-blowing lances inject additives and / or fuels, such as pulverized coal, natural gas, or sulfur, to further improve the kinetics of the reduction reaction, enhance the reduction sulfidation process, and reduce the nickel content in the slag. The slag produced by the depletion furnace, known as depleted slag, can be slowly cooled, crushed, and then sent to a slag beneficiation system for PGM recovery.

[0051] Nickel matte smelting employs a bottom-blown furnace. Unlike traditional converter nickel matte smelting, bottom-blown furnace smelting reduces SO2 emissions, resulting in better environmental performance. Iron and other impurities in the nickel matte undergo oxidation reactions with the blown-in air, forming a second smelting slag with quartz. This second smelting slag can be returned to the slag depletion step. The high-nickel matte can be air-crushed and sold, or sent for wet leaching to produce industrial-grade nickel sulfate, or slowly cooled and sent to a grinding and flotation system for beneficiation to produce secondary nickel concentrate or secondary copper concentrate.

[0052] In some embodiments of the present invention, the method further includes: sending the slag to a slag beneficiation system to beneficiate and recover PGM, obtaining a slag concentrate containing platinum group metals, and then returning the slag concentrate to the smelting step for platinum group metal enrichment, so as to improve the platinum group metal recovery rate.

[0053] The slag produced during the smelting and slag depletion processes (i.e., smelting slag and depletion slag) contains small amounts of platinum group metals (PGMs). Although the copper content is low, the PGM grade is relatively high (compared to the original crustal ore). By adding a PGM beneficiation process, the PGMs can be recovered and enriched, improving the overall plant recovery rate and economic benefits. Furthermore, slow cooling of the slag before crushing and beneficiation can prevent the precious metals from freezing due to rapid cooling.

[0054] In some embodiments, the process includes: slowly cooling and crushing the depleted slag produced during the slag depletion process, and sending it to a slag beneficiation system to recover platinum group metals, obtaining a second slag tailings and a second slag concentrate containing platinum group metals, and returning the second slag concentrate to the smelting step. Beneficiating the depleted slag improves the recovery rate of copper, nickel, and platinum group metals.

[0055] In some embodiments, the process includes: slowly cooling and crushing the smelting slag produced during the smelting process, and sending it to a slag beneficiation system to recover platinum group metals (PGMs), obtaining a first slag tailings and a first slag concentrate containing PGMs, and returning the first slag concentrate to the smelting step. For smelting slag beneficiation, based on the traditional copper smelting slag beneficiation for copper and nickel recovery, a PGM beneficiation process is added to improve the PGM recovery rate; that is, PGMs are recovered simultaneously with copper and nickel in the beneficiation step, and the resulting slag concentrate containing both copper and nickel and PGMs is returned to the smelting process.

[0056] like Figure 1 As shown in some embodiments of the present invention, the method for processing platinum group metal-rich, low-nickel, high-copper concentrate includes the following steps: 1) The low-nickel, high-copper concentrate is batched and sent to the smelting furnace for smelting, and the copper-nickel matte grade is controlled to produce copper-nickel matte and smelting slag with a grade of 60-70%. The smelting slag is slowly cooled, crushed, and sent to slag beneficiation to recover copper, nickel, and platinum group metals, yielding slag tailings (for sale) and slag concentrate containing platinum group metals. The first slag concentrate is then returned to the smelting step. 2) The copper-nickel matte is fed into a blowing furnace via a trough for continuous blowing. The continuous blowing temperature is controlled at 1300–1400°C, and the continuous blowing depth is controlled to produce blowing slag and raw blister copper containing 1–3% nickel and 85–95% copper. The Ni content in the blowing slag is 5–9%, and the Cu content is 10–20%. 3) The raw copper is fed to the bottom-blown refining furnace through a trough for pyrometallurgical refining to produce anode copper. The anode copper is cast into copper anode plates and sent to electrolysis. The produced refining slag can be cooled, crushed and returned to the smelting or blowing steps. 4) The slag produced by continuous blowing is sent to a slag depletion furnace for slag depletion to obtain low-nickel sulfur and depleted slag; the low-nickel sulfur is sent to a bottom blowing furnace via a trough for nickel matte blowing to obtain high-nickel matte (for sale) and blowing slag; the blowing slag is returned to slag depletion; the depleted slag is slowly cooled, crushed and sent to slag beneficiation to obtain slag tailings (for sale) and slag concentrate containing platinum group metals; the slag concentrate is returned to the smelting step.

[0057] By feeding low-nickel, high-copper concentrate rich in platinum group metals (PGMs) or slag concentrate into the smelting furnace for smelting, the copper-nickel matte grade (Ni+Cu) is controlled below 70%, and the smelting oxygen potential is controlled to ensure that nickel enters the copper matte phase as much as possible, thereby improving the subsequent nickel recovery rate. By slowly cooling and crushing the smelting slag before sending it to slag beneficiation, copper and nickel are recovered, along with PGMs. The PGM-containing slag concentrate is then returned to the smelting furnace for enrichment, further improving the PGM recovery rate.

[0058] By continuously blowing the hot copper-nickel matte into a blowing furnace through a trough at a specific temperature, liquid slag discharge is achieved, reducing furnace adhesion. By controlling the shallow blowing depth, the risk of deep-blown foamy slag is avoided, while continuous blowing of nickel-containing copper matte is achieved. This results in raw blister copper with a nickel content of about 1-3%, a copper content of 85-95%, and 0.5-2% S. The Ni content in the blowing slag is 5-9%, and the Cu content is 10-20%. This reduces the copper-nickel ratio in the blowing slag, increases the direct copper recovery rate, and facilitates the reduction of subsequent nickel recovery.

[0059] By directly feeding the raw copper with a nickel content of 1-3% produced by continuous blowing into the bottom-blown refining furnace for pyrometallurgical refining, impurities can be removed efficiently. The pyrometallurgical refining process undertakes part of the nickel removal task, which can efficiently reduce the nickel content in the anode copper from 1-3% to 0.5%, thus facilitating the subsequent electrolytic refining of copper anode plates. The refining slag produced by pyrometallurgical refining is cooled, crushed, and returned to smelting or blowing to recover the nickel, copper, and platinum group metals.

[0060] By adding the slag obtained from continuous blowing in the smelting furnace to a depletion electric arc furnace for slag depletion, low-nickel matte is produced and transported via a trough to a bottom-blown furnace for nickel matte blowing, thus obtaining high-nickel matte. This achieves high-yield, low-cost nickel recovery. The high-nickel matte is then cooled and sold or further processed. The slag from nickel matte blowing is returned to the depletion electric arc furnace for slag depletion to recover nickel, copper, and platinum group metals. Furthermore, by slowly cooling and crushing the depletion slag from the depletion electric arc furnace before sending it to slag beneficiation, the slag concentrate containing PGM is returned to the smelting furnace for enrichment, thereby improving the platinum group metal recovery rate.

[0061] In summary, compared with traditional copper smelting processes, it has advantages such as high PGM, high nickel recovery rate, high efficiency and short process, and good economic benefits, realizing the comprehensive recovery of multi-metal concentrates rich in platinum group metals, low nickel and high copper.

[0062] The technical solution and effects of the present invention will be described below with reference to specific embodiments: Example 1 A certain copper concentrate from abroad contains 26% Cu, 1.8% Ni, and PGM ≥ 20 g / t. It is a typical low-nickel, high-copper concentrate rich in PGM.

[0063] The selected process flow for copper pyrometallurgical smelting is as follows: copper concentrate — batching — oxygen-enriched side-blown smelting — copper matte multi-lance top-blown continuous smelting — pyrometallurgical refining of crude copper in a bottom-blown refining furnace — anode copper casting.

[0064] The selected process flow for nickel pyrometallurgical smelting is as follows: copper multi-lance top blowing slag smelting in a high-efficiency depletion furnace — nickel matte bottom blowing furnace smelting — high-nickel matte granulation.

[0065] The copper concentrate is processed by the following steps: 1) The copper-nickel matte was smelted in an oxygen-enriched side-blown furnace to control the grade of copper-nickel matte. The grade of the produced copper-nickel matte (Cu+Ni weight percentage) was about 65%, and the smelting slag contained 1.25% Cu and 0.40% Ni. The copper-nickel matte was then fed into a multi-lance top-blown furnace through a trough for continuous blowing at 1350°C. The blowing depth was controlled to be relatively shallow. The resulting raw copper contained 94% Cu and 1.8% Ni, and the resulting smelting slag contained 16% Cu and 7.5% Ni. The raw copper was then fed into a bottom-blown refining furnace through a trough for pyrometallurgical refining. The resulting anode copper contained 98.90% Cu and 0.50% Ni. The anode plates were cast using a disc casting machine and then sent to the electrolysis system for electrolytic refining.

[0066] 2) The slag obtained from continuous blowing is fed into a depletion electric furnace while still hot via a trough. Sulfidating agents and reducing coal are added to deplete the slag in the furnace, resulting in low-nickel matte and depleted slag. The low-nickel matte contains 39% Cu and 18% Ni, while the depleted slag contains 0.30% Cu and 0.14% Ni. The low-nickel matte is then fed into a bottom-blown furnace for nickel matte blowing, yielding high-nickel matte and slag. The high-nickel matte contains 51% Cu, 24% Ni, and 3.5% Fe, while the slag contains 3.0% Cu and 1.0% Ni. The high-nickel matte is granulated by air and sold externally, while the slag is fed into the depletion electric furnace while still hot via a bale.

[0067] 3) Slow cooling and beneficiation of smelting slag, by adding a PGM beneficiation process and returning the slag concentrate to smelting, can achieve PGM enrichment and improve PGM recovery rate.

[0068] Example 2

[0069] The copper pyrometallurgical process in this embodiment includes the following steps: The copper-nickel matte was smelted in an oxygen-enriched side-blown furnace, and the grade of the copper-nickel matte was controlled. The grade of the produced copper-nickel matte was about 60%, and the smelting slag contained 1.10% Cu and 0.20% Ni. The copper-nickel matte was fed into a multi-lance top-blown furnace through a trough for continuous blowing at 1400°C, with a relatively shallow blowing depth. The resulting raw copper contained 90% Cu and 2.5% Ni, while the slag contained 15% Cu and 8.5% Ni. Raw copper is fed into a bottom-blown refining furnace through a trough for pyrometallurgical refining. The resulting anode copper contains 98.80% Cu and 0.45% Ni. The copper anode plate is cast by a disc casting machine and then sent to the electrolysis system for electrolytic refining.

[0070] Example 3

[0071] The nickel pyrometallurgical process flow in this embodiment includes the following steps: The copper-nickel matte was smelted in an oxygen-enriched side-blown furnace, and the grade of the copper-nickel matte was controlled. The grade of the produced copper-nickel matte was about 70%, and the smelting slag contained 1.40% Cu and 0.50% Ni. Copper-nickel matte is fed into a multi-lance top-blown furnace through a trough for continuous blowing at 1350°C. The blowing depth is controlled to be relatively shallow. The resulting raw copper contains 89% Cu and 1.6% Ni, and the blowing slag contains 20% Cu and 10% Ni. Subsequently, the blowing slag is depleted and nickel matte is blown to obtain high-nickel matte.

[0072] Compared with Example 1, Example 3 has a higher grade of copper-nickel matte and a lower iron content. Due to the lower iron content in the copper-nickel matte entering the smelting process, the amount of smelting slag is reduced at the same smelting depth, thus reducing the burden of subsequent slag depletion.

[0073] Comparative Example 1

[0074] The smelting and refining process of this copper concentrate is as follows: The copper-nickel matte was smelted in an oxygen-enriched side-blown furnace to control the grade of copper-nickel matte. The grade of the produced copper-nickel matte was about 65%, and the smelting slag contained 0.4% Ni. The copper-nickel matte was continuously blown, and the blowing depth was controlled to obtain crude copper containing 97% copper and 0.9% nickel. The smelting slag contained 23% copper and 6% nickel.

[0075] Compared to Example 1, Comparative Example 1 has a higher Cu / Ni ratio in the slag, a lower direct copper recovery rate, and increases the system investment and operating costs for recovering nickel from the slag.

[0076] The description of this invention is given for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A process for the treatment of a platinum group metal rich low nickel high copper concentrate characterised in that, include: The copper-nickel concentrate is batched and fed into a smelting furnace for oxygen-enriched side-blown smelting according to the nickel smelting process. Reducing coal is added to the smelting furnace to control the degree of slag oxidation, allowing more nickel from the copper concentrate to enter the copper matte phase, thereby controlling the grade of the copper-nickel matte and producing low-grade copper-nickel matte and smelting slag; wherein the total copper and nickel content in the copper-nickel matte is 60-65%; The copper-nickel matte is conveyed hot to the first smelting furnace via a flow channel. Continuous smelting is performed using a multi-lance top-blown furnace, oxygen bottom-blown continuous smelting, or flash smelting process. The smelting endpoint is controlled to ensure the sulfur content of the raw blister copper is 0.5–3%, reducing the copper-nickel ratio in the smelting slag and thus controlling a shallower continuous smelting depth, producing raw blister copper and the first smelting slag with higher sulfur content. The raw blister copper contains 1–3% nickel and 85–95% copper, while the first smelting slag contains 5–9% nickel and 10–20% copper. The continuous smelting temperature is 1300–1400°C. The raw copper is hot-flowed through a trough to a bottom-blown refining furnace for pyrometallurgical refining and nickel removal to produce anode copper. The anode copper contains no more than 0.5% nickel. The anode copper is then cast into anode plates and sent to the electrolysis process. The first smelting slag is conveyed hot to a depletion electric furnace using a trough for slag depletion, resulting in low-nickel sulfur and depleted slag. The low-nickel sulfur is then conveyed hot to a second smelting furnace using a trough for nickel matte smelting, resulting in high-nickel matte and a second smelting slag. The high-nickel matte is intended for sale, wet processing, or mineral processing.

2. The method for processing platinum group metal-rich, low-nickel, high-copper concentrate according to claim 1, characterized in that, The method further includes: The smelting slag is slowly cooled, crushed, and sent to a slag beneficiation system to recover copper, nickel, and platinum group metals, resulting in the first slag tailings and the first slag concentrate containing platinum group metals. The first slag concentrate is then returned to the smelting furnace for smelting. And / or, the depleted slag is slowly cooled, crushed, and sent to a slag beneficiation system to recover platinum group metals, obtaining a second slag tailings and a second slag concentrate containing platinum group metals, and the second slag concentrate is returned to the smelting furnace for smelting.

3. The method for processing platinum group metal-rich, low-nickel, high-copper concentrate according to claim 1, characterized in that, The slag reduction electric furnace includes a furnace body, which is divided into a front slag reduction zone and a rear settling zone. The side walls of the furnace body in the slag reduction zone are equipped with side-blowing spray guns. During the slag reduction process, additives and / or fuel are sprayed using the side-blowing spray guns.

4. The method for processing platinum group metal-rich, low-nickel, high-copper concentrate according to claim 1, characterized in that, The second blowing furnace is a bottom-blown furnace.

5. The method for processing platinum group metal-rich, low-nickel, high-copper concentrate according to claim 1, characterized in that, In the step of batching copper-nickel concentrate and sending it to the smelting furnace for smelting... The copper concentrate is batched and sent to an oxygen-enriched side-blown smelting furnace for oxygen-enriched side-blown smelting, or the copper concentrate is batched and sent to a bottom-blown smelting furnace for oxygen bottom-blown smelting, or the copper concentrate is batched and sent to a flash smelting furnace for flash smelting.

6. The method for processing platinum group metal-rich, low-nickel, high-copper concentrate according to claim 1, characterized in that, In the step of continuously blowing the copper-nickel matte into the first blowing furnace... The copper-nickel matte is sent to a multi-gun top-blown furnace, bottom-blown furnace, or flash furnace for continuous smelting.

7. The method for processing platinum group metal-rich, low-nickel, high-copper concentrate according to claim 1, characterized in that, During the pyrometallurgical refining process, refining slag is also produced. The method further includes returning the refined slag to the smelting or continuous blowing step.

8. The method for processing platinum group metal-rich, low-nickel, high-copper concentrate according to claim 1, characterized in that, The second blown slag is returned to the depletion furnace in a hot state or in a cooled, solid state via a bun.

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