Low nickel matte smelting method and low nickel matte smelting equipment

Abstract

The invention discloses a low-nickel matte smelting method and low-nickel matte smelting equipment. The smelting method of the low nickel matte comprises the following steps that first-stage blowing is conducted on the low nickel matte through first oxygen-containing gas, first melt and first blowing slag are obtained, primary iron removal is facilitated, and the low nickel matte contains copper, nickel, iron and sulfur; and carrying out second-stage blowing on the first melt by using a second oxygen-containing gas to obtain a second melt and second blowing slag so as to carry out secondary iron removal. The smelting method of the low nickel matte has the advantages of being high in copper and nickel purity, high in copper and nickel recovery rate, low in iron content, low in energy consumption, short in technological process and treatment period, continuous in process, high in safety, stable and controllable in smoke component and the like.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and more specifically, to a method and equipment for smelting low-grade nickel matte. Background Technology

[0002] Low-grade nickel matte can be processed using two methods: converter blowing and wet leaching.

[0003] The converter blowing process has the following disadvantages: (1) low direct metal recovery rate and high copper content in slag, requiring secondary depletion; (2) the converter blowing process requires intermittent operation, resulting in large fluctuations in flue gas volume and sulfur dioxide concentration, which increases the difficulty and cost of flue gas treatment; (3) the converter needs to be frequently started to feed and dump slag, resulting in high air leakage rate and serious low-altitude pollution.

[0004] The wet leaching process has the following disadvantages: (1) It requires pretreatment such as crushing and ball milling of low nickel matte, resulting in a long process flow and long processing cycle; (2) The wet leaching process requires strict control of multiple parameters such as reaction temperature, reaction pressure, and leaching agent concentration, which are harsh and not conducive to stable operation; (3) It generates a large amount of acidic wastewater and waste residue containing heavy metals, which can easily cause secondary pollution. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, this invention proposes a method and equipment for smelting low-grade nickel matte.

[0006] The smelting method for low-grade nickel matte of the present invention includes the following steps: using a first oxygen-containing gas to perform a first-stage blowing process on the low-grade nickel matte to obtain a first melt and a first blowing slag, so as to perform a first de-ironization, wherein the low-grade nickel matte contains copper, nickel, iron and sulfur; and using a second oxygen-containing gas to perform a second-stage blowing process on the first melt to obtain a second melt and a second blowing slag, so as to perform a second de-ironization.

[0007] The low-grade nickel matte smelting method of the present invention has the advantages of high copper and nickel purity, high copper and nickel recovery rate, low iron content, low energy consumption, short process flow and processing cycle, continuous process, high safety, and stable and controllable flue gas composition.

[0008] Optionally, the hot second smelting slag is added to the low-grade nickel matte, and the first oxygen-containing gas is used to perform the first-stage smelting of the low-grade nickel matte and the second smelting slag.

[0009] Optionally, the oxygen concentration of the first oxygen-containing gas is 25 vol%-60 vol%, and the temperature of the first-stage blowing is 1100 degrees Celsius-1300 degrees Celsius; and / or the oxygen concentration of the second oxygen-containing gas is 25 vol%-60 vol%, and the temperature of the second-stage blowing is 1150 degrees Celsius-1300 degrees Celsius.

[0010] Optionally, the oxygen concentration of the first oxygen-containing gas is 30 vol%-55 vol%, and the temperature of the first-stage blowing is 1180 degrees Celsius-1250 degrees Celsius; and / or the oxygen concentration of the second oxygen-containing gas is 30 vol%-50 vol%, and the temperature of the second-stage blowing is 1200 degrees Celsius-1250 degrees Celsius.

[0011] Optionally, the low-grade nickel matte is produced by a fuming furnace and / or a side-blown furnace, and the low-grade nickel matte contains 10wt%-20wt% copper, 5wt%-10wt% nickel, 35wt%-50wt% iron and 20wt%-30wt% sulfur.

[0012] Optionally, the first melt contains 30wt%-45wt% copper, 15wt%-25wt% nickel, 15wt%-20wt% iron and 20wt%-30wt% sulfur; the first blowing slag contains 0.5wt%-0.8wt% copper, 0.3wt%-0.5wt% nickel and 40wt%-50wt% iron.

[0013] Optionally, the second melt contains 45wt%-55wt% copper, 20wt%-30wt% nickel, 2wt%-5wt% iron and 20wt%-30wt% sulfur; the second blowing slag contains 0.6wt%-0.9wt% copper, 1.0wt%-1.3wt% nickel and 40wt%-50wt% iron.

[0014] Optionally, the smelting method for low-grade nickel matte further includes the following steps: cooling the second melt to obtain high-grade nickel matte blocks; crushing and grinding the high-grade nickel matte blocks to obtain high-grade nickel matte fragments; and beneficiating the high-grade nickel matte fragments to obtain copper concentrate, nickel concentrate, and magnetite alloy.

[0015] Optionally, the high-grade nickel matte fragments are classified to obtain a first ore sand and a second ore sand, wherein the particle size of the second ore sand is larger than that of the first ore sand; the second ore sand is subjected to magnetic separation to obtain the magnetic alloy; the first ore sand is subjected to primary flotation to obtain concentrate and tailings; the concentrate is subjected to secondary flotation to obtain copper concentrate and nickel concentrate; and the tailings are scavenged to obtain nickel concentrate.

[0016] The low-grade nickel matte smelting equipment of the present invention includes: a first blowing furnace, the first blowing furnace having a first furnace cavity and a first feed inlet, a first flue gas outlet, a first melt outlet and a first slag outlet communicating with the first furnace cavity; a first oxygen-containing gas lance, the first oxygen-containing gas lance being disposed in the first blowing furnace, the oxygen-containing gas outlet of the first oxygen-containing gas lance communicating with the first furnace cavity; a second blowing furnace, the second blowing furnace having a second furnace cavity and a second feed inlet, a second flue gas outlet, a second melt outlet and a second slag outlet communicating with the second furnace cavity; a second oxygen-containing gas lance, the second oxygen-containing gas lance being disposed in the second blowing furnace, the oxygen-containing gas outlet of the second oxygen-containing gas lance communicating with the second furnace cavity; and a sealed chute, one end of the sealed chute being connected to the first melt outlet and the other end of the sealed chute being connected to the second feed inlet.

[0017] The low-grade nickel matte smelting equipment of the present invention has the advantages of high copper and nickel purity, high copper and nickel recovery rate, low iron content, low energy consumption, short process flow and processing cycle, continuous process, high safety, and stable and controllable flue gas composition. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a low-nickel matte smelting equipment according to an embodiment of the present invention; Figure 2 This is a partial structural schematic diagram of a low-nickel matte smelting equipment according to an embodiment of the present invention; Figure 3 This is a flowchart of a low-grade nickel matte smelting method according to an embodiment of the present invention.

[0019] Figure label: Smelting equipment 100 First blowing furnace 1, first furnace cavity 11, first feed inlet 12, first flue gas outlet 13, first melt outlet 14, first end portion 15, second end portion 16. Second blowing furnace 2, furnace body 21, second furnace cavity 211, second flue gas outlet 212, second melt outlet 213, left end 215, right end 216. Feeding section 22, second feed inlet 221 Support section 23 First oxygen-containing gas spray gun 31, second oxygen-containing gas spray gun 32 4. Sealed chute; 41. Inlet end; 42. Outlet end. 5. Slag return chute, 51. Outlet end First transmission device 61, second transmission device 62 Detailed Implementation Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] The smelting method for low-grade nickel matte according to an embodiment of the present invention includes the following steps: The low-grade nickel matte is smelted using a first oxygen-containing gas to obtain a first melt and a first smelting slag for a first de-ironization process. The low-grade nickel matte contains copper, nickel, iron and sulfur.

[0021] The first melt is subjected to two-stage blowing using a second oxygen-containing gas to obtain a second melt and a second blowing slag, so as to carry out secondary de-ironization.

[0022] The low-nickel matte smelting method according to embodiments of the present invention does not require pretreatment of the low-nickel matte, such as crushing or ball milling. The low-nickel matte can be directly smelted, which not only effectively shortens the process flow and processing cycle and effectively reduces material turnover energy consumption, but also effectively increases the flexibility to deal with different nickel-containing materials.

[0023] By performing a two-stage blowing process on the first melt, the fuel consumption from cooling and remelting intermediate products is avoided. This allows the smelting method for low-grade nickel matte to have advantages such as continuous process, high safety, stable and controllable flue gas composition, and lower investment in supporting flue gas treatment equipment.

[0024] Furthermore, by performing a two-stage blowing process to achieve secondary de-ironization, the iron content of the second melt can be significantly reduced, resulting in high-grade nickel matte. This facilitates subsequent copper-nickel separation, thereby improving the purity and quality of copper and nickel products and increasing their recovery rates.

[0025] The smelting method for low-grade nickel matte according to embodiments of the present invention makes full use of the heat from the oxidation of Fe in low-grade nickel matte in order to achieve self-heating, thereby significantly reducing fuel consumption.

[0026] Therefore, the low-grade nickel matte smelting method according to the embodiments of the present invention has the advantages of high copper and nickel purity, high copper and nickel recovery rate, low iron content, low energy consumption, short process flow and processing cycle, continuous process, high safety, and stable and controllable flue gas composition.

[0027] Low-grade nickel matte can be produced by a fuming furnace or by other furnace types such as a side-blown furnace. The low-grade nickel matte smelting method of the present invention has the advantage of a wide range of raw material (low-grade nickel matte) sources and can process different nickel-containing materials.

[0028] Optionally, low-grade nickel matte contains copper, nickel, iron, and sulfur. For example, low-grade nickel matte contains 10wt%-20wt% copper, 5wt%-10wt% nickel, 35wt%-50wt% iron, and 20wt%-30wt% sulfur.

[0029] The low-grade nickel matte is smelted using a first-stage blowing process with an oxygen-containing gas. The oxygen concentration of the first-stage blowing gas is 25 vol%-60 vol%. This effectively oxidizes the iron in the low-grade nickel matte, thereby reducing the iron content. The temperature of the first-stage blowing is 1100-1300 degrees Celsius. During the first-stage blowing process, an appropriate amount of quartz can be added as a slagging agent.

[0030] Optionally, the oxygen concentration of the first oxygen-containing gas is 30 vol%-55 vol%. This allows for more effective oxidation of the iron in the low-grade nickel matte, thereby further reducing the iron content. Optionally, the temperature of the first-stage blowing is 1180-1250 degrees Celsius.

[0031] By performing a single-stage refining process on low-grade nickel matte, a first melt and a first refining slag are obtained for primary deironization. The first melt contains 30wt%-45wt% copper, 15wt%-25wt% nickel, 15wt%-20wt% iron, and 20wt%-30wt% sulfur. The first refining slag contains 0.5wt%-0.8wt% copper, 0.3wt%-0.5wt% nickel, and 40wt%-50wt% iron.

[0032] The first blown slag is slowly cooled, and then the cooled first blown slag is beneficiated to obtain tailings and nickel-copper concentrate.

[0033] The first melt is subjected to a two-stage blowing process using a second oxygen-containing gas. The oxygen concentration of the second oxygen-containing gas is 25 vol%-60 vol%. This effectively oxidizes the iron in the first melt, thereby reducing the iron content. The temperature of the two-stage blowing is 1150-1300 degrees Celsius.

[0034] Optionally, the oxygen concentration of the second oxygen-containing gas is 30 vol%-50 vol%. This allows for more effective oxidation of the iron in the first melt, thereby further reducing the iron content. Optionally, the temperature of the second-stage blowing is 1200-1250 degrees Celsius.

[0035] By subjecting the first melt to two-stage blowing, a second melt and a second blowing slag can be obtained for secondary deironization. The second melt contains 45wt%-55wt% copper, 20wt%-30wt% nickel, 2wt%-5wt% iron, and 20wt%-30wt% sulfur. The second blowing slag contains 0.6wt%-0.9wt% copper, 1.0wt%-1.3wt% nickel, and 40wt%-50wt% iron.

[0036] Optionally, the hot second smelting slag is added to low-grade nickel matte, and the low-grade nickel matte and the second smelting slag are smelted using a first oxygen-containing gas. This allows for the recovery of copper and nickel from the second smelting slag, thereby increasing the direct recovery rate of copper and nickel from the low-grade nickel matte.

[0037] Moreover, compared with one-step refining (which yields high-grade nickel matte with only one refining operation), the oxygen content of the first refining slag can be reduced by performing one-stage and two-stage refining, thereby improving the beneficiation effect of the first refining slag.

[0038] like Figure 3 As shown, the flue gas generated in the first stage of smelting can be recycled for waste heat recovery in a boiler to generate steam for power generation. A dust collector is then used to collect dust from the flue gas, yielding dust-removed flue gas and flue dust. Low-grade nickel matte can be added to the flue dust, and a first oxygen-containing gas is used to perform a first-stage smelting process on the low-grade nickel matte, the second smelting slag, and the flue dust. This allows for the recovery of copper and nickel from the flue dust, thereby further improving the copper and nickel recovery rate of the low-grade nickel matte.

[0039] The flue gas produced in the second stage of refining and the aforementioned dust-collected flue gas can be used to produce sulfuric acid. The flue gas produced in the first stage of refining contains 10 vol%-15 vol% sulfur dioxide. The flue gas produced in the second stage of refining contains 3 vol%-10 vol% sulfur dioxide.

[0040] like Figure 3 As shown, the second melt is cooled to obtain high-grade nickel matte. Optionally, the second melt is slowly cooled so that no cooling medium is required. For example, the second melt is slowly cooled for 96 to 120 hours.

[0041] The high-grade nickel matte blocks are then crushed and ground to obtain high-grade nickel matte fragments. These fragments are then beneficiated to obtain copper concentrate, nickel concentrate, and magnetite alloy.

[0042] like Figure 3 As shown, high-grade nickel matte fragments are graded to obtain a first ore sand and a second ore sand. The particle size of the second ore sand is larger than that of the first ore sand. For example, the first ore sand can be fine-grained ore sand, and the second ore sand can be coarse-grained ore sand.

[0043] Optionally, the second ore is subjected to magnetic separation to obtain a magnetic alloy. The first ore is subjected to primary flotation to obtain concentrate and tailings. The concentrate is subjected to secondary flotation to obtain copper concentrate and nickel concentrate, and the tailings are scavenged to obtain nickel concentrate. The copper concentrate and nickel concentrate can be sold externally, while the magnetic alloy is sent as a high-value material to a copper anode furnace for refining to further recover copper, nickel, and precious metals.

[0044] Example 1: 8.3 t / h of low-grade nickel matte (Cu: 16.3 wt%, Ni: 6.6 wt%, Fe: 45.3 wt%, S: 22.5 wt%) produced by the fuming furnace is added to the first blowing furnace 1. First oxygen-containing gas (concentration of 31.7 vol%) is blown in through the first oxygen-containing gas lance 31 for a first-stage blowing process, with the temperature controlled at 1220℃. Quartz (2.7 t / h) is added as a slagging agent to generate the first melt (Cu: 40.9 wt%, Ni: 16.1 wt%, Fe: 18.0 wt%, S: 22.0 wt%), the first blowing slag (Cu: 0.6 wt%, Ni: 0.4 wt%, Fe: 42.76 wt%), and S-containing flue gas (output: 8000.9 Nm³). 3 / h, SO2 concentration: 10.2 vol%, dust content: 0.01 g / Nm³ 3 / h). The first melt is sent to the second blowing furnace 2 via a closed chute 4. The first blowing slag is slowly cooled and then sent to the slag flotation system to recover residual copper and nickel. The flue gas is used to generate steam and electricity in a waste heat boiler, and then purified by an electrostatic precipitator before entering the acid production process.

[0045] A second oxygen-containing gas (concentration of 30 vol%) is blown into the second blowing furnace 2 through a second oxygen-containing gas lance 32 for two-stage blowing, with the temperature controlled at 1200℃. This produces a second melt (high-nickel matte) (Cu: 52.73 wt%, Ni: 20.27 wt%, Fe: 3.12 wt%, S: 22.2 wt%), a second blowing slag (Cu: 0.8 wt%, Ni: 1.2 wt%, Fe: 47.4 wt%), and S-containing flue gas (yield: 2945.49 Nm³). 3 / h, SO2 concentration: 3.73 vol%), the second blowing slag is returned to the first blowing furnace 1 in hot form for a first blowing stage, and the flue gas enters the acid production process.

[0046] The second melt produced from the two-stage blowing process is slowly cooled in a slow cooling pit for 96 hours to obtain high-grade nickel matte. After crushing and grinding, the high-grade nickel matte is subjected to flotation, scavenging, and magnetic separation to obtain copper concentrate, nickel concentrate, and magnetic alloy. The overall recovery rate of Cu is 97.1%, and the overall recovery rate of Ni is 96.2%.

[0047] Example 2: 20.8 t / h of low-grade nickel matte (Cu: 17.3 wt%, Ni: 7.1 wt%, Fe: 44.2 wt%, S: 20.0 wt%) produced by the fuming furnace is added to the first blowing furnace 1. First oxygen-containing gas (concentration of 44.1 vol%) is blown in through the first oxygen-containing gas lance 31 for a first-stage blowing process, with the temperature controlled at 1200℃. Quartz (6.86 t / h) is added as a slagging agent to generate the first melt (Cu: 40.9 wt%, Ni: 16.3 wt%, Fe: 18.5 wt%, S: 22.3 wt%), the first blowing slag (Cu: 0.62 wt%, Ni: 0.43 wt%, Fe: 41.08 wt%), and S-containing flue gas (output: 13940 Nm³). 3 SO2 concentration: 12.6 vol%, dust content: 0.02 g / Nm³ 3 / h). The first melt is sent to the second blowing furnace 2 via a closed chute 4. The first blowing slag is slowly cooled and then sent to the slag flotation system to recover residual copper and nickel. The flue gas is used to generate steam and electricity in a waste heat boiler, and then purified by an electrostatic precipitator before entering the acid production process.

[0048] A second oxygen-containing gas (concentration of 32 vol%) is blown into the second blowing furnace 2 through a second oxygen-containing gas lance 32 for two-stage blowing, with the temperature controlled at 1210℃. This produces a second melt (high-nickel matte) (Cu: 51.8 wt%, Ni: 21.2 wt%, Fe: 3.2 wt%, S: 22.5 wt%), a second blowing slag (Cu: 0.8 wt%, Ni: 1.25 wt%, Fe: 46.9 wt%), and S-containing flue gas (output: 4203.5 Nm³). 3 / h, SO2 concentration: 6.18 vol%), the second blowing slag is returned to the first blowing furnace 1 in hot form for a first blowing stage, and the flue gas enters the acid production process.

[0049] The second melt produced from the two-stage blowing process is slowly cooled in a slow cooling pit for 120 hours to obtain high-grade nickel matte. After crushing and grinding, the high-grade nickel matte is subjected to flotation, scavenging, and magnetic separation to obtain copper concentrate, nickel concentrate, and magnetic alloy. The overall recovery rate of Cu is 96.5%, and the overall recovery rate of Ni is 96.3%.

[0050] Example 3: 8.3 t / h of low-grade nickel matte (Cu: 16.3 wt%, Ni: 6.6 wt%, Fe: 45.3 wt%, S: 22.5 wt%) produced by the fuming furnace is added to the first blowing furnace 1. A first oxygen-containing gas (concentration of 25 vol%) is blown in through the first oxygen-containing gas lance 31 for a first-stage blowing process, with the temperature controlled at 1100℃. Quartz (2.7 t / h) is added as a slagging agent to generate the first melt (Cu: 40.7 wt%, Ni: 15.8 wt%, Fe: 18.3 wt%, S: 22.0 wt%), the first blowing slag (Cu: 0.8 wt%, Ni: 0.5 wt%, Fe: 43.8 wt%), and S-containing flue gas (output: 8000.9 Nm³). 3 / h, SO2 concentration: 10.2 vol%, dust content: 0.01 g / Nm³ 3 / h). The first melt is sent to the second blowing furnace 2 via a closed chute 4. The first blowing slag is slowly cooled and then sent to the slag flotation system to recover residual copper and nickel. The flue gas is used to generate steam and electricity in a waste heat boiler, and then purified by an electrostatic precipitator before entering the acid production process.

[0051] A second oxygen-containing gas (concentration of 25 vol%) is blown into the second blowing furnace 2 through a second oxygen-containing gas lance 32 for two-stage blowing, with the temperature controlled at 1150℃. This produces a second melt (high-nickel matte) (Cu: 51.3 wt%, Ni: 19.9 wt%, Fe: 4.09 wt%, S: 22.2 wt%), a second blowing slag (Cu: 0.9 wt%, Ni: 1.3 wt%, Fe: 48.9 wt%), and S-containing flue gas (output: 2945.49 Nm³). 3 / h, SO2 concentration: 3.73 vol%), the second blowing slag is returned to the first blowing furnace 1 in hot form for a first blowing stage, and the flue gas enters the acid production process.

[0052] The second melt produced from the two-stage blowing process is slowly cooled in a slow cooling pit for 96 hours to obtain high-grade nickel matte. After crushing and grinding, the high-grade nickel matte is subjected to flotation, scavenging, and magnetic separation to obtain copper concentrate, nickel concentrate, and magnetic alloy. The overall recovery rate of Cu is 96.1%, and the overall recovery rate of Ni is 95.8%.

[0053] Example 4: 8.3 t / h of low-grade nickel matte (Cu: 16.3 wt%, Ni: 6.6 wt%, Fe: 45.3 wt%, S: 22.5 wt%) produced by the fuming furnace is added to the first blowing furnace 1. A first oxygen-containing gas (60 vol%) is blown in through the first oxygen-containing gas lance 31 for a first-stage blowing process, with the temperature controlled at 1300℃. Quartz (2.7 t / h) is added as a slagging agent to generate the first melt (Cu: 41.4 wt%, Ni: 16.3 wt%, Fe: 17.5 wt%, S: 22.0 wt%), the first blowing slag (Cu: 0.5 wt%, Ni: 0.3 wt%, Fe: 43.1 wt%), and S-containing flue gas (output: 8000.9 Nm³). 3 / h, SO2 concentration: 10.2 vol%, dust content: 0.01 g / Nm³ 3 / h). The first melt is sent to the second blowing furnace 2 via a closed chute 4. The first blowing slag is slowly cooled and then sent to the slag flotation system to recover residual copper and nickel. The flue gas is used to generate steam and electricity in a waste heat boiler, and then purified by an electrostatic precipitator before entering the acid production process.

[0054] A second oxygen-containing gas (60 vol%) is blown into the second blowing furnace 2 through a second oxygen-containing gas lance 32 for two-stage blowing, with the temperature controlled at 1300℃. This produces a second melt (high-nickel matte) (Cu: 53.1 wt%, Ni: 20.58 wt%, Fe: 2.84 wt%, S: 22.2 wt%), a second blowing slag (Cu: 0.6 wt%, Ni: 1.0 wt%, Fe: 47.9 wt%), and S-containing flue gas (yield: 2945.49 Nm³). 3 / h, SO2 concentration: 3.73 vol%), the second blowing slag is returned to the first blowing furnace 1 in hot form for a first blowing stage, and the flue gas enters the acid production process.

[0055] The second melt produced from the two-stage blowing process is slowly cooled in a slow cooling pit for 96 hours to obtain high-grade nickel matte. After crushing and grinding, the high-grade nickel matte is subjected to flotation, scavenging, and magnetic separation to obtain copper concentrate, nickel concentrate, and magnetic alloy. The overall recovery rate of Cu is 97.6%, and the overall recovery rate of Ni is 96.4%.

[0056] The following description, with reference to the accompanying drawings, describes a low-nickel matte smelting apparatus 100 according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, the low-grade nickel matte smelting equipment 100 according to an embodiment of the present invention includes a first blowing furnace 1, a first oxygen-containing gas lance 31, a second blowing furnace 2, a second oxygen-containing gas lance 32, and a closed chute 4.

[0057] The first blowing furnace 1 has a first furnace cavity 11, a first feed inlet 12, a first flue gas outlet 13, a first melt outlet 14, and a first slag outlet. The first feed inlet 12, the first flue gas outlet 13, the first melt outlet 14, and the first slag outlet are all connected to the first furnace cavity 11. A first oxygen-containing gas lance 31 is provided in the first blowing furnace 1, and the oxygen-containing gas outlet of the first oxygen-containing gas lance 31 is connected to the first furnace cavity 11.

[0058] The second blowing furnace 2 has a second furnace chamber 211, a second feed inlet 221, a second flue gas outlet 212, a second melt outlet 213, and a second slag outlet. The second feed inlet 221, the second flue gas outlet 212, the second melt outlet 213, and the second slag outlet are all connected to the second furnace chamber 211. A second oxygen-containing gas lance 32 is installed in the second blowing furnace 2, and its oxygen-containing gas outlet is connected to the second furnace chamber 211. The inlet end 41 of the sealed chute 4 is connected to the first melt outlet 14, and the outlet end 42 of the sealed chute 4 is connected to the second feed inlet 221.

[0059] When smelting low-grade nickel matte using smelting equipment 100, the low-grade nickel matte is added into the first furnace chamber 11 through the first feed port 12. Oxygen-containing gas is supplied into the first furnace chamber 11 through the first oxygen-containing gas lance 31 so as to perform a first-stage blowing process on the low-grade nickel matte in the first furnace chamber 11 to obtain the first melt and the first blowing slag.

[0060] The first melt enters the second furnace chamber 211 sequentially through the first melt outlet 14, the sealed chute 4, and the second feed inlet 221. Oxygen-containing gas is supplied into the second furnace chamber 211 through the second oxygen-containing gas lance 32, so as to perform two-stage blowing of the first melt in the second furnace chamber 211 to obtain the second melt and the second blowing slag.

[0061] The low-nickel matte smelting equipment 100 according to the present invention does not require pretreatment of the low-nickel matte, such as crushing or ball milling. It can directly smelt the low-nickel matte, thereby not only effectively shortening the process flow and processing cycle and effectively reducing material turnover energy consumption, but also effectively increasing the flexibility to deal with different nickel-containing materials.

[0062] By setting up a sealed chute 4 and a second blowing furnace 2, the first melt can be smelted in two stages, thus avoiding the fuel consumption of cooling and remelting intermediate products. This allows the low-grade nickel matte smelting equipment 100 to have advantages such as continuous process, high safety, stable and controllable flue gas composition, and lower investment in supporting flue gas treatment equipment.

[0063] Furthermore, by setting up a closed chute 4 and a second blowing furnace 2 for two-stage blowing, secondary de-ironization can be performed, which can greatly reduce the iron content of the second melt to obtain high-grade nickel matte. This is beneficial for subsequent copper-nickel separation, thereby improving the purity and quality of copper and nickel products and increasing the recovery rate of copper and nickel.

[0064] The low-grade nickel matte smelting apparatus 100 according to an embodiment of the present invention makes full use of the heat from the oxidation of Fe in low-grade nickel matte in order to achieve self-heating, thereby significantly reducing fuel consumption.

[0065] Therefore, the low-grade nickel matte smelting equipment 100 according to the embodiments of the present invention has the advantages of high copper and nickel purity, high copper and nickel recovery rate, low iron content, low energy consumption, short process flow and processing cycle, continuous process, high safety, and stable and controllable flue gas composition.

[0066] like Figure 1 and Figure 2 As shown, the low-grade nickel matte smelting equipment 100 includes a first blowing furnace 1, a first oxygen-containing gas lance 31, a second blowing furnace 2, a second oxygen-containing gas lance 32, and a closed chute 4.

[0067] The first blowing furnace 1 is a horizontal furnace, an inclined horizontal furnace, a vertical furnace, or a tilting furnace, and the second blowing furnace 2 is a horizontal furnace, an inclined horizontal furnace, a vertical furnace, or a tilting furnace.

[0068] like Figure 1 As shown, the first blowing furnace 1 is a horizontal rotary furnace, and the second blowing furnace 2 is a horizontal rotary furnace. The first blowing furnace 1 is rotated by the first transmission device 61, and the second blowing furnace 2 is rotated by the second transmission device 62.

[0069] like Figure 1 As shown, the first feed inlet 12 is located between the first melt outlet 14 and the first smoke outlet 13 in the length direction of the first blowing furnace 1.

[0070] Optionally, the first blowing furnace 1 has a first end 15 and a second end 16 opposite each other in its length direction. A first melt outlet 14 is located at the first end 15 (e.g., the right end) of the first blowing furnace 1, and a first flue gas outlet 13 is located at the second end 16 (e.g., the left end) of the first blowing furnace 1. A first feed inlet 12 is located at the top of the first blowing furnace 1, and the first feed inlet 12 is generally located in the middle of the first blowing furnace 1 in its length direction.

[0071] like Figure 1 As shown, the second flue gas outlet 212 is located between the second feed inlet 221 and the second melt outlet 213 in the length direction of the second blowing furnace 2.

[0072] Optionally, the second blowing furnace 2 has a first end and a second end opposite to each other in its length direction. The second feed inlet 221 is located at the first end (e.g., the left end) of the second blowing furnace 2, and the second melt outlet 213 is located at the second end (e.g., the right end) of the second blowing furnace 2. This prevents the first melt from interfering with the second melt exiting the second furnace cavity 211 through the second melt outlet 213 when the first melt enters the second furnace cavity 211 through the second feed inlet 221. The second flue gas outlet 212 is adjacent to the second feed inlet 221 in the length direction of the second blowing furnace 2.

[0073] like Figure 1 As shown, the first oxygen-containing gas lance 31 is disposed at the bottom of the first blowing furnace 1 to form a bottom-blowing lance. The first oxygen-containing gas lance 31 can also be disposed on the side of the first blowing furnace 1 to form a side-blowing lance. In addition, the first oxygen-containing gas lance 31 can also be disposed at the top of the first blowing furnace 1 to form a top-blowing lance.

[0074] Optionally, multiple first oxygen-containing gas lances 31 are provided, spaced apart at the bottom of the first smelting furnace 1 along its length. This allows for the supply of more oxygen-containing gas into the first furnace chamber 11, thereby improving the primary smelting of low-grade nickel matte, more fully oxidizing the iron in the low-grade nickel matte, and reducing the iron content of the first melt. Furthermore, by providing multiple first oxygen-containing gas lances 31, the oxygen-containing gas can be supplied more evenly.

[0075] like Figure 1 As shown, the second oxygen-containing gas lance 32 is disposed at the bottom of the second blowing furnace 2 to form a bottom-blowing lance. The second oxygen-containing gas lance 32 can also be disposed on the side of the second blowing furnace 2 to form a side-blowing lance. In addition, the second oxygen-containing gas lance 32 can also be disposed at the top of the second blowing furnace 2 to form a top-blowing lance.

[0076] Optionally, there are multiple second oxygen-containing gas lances 32, which are spaced apart at the bottom of the second blowing furnace 2 along the length of the second blowing furnace 2.

[0077] This allows for the supply of more oxygen-containing gas into the second furnace chamber 211, thus enabling better two-stage blowing of the first melt, more thorough oxidation of the iron in the first melt, and a reduction in the iron content of the second melt. Furthermore, by setting up multiple second oxygen-containing gas lances 32, the oxygen-containing gas can be supplied more evenly.

[0078] like Figure 1 As shown, the low-grade nickel matte smelting equipment 100 also includes a slag return chute 5. The inlet end of the slag return chute 5 is connected to the second slag discharge port, and the outlet end 51 of the slag return chute 5 is connected to the first smoke outlet 13. The second smelting slag enters the first furnace chamber 11 sequentially through the second slag discharge port, the slag return chute 5, and the first smoke outlet 13.

[0079] This allows for the use of oxygen-containing gas in a single-stage refining process on low-grade nickel matte and the second-stage slag, enabling the recovery of copper and nickel from the second-stage slag and thus improving the direct recovery rate of copper and nickel from low-grade nickel matte. Furthermore, compared to a single-stage refining process (where high-grade nickel matte is obtained with only one refining operation), the oxygen content of the first-stage slag can be reduced through a single-stage and two-stage refining process, thereby improving the beneficiation efficiency of the first-stage slag.

[0080] like Figure 1 and Figure 2 As shown, the first melt outlet 14 is located above the second feed inlet 221, and the inlet end 41 of the sealed chute 4 is located above the outlet end 42 of the sealed chute 4. This allows the first melt to flow within the sealed chute 4 under its own gravity, thus making it easier and smoother for the first melt to flow into the second furnace chamber 211.

[0081] like Figure 1 and Figure 2 As shown, the second blowing furnace 2 includes a furnace body 21 and a feeding section 22. The furnace body 21 has a second furnace cavity 211, a second flue gas outlet 212, a second melt outlet 213, and a second slag outlet. A second oxygen-containing gas lance 32 is disposed in the furnace body 21. The feeding section 22 is disposed in the furnace body 21. The feeding section 22 has a second feed inlet 221, the upper end of which is open. The outlet end 42 of the sealed chute 4 overlaps the upper surface of the feeding section 22 to communicate with the second feed inlet 221.

[0082] By providing a feeding section 22 on the furnace body 21, and having a second feeding port 221 open at the top, it is possible not only to more easily connect the outlet end 42 of the sealed chute 4 to the second feeding port 221, but also to allow the sealed chute 4 to overlap with the feeding section 22, thereby making the structure of the smelting equipment 100 more stable. (Up and down direction as follows) Figure 1 and Figure 2 As shown by arrow B in the diagram.

[0083] Optionally, the feed section 22 is located at the end of the furnace body 21. This makes it easier for the outlet end 42 of the sealed chute 4 to be connected to the feed section 22.

[0084] like Figure 1 and Figure 2 As shown, the first blowing furnace 1 and the second blowing furnace 2 are spaced apart along the left-right direction, with the second blowing furnace 2 located to the right of the first blowing furnace 1. The length direction of the first blowing furnace 1 is consistent with the left-right direction, and the length direction of the furnace body 21 (the second blowing furnace 2) is also consistent with the left-right direction. The left-right direction is as follows... Figure 1 As shown by arrow A in the diagram.

[0085] The first melt outlet 14 is located at the right end of the first blowing furnace 1. The feed section 22 is located at the left end 215 of the furnace body 21, and the second melt outlet 213 is located at the right end 216 of the furnace body 21.

[0086] like Figure 1 and Figure 2 As shown, the second blowing furnace 2 also includes a support part 23. The side of the support part 23 is connected to the furnace body 21, and the upper surface of the support part 23 is connected to the lower surface of the feed part 22. By providing the support part 23, the feed part 22 can be more stably set on the furnace body 21, thereby making the sealed chute 4 more stably connected to the feed part 22, so as to make the structure of the smelting equipment 100 more stable.

[0087] In addition, the smelting equipment 100 may also include a support platform, on which the sealed chute 4 is supported, so as to make the sealed chute 4 more stable, thereby making the structure of the smelting equipment 100 more stable.

[0088] The low-grade nickel matte smelting method and equipment of this invention precisely control the iron content in high-grade nickel matte, resulting in high-grade nickel matte, which is beneficial for subsequent copper-nickel separation and improves the purity and quality of copper-nickel products. The hot return of the secondary blowing slag to the primary blowing stage achieves efficient resource utilization.

[0089] The low-grade nickel matte smelting method and equipment of the present invention have the following advantages: (1) It has strong process adaptability and high raw material flexibility. The raw materials do not need to be pretreated and can be directly put into the furnace for blowing, which effectively reduces the energy consumption of material turnover. (2) High metal recovery rate, high value of precious metals in magnet alloys and low energy consumption, high direct recovery rate of copper and nickel, copper and nickel recovery rate greater than 95%, making full use of the heat of Fe oxidation in low nickel matte to achieve self-heating, and significantly reducing fuel consumption of low nickel matte treatment.

[0090] (3) The process is continuous, safe, and environmentally friendly. The low-altitude SO2 emission is close to zero, the flue gas composition is stable and controllable, and the investment in supporting flue gas treatment equipment is relatively low.

[0091] (4) The design of the two-stage series blowing furnace avoids the fuel consumption of cooling and remelting intermediate products.

[0092] (5) The grinding-float-magnetic separation collaborative design allows high-grade nickel matte to be slowly cooled, crushed, ground, floated and magnetically separated, producing copper concentrate, nickel concentrate and precious metal-containing magnetic alloys that can be sold in one step, realizing seamless connection between "furnace smelting-mineral beneficiation" and shortening the process flow.

[0093] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0094] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0095] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0096] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0097] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0098] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for smelting low-grade nickel matte, characterized in that, Includes the following steps: The low-grade nickel matte is subjected to a first-stage blowing process using a first oxygen-containing gas to obtain a first melt and a first blowing slag, in order to perform a first-stage de-ironization. The low-grade nickel matte contains copper, nickel, iron and sulfur. and The first melt is subjected to two-stage blowing using a second oxygen-containing gas to obtain a second melt and a second blowing slag, so as to carry out secondary de-ironization.

2. The smelting method for low-grade nickel matte according to claim 1, characterized in that, The hot second smelting slag is added to the low-grade nickel matte, and the first oxygen-containing gas is used to perform the first-stage smelting on the low-grade nickel matte and the second smelting slag.

3. The smelting method for low-grade nickel matte according to claim 1 or 2, characterized in that, The oxygen concentration of the first oxygen-containing gas is 25 vol%-60 vol%, and the temperature of the first-stage blowing is 1100 degrees Celsius-1300 degrees Celsius; and / or The oxygen concentration of the second oxygen-containing gas is 25 vol%-60 vol%, and the temperature of the second-stage blowing is 1150 degrees Celsius-1300 degrees Celsius.

4. The smelting method for low-grade nickel matte according to claim 3, characterized in that, The oxygen concentration of the first oxygen-containing gas is 30 vol%-55 vol%, and the temperature of the first-stage blowing is 1180 degrees Celsius-1250 degrees Celsius; and / or The oxygen concentration of the second oxygen-containing gas is 30 vol%-50 vol%, and the temperature of the second-stage blowing is 1200 degrees Celsius-1250 degrees Celsius.

5. The smelting method for low-grade nickel matte according to claim 1 or 2, characterized in that, The low-grade nickel matte is produced by a fuming furnace and / or a side-blown furnace, and contains 10wt%-20wt% copper, 5wt%-10wt% nickel, 35wt%-50wt% iron and 20wt%-30wt% sulfur.

6. The smelting method for low-grade nickel matte according to claim 1 or 2, characterized in that, The first melt contains 30wt%-45wt% copper, 15wt%-25wt% nickel, 15wt%-20wt% iron and 20wt%-30wt% sulfur; The first blown slag contains 0.5wt%-0.8wt% copper, 0.3wt%-0.5wt% nickel and 40wt%-50wt% iron.

7. The smelting method for low-grade nickel matte according to claim 1 or 2, characterized in that, The second melt contains 45wt%-55wt% copper, 20wt%-30wt% nickel, 2wt%-5wt% iron and 20wt%-30wt% sulfur; The second smelting slag contains 0.6wt%-0.9wt% copper, 1.0wt%-1.3wt% nickel and 40wt%-50wt% iron.

8. The smelting method for low-grade nickel matte according to claim 1 or 2, characterized in that, It also includes the following steps: The second melt is cooled to obtain high-grade nickel matte. The high-grade nickel matte block is crushed and ground to obtain high-grade nickel matte fragments; and The high-grade nickel matte fragments are beneficiated to obtain copper concentrate, nickel concentrate, and magnetite alloy.

9. The smelting method for low-grade nickel matte according to claim 8, characterized in that, The high-grade nickel matte fragments are graded to obtain a first ore sand and a second ore sand, wherein the particle size of the second ore sand is larger than that of the first ore sand. The second ore sand is subjected to magnetic separation to obtain the magnetic alloy; The first ore sand is subjected to one flotation to obtain concentrate and tailings; The concentrate is subjected to secondary flotation to obtain the copper concentrate and the nickel concentrate, and the tailings are scavenged to obtain the nickel concentrate.

10. A low-nickel matte smelting apparatus, characterized in that, include: The first blowing furnace has a first furnace cavity and a first feed inlet, a first flue gas outlet, a first melt outlet and a first slag outlet communicating with the first furnace cavity; The first oxygen-containing gas lance is located in the first blowing furnace, and the oxygen-containing gas outlet of the first oxygen-containing gas lance is connected to the first furnace cavity. The second blowing furnace has a second furnace cavity and a second feed port, a second smoke outlet, a second melt outlet and a second slag outlet communicating with the second furnace cavity; The second oxygen-containing gas lance is located in the second blowing furnace, and the oxygen-containing gas outlet of the second oxygen-containing gas lance is connected to the second furnace cavity. and A sealed chute, one end of which is connected to the first melt outlet and the other end of which is connected to the second feed inlet.

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