Method for extracting iron and nickel by comprehensively recycling nickel smelting slag through carbonylation metallurgy

Abstract

The invention discloses a method for extracting iron and nickel by comprehensively recycling nickel smelting slag through carbonylation metallurgy, which specifically comprises the following steps: 1) carrying out reduction treatment on the nickel smelting slag to obtain a metal alloy; (2) the metal alloy is subjected to powder processing, so that metal alloy powder is obtained; (3) the metal alloy powder is treated through a mineral processing technology, so that metal alloy concentrate and tailings are obtained; 4) activating the metal alloy concentrate to obtain activated metal alloy powder; (5) the activated metal alloy powder reacts with carbon monoxide in a pressurized container, and a nickel carbonyl, carbonyl iron and carbon monoxide mixture and carbonylation tailings are obtained; and 6) carrying out subsequent condensation-rectification-decomposition treatment on the mixture of carbonyl nickel, carbonyl iron and carbon monoxide to obtain carbonyl nickel powder, carbonyl iron powder and carbon monoxide. According to the method, the high-purity carbonyl nickel powder can be extracted from the stockpiled nickel smelting slag, and high-valued application of iron can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of powder metallurgy, and in particular to a method for comprehensively recycling nickel smelting slag by carbonylation metallurgy to extract iron and nickel. Background Art

[0002] Carbonylation metallurgy technology belongs to the field of gas phase metallurgy. This technology mainly uses the reaction of metals and carbon monoxide (CO) at specific temperature and pressure to generate volatile metal carbonyl complexes. The metal carbonyl complexes have different boiling points, and the metal complexes are distilled and purified and then thermally decomposed to obtain products. Compared with traditional pyrometallurgy and hydrometallurgy, carbonylation metallurgy can more efficiently extract high-purity metals from complex ores or waste slags. The carbonylation process has a very high degree of selective separation of metals, which is very conducive to promoting the green development of the industry.

[0003] At present, nickel slag is mainly stored in piles, resulting in serious idle waste of rich iron resources and other valuable metal elements. At the same time, slag piles occupy a large amount of land and cause a series of problems such as environmental pollution, which seriously affect and restrict the healthy development of enterprises.

[0004] The carbonylation process for treating nickel smelting slag is an efficient and environmentally friendly metallurgical technology. Through gas-solid reaction and staged distillation and decomposition, carbonyl nickel and carbonyl iron products can be produced respectively, thus preparing high-quality nickel products and realizing the resource utilization of iron. Summary of the invention

[0005] The purpose of the present invention is to provide a method for comprehensively recycling nickel smelting slag from carbonyl metallurgy to extract iron and nickel. The method can not only utilize the stockpiled nickel smelting slag to extract high-purity carbonyl nickel powder, but also achieve the high-value application of iron and enrich copper in the slag. The process is simple and environmentally friendly.

[0006] The present invention adopts the following technical scheme: A method for extracting iron and nickel from nickel smelting slag by comprehensive recycling of nickel smelting slag by carbonylation metallurgy, characterized in that it specifically comprises the following steps: 1) The nickel smelting slag is reduced to obtain a metal alloy; a medium frequency furnace or a side-blown furnace is used for reduction with hydrogen, and the reduction temperature is controlled at 300-700°C. The nickel smelting slag contains 0.2-0.4% nickel and 0.2-0.5% copper.

[0007] 2) The metal alloy is subjected to powdering treatment, using vacuum gas atomization to make powder, with a melting temperature of 1500-1600° C. and a nozzle pressure of 3-5 MPa, so as to obtain metal alloy powder, and the particle size of the metal alloy powder is controlled to be 30-100 μm.

[0008] 3) The metal alloy powder is subjected to ore dressing treatment to obtain metal alloy concentrate and tailings; wherein the metal alloy concentrate accounts for 6%-10%, contains 15-25% nickel, and contains 30-60% iron.

[0009] 4) Activating the metal alloy concentrate to obtain activated metal alloy powder; using N2S and SO2 gas for activation, with a gas flow rate of 27 Nm 3 / h, activation time 0.5~2.5h.

[0010] 5) reacting the activated metal alloy powder with carbon monoxide in a pressure autoclave to obtain a mixture of carbonyl nickel, carbonyl iron and carbon monoxide and a carbonyl tailing; the pressure in the pressure autoclave is controlled at 3-10 MPa, the temperature is controlled at 120° C.-400° C., the CO gas flow rate is controlled at 1-4 m / s, and the reaction time is 12-36 h; (the carbonyl product accounts for 2-6% of the mixed gas, the nickel grade of the carbonyl tailing is 3%-8%, and the iron grade is 19%-23%).

[0011] 6) subjecting the mixture of carbonyl nickel, carbonyl iron and carbon monoxide to subsequent condensation-distillation-decomposition treatment to obtain carbonyl nickel powder, carbonyl iron powder and carbon monoxide; the condensation temperature is 0-5°C; the distillation temperature is 45-51.6°C at the top of the tower, 52.6-55°C at the bottom of the tower, and the pressure of the bottom of the distillation tower is 0.05-0.07MPa; the decomposer temperature is 500-650°C and the pressure is 0.1MPa.

[0012] Compared with the prior art, the present invention has the following beneficial effects: The carbonylation process has a very high degree of selectivity for separation of metals. The present invention combines raw material pretreatment with the carbonylation process and activates it with a catalytic gas to improve reaction activity and reaction efficiency. That is, high-purity carbonyl nickel powder can be extracted from stored nickel smelting slag, and high-value application of iron can be achieved. In addition, copper can be enriched in the slag. The process is simple and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0014] The present invention is further explained below with reference to specific embodiments.

[0015] Example 1 Ginseng Figure 1 A method for extracting iron and nickel from nickel smelting slag by comprehensive recycling of nickel smelting slag by carbonylation metallurgy, wherein the key steps of the treatment process include: 1) The nickel smelting slag is reduced by using a medium frequency furnace, and the reduction temperature is set to 330°C; 2) Powdering the metal alloy to obtain metal alloy powder, using vacuum gas atomization, melting temperature of 1500° C., nozzle pressure of 3 MPa, and powder particle size range of 50-100 μm; 3) treating the metal alloy powder through a mineral processing process to obtain metal alloy concentrate and tailings; the concentrate accounts for 6%, contains 17% nickel and 37% iron; 4) Activating the metal alloy concentrate to obtain activated metal alloy powder; using N2S gas for activation at a gas flow rate of 27 Nm 3 / h; 5) reacting the activated metal alloy powder with carbon monoxide in a pressurized vessel, with a pressure of 3 MPa, a temperature of 150° C., a CO gas flow rate of 3.3 m / s, and a reaction time of 24 h to obtain a mixture of carbonyl nickel, carbonyl iron and carbon monoxide and a carbonyl tailing; the carbonyl product accounts for 2.5% of the mixed gas, and the nickel grade of the carbonyl tailing is 3%, and the iron grade is 19%; 6) The mixture of carbonyl nickel, carbonyl iron and carbon monoxide is subjected to subsequent condensation-distillation-decomposition treatment to obtain carbonyl nickel powder, carbonyl iron powder and carbon monoxide. The condensation temperature is 5°C; the distillation temperature is 45°C at the top of the tower, 53°C at the bottom of the tower, and the pressure of the bottom of the distillation tower is 0.05MPa; the decomposer temperature is 500°C and the pressure is 0.1MPa.

[0016] Example 2 Ginseng Figure 1 A method for extracting iron and nickel from nickel smelting slag by comprehensive recycling of nickel smelting slag by carbonylation metallurgy, wherein the key steps of the treatment process include: 1) The nickel smelting slag is reduced by using a medium frequency furnace, and the reduction temperature is set to 450°C; 2) Powdering the metal alloy to obtain metal alloy powder, using vacuum gas atomization for powdering, with a melting temperature of 1550° C., a nozzle pressure of 5 MPa, and a powder particle size range of 50-100 μm; 3) treating the metal alloy powder through a mineral processing process to obtain metal alloy concentrate and tailings; the concentrate accounts for 7.5%, contains 21% nickel and 32% iron; 4) Activating the metal alloy concentrate to obtain activated metal alloy powder; using N2S gas for activation at a gas flow rate of 27 Nm 3 / h; 5) reacting the activated metal alloy powder with carbon monoxide in a pressurized vessel, with a pressure of 8 MPa, a temperature of 180° C., a CO gas flow rate of 2.4 m / s, and a reaction time of 12 h to obtain a mixture of carbonyl nickel, carbonyl iron, and carbon monoxide and a carbonyl tailing; the carbonyl product accounts for 4.5% of the mixed gas, and the nickel grade of the carbonyl tailing is 5%, and the iron grade is 22%; 6) The mixture of carbonyl nickel, carbonyl iron and carbon monoxide is subjected to subsequent condensation-distillation-decomposition treatment to obtain carbonyl nickel powder, carbonyl iron powder and carbon monoxide. The condensation temperature is 5°C; the distillation temperature is 49°C at the top of the tower, 54.6°C at the bottom of the tower, and the pressure of the bottom of the distillation tower is 0.05MPa; the decomposer temperature is 550°C and the pressure is 0.1MPa.

[0017] Example 3 Ginseng Figure 1 A method for extracting iron and nickel from nickel smelting slag by comprehensive recycling of nickel smelting slag by carbonylation metallurgy, wherein the key steps of the treatment process include: 1) The nickel smelting slag is reduced by using a side-blown furnace, and the reduction temperature is set to 660°C; 2) Powdering the metal alloy to obtain metal alloy powder, using vacuum gas atomization, a melting temperature of 1600° C., a nozzle pressure of 4 MPa, and a powder particle size range of 30-100 μm; 3) treating the metal alloy powder through a mineral processing process to obtain metal alloy concentrate and tailings; the concentrate accounts for 25%, contains 25% nickel and 56% iron; 4) Activating the metal alloy concentrate to obtain activated metal alloy powder; using SO2 gas for activation at a gas flow rate of 27 Nm 3 / h; 5) reacting the activated metal alloy powder with carbon monoxide in a pressurized vessel, with a pressure of 10 MPa, a temperature of 250° C., a CO gas flow rate of 3.4 m / s, and a reaction time of 12 h to obtain a mixture of carbonyl nickel, carbonyl iron and carbon monoxide and a carbonyl tailing; the carbonyl product accounts for 5.6% of the mixed gas, and the nickel grade of the carbonyl tailing is 8%, and the iron grade is 23%; 6) The mixture of carbonyl nickel, carbonyl iron and carbon monoxide is subjected to subsequent condensation-rectification-decomposition treatment to obtain carbonyl nickel powder, carbonyl iron powder and carbon monoxide. The condensation temperature is 0°C; the distillation temperature is 51°C at the top of the tower, 55°C at the bottom of the tower, and the pressure of the bottom of the distillation tower is 0.05MPa; the decomposer temperature is 650°C and the pressure is 0.1MPa.

[0018] The carbonylation yields of nickel in the above examples 1-3 are shown in Table 1 below: Table 1 Ni carbonylation yield

Claims

1. A method for extracting iron and nickel by comprehensive recycling of nickel smelting slag by carbonylation metallurgy, characterized in that: The specific steps include: 1) Reducing the nickel smelting slag to obtain a metal alloy; using a medium frequency furnace or a side-blown furnace, using hydrogen for reduction, the reduction temperature is controlled at 300-700°C, the nickel smelting slag contains 0.2-0.4% nickel and 0.2-0.5% copper; 2) Powdering the metal alloy by vacuum gas atomization, melting temperature of 1500-1600° C., nozzle pressure of 3-5 MPa, so as to obtain metal alloy powder, wherein the particle size of the metal alloy powder is controlled to be 30-100 μm; 3) treating the metal alloy powder by beneficiation to obtain metal alloy concentrate and tailings; wherein the metal alloy concentrate accounts for 6%-10%, contains 15-25% nickel, and contains 30-60% iron; 4) Activating the metal alloy concentrate to obtain activated metal alloy powder; using N2S or SO2 gas for activation, with a gas flow rate of 27 Nm 3 / h, activation time 0.5~2.5h; 5) reacting the activated metal alloy powder with carbon monoxide in a pressure autoclave to obtain a mixture of carbonyl nickel, carbonyl iron and carbon monoxide and carbonyl tailings; the pressure in the pressure autoclave is controlled at 3-10 MPa, the temperature is controlled at 120° C.-400° C., the CO gas flow rate is controlled at 1-4 m / s, and the reaction time is 12-36 h; 6) subjecting the mixture of carbonyl nickel, carbonyl iron and carbon monoxide to subsequent condensation-distillation-decomposition treatment to obtain carbonyl nickel powder, carbonyl iron powder and carbon monoxide; the condensation temperature is 0-5° C.; the distillation temperature is 45-51.6° C. at the top of the tower, 52.6-55° C. at the bottom of the tower, and the pressure of the bottom of the distillation tower is 0.05-0.07 MPa; The decomposer temperature is 500-650℃ and the pressure is 0.1MPa.

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