A method and device for producing high-quality nickel matte from low-quality nickel matte

Abstract

The present invention relates to the field of nickel smelting technology, and discloses a method and device for producing high-grade nickel matte from low-grade nickel matte. The method comprises: continuously introducing solid low-grade nickel matte and silicon dioxide into an oxygen-enriched blowing furnace for blowing to produce high-grade nickel matte, blowing slag, and blowing flue gas; and spraying a reducing agent, a sulfiding agent, and oxygen-enriched air II into a slag oxygen-enriched and depleted molten pool reaction zone to carry out a reduction and sulfidation reaction with the blowing slag to produce high-cobalt low-grade nickel matte and depleted slag. The process for producing high-grade nickel matte from low-grade nickel matte provided by the present invention has the advantages of high nickel and cobalt recovery rate, stable flue gas composition and volume, and environmental friendliness.

Description

Technical Field

[0001] The present invention relates to the field of nickel smelting technology, and in particular to a method and device for producing high-grade nickel matte from low-grade nickel matte. Background Art

[0002] Nickel ores mainly include nickel sulfide ore and nickel oxide ore.

[0003] The nickel smelting processes mainly include pyrometallurgical process and hydrometallurgical process.

[0004] For nickel sulfide ore, a pyrometallurgical process is generally used. The nickel sulfide ore is oxidized and smelted to produce low-grade nickel matte, which is then blown to produce high-grade nickel matte.

[0005] For nickel oxide ore, there are mainly wet leaching process and pyrometallurgical smelting process. The intermediate products of the pyrometallurgical process are divided into nickel-iron alloy and low-grade nickel matte.

[0006] The low-grade nickel matte intermediates produced by sulfide ores and oxide ores need to be further refined to produce high-grade nickel matte.

[0007] Currently, low-grade nickel matte converting is performed using the traditional converter converting process. The main drawbacks of this process include: harsh operating environments, intermittent operations, large fluctuations in sulfur dioxide concentration in the flue gas, poor performance in the subsequent acid production process, the need for hot smelted material for converting, and the difficulty of converting cold material alone. The converting furnace lining, especially the tuyere bricks, has a short lifespan, and the nickel and cobalt recovery rate is low. Summary of the Invention

[0008] The purpose of the present invention is to overcome the above-mentioned defects in the low-matte nickel blowing process in the prior art and to provide a process for producing high-matte nickel from low-matte nickel with a high nickel and cobalt recovery rate.

[0009] In order to achieve the above object, a first aspect of the present invention provides a method for producing high-grade nickel matte from low-grade nickel matte, the method comprising:

[0010] (1) Low-grade nickel matte blowing

[0011] Solid low-grade nickel matte and flux I are continuously introduced into an oxygen-enriched blowing furnace for blowing to produce high-grade nickel matte, blowing slag, and blowing flue gas;

[0012] (2) Oxygen enrichment and depletion of blowing slag

[0013] The reducing agent, sulfiding agent and oxygen-enriched air II are sprayed into the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace, and the blowing slag is intermittently drawn out from the oxygen-enriched blowing furnace to flow into the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace through a slag chute to carry out reduction and sulfidation reaction to produce high-cobalt low-nickel matte and depleted slag; the oxygen excess coefficient α of the oxygen-enriched air II to the reducing agent is controlled to be 0.4-0.5; the temperature in the slag depletion furnace is controlled to be 1250-1400℃; the high-cobalt low-nickel matte is returned to the oxygen-enriched blowing furnace for blowing.

[0014] A second aspect of the present invention provides a device for producing high-grade nickel matte from low-grade nickel matte, the device comprising:

[0015] Oxygen-enriched converting furnace;

[0016] slag depletion furnace;

[0017] Slag chute, connecting the oxygen-enriched converting furnace and the slag depletion furnace;

[0018] The oxygen-enriched converting furnace and the slag depletion furnace both include a vertical fixed furnace body;

[0019] The vertical fixed furnace body includes a gas phase furnace body, a furnace top cover, a molten pool reaction zone furnace body formed by a water-cooling structure, and a furnace hearth built of refractory materials;

[0020] The furnace is provided with a slag discharge port and a siphon channel. The shell of the furnace is composed of a steel frame, a pull rod and a spring component. The spring component is located between the steel frame and the pull rod. The shell of the furnace is an elastic structure.

[0021] The process for producing high-grade nickel matte from low-grade nickel matte provided by the present invention has the advantages of high nickel and cobalt recovery rate, stable flue gas composition and flue gas volume, and environmental friendliness.

[0022] Moreover, the SO2 concentration in the flue gas obtained by the process of producing high-grade nickel matte from low-grade nickel matte of the present invention is high, which is beneficial to acid production; further, the acid production process can operate independently from the cold material of the smelting system, so that the furnace body operation cycle of the device of producing high-grade nickel matte from low-grade nickel matte of the present invention is long. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a process flow chart of producing high-grade nickel matte from low-grade nickel matte of the present invention;

[0024] Figure 2 1. The diagram shows a front view and a side view of an oxygen-enriched blowing furnace in a device for producing high-grade nickel matte from low-grade nickel matte according to the present invention;

[0025] Figure 3 It is a schematic diagram of the connection of the device for producing high-grade nickel matte from low-grade nickel matte according to the present invention.

[0026] Description of Reference Numerals

[0027] a. Oxygen-enriched converting furnace; b. Slag chute; c. Slag depletion furnace

[0028] 1. Hearth; 2. Flat water jacket; 3. First layer water cooling element; 4. Second layer water cooling element; 5. Refractory masonry; 6. Water cooling jacket; 7. Smoke exhaust duct; 8. Flue water jacket; 9. Charging port; 10. Furnace top cover; 11. Tertiary air inlet; 12. Secondary air inlet; 13. Slag outlet; 14. Primary air inlet; 15. Matte nickel outlet; 16. Steel frame; 17. Tie rod DETAILED DESCRIPTION

[0029] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0030] As mentioned above, the first aspect of the present invention provides a method for producing high-grade nickel matte from low-grade nickel matte, the method comprising:

[0031] (1) Low-grade nickel matte blowing

[0032] Solid low-grade nickel matte and flux I are continuously introduced into an oxygen-enriched blowing furnace for blowing to produce high-grade nickel matte, blowing slag, and blowing flue gas;

[0033] (2) Oxygen enrichment and depletion of blowing slag

[0034] The reducing agent, sulfiding agent and oxygen-enriched air II are sprayed into the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace, and the blowing slag is intermittently drawn out from the oxygen-enriched blowing furnace to flow into the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace through a slag chute to carry out reduction and sulfidation reaction to produce high-cobalt low-nickel matte and depleted slag; the oxygen excess coefficient α of the oxygen-enriched air II to the reducing agent is controlled to be 0.4-0.5; the temperature in the slag depletion furnace is controlled to be 1250-1400℃; the high-cobalt low-nickel matte is returned to the oxygen-enriched blowing furnace for blowing.

[0035] In the present invention, the oxygen excess coefficient α of the oxygen-enriched air II to the reducing agent = the actual molar amount of oxygen provided / the theoretical molar amount of oxygen required for complete reaction of the system.

[0036] Preferably, in step (1), the solid low-grade nickel matte contains 20wt%-25wt% of nickel element, 45wt%-55wt% of iron element, 0.5wt%-1.5wt% of cobalt element, and 20wt%-35wt% of sulfur element.

[0037] Preferably, in step (1), the blowing slag flows into the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace through a slag chute; the flux I is silicon dioxide; the conditions in the oxygen-enriched blowing furnace and the weight ratio of the solid low-grade nickel matte and the flux I are controlled so that the mass ratio of iron element to silicon dioxide in the blowing slag is 1.5-2.5:1.

[0038] According to a preferred embodiment, in step (1), the method further comprises: injecting oxygen-enriched air I into the oxygen-enriched blowing furnace.

[0039] Preferably, in step (1), the volume concentration of oxygen in the oxygen-enriched air I is 40% to 70%, and the pressure of the injected oxygen-enriched air I is 0.08 MPa to 0.2 MPa.

[0040] Preferably, in step (1), the method further comprises: injecting pulverized coal into the primary air inlet in the oxygen-enriched blowing furnace, wherein the injection amount of pulverized coal is 1 wt% to 3 wt% of the amount of material entering the furnace, and the amount of material entering the furnace is the sum of the amounts of solid low-grade nickel matte and flux I.

[0041] The present invention has no special requirements on the particle size and source of the pulverized coal. Those skilled in the art can use pulverized coal known in the art to implement the solution of the present invention.

[0042] Preferably, in step (1), the blowing temperature in the oxygen-enriched blowing furnace is 1250-1350°C.

[0043] Preferably, in step (1), the method further comprises: passing the blowing flue gas through a waste heat boiler to recover waste heat, an electrostatic precipitator to remove dust, and then introducing the gas into a flue gas acid-making system for post-treatment.

[0044] Preferably, in step (2), the method further comprises: introducing flux II into the slag oxygen-enriched molten pool reaction zone of the slag depletion furnace; flux II is limestone.

[0045] Preferably, in step (2), the method further comprises: introducing flux II into the slag oxygen-enriched molten pool reaction zone of the slag depletion furnace; flux II is calcium oxide and / or calcium carbonate.

[0046] Preferably, in step (2), the method further comprises: introducing flux II into the slag oxygen-enriched depleted molten pool reaction zone of the slag depletion furnace; flux II is calcium oxide and / or calcium carbonate; and the amount of flux II introduced is such that the weight ratio of CaO / SiO2 of the slag in the slag depletion furnace is 0.3-0.6:1.

[0047] Preferably, in step (2), the reducing agent is selected from at least one of coke powder, bituminous coal and anthracite; the amount of the reducing agent with a particle size of 200 mesh or more is more than 80wt%; and the weight ratio of the blowing slag to the reducing agent is 100:5-15.

[0048] Preferably, in step (2), the sulfiding agent is sulfur, and the amount of sulfur with a particle size of 200 mesh or more in the sulfiding agent is more than 80wt%; the weight ratio of the blowing slag to the sulfiding agent is 100:3-5.

[0049] Preferably, in step (2), the volume concentration of oxygen in the oxygen-enriched air II is 60% to 80%, and the pressure of the injected oxygen-enriched air II is 0.2 MPa to 0.4 MPa.

[0050] According to a preferred specific embodiment, in step (2), the reducing agent is sprayed into the slag oxygen-enriched and depleted molten pool reaction zone by compressed air at a pressure of 0.6Mpa to 0.8Mpa, and the sulfiding agent is sprayed into the slag oxygen-enriched and depleted molten pool reaction zone by nitrogen at a pressure of 0.6Mpa to 0.8Mpa.

[0051] Preferably, in step (2), the conditions of the reduction sulfidation reaction are controlled so that the metallization rate Me of high cobalt and low nickel matte is 形式 is 0.20~0.4; among them, Me 形式 =(S 理论 -S 实际 ) / S 理论 , S 理论 is the theoretical mass content of sulfur in high-cobalt low-grade nickel matte, S 实际 It is the actual mass content of sulfur element in high-cobalt low-grade nickel matte. The theoretical mass content of sulfur element in high-cobalt low-grade nickel matte is the theoretical sulfur content when the iron, nickel and cobalt elements in high-cobalt low-grade nickel matte are completely sulfided.

[0052] Preferably, in step (2), the time for the blowing slag to participate in the reduction sulfidation reaction in the slag depletion furnace is 1.5-2.0 hours, the slag discharge time of the blowing slag is 2-3 hours, and the slag discharge time interval of the depleted slag is 2-3 hours.

[0053] In the present invention, the interval of slag discharge of high cobalt and low nickel matte is determined according to the amount of slag.

[0054] The following combination Figure 1 A preferred embodiment of the method for producing high-grade nickel matte from low-grade nickel matte of the present invention is described, and the method comprises:

[0055] (1) Solid low-grade nickel matte (i.e. Figure 1 "Low nickel matte" shown in Figure 1 The "silicon dioxide" shown in the figure) is continuously introduced into the oxygen-enriched blowing furnace for blowing after being batched by a metering belt. Oxygen-enriched air I is sprayed into the molten pool of the oxygen-enriched blowing furnace through the primary air port of the furnace body in the molten pool reaction zone, and pulverized coal (i.e., Figure 1) and simultaneously introduce secondary air into the oxygen-enriched blowing furnace to produce high-grade nickel matte, blowing slag and blowing flue gas; quench the intermittently discharged high-grade nickel matte with water; discharge the blowing slag from the end slag outlet every 2-3 hours and flow into the slag depletion furnace in step (2) through the slag chute; the blowing flue gas is sequentially passed through the waste heat boiler to recover waste heat, and the electrostatic precipitator for dust removal, and then introduced into the flue gas acid system for post-treatment;

[0056] The conditions are controlled so that the mass ratio of iron to silicon dioxide in the blowing slag is 1.5-2.5:1; the volume concentration of oxygen in the oxygen-enriched air I is 40% to 70%; the pressure of the injected oxygen-enriched air I is 0.08 MPa to 0.2 MPa; the amount of pulverized coal injected is 1 wt% to 3 wt% of the amount of material fed into the furnace; and the blowing temperature in the oxygen-enriched blowing furnace is 1250 to 1350° C.

[0057] (2) Flux II ( Figure 1 Specifically shown as "limestone"), reducing agent, sulfiding agent, oxygen-enriched air II, and blowing slag are sprayed into the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace to carry out reduction and sulfidation reaction. At the same time, secondary oxygen-enriched gas is introduced into the slag oxygen-enriched and depleted molten pool reaction zone to control the conditions of the reduction and sulfidation reaction so that the metallization rate Me of high cobalt and low nickel matte is 形式 The ratio is 0.20 to 0.4, producing high cobalt and low nickel matte, depleted slag, and high-temperature flue gas. The reducing agent is injected through compressed air, and the sulfiding agent is injected through nitrogen.

[0058] The oxygen excess coefficient α of the oxygen-enriched air II to the reducing agent is controlled to be 0.4-0.5; the temperature in the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace is controlled to be 1250-1400°C; the pressure of the compressed air is 0.6 MPa-0.8 MPa; the pressure of the nitrogen is 0.6 MPa-0.8 MPa; the amount of flux II introduced is such that the weight ratio of CaO / SiO2 in the slag in the slag depletion furnace is 0.3:1 to 0.6:1; the weight ratio of the blowing slag to the reducing agent is 100:5-15; the weight ratio of the blowing slag to the sulfiding agent is 100:3-5; the volume concentration of oxygen in the oxygen-enriched air II is 60%-80%, and the pressure of the oxygen-enriched air II is 0.2 MPa-0.4 MPa.

[0059] The low-grade nickel matte of the present invention is blown and oxidized in an oxygen-enriched blowing furnace to produce high-grade nickel matte and blowing slag. The blowing slag enters a slag depletion furnace for reduction and sulfidation, and the obtained low-grade nickel matte can be returned to the oxygen-enriched blowing furnace for further blowing. In step (1), the nickel sulfide and iron sulfide need to be converted into nickel oxide, iron oxide and sulfur dioxide in the oxygen-enriched blowing furnace, and impurities such as iron and sulfur are removed by oxidation, so more oxygen is needed, and a flux needs to be added to separate impurities such as iron oxide in the melt. In step (2), the slag depletion furnace needs to reduce and sulfidate the nickel oxide in the blowing slag into nickel sulfide for enrichment. If the oxygen content is too high, the reduction is insufficient, resulting in poor nickel enrichment effect. In order to obtain a higher nickel yield, the present invention controls the degree of redox by respectively controlling the different oxygen concentrations and pressures, temperatures, proportions of other raw materials, feeding methods, etc. of the oxygen-enriched air sprayed into the oxygen-enriched blowing furnace and the slag depletion furnace.

[0060] As mentioned above, the second aspect of the present invention provides a device for producing high-grade nickel matte from low-grade nickel matte, the device comprising:

[0061] Oxygen-enriched converting furnace;

[0062] slag depletion furnace;

[0063] Slag chute, connecting the oxygen-enriched converting furnace and the slag depletion furnace;

[0064] The oxygen-enriched converting furnace and the slag depletion furnace both include a vertical fixed furnace body;

[0065] The vertical fixed furnace body includes a gas phase furnace body, a furnace top cover, a molten pool reaction zone furnace body formed by a water-cooling structure, and a furnace hearth built of refractory materials;

[0066] The furnace is provided with a slag discharge port and a siphon channel. The shell of the furnace is composed of a steel frame, a pull rod and a spring component. The spring component is located between the steel frame and the pull rod. The shell of the furnace is an elastic structure.

[0067] Preferably, the vertical fixed furnace body further includes a flue.

[0068] Preferably, in the furnace body of the molten pool reaction zone, the water cooling structure is composed of multiple layers of water cooling parts, and the water cooling parts are copper water jackets or steel water jackets; the water cooling part located at the bottom of the furnace body is a single-layer water cooling part, and the upper part of the single-layer water cooling part is a double-layer water cooling part, wherein the single-layer water cooling part is provided with no less than two primary air vents; the vent angle is -5 degrees to 5 degrees in the horizontal direction;

[0069] The primary air inlet of the oxygen-enriched blowing furnace is used to inject oxygen-enriched air I, and the primary air inlet of the slag depletion furnace is used to inject oxygen-enriched air II, reducing agent and sulfiding agent; the feeding hole of the slag depletion furnace is used to add flux II.

[0070] Preferably, the furnace body in the gas phase zone is formed by alternating refractory masonry and water-cooling jacket structures, and the thickness of the refractory masonry between the water-cooling jacket structures is independently 200 mm to 400 mm.

[0071] Preferably, the furnace top cover adopts a water-cooling structure, which is composed of multiple layers of water-cooling parts. The water-cooling parts are copper water jackets or steel water jackets. The furnace top cover is provided with no less than one feeding hole.

[0072] Preferably, a slag outlet is provided at one end of the furnace body in the molten pool reaction zone above the tuyere.

[0073] Preferably, the water jackets of the molten pool reaction zones of the oxygen-enriched converting furnace and the slag depletion furnace are connected to the steel frame via tie rods.

[0074] The following combination Figure 2 and Figure 3 A preferred embodiment of the device for producing high-grade nickel matte from low-grade nickel matte of the present invention is described. The device comprises:

[0075] Oxygen-enriched converting furnace a;

[0076] slag depletion furnace c;

[0077] Slag chute b, connecting the oxygen-enriched blowing furnace a and the slag depletion furnace c;

[0078] The oxygen-enriched converting furnace a and the slag depletion furnace c both include a vertical fixed furnace body;

[0079] The vertical fixed furnace body includes a gas phase furnace body, a furnace top cover 10, a molten pool reaction zone furnace body formed by a water-cooling structure, and a furnace hearth 1 built of refractory materials;

[0080] The furnace 1 is provided with a slag discharge port 13 and a siphon channel. The shell of the furnace 1 is composed of a steel frame 16, a pull rod 17 and a spring component. The spring component is located between the steel frame and the pull rod. The shell of the furnace is an elastic structure.

[0081] Preferably, a nickel matte discharge port 15 is provided on the furnace cylinder 1 to discharge high-cobalt low-nickel matte.

[0082] Preferably, a flat water jacket 2 is provided on the upper surface of the furnace cylinder 1 .

[0083] Preferably, in the furnace body of the molten pool reaction zone, the water-cooling structure is composed of a plurality of layers of water-cooling parts, and the water-cooling parts are copper water jackets or steel water jackets; the water-cooling parts located at the bottom of the furnace body are a first-layer water-cooling part 3, and the upper part of the first-layer water-cooling part 3 is a second-layer water-cooling part 4, wherein the first-layer water-cooling part 3 is provided with no less than two primary air inlets 14; the angle of the primary air inlet is -5 degrees to 5 degrees in the horizontal direction.

[0084] Preferably, the second layer of water cooling element 4 is provided with no less than two secondary air inlets 12 .

[0085] Preferably, the angle of each secondary air outlet is independently 0° to 30° downward along the horizontal direction.

[0086] Preferably, the cross-sectional area ratio of the primary tuyere of the oxygen-enriched blowing furnace a to the primary tuyere of the slag depletion furnace c is 1.1-1.25:1.

[0087] Preferably, the oxygen-enriched converting furnace is arranged higher than the slag depletion furnace.

[0088] Preferably, the furnace body in the gas phase zone is formed by alternating refractory masonry 5 and water-cooling jacket 6 structures, and the thickness of the refractory masonry between the water-cooling jacket structures is independently 200 mm to 400 mm.

[0089] Preferably, tertiary tuyere 11 is provided on both sides of the furnace body in the gas phase zone for injecting air or oxygen-enriched air into the furnace, and the angle of each tertiary tuyere is independently 0° to 30° downward in the horizontal direction.

[0090] Preferably, the furnace top cover 10 is provided with a smoke exhaust duct 7 and a flue water jacket 8 .

[0091] Preferably, the furnace top cover 10 adopts a water-cooling structure, which is composed of multiple layers of water-cooling parts. The water-cooling parts are copper water jackets or steel water jackets. The furnace top cover 10 is provided with at least one feeding hole 9.

[0092] Preferably, the water jackets of the molten pool reaction zones of the oxygen-enriched converting furnace and the slag depletion furnace are connected to the steel frame 16 via tie rods 17 .

[0093] Preferably, a slag outlet 13 is provided at one end of the furnace body in the molten pool reaction zone above the tuyere.

[0094] The solution provided by the present invention has the characteristics of short process flow, low energy consumption, good environmental protection effect, and high degree of automation. Specifically, the present invention has the following advantages:

[0095] (1) The present invention adopts continuous feeding, continuous oxygen-enriched blowing, and a slightly excessive amount of sulfiding agent, so that the sulfur dioxide concentration in the flue gas is high and stable, which is beneficial to flue gas acid production and solves the current problems of large fluctuations in sulfur dioxide concentration in flue gas from low-grade nickel matte converter blowing and low-altitude pollution;

[0096] (2) The present invention adopts cold material blowing, and the blowing system can be separated from the smelting and operated independently, which solves the problem that the current converter hot material blowing must be configured together with the smelting, and the blowing is difficult to operate with cold material alone;

[0097] (3) The dedicated blowing and slag depletion device used in the present invention reduces the temperature, and the water-cooling structure of the copper or steel jacket is adopted in the tuyere area, which prolongs the life of the furnace body and solves the problem that the refractory masonry of the converter blowing furnace body, especially the refractory masonry in the tuyere area, has a short service life due to excessive temperature.

[0098] (4) The present invention uses hot blown slag to flow into a slag depletion furnace through a slag chute, and performs a reduction and sulfidation reaction in the slag depletion furnace, so that nickel and cobalt are fully recovered, and high-cobalt low-matte nickel can be produced. The low-matte nickel obtained by reduction enrichment solves the problem of low nickel and cobalt recovery rate;

[0099] (5) The oxygen-enriched blowing furnace of the present invention has three air inlets, which increases the amount of oxygen introduced, and by controlling the ratio of raw materials, the separation effect of slag and high-grade nickel matte is better, thereby improving the purity of high-grade nickel matte.

[0100] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, the raw materials used are all common commercially available products.

[0101] Unless otherwise specified, the following examples all use Figure 1 The process flow shown is carried out.

[0102] The composition of solid low-grade nickel matte is, in terms of elements, 22.5 wt% nickel, 49.09 wt% Fe, 0.81 wt% cobalt, and 27.6 wt% sulfur.

[0103] The following nickel recovery rate = [(the sum of the mass of nickel elements in the product high-cobalt nickel matte and the product high-cobalt low-cobalt nickel matte) / the mass of nickel elements in the raw material solid low-cobalt nickel matte] × 100%;

[0104] The following cobalt recovery rate = [(the sum of the mass of the cobalt element in the product high-cobalt nickel matte and the product high-cobalt low-cobalt nickel matte) / the mass of the cobalt element in the raw material low-cobalt nickel matte] × 100%.

[0105] Example 1

[0106] (1) solid low-grade nickel matte and silicon dioxide are fed through a metering belt and continuously introduced into an oxygen-enriched blowing furnace through a feeding hole for blowing, oxygen-enriched air I is sprayed into the molten pool of the oxygen-enriched blowing furnace through a primary air port of the furnace body in the molten pool reaction zone, and pulverized coal is sprayed into a primary air port in the oxygen-enriched blowing furnace to produce high-grade nickel matte, blowing slag and blowing flue gas; the high-grade nickel matte is intermittently discharged for water quenching; the blowing slag is discharged from the end slag discharge port every 2 hours and flows into the slag depletion furnace in step (2) through a slag chute; the blowing flue gas is sequentially passed through a waste heat boiler to recover waste heat and an electrostatic precipitator for dust removal, and then introduced into a flue gas acid-making system for post-treatment;

[0107] The control conditions are such that the mass ratio of iron to silicon dioxide in the blowing slag is 2.0:1; the volume concentration of oxygen in the oxygen-enriched air I is 50%; the pressure of the oxygen-enriched air is 0.2 MPa; the injection rate of pulverized coal is 1 wt% of the charge; and the blowing temperature in the oxygen-enriched blowing furnace is 1250°C.

[0108] (2) After the blown slag flows into the slag depletion furnace through the slag chute, limestone is added through the feeding hole, and the reducing agent, sulfiding agent, and oxygen-enriched air II are sprayed into the slag-enriched oxygen-depleted molten pool reaction zone of the slag depletion furnace through the primary tuyere to carry out reduction and sulfidation reaction. The conditions of the reduction and sulfidation reaction are controlled to make the metallization rate Me of high cobalt and low nickel matte 形式 The ratio is 0.20, producing high cobalt, low nickel matte and depleted slag; the reducing agent is injected by compressed air, and the sulfiding agent is injected by nitrogen;

[0109] The oxygen excess coefficient α of oxygen-enriched air II to reducing agent is controlled to be 0.4; the temperature in the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace is controlled to be 1250°C; the pressure of compressed air is 0.6 MPa; the pressure of nitrogen is 0.6 MPa; the amount of flux II (calcium oxide) is such that the weight ratio of CaO / SiO2 in the slag in the slag depletion furnace is 0.3:1; the weight ratio of the blowing slag to the reducing agent (anthracite) is 100:5; the weight ratio of the blowing slag to the sulfiding agent (sulfur) is 100:3; the volume concentration of oxygen in the oxygen-enriched air II is 80%, and the pressure of the oxygen-enriched air II is 0.3 MPa.

[0110] The blowing flue gas is sequentially passed through the waste heat boiler to recover waste heat, the electrostatic precipitator for dust removal, and then introduced into the flue gas acid production system for post-treatment.

[0111] result:

[0112] High-grade nickel matte: In terms of the mass content of elements, Ni is 73.94%, Co is 1.82%, Fe is 1.8%, and S is 21.77%.

[0113] High cobalt low matte nickel: in terms of the mass content of elements, Ni is 20.50%, Co is 4.60%, Fe is 45.44%, and S is 28.20%.

[0114] The nickel recovery rate was 99.5% and the cobalt recovery rate was 86.3%.

[0115] Example 2

[0116] This embodiment is carried out using a process similar to that of embodiment 1, except that:

[0117] (1) The injection rate of pulverized coal is 2 wt% of the charge; the blowing temperature in the oxygen-enriched blowing furnace is 1300°C;

[0118] (2) The oxygen excess coefficient α of the oxygen-enriched air II to the reducing agent is controlled to be 0.5; the temperature in the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace is controlled to be 1300°C; the weight ratio of the blowing slag to the reducing agent (pulverized coal) is 100:10; and the weight ratio of the blowing slag to the sulfiding agent (sulfur) is 100:4.

[0119] result:

[0120] High-grade nickel matte: In terms of the mass content of elements, Ni is 74.52%, Co is 1.92%, Fe is 1.25%, and S is 21.86%.

[0121] High cobalt low matte nickel: in terms of the mass content of elements, Ni is 22.60%, Co is 4.77%, Fe is 50.35%, and S is 29.16%.

[0122] The nickel recovery rate was 99.41% and the cobalt recovery rate was 85.32%.

[0123] Example 3

[0124] This embodiment is carried out using a process similar to that of embodiment 1, except that:

[0125] (1) The injection rate of pulverized coal is 3% of the amount of material fed into the furnace;

[0126] (2) The oxygen excess coefficient α of the oxygen-enriched air II to the reducing agent is controlled to be 0.5; the weight ratio of the blowing slag to the reducing agent (pulverized coal) is 100:15; and the weight ratio of the blowing slag to the sulfiding agent (sulfur) is 100:5.

[0127] result:

[0128] High nickel matte: In terms of the mass content of elements, Ni is 75.52%, Co is 1.72%, Fe is 1.05%, and S is 22.13%.

[0129] High cobalt low matte nickel: in terms of the mass content of elements, Ni is 25.10%, Co is 5.32%, Fe is 39.92%, and S is 29.20%.

[0130] The nickel recovery rate was 99.6% and the cobalt recovery rate was 88.32%.

[0131] Example 4

[0132] This embodiment is carried out using a process similar to that of embodiment 1, except that:

[0133] (1) The conditions are controlled so that the mass ratio of iron to silicon dioxide in the blowing slag is 1.8:1; the volume concentration of oxygen in the oxygen-enriched air I is 60%; the pressure of the oxygen-enriched air is 0.2 MPa; and the blowing temperature in the oxygen-enriched blowing furnace is 1350°C;

[0134] (2) The amount of flux II (calcium oxide) introduced is such that the weight ratio of CaO / SiO2 in the slag in the slag depletion furnace is 0.4:1; the volume concentration of oxygen in the oxygen-enriched air II is 80%, and the pressure of the oxygen-enriched air II is 0.4 MPa; and the temperature in the slag oxygen-enriched molten pool reaction zone of the slag depletion furnace is controlled to be 1350°C.

[0135] High nickel matte: In terms of the mass content of elements, Ni is 74.38%, Co is 1.45%, Fe is 1.65%, and S is 21.23%.

[0136] High cobalt low matte nickel: in terms of the mass content of elements, Ni is 25.20%, Co is 6.37%, Fe is 39.62%, and S is 27.50%.

[0137] The nickel recovery rate was 99.52% and the cobalt recovery rate was 89.32%.

[0138] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A device for producing high-grade nickel matte from low-grade nickel matte, characterized in that: The device includes: Oxygen-enriched converting furnace; slag depletion furnace; a slag chute connecting the oxygen-enriched blowing furnace and the slag depletion furnace; The oxygen-enriched blowing furnace and the slag depletion furnace both include a vertical fixed furnace body; The vertical fixed furnace body includes a gas phase furnace body, a furnace top cover, a molten pool reaction zone furnace body formed by a water-cooling structure, and a furnace hearth built of refractory materials; The furnace is provided with a slag discharge port and a siphon channel. The shell of the furnace is composed of a steel frame, a pull rod and a spring component. The spring component is located between the steel frame and the pull rod. The shell of the furnace is an elastic structure. In the furnace body of the molten pool reaction zone, the water-cooling structure is composed of multiple layers of water-cooling parts, and the water-cooling part located at the bottom of the furnace body is a single layer of water-cooling parts, wherein the single layer of water-cooling parts is provided with no less than two primary air inlets; the angle of the primary air inlets is -5 degrees to 5 degrees in the horizontal direction; There are tertiary tuyere on both sides of the furnace body in the gas phase zone, which are used to inject air or oxygen-enriched air into the furnace. The angle of each tertiary tuyere is independently 0°~30° downward in the horizontal direction; The primary air inlet of the oxygen-enriched blowing furnace is used to inject oxygen-enriched air I, and the primary air inlet of the slag depletion furnace is used to inject oxygen-enriched air II, reducing agent and sulfiding agent; the feeding hole of the slag depletion furnace is used to add flux II.

2. The device according to claim 1, wherein The water-cooling component is a copper water jacket or a steel water jacket; the upper portion of the first-layer water-cooling component is a second-layer water-cooling component.

3. The device according to claim 1, wherein The gas phase zone furnace body is formed by alternating refractory masonry and water-cooling jacket structures, and the thickness of the refractory masonry between the water-cooling jacket structures is independently 200 mm to 400 mm.

4. The device according to claim 1, wherein The furnace top cover adopts a water-cooling structure, which is composed of multiple layers of water-cooling parts. The water-cooling parts are copper water jackets or steel water jackets. The furnace top cover is provided with no less than one feeding hole.

5. The device according to claim 1, wherein A slag outlet is provided at one end of the furnace body in the molten pool reaction zone, which is higher than the tuyere.

6. A method for producing high-grade nickel matte from low-grade nickel matte, characterized in that: The method is implemented in the device according to any one of claims 1 to 5, and comprises: (1) Low-grade nickel matte blowing Solid low-grade nickel matte and flux I are continuously introduced into an oxygen-enriched blowing furnace for blowing to produce high-grade nickel matte, blowing slag, and blowing flue gas; oxygen-enriched air I is sprayed into the oxygen-enriched blowing furnace, wherein the volume concentration of oxygen in the oxygen-enriched air I is 40% to 70%, and the pressure of the injected oxygen-enriched air I is 0.08 MPa to 0.2 MPa; (2) Oxygen enrichment and depletion of blowing slag The reducing agent, sulfiding agent and oxygen-enriched air II are sprayed into the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace, and the blowing slag is intermittently introduced from the oxygen-enriched blowing furnace into the slag oxygen-enriched and depleted molten pool reaction zone of the slag depletion furnace to carry out reduction and sulfidation reaction to produce high-cobalt low-nickel matte and depleted slag; the oxygen excess coefficient α of the oxygen-enriched air II to the reducing agent is controlled to be 0.4~0.5; the temperature in the slag depletion furnace is controlled to be 1250~1400℃; the high-cobalt low-nickel matte is returned to the oxygen-enriched blowing furnace for blowing; the weight ratio of the blowing slag to the reducing agent is 100:5~15, and the weight ratio of the blowing slag to the sulfiding agent is 100:3~5.

7. The method according to claim 6, wherein: In step (1), the blowing slag flows into the slag oxygen-enriched depleted molten pool reaction zone of the slag depletion furnace through a slag chute; the flux I is silicon dioxide; and the conditions in the oxygen-enriched blowing furnace are controlled so that the mass ratio of the iron element in the blowing slag to the silicon dioxide is 1.5-2.5:

1.

8. The method according to claim 6, wherein: In step (1), it also includes: spraying pulverized coal into the primary air inlet in the oxygen-enriched blowing furnace, the injection amount of the pulverized coal is 1wt%~3wt% of the amount of material entering the furnace, and the amount of material entering the furnace is the sum of the amount of the solid low-grade nickel matte and the flux I.

9. The method according to claim 6, wherein: In step (1), the blowing temperature in the oxygen-enriched blowing furnace is 1250-1350°C.

10. The method according to claim 6, wherein: In step (1), the process further includes: passing the blowing flue gas through a waste heat boiler to recover waste heat, an electrostatic precipitator to remove dust, and then introducing the gas into a flue gas acid-making system for post-processing.

11. The method according to any one of claims 6 to 10, wherein: In step (2), it also includes: adding flux II into the slag depletion furnace; the flux II is limestone.

12. The method according to any one of claims 6 to 10, wherein: In step (2), the reducing agent is selected from at least one of coke powder, bituminous coal and anthracite; and the amount of the reducing agent having a particle size of 200 mesh or more is more than 80 wt%.

13. The method according to any one of claims 6 to 10, wherein: In step (2), the sulfiding agent is sulfur, and the amount of sulfur with a particle size of 200 mesh or more in the sulfiding agent is more than 80wt%; the weight ratio of the blowing slag to the sulfiding agent is 100:3~5.

14. The method according to any one of claims 6 to 10, wherein: In step (2), the volume concentration of oxygen in the oxygen-enriched air II is 60% to 80%, and the pressure of the injected oxygen-enriched air II is 0.2 MPa to 0.4 MPa.

15. The method according to any one of claims 6 to 10, wherein: In step (2), the reducing agent is sprayed into the slag oxygen-enriched and depleted molten pool reaction zone by compressed air at a pressure of 0.6 MPa to 0.8 MPa, and the sulfiding agent is sprayed into the slag oxygen-enriched and depleted molten pool reaction zone by nitrogen at a pressure of 0.6 MPa to 0.8 MPa.

16. The method according to any one of claims 6 to 10, wherein: In step (2), the conditions of the reduction sulfidation reaction are controlled so that the metallization rate Me of the high cobalt low nickel matte is 形式 is 0.20~0.4; among them, Me 形式 =(S 理论 -S 实际 ) / S 理论 , S 理论 is the theoretical mass content of sulfur in the high-cobalt low-middle nickel matte, S 实际 It is the actual mass content of sulfur element in the high-cobalt low-grade nickel matte, and the theoretical mass content of sulfur element in the high-cobalt low-grade nickel matte is the theoretical sulfur content when the iron element, nickel element and cobalt element in the high-cobalt low-grade nickel matte are completely sulfided.

17. The method according to any one of claims 6 to 10, wherein: In step (2), the time for the blowing slag to participate in the reduction sulfidation reaction in the slag depletion furnace is 1.5-2.0 hours, the slag discharge time of the blowing slag is 2-3 hours, and the slag discharge time interval of the depleted slag is 2-3 hours.

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