WO2023077641A1 - Smelting furnace for smelting nickel matte and production method for low nickel matte - Google Patents

Abstract

A smelting furnace for smelting a nickel matte and a production method for a low nickel matte. The smelting furnace comprises: a first region (1) for melting and slagging an object to be smelted; a second region (2) for carrying out reduction and sulfidation on the object subjected to melting and slagging in the first region (1), so as to generate a target product; and a third region (3) for separating the target product, wherein the first region (1), the second region (2) and the third region (3) are communicated with each other, and a partition wall (7) is provided between the first region (1) and the second region (2) to separate the first region (1) and the second region (2); the smelting furnace comprises a first furnace body (20) and a second furnace body (30) which are independent of each other; the first furnace body (20) and the second furnace body (30) are arranged corresponding to the first region (1) and the second region (2); uptake flues for jointly discharging smoke are provided above the first region (1) and the second region (2).

Description

Smelting furnace for smelting nickel matte and production method of low nickel matte

Cross References to Related Applications

This application claims the priority of the Chinese patent application with the application number 202111293657.8 and titled "Smelting Furnace for Smelting Nickel Matte and Production Method for Low Nickel Matte" submitted to the State Intellectual Property Office of China on November 03, 2021. The entire contents are incorporated by reference in this application.

technical field

The application relates to the technical field of nickel oxide ore smelting, in particular, to a smelting furnace for smelting nickel matte and a production method for low nickel matte.

Background technique

Nickel ore resources are mainly nickel sulfide ore and nickel oxide ore. Nickel sulfide ore has a high nickel content and is easier to develop and utilize. With the reduction of nickel sulfide ore resources, the development and utilization of nickel oxide ore has become an inevitable trend. At present, the main destination of nickel oxide ore is the field of stainless steel. With the rapid growth of the global demand for nickel for battery materials, it is imperative to develop and utilize nickel oxide ore to produce intermediate products for the field of battery materials. At present, the process of processing nickel oxide ore is mainly based on pyrolysis. As a relatively mature technology, the ultra-high temperature required by the pyrotechnic temperature requires a lot of energy consumption, and the furnace requires a lot of cost and space. For example, the existing common scale Next, the production method of the converter is adopted, occupying 1 to 3 square meters can only produce 10,000 tons of nickel matte products, and every 100 to 120 furnaces need to be rebuilt, which requires a lot of cost and additional process flow for the converter. Therefore, the current research and development direction will be more and more inclined to study shorter technological processes and save costs, such as making the smelting furnace larger, or shortening the smelting furnace, reduction furnace and separation process to reduce the loss of energy consumption; for this reason, now There are technologies that provide the following directions:

A patent document discloses a device that passes through a melting pool melting furnace, a melting pool melting reduction furnace, and a chute connected to the furnace, as well as a process for reducing ferronickel from laterite nickel ore. The ferronickel produced under this process requires secondary refining, and the smelting process itself is completed by independent melting furnaces and reduction furnaces for material melting and reduction. The problem of circulation cannot adapt to continuous production, and requires the cooperation of multiple furnaces performing different functions, so the thermal efficiency of the process is not high, and the process is forced to be complicated and increase the cost.

Another patent document discloses a smelting furnace designed with a high and low hearth. There are two chambers in the smelting furnace with a height difference to solve the problem of the process flow; however, due to the process conditions of high/low nickel matte production The refining requirements of other chemical materials are quite different, and the prior art has not disclosed the process and the proprietary device associated with high/low nickel matte.

In view of this, the existing technology has not been able to realize the requirement of a smelting furnace to complete the production scale while taking into account space and cost.

Contents of the invention

The purpose of this application is to provide a smelting furnace for smelting nickel matte, which integrates the first zone, the second zone and the third zone, has short process flow, high production efficiency, high degree of automation, low device cost, and is easy to maintain. Low energy consumption.

The purpose of this application is also to provide a production method of low nickel matte, using the above-mentioned smelting furnace, the process is short, the production efficiency is high, the degree of automation is high, the device cost is low, and the energy consumption is low.

This application is implemented like this:

The present application firstly provides a melting furnace for smelting nickel matte, which includes a first area, a second area and a third area arranged in sequence in the horizontal direction, and the first area, the second area and the third area comprise a common furnace in communication The cylinder; the first area and the second area also include the first furnace body, the second furnace body and the furnace roof which are sequentially arranged on the furnace furnace from bottom to top.

Wherein, the depth difference is set between the first area and the second area, and along the direction from the first area to the second area, the bottom of the first area and the second area corresponding to the partition wall is provided with a depth gradually increasing along this direction. Gradient structure, so as to maximize the channel under the partition wall, so that slag can flow into the second area better and avoid clogging; the hearth includes a continuous shallow hearth and a deep hearth, and the bottom surface of the shallow hearth is higher than the deep hearth On the bottom surface, the shallow hearth is set corresponding to the first area, the deep hearth is set corresponding to the second area and the third area, and the low matte layer is located in the deep hearth area; the gradient structure is located at the junction of the shallow hearth and the deep hearth, Ladder or smooth slope;

The first furnace body, the second furnace body and the furnace roof are arranged corresponding to the first area and the second area, and a partition wall is provided inside the first furnace body, the second furnace body and the furnace roof to separate the first area from the second area;

The first shaft and the second shaft are respectively the lower molten pool reaction area and the upper gas phase reaction area, and the first shaft is respectively provided with a first nozzle and a second nozzle corresponding to the first area and the second area; the second shaft is in the Both the first area and the second area are equipped with secondary oxygen-enriched air nozzles;

The top of the furnace in the first area is equipped with a main feeding port, and the top of the furnace in the second area is equipped with an auxiliary feeding port;

The top of the furnace is provided with an ascending flue for exhausting smoke from the first zone and the second zone.

Specifically, the bottom of the partition wall is an arc-shaped structure with an opening downward, so as to increase the passage area under the partition wall, and facilitate the melt produced in the first area to pass into the second area; the chord height of the arc-shaped structure is preferably 100mm~ 200mm, when the chord height of the arc-shaped structure is set too high, the effect of the separation between the first area and the second area will be weakened, and the different reaction atmospheres in the two areas will easily affect each other; and when the chord height is set too low, increase the channel The effect of width is reduced.

In a preferred solution, the partition wall is a double-layer copper water jacket, and the bottom of the copper water jacket at the lowest layer of the partition wall is an arc-shaped structure.

Specifically, the hearth is made of a refractory material, and a hearth water jacket is provided on the top of the hearth to cool and protect the hearth. The hearth water jacket is preferably a copper water jacket.

Specifically, the first furnace body is spliced by multiple layers of copper water jackets, wherein the width of each single copper water jacket is 500mm-700mm, and the height is 1000mm-1400mm.

Specifically, the second furnace body is made of refractory materials and horizontal copper water jackets alternately. The distance between every two layers of horizontal copper water jackets is 200mm-400mm, and the thickness of each layer of horizontal copper water jackets is 60-80mm. The second furnace shaft is mainly made of refractory materials, which can effectively reduce the heat loss in the upper gas phase reaction area.

Specifically, the second nozzle and the first nozzle are arranged on the lowermost layer of copper water jacket of the first shaft, the height of the second nozzle is lower than that of the first nozzle, and the distance between the centerline of the first nozzle and the copper water jacket where it is located is The lower edge is 300mm-400mm, and the distance from the center line of the second nozzle to the lower edge of the copper water jacket where it is located is 200mm-300mm.

Specifically, the copper water jacket on the uppermost layer of the first furnace body expands outwards, with an inclination angle of 10°-18° relative to the vertical direction, so that the space volume of the upper gas phase reaction area can be increased, so that the reaction in the gas phase area is complete If the outward expansion angle of the uppermost layer of copper water jacket is too small, the space volume will be limited, and if it is too large, a slope with a gentle slope will be formed, and the materials cannot fall naturally, and the side walls are prone to slagging.

Specifically, according to the residence time of materials in different regions, the cross-sectional area ratio of the first region, the second region and the third region is set as (1.2-1.5):1:(0.4-0.6).

Specifically, the depth of the shallow hearth is 300mm-400mm, and the depth of the deep hearth is 600mm-1000mm.

Specifically, the roof material is a molten steel jacket.

Specifically, the first furnace body and the second furnace body are mutually independent structures. Since the refractory material has expansibility at high temperature, setting the first furnace body and the second furnace body independently can reduce the expansion of the furnace hearth at high temperature. This leads to mutual extrusion between different material structures, thereby improving the safety and service life of the entire equipment, and facilitating targeted maintenance.

Further, a load-bearing frame is provided outside the smelting furnace, and a load-bearing ring beam extending above the first furnace body is provided on the load-bearing frame. The body and the furnace roof are load-bearing.

Further, the load-bearing ring beam is provided with a load-bearing ring beam water jacket for cooling protection of the load-bearing ring beam.

Further, there is a free expansion joint with a width of 40 mm to 80 mm between the first furnace body and the load-bearing ring beam, so as to ensure that the furnace hearth can expand and contract freely at different temperatures.

Specifically, a reheating burner is provided on the top of the third area, a slag discharge port is provided on the upper side of the third area, and a low-matte discharge port is provided on the lower side of the third area.

Specifically, a tertiary tuyere may also be provided on the ascending flue to let in air or oxygen-enriched air to burn incompletely combusted carbon monoxide (CO) in the flue gas.

The present application also provides a production method of low nickel matte, using the above smelting furnace, specifically comprising the following steps:

a. Drying and crushing the nickel oxide ore until the water content is 20% to 25%, and the particle size of the nickel oxide ore after crushing is ≤50mm;

b. Add the dried and crushed nickel oxide ore, flux, and fuel to the first area of the smelting furnace according to the preset ratio, and spray oxygen-enriched air and fuel into the molten pool in the first area through the first nozzle. The lower material is rapidly melted and slagged in the stirred molten pool to form a melt;

c. The melt produced in the first area continuously flows into the second area through the lower channel of the partition wall, and the reducing agent, vulcanizing agent, and oxygen-enriched air are sprayed into the molten pool in the second area from the second nozzle, and the melt is in a strong reducing atmosphere. After reduction and vulcanization, low nickel matte and slag containing 15-30% nickel are formed;

d. The low nickel matte and slag produced in the second area flow into the third area continuously, and the low nickel matte and slag are further separated in the third area to obtain slag containing nickel ≤ 0.1%, and the low nickel matte passes through the low nickel matte outlet Discontinuous release, continuous release of slag for water quenching;

e. Spray oxygen-enriched air into the upper gas phase reaction area of the first area and the second area through the secondary oxygen-enriched air nozzle, and return the heat obtained from combustion to the molten pool;

f. The high-temperature flue gas produced in the first area and the second area passes through the ascending flue for waste heat recovery and tail gas treatment.

Specifically, the flux is lime or limestone, and the fuel is coal. The nickel oxide ore, flux, and fuel are fed according to the mass ratio of nickel oxide ore to calcium and coal of 100:(5-15):(10-20).

Specifically, the volume concentration of oxygen in the oxygen-enriched air injected into the molten pool in the first region through the first nozzle is 80-95%, the pressure of the injected oxygen-enriched air is 0.1-0.2Mpa, and the excess coefficient of oxygen-enriched air to fuel It is 0.8-0.9, and the temperature of the first zone is controlled to be 1400-1550°C.

Specifically, the reducing agent is coke powder, pulverized coal (anthracite or bituminous coal), the reducing agent is greater than 80% with a particle size of 200 mesh or more, and the mass ratio of nickel oxide ore to the amount of reducing agent added is 100: (10-15); It is at least one of sulfur and calcium sulfate, the vulcanizing agent has a particle size of more than 200 mesh and greater than 80%, and the nickel oxide ore and the vulcanizing agent are fed according to the mass ratio of nickel oxide ore and sulfur at 100:2-3.

Specifically, the volume concentration of oxygen in the oxygen-enriched air injected into the second region through the second nozzle is 80-95%, and the pressure of the oxygen-enriched air injected is 0.3-0.4Mpa.

Specifically, the temperature in the second zone is 1400°C-1550°C, the oxygen excess coefficient α is 0.3-0.4, and the oxygen excess coefficient is the consumption index of the reducing agent and the oxygen-enriched air injected into the molten pool.

Specifically, the reduction and vulcanization reaction time of the material in the second zone is 0.5-1.0 h, and the reduction and vulcanization reaction of the melt produces low-nickel matte and slag containing 15-30% nickel.

Specifically, the low nickel matte and slag produced in the second area continuously flow into the third area, and the residence time of low nickel matte and slag in the third area is ≥0.5h.

Specifically, through the secondary oxygen-enriched air nozzle, the injection angle of oxygen-enriched air is injected into the upper gas phase reaction area of the molten pool in the first area and the second area. The volume concentration is 60-80%, and the pressure of oxygen-enriched air is 0.05Mpa-0.1Mpa to burn the carbon monoxide in the gas phase reaction area and return the heat obtained from the combustion to the molten pool.

Specifically, the high-temperature flue gas enters the waste heat boiler through the ascending flue to recover waste heat to produce steam. After being cooled by the waste heat boiler, the flue gas enters the bag filter. For power generation, it can reduce dependence on external power loads.

The application has the following beneficial effects:

(1) The smelting furnace used for smelting nickel matte in this application integrates the first area, the second area and the third area, and can realize slagging and reduction sulfidation of nickel oxide ore in one furnace, as well as low nickel matte and Deep separation of slag, direct output of low nickel matte and slag, short process and high production efficiency;

(2) The first area and the second area are separated by a partition wall, which can realize the separate control of the atmosphere in different areas. Specifically, the first area can be controlled as a weak reducing atmosphere to promote full combustion of fuel, and the second area can be controlled as a strong reducing atmosphere. To promote the reduction and vulcanization of melts to produce higher-grade low-matte nickel;

(3) The degree of automation is high, and the batching system, reducing agent vulcanizing agent injection system and furnace cooling system can all be automatically controlled;

(4) The top of the furnace is equipped with an ascending flue that exhausts smoke from the first area and the second area. After the flue gas is combined, it enters a waste heat boiler to produce steam. The steam is used for power generation, reducing the dependence on external power loads. Only one set is needed. The flue gas recovery device performs heat recovery and dust removal treatment on the flue gas to realize the effect of simplifying the device and reducing the cost of the device;

(5) The melt produced in the first area directly flows into the second area, saving the heat loss during the melt transfer process, using oxygen-enriched air to strengthen the smelting, the amount of flue gas is small, the heat taken away by the flue gas is reduced, and the energy consumption is low.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is the connection topological diagram of the smelting furnace for smelting nickel matte provided by the present application;

Fig. 2 is the first cross-sectional view of the smelting furnace for smelting nickel matte shown in a specific embodiment of the present application under the main viewing angle;

Fig. 3 is the second sectional view under the side view angle of the smelting furnace in Fig. 2;

Fig. 4 is a flow chart of the production method of low matte nickel provided by the embodiment of the present application.

In the attached picture:

100. Melting furnace;

1. The first area; 2. The second area; 3. The third area; 7. The partition wall; 8. The ascending flue; 10. The hearth; 20. The first shaft; 30. The second shaft; 40. Furnace roof; 50, load-bearing frame; 11, shallow hearth; 12, deep hearth; 13, gradient structure; 14, furnace platform water jacket; 21, first nozzle; 22, second nozzle; 25, a layer of copper water jacket ; 26. Two-layer copper water jacket; 31. Secondary oxygen-enriched air nozzle; 41. Main feed port; 42. Auxiliary feed port; 51. Load-bearing ring beam; 52. Load-bearing ring beam water jacket; 61. Auxiliary burner; 62. Slag outlet; 63. Low nickel matte outlet; 81. Tertiary tuyere; 301. Refractory material; 302. Horizontal copper water jacket.

Detailed ways

In the following description of the embodiments of the present application, for the purpose of illustration rather than limitation, specific details such as the proprietary equipment applicable to the process and the process are presented for a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known connection relationships and processes in the embodiments of the present application are omitted, so as not to hinder the description of the present application with unnecessary details.

equipment:

The embodiment of the present application firstly provides a smelting furnace used in the process of nickel oxide ore, aiming to realize a smelting furnace with versatility and adaptability in the process of nickel oxide ore, and taking into account service life and mobility.

In a general inventive concept, in order to simplify the process flow, speed up industrial production, and avoid materials passing through multiple converters, the embodiment of the present application firstly provides a melting furnace 100 that can provide a continuous process. The integrated melting furnace 100 can integrate melting manufacturing Slag, reduction sulfidation and separation are integrated, so that the target product required in the industry can be obtained in a continuous process.

Referring to Fig. 1 and Fig. 2, the smelting furnace 100 includes a first area 1, a second area 2 and a third area 3 arranged in sequence (referring to an arrangement along the required process order), and the first area 1 is used for the Melting and slagging, the second zone 2 is used to reduce the smelted material after melting and slagging in the first zone 1 to produce target products, and then separate in the third zone 3 .

Specifically, the molten material to be smelted is melted and/or oxidized in the first zone 1 of the smelting furnace 100 to form a fluid melt, and then through the connection relationship between the first zone 1 and the second zone 2, the melt enters the second zone. The second area 2 is reduced to form the target product and slag, and finally flows into the third area 3; the slag and the target product are further separated in the third area 3, and they can be discharged by setting outlets respectively.

It can be understood that the term "material to be smelted" mentioned above can be nickel ore, such as laterite nickel ore, nickel oxide ore, or matte nickel raw material, and the "target product" is the process condition provided according to the embodiment of the present application Nickel matte produced from nickel ore and/or high nickel matte produced from low nickel matte.

In the embodiment of this application, in order to realize the integration of melting slagging, reduction vulcanization and separation, the smelting furnace 100 needs to be set larger in size in order to adapt to a larger production scale. Those skilled in the art should understand that this application Embodiments On the one hand, in order to meet the requirement of reducing the process flow, it is necessary to reduce the connection distance between the regions as much as possible.

Please continue to refer to Fig. 2, in order to implement the general inventive concept, in a specific embodiment, the smelting furnace 100 is stacked layer by layer, the smelting furnace 100 includes an integral hearth 10, and the first zone 1, the second Area 2 and the third area 3 are jointly built on the furnace hearth 10, designed from the vertical direction, the melting furnace 100 includes a first furnace shaft 20, a second furnace shaft 30 and Stove top 40.

Further, the first furnace body 20, the second furnace body 30 and the furnace roof 40 are arranged corresponding to the first area 1 and the second area 2, and the first furnace body 20, the second furnace body 30 and the furnace roof 40 are provided with partition walls 7 to separate the first area 1 and the second area 2, so that the first area 1 and the second area 2 form two separate cavities, and the partition wall does not completely close the cavity, leaving a certain distance from the hearth so that in A channel is formed between the partition wall 7 and the bottom of the furnace hearth 10 for flowing the melt produced in the first zone 1 into the second zone 2 .

Among them, in order to meet the requirement that the melt produced in the first area 1 can flow into the second area 2 without driving, the first area 1 and the second area 2 are provided with a depth difference, so that the melt produced in the first area 1 The melt can flow into the second zone 2 under potential energy.

Specifically, a gradient structure 13 is provided at the bottom of the hearth 10, and the gradient structure 13 can raise or lower the bottom of the hearth 10, so that the first area 1 and the second area 2 are set at different depths, that is, structurally The hearth 10 may include a shallow hearth 11 and a deep hearth 12 which communicate continuously, the shallow hearth 11 is set corresponding to the first area 1 , and the deep hearth 12 is set corresponding to the second area 2 and the third area 3 . Further, along the direction from the first region 1 to the second region 2 , that is, the depth of the gradient structure 13 gradually increases along the direction at the bottom. Specifically, the gradient structure 13 is located at the junction of the shallow hearth 11 and the deep hearth 12, and is maximized at the bottom of the corresponding partition wall 7, thereby maximizing the channel under the partition wall 7 so that the melt flows along the gradient structure 13 Flow to the second area 2 and the third area 3, so that the slag can flow into the second area 2 better and avoid clogging.

Further, the gradient structure 13 can be in the shape of steps or smooth slopes, preferably in the shape of steps. Since the slag will precipitate part of the slag when it is in a step shape, the use of a step shape versus a smooth shape can prevent some materials from concentrating on the partition wall. The underside thus narrows the channel.

In order to further solve the melt circulation problem, based on the above-mentioned specific solution, the bottom of the partition wall 7 is an arc-shaped structure with an opening downward. In this embodiment, the partition wall 7 is a double-layer copper water jacket, and the bottom of the copper water jacket at the lowest layer of the partition wall 7 is an arc-shaped structure. It can be understood that the problem of large melt production and fast speed, the combination of the arc structure and the gradient structure 13 can increase the channel area under the partition wall 7, which is conducive to the passage of the melt, and avoids the melt from clogging the channel and causing melt deposition In the first region 1 , on the other hand, stagnation and sticking of the melt can be prevented, further improving the reliability of the melting furnace 100 .

Specifically, the arc-shaped structure can increase the passage area under the partition wall 7, so that the melt produced in the first area 1 can pass into the second area 2; the chord height of the arc-shaped structure is preferably 100mm-200mm, when the arc-shaped If the chord height of the structure is set too high, the separation effect between the first area 1 and the second area 2 will be weakened, and the different reaction atmospheres in the two areas will easily interact with each other; and when the chord height is set too low, the effect of increasing the channel area will be weakened .

In a specific scheme based on the above, the material of the hearth 10 is a refractory material, and the refractory material 301 can be silica bricks and clay bricks, etc., and a water jacket 14 for cooling and protecting the hearth 10 is provided above the top edge of the hearth 10. Stovetop water jacket 14 is a copper water jacket.

In a specific solution based on the above, the second furnace body 30 is formed by alternating masonry of refractory materials 301 and horizontal copper water jackets 302. The distance between the horizontal copper water jackets 302 is 200mm-400mm, and the thickness of each horizontal copper water jacket is 60-80mm.

Among them, the refractory material 301 and the horizontal copper water jacket 302 are arranged alternately, which can block the heat transfer between the horizontal copper water jackets 302, avoid the uneven heat caused by the large-scale production and the process of concentrated heat rise, and reduce heat loss. Further enhanced reliability and heat recovery efficiency. At the same time, the horizontal copper water jacket 302 can reinforce the stability of the second shaft 30 and prevent the inner wall of the second shaft 30 from being deformed.

In a specific solution based on the above, the first furnace body 20 is spliced by multi-layer copper water jackets, wherein the width of each single piece of copper water jacket is 500mm-700mm, and the height is 1000mm-1400mm;

Optionally in this embodiment, the first furnace body 20 is spliced by two layers of copper water jackets, the second nozzle 22 and the first nozzle 21 are arranged on one layer of copper water jacket of the first furnace body 20, and the second The height of the nozzle 22 is lower than that of the first nozzle 21 , which is specifically set according to the dimensions to be designed for the first area 1 and the second area 2 .

It can be understood that after the melt is produced in the first area 1, it flows to the second area 2 through the channel on the lower side of the partition wall 7, and gradually overflows to the second nozzle 22 as the melt increases. The depth of the second region 2 is smaller than that of the second region 2, so that the melt needs to rise gradually, and the height of the second nozzle 22 is lower than the height of the first nozzle 21, so that the melt overflows to the first nozzle 21.

Specifically, the heights of the first area 1 and the second area 2 are consistent, and according to the residence time of materials in different areas, the cross-sectional area ratio of the first area 1, the second area 2 and the third area 3 is (1.2-1.5 ): 1: (0.4～0.6), it can be understood that this ratio is obtained through experiments according to the ratio of chemical reactions and related process parameters, and the simple improvements made on the ratio all belong to the scope of the embodiments of the present application within the scope of protection.

More specifically, the distance between the centerline of the first nozzle 21 and the lower edge of the copper water jacket is 300mm-400mm, and the distance between the centerline of the second nozzle 22 and the lower edge of the copper water jacket is 200mm-300mm.

In a specific solution based on the above, the two-layer copper water jacket 26 of the first shaft 20 expands outwards, and the inclination angle relative to the vertical direction is 10°-18°. To increase the space volume of the upper gas phase reaction zone, so that the reaction in the gas phase zone is complete. It can be understood that if the outward expansion angle is too small, the increased space volume will be limited, and if it is too large, a slope with a gentle slope will be formed, materials cannot fall naturally, and the side walls are prone to slagging.

In the embodiment of the present application, the bottom surface of the shallow hearth 11 is higher than the bottom surface of the deep hearth 12, and the junction between the shallow hearth 11 and the deep hearth 12 is in the shape of a step or a smooth slope, so that the exit of the passage below the partition wall 7 is maximized. and allow the slag to flow into the second area 2 better under the gradient gravity, which is conducive to the accumulation of slag and avoids clogging; the depth of the shallow hearth 11 is 300mm-400mm, and the depth of the deep hearth 12 is 600mm- 800mm.

Wherein, the furnace top 40 material is a stainless steel water jacket. The first furnace shaft 20 and the second furnace shaft 30 are mutually independent structures. It can be understood that since the refractory material has expansibility at high temperature, and the size of the first furnace body 20 and the second furnace body 30 are relatively large, the first furnace body 20 and the second furnace body 30 are set independently, which can reduce the 10 Expansion at high temperature leads to mutual extrusion between different material structures, thereby improving the safety and service life of the entire equipment, and facilitating targeted maintenance.

Further, the top of the third area 3 is provided with an auxiliary burner 61 , the upper side of the third area 3 is provided with a slag outlet 62 , and the lower side of the third area 3 is provided with a low matte outlet 63 . The molten slag and low nickel matte complete deep separation in the third area 3 , due to the density difference between solid and liquid, low nickel matte continuously flows out from the low nickel matte outlet 63 , and molten slag is continuously discharged at the slag outlet 62 .

Therefore, the smelting furnace 100 provided by the embodiment of the present application has the integration of melting, reduction and separation, and then does not need multiple converters to realize the continuous process directly from nickel oxide ore to nickel matte production, reducing the process flow and cost.

In order to achieve better use of heat, to improve energy utilization efficiency, in order to achieve the role of saving energy. In the embodiment of the present application, the first furnace shaft 20 and the second furnace shaft 30 are respectively set as the lower molten pool reaction zone and the upper gas phase reaction zone, and the first furnace shaft 20 is respectively set corresponding to the first zone 1 and the second zone 2 There are a first nozzle 21 and a second nozzle 22 for injecting oxygen-enriched air and reducing agent, vulcanizing agent or fuel into the reaction zone; the first nozzle 21 is used to melt the smelting material and the second nozzle 22 is used to The object to be smelted after melting and slagging in the first zone 1 is reduced to produce the target product.

Correspondingly, the first area 1 is provided with a main feeding port 41 on the furnace roof 40 for adding materials such as nickel oxide ore, and the second area 2 is also provided with an auxiliary feeding port 42 on the furnace roof 40 for adding related materials.

The second furnace shaft 30 is provided with secondary oxygen-enriched tuyeres 31 in both the first zone 1 and the second zone 2, which are used for supplementary combustion of CO in the upper gas phase reaction zone, and return the fuel heat to the molten pool reaction zone secondary use. Furnace top 40 is provided with first area 1 and second area 2 common exhaust flue 8, in order to make better use of energy consumption, the first area 1 and second area 2 are collected by an external waste heat boiler (unlabeled). The high-temperature flue gas in the reaction process converts the heat of the high-temperature flue gas into steam for waste heat power generation or for production and domestic use.

The flue gas produced in the first zone 1 and the second zone 2 is combined through the rising flue 8 and enters the waste heat boiler to produce steam. The steam is used for power generation, reducing the dependence on external power loads, and using the same rising flue 8, the heat is relatively large The ascending flue has the characteristics of centralization and higher heat recovery efficiency. And only one set of flue gas recovery device is needed to perform heat recovery and dust removal treatment on the flue gas, so as to realize the effect of simplifying the device and reducing the cost of the device.

Wherein, the ascending flue 8 is provided with a tertiary tuyere 81 for supplementary combustion of CO in the flue gas by blowing in air or oxygen-enriched air. Thereby achieving a better power increase effect.

It can be understood that the embodiment of the present application uses the combustion of CO and oxygen to generate non-toxic carbon dioxide, ΔH=-282KJ/mol, in the thermochemical equation, ΔH is less than 0, and the reaction is exothermic, and because the smelting furnace 100 has a large scale Large, the amount of substances that it participates in the reaction is very large; so that the CO from the first area 1 and the second area 2 accumulates in the uptake flue 8 and burns to generate a large amount of heat, and the waste heat boiler is recycled for secondary use. Compared with multiple The heat loss recovered by the ascending flue is reduced, and the thermal efficiency can be significantly improved.

It should be noted that the secondary oxygen-enriched tuyere 31 can be used to return fuel heat, and the tertiary tuyere 81 is used to completely burn the remaining gas and recover heat, thereby improving energy utilization efficiency.

Aiming at the characteristics of the gas produced by the chemical reaction of low-nickel matte, it has the advantage of not interacting with each other. By setting the ascending flue 8 for common smoke exhaust in the first area 1 and the second area 2, the size of the ascending flue 8 can be reduced. The design is larger, carrying more volume of smoke output so as to obtain more heat at one time, and cooperate with the tertiary tuyere 81 to burn in the concentrated ascending flue 8, improve the final heat recovery efficiency, and provide greater heat energy for the waste heat boiler .

In a modified embodiment based on the embodiment of the present application, in order to better control the gas release amount of the secondary oxygen-enriched tuyere 31 and the tertiary tuyere 81 to save energy, the secondary oxygen-enriched tuyere 31 Perform PID adjustment with the tertiary tuyere 81, such as setting the target temperature in the gas phase reaction zone as T1, and measuring the actual temperature as T2 through the high temperature sensor, the secondary oxygen-enriched tuyere 31 and the tertiary tuyere can be adjusted according to the deviation between the target temperature T1 and the actual temperature T2 81 of the gas release amount for feedback control.

In order to make the melting furnace 100 conform to the stress conditions adapted to the specific size parameters provided by the above embodiments, the melting furnace needs sufficient mechanical strength to carry large-scale materials and melts, and meet the basic ground stress requirements, thereby increasing the integrated The bearing reliability of the melting furnace.

Please continue to refer to FIG. 2 and FIG. 3 , in the embodiment of the present application, a load-bearing frame 50 is provided on the outside of the melting furnace 100 to stabilize the melting furnace 100 and provide better support for the melting furnace 100. The load-bearing frame 50 is used to build on On the foundation, and on the load-bearing frame 50, there is a load-bearing ring beam 51 extending above the first furnace body 20, which is placed on the ground through the first furnace body 20, and the second furnace body 30 and furnace roof 40 are placed on the load-bearing frame in turn 50 on the load-bearing ring beam 51 , so that the load-bearing frame 50 bears the load on the second shaft 30 and the furnace roof 40 .

It can be understood that, since the first furnace shaft 20 and the second furnace shaft 30 are designed to be heavy in size, the first furnace shaft 20 is directly placed on the ground, and the second furnace shaft is placed on the ground by using the load-bearing frame 50 and the load-bearing ring beam 51. The weight transfer of the first furnace body 30 can prevent the second furnace body 30 from being too heavy to squeeze the first furnace body 20 to cause deformation or even accidents, and increase the service life of the smelting furnace 100 on the side. The independent design of the second furnace shaft 30 can be changed separately, avoiding the huge manpower and material resources brought by the overall dismantling of the furnace.

Specifically, the load-bearing frame 50 is also provided with a load-bearing ring beam water jacket 52 . Wherein, there is a free expansion joint with a width of 40 mm to 80 mm between the first shaft 20 and the upper bearing frame 50 . Due to the large size of the smelting furnace, the expansion and contraction space of the first furnace body 20 can be calculated by the material and the expansion formula, which is between 40mm and 80mm so that the first furnace body 20 has a free expansion and contraction space and can be adjusted to the first furnace body. 20 for protection to prevent thermal stress from causing the first furnace body 20 to squeeze the load-bearing frame 50, thereby increasing the overall stability and service life of the melting furnace 100.

It should be noted that this embodiment of the equipment does not specifically limit the application of high/low nickel matte to the smelting furnace 100, and uses the smelting furnace 100 to replace the blowing products of the first nozzle 21 and the second nozzle 22 to complete different processes. In the case that the technology is prior art and no intellectual labor is paid, it all falls within the scope of protection covered by the embodiments of the present application.

Process:

Please refer to Fig. 1 to Fig. 4, on the basis of adopting the smelting furnace provided by the above-mentioned embodiment, also provide a kind of production method of low nickel matte, specifically comprise the following steps:

a. Dry and crush the nickel oxide ore until the water content is 20% to 25%. The particle size of the crushed nickel oxide ore is ≦50mm. Coal or natural gas is used as fuel in the drying process.

b. Add the dried and crushed nickel oxide ore and flux into the first zone 1 of the smelting furnace according to the preset ratio, spray oxygen-enriched air and fuel into the molten pool in the first zone 1 through the first nozzle 21, and the materials are stirred The slag is rapidly melted in the molten pool to form a melt.

Specifically, in this step b, the nickel oxide ore can be put into the furnace after being dried without preheating, the flux is lime or limestone, and the fuel is coal. The mass ratio of nickel oxide ore to calcium and coal is 100:(5-15):(10-20) to feed nickel oxide ore, flux and fuel.

Specifically, in this step b, the volume concentration of oxygen in the oxygen-enriched air sprayed into the molten pool in the first region 1 through the first nozzle 21 is 80-95%, and the pressure of the oxygen-enriched air injected is 0.1-0.2Mpa. The excess coefficient of oxygen and air to fuel is 0.8-0.9, and the temperature of the first zone 1 is controlled to be 1400-1550°C.

c. The melt produced in the first area 1 flows continuously into the second area 2 through the lower channel of the partition wall 7, and sprays reducing agent, vulcanizing agent, and oxygen-enriched air from the second nozzle 22 into the molten pool of the second area 2, and melts The body is reduced and vulcanized to produce low-nickel matte and slag containing 15-30% nickel.

Specifically, in this step c, the reducing agent is coke powder and pulverized coal, the reducing agent is greater than 80% with a particle size of 200 mesh or more, and the mass ratio of nickel oxide ore to the amount of reducing agent added is 100: (10-15); It is at least one of sulfur and calcium sulfate, the vulcanizing agent has a particle size of more than 200 mesh and greater than 80%, and the nickel oxide ore and the vulcanizing agent are fed according to the mass ratio of nickel oxide ore and sulfur at 100:2-3.

Specifically, in this step c, the volume concentration of oxygen in the oxygen-enriched air injected into the second region 2 through the second nozzle 22 is 80-95%, and the pressure of the injected oxygen-enriched air is 0.3-0.4Mpa. The temperature in zone 2 is 1400°C to 1550°C, and the oxygen excess coefficient α is 0.3 to 0.4. The oxygen excess coefficient is the consumption index of reducing agent and oxygen-enriched air injected into the molten pool.

Specifically, in the step c, the reaction time of the reduction and vulcanization of the material in the second zone 2 is 0.5-1.0 h, and the reduction and vulcanization reaction of the melt produces low-nickel matte and slag containing 15-30% nickel.

d. The low nickel matte and slag produced in the second area 2 continuously flow into the third area 3, and the low nickel matte and slag are further separated in the third area 3 to obtain slag containing nickel ≤ 0.1%, and the low nickel matte passes through the low ice The nickel discharge port 63 is discharged intermittently, and the slag is discharged continuously through the slag discharge port 62 for water quenching.

Specifically, in this step d, the low nickel matte and slag produced in the second area 2 continuously flow into the third area 3, and the residence time of the low nickel matte and slag in the third area 3 is ≥0.5h.

e. Inject oxygen-enriched air into the upper gas phase reaction area of the first area 1 and the second area 2 through the secondary oxygen-enriched air nozzle 31, and return the heat obtained from combustion to the molten pool.

Specifically, in this step e, the oxygen-enriched air is injected into the upper gas phase reaction area of the molten pool in the first area 1 and the second area 2 through the secondary oxygen-enriched air nozzle 31 at an angle of 30-55° horizontally downward. °, the volume concentration of oxygen in the oxygen-enriched air injected for the second time is 60-80%, and the pressure of the oxygen-enriched air injected for the second time is 0.05Mpa-0.1Mpa, so as to burn the CO in the gas phase reaction area and burn the heat Return to the molten pool.

f. The high-temperature flue gas produced in the first area 1 and the second area 2 is processed through the ascending flue 8 for heat recovery and dust removal.

Specifically, in this step f, the high-temperature flue gas enters the waste heat boiler through the ascending flue 8 to recover waste heat, and the flue gas enters the bag filter after being cooled by the waste heat boiler. The steam produced is used to generate electricity.

The characteristics and performance of the present application will be further described in detail below in conjunction with specific embodiments. The nickel oxide ore used in the embodiment contains 1.50% nickel, 0.10% cobalt, 18% iron, 21% magnesium oxide, and 35% silicon dioxide.

Example 1

Put the nickel oxide ore into the drying kiln for drying until the water content is 20% to 25%. After drying, it is sieved through the grid, and the undersize is controlled to be less than 50mm. The dried nickel oxide ore and limestone are fed into the first area 1 of the smelting furnace through the main feeding port 41 of the furnace roof 40 according to a preset ratio, and the oxygen-enriched air and pulverized coal are sprayed into the first area 1 through the first nozzle 21 In the molten pool, the pressure of oxygen-enriched air is 0.12Mpa, the excess coefficient of oxygen-enriched air to fuel is 0.85, the temperature of the first zone 1 is controlled at 1500°C, and the material is rapidly melted and slagged in the stirred molten pool under a weak reducing atmosphere. Melt is formed; the melt produced in the first area 1 continuously flows into the second area 2 through the lower channel of the partition wall, and the reducing agent pulverized coal, sulfiding agent sulfur, and oxygen-enriched air are sprayed into the second area 2 from the second nozzle 22 to melt In the pool, the temperature in the second area 2 is controlled to be 1500°C, the oxygen excess coefficient α is 0.3, and the melt is reduced and vulcanized in a strong reducing atmosphere to form low-matte and slag; the low-matte and slag produced in the second area flow continuously In the third zone 3, low nickel matte and slag are further separated in the third zone 3 to obtain slag containing nickel≦0.1%. The low nickel matte is released intermittently through the low nickel matte outlet 63, and the slag continuously releases water through the slag outlet 62. quenching; the high-temperature flue gas produced in the first zone 1 and the second zone 2 is processed through the ascending flue 8 for heat recovery and dust removal.

The final obtained low nickel matte contains 25.34% nickel, 45.19% iron, 1.57% cobalt, and 26.97% sulfur. The recovery rate of nickel metal is 94.02%, the recovery rate of cobalt metal is 86.43%, and the metallization rate of low nickel matte is 0.33. Reduction vulcanization slag contains NiO: 0.10%, FeO: 19.64%, SiO ₂ : 35.21%, CaO: 5.53%, MgO: 20.60%, Al ₂ O ₃ : 4.73%.

Show through above-mentioned embodiment and result thereof, the smelting furnace that the present application is used for smelting nickel matte can directly produce low nickel matte and slag in one furnace, and the required technological process is short, and production efficiency is high, can obtain relatively High grade low nickel matte.

The above are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims (22)

A smelting furnace for smelting nickel matte, characterized in that it comprises The first area (1) is used to melt the material to be smelted to form slag; The second area (2) is used to reduce and vulcanize the smelted material after melting and slagging in the first area (1) to produce the target product; and a third zone (3), for separating said target product; The smelting furnace includes a first furnace body (20) and a second furnace body (30) which are independent from each other in the vertical direction, and the first furnace body (20) and the second furnace body (30) correspond to the first furnace body (20) and the second furnace body (30). First area (1) and second area (2) settings; An ascending flue (8) for common smoke exhaust is arranged above the first area (1) and the second area (2). The smelting furnace according to claim 1, characterized in that, the first furnace shaft (20) and the second furnace shaft (30) are respectively the lower molten pool reaction zone and the upper gas phase reaction zone; the first furnace shaft (20) Corresponding to the first area (1) and the second area (2) are respectively provided with: The first nozzle (21) is used to inject material containing at least oxygen-enriched air into the first area (1) to melt the material to be smelted to form slag; The second nozzle (22) is used to spray materials containing at least oxygen-enriched air into the second area (2) to reduce the smelted material after melting and slagging in the first area (1) to produce the target product . The smelting furnace according to claim 1, characterized in that, the second furnace shaft (30) is provided with a secondary oxygen-enriched tuyere (31) in the first area (1) and the second area (2). ), for supplementary combustion. The smelting furnace according to claim 3, characterized in that a tertiary tuyere (81) is provided in the ascending flue (8) for feeding air or oxygen-enriched air for combustion in the ascending flue . The melting furnace according to claim 1, characterized in that, the first area (1), the second area (2) and the third area (3) are connected, and the first area (1) A partition wall (7) is provided between the second area (2) to separate the first area (1) and the second area (2), the first area (1), the second area (2) and The third zone (3) jointly includes a furnace hearth (10), and a channel is left between the partition wall (7) and the furnace hearth (10), so that the melt in the first zone (1) flows to the Second area (2). The smelting furnace according to claim 5, characterized in that, the partition wall (7) is a double-layer copper water jacket, and the bottom of the bottom copper water jacket of the partition wall (7) is an arc-shaped structure. The melting furnace according to claim 1, characterized in that, the first furnace body (20) is spliced by multi-layer copper water jackets, and the second furnace body (30) is made of refractory materials and horizontal copper water jackets Alternately built by masonry. The melting furnace according to claim 2, characterized in that, the first furnace body (20) is spliced by multi-layer copper water jackets, and the first nozzle (21) and the second nozzle (22) are arranged on On the lowermost copper water jacket of the first shaft (20), the height of the second nozzle (22) is lower than that of the first nozzle (21). The smelting furnace according to claim 7, characterized in that, the uppermost layer of the copper water jacket of the first furnace body (20) expands outwards, and the inclination angle relative to the vertical direction is 10°-18°. The smelting furnace according to claim 1, characterized in that, a load-bearing frame (50) is provided on the outside of the smelting furnace, and a bearing frame (50) is provided on the load-bearing frame (50) to protrude above the first furnace shaft (20). a load-bearing ring beam (51), the second furnace body (30) is placed on the load-bearing ring beam (51) to carry out load-bearing for the second furnace body (30) and transfer the weight to the load-bearing frame (50), the The load-bearing ring beam (51) is provided with a load-bearing ring beam water jacket (52). The melting furnace according to claim 10, characterized in that there is a free expansion joint with a width of 40mm-80mm between the first furnace shaft (20) and the load-bearing ring beam (51). The melting furnace according to any one of claims 1 to 11, characterized in that, the top of the third area (3) is provided with a supplementary heat burner (61), and the upper side of the third area (3) is provided with a The slag outlet (62), the lower side of the third area (3) is provided with a low nickel matte outlet (63). The melting furnace according to any one of claims 1 to 11, characterized in that a depth difference is set between the first area (1) and the second area (2), and along the first area (1) to In the direction of the second area (2), the bottom of the first area (1) and the second area (2) corresponding to the partition wall (7) is provided with a gradient structure (13) whose depth gradually increases along the direction. ). A kind of production method of low nickel matte, is characterized in that, adopts the smelting furnace as described in any one in claim 1-13, specifically comprises the steps: Dry and crush the nickel oxide ore until the water content is 20% to 25%, and the particle size of the nickel oxide ore after crushing is ≦50mm; The dried and crushed nickel oxide ore and flux are added to the first area (1) of the smelting furnace, and oxygen-enriched air and fuel are sprayed into the molten pool of the first area (1), and the materials are rapidly melted and slagged in the stirred molten pool. form a melt; The melt produced in the first area (1) flows continuously into the second area (2), and the reducing agent, vulcanizing agent, and oxygen-enriched air are sprayed into the molten pool in the second area (2), and the melt is reduced and vulcanized to form low ice nickel and slag; The low nickel matte and slag produced in the second area (2) flow into the third area (3) continuously, the low nickel matte and slag are further separated in the third area (3), the low nickel matte is released intermittently, and the slag is continuously released for water quenching ; Inject oxygen-enriched air into the upper gas phase reaction area of the first area (1) and the second area (2), and return the heat obtained from combustion to the molten pool; The high-temperature flue gas produced in the first area (1) and the second area (2) is passed through the ascending flue (8) for waste heat recovery and tail gas treatment. The production method of low nickel matte according to claim 14, characterized in that, the flux is lime or limestone, and the fuel is coal, and the mass ratio of nickel oxide ore to calcium and coal is 100: (5～15 ): (10～20) feed nickel oxide ore, flux and fuel. The production method of low nickel matte according to claim 14, characterized in that, the volume concentration of oxygen in the oxygen-enriched air sprayed into the molten pool of the first region (1) is 80-95%, and the pressure of the oxygen-enriched air sprayed into 0.1-0.2Mpa, the excess coefficient of oxygen-enriched air to fuel is 0.8-0.9, and the temperature of the first zone (1) is controlled to be 1400-1550°C. The production method of low nickel matte according to claim 14, characterized in that, the reducing agent is coke powder and pulverized coal, and the reducing agent is greater than 80% of the particle size of 200 mesh or more, and the addition amount of nickel oxide ore and reducing agent The mass ratio is 100: (10～15); The vulcanizing agent is at least one of sulfur and calcium sulfate, the vulcanizing agent is greater than 80% with a particle size of 200 mesh or more, and the nickel oxide ore and the vulcanizing agent are based on the nickel oxide ore The mass ratio to sulfur is 100:2-3 for feeding. The production method of low nickel matte according to claim 14, characterized in that, the volume concentration of oxygen in the oxygen-enriched air sprayed into the second zone (2) is 80～95%, and the pressure injected into the oxygen-enriched air is 0.3-0.4Mpa, the temperature of the second zone (2) is 1400°C-1550°C, the oxygen excess coefficient α is 0.3-0.4, and the oxygen excess coefficient is the consumption index of the reducing agent and the oxygen-enriched air injected into the molten pool . The production method of low nickel matte according to claim 14, characterized in that, the reduction and vulcanization reaction time of the material in the second zone (2) is 0.5 to 1.0 h, and the melt undergoes a reduction and vulcanization reaction to form a nickel-containing 15 to 30 % low nickel matte and slag. The production method of low nickel matte according to claim 14, characterized in that, the low nickel matte and slag produced in the second zone (2) continuously flow into the third zone (3), and the low nickel matte and slag are in the third zone (3) The internal residence time is ≥0.5h. The production method of low nickel matte according to claim 14, characterized in that, the injection angle of oxygen-enriched air is sprayed into the gas-phase reaction zone on the upper part of the molten pool of the first zone (1) and the second zone (2) for a second time. Horizontally downward at 30-55°, the volume concentration of oxygen in the oxygen-enriched air injected for the second time is 60-80%, and the pressure of the oxygen-enriched air injected for the second time is 0.05Mpa-0.1Mpa, so that the CO in the gas phase reaction area Combustion, return the heat from combustion to the molten pool. The production method of low nickel matte according to claim 14, characterized in that, the high-temperature flue gas enters the waste heat boiler through the ascending flue (8) to recover waste heat, and the flue gas enters the bag filter after being cooled by the waste heat boiler, and the waste heat boiler and The dust recovered by the bag filter is returned to the ingredients, and the steam produced by the waste heat boiler is used for power generation.

Images