CN114234627A

CN114234627A - Double-spiral feeding device, rotary kiln and roasting method for tungsten smelting

Info

Publication number: CN114234627A
Application number: CN202111578340.9A
Authority: CN
Inventors: 王文华; 彭志宏; 龚国平; 周秋生; 洪侃; 申雷霆; 陈东英; 方宣华
Original assignee: Jiangxi Tungsten Industry Co ltd; Central South University
Current assignee: Jiangxi Tungsten Industry Co ltd; Central South University
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2022-03-25

Abstract

The invention provides a double-spiral feeding device, a rotary kiln and a roasting method for tungsten smelting, belonging to the technical field of tungsten industry equipment, wherein the double-spiral feeding device comprises: the feeding outlet of the double-shaft extruding device is hermetically communicated with the feeding inlet of the double-screw conveying device; the double-shaft extrusion device is provided with two extrusion shafts which are arranged in parallel at intervals, the two extrusion shafts rotate oppositely and are used for extruding materials downwards from the upper part to a feeding inlet of the double-screw conveying device, and the extrusion shafts of the double-shaft extrusion device are provided with a plurality of material stirring ribs which are arranged at intervals in the circumferential direction; according to the double-screw feeding device, the two extrusion shafts of the double-screw extrusion device rotate oppositely to extrude materials to the feeding inlet of the double-screw conveying device from the upper part, so that the defect that the materials with high viscosity and humidity form an arched cavity at the feeding inlet of the double-screw conveying device is overcome, and the stability of material supply is improved.

Description

Double-spiral feeding device, rotary kiln and roasting method for tungsten smelting

Technical Field

The invention relates to the technical field of tungsten industry equipment, in particular to a double-spiral feeding device, a rotary kiln and a roasting method for tungsten smelting.

Background

The APT smelting is an indispensable important step in the tungsten industry, and is a process for removing impurities of tungsten in tungsten ore and purifying and refining the tungsten.

Most of the traditional APT smelting is obtained after alkali decomposition or acid decomposition, transformation, impurity removal, evaporation, crystallization and drying, a large amount of strong acid and strong base are used in the process, and the process has the defects of large waste water discharge amount, high salinity, high safety risk, environmental friendliness and high cost. Therefore, the ammonium tungstate solution is obtained by adopting roasting process to perform APT smelting, directly converting minerals into easily-leached mineral components A in a kiln, and directly leaching and transforming by using a leaching agent. The most critical step of the process is to completely mix the materials and then carry out roasting transformation, which directly influences the direct production cost, efficiency and recovery rate.

The equipment adopting the roasting process comprises: the static pushed slab kiln and the rotary kiln are used for ceramic, rare earth and other industries, the automation degree is low, the labor intensity is high, the sealing performance is low, the kiln atmosphere is not adjustable, and the kiln tail gas is not beneficial to recovery. Therefore, most of the roasting processes adopt rotary kilns, such as aluminum smelting industry, cement industry, tungsten industry and the like.

In the tungsten industry, as the process materials have high viscosity and high humidity, an arch-shaped cavity is easily formed in the storage bin when spiral feeding is adopted.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to overcome the defect that an arch-shaped cavity is easily formed in a bin when a feeding device in the prior art performs spiral feeding, so that a double-spiral feeding device and a rotary kiln with the same are provided.

In order to solve the technical problem, the invention provides a double-helix feeding device, which comprises:

the double-helix conveying device is provided with a feeding inlet and a feeding outlet;

the double-shaft extruding device is provided with a feeding inlet and a feeding outlet, and the feeding outlet is hermetically communicated with the feeding inlet of the double-screw conveying device;

the double-shaft extruding device is provided with two extruding shafts which are arranged in parallel at intervals, and the two extruding shafts rotate oppositely when seen from the feeding inlet, so that materials are extruded downwards from the upper part to the feeding inlet of the double-screw conveying device through the two extruding shafts, and the extruding shafts of the double-shaft extruding device are provided with a plurality of material stirring ribs which are arranged at intervals in the circumferential direction.

Optionally, the material stirring rib on the extruding shaft extends axially on the extruding shaft.

Optionally, the material shifting rib is provided with a plurality of sections on the extrusion shaft along the axial direction, and the material shifting rib is arranged at intervals in the circumferential direction of the extrusion shaft.

Optionally, the shaft diameter of the extrusion shaft of the double-shaft extrusion device is larger than that of the screw rod of the double-screw conveying device.

Optionally, the depth of a tooth opening of a material shifting rib on the material extruding shaft is smaller than the depth of a tooth opening of a spiral blade of the double-spiral conveying device.

The invention also provides a double-helix feeding device in any scheme, and the double-helix feeding device is used in tungsten smelting.

The present invention also provides a rotary kiln comprising:

the furnace tube is rotatably arranged on the mounting rack;

in the double-helix feeding device in any one of the above schemes, the feeding outlet of the double-helix conveying device extends into the furnace tube.

Optionally, the furnace tube is obliquely arranged on the mounting rack, the furnace tube is provided with a furnace inlet and a furnace outlet, and the furnace inlet is higher than the furnace outlet.

Optionally, a stirring device is hung between the furnace head and the furnace tail in the furnace tube, and the stirring device is in contact with the inner wall of the furnace tube.

Optionally, the stirring device is a chain, one end of the chain is connected to the furnace end in the furnace tube through a universal joint, and the other end of the chain is connected to the furnace tail in the furnace tube through a universal joint.

Optionally, the furnace tube is externally provided with a rapping device at the furnace head and the furnace tail respectively, the rapping device is arranged on the mounting frame, and the rapping device is driven by the driving device.

The invention also provides a roasting method for tungsten smelting, which adopts the rotary kiln in any one of the schemes.

The technical scheme of the invention has the following advantages:

1. according to the double-screw feeding device provided by the invention, the double-shaft extruding device is hermetically connected at the feeding inlet of the double-screw conveying device and is provided with the two extruding shafts which are arranged in parallel at intervals, the extruding shafts are provided with the plurality of material stirring ribs which are arranged at intervals in the circumferential direction, and materials are extruded from the upper part to the feeding inlet of the double-screw conveying device through the opposite rotation of the two extruding shafts, so that the defect that materials with high viscosity and humidity form an arched cavity at the feeding inlet of the double-screw conveying device is avoided, and the stability of material supply is improved.

2. According to the double-helix feeding device, the material stirring ribs on the material extruding shaft of the double-shaft material extruding device extend along the axial direction of the material extruding shaft and are divided into a plurality of sections, quantitative material extruding can be carried out by controlling the rotating speed of the material extruding shaft, and the feeding speed can be effectively controlled.

3. According to the rotary kiln provided by the invention, the chain is arranged in the furnace tube and used for stirring the materials in the furnace tube and preventing the materials from being bonded on the inner wall of the furnace tube, so that the cleaning effect on the inner wall of the furnace tube is achieved.

4. According to the rotary kiln provided by the invention, the independent knocking device is arranged outside the furnace tube, the knocking device is arranged on the mounting frame of the furnace tube and is driven by the independent driving device, and the driving device can independently control the knocking speed through the controller, so that the knocking speed can be adaptively adjusted according to the field requirement, and the problem of material adhesion in the furnace tube is effectively avoided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a front view of one embodiment of a rotary kiln provided in an example of the present invention.

FIG. 2 is a front view of the double helix feed device of FIG. 1.

Fig. 3 is a top view of the twin-shaft extrusion apparatus of fig. 2.

Fig. 4 is a side view of the rapping device of fig. 1.

Description of reference numerals:

1. a double-helix conveying device; 2. a feed inlet; 3. a feed outlet; 4. a double-shaft extruding device; 5. a feed inlet; 6. a feed outlet; 7. a material extruding shaft; 8. material stirring ribs; 9. a screw rod; 10. a helical blade; 11. a feeding frame; 12. a furnace tube; 13. a mounting frame; 14. a furnace inlet; 15. a furnace outlet; 16. a chain; 17. a tapping device; 18. knocking a hammer; 19. a hammer head; 20. a cylinder; 21. and (4) a bracket.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The rotary kiln provided by the embodiment can be used for a roasting process for tungsten smelting in the tungsten industry.

As shown in fig. 1, a specific embodiment of the rotary kiln provided in this embodiment includes: the double-helix feeding device is arranged on the feeding rack 11, and the furnace tube 12 is arranged on the mounting rack 13. The double-helix feeding device conveys materials through the double-helix conveying device 1, the double-helix conveying device 1 is provided with a feeding outlet 3, and the feeding outlet 3 of the double-helix conveying device 1 extends into a furnace inlet 14 of the furnace tube 12. The furnace tube 12 is obliquely arranged towards the furnace outlet 15, so that the furnace inlet 14 is higher than the furnace outlet 15, and the material in the furnace tube 12 is guided out in the rotating process of the furnace tube 12.

As shown in fig. 2, in the rotary kiln provided in this embodiment, the double spiral feeding device includes: the double-screw extruder comprises a double-screw conveying device 1 and a double-screw extruding device 4, wherein the double-screw conveying device 1 is provided with a feeding inlet 2 and a feeding outlet 3; the double-shaft extrusion device 4 is provided with a feeding inlet 5 and a feeding outlet 6, and the feeding outlet 6 is in sealed communication with the feeding inlet 2 of the double-screw conveying device 1.

As shown in fig. 3, two material extruding shafts 7 arranged at parallel intervals are arranged in the double-shaft material extruding device 4, the two material extruding shafts 7 rotate oppositely to extrude the material downwards to the feeding inlet 2 of the double-screw conveying device 1 from the upper part, a plurality of material stirring ribs 8 arranged at intervals in the circumferential direction are arranged on the material extruding shafts 7 of the double-shaft material extruding device 4, and the material with high viscosity and high humidity is extruded downwards through the dislocation movement of the material stirring ribs 8 on the two material extruding shafts 7.

The double-screw feeding device provided by the embodiment is characterized in that a double-screw extruding device 4 is connected to a feeding inlet 2 of a double-screw conveying device 1 in a sealing mode, the double-screw extruding device 4 is provided with two extruding shafts 7 arranged at parallel intervals, a plurality of outwards protruding material stirring ribs 8 arranged at intervals in the circumferential direction are arranged on the extruding shafts 7, and the extruding shafts 7 rotate in opposite directions to extrude materials to the feeding inlet 2 of the double-screw conveying device 1 from the upper side downwards, so that the defect that materials with high viscosity and high humidity form an arch cavity in the feeding inlet 2 of the double-screw conveying device 1 is overcome, and the stability of material supply is improved. It should be noted that, the opposite rotation of the two extrusion shafts 7 means that, from a top view, the two extrusion shafts 7 rotate in opposite directions, so that the material above can be extruded downwards.

As shown in fig. 3, in the rotary kiln provided in this embodiment, the material shifting rib 8 on the material extruding shaft 7 in the dual-shaft material extruding device 4 extends along the axial direction of the material extruding shaft 7 and is divided into a plurality of sections, and the arrangement can perform quantitative material extruding by controlling the rotation speed of the material extruding shaft 7, so as to effectively control the feeding speed. In addition, as an alternative embodiment, the material shifting bar 8 may also be a whole bar extending in the axial direction on the extruding shaft 7.

As shown in fig. 2, the diameter of the extruding shaft 7 of the double-shaft extruding device 4 is larger than the diameter of the screw rod 9 of the double-screw conveyer 1, so that the extruding speed of the double-shaft extruding device 4 towards the double-screw conveyer 1 can be increased to meet the conveying speed of the double-screw conveyer 1. In addition, the depth of the tooth openings of the material stirring ribs 8 on the material extruding shaft 7 is smaller than the depth of the tooth openings of the spiral blades 10 of the double-screw conveying device 1, so that materials with high viscosity and high humidity are extruded and scattered through the material stirring ribs 8 on the material extruding shaft 7, and the materials are quantitatively fed to the lower double-screw conveying device 1. Then the materials are conveyed to the interior of the furnace tube 12 in time through the helical blades 10 of the double-helix conveying device 1 for heating, drying and reaction, so that the materials are not accumulated. Through the cooperation of the double-shaft extruding device 4 and the double-screw conveying device 1, the automatic quantitative feeding problem that materials with strong viscosity and high humidity enter the furnace can be solved.

As shown in fig. 1, the double-screw conveying device 1 is arranged on a feeding machine frame 11, and the double-screw extrusion device 4 is connected to the double-screw conveying device 1. Therefore, the occupied space of the equipment is saved, and the materials can more quickly fall into the double-screw conveying device 1 from the double-shaft extruding device 4 by utilizing gravity.

As shown in fig. 1, in the rotary kiln provided in this embodiment, the furnace tube 12 is rotatably disposed on a mounting frame 13, the furnace tube 12 is obliquely disposed on the mounting frame 13, the furnace tube 12 has a furnace inlet 14 and a furnace outlet 15, and the furnace inlet 14 is higher than the furnace outlet 15. The stirring device is hung between the furnace head and the furnace tail in the furnace tube 12 and is in contact with the inner wall of the furnace tube 12, and when the furnace tube 12 rotates on the mounting frame 13, the stirring device is always positioned below the inner wall of the furnace tube 12 under the action of gravity, so that materials below the inner side of the furnace tube 12 are stirred, the inner wall of the furnace tube 12 is cleaned, and the materials are prevented from being bonded on the inner wall of the furnace tube 12. The materials are turned in the furnace tube 12, so that dust raising caused by turning is avoided, the materials are prevented from being bonded and agglomerated, and the solid-solid reaction of the materials is better realized.

As shown in fig. 1, in the rotary kiln provided in this embodiment, the stirring device in the furnace tube 12 is a chain 16, two ends of the chain 16 are respectively connected to the furnace head and the furnace tail in the furnace tube 12 through universal joints, and when the furnace tube 12 rotates, two ends of the chain 16 rotate around the universal joints, so that the chain 16 does not rotate, and only slides on the inner wall of the furnace tube 12, so as to better clean the inner wall of the furnace tube 12.

As shown in fig. 1 and 4, in the rotary kiln provided in this embodiment, the furnace tube 12 is provided with a rapping device 17 at the furnace end and the furnace tail, respectively, the rapping device 17 is disposed on the mounting frame 13, and the rapping device 17 is driven by a driving device. The rapping device 17 arranged outside the furnace tube 12 is driven by a separate driving device, and the driving device can control the rapping speed independently through a controller, so that the rapping speed can be adjusted adaptively according to the field requirement, and the problem of material adhesion in the furnace tube 12 is effectively avoided. In addition, in the rotary kiln provided in this embodiment, the heat insulating material is disposed at the middle position of the furnace tube 12, so that a solid-solid reaction of the material inside the furnace tube 12 can be ensured, and the rapping device 17 is disposed at the furnace end and the furnace tail of the furnace tube 12, so that the heat insulating material is not affected. In the inside middle section of boiler tube 12, guarantee through chain 16 that the material is not sticky, guarantee through rapping device 17 that the material is not sticky at the both ends of boiler tube 12, through the cooperation of both, realize the continuous stable work of rotary kiln.

As shown in fig. 4, the rapping device 17 comprises: the knocking hammer 18 is rotatably connected to a support 21, and the support 21 is fixed on the mounting frame 13. In addition, the rapping hammer 18 may also be directly rotatably connected to the mounting frame 13. The head of the knocking hammer 18 is provided with a hammer head 19 with a larger diameter, the tail of the knocking hammer 18 is rotatably connected to the driving end of the driving device, the driving device can be an air cylinder 20, and the air cylinder 20 can control the knocking frequency through a relay. In addition, as an alternative embodiment, the driving device may also be an oil cylinder, an electric push rod, a motor, or other driving devices.

In the rotary kiln provided by the embodiment, the rapping device 17 is independently arranged outside the furnace tube 12, the rapping hammer 18 is controlled by the cylinder 20 to be rapped onto the furnace tube 12, and the rapping frequency is controlled by the relay, so that the stability of the rapping device 17 is well solved, the rapping strength and frequency are not limited by the rotating speed of the furnace tube 12, and the process regulation and control are mutually independent; the materials are scattered and quantitatively extruded into the double-screw conveying device 1 through the double-shaft extruding device 4, so that the problem that the materials with high viscosity and high humidity are often blocked at the feeding inlet 2 of the double-screw conveying device 1 and are required to be manually blocked is well solved, and continuous automatic feeding is realized; the chain 16 is arranged in the furnace tube 12, so that the functions of scraping materials stuck on the wall and turning over the materials are achieved, and the defect of high dust emission is avoided.

When the double-screw feeding device provided by the embodiment is applied to tungsten smelting, the double-screw feeding device can be used for conveying materials to be smelted, and the double-screw extruding device is connected to the feeding inlet of the double-screw conveying device in a sealing mode, so that the materials are extruded from the upper part to the feeding inlet of the double-screw conveying device through opposite rotation of the two extruding shafts of the double-screw extruding device, the defect that the materials with high viscosity and humidity form an arch cavity at the feeding inlet of the double-screw conveying device is overcome, and the stability of material supply is improved.

The rotary kiln provided by the embodiment can be used for a roasting process of tungsten smelting, and particularly, after materials are conveyed into a furnace tube through a double-helix feeding device, the materials inside the furnace tube are roasted.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the scope of the invention.

Claims

1. A double helix feeding device, characterized by comprising:

the double-helix conveying device (1) is provided with a feeding inlet (2) and a feeding outlet (3);

the double-shaft extruding device (4) is provided with a feeding inlet (5) and a feeding outlet (6), and the feeding outlet (6) is hermetically communicated with the feeding inlet (2) of the double-screw conveying device (1);

the double-shaft extruding device (4) is provided with two extruding shafts (7) which are arranged in parallel at intervals, the two extruding shafts (7) rotate oppositely when seen from the feeding inlet (5), so that materials are extruded downwards from the upper part to the feeding inlet (2) of the double-screw conveying device (1) through the two extruding shafts (7), and the extruding shafts (7) of the double-shaft extruding device (4) are provided with a plurality of material stirring ribs (8) which are arranged at intervals in the circumferential direction.

2. A double spiral feeding device according to claim 1, characterized in that the stirring bar (8) on the extrusion shaft (7) extends axially on the extrusion shaft (7).

3. The double-helix feeding device according to claim 2, characterized in that the material ejecting rib (8) is provided with a plurality of sections along the axial direction on the extrusion shaft (7), and the material ejecting rib (8) is arranged at intervals along the circumferential direction of the extrusion shaft (7).

4. A double spiral feeding device according to any one of claims 1-3, characterized in that the depth of the tooth openings of the material stirring ribs (8) on the extrusion shaft (7) is smaller than the depth of the tooth openings of the spiral blades (10) of the double spiral conveying device (1).

5. Use of a double spiral feed device according to any one of claims 1 to 4 in tungsten smelting.

6. A rotary kiln, comprising:

the furnace tube (12) is rotatably arranged on the mounting rack (13);

the double spiral feeding device of any one of claims 1-4, the feeding outlet (3) of the double spiral conveying device (1) extends into the furnace tube (12).

7. The rotary kiln according to claim 6, characterized in that the furnace tube (12) is arranged obliquely on the mounting frame (13), the furnace tube (12) having a furnace inlet (14) and a furnace outlet (15), the furnace inlet (14) being higher than the furnace outlet (15).

8. The rotary kiln according to claim 6, characterized in that a stirring device is hung in the furnace tube (12) between the furnace head and the furnace tail, and the stirring device is in contact with the inner wall of the furnace tube (12).

9. The rotary kiln according to any one of claims 6-8, characterized in that the furnace tube (12) is provided with rapping devices (17) at the furnace head and furnace tail, respectively, the rapping devices (17) being arranged on the mounting frame (13), the rapping devices (17) being driven by a driving device.

10. A roasting method for tungsten smelting is characterized by comprising the following steps: use of a rotary kiln according to any one of claims 6 to 9.