Steam drying system and method for copper smelting intermediate material

Abstract

The invention discloses a steam drying system and method for a copper smelting intermediate material. The steam drying system comprises an arch breaker, a double-screw feeder, a paddle dryer, a scraper elevator, a mixing stirrer, an extrusion granulator, a material distributor, a belt dryer and a spray tower. The method comprises the following steps: drying a low-viscosity material of the copper smelting intermediate material through a paddle dryer, mixing the low-viscosity material with a high-viscosity material, sequentially performing wet granulation and steam drying to obtain a granular material, and finally directly feeding the granular material into a converter for treatment instead of drying through a drying kiln and a steam dryer and remelting through a flash furnace. Therefore, the reaction conditions of the drying kiln, the steam dryer and the flash furnace are improved, the conditions of adhesion, corrosion and the like of a coil pipe of the steam dryer are effectively relieved, the heat exchange efficiency is improved, the service lives of the drying kiln, the steam dryer and the flash furnace boiler pipe are effectively prolonged, and the operation stability of key core equipment and facilities is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of dehydration of copper smelting intermediate materials, and more particularly to a steam drying system and method for copper smelting intermediate materials. Background Art

[0002] Copper smelting processes are complex, and the resulting intermediate materials are often element-rich, poorly reactive work-in-progress, such as black copper sludge, copper filter cake, and washing residue. To improve the recovery rate of copper and trace valuable elements, and enhance production efficiency, it is essential to recycle these intermediate materials whenever possible.

[0003] However, the intermediate materials have high water content and complex composition, so they need to be dried before being returned to the furnace. In the prior art, the intermediate materials are added to the copper concentrate by spreading, and after the pre-drying process, they are returned to the flash furnace for pyrolysis. However, the intermediate materials contain impurity elements such as fluorine and chlorine. When entering the flash smelting, they are prone to cause serious corrosion to the steam dryer coil and the flash furnace boiler system, and at the same time have a great impact on the stability of the flash furnace condition. For this reason, after drying the intermediate materials (i.e., wet slag), they are directly put into the converter without entering the flash furnace to reduce their impact. This is a new idea for wet slag pyrolysis treatment that the copper smelting industry needs to explore.

[0004] Prior art 1 (Announcement No. CN201593014U, Application Date: 2009.12.8) discloses a sludge granulation and drying device, including a sludge bin, an additive bin, an additive elevator, a hollow paddle dryer, a briquetting machine, a belt dryer, a return material elevator, a coal hopper, and an exhaust gas treatment device. The screw pump and the additive elevator respectively input the sludge and additive into the hollow paddle dryer for mixing and pre-drying to a moisture content of 60-50%, and then enter the upper working surface heating briquetting machine under the action of gravity to be pressed into 30-40mm particles, and then enter the lower belt dryer under the action of gravity for deep drying. The sludge granule product with a moisture content of less than 20% and a diameter of 20-30mm is dried and enters the coal hopper under the action of gravity for incineration. The granulation and drying exhaust gas generated in the system is collected and sent to the exhaust gas treatment device for harmless treatment. The materials processed by the prior art 1 are different from those of the present invention. In addition, the arch breaker, mixer, distributor and other equipment are not disclosed, and low-viscosity materials and high-viscosity materials are not treated differently. Summary of the Invention

[0005] In view of this, the present invention provides a steam drying system and method for copper smelting intermediate materials. The copper smelting intermediate materials (i.e., wet slag) are treated according to their viscosity and then dried. The materials are directly fed into the converter without entering the flash furnace, thereby reducing the impact.

[0006] On the one hand, the present invention discloses a steam drying system for copper smelting intermediate materials, comprising: an arch breaker, a double-screw feeder, a paddle dryer, a scraper elevator, a mixer, an extrusion granulator, a material distributor, a belt dryer, and a spray tower, wherein:

[0007] The arch breaker is located above the double-screw feeder, and the discharge end of the arch breaker is connected to the feed end of the double-screw feeder. The arch breaker is used to prevent the copper smelting intermediate material from arching and accumulating;

[0008] The double-screw feeder is located below the arch breaker, and the discharge end of the double-screw feeder is connected to the feed end of the paddle dryer;

[0009] The paddle dryer includes a main shaft and paddles, and steam is passed through the paddle dryer. The discharge end of the paddle dryer is located above the scraper elevator and is connected to the feed end of the scraper elevator. The scraper chain of the scraper elevator is set at an inclination angle of 40°-65°.

[0010] The discharge end of the scraper elevator is connected to the feed end of the mixing mixer;

[0011] The mixing and stirring machine is located above the extrusion granulator, and the discharge end of the mixing and stirring machine is communicated with the feed end of the extrusion granulator;

[0012] The extrusion granulator is located above the material distributor, and the discharge end of the extrusion granulator is connected to the feed end of the material distributor;

[0013] The discharging end of the material distributing machine is connected to the feeding end of the belt dryer;

[0014] The belt dryer is steam-heated and includes at least four drying units, each of which has a mesh belt. Each drying unit is equipped with a hot air circulation fan and a steam heat exchanger. Circulating hot air and fresh air enter the drying unit and pass through the mesh belt and the material on the mesh belt from bottom to top, forming a left-right cross circulation. A moisture outlet is provided on the side of the belt dryer, and moisture is discharged from the moisture outlet.

[0015] A hopper is provided below the discharge end of the belt dryer;

[0016] The paddle dryer and the belt dryer are both provided with an exhaust port at the top, and the exhaust port is connected to one end of a first smoke exhaust pipe. The air inlet of the spray tower is located at the bottom, and the other end of the first smoke exhaust pipe is connected to the air inlet of the spray tower. The top of the spray tower is connected to one end of a second smoke exhaust pipe, and the other end of the second smoke exhaust pipe is connected to a smoke exhaust fan.

[0017] Optionally, a butterfly valve is installed at the inlet of the smoke exhaust fan to control the amount of smoke exhaust.

[0018] Optionally, the paddle of the paddle dryer is a double-shaft, wedge-shaped hollow paddle.

[0019] In another aspect, the present application discloses a steam drying method for copper smelting intermediate material, which uses the steam drying system, and the copper smelting intermediate material includes high-stickiness material and low-stickiness material, wherein the high-stickiness material is wet-process slag that sticks to the main shaft and the blade of the paddle dryer at a drying temperature of 110-120℃, and the low-stickiness material is wet-process slag that does not stick to the main shaft and the blade of the paddle dryer at a drying temperature of 110-120℃, and the steam drying method includes:

[0020] The low-stickiness material enters an arch breaker, which disperses the low-stickiness material, and then the dispersed low-stickiness material enters a double-screw feeder below the arch breaker, which feeds the dispersed low-stickiness material into the paddle dryer.

[0021] The dispersed low-stickiness material is dried in the paddle dryer, steam pressure is controlled within 0.8MPa, and the temperature is less than 180℃, and the low-stickiness material is changed into powder after drying in the paddle dryer, and the moisture content is reduced to less than 10%.

[0022] The powder produced by the paddle dryer falls onto the scraper of the scraper elevator, and the powder is carried into the mixing blender by the scraper elevator.

[0023] The powder and the high-stickiness material are added into the mixing blender, and the mass ratio of the powder to the high-stickiness material is 4:1, and the moisture content of the mixed material is 20-25% after mixing.

[0024] The mixed material is added into the extrusion granulator to form long-strip granular material, the diameter of the long-strip granular material is 10mm, and the length is 20-40mm, the long-strip granular material falls onto the feeding belt of the distributor, and the long-strip granular material enters the mesh belt of the belt dryer through the feeding belt of the distributor, and the moisture content of the long-strip granular material is reduced to less than 8% after drying in the belt dryer, and then the long-strip granular material falls into the hopper below the discharge end of the belt dryer.

[0025] Optionally, the material drying tail gas from the paddle dryer and the top exhaust port of the belt dryer enters the first exhaust pipe, the tail gas of the exhaust pipe passes through the spray tower, the dust particles in the tail gas are separated by the centrifugal force, thrown to the inner wall of the cylinder of the spray tower, adsorbed by the water film flowing on the inner wall of the cylinder, and flows to the bottom and is discharged through the dust discharge port, and the tail gas from the top of the cylinder of the spray tower enters the second exhaust pipe and is guided to the exhaust fan.

[0026] Compared with the prior art, the steam drying of copper smelting intermediate material and the method provided by the application at least achieve the following beneficial effects:

[0027] The copper smelting intermediate material is subjected to the wet granulation steam drying method to obtain granular material, and finally is directly fed into a converter for treatment, so that the drying kiln, the steam dryer and the flash furnace reaction condition are improved, the steam dryer coil sticking, corrosion and the like are effectively alleviated, the heat exchange efficiency is improved, the service life of the drying kiln, the steam dryer and the flash furnace boiler pipe is effectively prolonged, and the operation stability of the key core equipment and facilities is improved.

[0028] Of course, it is not necessary for any product implementing the application to simultaneously achieve all the technical effects described above.

[0029] Other features of the application, and their advantages, will become apparent from the following detailed description of exemplary embodiments of the application, with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0031] Figure 1 is a structure schematic diagram of a steam drying system of copper smelting intermediate material provided by the application;

[0032] Figure 2 is a structure schematic diagram of an arch breaker and a double-spiral feeder;

[0033] Figure 3 is a structure schematic diagram of an arch breaker, a double-spiral feeder and a paddle dryer;

[0034] Figure 4 is a structure schematic diagram of a mixing blender, an extrusion granulator and a distributor;

[0035] Figure 5 is a structure schematic diagram of a distributor and a belt dryer;

[0036] Figure 6 is a structure schematic diagram of a spray tower;

[0037] Figure 7 is a flow chart of a steam drying method of copper smelting intermediate material provided by the present application. DETAILED DESCRIPTION

[0038] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions, and numerical values set forth in these embodiments are not limiting of the scope of the present application unless otherwise specifically stated.

[0039] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the scope of the application its application or uses.

[0040] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, the techniques, methods, and apparatus should be construed as being a part of the specification, where appropriate.

[0041] In all of the examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0042] It should be noted that like reference numerals and letters in the various figures indicate similar items, and thus, once any term is defined in one figure, it is not necessary to discuss it further in subsequent figures.

[0043] Example 1

[0044] In combination Figures 1 to 6 , Figure 1 is a structural schematic diagram of a steam drying system of copper smelting intermediate material provided by the present application; Figure 2 is a structural schematic diagram of an arch breaker and a double helix feeder; Figure 3 is a structural schematic diagram of an arch breaker, a double helix feeder, and a paddle dryer; Figure 4 is a structural schematic diagram of a mixing blender, an extrusion granulator, and a distributor; Figure 5 is a structural schematic diagram of a distributor and a belt dryer;

[0045] Figure 6 is a structural schematic diagram of a spray tower. The present embodiment provides a steam drying system of copper smelting intermediate material, as shown in Figure 1 and Figure 6 , the steam drying system includes an arch breaker 1, a double helix feeder 2, a paddle dryer 3, a scraper elevator 4, a mixing blender 5, an extrusion granulator 6, a distributor 7, a belt dryer 8, and a spray tower 11.

[0046] The arch breaker 1 is located above the double-screw feeder 2. The discharge end of the arch breaker 1 is connected to the feed end of the double-screw feeder 2. The arch breaker 1 is used to prevent the accumulation of arches in the copper smelting intermediate materials.

[0047] The double-screw feeder 2 is located below the arch breaker 1, and the discharge end of the double-screw feeder 2 is connected to the feed end of the paddle dryer 3;

[0048] The paddle dryer 3 includes a main shaft and paddles, and steam is passed through the paddle dryer 3. The discharge end of the paddle dryer 3 is located above the scraper elevator 4 and is connected to the feed end of the scraper elevator 4. The scraper chain of the scraper elevator 4 is set at an inclination angle of 40°-65°.

[0049] The discharge end of the scraper elevator 4 is connected to the feed end of the mixing mixer 5;

[0050] The mixer 5 is located above the extrusion granulator 6, and the discharge end of the mixer 5 is connected to the feed end of the extrusion granulator 6;

[0051] The extrusion granulator 6 is located above the material distributor 7, and the discharge end of the extrusion granulator 6 is connected to the feed end of the material distributor 7;

[0052] The discharging end of the material distributing machine 7 is connected to the feeding end of the belt dryer 8;

[0053] The belt dryer 8 is steam-heated and includes at least four drying units, each of which has a mesh belt. Each drying unit is equipped with a hot air circulation fan and a steam heat exchanger. The circulating hot air and fresh air enter the drying unit and pass through the mesh belt and the material on the mesh belt from bottom to top, forming a left-right cross circulation. The moisture outlet is set on the side of the belt dryer 8, and the moisture is discharged from the moisture outlet.

[0054] A hopper 14 is provided below the discharge end of the belt dryer 8;

[0055] The tops of the paddle dryer 3 and the belt dryer 8 are both provided with exhaust ports, which are connected to one end of the first smoke exhaust pipe 10. The air inlet of the spray tower 11 is located at the bottom, and the other end of the first smoke exhaust pipe 10 is connected to the air inlet of the spray tower 11. The top of the spray tower 11 is connected to one end of the second smoke exhaust pipe 13, and the other end of the second smoke exhaust pipe 13 is connected to the smoke exhaust fan 9.

[0056] Specifically, the arch breaker 1 is a specialized device used to address arching and blockage issues in equipment such as silos, hoppers, and pipelines. By instantaneously releasing high-pressure gas or mechanical vibration, it destroys the arched structure formed by the material, allowing it to resume flow and ensuring the continuity and stability of the production process. In this embodiment, the arch breaker 1 is used to prevent the accumulation of materials during copper smelting.

[0057] The arch breaker 1 in the present invention can be a pneumatic arch breaker 1 or a mechanical vibration arch breaker 1, both of which adopt the structure in the prior art. The pneumatic arch breaker 1 uses compressed air to release instantly to generate impact force, and directly acts on the material accumulation area through a directional jet of air to destroy the material arch bridge structure. For example, a KQP-B pneumatic arch breaker 1 can be used, with a volume range of 50L-300L, a working pressure of 0.4MPa-0.8MPa, and an impact force of up to 1580N-5100N. The mechanical vibration arch breaker 1 generates mechanical vibration through a vibration generator (such as a roller oscillator or an electromagnetic exciter), which is transmitted to the wall of the silo to loosen the material.

[0058] The low-viscosity material in the present invention is broken up after entering the silo arch breaker 1, and then passes through the double-screw feeder 2 below the silo arch breaker 1 and enters the KJG-35 paddle dryer 3 for drying (the drying process is the intermediate material contact heat exchange stage).

[0059] The double-screw feeder 2 rotates in a closed trough by a power shaft with spiral blades. The material is first dispersed by a breaker 1. When the material enters the screw groove composed of the twin screws below, the material in the screw groove will continuously rotate with the rotation of the screw blades by relying on the gravity of the material itself and the friction between the material and the screw groove. The material moves forward continuously under the push of the screw blades, realizing continuous material transportation. The double-screw feeder is mainly composed of a body, a main shaft, a transmission mechanism and other parts. The double-screw feeder 2 in this embodiment can adopt the structure in the prior art, which is not specifically limited here.

[0060] The material is continuously fed into the paddle dryer 3 by the double screw feeder 2. The paddle dryer 3 has the structure of the prior art, in which a paddle shaft rotates under the drive of a motor chain, and the rotating paddle shaft drives another paddle shaft through gear engagement. The material moves to the other end under the drive of the paddle and is dried by the paddle and the shell. The paddle of the paddle dryer 3 can be a double shaft or a wedge-shaped hollow paddle with steam flowing through the inside and a rotary joint for steam introduction and discharge at the shaft end. The two paddle shafts arranged in the paddle dryer 3 are staggered, the inner shell is made in the shape of "W", the paddle and the inner shell have a certain gap, the inner shell and the outer shell form a jacket, a rotary joint for heat medium introduction and discharge is arranged at the shaft end, and the heat medium flows through the shell jacket and the hollow stirring shaft through the rotary joint. The hollow stirring shaft has different internal structures according to the type of the heat medium to ensure the best heat transfer effect. The paddle dryer 3 of the embodiment uses steam as the heating medium, the heating medium is divided into two paths, and enters the shell jacket and the paddle shaft lumen respectively to heat the body and the paddle shaft simultaneously to heat and dry the material by conduction. The dried material is continuously fed into the drying machine by the screw feeder. After the material enters the body, the material is turned and stirred by the rotation of the paddle, the heating interface is constantly updated, the material is heated sufficiently, and the surface moisture of the material is evaporated. At the same time, the material is transported along the spiral track to the discharge end with the rotation of the paddle shaft, and the material is continuously stirred to evaporate the moisture. Finally, the dried and uniform qualified product is discharged from the discharge end. The paddle dryer 3 in the embodiment is a KJG-35 type.

[0061] In the embodiment, the material is dried by the paddle, the intermediate material is in the form of powder (i.e. powder dry material), and the moisture is reduced from 60% to below 10%. At this time, the intermediate material (i.e. low viscosity material) is converted into dry material.

[0062] The material discharged from the paddle dryer 3 falls onto the scraper of the scraper elevator 4. The scraper elevator 4 has the structure of the prior art, which mainly consists of a closed shell, a scraper chain, a driving device, a tensioning device, a head wheel, a tail wheel and the like. Among them, the scraper chain is the core component, which is composed of a scraper and a chain and is responsible for pushing the material to move; the head wheel and the tail wheel are used to support and guide the operation of the scraper chain; the driving device provides power to make the scraper chain move in a cycle; and the tensioning device is used to adjust the tightness of the scraper chain to ensure the normal operation of the equipment.

[0063] The scraper chain of the scraper elevator 4 is arranged at an inclination angle of 40°-65°. It can be understood that if the inclination angle of the scraper chain is too small, the scraper elevator 4 needs a larger space to be arranged at the feeding end above the mixing blender 5. If the inclination angle of the scraper chain is too large, although the space occupied by the scraper elevator 4 can be reduced, the material on the scraper chain is prone to slide off during the transmission. In the embodiment, the scraper chain is arranged at an inclination angle of 40°-65°, that is, the space occupied by the scraper elevator 4 is not increased, and the material is not caused to slide off during the transmission.

[0064] The material is brought into the mixing blender 5 from bottom to top by the scraper elevator 4. The mixing blender 5 in the embodiment adopts the structure in the prior art, and is composed of a barrel, a rack, a stirring shaft, a shaft seal, a stirrer, a transmission device, a charging container and the like. The stirrer is a core component, and the stirrer includes a paddle stirrer, a turbine stirrer and the like, which are not limited here.

[0065] In the embodiment, the powder dry material and the high-viscosity material are mixed. During the mixing, the powder material (dry material) and the high-viscosity material (wet material) are added into the barrel of the mixing blender 5 at a mass ratio of 4:1. If the mass ratio of the powder material (dry material) and the high-viscosity material (wet material) is too low, the high-viscosity material is too much, which is not conducive to uniform stirring, and the high-viscosity material is prone to adhere to the stirring shaft, affecting the stirring. If the mass ratio of the powder material (dry material) and the high-viscosity material (wet material) is too high, the powder material (dry material) is too much, and the high-viscosity material is too less, which is not conducive to the consumption of the copper smelting intermediate material. In the embodiment, the powder material (dry material) and the high-viscosity material (wet material) are mixed at a mass ratio of 4:1, that is, the high-viscosity material is not too much to affect the stirring, and the high-viscosity material of the copper smelting intermediate material can be consumed.

[0066] After the dry material and the wet material are mixed, the mixed material is obtained. The moisture content of the mixed material is between 20% and 25%. The mixed material is added into the extrusion granulator 6 for granulation.

[0067] The extrusion granulator 6 achieves wet granulation through mechanical extrusion. High pressure is applied by counter-rotating rollers, prompting the material particles to bond and recombine to form granules. The operating principle is as follows: After the material enters the device, air between the powder particles is expelled, causing the particles to rearrange and eliminate gaps. Under the action of high pressure, molecular affinity is generated between the particles, forcing them into a cylindrical shape. Finally, a rotating cutter cuts the particles into the desired short cylindrical granules. Some models can omit the drying step and directly process materials such as graphite powder for extrusion molding. The extrusion granulator 6 in this embodiment adopts a structure known from the prior art, specifically the DJY-180 model. The mixed material is added to the hopper of the extrusion granulator 6 and enters the machine cavity through the feed port at the bottom of the hopper. The rotating screw compacts and mixes the material, propelling it toward the die head. It is finally extruded through the discharge orifice at the die head to form elongated granular material. The elongated granules have a diameter of 10 mm and a length of 20 mm to 40 mm.

[0068] The long strip granular material naturally falls onto the feeding belt of the BL-1200 swing material distributor 7.

[0069] The long strip of granular material falls onto the feeding belt of the material distributor 7. Under the combined action of the belt conveyor and the left and right swing of the swing motor, the material is evenly laid on the mesh belt at the feeding end of the belt dryer 8. The material distributor 7 in this embodiment adopts the structure of the prior art.

[0070] The belt dryer 8 utilizes existing technology, featuring a single-layer conveyor belt (mesh belt) inside. The long, granular material is evenly laid onto the mesh belt and then moved in a single direction to dry. The belt dryer 8 utilizes steam heating, with four drying units housed within the dryer. Each unit is equipped with a hot air circulation fan and a steam heat exchanger. Circulating hot air and fresh air enter the dryer through a side duct and then pass from bottom to top through the mesh belt and the material on it, forming a left-right cross-circulation system. A moisture drain port is located on the side of the belt dryer 8, allowing some moisture to be discharged from the side. After belt drying, the moisture content of the long, granular material is reduced from 25% to below 8%. The dried, long, granular material naturally falls into a hopper 14 below the discharge end of the belt dryer 8.

[0071] It should be noted that the paddle dryer 3 and the belt dryer 8 will produce waste gas, which needs to be treated by the spray tower 11 at this time. The spray tower 11 introduces industrial waste gas into the tower through a fan, and the waste gas is in countercurrent contact with the spray liquid in the tower. The spray liquid is atomized by the nozzle to form fine droplets, and mass transfer reaction occurs with the pollutants in the waste gas. For water-soluble pollutants (such as some VOCs), they can be directly dissolved in the droplets; for acidic or basic gases (such as hydrogen chloride and ammonia), they are converted into harmless salts through acid-base neutralization reaction. The packing layer in the tower can increase the gas-liquid contact area and time, and improve the purification efficiency. The treated gas is dewatered by the demisting layer and meets the emission standard, and the spray liquid is recycled and supplemented regularly. The spray tower 11 of the present embodiment adopts the structure of the prior art, the main body is a hollow cylindrical body, the top is provided with a liquid sprayer, and the inside is configured with multiple layers of spray devices, packing layers and demisting devices. The spray system delivers the spray liquid to the nozzle at the top of the tower through a pipeline, the packing layer uses solid materials such as Raschig rings and Pall rings to increase the gas-liquid contact area, and the demister realizes gas-liquid separation through wave-shaped plates or baffles. The equipment is designed with two layers of spraying and three layers of filtering, the atomization upper spraying process prolongs the gas-liquid exchange time, and ensures the purification effect.

[0072] Optionally, a butterfly valve is installed at the inlet of the exhaust fan 9 for controlling the exhaust amount.

[0073] The material drying tail gas from the top exhaust port of the paddle dryer 3 and the belt dryer 8 enters the first exhaust pipe 10, and the tail gas of the first exhaust pipe 10 passes through the spray tower 11 and is introduced from the lower part of the cylinder in a tangential direction, rotates upward, and the dust particles in the tail gas are separated by the centrifugal force and thrown to the inner wall of the cylinder, are adsorbed by the water film flowing on the inner wall of the cylinder, flow to the bottom cone, and are unloaded through the dust discharge port. After the tail gas from the top of the cylinder of the spray tower 11 enters the second exhaust pipe 13, it is connected to the exhaust fan 9, a manual butterfly valve is installed at the inlet of the fan to control the exhaust amount, and the tail gas is finally discharged through the external chimney under the action of the fan.

[0074] The low-viscosity material of the copper smelting intermediate material is first dried by the paddle dryer 3, then mixed with high-viscosity material, and then sequentially subjected to wet granulation and steam drying to obtain granular material, which is finally directly fed into the converter for treatment, without being dried in a drying kiln, steam dryer and flash furnace for reprocessing, thereby improving the reaction conditions of the drying kiln, steam dryer and flash furnace, effectively relieving the problems of steam dryer coil adhesion and corrosion, improving the heat exchange efficiency, effectively prolonging the service life of the drying kiln, steam dryer and flash furnace boiler pipes, and improving the operation stability of the key core equipment and facilities.

[0075] Example 2

[0076] In combination Figures 1 to 6 , and with reference to Figure 7This embodiment provides a steam drying method for copper smelting intermediate materials disclosed in the present invention. The above-mentioned steam drying system is used. The copper smelting intermediate materials include high-viscosity materials and low-viscosity materials. The high-viscosity materials are wet slag that adheres to the main shaft and blades of the paddle dryer 3 at a drying temperature of 110°C to 120°C, and the low-viscosity materials are wet slag that does not adhere to the main shaft and blades of the paddle dryer 3 at a drying temperature of 110°C to 120°C. The steam drying method includes:

[0077] The low-viscosity material enters the silo and is broken up by the arch breaker 1. The low-viscosity material then enters the double-screw feeder 2 below the arch breaker 1. The double-screw feeder 2 feeds the broken-up low-viscosity material into the paddle dryer 3.

[0078] The dispersed low-viscosity material is dried in the paddle dryer 3. The steam pressure is controlled within 0.8 MPa and the operating temperature is less than 180°C. After being dried in the paddle dryer 3, the low-viscosity material becomes a powdered dry material with the moisture content reduced to less than 10%.

[0079] The powdered dry material produced at the discharge end of the paddle dryer 3 falls onto the scraper of the scraper elevator 4, and the scraper elevator 4 brings the powdered dry material from bottom to top into the mixing mixer 5;

[0080] Add powdered dry material and high-viscosity material into the mixer 5, the mass ratio of powdered dry material to high-viscosity material is 4:1, and after mixing evenly, the moisture content of the mixed material is 20% to 25%;

[0081] The mixed material is added into the extrusion granulator to form long strip granular materials with a diameter of 10 mm and a length of 20 mm to 40 mm. The long strip granular materials fall onto the feeding belt of the distributor 7, and pass through the feeding belt of the distributor 7. The long strip granular materials enter the mesh belt of the belt dryer 8. After being dried by the belt dryer 8, the moisture content of the long strip granular materials is reduced to below 8%, and then fall into the hopper 14 below the discharge end of the belt dryer 8.

[0082] Specifically, copper smelting intermediate material (wet slag) can be divided into high-viscosity and low-viscosity materials based on different material properties. At a drying temperature of 110°C-120°C, wet slag that easily adheres to the main shaft and blades of the paddle dryer 3 is considered high-viscosity; wet slag that does not adhere to the main shaft and blades of the paddle dryer 3 is considered low-viscosity.

[0083] Low-viscosity materials enter the silo and are broken up by the arch breaker 1. They then pass through the twin-screw feeder 2 below the silo and enter the KJG-35 paddle dryer 3 for drying (intermediate material contact heat exchange stage). The drying process is as follows: The material is continuously fed quantitatively into the feed port of the paddle dryer 3 by the twin-screw feeder 2. Inside the paddle dryer 3, one paddle shaft rotates driven by a motor chain. This rotating paddle shaft drives the other paddle shaft through gear meshing. Driven by the paddles, the material moves toward the other end while being heated and dried by the paddles and housing until it reaches the discharge end. The paddle dryer 3 features dual-shaft, hollow, wedge-shaped blades, internally ventilated with steam. Rotary joints for steam inlet and outlet are installed at the ends of the shafts. The two paddle shafts within the dryer are staggered, and the inner shell is shaped like a "W." A gap is left between the paddles and the inner shell, creating a hollow jacket between the inner and outer shells. Steam is introduced to heat the material. The steam pressure is controlled within 0.8 MPa, and the operating temperature of the equipment is below 180°C. After the paddles dry the material, it becomes a dry powder, with the moisture content reduced from 60% to below 10%.

[0084] The powdered dry material produced at the discharge end of the paddle dryer 3 falls onto the scraper of the scraper elevator 4. The scraper elevator 4 then carries the powdered material from bottom to top into the mixer 5 at the top. The powdered dry material and high-viscosity material (wet material) are added to the barrel of the mixer 5 at a mass ratio of 4:1. After the dry and wet materials are evenly mixed, the mixture has a moisture content of 20%-25%. It is then added to the hopper of the extrusion granulator 6 (DJY-180 model). The mixture enters the machine cavity through the feeding port at the bottom of the hopper. Under the action of the rotating screw, it is compacted, mixed, and propelled toward the die head. Finally, it is extruded through the discharge orifice at the die head to form elongated granular material with a diameter of 10 mm and a length of 20 mm-40 mm. The long granular material naturally falls onto the feeding belt of the BL-1200 swing material distributor 7. Under the combined action of the belt conveyor and the left and right swing of the swing motor, the material is evenly laid on the mesh belt at the feeding end of the belt dryer 8.

[0085] The belt dryer 8 (DW-1.5x8 mesh belt dryer 8) features a single-layer conveyor belt (mesh belt) inside. Long, granular materials are evenly laid onto the mesh belt and then moved in a single direction to dry. The belt dryer 8 utilizes steam heating and houses four drying units, each equipped with a hot air circulation fan and a steam heat exchanger. Circulating hot air and fresh air enter the belt dryer through a side duct and then pass from bottom to top through the mesh belt and the materials on it, forming a left-right cross-circulation system. A moisture outlet is located on the side of the belt dryer 8, allowing some moisture to be discharged from the side. After belt drying, the moisture content of the long, granular materials is reduced from 25% to below 8%. The dried, long, granular materials naturally fall into the hopper 14 below the discharge end of the belt dryer 8.

[0086] Optionally, the material drying tail gas from the top exhaust port of the paddle dryer 3 and the belt dryer 8 enters the first exhaust pipe 10, the tail gas of the exhaust pipe passes through the spray tower 11, the dust particles in the tail gas are separated by the centrifugal force, are thrown to the inner wall of the cylinder of the spray tower 11, are adsorbed by the water film layer flowing on the inner wall of the cylinder, flow to the bottom and are discharged through the dust discharge port, and the tail gas from the top of the cylinder of the spray tower 11 enters the second exhaust pipe 13 and then enters the exhaust fan 9.

[0087] The material drying tail gas from the top exhaust port of the paddle dryer 3 and the belt dryer 8 enters the exhaust pipe, the tail gas of the exhaust pipe passes through the spray tower 11, is introduced from the lower part of the cylinder in the tangential direction, rotates upward, the dust particles in the tail gas are separated by the centrifugal force, are thrown to the inner wall of the cylinder, are adsorbed by the water film layer flowing on the inner wall of the cylinder, flow to the bottom cone with the water flow, and are discharged through the dust discharge port. The tail gas from the top of the cylinder of the spray tower 11 enters the exhaust pipe and then enters the exhaust fan 9, a manual butterfly valve is arranged at the inlet of the fan to control the exhaust amount, and finally the tail gas is discharged through the external chimney under the action of the fan.

[0088] When the steam drying operation of the copper smelting intermediate material (wet slag) is performed by using the present application, first, the low-viscosity intermediate material is dried by the paddle dryer 3 through contact heat exchange, and powder-shaped intermediate material is obtained as dry material; the high-viscosity intermediate material is used as wet material, and the dry material and the wet material are simultaneously mixed by the spiral conveyor and then enter the mixing blender 5; the mixed material is lifted to the screw extrusion granulator 6 by the scraper elevator 4, and long strip-shaped granular material with a diameter of 8-10 mm is produced; the long strip-shaped granular material after granulation is uniformly laid on the mesh belt of the belt dryer 8 by the swing distributor 7; the mesh belt dryer 8 uses steam to heat the internal air, and each drying unit is provided with a hot air circulating fan. The circulating hot air and fresh air enter the inside of the belt machine from one side air duct and then pass through the mesh belt from bottom to top, that is, the material on the mesh belt, to form left-right cross circulation, and the wet exhaust port is arranged on the side of the belt machine, part of the moisture is discharged from the side, and long strip-shaped granular material with water content of less than 8% is produced, and the tail gas of the paddle dryer 3 and the mesh belt dryer 8 is collected and transmitted to the spray tower 11 for treatment and then discharged by the exhaust fan 9, and the long strip-shaped material after drying is collected in the hopper 14 and then is transported to the converter by the forklift for pyrometallurgical treatment.

[0089] The low-viscosity intermediate material of the copper smelting intermediate material is first dried by the paddle dryer 3, then is mixed with the high-viscosity intermediate material, and then sequentially passes through the wet granulation and steam drying to obtain granular material, and finally is directly fed into the converter for treatment, so that the drying kiln, the steam dryer and the flash furnace are not dried and treated, thereby improving the reaction conditions of the drying kiln, the steam dryer and the flash furnace, effectively relieving the situations such as the adhesion and corrosion of the steam dryer coil, improving the heat exchange efficiency, effectively prolonging the service life of the drying kiln, the steam dryer and the flash furnace boiler pipe, and improving the operation stability of the key core equipment and facilities.

[0090] While certain embodiments of the application have been described herein in detail, those skilled in the art will appreciate that modifications can be made of the above embodiments without departing from the scope and spirit of the application. The scope of the application is defined by the appended claims.

Claims

1. A steam drying system for copper smelting intermediate materials, characterized in that: include: Arch breaker, double screw feeder, paddle dryer, scraper elevator, mixer, extrusion granulator, material distributor, belt dryer, spray tower, among which, The arch breaker is located above the double-screw feeder, and the discharge end of the arch breaker is connected to the feed end of the double-screw feeder. The arch breaker is used to prevent the copper smelting intermediate material from arching and accumulating; The double-screw feeder is located below the arch breaker, and the discharge end of the double-screw feeder is connected to the feed end of the paddle dryer; The paddle dryer includes a main shaft and paddles, and steam is passed through the paddle dryer. The discharge end of the paddle dryer is located above the scraper elevator and is connected to the feed end of the scraper elevator. The scraper chain of the scraper elevator is set at an inclination angle of 40°-65°. The discharge end of the scraper elevator is connected to the feed end of the mixing mixer; The mixing and stirring machine is located above the extrusion granulator, and the discharge end of the mixing and stirring machine is communicated with the feed end of the extrusion granulator; The extrusion granulator is located above the material distributor, and the discharge end of the extrusion granulator is connected to the feed end of the material distributor; The discharging end of the material distributing machine is connected to the feeding end of the belt dryer; The belt dryer is steam-heated and includes at least four drying units, each of which has a mesh belt. Each drying unit is equipped with a hot air circulation fan and a steam heat exchanger. Circulating hot air and fresh air enter the drying unit and pass through the mesh belt and the material on the mesh belt from bottom to top, forming a left-right cross circulation. A moisture outlet is provided on the side of the belt dryer, and moisture is discharged from the moisture outlet. A hopper is provided below the discharge end of the belt dryer; The paddle dryer and the belt dryer are both provided with an exhaust port at the top, and the exhaust port is connected to one end of a first smoke exhaust pipe. The air inlet of the spray tower is located at the bottom, and the other end of the first smoke exhaust pipe is connected to the air inlet of the spray tower. The top of the spray tower is connected to one end of a second smoke exhaust pipe, and the other end of the second smoke exhaust pipe is connected to a smoke exhaust fan.

2. The steam drying system for copper smelting intermediate materials according to claim 1, characterized in that: A butterfly valve is installed at the inlet of the smoke exhaust fan to control the amount of smoke exhaust.

3. The steam drying system for copper smelting intermediate materials according to claim 1, characterized in that: The blades of the paddle dryer are double-shaft, wedge-shaped hollow blades.

4. A method for steam drying of copper smelting intermediate materials, characterized in that: The steam drying system for copper smelting intermediate materials according to claims 1 to 3 is applied, and the copper smelting intermediate materials include high-viscosity materials and low-viscosity materials, wherein the high-viscosity material is wet slag that adheres to the main shaft and blades of the paddle dryer at a drying temperature of 110°C to 120°C, and the low-viscosity material is wet slag that does not adhere to the main shaft and blades of the paddle dryer at a drying temperature of 110°C to 120°C, and the steam drying method includes: The low-viscosity material enters the silo and is broken up by the arch breaker. The low-viscosity material then enters the double-screw feeder below the arch breaker. The double-screw feeder feeds the broken-up low-viscosity material into the paddle dryer. The dispersed low-viscosity material is dried in the paddle dryer, the steam pressure is controlled within 0.8 MPa, and the operating temperature is less than 180° C. After being dried in the paddle dryer, the low-viscosity material becomes a powdered dry material, and the moisture content is reduced to less than 10%; The powdered dry material produced at the discharge end of the paddle dryer falls onto the scraper of the scraper elevator, and the scraper elevator brings the powdered dry material from bottom to top into the mixing mixer; Add the powdered dry material and the high-viscosity material into the mixing mixer, wherein the mass ratio of the powdered dry material to the high-viscosity material is 4:1, and after uniform mixing, the moisture content of the mixed material is 20% to 25%; The mixed material is added into the extrusion granulator to form a long strip granular material, wherein the long strip granular material has a diameter of 10 mm and a length of 20 mm to 40 mm. The long strip granular material falls onto the feed belt of the distribution machine, passes through the feed belt of the distribution machine, and enters the mesh belt of the belt dryer. After being dried by the belt dryer, the moisture content of the long strip granular material is reduced to below 8%, and then falls into the hopper below the discharge end of the belt dryer.

5. The method for steam drying of copper smelting intermediate materials according to claim 4, characterized in that: It also includes: the exhaust gas from material drying enters the first smoke exhaust pipe from the top exhaust ports of the paddle dryer and the belt dryer, the exhaust gas from the smoke exhaust pipe passes through the spray tower, and the dust particles in the exhaust gas are separated by centrifugal force and thrown to the inner wall of the cylinder of the spray tower, and are adsorbed by the water film layer flowing on the inner wall of the cylinder, flow to the bottom and are discharged through the dust exhaust port, and the exhaust gas coming out from the top of the cylinder of the spray tower enters the second smoke exhaust pipe and then leads to the smoke exhaust fan.

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