CN116793066A - A complete set of equipment for carbothermal reduction reaction - Google Patents

Abstract

A complete set of equipment for carbothermal reduction reaction, used to produce vanadium-nitrogen alloy, ferrovanadium nitride, reduced iron, ferrochromium nitride and other products. It includes a double-roller briquetting machine and a direct-heated rotary kiln. Part or all of the hemispherical nest mold on the roller of the ball press is made of elastic material. The direct heating rotary kiln includes a rotary tube, refractory material inside the rotary tube, kiln head box, kiln tail box and other components. The cylindrical or prismatic inner cavity surrounded by refractory materials is the kiln chamber. The kiln chamber is divided into preheating section, heating section and cooling section. Positive and negative electrodes are provided at both ends of the heating section. There are protrusions with a height of more than 1cm on the inner wall of the kiln chamber. The invention has the advantages of increasing the filling rate of materials inside the kiln chamber, reducing the voltage of the heating power supply, increasing the production capacity of the direct heating rotary kiln, and reducing energy consumption.

Description

A complete set of equipment for carbothermal reduction reaction

Technical field

The invention relates to a complete set of equipment for high-temperature carbothermal reduction reaction and belongs to the technical field of high-temperature equipment.

Background technique

The rotary kiln is an important heating and calcining equipment in the chemical, material, and even pharmaceutical industries, and is widely used. The Chinese patent CN112880389A submitted by the inventor discloses a direct-heated rotary kiln for carbothermal reduction reaction, which feeds power directly into the heated solid material in the rotary kiln through electrodes (that is, the rotary kiln). The material to be processed (hereinafter referred to as the material), the electric current flows from the heating power supply through the material through the positive electrode, returns to the negative electrode and then returns to the heating power supply, using the resistance of the material to make the material itself directly heat the electric heating rotary kiln (hereinafter referred to as the direct heating rotary kiln) . The materials in the kiln chamber (the approximately cylindrical inner cavity formed by the refractory material close to the inner wall of the rotary tube, that is, the place where the materials in the rotary tube can reach) generally rotate and/or tumble with the rotation of the rotary tube, and due to the rotation The rotary tube of the kiln generally has an inclination angle with the horizontal plane, and the material will also advance along the axis of the rotary tube during the rotation process, that is, the material in the rotary kiln advances in a spiral. The rotary kiln chamber is divided into preheating section (or heating section), heating section (or high temperature section), and cooling section (or cooling section) along the axial direction of the rotary tube. The materials pass through the preheating section, heating section, and cooling section in sequence. Then leave the kiln. Generally speaking, during the manufacturing process of the rotary kiln, the distance between the positive and negative electrodes inside the rotary tube has been fixed, which means that the distance between the positive and negative electrodes has been fixed, and further the heating section material used as the heating resistor has been fixed. length. The cross-sectional area of the material in the heating section will increase as the filling rate of the material in the kiln increases (the filling rate of the rotary kiln is generally defined as the ratio of the volume of the material in the rotary kiln to the volume of the rotary kiln), which improves the direct heating rotary kiln. The filling rate of the kiln, or increasing the filling rate of the heating section, can increase the production capacity of the direct-heated rotary kiln (ie, the output per unit time).

In general non-directly heated rotary kilns, due to heat transfer limitations, the material filling rate, especially the filling rate in the heating section, is rarely greater than 20%. As a direct-heating rotary kiln, the material in the kiln chamber directly heats itself, eliminating the process of heat transfer to the material from the inner wall of the rotary tube or the atmosphere in the kiln chamber. It can increase the material filling rate in the heating section while maintaining an increase in material flow rate, and improve Rotary kiln production capacity reduces the energy consumption per unit product (because no matter the production capacity is large or small, as long as the temperature is the same, the heat dissipation of the same rotary kiln to the surrounding environment through the rotary tube is basically certain. If the production capacity is large, the heat loss shared by the unit product will be Small), of course it also improves production efficiency. Generally, during the operation of a direct-heated rotary kiln, the filling rate is controlled at more than 25%, preferably around 50%. For materials with good fluidity and not serious caking, it can be controlled at 70% or even higher, improving The equipment production capacity is at least doubled.

Although the original intention of the inventor to study the direct-heated rotary kiln was to produce vanadium nitride or vanadium-nitrogen alloy with lower energy consumption and higher efficiency, after improvements in recent years and contact with other raw materials and products, he discovered that different carbon heat The reduction reaction is a reaction in which metal oxides and carbonaceous reducing agents are generally used for high-temperature heating reduction and/or nitridation. They all have a common characteristic. During the reaction process, a large amount of oxygen and carbon in the solid raw materials generate carbon monoxide gas. Due to the reduction in mass and the subsequent increase in density due to high temperature shrinkage, the volume is often reduced by half or even three-quarters or more. When a direct-heated rotary kiln is used as the reactor for the carbothermal reduction reaction, after the rotary kiln is installed, its kiln chamber structure, that is, the kiln type, is also fixed immediately. The inclination of the rotary tube (the angle between the axis of the rotary tube and the horizontal plane) ) is also fixed at the same time, and its influence on the forward speed of the material in it is also fixed. Under the influence of two factors, the volume of the material is greatly reduced during the reaction process and the rotary kiln type and slope are fixed. The material whose volume has not been reduced (hereinafter referred to as the left-end material) and the material whose volume has decreased (hereinafter referred to as the right-end material) ) are almost the same, the flow rate control step must be the volumetric flow rate of the material at the left end. That is to say, even if the volume flow rate of the material at the left end is greater than the volume flow rate of the material at the right end, the volume flow rate of the material at the left end cannot meet the volume flow rate requirement of the material at the right end. This results in a significant reduction in the filling rate of the kiln section where the material at the right end is located.

In actual production practice, since the above-mentioned right-end material has experienced high-temperature shrinkage and longer movement in the rotary kiln, it is smoother and denser than the left-end material, which is more conducive to increasing its volumetric flow rate. In addition, the temperature of the heating section of the direct-heated rotary kiln is relatively high, generally above 1000°C. Volatile components at high temperatures will flow with the gas phase to the preheating section. As the temperature decreases, they will be deposited in a certain section of the preheating section. The formation of loops is a common phenomenon in rotary kilns, and the loops will further reduce the volumetric flow rate of the material at the left end.

Therefore, the flow rate of the above-mentioned left-end materials in the carbothermal reduction reaction becomes a restrictive control factor that hinders the filling rate of materials in the kiln, especially the filling rate of the heating section, and is a flow rate bottleneck. This greatly reduces the material filling rate of the direct-heated rotary kiln, limits the length of the preheating section of the rotary kiln (the longer the preheating section, the greater the resistance to material flow), reduces its equipment capacity, and increases the control requirements. Fill rate difficulties. Although the inventor adopted a variety of technical solutions in the CN112880389A patent application to improve the filling rate of the heating section material and the forward speed of the left end material in the direct-heated rotary kiln, it also encountered control difficulties. It was difficult to balance the material flow rate and filling rate. It is necessary to study and adjust various structural parameters of direct-heated rotary kilns for different materials and different volume shrinkage ratios.

Using a direct-heated rotary kiln to carry out carbothermal reduction reaction and briquetting the solid raw materials is beneficial to improving the conductivity of the solid raw materials, improving the heat and mass transfer process during the reaction, and increasing the forward speed of the materials in the rotary kiln chamber. However, various existing briquetting machines or other types of pelletizing machines have their own shortcomings.

In commonly used pelletizing machines, powdered raw materials need to be continuously rolled during the pelletizing process, and the density of metal oxides is often greater than that of carbonaceous reducing agents. During the rolling process of the powdered materials, the two are easily separated. And its ball strength is relatively low. Of course, its advantages are that the formed balls have better roundness and the equipment has high production capacity.

Isostatic pressing or quasi-isostatic briquetting machines use large operating pressure to form pellets with high strength. However, the equipment is expensive, has small production capacity, and has complicated operating procedures, and cannot meet the requirements of carbothermal reduction reaction.

Roller briquetting machines are widely used due to their large production capacity, high degree of automation, simple operation, and low equipment prices. However, due to the difficulty of demoulding, the depth of the hemispherical sockets on the pair of roller molds or the ratio of the depth and width of the hemispherical sockets is limited. If the hemispherical sockets are too deep, it will be difficult to demould. Therefore, the depth of the ball socket is generally made relatively shallow, and the roundness of the extruded ball is very poor, even close to a round cake shape or a double quadrangular pyramid shape. The repose angle of the material pile of such shaped balls is relatively large, making it difficult to flow in the rotary kiln and the forward speed is low.

As far as the inventor knows, there is no briquetting machine with low equipment price, large production capacity, good roundness of the formed balls, high strength of the formed balls, high degree of automation and simple operating procedures.

To sum up, although the direct-heated rotary kiln has huge advantages for carbothermal reduction reactions, only the improvement of the direct-heated rotary kiln can improve the filling rate of materials in the kiln chamber and increase the volumetric flow rate of the materials. It is very difficult and needs to be combined with the improvement of the briquetting machine to achieve the purpose of increasing the filling rate and increasing the material volume flow rate.

Contents of the invention

The purpose of the invention is to increase the volumetric flow rate of the aforementioned left-end materials in the high kiln chamber of a direct-heated rotary kiln, take into account a sufficiently high filling rate of solid materials in the kiln chamber, and increase the volumetric flow rate of all solid materials in the kiln chamber during carbothermal reduction. Reduce the rotation speed of the rotary tube when the rotary kiln is running, and adapt to the different volume shrinkage rates of different raw materials in different carbothermal reduction reactions; on the premise of increasing the volume flow rate of the material at the left end, a preheating section is set up in the direct-heated rotary kiln chamber. Or extend the length of the preheating section; through the above purposes, we can ultimately further improve the electric heating efficiency of the direct-heated rotary kiln, simplify the adjustment of the rotary kiln structural parameters, simplify the difficulty of rotary kiln operation control, improve the operation stability of the rotary kiln, and increase equipment productivity. Reduce dust generation.

The purpose of the present invention is achieved as follows: on the basis of summarizing the inventor's previous experience in manufacturing and using a direct-heated rotary kiln for carbothermal reduction reactions, the present invention improves the roller briquetting machine in the carbothermal reduction device. , improves the roundness of the formed raw material balls, reduces the difficulty of adjusting various structural parameters of the direct-heated rotary kiln, and improves its operational stability.

The specific technical solutions of the present invention are as follows:

A complete set of equipment for carbothermal reduction reaction, which includes a counter-roller briquetting machine and a direct-heated rotary kiln. It is characterized in that part or all of the hemispherical nest molds on the rollers of the counter-roller briquetting machine are made of elastic materials. Since the elastic material is used in the hemispherical cavity mold part of the roll mold, the hemispherical cavity can be made deeper, and when the ball is pressed, the elastic material at the bottom of the hemispherical cavity deforms and expands and becomes thinner under the action of pressure, so that the depth of the hemispherical cavity is further increased, so that The roundness of the pressed balls is improved. When the pressure disappears, the elastic material rebounds and naturally releases the pressed ball from the mold and pops out of the ball socket, which is beneficial to the release of the ball.

The direct heating rotary kiln includes a rotary tube, refractory material inside the rotary tube, a kiln head box and a kiln tail box; the long inner cavity surrounded by the refractory material is the kiln chamber; the kiln chamber is divided into a preheating section, Heating section and cooling section; positive and negative electrodes are provided at both ends of the heating section. The heating power supply is externally connected to the positive and negative electrodes. The electrodes are in contact with the heated material inside the rotary kiln. The current flows through the material through the positive electrode and then to the negative electrode. , so that the material itself acts as a resistor to heat up to complete the heating of the material; a protrusion with a height of more than 1cm is provided on the inner wall of the kiln chamber; the rotary tube is rotationally sealed and connected to the kiln head box and kiln tail box; in the kiln The tail box is provided with an air inlet. The protrusions on the inner wall of the kiln chamber are generally made of refractory materials, and the protrusions form the frying tank and/or the retaining ring. When the roundness of the raw material balls is improved, the stir-frying trough not only has the function of raising the height of the raw material balls in the kiln chamber and increasing the filling rate, but also has the function of stir-frying the raw material ball pile and preventing the overall sliding of the raw material ball pile. . The retaining ring can reduce the effective inner diameter of the kiln chamber and increase the filling rate of materials between it and the kiln chamber feed port.

After the solid raw materials for the carbothermal reduction reaction are pelletized by the double-roller briquette machine, they enter the kiln chamber through the kiln head box of the direct-heated rotary kiln, pass through the preheating section, heating section and cooling section in sequence, and then exit from the kiln. The discharge port of the chamber falls into the kiln tail box for temporary storage. Since the roundness of the raw material ball is improved, setting up a preheating section or lengthening the length of the preheating section will have little impact on the volumetric flow rate of the material at the left end. After the material passes through the preheating section, the temperature rises and is partially reduced, achieving better electrical conductivity.

The gaseous raw material or protective gas for the carbothermal reduction reaction enters the kiln tail box from the air inlet on the kiln tail box, and then exits the kiln chamber through the cooling section, heating section and preheating section.

Further, the elastic material is rubber or preferably polyurethane rubber.

Further, a baffle plate is provided at the discharge port of the kiln chamber; after the solid raw material of the carbothermal reduction reaction is pelletized by the double-roller briquetting machine, it passes through the kiln head box of the direct-heated rotary kiln. It enters the kiln chamber, passes through the preheating section, heating section and cooling section in sequence, then crosses the baffle plate from the kiln discharge port and falls into the kiln tail box for temporary storage. Set a baffle plate at the kiln discharge port to reduce the effective inner diameter of the kiln discharge port, making this place a bottleneck for the solid material volume flow rate, so that the volume flow rate of the aforementioned left end material can keep up with the volume flow rate requirement of the right end material. . Further, while maintaining or reducing the rotation speed of the rotary tube, the filling rate of materials in the kiln chamber of the direct-heated rotary kiln reaches the required height.

Further, the heating power supply is an adjustable DC power supply, its maximum output voltage is Umax volts, and its maximum output current is Imax amperes; the voltage value U1 is between 0 ~ Umax volts, and the current value I1 is between 0 ~ Imax between amperes; when the direct heating rotary kiln is working, the output of the heating power supply can be switched between two voltage and current ranges while keeping the installed power unchanged; the two voltage and current ranges are high voltage and high voltage respectively. Low current gear and low voltage and high current gear; in the high voltage and low current gear, the output voltage is adjustable from 0 to Umax volts, and the output current is adjustable from 0 to I1 amps; in the low voltage and high current gear, the output The adjustable voltage range is 0 ~ U1 volts, and the output current adjustable range is 0 ~ Imax amps.

There are one or more thermocouples in the kiln heating section, which pass through the rotary tube in the radial direction and are inserted into the refractory material or pass through the refractory material and close to the kiln wall; the temperature measured by the thermocouples The data analog quantity is wirelessly transmitted to the control cabinet of the heating power supply after analog-to-digital conversion by a temperature transmitter fixed on the outer circumferential surface of the rotary tube for temperature display and control of the heating power supply output power.

Furthermore, the complete set of equipment of the present invention is used as a complete set of equipment for high-temperature carbothermal reduction reaction and/or high-temperature nitriding reaction. The reaction includes the following reaction process:

R1. Carbothermal reduction and nitridation of vanadium oxide and carbonaceous reducing agent under high temperature and nitrogen atmosphere to produce vanadium-nitrogen alloy;

R2. Carbothermal reduction and nitridation of vanadium oxide, iron and/or iron oxide and carbonaceous reducing agent under high temperature and nitrogen atmosphere to produce iron vanadium nitride;

R3. Reaction of iron oxide and/or iron ore and carbonaceous reducing agent and/or hydrogen at high temperature and in isolation from air to produce reduced iron, sponge iron, iron nitride or iron-carbon compounds or mixtures;

R4: Carbothermal reduction and nitridation of chromium oxide and carbonaceous reducing agent under high temperature and nitrogen atmosphere to produce chromium nitride and/or chromium carbide;

R5: Carbothermal reduction and nitridation of high carbon ferrochromium and chromium oxide and/or iron oxide under high temperature and nitrogen atmosphere to produce microcarbon ferrochromium nitride;

R6: Carbothermal reduction and nitridation of titanium oxide compounds under high temperature and nitrogen atmosphere to produce titanium carbonitride;

R7: Use petroleum coke and/or asphalt to carbonize and/or graphitize at high temperatures to produce secondary battery electrode graphite;

R8: Carbothermal reduction of silicon dioxide and carbonaceous reducing agent at high temperature to produce metallic silicon and silicon carbide or in nitrogen atmosphere to produce silicon nitride and/or silicon carbonitride.

R9: Titanium carbonitride material is prepared by carbothermal reduction of titanium oxide, aluminum oxide and carbonaceous reducing agent at high temperature, which is a type of MAX phase material.

Compared with the existing technology, the technical solution of the present invention has the following advantages:

1) By replacing part or all of the hemispherical nest mold on the roller of the ball press with elastic material, a raw material ball with a higher roundness can be obtained, and the ball can be easily demoulded during ball pressing, and at the same time maintain the alignment. The production capacity, degree of automation and operational stability of the roller ball machine.

2) By replacing part or all of the hemispherical nest mold on the roll of the double-roller ball press with an elastic material, raw material balls with higher roundness can be obtained. In the carbothermal reduction reaction, even when the volume of the material is greatly reduced during the reaction, it increases the volumetric flow rate of the raw material balls in the direct-heated rotary kiln chamber, so that the volumetric flow rate of the aforementioned left-end material can keep up with the right-end material. Volumetric flow rate needs. It improves the filling rate of materials in the kiln chamber and allows the rotary tube to operate at a lower speed.

3) Due to the improved roundness of the raw material balls, when the kiln preheating section is ringed, the raw material balls can maintain sufficient volume flow rate at the ringed place to meet the aforementioned requirements for the material volume flow rate at the right end. The stability of the rotary kiln operation is maintained and the maintenance interval of the rotary kiln is extended.

4) Due to the improvement of the roundness of the raw material ball, the volume flow rate of the material at the left end is increased, causing the volume flow rate bottleneck of the overall material to move to the baffle ring or baffle plate, thus simplifying the control of the filling rate of the material in the kiln chamber. , Simplifying the corresponding relationship between the rotary tube rotation speed and the solid material volume flow rate at the kiln discharge port. When the heating capacity is sufficient and the minimum reaction time requirements are maintained, the rotation speed of the rotary tube can be conveniently used to control the output of the rotary kiln.

5) Due to the improved roundness of the raw material ball, the rotary tube can provide sufficient volume flow rate of solid materials at a lower speed, thus reducing the wear of the material, reducing the generation and dust emission in the kiln chamber, and reducing Reduce the pressure of dust recovery and dust control.

6) Due to the improvement of the roundness of the raw material ball, the volume flow rate of the material at the left end is increased. The longer length of the kiln preheating section has less impact on the volume flow rate of the material at the left end. A longer preheating section length can be set to improve the The heat exchange effect of the preheating section reduces the temperature of the gas exiting the preheating section, increases the temperature of the solid materials entering the heating section from the preheating section, and increases the pre-reduction degree of the solid materials entering the heating section.

7) Due to the improvement of the roundness of the raw material ball, the volume flow rate of the material at the left end is increased, which can reduce the inclination rate of the rotary tube and improve the operation safety and life of the rotary kiln.

8) Due to the improvement of the roundness of the raw material ball, the edges and corners of the raw material ball are reduced, the wear rate of the edges and corners of the raw material ball in the kiln chamber is reduced, and the proportion of fine-grained materials is reduced. For products requiring larger particle size, the proportion of returned fine-grained materials is reduced and production efficiency is improved.

9) Due to the improvement of the roundness of raw material balls, it has become relatively simple to adjust the rotary kiln structural parameters, kiln material filling rate, rotary tube speed, and material inlet and outlet speed, making it possible to manufacture larger-scale direct-heated rotary kiln for carbothermal reduction reaction. Kiln, expanding the scale of production has become relatively simple technically.

The technical solution of the present invention is used to carry out the carbothermal reduction reaction, the production is stable and reliable, the output of the carbothermal reduction reaction is improved, the process is environmentally friendly, efficient, energy-saving, highly automated, and the production cost and labor intensity are reduced. .

Description of the drawings

Figure 1 is a schematic diagram of a direct-heated rotary kiln in Embodiment 1.

Figure 2 is a schematic front view of the rotary tube of the direct-heated rotary kiln in Embodiment 1 from the discharge end to the feed end, with the upper left part partially sectioned.

Figure 3 is a schematic diagram of the ball socket mold of the pair of roller ball presses in Embodiment 1.

Example 1

Figures 1 and 2 are schematic diagrams of Embodiment 1. As shown in Figure 1, the direct-heated rotary kiln is used as a reactor for carbothermal reduction and/or nitridation reactions of raw materials such as metal oxides, and includes a kiln head box 1, a kiln head box tail gas outlet 16, a drive Wheel 2, load-bearing wheel 3, a set of two positive electrodes 14, a rotary tube 5, a refractory material 6, a set of two negative poles 15, 6 K-grading thermocouples 12, the rotational sealing connection between the kiln tail box and the rotary tube 8. Kiln tail box 9 and air inlet 13 on the kiln tail box. Refractory material 6 plays the role of fire resistance, heat preservation and insulation at the same time. It is required that the resistance of the refractory material in contact with the heating section and the material is greater than that of the material. An approximately circular inner cavity surrounded by the refractory material 6 and approximately the same length as the rotary tube is called the kiln chamber 17 . The kiln chamber 17 is divided into the kiln chamber inlet 171, the preheating section 172, the heating section 173, the cooling section 174, and the kiln chamber outlet 175 according to the order in which the materials pass through. The remaining details are not shown.

As shown in Figure 2, the refractory material 6 of the direct heating rotary kiln is composed of high and low specifications of refractory material 602 and 601. In the radial direction of the rotary tube, the refractory material 602 protrudes more into the kiln chamber than the refractory material 601, with a protruding height of 3cm, forming a frying trough. When the rotary kiln rotates, it can prevent the material from sliding on the kiln wall and raise the material level. A baffle plate 19 is provided at the discharge port of the kiln chamber, or a section of screen tube 25 is connected to the discharge port of the kiln chamber, and a baffle plate 19 is provided at the discharge port of the screen tube. The angle between the upper right edge of the baffle plate 19 in Figure 2 and the horizontal plane is set to 20°. It can also be seen from Figure 2 that the annular negative electrode 15 is higher than the surrounding refractory materials 601 and 602 in the direction facing the central axis of the rotary tube, forming a retaining ring.

The schematic cross-sectional view of the ball socket mold of the double-roller ball press is shown in Figure 3. Sub-picture B is a partial enlarged view of sub-picture A. The roll steel mold 1 is a circular ring structure with a series of hemispherical sockets arranged regularly on the outer cylindrical surface. The shaft that drives the steel mold to rotate fits into its inner circle. There is a mold 2 made of polyurethane rubber inside the hemispheric socket. Mold 2 covers the bottom of the hemispherical socket of steel mold 1 and forms part of the hemispherical socket mold. A double-roller briquetting machine has two steel molds 1, whose rotation axes are arranged parallel and side by side on the horizontal plane, their cylindrical surfaces are separated from each other by 0 to several millimeters, and the hemispheric socket opening surface of one steel mold is aligned with the other steel mold. The open surface of the hemispheric fossa. Two opposing hemispheric sockets form an approximate spherical shape. The two hemispherical sockets that are about to face each other will cut the solid material above them into the hemispherical sockets with the downward rotation of the rollers, and the extrusion process will be completed when the two hemispherical sockets are facing each other. At this time, the thicker rubber at the bottom of the hemispheric socket will extend to the thinner parts around it, making the bottom of the hemispheric socket deeper, and the solid material surrounded by the two hemispheric sockets will be approximately spherical. As the pair of rollers continue to rotate downward, the pressure gradually disappears, the rubber rebounds and the ball is ejected, completing the ball pressing process.

The raw material balls obtained by pressing are nearly spherical and have good roundness. The long diameter of a single raw material ball is ~4.0cm and the short diameter is ~3.5cm. The repose angle of the raw material pellet pile is less than 15°. The wall of the direct heating rotary kiln has a frying tank with a depth of ~3cm formed by refractory protrusions. When the rotation speed of the rotary tube is 0.2 rpm, the angle between the slope of the pile of raw material balls in the kiln and the horizontal plane is less than 20°.

For comparison, the shape of the raw material balls pressed by the existing double-roller ball press is approximately a double square pyramid formed by two square pyramids with a square bottom joined together on one side of the square. The angle of repose of the raw material ball is >30°, around 35°. Under the same rotary kiln conditions mentioned above, the angle between the slope of the pile and the horizontal plane is approximately 40°.

Claims (7)

1. A complete set of equipment for carbothermal reduction reaction, which includes a double-roller briquetting machine and a direct-heated rotary kiln. It is characterized in that: part or all of the hemispherical nest molds on the rollers of the double-roller briquetting machine are elastic. Material; The direct heating rotary kiln includes a rotary tube, refractory material inside the rotary tube, a kiln head box and a kiln tail box; the long inner cavity surrounded by the refractory material is the kiln chamber; the kiln chamber is divided into a preheating section, Heating section and cooling section; positive and negative electrodes are provided at both ends of the heating section. The heating power supply is externally connected to the positive and negative electrodes. The electrodes are in contact with the heated material inside the rotary kiln. The current flows through the material through the positive electrode and then to the negative electrode. , so that the material itself acts as a resistor to heat up to complete the heating of the material; a protrusion with a height of more than 1cm is provided on the inner wall of the kiln chamber to form a frying trough or a blocking ring, or a frying trough and a blocking ring. ; The rotary tube is connected with the kiln head box and the kiln tail box in a rotary seal; an air inlet is provided on the kiln tail box; After the solid raw materials for the carbothermal reduction reaction are pelletized by the double-roller briquette machine, they enter the kiln chamber through the kiln head box of the direct-heated rotary kiln, pass through the preheating section, heating section and cooling section in sequence, and then exit from the kiln. The discharge port of the chamber falls into the kiln tail box; The gaseous raw material or protective gas for the carbothermal reduction reaction enters the kiln tail box from the air inlet on the kiln tail box, passes through the cooling section, heating section and preheating section of the kiln chamber in sequence, and then exits the kiln chamber. 2. A complete set of equipment for carbothermal reduction reaction according to claim 1, characterized in that: the elastic material is rubber. 3. A complete set of equipment for carbothermal reduction reaction according to claim 1, characterized in that: the elastic material is polyurethane rubber. 4. A complete set of equipment for carbothermal reduction reaction according to any one of claims 1 to 3, characterized in that: a baffle plate is provided at the discharge port of the kiln chamber; carbothermal reduction reaction After the solid raw materials are pelletized by the double-roller briquette machine, they enter the kiln chamber through the kiln head box of the direct-heated rotary kiln, pass through the preheating section, heating section and cooling section in sequence, and then exit the kiln chamber. After crossing the baffle, it falls into the kiln tail box for temporary storage. 5. A complete set of equipment for carbothermal reduction reaction according to any one of claims 1 to 4, characterized in that: the heating power supply is an adjustable DC power supply, and its maximum output voltage is Umax volts, The maximum output current is Imax amperes; the voltage value U1 is between 0 ~ Umax volts, and the current value I1 is between 0 ~ Imax amperes; when the direct heating rotary kiln is working, the heating power supply is required to maintain the installed power. Under the premise of changing, its output can be switched between two voltage and current ranges; the two voltage and current ranges are high voltage and low current range and low voltage and high current range; in the high voltage and low current range, the output voltage is adjustable range is 0 ~ Umax volts, the output current can be adjusted in the range of 0 ~ I1 amps; in the low voltage and high current range, the output voltage can be adjusted in the range of 0 ~ U1 volts, and the output current can be adjusted in the range of 0 ~ Imax amps. 6. A complete set of equipment for carbothermal reduction reaction according to any one of claims 1 to 4, characterized in that: there is one or more thermocouples in the heating section of the kiln, which rotate along the The tube passes through the rotary tube in the radial direction and is inserted into the refractory material or passes through the refractory material and is close to the kiln wall; the analog temperature data measured by the thermocouple is simulated by a temperature transmitter fixed on the outside of the circumferential surface of the rotary tube. After the data is converted, it is wirelessly transmitted to the control cabinet of the heating power supply for displaying the temperature and controlling the output power of the heating power supply. 7. A complete set of equipment for carbothermal reduction reaction according to any one of claims 1 to 4, characterized in that: it is used as a complete set of equipment for high-temperature carbothermal reduction reaction and/or high-temperature nitriding reaction, The reaction includes the following reaction process: R1. Carbothermal reduction and nitridation of vanadium oxide and carbonaceous reducing agent under high temperature and nitrogen atmosphere to produce vanadium-nitrogen alloy; R2. Carbothermal reduction and nitridation of vanadium oxide, iron and/or iron oxide and carbonaceous reducing agent under high temperature and nitrogen atmosphere to produce iron vanadium nitride; R3. Reaction of iron oxide and/or iron ore and carbonaceous reducing agent and/or hydrogen at high temperature and in isolation from air to produce reduced iron, sponge iron, iron nitride or iron-carbon compounds or mixtures; R4: Carbothermal reduction and nitridation of chromium oxide and carbonaceous reducing agent under high temperature and nitrogen atmosphere to produce chromium nitride and/or chromium carbide; R5: Carbothermal reduction and nitridation of high carbon ferrochromium and chromium oxide and/or iron oxide under high temperature and nitrogen atmosphere to produce microcarbon ferrochromium nitride; R6: Carbothermal reduction and nitridation of titanium oxide compounds under high temperature and nitrogen atmosphere to produce titanium carbonitride; R7: Use petroleum coke and/or asphalt to carbonize and/or graphitize at high temperatures to produce secondary battery electrode graphite; R8: Carbothermal reduction of silicon dioxide and carbonaceous reducing agent at high temperature to produce metallic silicon and silicon carbide or in nitrogen atmosphere to produce silicon nitride and/or silicon carbonitride; R9: Titanium carbonitride material is prepared by carbothermal reduction of titanium oxide, aluminum oxide and carbonaceous reducing agent at high temperature, which is a type of MAX phase material.