Preparation of ferrous sulfate monohydrate components based on two-stage high-temperature dehydration

Abstract

The utility model discloses a ferrous sulfate monohydrate preparation component based on two-stage high-temperature dehydration, comprising a drying drum and a combustion chamber, wherein the head of the drying drum is higher than the tail and can rotate, the drying drum is formed by connecting a first drying drum and a second drying drum, the tail of the first drying drum is connected to the head of the second drying drum by a connecting assembly and the connecting assembly cannot rotate, the combustion chamber comprises a first combustion chamber and a second combustion chamber, the first combustion chamber feeds high-temperature flue gas into the first drying drum through the connecting assembly, and the second combustion chamber is close to the tail of the second drying drum and feeds high-temperature flue gas into the second drying drum. The utility model feeds high-temperature flue gas into the two drying drums through two combustion chambers respectively, so as to facilitate segmented temperature control to achieve segmented dehydration of raw materials, obtain ferrous sulfate monohydrate with higher purity, and finally achieve the purpose of easy temperature control, high product purity and high production efficiency.

Description

Technical Field

[0001] The utility model relates to a ferrous sulfate monohydrate preparation component, in particular to a ferrous sulfate monohydrate preparation component based on two-stage high-temperature dehydration. Background Art

[0002] Titanium dioxide is one of the three major inorganic chemical products and is known as the "king of white pigments." Titanium dioxide has stable physical and chemical properties, excellent optical and electrical properties, and excellent pigment properties, so it has a wide range of uses.

[0003] Ferrous sulfate monohydrate, a by-product of titanium dioxide production by the sulfuric acid method, can be divided into two categories according to the entire production process: the first category is ferrous sulfate heptahydrate separated by frozen crystallization, which is converted into ferrous sulfate monohydrate by drying; the second category is the filtrate of hydrolyzed metatitanic acid. Due to the control of the iron-titanium ratio, the ferrous sulfate remaining in the waste acid is separated as ferrous sulfate monohydrate when the waste acid is concentrated, reused and reused.

[0004] Ferrous sulfate heptahydrate, also known as green vitriol, is an inorganic compound with a chemical formula of FeSO4·7H2O and a melting point of 64°C. It is the main byproduct of the sulfuric acid process for the production of titanium dioxide using ilmenite as raw material. However, the use of acid-soluble titanium slag as raw material reduces the amount of iron entering the production of titanium dioxide by removing most of the iron elements due to the smelting of titanium slag, with the aim of reducing the amount of ferrous sulfate heptahydrate byproducts and alleviating the pressure of oversupply of such products in the market. Depending on the source of the ore, the sulfuric acid process for the production of titanium dioxide using 1 ton of ilmenite raw material will produce 2.5 to 3.5 tons of ferrous sulfate heptahydrate. More than 90% of China's production facilities use ilmenite for production, so a large amount of ferrous sulfate heptahydrate will be produced, which is limited in direct market absorption and faces huge disposal and environmental problems.

[0005] Ferrous sulfate monohydrate is an inorganic compound with the chemical formula FeSO4·H2O and a melting point of 64°C. It is mainly used as trace elements in fertilizers, water treatment agents, concrete additives, and in the production of iron-based pigments. It has a wide range of uses. Therefore, using ferrous sulfate heptahydrate to produce ferrous sulfate monohydrate is an effective way to solve the problem that a large amount of ferrous sulfate heptahydrate is difficult to directly use and causes environmental problems.

[0006] In traditional equipment for drying ferrous sulfate heptahydrate to produce ferrous sulfate monohydrate, a drying drum is often used as a drying component, which has the problems of difficult to control drying temperature, low production efficiency and low product purity. The reasons are as follows: high-temperature flue gas is introduced from the end of the drying drum and discharged from the head end, so the temperature at the end of the drying drum is higher than the temperature at the head end. However, in the actual drying process, the raw material humidity in the head end of the drying drum is high, and a higher temperature is required for dehydration. The raw material itself has been partially dehydrated by the back end, so the required temperature is slightly lower. This is exactly the opposite of the temperature difference in the drying drum of traditional equipment. If the introduced flue gas temperature is too high, the water in the ferrous sulfate monohydrate will be completely removed and ferrous sulfate monohydrate will not be obtained. If the introduced flue gas temperature is not high enough, it will not only reduce the production efficiency, but also may produce ferrous sulfate dihydrate, ferrous sulfate trihydrate, etc., and high-purity ferrous sulfate monohydrate cannot be obtained. Utility Model Content

[0007] The purpose of the utility model is to provide a ferrous sulfate monohydrate preparation component based on two-stage high-temperature dehydration, which is easy to control temperature, has high product purity and high production efficiency, in order to solve the above problems.

[0008] The utility model achieves the above-mentioned purpose through the following technical solutions:

[0009] A ferrous sulfate monohydrate preparation component based on two-stage high-temperature dehydration, comprising a drying drum and a combustion chamber for providing high-temperature flue gas to the drying drum, wherein the head of the drying drum is higher than the tail and can rotate, and the drying drum is formed by connecting a first drying drum and a second drying drum, wherein the head of the first drying drum serves as the head of the drying drum, and the tail of the second drying drum serves as the tail of the drying drum, and the tail of the first drying drum is connected to the head of the second drying drum by a connecting component and the connecting component cannot rotate, and the combustion chamber comprises a first combustion chamber and a second combustion chamber, wherein the first combustion chamber supplies high-temperature flue gas into the first drying drum through the connecting component, and the second combustion chamber is close to the tail of the second drying drum and supplies high-temperature flue gas into the second drying drum.

[0010] Preferably, in order to facilitate the uniform delivery of the high-temperature flue gas from the first combustion chamber into the drying drum, the connecting assembly includes an annular outer connecting cylinder and an annular inner connecting cylinder, the outer connecting cylinder is mounted on the outside of the inner connecting cylinder, the circumferential inner wall of the outer connecting cylinder is provided with a concave ring formed by an inward concave, the circumferential outer wall of the outer connecting cylinder is provided with an interface communicating with the concave ring and the interface is connected to the high-temperature flue gas pipe of the first combustion chamber, a plurality of radially penetrating air intake holes are provided in the cylinder wall of the inner connecting cylinder along the circumferential direction, the outer ends of all the air intake holes are located in the concave ring, the inner ends of the air intake holes are communicated with the first drying drum and the second drying drum, the tail of the first drying drum and the head of the second drying drum are respectively located outside the axial ends of the inner connecting cylinder and are respectively butted against each other.

[0011] Preferably, in order to allow most of the high-temperature flue gas in the first combustion chamber to enter the first drying drum more quickly for high-temperature dehydration of the feed with high humidity, and at the same time to utilize part of the high-temperature flue gas in the first combustion chamber to push the raw materials passing through the inner connecting cylinder downward to avoid accumulation of raw materials, the multiple air intake holes in the middle and upper wall of the inner connecting cylinder are all ascending air intake holes, and a section of the ascending air intake holes close to the inner end is bent toward the first drying drum, and the multiple air intake holes in the lower wall of the inner connecting cylinder are all descending air intake holes, and a section of the descending air intake holes close to the inner end is bent toward the second drying drum.

[0012] Preferably, in order to facilitate processing and assembly, and at the same time to ensure a better sealing effect between the inner connecting cylinder and the two drying cylinders, the axial ends of the inner connecting cylinder are close to the outer circumferential edge positions and extend outwards to form limit rings, and the inner walls of the two limit rings are respectively in contact with the outer wall of the tail of the first drying cylinder and the outer wall of the head of the second drying cylinder, and the circumferential inner wall surface of the inner connecting cylinder, the circumferential inner wall surface of the first drying cylinder and the circumferential inner wall surface of the second drying cylinder are flush with each other, and annular ring bosses are respectively provided on the circumferential outer wall of the first drying cylinder near the tail and on the circumferential outer wall of the second drying cylinder near the head, the outer ends of the two limit rings are respectively close to the corresponding ends of the two annular bosses and a first sealing ring is installed in the gap, and the circumferential inner walls of the axial ends of the outer connecting cylinder are respectively provided with "L"-shaped annular grooves, and the corresponding ends of the two annular bosses are respectively placed in the two annular grooves.

[0013] Preferably, in order to achieve a better sealing effect, a second sealing ring is installed between the corresponding end of the annular boss and the groove wall of the corresponding annular groove of the external connecting tube.

[0014] Preferably, in order to further achieve a better sealing effect, the outer walls at both axial ends of the external connecting tube are respectively connected to one end of two groups of elastic sealing sheets, and the other ends of the two groups of elastic sealing sheets are respectively in contact with the outer walls of the two annular bosses.

[0015] Preferably, in order to perform more precise temperature control on the first drying drum and the second drying drum, a first temperature sensor is provided on the wall of the first drying drum, and a second temperature sensor is provided on the wall of the second drying drum, and the signal output end of the first temperature sensor and the signal output end of the second temperature sensor are respectively connected to the signal input end of the controller or respectively connected to the signal input end of the temperature display.

[0016] The beneficial effects of the utility model are:

[0017] The utility model improves a traditional drying drum into two drying drums and connects them through a non-rotatable connecting component, and respectively feeds high-temperature flue gas into the two drying drums through two combustion chambers, so that the temperature in the first drying drum close to the feed end is higher than the temperature in the second drying drum close to the discharge end, which meets the actual application requirements of dehydrating the feed end as quickly as possible through a higher temperature and requiring a slightly lower temperature at the discharge end, and is easy to implement segmented temperature control to achieve segmented dehydration of raw materials, so as to obtain ferrous sulfate monohydrate with higher purity, and finally achieves the purpose of easy temperature control, high product purity and high production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the main structure of the ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration of the utility model;

[0019] Figure 2 is a schematic diagram of the main cross-sectional structure of the connection assembly of the ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration of the present invention, and the ratio in the figure is greater than Figure 1 And the perspective is the same;

[0020] Figure 3 The left side view of the internal connection cylinder of the ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration of the present invention is shown in the figure. Figure 2 same. DETAILED DESCRIPTION

[0021] The utility model is further described below in conjunction with the accompanying drawings:

[0022] like Figure 1 - Figure 3As shown, the ferrous sulfate monohydrate preparation component based on two-stage high-temperature dehydration of the utility model includes a drying drum (refer to the first drying drum 4 and the second drying drum 10 described below) and a combustion chamber for providing high-temperature flue gas to the drying drum (refer to the first combustion chamber 7 and the second combustion chamber 12 described below), the head of the drying drum is higher than the tail and can rotate, the inclination of the drying drum is determined according to needs, generally at an angle of 3-5° with the horizontal direction, the drying drum is formed by connecting the first drying drum 4 and the second drying drum 10, the head of the first drying drum 4 serves as the head of the drying drum, the tail of the second drying drum 10 serves as the tail of the drying drum, the tail of the first drying drum 4 is connected to the head of the second drying drum 10 by a connecting assembly 15 and the connecting assembly 15 cannot rotate, the combustion chamber includes a first combustion chamber 7 and a second combustion chamber 12, the first combustion chamber 7 feeds high-temperature flue gas into the first drying drum 4 through the connecting assembly 15, and the second combustion chamber 12 is close to the tail of the second drying drum 10 and feeds high-temperature flue gas into the second drying drum 10.

[0023] like Figure 1 - Figure 3 As shown, the utility model also discloses the following more optimized specific structures:

[0024] In order to facilitate the uniform delivery of the high-temperature flue gas from the first combustion chamber 7 into the drying drum, the connecting assembly 15 includes an annular outer connecting cylinder 20 and an annular inner connecting cylinder 23. The outer connecting cylinder 20 is mounted on the outside of the inner connecting cylinder 23, and the outer connecting cylinder 20 is installed on the ground or other equipment through a mounting bracket (not shown in the figure). The circumferential inner wall of the outer connecting cylinder 20 is provided with a concave ring 21 formed by an inward concave, and the circumferential outer wall of the outer connecting cylinder 20 is provided with an interface (not marked in the figure) communicating with the concave ring 21, and the interface is connected to the high-temperature flue gas pipe 6 of the first combustion chamber 7. A plurality of radially penetrating air intake holes (refer to the upward air intake holes 22 and the downward air intake holes 26 described below) are provided in the cylinder wall of the inner connecting cylinder 23 along the circumferential direction. The outer ends of all the air intake holes are located in the concave ring 21, and the inner ends of the air intake holes are communicated with the first drying drum 4 and the second drying drum 10. The tail of the first drying drum 4 and the head of the second drying drum 10 are respectively located outside the axial ends of the inner connecting cylinder 23 and are respectively butted against each other.

[0025] In order to make most of the high-temperature flue gas in the first combustion chamber 7 enter the first drying drum 4 more quickly to dehydrate the feed with high humidity at high temperature, and at the same time to use part of the high-temperature flue gas in the first combustion chamber 7 to push the raw materials passing through the inner connecting tube 23 downward to avoid the accumulation of raw materials, the multiple air intake holes in the middle and upper wall of the inner connecting tube 23 are all upward air intake holes 22, and a section of the upward air intake hole 22 close to the inner end is bent toward the direction close to the first drying drum 4 (the bending angle is determined according to actual needs, for example, after bending, the angle between its center line and the axial direction of the inner connecting tube 23 is 80°), so that The high-temperature flue gas flows upward faster, that is, flows toward the head of the first drying drum 4, so that the temperature inside the first drying drum 4 is higher and the temperature rises faster. The multiple air inlet holes in the lower wall of the inner connecting cylinder 23 are all downward air inlet holes 26. A section of the downward air inlet hole 26 close to the inner end is bent toward the direction close to the second drying drum 10 (the bending angle is determined according to actual needs, for example, after bending, the angle between its center line and the axial direction of the inner connecting cylinder 23 is 80°). In this way, the high-temperature flue gas can flow downward faster, that is, flow toward the tail of the second drying drum 10, so as to push the raw materials to quickly enter the second drying drum 10.

[0026] In order to facilitate processing and assembly, and at the same time to ensure a better sealing effect between the inner connecting cylinder 23 and the two drying drums, the axial ends of the inner connecting cylinder 23 are respectively extended to the outside of the two ends near the outer peripheral edge to form limit rings 24, and the inner walls of the two limit rings 24 are respectively in contact with the outer wall of the tail of the first drying drum 4 and the outer wall of the head of the second drying drum 10. The circumferential inner wall surface of the inner connecting cylinder 23, the circumferential inner wall surface of the first drying drum 4 and the circumferential inner wall surface of the second drying drum 10 are flush with each other, and annular annular bosses 17 are respectively provided on the circumferential outer wall of the first drying drum 4 near the tail and on the circumferential outer wall of the second drying drum 10 near the head. The outer ends of the two limit rings 24 are respectively close to the corresponding ends of the two annular bosses 17 and a first sealing ring 25 is installed in the gap. The axial ends of the circumferential inner walls of the outer connecting cylinder 20 are respectively provided with "L"-shaped annular grooves (not marked in the figure), and the corresponding ends of the two annular bosses 17 are respectively placed in the two annular grooves.

[0027] In order to achieve a better sealing effect, a second sealing ring 19 is installed between the corresponding end of the annular boss 17 and the groove wall of the corresponding annular groove of the external connecting tube 20 .

[0028] In order to further achieve a better sealing effect, the outer walls at both axial ends of the external connection tube 20 are respectively connected to one end of two sets of elastic sealing sheets 18 , and the other ends of the two sets of elastic sealing sheets 18 are respectively in contact with the outer walls of the two annular bosses 17 .

[0029] In order to perform more precise temperature control on the first drying drum 4 and the second drying drum 10, a first temperature sensor 3 is provided on the drum wall of the first drying drum 4 (whether it is installed on the inner wall or the outer wall, and in the middle section, the head or the tail according to actual needs), and a second temperature sensor 8 is provided on the drum wall of the second drying drum 10 (whether it is installed on the inner wall or the outer wall, and in the middle section, the head or the tail according to actual needs). The signal output end of the first temperature sensor 3 and the signal output end of the second temperature sensor 8 are respectively connected to the signal input end of the controller (not shown in the figure) or respectively connected to the signal input end of the temperature display (not shown in the figure).

[0030] Figure 1 The figure also shows a drum head cover 1 installed on the head of the first drying drum 4, a material receiver 2 is provided at the lower part of the drum head cover 1, a drum tail cover 11 is installed on the tail of the second drying drum 10, a first driven gear 5 is installed on the outer wall of the first drying drum 4, a rotating shaft of the first drive motor 14 is connected to the first driving gear (not marked in the figure), the first driving gear is meshed and connected with the first driven gear 5, so as to realize the rotational drive of the first drying drum 4, and the positions near the head and the tail of the first drying drum 4 are respectively placed on two first tugs 13, and the first tugs 13 are installed on the ground or other equipment through a mounting bracket (not shown in the figure) to realize the rotation of the first drying drum 4. The second driven gear 9 is mounted on the outer wall of the second drying drum 10, and the rotating shaft of the second driving motor 17 is connected to the second driving gear (not marked in the figure), and the second driving gear is meshed and connected with the second driven gear 9 to realize the rotational drive of the second drying drum 10. The positions near the head and the tail of the second drying drum 10 are respectively placed on two second tugwheels 16, and the second tugwheels 16 are installed on the ground or other equipment through a mounting bracket (not shown in the figure) to support the second drying drum 10 and realize the free rotation function of the second drying drum 10; these structures are all conventional adaptive structures.

[0031] like Figure 1 - Figure 3 As shown, when used, the ferrous sulfate monohydrate preparation component based on two-stage high-temperature dehydration of the utility model is combined with other equipment of the ferrous sulfate monohydrate preparation system. The types and quantities of other equipment are determined according to actual needs and are not described here. The following is a specific description of the process in which the raw material ferrous sulfate heptahydrate is dried and dehydrated in this component to become ferrous sulfate monohydrate.

[0032] The raw material ferrous sulfate heptahydrate first enters the head of the first drying drum 4, and the high-temperature flue gas in the first drying drum 4 dehydrates the raw material at high temperature. The free water in the ferrous sulfate heptahydrate is evaporated at high temperature, and part of the crystal water in the ferrous sulfate heptahydrate will also become free water and evaporate, and gradually reach the tail of the first drying drum 4 during the continuous rotation of the first drying drum 4. In this process, the ferrous sulfate heptahydrate is dehydrated to become ferrous sulfate tetrahydrate or ferrous sulfate trihydrate, and then enters the head of the second drying drum 10 through the inner connecting cylinder 23. In this process, the raw material located in the middle and lower part of the inner connecting cylinder 23 is blown by part of the high-temperature flue gas of the first combustion chamber 7, so that it can go down smoothly and avoid accumulation; the ferrous sulfate tetrahydrate or ferrous sulfate trihydrate is continuously heated and dehydrated by the high-temperature flue gas of the second combustion chamber 12 in the second drying drum 10, and is just dehydrated to become ferrous sulfate monohydrate when it reaches the tail of the second drying drum 10, and then sent to other equipment through the drum tail cover 11.

[0033] During operation, the first temperature sensor 3 and the second temperature sensor 8 respectively detect the temperatures in the first drying drum 4 and the second drying drum 10 in real time, which is used as a basis for controlling the duration of high-temperature flue gas from the first combustion chamber 7 and the second combustion chamber 12 being fed into the first drying drum 4 and the second drying drum 10. The temperatures in the first drying drum 4 and the second drying drum 10 are adjusted in real time, thereby achieving a more precise temperature control function, so that the purity of the finished ferrous sulfate monohydrate is higher and the production efficiency is higher.

[0034] The above embodiments are only preferred embodiments of the present utility model and are not limitations on the technical solutions of the present utility model. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present utility model.

Claims

1. A ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration, comprising a drying drum and a combustion chamber for providing high-temperature flue gas to the drying drum, wherein the head of the drying drum is higher than the tail and can rotate, characterized in that: The drying drum is formed by connecting a first drying drum and a second drying drum, the head of the first drying drum serves as the head of the drying drum, the tail of the second drying drum serves as the tail of the drying drum, the tail of the first drying drum is connected to the head of the second drying drum by a connecting assembly and the connecting assembly cannot rotate, the combustion chamber includes a first combustion chamber and a second combustion chamber, the first combustion chamber supplies high-temperature flue gas into the first drying drum through the connecting assembly, and the second combustion chamber is close to the tail of the second drying drum and supplies high-temperature flue gas into the second drying drum.

2. The ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration according to claim 1, characterized in that: The connecting assembly includes an annular outer connecting cylinder and an annular inner connecting cylinder, the outer connecting cylinder is sleeved on the outside of the inner connecting cylinder, the circumferential inner wall of the outer connecting cylinder is provided with a concave ring formed by an inward concave, the circumferential outer wall of the outer connecting cylinder is provided with an interface communicated with the concave ring and the interface is connected to the high-temperature flue gas pipe of the first combustion chamber, a plurality of radially penetrating air intake holes are provided in the cylinder wall of the inner connecting cylinder along the circumferential direction, the outer ends of all the air intake holes are located in the concave ring, the inner ends of the air intake holes are communicated with the first drying drum and the second drying drum, the tail of the first drying drum and the head of the second drying drum are respectively located outside the axial ends of the inner connecting cylinder and are respectively butted against each other.

3. The ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration according to claim 2, characterized in that: The multiple air inlet holes in the middle and upper wall of the inner connecting cylinder are all ascending air inlet holes, and a section of the ascending air inlet holes close to the inner end is bent toward the first drying drum. The multiple air inlet holes in the lower wall of the inner connecting cylinder are all descending air inlet holes, and a section of the descending air inlet holes close to the inner end is bent toward the second drying drum.

4. The ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration according to claim 2, characterized in that: The axial ends of the inner connecting cylinder extend outwards from both ends near the outer edge positions to form limit rings, and the inner walls of the two limit rings are respectively in contact with the outer wall of the tail of the first drying drum and the outer wall of the head of the second drying drum, the circumferential inner wall surface of the inner connecting cylinder, the circumferential inner wall surface of the first drying drum and the circumferential inner wall surface of the second drying drum are flush with each other, and annular ring bosses are respectively provided on the circumferential outer wall of the first drying drum near the tail and on the circumferential outer wall of the second drying drum near the head, the outer ends of the two limit rings are respectively close to the corresponding ends of the two annular bosses and a first sealing ring is installed in the gap, and the circumferential inner walls of the axial ends of the outer connecting cylinder are respectively provided with "L"-shaped annular grooves, and the corresponding ends of the two annular bosses are respectively placed in the two annular grooves.

5. The ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration according to claim 4, characterized in that: A second sealing ring is installed between the corresponding end of the annular boss and the groove wall of the corresponding annular groove of the external connecting tube.

6. The ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration according to claim 5, characterized in that: The outer walls at both axial ends of the external connection tube are respectively connected to one end of two groups of elastic sealing sheets, and the other ends of the two groups of elastic sealing sheets are respectively in contact with the outer walls of the two annular bosses.

7. The ferrous sulfate monohydrate preparation assembly based on two-stage high-temperature dehydration according to any one of claims 1 to 6, characterized in that: A first temperature sensor is provided on the wall of the first drying drum, and a second temperature sensor is provided on the wall of the second drying drum. The signal output end of the first temperature sensor and the signal output end of the second temperature sensor are respectively connected to the signal input end of the controller or respectively connected to the signal input end of the temperature display.

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