System for producing iron ore concentrate and co-producing phosphate concentrate by using ferrous sulfate

Abstract

The utility model discloses a system for producing iron ore concentrate and co-producing phosphate concentrate by ferrous sulfate, which comprises a rotary kiln, the rotary kiln is connected with a desulfurizing tower through a pipeline, the desulfurizing tower is connected with a slurry delivery pump through a pipeline, the slurry delivery pump is connected with a gypsum filter through a pipeline, and the gypsum filter is connected with an acid decomposer through a pipeline. The rotary kiln is connected with the reaction tank through a pipeline, the reaction tank is connected with the phosphorite filter through a pipeline, the phosphorite filter is connected with the acid decomposer through a pipeline, and the acid decomposer is connected with the desulfurization tower through a pipeline. Meanwhile, production and processing of iron ore concentrate, phosphoric acid, gypsum and phosphate concentrate are achieved, meanwhile, flue gas desulfurization of calcium-containing acidolysis solution resources flowing back to ferrous sulfate processing is achieved, continuous circulating production and processing can be achieved, and good economic benefits and environmental protection benefits are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of iron concentrate and phosphate concentrate production, in particular to a system for producing iron concentrate and phosphate concentrate from ferrous sulfate. Background Art

[0002] Ferrous sulfate, a byproduct of titanium dioxide, is currently mainly used in the production of cement chromium reduction agent, feed additive (monohydrate), polyferrous sulfate, sulfuric acid blending and other traditional applications. The traditional downstream is saturated; a large number of uses are used in the production of iron phosphate. Recently, due to the overcapacity of iron phosphate, the demand has been greatly reduced. There is an urgent need to develop new uses, increase consumption, and improve added value.

[0003] Ferrous sulfate is rich in iron and sulfur and is a good resource of iron and sulfur. Currently, only a small amount of ferrous sulfate is calcined to produce iron red, and the sulfur resource is simply neutralized with lime. When ferrous sulfate is processed and calcined at high temperature, the iron trioxide (containing 70% iron) produced is a high-quality iron concentrate, but it also produces a large amount of sulfur trioxide and sulfur dioxide flue gas, which brings major environmental problems.

[0004] There is currently no technology for producing iron concentrate and phosphate concentrate by desulfurizing ferrous sulfate. The production system formed by combining various processes is a major breakthrough. Summary of the invention

[0005] The utility model aims to provide a system for producing iron concentrate and phosphate concentrate by using ferrous sulfate to solve the problems raised in the above-mentioned background technology.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A system for producing iron concentrate and phosphate concentrate from ferrous sulfate, comprising a rotary kiln, the rotary kiln is connected to a desulfurization tower through a pipeline, the desulfurization tower is connected to a slurry delivery pump through a pipeline, the slurry delivery pump is connected to a gypsum filter through a pipeline, the gypsum filter is connected to an acid decomposer through a pipeline, the gypsum filter is connected to a reaction tank through a pipeline, the reaction tank is connected to a phosphate ore filter through a pipeline, the phosphate ore filter is connected to the acid decomposer through a pipeline, the acid decomposer is connected to the desulfurization tower through a pipeline, the rotary kiln is connected to a ferrous sulfate bin through a pipeline, the rotary kiln is connected to a burner through a pipeline, and is connected to a cooler through a pipeline;

[0008] The rotary kiln is used for oxidative decomposition of ferrous sulfate to produce iron concentrate and sulfur trioxide and sulfur dioxide flue gas;

[0009] The desulfurization tower reacts with the flue gas and the calcium-containing acid solution to produce calcium sulfate (gypsum), thereby removing sulfur trioxide and sulfur dioxide from the flue gas, and the sulfur trioxide and sulfur dioxide flue gas enters the desulfurization tower;

[0010] The desulfurization tower reacts with the flue gas and the calcium-containing acid solution to produce calcium sulfate (gypsum), thereby removing sulfur trioxide and sulfur dioxide from the flue gas. The calcium sulfate is transported to the gypsum filter through a slurry delivery pump;

[0011] The slurry delivery pump is used to deliver gypsum slurry;

[0012] The gypsum filter is used to filter the gypsum slurry to obtain gypsum filter cake and phosphoric acid filtrate; the generated phosphoric acid filtrate enters the acid decomposer to react with the phosphate rock;

[0013] The acid decomposer is used for the reaction of phosphoric acid with phosphate rock to obtain calcium-containing acid solution which then flows back to the desulfurization tower.

[0014] The acid decomposer is provided with a crushing structure to assist the reaction and decompose part of the calcium-containing acid solution to flow back to the desulfurization tower.

[0015] The reaction tank is used for the reaction of phosphoric acid with phosphate ore to obtain phosphate concentrate slurry which flows into the phosphate ore filter;

[0016] The phosphate rock filter is used to filter the concentrate slurry to obtain phosphate concentrate and phosphoric acid filtrate. The phosphoric acid filtrate produced enters the acid decomposer, and then reacts with the phosphate rock to obtain calcium-containing acid solution, which is then refluxed to the desulfurization tower.

[0017] As a further solution of the utility model: the acid decomposer includes a decomposer shell, a feed pipe is arranged on the upper end surface of the decomposer shell, two groups of drive motors are arranged on the outer side wall of the decomposer shell, the output ends of the two groups of drive motors pass through the decomposer shell, extend to the inside of the decomposer shell, and are connected to a group of rotating rods, the other ends of the two groups of rotating rods are connected to the inner wall of the other end of the decomposer shell, and a group of crushing rollers are sleeved on the outer walls of the two groups of rotating rods.

[0018] As a further solution of the utility model: a group of first pulleys are sleeved on the outer side walls of the two groups of rotating rods, a group of connecting belts are sleeved on the outer sides of the two groups of first pulleys, a group of second pulleys are arranged inside the other side of the two groups of connecting belts, and the two groups of first pulleys and the second pulleys are rotatably connected to the inner wall of the decomposer housing.

[0019] As a further solution of the utility model: a group of first gears are arranged on the side walls of the two groups of the second pulleys, a group of second gears are meshed and connected to one side of the two groups of the first gears, a group of rotating rods are arranged inside the two groups of the second gears, and the two ends of the two groups of the rotating rods are respectively arranged on the inner walls on both sides of the decomposer housing.

[0020] As a further solution of the utility model: two groups of connecting parts are sleeved on the outer side walls of the two groups of rotating rods, and multiple groups of connecting rods are connected to the outer side walls of the two groups of connecting parts. A group of cleaning rollers are arranged at the other end of the multiple groups of connecting rods, and the cleaning rollers are in contact with the crushing rollers.

[0021] As a further solution of the utility model: a discharging piece is arranged on the lower end wall of the decomposer housing.

[0022] As a further solution of the utility model: a group of vertical rods are arranged at the four corners of the lower end surface of the decomposer housing, two groups of horizontal plates are arranged on the lower end surfaces of the multiple groups of vertical rods, and a group of moving parts are arranged at both ends of the lower end surfaces of the two groups of horizontal plates.

[0023] As a further solution of the utility model: raw material ferrous sulfate is arranged inside the ferrous sulfate bin.

[0024] Compared with the prior art, the beneficial effects of the utility model are:

[0025] The system as a whole can realize the following production process: the raw material ferrous sulfate (anhydrous) in the ferrous sulfate bin enters the rotary kiln, the pulverized coal is burned by the burner to provide heat for the inside of the rotary kiln, the cold air exchanges heat with the iron concentrate discharged from the rotary kiln in the cooler to recover heat and enter the burner for combustion assistance, and the ferrous sulfate is oxidized and decomposed by heat in the rotary kiln to produce ferric oxide (iron concentrate) and sulfur trioxide and sulfur dioxide flue gas; the sulfur trioxide and sulfur dioxide flue gas enter the desulfurization tower to react with the calcium-containing acid solution to produce calcium sulfate, and the calcium sulfate is transported through the slurry The product is transported to the gypsum filter by a pump to form a filter cake of calcium sulfate product and phosphoric acid filtrate. Part of the phosphoric acid filtrate flows into the acid decomposer for reuse, and part of the phosphoric acid enters the reaction tank. In the reaction tank, phosphoric acid reacts with phosphate ore to obtain phosphate concentrate slurry. The phosphate concentrate slurry is filtered through a phosphate ore filter to form phosphate concentrate and phosphoric acid filtrate. The phosphoric acid filtrate then flows into the acid decomposer for reuse. The acid decomposer decomposes to form calcium-containing acid solution, which then flows into the desulfurization tower for continuous and cyclic use, forming a comprehensive system for producing phosphoric acid, iron concentrate, phosphate concentrate, gypsum and flue gas desulfurization with ferrous sulfate.

[0026] In the system, by arranging a decomposer housing, a feed pipe, a drive motor, a rotating rod, a crushing roller, a first pulley, a connecting belt, a second pulley, a first gear, a second gear, a rotating rod, a connecting piece, a connecting rod and a cleaning roller, the raw phosphate ore and phosphoric acid entering the acid decomposer can be crushed, so that the raw phosphate ore and phosphoric acid can be decomposed better and more quickly. At the same time, the residue on the crushing roller can be scraped off by multiple groups of cleaning rollers to avoid raw materials remaining on the crushing roller, thereby improving the production efficiency of iron ore concentrate and phosphate concentrate, and it is relatively practical.

[0027] In this system, the multiple connections formed by the rotary kiln realize the production of iron concentrate by combining ferrous sulfate and pulverized coal as raw materials. At the same time, the sulfur element in sulfur trioxide and sulfur dioxide flue gas reacts with the calcium-containing acid solution in the desulfurization tower to generate slurry, thereby achieving the smooth operation and production of the overall system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the connection diagram of the production system of the utility model.

[0029] Figure 2 It is a schematic diagram of the structure of the decomposer of the utility model.

[0030] Figure 3 It is a schematic diagram of the internal structure of the decomposer of the utility model.

[0031] Figure 4 For the utility model Figure 3 A is a schematic diagram of the enlarged structure.

[0032] Figure 5 The schematic diagram of the rotary kiln structure of the utility model is as follows

[0033] Figure 6 The utility model is a schematic diagram of the kiln tail structure of the rotary kiln

[0034] Figure 7 Schematic diagram of the cross-sectional structure of the kiln shell of the rotary kiln of the utility model

[0035] Numbers in the figure: Among them: 1, rotary kiln; 2, desulfurization tower; 3, slurry delivery pump; 4, gypsum filter; 5, acid decomposer; 6, reaction tank; 7, phosphate rock filter; 8, ferrous sulfate bin; 9, burner; 10, cooler; 101, kiln body; 1011, refractory mud; 1012, refractory brick; 102, kiln tail; 103, kiln head; 1109, driving mechanism; 1110, bracket; 1111, roller; 1112, load-bearing ring; 13, raw material inlet; 14, smoke exhaust pipe; 1401, circulation slot; 15, discharge port;

[0036] 511. decomposer housing; 512. feed pipe; 513. drive motor; 514. rotating rod; 515. crushing roller; 516. first pulley; 517. connecting belt; 518. second pulley; 519. first gear; 520. second gear; 521. rotating rod; 522. connecting piece; 523. connecting rod; 524. cleaning roller; 525. discharging piece; 526. vertical rod; 527. horizontal plate; 528. moving piece. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with flow charts and embodiments.

[0038] As shown in the figure, a system for producing iron concentrate and phosphate concentrate by using ferrous sulfate, the reflux system includes a rotary kiln 1, a desulfurization tower 2, a slurry delivery pump 3, a gypsum filter 4, and an acid decomposer 5. The exhaust end of the rotary kiln 1 is connected to the desulfurization tower 2 through a pipeline, the slurry discharge end of the desulfurization tower 2 is connected to the slurry delivery pump 3 through a pipeline, the output end of the slurry delivery pump 3 is connected to the gypsum filter 4 through a pipeline, the gypsum filter 4 is connected to the acid decomposer 5 through a pipeline, and the acid decomposer 5 is refluxed and connected to the desulfurization tower 2. At the same time, the gypsum filter 4 is connected to a reaction tank 6 through a pipeline, the reaction tank 6 is connected to a phosphate filter 7 through a pipeline, and the phosphate filter 7 is also connected to the acid decomposer 5 through a pipeline. The rotary kiln 1 is connected to a ferrous sulfate bin 8 through a pipeline, the rotary kiln 1 is connected to a burner 9 through a pipeline, and is connected to a cooler 10 through a pipeline.

[0039] The rotary kiln 1 is used for oxidative decomposition of ferrous sulfate to produce iron concentrate and sulfur trioxide and sulfur dioxide flue gas, and the sulfur trioxide and sulfur dioxide flue gas enter the desulfurization tower 2;

[0040] The desulfurization tower 2 reacts with the flue gas and the calcium-containing acid solution to produce calcium sulfate, thereby removing sulfur trioxide and sulfur dioxide from the flue gas. The calcium sulfate is transported to the gypsum filter 4 through the slurry delivery pump 3;

[0041] The slurry delivery pump 3 is used to deliver gypsum slurry;

[0042] The gypsum filter 4 is used to filter the gypsum slurry to obtain gypsum filter cake and phosphoric acid filtrate, and the phosphoric acid filtrate enters the acid decomposer 5 to react with phosphate rock;

[0043] The acid decomposer 5 is used for the reaction of phosphoric acid with phosphate rock to obtain a calcium-containing acid solution;

[0044] The reactor 6 is used for the reaction of phosphoric acid with phosphate ore to obtain phosphate concentrate slurry;

[0045] The phosphate rock filter 7 is used to filter the concentrate slurry to obtain phosphate concentrate and filtrate.

[0046] The acid decomposer 5 is provided with a crushing structure to assist the reaction and decompose the calcium-containing acid solution to flow back to the desulfurization tower 2 .

[0047] The phosphate rock filter 7 decomposes the phosphate concentrate and the filtrate, and the filtrate is then returned to the acid decomposer 5 for phosphoric acid to react with the phosphate rock to obtain a calcium-containing acid solution.

[0048] The above system can be used to achieve the following: the raw material ferrous sulfate (anhydrous) in the ferrous sulfate bin enters the rotary kiln, the pulverized coal is burned by the burner to provide heat for the inside of the rotary kiln, the cold air exchanges heat with the iron concentrate discharged from the rotary kiln in the cooler to recover heat and enter the burner to assist combustion, and the ferrous sulfate is oxidized and decomposed by heat in the rotary kiln to produce ferric oxide (iron concentrate) and sulfur trioxide and sulfur dioxide flue gas; the sulfur trioxide and sulfur dioxide flue gas enter the desulfurization tower 2 to react with the calcium-containing acid solution to produce calcium sulfate, and the above system can be used to achieve the following: The calcium sulfate is transported to the gypsum filter 4 through the slurry delivery pump 3 to form a filter cake of calcium sulfate product and phosphoric acid filtrate. Part of the phosphoric acid filtrate flows into the acid decomposer for reuse, and part of the phosphoric acid enters the reaction tank; in the reaction tank, phosphoric acid reacts with phosphate ore to obtain phosphate concentrate slurry, and the phosphate concentrate slurry is filtered into phosphate concentrate and phosphoric acid filtrate through the phosphate ore filter 7. The phosphoric acid filtrate flows into the acid decomposer for reuse, and the acid decomposer decomposes to form calcium-containing acid solution, which then flows into the desulfurization tower 2 for continuous and cyclic use, forming a circular production system.

[0049] The above process system is a comprehensive system for producing phosphoric acid, iron ore, phosphate concentrate, gypsum and flue gas desulfurization based on ferrous sulfate, and is also a single product processing system or flue gas desulfurization system of phosphoric acid, iron ore, phosphate concentrate or gypsum.

[0050] Based on the above system, a method for producing iron concentrate and phosphate concentrate is formed, that is, the collective rotary kiln 1, the desulfurization tower 2, the gypsum filter 4, the phosphate ore filter 7, and the acid decomposer 5 are connected as the main components, and the ferrous sulfate-based iron concentrate production and phosphate concentrate reflux system is used. Through the desulfurization of the desulfurization tower based on the ferrous sulfate rotary kiln 1, the production of iron concentrate and the phosphate concentrate circulation, the reaction steps and reflux circulation processing of multiple processes are integrated, including the following:

[0051] A. The raw material ferrous sulfate (anhydrous) enters the rotary kiln (1), the pulverized coal is burned by the burner to provide heat for the rotary kiln, the cold air exchanges heat with the iron concentrate discharged from the rotary kiln in the cooler to recover heat and enter the burner to assist combustion, and the ferrous sulfate is oxidized and decomposed by heat in the rotary kiln to produce ferric oxide (iron concentrate) and sulfur trioxide and sulfur dioxide flue gas;

[0052] B. The raw phosphate ore and phosphoric acid enter the acid decomposer 5, where the phosphate ore and phosphoric acid undergo a decomposition reaction to obtain a calcium-containing acid solution;

[0053] C. The calcium-containing acid solution enters the desulfurization tower 2, where calcium ions react chemically with sulfur trioxide and sulfur dioxide in the flue gas to generate calcium sulfate and calcium sulfite precipitation, wherein the calcium sulfite is further oxidized to obtain calcium sulfate, and the calcium sulfate slurry is transported to the gypsum filter 4 through the slurry pump 3;

[0054] D. The filter cake produced by the gypsum filter is a calcium sulfate product, and the filtrate is phosphoric acid, a part of which is recycled to the acid decomposer, and a part of which enters the reaction tank 6;

[0055] E. Phosphoric acid reacts with phosphate ore in the reaction tank to obtain phosphate concentrate slurry, which is filtered by a phosphate filter 7, and the filter cake is a phosphate concentrate product. The filtrate is recycled to the acid decomposer, and the acid decomposer decomposes the calcium-containing acid solution and refluxes it to the desulfurization tower 2 for continuous desulfurization;

[0056] The above steps are cycled in sequence to form a cyclic processing production of iron concentrate and phosphate concentrate based on ferrous sulfate.

[0057] The overall process reaction formula is: FeSO4·7H20→FeSO4·H20+6H2O, FeSO4·7H20→FeSO4+7H20, 2FeSO4·H20→Fe2O3+SO2+SO3+H20, 2FeSO4→Fe2O3+SO2+SO3, Ca5F(PO4)3+7H3PO4→5Ca(H2PO4)2+HF, Ca(H2PO4)2+SO2+H20→CaSO3+2H3PO4, 2CaSO3+O2→2CaSO4.

[0058] The raw material of step A is anhydrous ferrous sulfate, and the rotary kiln operating conditions are: temperature 900-950° C., and reaction time 1 hour.

[0059] The concentration of phosphoric acid in step B is 35-40%, the P2O5 content of phosphate ore is 15-20%, and the acid decomposer is controlled under the following process conditions: the reaction temperature of the desulfurization tower is 60°C-80°C, the reaction time is 1 hour, and the liquid-solid ratio is 2.5-3:1.

[0060] The flue gas temperature of the desulfurization tower (2) is 130° C. to 150° C., the concentration of the calcium acid solution (in terms of Ca) is 3% to 5%, and the liquid-to-gas ratio is 1:1000.

[0061] In the step E, the concentration of phosphoric acid is 35-40%, the content of P2O5 in the phosphate ore is 15-20%, and the process conditions controlled by the reactor are: temperature 60° C.-80° C., and reaction time 2 hours.

[0062] Right now:

[0063] High temperature calcination mechanism: The ferrous sulfate heptahydrate is treated by a two-step process of drying and calcination. The drying temperature is controlled at 400-450°C to dehydrate the ferrous sulfate heptahydrate to obtain monohydrate and anhydrous ferrous sulfate. The monohydrate and anhydrous ferrous sulfate enter the rotary kiln for high temperature calcination at a controlled temperature of 900-950°C for 60 minutes. The reactions involved are: FeSO4·7H20→FeSO4·H20+6H2O, FeSO4·7H20→FeSO4+7H20, 2FeSO4·H20→Fe2O3+SO2+SO3+H20, 2FeSO4→Fe2O3+SO2+SO3

[0064] Acid hydrolysis mechanism: phosphoric acid is used to react with phosphate rock to generate calcium-containing acid hydrolysis solution, which contains water-soluble calcium dihydrogen phosphate. The main reaction involved is: Ca5F(PO4)3+7H3PO4→5Ca(H2PO4)2+HF

[0065] Desulfurization mechanism: Calcium dihydrogen phosphate in the calcium-containing acid solution reacts chemically with sulfur dioxide in the flue gas to form calcium sulfite precipitate, which is further oxidized to obtain calcium sulfate (gypsum) precipitate. The main reactions are: Ca(H2PO4)2+SO2+H20→CaSO3+2H3PO4, 2CaSO3+O2→2CaSO4, and the gypsum filter uses general slurry placed in a storage tank with an agitator for crystal growth, with a residence time of 6 to 8 hours.

[0066] The rotary kiln 1 may specifically refer to the following structure, but it is not the only structure:

[0067] The rotary kiln 1 comprises a kiln body 101, a kiln tail 102 and a kiln head 103. A driving mechanism 1109 is arranged on the outer side of the middle of the kiln body 101, and the driving mechanism 1109 is installed on a bracket 1110. Load-bearing rings 1112 are arranged at both ends of the kiln body 101. The bracket 1110 is located on one side of the load-bearing ring 1112 and is equipped with a roller 1111. As shown in the figure, a raw material inlet 13 is arranged on one side of the upper end of the kiln tail 102, and a smoke exhaust pipe 14 is arranged on the side of the kiln tail 102 close to the raw material inlet 13. The smoke exhaust pipe 14 is connected to the desulfurization tower 2, and a flow groove 1401 is arranged between the smoke exhaust pipe 14 and the raw material inlet 13. The flow groove 1401 facilitates the transportation of smoke to the smoke exhaust pipe 14. The kiln tail 102 is movably connected to one end of the kiln body 101, and the raw material inlet 13 is connected to the ferrous sulfate bin 8 through a pipeline.

[0068] Among them, the kiln head 103 is located near the bottom of one end of the kiln body 101 and is provided with a discharge port 15. The inside of the kiln head 103 is movably connected to the other end of the kiln body 101. The discharge port 15 is connected to a cooler 10. The inside of the kiln body 101 is provided with refractory mud 1011. The inside of the refractory mud 1011 is provided with refractory bricks 1012. The number of refractory bricks 1012 is set to several. The kiln head 103 is connected to the burner 9. The kiln head 103 is connected to the bracket 1110 through a guide rail. The rotary kiln in the system forms multiple connections to realize reaction conversion, realize ferrous sulfate and coal powder raw materials, and achieve the output of iron concentrate. At the same time, the sulfur element in sulfur trioxide and sulfur dioxide flue gas reacts with calcium-containing acid solution in the desulfurization tower to generate slurry to further achieve good operation and processing of the overall system.

[0069] The acid decomposer can refer to the following structure, but it is not the only structure: as shown in the figure, the acid decomposer 5 includes a decomposer shell 511, a feed pipe 512 is arranged on the upper end surface of the decomposer shell 511, and two groups of drive motors 513 are arranged on the outer wall of the decomposer shell 511. The output ends of the two groups of drive motors 513 pass through the decomposer shell 511 and extend to the inside of the decomposer shell 511, and are connected to a group of rotating rods 514. The other ends of the two groups of rotating rods 514 are connected to the inner wall of the other end of the decomposer shell 511, and the outer walls of the two groups of rotating rods 514 are sleeved with a group of crushing rollers 515; the outer walls of the two groups of rotating rods 514 are sleeved with a group of first belts 516, and the outer sides of the two groups of first pulleys 516 are sleeved with a group of connecting belts 517. The two groups of connecting belts 517 A group of second pulleys 518 are arranged inside the other side, and the two groups of first pulleys 516 and the second pulleys 518 are rotatably connected to the inner wall of the decomposer housing 511; a group of first gears 519 are arranged on the side walls of the two groups of second pulleys 518, and one side of the two groups of first gears 519 is meshed and connected with a group of second gears 520, and a group of rotating rods 521 are arranged inside the two groups of second gears 520, and the two ends of the two groups of rotating rods 521 are respectively arranged on the inner walls of the two sides of the decomposer housing 511; two groups of connecting members 522 are sleeved on the outer walls of the two groups of rotating rods 521, and multiple groups of connecting rods 523 are connected to the outer walls of the two groups of connecting members 522, and the other ends of the multiple groups of connecting rods 523 are provided with a group of cleaning rollers 524, and the cleaning rollers 524 are in contact with the crushing rollers 515;

[0070] A discharge piece 525 is provided on the lower end wall of the decomposer housing 511; the material produced by the decomposition reaction can be discharged by providing the discharge piece 525. A set of vertical rods 526 are provided at the four corners of the lower end surface of the decomposer housing 511, and two sets of horizontal plates 527 are provided on the lower end surfaces of the multiple sets of vertical rods 526. A set of moving pieces 528 are provided at both ends of the lower end surfaces of the two sets of horizontal plates 527; the vertical rods 526 can support the horizontal plates 527, and the horizontal plates 527 can support the moving pieces 528, and the moving pieces 528 can facilitate the transfer of the device.

[0071] When the acid decomposer 5 is in use, the raw phosphate ore and phosphoric acid are transported to the interior of the decomposer housing 511 through the feed pipe 512, and two sets of drive motors 513 are started at the same time. The two sets of drive motors 513 drive two sets of crushing rollers 515 to crush the raw phosphate ore and phosphoric acid through two sets of rotating rods 514, so that the raw phosphate ore and the phosphoric acid provided for the first time can be decomposed better and faster. While rotating, the rotating rod 514 drives the first gear 519 to rotate through the first pulley 516, the connecting belt 517 and the second pulley 518. The first gear 519 drives the rotating rod 21 to rotate through the second gear 520. The rotating rod 521 drives multiple sets of cleaning rollers 524 to rotate through the connecting piece 522, so that the multiple sets of cleaning rollers 524 can scrape the residue on the crushing rollers 515 to avoid the raw materials remaining on the crushing rollers 515. It is relatively practical and ensures the full decomposition reaction of the material. The crushing structure is set to assist the reaction to decompose the calcium-containing acid solution, so that the phosphate ore and phosphoric acid undergo a decomposition reaction to obtain the calcium-containing acid solution and return it to the desulfurization tower, so that the calcium ions react chemically with sulfur trioxide and sulfur dioxide in the flue gas to generate calcium sulfate and calcium sulfite precipitation, thereby realizing the continuity of the process and the connected operation of the overall system.

[0072] Its desulfurization tower, slurry delivery pump, gypsum filter, cooler, ferrous sulfate bin, burner, reaction tank, and phosphate rock filter are conventional equipment and can be directly used in the system using existing equipment.

[0073] By adopting the above system, multiple processes can be integrated into one processing, and the calcium-containing acid hydrolysis solution generated by the reaction of phosphoric acid and phosphate rock only once can be used as a desulfurizer, so that the entire system or process can continuously produce the calcium-containing acid hydrolysis solution from one process or system production to remove sulfur trioxide and sulfur dioxide in the flue gas of ferrous sulfate calcination. At the same time, the iron trioxide produced by ferrous sulfate calcination contains nearly 70% iron, which is high-quality iron concentrate. The calcium-containing acid hydrolysis solution resource produced in the circulation system is then desulfurized, and the production of phosphoric acid and phosphate concentrate does not require sulfuric acid raw materials, which reduces the production cost of phosphoric acid. At the same time, gypsum output is achieved, and multiple processes are integrated into one circular production, which solves the problem of phosphoric acid production not requiring sulfuric acid raw materials, greatly reduces the production cost of phosphoric acid, and has good economic and environmental benefits.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate, characterized in that: The invention comprises a rotary kiln (1), wherein the rotary kiln (1) is connected to a desulfurization tower (2) via a pipeline, the desulfurization tower (2) is connected to a slurry delivery pump (3) via a pipeline, the slurry delivery pump (3) is connected to a gypsum filter (4) via a pipeline, the gypsum filter (4) is connected to an acid decomposer (5) via a pipeline, the gypsum filter (4) is connected to a reaction tank (6) via a pipeline, the reaction tank (6) is connected to a phosphate rock filter (7) via a pipeline, the phosphate rock filter (7) is connected to the acid decomposer (5) via a pipeline, the acid decomposer (5) is connected to the desulfurization tower (2) via a pipeline, the rotary kiln (1) is connected to a ferrous sulfate bin (8) via a pipeline, the rotary kiln (1) is connected to a burner (9) via a pipeline, and is also connected to a cooler (10) via a pipeline.

2. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate as claimed in claim 1, characterized in that: The rotary kiln (1) is used for oxidative decomposition of ferrous sulfate to produce iron concentrate and sulfur trioxide and sulfur dioxide flue gas, and the sulfur trioxide and sulfur dioxide flue gas enter the desulfurization tower (2).

3. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate as claimed in claim 2, characterized in that: The desulfurization tower (2) reacts the flue gas with the calcium-containing acid solution to produce calcium sulfate gypsum, thereby removing sulfur trioxide and sulfur dioxide from the flue gas. The calcium sulfate is transported to the gypsum filter (4) through the slurry delivery pump (3).

4. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate as claimed in claim 2, characterized in that: The slurry delivery pump (3) is used for delivering gypsum slurry.

5. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate as claimed in claim 4, characterized in that: The gypsum filter (4) is used to filter the gypsum slurry to obtain gypsum filter cake and phosphoric acid filtrate. The generated phosphoric acid filtrate enters the acid decomposer (5) to react with phosphate rock.

6. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate as claimed in claim 2, characterized in that: The acid decomposer (5) is used for the reaction of phosphoric acid with phosphate rock to obtain a calcium-containing acid solution.

7. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate as claimed in claim 2, characterized in that: The reaction tank (6) is used for the reaction of phosphoric acid with phosphate ore to obtain phosphate concentrate slurry which flows into the phosphate ore filter (7).

8. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate as claimed in claim 2, characterized in that: The phosphate rock filter (7) is used to filter the concentrate slurry to obtain phosphate concentrate and filtrate. The filtrate is then refluxed to the acid decomposer (5) for phosphoric acid to react with the phosphate rock, and the calcium-containing acid solution is also refluxed to the desulfurization tower (2).

9. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate as claimed in claim 2, characterized in that: The rotary kiln is a multi-port connected rotary kiln.

10. A system for producing iron concentrate and phosphate concentrate by using ferrous sulfate as claimed in claim 6, characterized in that: A crushing structure is set up to assist the reaction and decompose the calcium-containing acid solution, so that the phosphate ore and phosphoric acid undergo a decomposition reaction to obtain the calcium-containing acid solution which is refluxed to the desulfurization tower.

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