Continuous premixing device

Abstract

The utility model belongs to the technical field of continuous acidolysis premixing, and particularly relates to a continuous premixing device which comprises a weighing bin, a first spiral conveyor, a venturi mixer and a second spiral conveyor, the first spiral conveyor is provided with a first feed port and a first discharge port, the weighing bin is connected with the first feed port, and the venturi mixer is connected with the second spiral conveyor. The venturi mixer is provided with a second feed port, a second discharge port and a liquid inlet, the second feed port is connected with the first discharge port, the liquid inlet is connected with a liquid inlet pipe, the second spiral conveyor is provided with a third feed port and a third discharge port, and the third feed port is connected with the second discharge port; compared with the prior art, continuous premixing production can be achieved, a traditional intermittent premixing technology is replaced, due to the fact that a chilled water system is omitted, energy consumption of products is reduced, real continuous automation of production is achieved through continuous premixing, and production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of continuous acid hydrolysis premixing, in particular to a continuous premixing device. Background Technique

[0002] Acid hydrolysis is one of the important links in the production of titanium white by the sulfuric acid method. The acid hydrolysis process is directly related to the quality of titanium liquid and the recovery rate of titanium. In the production of titanium dioxide by the sulfuric acid method, the reaction principles of batch acid hydrolysis and continuous acid hydrolysis are the same. Both are through the mixing of ilmenite and sulfuric acid, and the main reaction is triggered after the temperature is increased by the dilution heat of sulfuric acid. Ilmenite reacts with sulfuric acid to form soluble sulfates of titanium and iron. After adding water for leaching and dissolution, an aqueous solution of sulfates of titanium and iron (titanium sulfate, titanyl sulfate, ferrous sulfate and ferric sulfate) is formed. The waste gas discharged during the acid hydrolysis process contains water vapor, sulfur dioxide, hydrogen sulfide and dust, etc.

[0003] (1) Batch acid hydrolysis.

[0004] The metered sulfuric acid (mass fraction: 93% or 98%) and ore powder (qualified fineness) are successively put into the premixing tank for mixing. After stirring evenly, it is sent to the acid hydrolysis pot with air pressure stirring started, and then a certain amount of starting waste acid (waste acid mass fraction about 20% or process water) is added. After about 5 - 10 minutes, the main acid hydrolysis reaction occurs. After the main reaction, the solid phase formed is cured in the acid hydrolysis pot for 1.5 - 2 hours, then leached with process water, and the high-valent iron in the ore is reduced with iron powder. When a small amount of trivalent titanium appears in the material, it proves that the reduction operation is over, and at the same time, the whole acid hydrolysis reaction process is over, waiting for discharging.

[0005] (2) Continuous acid hydrolysis.

[0006] The flow rates of sulfuric acid (mass fraction 98%), ore powder (the fineness is 2% - 3% finer than that of batch acid hydrolysis) and starting waste acid (or process water) are set in DCS or PCL. First, part of the sulfuric acid is put into the premixing tank, then the ore is put and stirred evenly. When the specific gravity of the material reaches the process requirement, it flows by gravity to the main reactor, and the starting waste acid is added to the main reactor. In the main reactor, the material is heated to a certain temperature through sufficient stirring to carry out the main reaction. The material goes through the feeding pipe to the dissolution tank, and after being fully dissolved in the dissolution tank, it flows into the reduction tank. Then the set amount of iron powder is evenly added into the reduction tank. After sampling and analyzing that the trivalent titanium in the material in the tank meets the process requirements, it waits for discharging to the sedimentation tank.

[0007] The acidolysis premixing process is the main operation step in the early stage of the acidolysis reaction. The purpose is to mix the sulfuric acid and ilmenite powder involved in the reaction so that the ore powder is infiltrated with sulfuric acid and evenly dispersed in the sulfuric acid. The acidolysis premixing process directly affects the effect of acidolysis. The better the mixing effect of sulfuric acid and ilmenite powder, the more sufficient the acidolysis reaction and the less residual solid phase. If the concentrated sulfuric acid and ilmenite powder are not mixed sufficiently, the ilmenite powder will agglomerate in the sulfuric acid to form a dense and insoluble hard block, which affects the acidolysis rate. The traditional premixing method is intermittent premixing, that is, the measured concentrated sulfuric acid is first put into a steel acidolysis premixing tank with a stirring and cooling jacket, and the measured ilmenite powder is added under stirring conditions, stirred and mixed, and cooling water is passed into the cooling jacket for cooling (to prevent the temperature of the mixed slurry from rising and the acidolysis reaction occurs in advance). After stirring evenly, the material is discharged to the premixing transition tank and then to the acidolysis reactor. This premixing device includes a premixing tank, a premixing transition tank, a cold zone water tank and a chiller. The premix is ​​carried out intermittently in batches, and continuous feeding is achieved through the premixing transition layer. The continuous premixing device of the utility model eliminates the cold water tank, the cold water machine and the premixing transition tank, and adopts the weighing screw, the venturi mixer and the screw conveyor to realize the continuous premixing production. Utility Model Content

[0008] The utility model aims at the deficiencies of the prior art and develops a continuous premixing device which can realize continuous premixing production and replace the traditional intermittent premixing technology. Since the chilled water system is cancelled, the energy consumption of the product is reduced, the continuous premixing realizes real continuous production automation and improves the production efficiency.

[0009] The technical solution to the technical problem solved by the utility model is: a continuous premixing device, comprising a weighing bin, a first screw conveyor, a venturi mixer and a second screw conveyor, wherein the first screw conveyor is provided with a first feed port and a first discharge port, the weighing bin is connected to the first feed port, the venturi mixer is provided with a second feed port, a second discharge port and a liquid inlet, the second feed port is connected to the first discharge port, the liquid inlet is connected with a liquid inlet pipe, the liquid inlet pipe is connected to an external pipeline, sulfuric acid enters the liquid inlet pipe by pumping or gravity, the second screw conveyor is provided with a third feed port and a third discharge port, the third feed port is connected to the second discharge port.

[0010] Preferably, a star-shaped discharger is provided at the bottom of the weighing bin, one end of the star-shaped discharger is connected to the discharge end of the weighing bin, and the other end is connected to the first feed port, and the star-shaped discharger is driven by a reducer.

[0011] Preferably, the first screw conveyor and the second screw conveyor are driven by a servo motor.

[0012] Preferably, an atomizing nozzle is provided at the liquid inlet.

[0013] Preferably, a metering valve is provided on the liquid inlet pipe.

[0014] Preferably, the first screw conveyor and the second screw conveyor are respectively connected to the support, and the support is installed on the ground.

[0015] The effects provided in the utility model content are only the effects of the embodiments, rather than all the effects of the utility model. The above technical solutions have the following advantages or beneficial effects:

[0016] 1. By providing a star-shaped discharge device, it is possible to prevent the ore powder from jamming at the discharge end of the weighing bin, ensuring the continuity of the premixing work;

[0017] 2. By providing an atomizing nozzle at the liquid inlet of the Venturi mixer, sulfuric acid enters the mixer in a circular atomizing spray pattern to form a dispersed sulfuric acid spray mist, increasing the contact area with the ore powder and enabling the sulfuric acid to fully infiltrate the ore powder, thereby improving the mixing efficiency;

[0018] 3. By providing a metering valve on the liquid inlet pipe, it is possible to control the continuous feeding of sulfuric acid according to the set acid-ore ratio;

[0019] 4. The utility model realizes continuous premixing production, replaces the traditional intermittent premixing technology, cancels the chilled water system, reduces the product energy consumption, saves costs and improves the production efficiency at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the front view of the present utility model;

[0021] Figure 2 is Figure 1 the sectional view taken along the line A-A in

[0022] Figure 3 is Figure 2 the partial enlarged view of area A in

[0023] Figure 4 is the right view of the present utility model;

[0024] Figure 5 is the overall structure diagram of the present utility model;

[0025] Figure 6 is the top view of the present utility model.

[0026] Wherein: 1. weighing bin; 2. rotary airlock valve; 21. speed reducer; 3. first screw conveyor; 31. first feed inlet; 32. first discharge outlet; 4. Venturi mixer; 41. second feed inlet; 42. second discharge outlet; 43. liquid inlet; 431. atomizing nozzle; 5. liquid inlet pipe; 51. metering valve; 6. second screw conveyor; 61. third feed inlet; 62. third discharge outlet; 7. servo motor; 8. support. Detailed implementation manners

[0027] In order to clearly illustrate the technical features of this solution, the present utility model will be elaborated in detail below through specific implementation manners and in conjunction with its attached drawings.

[0028] Embodiment 1

[0029] Refer to Figures 1 to 6 , a continuous premixing device, including a weighing bin 1, a first screw conveyor 3, a Venturi mixer 4 and a second screw conveyor 6. A first feed inlet 31 and a first discharge outlet 32 are provided on the first screw conveyor 3. The weighing bin 1 is connected to the first feed inlet 31. A second feed inlet 41, a second discharge outlet 42 and a liquid inlet 43 are provided on the Venturi mixer 4. The second feed inlet 41 is connected to the first discharge outlet 32. A liquid inlet pipe 5 is connected to the liquid inlet 43. The liquid inlet pipe 5 is connected to an external pipeline. Sulfuric acid enters the liquid inlet pipe 5 by pumping or gravity flow. A third feed inlet 61 and a third discharge outlet 62 are provided on the second screw conveyor 6. The third feed inlet 61 is connected to the second discharge outlet 42.

[0030] As Figures 1 to 3 shown, a rotary airlock valve 2 is provided at the bottom of the weighing bin 1. One end of the rotary airlock valve 2 is connected to the discharge end of the weighing bin 1, and the other end is connected to the first feed inlet 31. The rotary airlock valve 2 is driven by a speed reducer 21.

[0031] As Figure 1 and Figure 5 shown, the first screw conveyor 3 and the second screw conveyor 6 are driven by a servo motor 7.

[0032] As Figure 2 and Figure 3 shown, an atomizing nozzle 431 is provided at the liquid inlet 43.

[0033] As Figure 1 and Figure 5 shown, a metering valve 51 is provided on the liquid inlet pipe 5.

[0034] As Figure 1 and Figure 5 shown, the first screw conveyor 3 and the second screw conveyor 6 are respectively connected to a support 8, and the support 8 is installed on the ground.

[0035] Principle and operation process

[0036] By setting the star unloader 2, the utility model can prevent the ore powder from jamming at the discharging end of the weighing bin 1, ensuring the continuity of the premixing work; the liquid inlet 43 of the Venturi mixer 4 is provided with an atomizing nozzle 431. Sulfuric acid enters the mixer in a ring-shaped atomizing spray form to form a dispersed sulfuric acid spray mist, increasing the contact area with the ore powder, enabling the sulfuric acid to fully infiltrate the ore powder, and improving the mixing efficiency; a metering valve 51 is arranged on the liquid inlet pipe 5, which can control the continuous feeding of sulfuric acid according to the set acid-ore ratio; by using the Venturi principle to set the Venturi mixer 4, it can drive the sulfuric acid to enter through the liquid inlet pipe 5 after the ore powder enters, and spray out through the atomizing nozzle 431, and be evenly premixed in the Venturi mixer 4. The sulfuric acid does not require a power device to drive when entering the Venturi mixer 4. Through the above principle, continuous premixed production is realized, replacing the traditional intermittent premixing technology, canceling the chilled water system, greatly reducing the energy consumption of the product, saving costs and improving production efficiency at the same time.

[0037] During use, the ore powder is temporarily stored in the weighing bin 1, enters the first screw conveyor 3 through the star unloader 2, and the first screw conveyor 3 continuously feeds a fixed amount of ore powder into the Venturi mixer 4 according to the acid-ore ratio. At the same time, by controlling the metering valve 51, sulfuric acid also enters the Venturi mixer 4 according to the acid-ore ratio. The ore powder and sulfuric acid are pre-infiltrated and mixed in the Venturi mixer 4. After the mixing of the mixture is completed, it enters the second screw conveyor 6 for further mixing. The length of the second screw conveyor 6 is designed according to the time requirement of material mixing. The material enters the reactor through the pipeline after passing through the third discharge port 62;

[0038] The top of the Venturi mixer 4 can be connected to compressed air by setting an air inlet pipe, or by setting a gas pipe to connect the upper end and the lower end of the Venturi mixer 4, with an air pump arranged in the middle and a filter screen arranged at the lower end gas pipe orifice. Through these two methods, the ore powder can be further boiled and dispersed, further increasing the contact area between the ore powder and sulfuric acid, fully infiltrating and mixing, and at the same time, it can also increase the flow rate of the ore powder and improve the efficiency of inhaling sulfuric acid.

[0039] Concentrated sulfuric acid is used for sulfuric acid, and the fineness requirement of the ore powder is 3%-5% higher than that of the intermittent premixing process.

[0040] Although the specific implementation manners of the present utility model are described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present utility model. Based on the technical solutions of the present utility model, various modifications or deformations that can be made by those skilled in the art without creative efforts still fall within the protection scope of the present utility model.

Claims

1. A continuous premixing device, characterized in that: The invention comprises a weighing bin (1), a first screw conveyor (3), a venturi mixer (4) and a second screw conveyor (6); the first screw conveyor (3) is provided with a first feed port (31) and a first discharge port (32); the weighing bin (1) is connected to the first feed port (31); the venturi mixer (4) is provided with a second feed port (41), a second discharge port (42) and a liquid inlet (43); the second feed port (41) is connected to the first discharge port (32); the liquid inlet (43) is connected to a liquid inlet pipe (5); the second screw conveyor (6) is provided with a third feed port (61) and a third discharge port (62); the third feed port (61) is connected to the second discharge port (42).

2. A continuous premixing device according to claim 1, characterized in that: A star-shaped discharger (2) is provided at the bottom of the weighing bin (1), one end of the star-shaped discharger (2) is connected to the discharge end of the weighing bin (1), and the other end is connected to the first feed port (31), and the star-shaped discharger (2) is driven by a reducer (21).

3. A continuous premixing device according to claim 1, characterized in that: The first screw conveyor (3) and the second screw conveyor (6) are driven by a servo motor (7).

4. A continuous premixing device according to claim 1, characterized in that: An atomizing nozzle (431) is provided at the liquid inlet (43).

5. A continuous premixing device according to claim 1, characterized in that: The liquid inlet pipe (5) is provided with a metering valve (51).

6. A continuous premixing device according to claim 1, characterized in that: The first screw conveyor (3) and the second screw conveyor (6) are respectively connected to a bracket (8), and the bracket (8) is installed on the ground.

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