An apparatus for the production of iron oxide black pigments by the addition process

Abstract

The utility model discloses a device for preparing iron oxide black pigment by addition method, raw materials first enter the impurity removal pool, then pass through the preparation gel device, filter press A, high -speed blender in proper order, then are fully stirred and react through the first reaction kettle and the second reaction kettle and obtain the iron oxide black semi -product, then pass through the vibrating screen machine, filter press B, belt dryer and pulverizer in proper order, and finally obtain the iron oxide black finished product. The device can continuously produce, the reaction of two -stage closed type double -layer heat preservation reaction kettle is more sufficient, reaction time is greatly shortened, and energy consumption is lower, iron black particle is extremely fine, and coloring power is very high, and simultaneously, because of using addition method to produce, the reactant material can use titanium dioxide factory's waste ferrous sulfate or the sulfuric acid production after sulfuric acid, iron mud, the iron slag containing iron and aluminum after smelting aluminum, steel plant pickling waste water, industrial waste material resource utilization, and the discharge meets the environmental protection requirement.

Description

Technical Field

[0001] This utility model relates to the technical field of iron oxide pigment production equipment, specifically an apparatus for preparing iron oxide black pigment by an addition method. Background Technology

[0002] Iron oxide pigments are inorganic pigments primarily composed of iron oxides and their hydrates. They include four basic coloring varieties: iron oxide red, iron oxide yellow, iron oxide black, and iron oxide brown, as well as derivatives such as mica iron oxide (for rust prevention) and magnetic iron oxide (for magnetic recording materials). Over 70% of these pigments are prepared using chemical synthesis methods, resulting in high purity, uniform particle size, and a broad color spectrum. They are also non-toxic and environmentally friendly. Their core performance characteristics include excellent dispersibility, lightfastness (lightfastness rating 6-7), weather resistance (weather resistance rating 5), and UV absorption capacity, making them suitable for 12 industrial sectors, including building materials, coatings, plastics, and electronics.

[0003] Traditional equipment for producing iron oxide black pigment is not only time-consuming (reaction time requires 9-10 hours), consumes a large amount of steam (5.5-6 tons of steam per ton of product), and generates significant wastewater, but also has room for improvement in product yield and quality. With the surge in global demand for iron oxide pigment and the requirements for high-quality development, innovating a production line that is energy-efficient, has a short reaction time, is environmentally friendly, and produces stable product quality has become crucial. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an apparatus for preparing iron oxide black pigment using an addition method. The raw material first enters a purification tank, then sequentially passes through a gel preparation device, a filter press A, and a high-speed mixer. Next, it undergoes thorough stirring and reaction in a first and second reaction vessel to obtain a semi-finished iron oxide black product. This semi-finished product then sequentially passes through a vibrating screen, a filter press B, a belt dryer, and a pulverizer to finally obtain the finished iron oxide black product. This apparatus allows for continuous production. The two-stage, sealed, double-layered, insulated reaction vessel ensures thorough reaction, significantly shortening the reaction time, reducing energy consumption, producing extremely fine iron oxide black particles with high tinting strength. Furthermore, because the addition method is used, the reactants can utilize ferrous sulfate waste from titanium dioxide plants, pyrite slag from sulfuric acid production from pyrite, iron sludge, iron-aluminum slag discharged after aluminum smelting, and pickling wastewater from steel plants. This resource utilization of industrial waste ensures that emissions meet environmental protection requirements.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] An apparatus for preparing iron oxide black pigment by addition reaction involves the following steps: the raw material first enters a purification tank, then passes through a gel preparation device, a filter press A, and a high-speed mixer in sequence, followed by a thorough stirring reaction in a first reaction vessel and a second reaction vessel to obtain a semi-finished iron oxide black product, which then passes through a vibrating screen, a filter press B, a belt dryer, and a pulverizer in sequence to finally obtain the finished iron oxide black product.

[0007] The impurity removal tank includes a raw material feed pipe, a dilute sulfuric acid inlet pipe, a silt and debris discharge outlet, a drive motor A, a baffle plate A, and a stirring paddle A. After the waste containing ferrous sulfate is put into the impurity removal tank, steam is introduced, and then appropriate amounts of water, sulfuric acid, and iron powder are added according to the solution concentration. The mixture is thoroughly stirred and precipitated to remove titanium and other silt and debris contained in the waste, resulting in a ferrous sulfate solution with a pH value of 4 to 4.5. The clarified ferrous sulfate solution is then pumped into a pH concentration stirring tank.

[0008] The gel preparation apparatus includes a pH concentration stirring tank, a liquid alkali tank, and a gel preparation tank. Both the pH concentration stirring tank and the gel preparation tank have built-in stirring devices and external drive motors connected to a power control switch. In the pH concentration stirring tank, ferrous sulfate solution and liquid alkali (28-32% NaOH aqueous solution by mass) are thoroughly stirred to adjust the pH concentration of the ferrous sulfate solution to 8.5-9. The adjusted ferrous sulfate solution is then pumped into the gel preparation tank. The gel preparation tank is stirred thoroughly at room temperature to obtain Fe(OH)₂ gel. This gel is then pumped into a filter press A for dehydration to obtain a dry gel. The dry gel is then pumped into a high-speed mixer to mix with the dispersed iron sludge. Dehydration is performed to accelerate the reaction rate.

[0009] The iron sludge containing ferric ions is first dispersed by high-speed mixing in a high-speed mixer for 30-40 minutes at a speed of ≥1000 rpm. Then, the dry gel is pumped in and mixed for 15-20 minutes to obtain a uniform and viscous paste. The viscous paste is then pumped into the first reaction vessel for reaction. The high-speed mixing of the iron sludge and dry gel beforehand is to further accelerate the reaction rate and shorten the reaction time when reacting with additives in the first reaction vessel.

[0010] The first and second reaction vessels have the same structure, both being double-layered sealed and insulated structures. The top of the vessel body is equipped with a reactant inlet, a steam inlet, and a vent outlet, while the bottom of the vessel body is equipped with a discharge outlet. The vessel body jacket has a steam channel, and the lower part of the jacket has a condensate drain outlet. Several baffles B are evenly distributed on the inner wall of the vessel body. The vessel body is wrapped with insulation cotton. Several reactant inlets are provided for adding raw materials prepared in the previous process, additives, sensors, or an appropriate amount of water.

[0011] The double-layered sealed insulation structure of the reactor ensures that steam, after entering the jacket, remains in a sealed space and envelops the inner layer of the reactor. This allows the temperature of the stirred material inside the reactor to rise rapidly and remain constant once the designated temperature is reached, resulting in fast heating, high temperature uniformity, and low energy consumption. A flow meter and a check valve are installed at the steam inlet connection for real-time monitoring of the injected steam volume. A pressure relief valve and a manual venting pipe are installed at the exhaust port connection. This allows for automatic or manual venting of steam from the jacket when the reactor is under maintenance or when the steam pressure is too high, quickly reducing the reactor temperature, facilitating maintenance, and ensuring safety and reliability. A condensate drain outlet is used to drain condensate deposited at the bottom of the jacket. Baffles help reduce laminar flow and increase turbulence during material mixing, resulting in better mixing. The insulation cotton wrapped around the reactor exterior prevents heat loss from the reactor interior.

[0012] A flow meter and a one-way valve are also installed at the connection point where the iron sludge and dry gel are mixed and stirred before being injected into the first reactor. The flow meter is used to accurately measure and monitor the total content of iron sludge and Fe(OH)2 gel added to the reactor in real time. Several sensors are included, such as a temperature sensor, a pH sensor, and a level sensor, which are used to monitor the temperature, pH value, and liquid level of the reactants in the reactor in real time. The temperature and pH sensors are inserted and fixed to the bottom of the reactor's inner wall, near the baffle, to ensure more accurate and effective temperature and pH measurements. The level sensor is inserted and fixed to the top of the reactor's inner wall, near the baffle. The sensors transmit the temperature and level signals to the controller, which contains a chip to automatically control the steam valve and liquid pump.

[0013] The first and second reaction vessels are thoroughly stirred by agitator B to obtain iron oxide black semi-finished product. Agitator B is located at the lower part of the drive shaft, which passes through the center of the top of the vessel and is connected to drive motor B. Drive motor B is connected to a power control switch to provide power to the drive shaft. The blades of agitator B are propeller-type, which thoroughly stirs the materials, ensuring complete reaction and significantly shortening the reaction cycle. The first reaction vessel is operated at a temperature of 90–95℃ for approximately 1–1.5 hours; the second reaction vessel is operated at a temperature of approximately 135–140℃ for approximately 2.5–3 hours.

[0014] The vibrating screen is used to vibrate and screen the iron oxide black semi-finished product obtained from the reaction in the second reactor, and to screen out iron black particles of the required size. The screen used is 250 mesh.

[0015] Filter press B is used to wash the iron oxide black semi-finished product obtained after screening by the vibrating screen with clean water. The washed iron oxide black semi-finished product contains 30% water.

[0016] The belt dryer dries the iron oxide black semi-finished product after cleaning the filter press B, and the moisture content after drying is <1%.

[0017] The pulverizer pulverizes the semi-finished iron oxide black product dried by the belt dryer, and finally obtains the finished iron oxide black product with extremely fine particles and high coloring power.

[0018] Advantages of utility models:

[0019] 1. Compared with the production equipment used in traditional processes, this utility model not only greatly shortens the reaction time, but also has low energy consumption, high product quality, and a certain increase in output: the reaction time of the equipment used in traditional processes is 9 to 10 hours, while this utility model only requires 3.5 to 4.5 hours; the traditional process consumes 5.5 to 6 tons of steam per ton of iron oxide pigment, while this utility model consumes only 3 to 3.5 tons of steam per ton of iron oxide pigment; this utility model can make the additives and raw materials in the reaction vessel react fully, and the iron black particles obtained after pulverization are finer and have higher coloring power, and the output is also increased to a certain extent, greatly improving economic benefits.

[0020] 2. This utility model adopts an addition method for production, which is more economical and environmentally friendly: First, the reactants of this utility model can use ferrous sulfate waste from titanium dioxide plants, pyrite slag after sulfuric acid production from pyrite, iron sludge, iron-aluminum slag discharged after aluminum smelting, and pickling wastewater from steel plants, thus making resource utilization of industrial waste and reducing raw material costs; Second, the wastewater discharge of traditional processes is 30-35 tons per ton of product, while the wastewater discharge of this utility model is only 25-26 tons per ton of product, greatly reducing wastewater discharge; Third, the process of this utility model is reasonable, and the discharge of waste gas, wastewater, and solid waste basically meets environmental protection requirements.

[0021] 3. The reaction vessel of this utility model can be used to produce iron oxide black or iron oxide red, and the equipment has a wide range of applications.

[0022] 4. The reactor of this utility model is equipped with multiple feed inlets, making it convenient and quick to add materials and place sensors.

[0023] 5. The sensor of this utility model transmits temperature and liquid level signals to the controller, which is equipped with a chip to realize automatic control of steam valves and liquid pumps. Attached Figure Description

[0024] Figure 1 This is a plan view of the device of this utility model;

[0025] Figure 2 This is a schematic diagram of the structure of the first reaction vessel of this utility model;

[0026] Figure 3 This is a top view of the first reaction vessel of this utility model;

[0027] Figure 4This is a schematic diagram of the operation process of the first reaction vessel of this utility model;

[0028] The numbers and component names in the diagram are as follows: 1-Impuring tank; 111-Raw material feed pipe; 112-Dilute sulfuric acid inlet pipe; 113-Sediment and debris discharge outlet; 114-Drive motor A; 115-Baffle plate A; 116-Agitator A; 117-Pump; 2-Gel preparation device; 21-pH concentration adjustment stirring tank; 22-Liquid alkali tank; 23-Gel preparation tank; 3-Filter press A; 4-High-speed mixer; 5-First reaction vessel ; 51-Drive motor B; 52-Reactant inlet; 53-Steam inlet; 54-Insulation cotton; 55-Drive shaft; 56-Agitator B; 57-Baffle plate B; 58-Steam passage; 59-Exhaust gas outlet; 510-Discharge outlet; 511-Condensate drain outlet; 512-Tank body; 6-Second reaction vessel; 7-Vibrating screen; 8-Filter press B; 9-Belt dryer; 10-Pulverizer; 11-Iron oxide black finished product. Detailed Implementation

[0029] Example 1

[0030] An apparatus for preparing iron oxide black pigment by addition reaction involves the following steps: the raw material first enters a purification tank 1, then passes through a gel preparation device 2, a filter press A3, and a high-speed mixer 4 in sequence, followed by a first reaction vessel 5 and a second reaction vessel 6 for thorough stirring and reaction to obtain iron oxide black semi-finished product, and then passes through a vibrating screen 7, a filter press B8, a belt dryer 9, and a pulverizer 10 in sequence to finally obtain iron oxide black finished product 11.

[0031] The impurity removal tank 1 includes a raw material feed pipe 111, a dilute sulfuric acid inlet pipe 112, a mud and debris discharge outlet 113, a drive motor A114, a baffle plate A115, and a stirring paddle A116. After the waste containing ferrous sulfate is put into the impurity removal tank 1, steam is introduced, and then appropriate amounts of water, sulfuric acid, and iron powder are added according to the solution concentration. The mixture is stirred and precipitated to obtain a ferrous sulfate solution with the required pH concentration. The clarified ferrous sulfate solution is then pumped into the pH concentration stirring tank 21 by a pump 117.

[0032] The gel preparation device 2 includes a pH concentration stirring tank 21, a liquid alkali tank 22, and a gel preparation tank 23. The pH concentration stirring tank 21 and the gel preparation tank 23 are equipped with internal stirring devices and external drive motors for stirring. The pH concentration stirring tank 21 is used to thoroughly stir ferrous sulfate solution and liquid alkali to obtain the required pH concentration. Then, the adjusted ferrous sulfate solution is pumped into the gel preparation tank 23 by a pump 117. The gel preparation tank 23 is stirred to obtain ferrous hydroxide gel. The gel is then pumped into a filter press A3 by a pump 117 to remove water and obtain dry gel. Finally, the dry gel is pumped into a high-speed mixer 4 by a pump 117 to mix with the stirred and dispersed iron sludge.

[0033] The high-speed mixer 4 first disperses the iron mud containing ferric ions by high-speed stirring, then pumps in the dry gel for mixing and stirring to obtain a uniform and viscous paste, and then pumps the viscous paste into the first reaction vessel 5 for reaction by pump 117.

[0034] The first reactor 5 and the second reactor 6 have the same structure, both being double-layered sealed heat-insulating structures. The top of the reactor body 512 is provided with a reactant inlet 52, a steam inlet 53, and a vent 59. The bottom of the reactor body 512 is provided with a discharge outlet 510. The interlayer of the reactor body 512 is provided with a steam channel 58, and the lower part of the interlayer is provided with a condensate drain outlet 511. Several baffles B57 are evenly distributed on the inner wall of the reactor body 512. The reactor body 512 is wrapped with heat-insulating cotton 54. Several reactant inlets 52 are provided.

[0035] The first reactor 5 and the second reactor 6 are stirred and reacted by a stirring paddle B56 to obtain iron oxide black semi-finished product; the stirring paddle B56 is arranged at the lower part of the drive shaft 55, and the upper part of the drive shaft 55 passes through the center of the top of the reactor body 512 and is connected to the drive motor B51.

[0036] The vibrating screen 7 is used to vibrate and screen the iron oxide black semi-finished product obtained from the reaction in the second reaction vessel 6.

[0037] The filter press B8 is used to wash the iron oxide black semi-finished product obtained after screening by the vibrating screener 7 with clean water.

[0038] The belt dryer 9 dries the iron oxide black semi-finished product after it has been cleaned by the filter press B8.

[0039] The pulverizer 10 pulverizes the iron oxide black semi-finished product dried by the belt dryer 9, and finally obtains the iron oxide black finished product 11.

[0040] The production process of this embodiment is as follows: First, the raw materials are cleaned of impurities, gel is prepared, water is removed by pressure filtration, and iron mud is dispersed. Then, the iron oxide black semi-finished product is obtained by fully stirring and reacting in a two-stage closed double-layer heat-insulated reactor. After vibration screening, pressure filtration and cleaning, drying and pulverization are carried out in sequence, and finally the iron oxide black finished product is obtained.

Claims

1. An apparatus for preparing iron oxide black pigment by an addition method, characterized in that, It includes a cleaning tank (1), a gel preparation device (2), a filter press A (3), a high-speed mixer (4), a first reaction vessel (5), a second reaction vessel (6), a vibrating screen (7), a filter press B (8), a belt dryer (9), and a pulverizer (10). The supernatant outlet of the impurity removal tank (1) is connected to the feed end of the gel preparation device (2) via a pump (117); The discharge end of the gel preparation device (2) is connected to the feed end of the filter press A (3) via a pump (117); The discharge end of the filter press A (3) is connected to the feed end of the high-speed mixer (4) via a pump (117); The discharge end of the high-speed mixer (4) is connected to the feed end of the first reactor (5) via a pump (117); The discharge end of the first reactor (5) is connected to the feed end of the second reactor (6); The discharge end of the second reactor (6) is connected in sequence to the vibrating screen (7), filter press B (8), belt dryer (9) and pulverizer (10) along the material flow direction.

2. The apparatus for preparing iron oxide black pigment by addition method according to claim 1, characterized in that, The impurity removal tank (1) is equipped with a raw material feed pipe (111), a dilute sulfuric acid inlet pipe (112), a mud and debris discharge outlet (113), a drive motor A (114), a baffle plate A (115), and a stirring paddle A (116). The output end of the drive motor A (114) is connected to the stirring paddle A (116), and the stirring paddle A (116) extends into the interior of the impurity removal tank (1); The baffle plate A (115) is fixedly arranged on the inner wall of the impurity removal tank (1).

3. The apparatus for preparing iron oxide black pigment by addition method according to claim 1, characterized in that, The gel preparation apparatus (2) includes a pH concentration stirring tank (21), a liquid alkali tank (22), and a gel preparation tank (23). Both the pH concentration adjustment stirring tank (21) and the gel preparation tank (23) are equipped with stirring components, and both are equipped with drive motors to drive the stirring components. The outlet of the liquid alkali tank (22) is connected to the inlet of the pH concentration adjusting stirring tank (21); The inlet of the pH concentration adjustment stirring tank (21) is connected to the pump (117) at the output end of the impurity removal tank (1), and the outlet of the pH concentration adjustment stirring tank (21) is connected to the inlet of the gel preparation tank (23) through the pump (117). The outlet of the gel preparation tank (23) is connected to the inlet of the filter press A (3) via a pump (117).

4. The apparatus for preparing iron oxide black pigment by addition method according to claim 1, characterized in that, The high-speed mixer (4) has a mixing speed of ≥1000r / min; the high-speed mixer (4) is provided with at least two feed inlets, which correspond to the discharge end of the filter press A (3) and the iron sludge feed pipe, respectively.

5. The apparatus for preparing iron oxide black pigment by addition method according to claim 1, characterized in that, The first reactor (5) and the second reactor (6) have the same structure, both being double-layer sealed heat-insulating structures, including a reactor body (512), a drive motor B (51), a transmission shaft (55), and a stirring paddle B (56). The top of the vessel body (512) is provided with several reactant inlets (52), steam inlets (53) and exhaust gas outlets (59), and the bottom of the vessel body (512) is provided with an outlet (510). The interlayer of the vessel body (512) is a steam channel (58), and a condensate drain outlet (511) is provided at the bottom of the interlayer. The inner wall of the vessel body (512) is fixedly provided with several baffles B (57), and the outer side of the vessel body (512) is wrapped with heat insulation cotton (54). The drive motor B (51) is installed at the top center of the vessel body (512). The output end of the drive motor B (51) is connected to the transmission shaft (55). The transmission shaft (55) extends downward into the interior of the vessel body (512). The stirring paddle B (56) is installed at the lower part of the transmission shaft (55).

6. The apparatus for preparing iron oxide black pigment by addition method according to claim 5, characterized in that, A flow meter and a check valve are installed on the pipeline of the steam inlet (53); a pressure relief valve and a manual exhaust pipe are installed on the pipeline of the exhaust port (59); A flow meter and a check valve are installed on the connecting pipe between the reactant inlet (52) of the first reactor (5) and the discharge end of the high-speed mixer (4).

7. The apparatus for preparing iron oxide black pigment by addition method according to claim 1, characterized in that, The vibrating screen (7) is equipped with a 250-mesh screen.

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