An apparatus for preparing iron oxide red pigments by phase inversion

Abstract

A kind of device for preparing iron oxide red pigment with phase inversion method, raw materials first enter impurity removal pool, then pass through seed barrel, then iron mud after being stirred and dispersed with high-speed mixer is together into reaction kettle to obtain iron oxide red semi-finished product, then pass through vibrating screen machine, filter press, belt dryer and pulverizer in turn, finally obtain iron oxide red finished product.The device can produce continuously, the reaction of double-layer insulation reaction kettle is more sufficient, the reaction time is greatly shortened, and the energy consumption is lower, the iron red particle is extremely fine, the tinting strength is very high;At the same time, since the production is carried out by using phase inversion method, the reaction material can use titanium dioxide factory waste ferrous sulfate or pyrite slag after producing sulfuric acid, iron mud, discharged iron-containing aluminum slag after aluminum smelting, steel plant pickling wastewater, industrial waste resource utilization, discharge meets the requirements of environmental protection.

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 red pigment using a phase inversion 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 red pigment is not only time-consuming, consumes a lot of steam, and generates a large amount of wastewater, but also has room for improvement in product output and quality. With the surge in global demand for iron oxide pigment and the requirements for high-quality development, it has become crucial to innovate a production line that is energy-efficient, has a short reaction time, is environmentally friendly, and produces stable product quality. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an apparatus for preparing iron oxide red pigment using a phase inversion method. The raw materials first enter a purification tank, then pass through a seed tank, and are subsequently added to a reaction vessel along with iron sludge dispersed by a high-speed mixer to obtain a semi-finished iron oxide red product. This semi-finished product then passes through a vibrating screen, a filter press, a belt dryer, and a pulverizer in sequence to finally obtain the finished iron oxide red product. This apparatus allows for continuous production. The sealed, double-layered, insulated reaction vessel ensures thorough reaction, significantly shortens reaction time, and reduces energy consumption. It also produces extremely fine iron oxide red particles with high tinting strength. Furthermore, because the phase inversion 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 from 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 red pigment using a phase inversion method is described. The raw material first enters a purification tank, then passes through a seed tank, and is then fed into a reaction vessel along with iron sludge that has been dispersed by a high-speed mixer to obtain iron oxide red semi-finished product. The semi-finished product is then passed through a vibrating screen, a filter press, a belt dryer, and a pulverizer in sequence to finally obtain the finished iron oxide red 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 of 4 to 4.5. The clarified ferrous sulfate solution is then pumped into a seed crystal tank.

[0008] Several crisscrossing gas distribution pipes with vent holes are evenly distributed at the bottom of the seed crystal container, and the gas distribution pipes are connected to a Roots blower. An appropriate amount of liquid alkali (NaOH aqueous solution with a mass content of 28-32%) is added to the clarified ferrous sulfate solution in the seed crystal container, and air is introduced for 45-60 minutes to react, preparing seed crystals with a pH of 10-11. The air introduction rate is 1-2 m³ / min, and then the seed crystals are pumped into the reaction vessel using a pump.

[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 r / min, resulting in a uniform and viscous paste. This paste is then pumped into a reaction vessel for further reaction. The high-speed mixing of the iron sludge beforehand ensures uniform dispersion, further accelerating the reaction rate and shortening the reaction time when it reacts with other materials in the reaction vessel.

[0010] The reactor has a double-layered sealed insulation structure. The top of the reactor body is provided with a reactant inlet, a steam inlet, and a vent outlet. The bottom of the reactor body is provided with a discharge outlet. The reactor body jacket is provided with a steam channel, and the lower part of the jacket is provided with a condensate drain outlet. Several baffles B are evenly distributed on the inner wall of the reactor body. The reactor body is wrapped with insulation cotton. There are several reactant inlets.

[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 one-way valve are installed at the steam inlet connection for real-time monitoring of the steam flow. A pressure relief valve and a manual venting pipe are installed at the exhaust port connection 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. Several reactant inlets can be used to add reactants such as iron sludge, seed crystals, catalysts, additives, and appropriate amounts of water, or to insert sensors. The catalyst is a ferrous sulfate solution with a concentration of 28-30 g / 100 ml.

[0012] Flow meters and check valves are installed at the connection points where iron sludge and seed crystals are pumped into the reactor. The flow meters are used to accurately measure and monitor the content of iron sludge and seed crystals added to the reactor in real time. Several sensors are included, such as temperature sensors, pH sensors, and level sensors, 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 valves and liquid pumps.

[0013] The reaction vessel is heated to approximately 130–140°C, where iron sludge, seed crystals, catalyst, additives, and a suitable amount of water are thoroughly stirred and reacted. After approximately 2.5–3 hours, a semi-finished product of iron oxide red is obtained. A stirring paddle B is positioned below the drive shaft, which passes through the center of the top of the vessel and connects to a drive motor B. The drive motor B is connected to a power control switch to provide power to the drive shaft. The blades of the stirring paddle B are propeller-type, ensuring thorough stirring of the materials and allowing for complete reaction, thus significantly shortening the reaction cycle.

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

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

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

[0017] The pulverizer pulverizes the iron oxide red semi-finished product dried by the belt dryer, and finally obtains the iron oxide red finished 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 2.5 to 3 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 oxide red 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 a phase transformation method for production, which is more economical and environmentally friendly: First, the reaction materials of this utility model can be 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 reactor structure of this utility model;

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

[0027] Figure 4 This is a schematic diagram of the operation process of the 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-Mud and debris discharge outlet; 114-Drive motor A; 115-Baffle plate A; 116-Agitator A; 117-Pump; 2-Seed tank; 21-Roots blower; 22-Gas distribution pipe; 3-High-speed mixer; 4-Reaction vessel; 41-Drive motor B; 42-Reactant feed inlet; 43-Steam inlet; 44-Insulation cotton; 45-Drive shaft; 46-Agitator B; 47-Baffle plate B; 48-Steam passage; 49-Exhaust gas outlet; 410-Discharge outlet; 411-Condensate drain outlet; 412-Vessel body; 5-Vibrating screen; 6-Filter press; 7-Belt dryer; 8-Pulverizer; 9-Iron oxide red finished product. Detailed Implementation

[0029] Example 1

[0030] An apparatus for preparing iron oxide red pigment by phase inversion method: the raw material first enters the impurity removal tank 1, then passes through the seed tank 2, and is then fed into the reaction vessel 4 along with the iron sludge after being stirred and dispersed by the high-speed mixer 3 to obtain iron oxide red semi-finished product. After passing through the vibrating screen 5, the filter press 6, the belt dryer 7 and the pulverizer 8 in sequence, the final iron oxide red finished product 9 is obtained.

[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 seed tank 2 through a pump 117.

[0032] The bottom of the seed tank 2 is evenly distributed with several crisscrossing gas distribution pipes 22, and the gas distribution pipes 22 are provided with several air holes. The gas distribution pipes 22 are connected to the Roots blower 2). An appropriate amount of liquid alkali is added to the clarified ferrous sulfate solution in the seed tank, and air is introduced for a certain period of time to prepare the seed crystal. The seed crystal is then pumped into the reaction vessel 4 by the pump 117.

[0033] The high-speed mixer 4 first disperses the iron sludge containing ferric ions by high-speed stirring to obtain a uniform and viscous paste, and then pumps the viscous paste into the reaction vessel 4 through the pump 117.

[0034] The reactor 4 is a double-layered sealed heat-insulating structure. The top of the reactor body 412 is provided with a reactant inlet 42, a steam inlet 43, and a vent 49. The bottom of the reactor body 412 is provided with a discharge outlet 410. The interlayer of the reactor body 412 is provided with a steam channel 48, and the lower part of the interlayer is provided with a condensate drain outlet 411. Several baffles B47 are evenly distributed on the inner wall of the reactor body 412. The reactor body 412 is wrapped with heat-insulating cotton 44. Several reactant inlets 42 are provided. The reactor is used to fully stir and react the reactants to obtain iron oxide red semi-finished product by stirring the agitator B46. The agitator B46 is arranged at the lower part of the drive shaft 45, and the upper part of the drive shaft 45 passes through the center of the top of the reactor body 412 and is connected to the drive motor B41.

[0035] The vibrating screen 5 is used to vibrate and screen the iron oxide red semi-finished product obtained from the reaction in the reactor 4.

[0036] The filter press 6 is used to wash the iron oxide red semi-finished product obtained after screening by the vibrating screen 5 with clean water.

[0037] The belt dryer 7 dries the iron oxide red semi-finished product after it has been cleaned by the filter press 6.

[0038] The pulverizer 8 pulverizes the iron oxide red semi-finished product dried by the belt dryer 7, and finally obtains the iron oxide red finished product 9.

[0039] The production process in this embodiment is as follows: First, the raw materials are cleaned of impurities, seed crystals are prepared, and iron mud is dispersed. Then, the iron oxide red semi-finished product is obtained by fully stirring and reacting in a 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 red finished product is obtained.

Claims

1. An apparatus for preparing iron oxide red pigment by phase inversion, characterized in that, It includes a purification tank (1), a seed tank (2), a high-speed mixer (3), a reaction vessel (4), a vibrating screen (5), a filter press (6), a belt dryer (7), and a pulverizer (8); The supernatant outlet of the impurity removal tank (1) is connected to the inlet of the seed tank (2) via a pump (117); The discharge end of the high-speed mixer (3) is connected to the feed end of the reactor (4) via a pump (117); The discharge end of the seed tank (2) is connected to the feed end of the reactor (4) via a pump (117); The discharge end of the reactor (4) is connected in sequence to the vibrating screen (5), filter press (6), belt dryer (7) and pulverizer (8) along the material flow direction.

2. The apparatus for preparing iron oxide red pigment by phase inversion 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 drive motor A (114) is connected to the stirring paddle A (116), and the baffle plate A (115) is arranged on the inner wall of the impurity removal tank (1).

3. The apparatus for preparing iron oxide red pigment by phase inversion according to claim 1, characterized in that, The seed tank (2) is equipped with a Roots blower (21). The bottom of the seed tank (2) is provided with crisscrossing air distribution pipes (22). Several air holes are opened on the air distribution pipes (22). The air distribution pipes (22) are connected to the air outlet of the Roots blower (21).

4. The apparatus for preparing iron oxide red pigment by phase inversion according to claim 1, characterized in that, The reactor (4) is a double-layer sealed heat-insulating structure, including a reactor body (412), a drive motor B (41), a transmission shaft (45), and a stirring paddle B (46). The top of the vessel body (412) is provided with several reactant inlets (42), steam inlets (43) and exhaust gas outlets (49), and the bottom of the vessel body (412) is provided with an outlet (410). The interlayer of the vessel body (412) is a steam channel (48), and a condensate drain outlet (411) is provided at the bottom of the interlayer. The inner wall of the vessel body (412) is provided with several baffles B (47), and the outer side of the vessel body (412) is wrapped with heat insulation cotton (44). The drive motor B (41) is installed at the top center of the vessel body (412). The output end of the drive motor B (41) is connected to the transmission shaft (45). The transmission shaft (45) extends downward into the interior of the vessel body (412). The stirring paddle B (46) is installed at the lower part of the transmission shaft (45).

5. The apparatus for preparing iron oxide red pigment by phase inversion according to claim 4, characterized in that, A flow meter and a check valve are installed on the pipeline of the steam inlet (43); a pressure relief valve and a manual exhaust pipe are installed on the pipeline of the exhaust port (49).

6. The apparatus for preparing iron oxide red pigment by phase inversion according to claim 1, characterized in that, The vibrating screen (5) is equipped with a 250-mesh screen.

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