A device for preparing high-activity milk of lime from quicklime

Abstract

The utility model discloses a device is prepared with quicklime high activity lime milk, belongs to mineral processing auxiliary equipment technical field, solved the lime milk that traditional preparation device prepared because of low activity, many impurities, the problem of the insufficient potential control precision of poor stability, the utility model discloses a storage hopper, feeder, digestion mixing tank, deslagging chute, storage mixing tank are connected in proper order along the material flow direction, digestion mixing tank is equipped with the jacket cooling system, promotes the stirring mechanism, temperature sensor, slurry discharge, and deslagging chute is set up obliquely, and the double -deck vibrating screen is equipped in the tank, and the storage mixing tank is equipped with double -deck anti -settling stirring paddle and on -line concentration monitoring meter, the utility model discloses through optimizing digestion reaction temperature field, intensifies the separation of impurity and anti -settling storage design, solves the lime milk that traditional preparation device prepared because of low activity, many impurities, the insufficient potential control precision of poor stability problem, provides high -quality special lime milk for lead zinc mine potential control flotation.

Description

Technical Field

[0001] This utility model belongs to the technical field of mineral processing auxiliary equipment, specifically relating to an apparatus for preparing highly active lime slurry from quicklime. Background Technology

[0002] In lead-zinc ore flotation, pulp potential is a core parameter controlling the redox state of mineral surfaces and influencing the interaction between collectors and minerals. Lime slurry (mainly composed of Ca(OH)2), as a pH adjuster and potential regulator, directly affects flotation efficiency and product quality due to its activity (effective CaO content, specific surface area) and impurity content (such as SiO2, Al2O3, Fe2O3). Traditional lime slurry preparation equipment suffers from the following prominent problems: 1. Quicklime reacts violently with water and releases heat (ΔH≈-65kJ / mol). Traditional digestion devices are prone to local high temperatures (>100℃), resulting in coarse Ca(OH)2 crystals (>50μm), small specific surface area (<20m² / g), and reduced activity (<300ml), making it impossible to effectively adsorb onto the mineral surface to regulate the potential. At the same time, undigested CaO particles remain when the reaction is incomplete, which can easily clog the lime slurry addition pipeline, causing unstable addition. 2. Quicklime raw materials contain impurities such as aluminosilicates and iron oxides. Traditional equipment lacks efficient impurity removal units. Impurities enter the flotation system with the slurry, causing fluctuations in slurry potential (deviation > ±30mV) and reducing separation accuracy. 3. Ca(OH)2 particles are easy to settle. Traditional storage tanks do not have anti-settling design. After 24 hours, the bottom concentration deviation can reach ±15%, and the discharge concentration fluctuates greatly, which cannot meet the potential control requirements of continuous flotation pulp supply.

[0003] Therefore, there is an urgent need for a lime slurry preparation device optimized for potential control requirements, to achieve the production of lime slurry with high activity, low impurities, and stable storage, and to ensure precise and controllable potential during the flotation process. Utility Model Content

[0004] The purpose of this invention is to provide an apparatus for preparing highly active lime slurry from quicklime, so as to solve the problem of insufficient potential control precision caused by low activity, many impurities, and poor stability of lime slurry prepared by traditional preparation apparatus.

[0005] The technical solution of this utility model is as follows: an apparatus for preparing highly active lime slurry from quicklime, comprising a storage hopper, a feeder, a digestion and mixing tank, a slag removal chute, and a storage and mixing tank connected in sequence. The digestion and mixing tank is a circular steel tank with an upper column and a lower cone. A cooling water jacket is installed inside the side wall of the tank, and the cooling water jacket is connected to a drain outlet and a first water inlet. A lifting and mixing mechanism is installed inside the tank, which consists of a porous circulation cylinder and a lifting and mixing paddle. A slurry discharge outlet is provided at the top of the digestion and mixing tank, and a slag discharge outlet is provided at the bottom of the digestion and mixing tank. The slag removal chute is inclined and connected to the slurry discharge outlet. A double-layer vibrating screen is provided in the middle of the slag removal chute, and a vibrator is provided below the double-layer vibrating screen. The storage and mixing tank is a vertical cylindrical steel tank, and a high-efficiency circulation tank is provided inside the tank. A double-layer anti-sinking mixing paddle is provided at the bottom of the high-efficiency circulation tank. The upper layer of the double-layer anti-sinking mixing paddle is axial flow type, and the lower layer is anchor type. A second water inlet is provided on the storage and mixing tank, and a conveying pump is also connected to the bottom of the storage and mixing tank.

[0006] As a further improvement of this utility model, the upper part of the storage hopper is a cube, the lower part is a square pyramid, the cone angle of the discharge port is ≥60°, the discharge port is equipped with an electro-hydraulic regulating valve, and a dust collection hood connected to a bag filter is provided above the storage hopper.

[0007] As a further improvement of this utility model, the feeder is a variable frequency quantitative closed screw feeder with an adjustable conveying capacity of 150-600 kg / h and an error of ≤±1.2%.

[0008] As a further improvement of this utility model, the top of the digestion mixing tank is equipped with a dust collection hood connected to a bag filter, the digestion mixing tank is also equipped with a temperature sensor, and the bottom slag discharge port of the digestion mixing tank is connected to a spiral slag remover and a slag hopper.

[0009] As a further improvement of this utility model, the inclination angle of the upper discharge port 37 of the slag removal chute and the digestion stirring tank is 20-25°, and the upper mesh of the double-layer vibrating screen in the slag removal chute is 100 mesh and the lower mesh is 200 mesh.

[0010] As a further improvement of this utility model, an online concentration monitoring meter is provided on the storage and stirring tank.

[0011] As a further improvement of this utility model, the feeder, digestion mixing tank and storage mixing tank are connected by a PLC.

[0012] The beneficial effects of this utility model are as follows: This invention features an optimized temperature-controlled digestion, efficient slag removal, and anti-precipitation storage unit designed specifically for the characteristics of quicklime. It is suitable for the continuous production of highly active, low-impurity, and highly stable lime slurry using quicklime (CaO) as raw material, meeting the precise control requirements of the slurry potential during flotation. The lime slurry prepared by this invention exhibits high activity (specific surface area ≥30m² / g), low impurities (SiO2 <0.3%), and long-term stability. It can precisely control the slurry potential in lead-zinc ore flotation, increasing metal recovery by 2%–3%, demonstrating significant economic benefits and industrial application value.

[0013] This utility model also has the following beneficial effects: 1. High activity guarantee: The digestion stirring tank is cooled by a cooling jacket to control the reaction temperature at 85-95℃. Combined with enhanced stirring and circulation, the average particle size of Ca(OH)2 is ≤20μm and the specific surface area is ≥35m² / g (more than 50% higher than traditional devices), significantly improving the activity and enabling precise adsorption on the mineral surface to regulate the potential. 2. Low impurity content: The double-layer vibrating screen (100+200 mesh) of the slag removal chute works in synergy with the double spiral slag remover to remove more than 98% of undigested CaO particles and silicon-aluminum impurities. The SiO2 content in the finished product is <0.2% (far below the upper limit of 0.5% required for flotation potential control), reducing interference with the slurry potential. 3. Long-term stable storage: The double-layer anti-sinking stirring of the storage mixing tank and the online concentration monitoring meter ensure that the concentration deviation of the slurry after 24 hours of settling is <±0.5%, ensuring the stable activity of the discharged Ca(OH)2. Combined with the adjustable flow design of the delivery pump, it ensures that the slurry potential fluctuation during the flotation process is <±15mV (the fluctuation of traditional equipment is >±30mV), thus ensuring the stability of the flotation potential. 4. Safe and efficient: The feeder, temperature sensor, concentration meter, and PLC are linked to achieve full automation of the entire process from feeding, digestion, slag removal to storage, reducing manual intervention and improving production efficiency. The exothermic reaction of quicklime digestion is controlled by cooling the cooling jacket to avoid overheating and clumping; quantitative feeding and automatic water replenishment are linked to achieve continuous production and reduce the intensity of manual intervention. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a cross-sectional view of the internal structure of the digester mixing tank; Figure 3 This is a schematic diagram of the storage mixing tank structure; Figure 4 This is a schematic diagram of the cross-sectional structure of the slag removal chute.

[0015] In the diagram: 1-Storage hopper; 2-Feeder; 3-Digestion and mixing tank; 31-Cooling water jacket; 32-Lifting and mixing mechanism; 33-Temperature sensor; 34-Drain outlet; 35-First water inlet; 36-Flow stabilizer; 37-Slurry outlet; 38-Slag outlet; 4-Slag removal chute; 41-Vibrating screen; 42-Vibrator; 5-Storage and mixing tank; 51-Double-layer anti-sinking mixing paddle; 52-Online concentration monitor; 53-Second water inlet; 54-High-efficiency circulation tank; 6-Transfer pump; 7-Slag hopper; 8-Spiral slag remover. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] like Figures 1-4 As shown, an apparatus for preparing highly active lime slurry from quicklime includes a storage hopper 1, a feeder 2, a digestion and mixing tank 3, a slag removal chute 4, and a storage and mixing tank 5 connected in sequence. The digestion and mixing tank 3 is a circular steel tank with an upper column and a lower cone shape. A cooling water jacket 31 is installed inside the side wall of the tank. The cooling water jacket 31 is connected to a drain port 34 and a first water inlet 35. A lifting and mixing mechanism 32 is installed inside the tank. The lifting and mixing mechanism 32 consists of a porous circulation cylinder and a lifting and mixing paddle. A slurry discharge port 37 is provided at the top of the digestion and mixing tank 3. The bottom of the tank 3 is provided with a slag discharge port 38; the slag removal chute 4 is inclined and connected to the slurry discharge port 37, and the middle of the slag removal chute 4 is provided with a double-layer vibrating screen 41, and a vibrator 42 is provided below the double-layer vibrating screen 41; the storage and mixing tank 5 is a vertical cylindrical steel tank, and the inside of the tank is provided with a high-efficiency circulation tank 54. The bottom of the high-efficiency circulation tank 54 is provided with a double-layer anti-sinking stirring paddle 51. The upper layer of the double-layer anti-sinking stirring paddle 51 is axial flow type, and the lower layer is anchor type. The storage and mixing tank 5 is provided with a second water inlet 53, and the bottom of the storage and mixing tank 5 is also connected to a conveying pump 6.

[0018] The storage hopper 1 has a cube at the top and a square pyramid at the bottom, with a discharge port cone angle ≥60°. The discharge port is equipped with an electro-hydraulic regulating valve. A dust collection hood connected to a bag filter is installed above the storage hopper. The feeder 2 is a variable frequency quantitative closed screw feeder with an adjustable conveying capacity of 150-600 kg / h and an error ≤±1.2%. The digestion mixing tank 3 has a dust collection hood connected to a bag filter at the top and is also equipped with a temperature sensor 33. The bottom slag discharge port 38 of the digestion mixing tank 3 is connected to a spiral slag remover 8 and a slag hopper 7. The slag removal chute 4 is inclined at an angle of 20-25° to the upper slurry discharge port 37 of the digestion mixing tank 3. The double-layer vibrating screen 41 inside the slag removal chute 4 has an upper layer mesh size of 100 mesh and a lower layer mesh size of 200 mesh. An online concentration monitor 52 is installed on the storage mixing tank 5. The feeder 2, digestion mixing tank 3, and storage mixing tank 5 are connected by a PLC.

[0019] Example 1 In this embodiment, the components are configured as follows: The storage hopper 1 is made of wear-resistant steel plate welded together. The upper part is a cube (to facilitate loading by the loader) and the lower part is a square pyramid. The discharge port (cone angle ≥60°) is equipped with an electro-hydraulic regulating valve for storing lumpy quicklime (particle size 20-80mm, CaO content ≥90%). A dust collection hood connected to a bag filter is installed above the storage hopper 1. The discharge port of the storage hopper 1 and the feed port of the feeder 2 are sealed by a flexible connection to prevent dust leakage.

[0020] Feeder 2 adopts a variable frequency quantitative closed screw feeder with adjustable conveying capacity (150-600kg / h, error ≤±1.2%). It is controlled by PLC and linked with the temperature of the subsequent digestion mixing tank 3 to ensure that quicklime enters the digestion mixing tank 3 at a uniform speed and avoid excessive feeding, which would lead to violent reaction and excessive heat.

[0021] The main body of the digestion mixing tank 3 is a circular steel tank with an upper column and a lower cone (length-to-diameter ratio 2:1). It is equipped with a cooling water jacket 31 and circulates cooling water (inlet water temperature 25-30℃). An internal lifting and stirring mechanism 32 is installed (the lifting and stirring mechanism 32 consists of a porous circulation cylinder and a lifting and stirring paddle, with a rotation speed of 120-180 r / min). This enhances the mixing and contact between quicklime and water, stabilizes the temperature of the slurry in the digestion mixing tank 3, and allows coarse and fine particles of insoluble matter to naturally stratify according to their respective circulation trajectories. A temperature sensor 33 (measuring range 50-150℃) is installed inside the digestion mixing tank 3. The reaction temperature is fed back in real time, and the cooling water jacket 31 is linked to adjust the cooling water flow rate to control the reaction temperature at 85-95℃ (optimal 90℃), ensuring that CaO is quickly converted into Ca(OH)2 with fine crystals (average particle size ≤20μm); the top of the digestion mixing tank 3 is equipped with a dust suction hood (connected to a bag filter) and a first water inlet 35 (used to adjust the water-cement ratio, water:quicklime = 1.8-2.2:1); the upper part of the digestion mixing tank 3 is equipped with a slurry discharge port 37, which is connected to the slag removal chute 4; the bottom of the digestion mixing tank 3 is equipped with a slag discharge port 37, which is connected to the spiral slag remover 8 to discharge the slag into the slag hopper 7.

[0022] The slag removal chute 4 is connected to the upper part of the digestion mixing tank 3 by a discharge port 37, with an inclination angle of 20-25°. The tank body is made of stainless steel (5mm thick), and the length to width ratio is 8:1 to ensure low-speed flow of the slurry (flow velocity 0.08-0.2m / s). A double-layer vibrating screen 41 is installed in the middle of the tank (the upper layer has a mesh size of 100 to intercept undigested CaO, and the lower layer has a mesh size of 200 to intercept silicon and aluminum impurity particles). The screen material is polyurethane (wear-resistant). A spiral slag remover 8 (motor power 0.75kW, speed 15r / min) is installed below the double-layer vibrating screen 41 to continuously push the intercepted impurities to the slag hopper 7 for discharge. The bottom outlet of the slag removal chute 4 is connected to the downstream storage mixing tank 5, and the feed and water supply of the digestion mixing tank 3 are automatically adjusted according to the liquid level signal of the storage mixing tank 5.

[0023] The storage and mixing tank 5 is a vertical cylindrical steel tank (effective volume is 2.5 to 3 times that of the digestion tank); it is equipped with a double-layer anti-settling mixing paddle 51: the upper layer is axial flow type (rotation speed 30-50 r / min, pushing the slurry upward), and the lower layer is anchor type (rotation speed 15-25 r / min, preventing bottom sedimentation), forming an upper and lower circulating flow field to prevent Ca(OH)2 particles from settling; the storage and mixing tank 5 is equipped with an online concentration monitoring meter 52 to provide real-time feedback on the slurry concentration; when the concentration is lower than the target value (1.15 g / cm³), it is automatically replenished with water through the upper second water inlet 53; a discharge port is provided at the bottom and connected to the inlet of the conveying pump 6.

[0024] The transfer pump 6 is a fluoroplastic centrifugal pump (material F46) with double-end mechanical seals. The flow rate is adjustable (8-25m³ / h), the head is 30-50m, and it has strong corrosion resistance. It can stably transport lime slurry to the flotation process.

[0025] The working process of this embodiment is as follows: Quicklime feeding and quantitative feeding: Lump quicklime (20-80mm, CaO≥80%) is added to the storage hopper 1 by a loader and then uniformly conveyed to the digestion mixing tank 3 at a rate of 300kg / h by a variable frequency quantitative screw feeder 2.

[0026] Temperature-controlled digestion reaction: 25℃ circulating cooling water is introduced into the cooling water jacket 31 of the digestion stirring tank 3 to maintain the reaction temperature in the tank at 90℃; the lifting stirring mechanism 32 (porous circulating cylinder and lifting stirring paddle, speed 120-180r / min) vigorously stirs the quicklime and water (water-lime ratio 2:1) to fully contact each other and quickly complete the digestion reaction (CaO→Ca(OH)2); the temperature sensor 33 monitors in real time, and if the temperature exceeds 95℃, the cooling water flow rate is increased to cool down; coarse slag and large insoluble particles are discharged from the slag discharge port 38 at the bottom of the cone into the slag hopper 7 for external discharge at regular intervals.

[0027] Impurity separation and slag removal: The digested slurry enters the slag removal chute 4 from the upper slurry outlet 37 of the digestion mixing tank 3 and flows at a low speed of 0.2m / s; the double-layer vibrating screen 41 intercepts undigested CaO particles (>75μm) and silicon-aluminum impurities, and the impurities are pushed to the slag hopper 7 by the spiral slag remover 8 for discharge; after slag removal, the slurry enters the storage mixing tank 5.

[0028] Anti-sedimentation storage and transportation: After the slurry enters the storage and mixing tank 5, the double-layer anti-sedimentation stirring paddle 51 (upper layer axial flow type 50r / min, lower layer anchor type 25r / min) continuously stirs to form a circulating flow field to prevent Ca(OH)2 from settling; the online concentration monitor 52 monitors the concentration in real time (target 15%). If the concentration is too high (e.g., 13%), the PLC controls the automatic triggering of the top second water inlet 53 to add water; after reaching the standard, it is transported to the flotation process by the delivery pump 6 (flow rate 15m³ / h) to adjust the slurry potential to the optimal range of -200 to -250mV.

Claims

1. An apparatus for preparing highly active lime slurry using quicklime, characterized in that: The digestion and mixing tank includes a storage hopper (1), a feeder (2), a digestion and mixing tank (3), a slag removal chute (4), and a storage and mixing tank (5) connected in sequence. The main body of the digestion and mixing tank (3) is a circular steel tank with an upper column and a lower cone. A cooling water jacket (31) is provided inside the side wall of the tank. The cooling water jacket (31) is connected to a drain port (34) and a first water inlet (35). A lifting and mixing mechanism (32) is provided inside the tank. The lifting and mixing mechanism (32) consists of a perforated circulation cylinder and a lifting and mixing paddle. A slurry discharge port (37) is provided at the top of the digestion and mixing tank (3), and a slag discharge port (37) is provided at the bottom of the digestion and mixing tank (3). 38); The slag removal chute (4) is inclined and connected to the slurry discharge port (37). The middle part of the slag removal chute (4) is equipped with a double-layer vibrating screen (41), and a vibrator (42) is provided below the double-layer vibrating screen (41); The storage and mixing tank (5) is a vertical cylindrical steel tank. The tank is equipped with a high-efficiency circulation tank (54). The bottom of the high-efficiency circulation tank (54) is equipped with a double-layer anti-sinking stirring paddle (51). The upper layer of the double-layer anti-sinking stirring paddle (51) is axial flow type, and the lower layer is anchor type. The storage and mixing tank (5) is equipped with a second water inlet (53). The bottom of the storage and mixing tank (5) is also connected to a conveying pump (6).

2. The apparatus for preparing highly active lime slurry using quicklime according to claim 1, characterized in that: The upper part of the storage hopper (1) is a cube, the lower part is a square pyramid, the cone angle of the discharge port is ≥60°, the discharge port is equipped with an electro-hydraulic regulating valve, and the storage hopper (1) is equipped with a dust collection hood connected to a bag filter.

3. The apparatus for preparing highly active lime slurry from quicklime according to claim 1 or 2, characterized in that: The feeder (2) is a variable frequency quantitative closed screw feeder with an adjustable conveying capacity of 150-600 kg / h and an error of ≤±1.2%.

4. The apparatus for preparing highly active lime slurry from quicklime according to claim 3, characterized in that: The digestion mixing tank (3) is equipped with a dust collection hood connected to a bag filter at the top. The digestion mixing tank (3) is also equipped with a temperature sensor (33). The bottom slag discharge port (38) of the digestion mixing tank (3) is connected to a spiral slag remover (8) and a slag hopper (7).

5. The apparatus for preparing highly active lime slurry from quicklime according to claim 4, characterized in that: The slag removal chute (4) and the slurry discharge port (37) at the top of the digestion stirring tank (3) are inclined at an angle of 20-25°. The upper layer of the double-layer vibrating screen (41) in the slag removal chute (4) has a mesh size of 100 mesh and the lower layer has a mesh size of 200 mesh.

6. The apparatus for preparing highly active lime slurry from quicklime according to claim 5, characterized in that: The storage and stirring tank (5) is equipped with an online concentration monitoring meter (52).

7. The apparatus for preparing highly active lime slurry from quicklime according to claim 6, characterized in that: The feeder (2), digestion mixing tank (3) and storage mixing tank (5) are connected by a PLC.

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