Efficient impurity removal device for dissolved slurry

Abstract

An efficient impurity removal device for dissolved slurry comprises a settling tank, a crude liquid tank and a leaf filter, a feeding port of the settling tank is used for being connected with a dissolved slurry source, an overflow pipe is arranged on the upper portion of the side wall of the settling tank to supply materials to the crude liquid tank, a discharging port of the crude liquid tank supplies materials to the leaf filter through a conveying pump, and a feeding mechanism is arranged on the overflow pipe. The feeding mechanism comprises a liquid inlet pipe which is bent and extends in a snake shape, the upstream end of the liquid inlet pipe is connected with the liquid preparation tank, the downstream end of the liquid inlet pipe is communicated with the overflow pipe, and the liquid preparation tank is provided with a first inlet used for being connected with a lime milk source and a second inlet used for being connected with a filter aid source. The device is simple in structure and low in improvement cost, and can reduce the use amount of lime milk on the basis of ensuring that impurities in the dissolved slurry are removed.

Description

Technical Field

[0001] The utility model relates to the field of aluminum oxide production, in particular to a high-efficiency impurity removal device for dissolved slurry. Background Art

[0002] Alumina production enterprises use bauxite as raw material, and obtain dissolution slurry through grinding and low-temperature dissolution. The red mud produced by low-temperature dissolution is washed to obtain red mud washing liquid which needs to be mixed with the dissolution slurry to obtain dissolution dilution slurry. The dissolution dilution slurry contains insoluble solids, small suspended particles (red mud), and the target sodium aluminate. After the dissolution dilution slurry passes through the sedimentation tank to separate the insoluble solids and the coarse liquid tank to separate the small suspended particles, it passes through the leaf filter to obtain the fine liquid for use in the downstream process.

[0003] At present, calcium hydroxide solution is usually added directly to the coarse liquid tank to remove small suspended particles. However, adding calcium hydroxide solution directly to the coarse liquid tank results in low utilization rate of calcium hydroxide, large consumption of calcium hydroxide, and poor encapsulation effect on small suspended particles due to poor crystal form generated, and some small suspended particles adhere to the leaf filter membrane, resulting in a short maintenance cycle of the leaf filter. In addition, some small suspended particles also pass through the leaf filter membrane into the semen, causing the suspended liquid content in the semen to exceed the standard, which is not conducive to controlling product quality.

[0004] Therefore, how to design a device that can efficiently remove impurities in the dissolution slurry is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] The utility model aims to provide a high-efficiency impurity removal device for dissolving slurry in view of the deficiencies of the prior art, which has a simple structure and low transformation cost, and can reduce the amount of lime milk used while ensuring the removal of impurities in the dissolving slurry.

[0006] The technical scheme of the utility model is: a high-efficiency impurity removal device for leached slurry, comprising a sedimentation tank, a coarse liquid tank, and a leaf filter, wherein the feed port of the sedimentation tank is used to be connected to a source of leached slurry, an overflow pipe is arranged on the upper part of the side wall of the sedimentation tank to feed the coarse liquid tank, and the discharge port of the coarse liquid tank feeds the leaf filter through a feed pump, a feeding mechanism is arranged on the overflow pipe, and the feeding mechanism comprises a liquid inlet pipe extending in a serpentine shape, the upstream end of the liquid inlet pipe is connected to a liquid distribution tank, and the downstream end of the liquid inlet pipe is connected to the overflow pipe, the liquid distribution tank is provided with a first inlet for being connected to a source of lime milk, and a second inlet is arranged for being connected to a source of filter aid.

[0007] The coarse liquid tank is provided with a lime milk feeding pipe.

[0008] The discharge port of the rough liquid tank is arranged at the bottom of the side wall of the rough liquid tank.

[0009] The overflow pipe is provided with a first flow meter and a first control valve, and the upstream end of the liquid inlet pipe is provided with a second flow meter and a second control valve.

[0010] The coarse liquid tank is provided with a stirrer.

[0011] The filter aid is diatomaceous earth.

[0012] The amount of filter aid added to the lime milk is 0.4-1.5 parts per ten thousand, the concentration of lime milk is 120-150g / L, and the amount of filter aid added to the crude liquid is 5-10 parts per million.

[0013] The above technical solution has the following beneficial effects:

[0014] 1. The efficient impurity removal device for the leached slurry includes a sedimentation tank, a coarse liquid tank, and a leaf filter. The feed port of the sedimentation tank is used to be connected to the leached slurry source. An overflow pipe is arranged on the upper part of the side wall of the sedimentation tank to feed the coarse liquid tank. The discharge port of the coarse liquid tank feeds the leaf filter through a feed pump. The sedimentation tank is used to sediment and separate the coarse liquid and red mud in the leached slurry. The coarse liquid tank is used to temporarily retain the coarse liquid and form hydrated calcium aluminate crystals to absorb small suspended particles in the coarse liquid. The leaf filter is used to separate impurities in the coarse liquid and discharge the slurry concentrate to the outside. The overflow pipe is provided with a feeding mechanism, which includes a liquid inlet pipe extending in a serpentine shape, the upstream end of the liquid inlet pipe is connected to the liquid distribution tank, the downstream end of the liquid inlet pipe is connected to the overflow pipe, the liquid distribution tank is provided with a first inlet for connecting to a lime milk source, and a second inlet for connecting to a filter aid source, the lime milk is first mixed with the filter aid in the liquid distribution tank, and then mixed with the crude liquid in the overflow pipe through the liquid inlet pipe extending in a serpentine shape, the flow direction of the lime milk containing the filter aid changes back and forth during the flow process, and the filter aid can be evenly dispersed in the liquid distribution tank without using a stirrer. In the lime milk, the continuous addition of lime milk to the overflow liquid is realized to meet the needs of continuous production of the enterprise. In addition, the lime milk containing filter aids is first mixed with the crude liquid in the overflow pipe, which also ensures the mixing effect and efficiency of the lime milk and the crude liquid. Even the stirring device in the crude liquid tank can be eliminated, and the energy consumption is reduced. The lime milk in the crude liquid tank reacts with part of the sodium aluminate to generate hydrated calcium aluminate crystals, and under the action of the filter aid, the crystal particle size of the model layer is coarser and the particle size distribution is narrower, which has a better adsorption effect on small particle suspended matter, and the use of lime milk can be reduced to meet the goal of impurity removal. The filter cake formed by the generated hydrated calcium aluminate crystals on the surface of the leaf filter cloth has the characteristics of "porous, better crystal form, and larger particle size", has a good filtering effect on impurities in the crude liquid, and also improves the quality of the discharged slurry semen.

[0015] 2. A lime milk feed pipe is provided on the coarse liquid tank, which can be used to add lime milk to the coarse liquid tank as needed to meet the actual needs of the enterprise.

[0016] 3. The overflow pipe is provided with a first flow meter and a first control valve, and the upstream end of the liquid inlet pipe is provided with a second flow meter and a second control valve. The first flow meter and the second flow meter cooperate with the first control valve and the second control valve to achieve accurate batching of lime milk and crude liquid, thereby avoiding waste of lime milk while ensuring the impurity removal effect.

[0017] The applicant has verified that the use of the impurity removal device of the utility model can reduce the amount of lime used by more than 10%, saving 400t of lime per month.

[0018] Further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the utility model.

[0020] In the accompanying drawings, 1 is a sedimentation tank, 2 is a coarse liquid tank, 3 is a leaf filter, 4 is an overflow pipe, 5 is a feed pump, 6 is a feeding mechanism, 7 is a liquid inlet pipe, 8 is a liquid distribution tank, 9 is a first inlet, 10 is a second inlet, 11 is a lime milk feed pipe, 12 is a first flow meter, 13 is a first control valve, 14 is a second flow meter, 15 is a second control valve, and 16 is an agitator. DETAILED DESCRIPTION

[0021] In the utility model, the filter aid used is diatomaceous earth, which is purchased from Henan Sanmenxia Zilai New Materials Co., Ltd.

[0022] See also Figure 1 , which is a specific embodiment of a high-efficiency impurity removal device for dissolution slurry. The high-efficiency impurity removal device for dissolution slurry comprises a sedimentation tank 1, a coarse liquid tank 2, and a leaf filter 3. The feed port of the sedimentation tank 1 is used to be connected to the source of dissolution slurry, and an overflow pipe 4 is arranged on the upper part of the side wall of the sedimentation tank 1 to feed the coarse liquid tank 2. Usually, an agitator 16 is also required to be arranged in the coarse liquid tank 2, and a lime milk feed pipe 11 is arranged as a backup. The discharge port of the coarse liquid tank 2 feeds the leaf filter 3 through a feed pump 5. Specifically, the discharge port of the coarse liquid tank is arranged at the bottom of the side wall of the coarse liquid tank. The overflow pipe 4 is provided with a feeding mechanism 6, and the feeding mechanism 6 includes a liquid inlet pipe 7 extending in a serpentine shape, the upstream end of the liquid inlet pipe 7 is connected to the liquid distribution tank 8, and the downstream end of the liquid inlet pipe 7 is connected to the overflow pipe 4. In order to facilitate the measurement and control of the flow rate, the overflow pipe 4 is provided with a first flow meter 12 and a first control valve 13, and the upstream end of the liquid inlet pipe 7 is provided with a second flow meter 14 and a second control valve 15. The liquid distribution tank 8 is provided with a first inlet 9 for connecting to a lime milk source, and a second inlet 10 for connecting to a filter aid source.

[0023] The working principle of the utility model is:

[0024] The dissolved slurry enters the sedimentation tank for sedimentation separation, wherein the red mud at the bottom is washed and used for other purposes, and the crude liquid at the top overflows into the crude liquid tank through the overflow pipe. At the same time, lime milk and filter aids are added to the liquid preparation tank, wherein the concentration of lime milk is 120-150g / L, and the amount of filter aid added to the lime milk is 0.4-1.5 parts per ten thousand, that is, the content of filter aid in the lime milk is 40-150ppm. The opening of the second control valve is controlled so that the lime milk containing filter aid is fully mixed through the liquid inlet pipe, and then added to the overflow pipe and mixed with the flowing crude liquid. By controlling the opening of the first control valve and the second control valve, the content of filter aid in the crude liquid is finally made 5-10ppm. Hydrated calcium aluminate crystals with coarse particle size and narrow particle size distribution are formed in the coarse liquid entering the coarse liquid tank, which adsorb small suspended particles. The coarse liquid in the coarse liquid tank is then sent to the leaf filter for separation. At the same time, the hydrated calcium aluminate crystals form a porous filter cake with good crystal shape and large grains on the filter cloth of the leaf filter, which serves as a filtration layer to improve the quality of the slurry semen discharged from the leaf filter.

Claims

1. A highly efficient impurity removal device for a dissolution slurry, comprising a sedimentation tank (1), a coarse liquid tank (2), and a leaf filter (3), wherein the feed port of the sedimentation tank (1) is used to be connected to a source of the dissolution slurry, an overflow pipe (4) is provided on the upper part of the side wall of the sedimentation tank (1) to feed the coarse liquid tank (2), and the discharge port of the coarse liquid tank (2) feeds the leaf filter (3) through a feed pump (5), characterized in that: The overflow pipe (4) is provided with a feeding mechanism (6), the feeding mechanism (6) comprising a liquid inlet pipe (7) extending in a serpentine shape, the upstream end of the liquid inlet pipe (7) being connected to a liquid distribution tank (8), the downstream end of the liquid inlet pipe (7) being connected to the overflow pipe (4), the liquid distribution tank (8) being provided with a first inlet (9) for connecting to a lime milk source, and a second inlet (10) for connecting to a filter aid source.

2. The high-efficiency impurity removal device for dissolution slurry according to claim 1, characterized in that: The coarse liquid tank (2) is provided with a lime milk feeding pipe (11).

3. The high-efficiency impurity removal device for dissolution slurry according to claim 1 is characterized in that: The discharge port of the rough liquid tank is arranged at the bottom of the side wall of the rough liquid tank.

4. The high-efficiency impurity removal device for dissolution slurry according to claim 1, characterized in that: The overflow pipe (4) is provided with a first flow meter (12) and a first control valve (13), and the upstream end of the liquid inlet pipe (7) is provided with a second flow meter (14) and a second control valve (15).

5. The high-efficiency impurity removal device for dissolution slurry according to claim 1, characterized in that: The coarse liquid tank (2) is provided with a stirrer (16).

6. The high-efficiency impurity removal device for dissolution slurry according to claim 1, characterized in that: The filter aid is diatomaceous earth.

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