Sectional washing system for aluminum hydroxide

Abstract

The utility model belongs to the technical field of aluminum hydroxide washing, and particularly relates to an aluminum hydroxide sectional washing system which comprises n washing areas, a tank A and a tank B. Each washing area comprises x washing sections, the washing water inlet of the xth washing section is connected with external clean washing water through a first pipeline, and the filtrate outlet of the xth washing section is connected with the washing water inlet of the previous washing section through a second pipeline; a filtrate outlet of the first washing section is connected with the tank A through a third pipeline to be used as washing water for a sedimentation process or is connected with the tank B through a fourth pipeline to be used as washing liquid for fourth washing or fifth washing of a red mud washing process; n > = 2, and x > = 1. According to the system disclosed by the utility model, the washing mode of aluminum hydroxide can be changed, the aluminum hydroxide can be washed in sections, the washing water consumption is reduced, the filtrate treatment mode of each section is changed, and the evaporation steam consumption is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of aluminum hydroxide washing, and particularly relates to a segmented washing system for aluminum hydroxide. Background Art

[0002] Aluminum oxide is a stable oxide of aluminum, with the chemical formula Al 2 O 3 . It is also known as bauxite in the mining industry, ceramics industry and materials science. Aluminum oxide has a wide range of uses and can be used as an analytical reagent, dehydration agent for organic solvents, adsorbent, organic reaction catalyst, abrasive, polishing agent, raw material for smelting aluminum, and refractory material. In the prior art, usually, ore is first prepared into aluminum hydroxide, and then the aluminum hydroxide is washed with hot water and then calcined to obtain aluminum oxide, and then it is packaged and sold. A large amount of washing filtrate is generated during the hot water washing process of aluminum hydroxide, and these washing filtrates are sent to the evaporation area for evaporation treatment. Insufficient washing water will lead to incomplete washing, resulting in unqualified purity of aluminum oxide. If the washing water consumption is too large, it will greatly increase the evaporation energy consumption and increase the production cost of aluminum oxide. Content of the Utility Model

[0003] In view of the problems existing in the prior art, the utility model provides a segmented washing system for aluminum hydroxide, and the specific content of the utility model includes the following:

[0004] A segmented washing system for aluminum hydroxide, including n washing areas, tank A and tank B. Each washing area includes x washing segments. The wash water inlet of the x-th washing segment is connected to the external clean wash water through a first pipeline, and the filtrate outlet of the x-th washing segment is connected to the wash water inlet of the previous washing segment through a second pipeline. The filtrate outlet of the first washing segment in the 1st to (n - y)th washing areas is connected to tank A through a third pipeline and sent for evaporation, while the filtrate outlet of the first washing segment in the nth to (n - y + 1)th washing areas is connected to tank B through a fourth pipeline and sent for sedimentation as the washing liquid for the fourth or fifth washing in the red mud washing process. A first valve and a first water pump are arranged on the first pipeline; a second valve and a second water pump are arranged on the second pipeline; a third valve and a third water pump are arranged on the third pipeline; a fourth valve and a fourth water pump are arranged on the fourth pipeline; n≥2, x≥1, y≥0.

[0005] Preferably, the n washing areas are arranged on a flat plate filter or a belt filter.

[0006] Preferably, a spraying device is arranged above the flat plate filter or the belt filter in each washing segment, and a filtrate outlet is arranged at the bottom. The spraying device is provided with a wash water inlet and a plurality of spraying nozzles.

[0007] Preferably, an automatic control device is further included, and the automatic control device is respectively connected to the first water pump, the second water pump, the third water pump, the fourth water pump, the first valve, the second valve, the third valve, and the fourth valve. When needed, the working states of the first water pump, the second water pump, the third water pump, the fourth water pump, the first valve, the second valve, the third valve, and the fourth valve can be controlled through the automatic control device to realize the fully automatic operation of the entire device.

[0008] Preferably, the total alkali Nt (calculated as Na 2 O) concentration in the B tank should be controlled according to the washing concentration gradient, and preferably the Nt concentration ≤ 20 g / L. In addition, the suspended matter control in the B tank should be as low as possible, preferably below 1 g / L.

[0009] Advantages of the present utility model:

[0010] Using the system disclosed by the utility model, the segmented washing of aluminum hydroxide can be realized. The aluminum hydroxide passes through n washing zones, and each washing zone includes x washing segments. In each washing zone, the xth washing segment is washed with clean wash water, and the next washing segment uses the filtrate generated by the previous washing segment as the wash water. The filtrate generated by the first washing segment is collected into the A tank to be used as the wash water for the sedimentation process or collected into the B tank and sent to the evaporation process. It should be noted that whether the filtrate generated by the first washing segment is specifically sent to the A tank or the B tank can be selected according to the specific composition and concentration of the filtrate and the specific requirements of the product. Among them, the specific settings of the washing zones and the washing segments in each washing zone can be adjusted according to the actual product requirements. Generally speaking, the number of washing zones is not less than 2, and the number of washing segments is not less than one. In addition, usually the total alkali (calculated as Na 2 O) concentration control in the B tank should be controlled according to the washing concentration gradient, and preferably the total alkali (calculated as Na 2 O) concentration ≤ 20 g / L, and the suspended matter control in the B tank should be as low as possible, preferably below 1 g / L. The system disclosed by the present utility model can change the washing method of aluminum hydroxide, perform segmented washing on aluminum hydroxide, reduce the consumption of wash water, and at the same time change the treatment method of each segment of filtrate to reduce the evaporation steam consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic structural diagram of the system disclosed by the present utility model;

[0012] Figure 2 is a schematic process flow diagram of the segmented washing of aluminum hydroxide disclosed by the embodiment of the present utility model;

[0013] Figure 3 is a schematic process flow diagram of the segmented washing of aluminum hydroxide disclosed by the embodiment of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0014] The present utility model will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments shown below do not impose any limitation on the content of the utility model recited in the claims. In addition, all the contents of the configurations shown in the following embodiments are not limited to those necessary for the solution of the utility model recited in the claims.

[0015] Referring to Figure 1 , where the arrows in the figure indicate the material flow direction, an aluminum hydroxide segmented washing system includes n washing zones, a tank A and a tank B. Each of the washing zones includes x washing segments. The wash water inlet of the x-th washing segment is connected to the external clean wash water through a first pipeline, and the filtrate outlet of the x-th washing segment is connected to the wash water inlet of the previous washing segment through a second pipeline. The filtrate outlet of the first washing segment is connected to the tank A through a third pipeline for use as the wash water in the sedimentation process or is connected to the tank B through a fourth pipeline and sent to the sedimentation as the wash liquid for the fourth or fifth washing in the red mud washing process; a first valve and a first water pump are provided on the first pipeline; a second valve and a second water pump are provided on the second pipeline; a third valve and a third water pump are provided on the third pipeline; a fourth valve and a fourth water pump are provided on the fourth pipeline; n≥2 and x≥1.

[0016] In an embodiment of the present utility model, the n washing zones are arranged on a pan filter or a belt filter.

[0017] In an embodiment of the present utility model, a spraying device is arranged above the pan filter or the belt filter of each washing segment, and a filtrate outlet is arranged at the bottom. The spraying device is provided with a wash water inlet and a plurality of spraying nozzles.

[0018] In an embodiment of the present utility model, an automatic control device is further included. The automatic control device is respectively connected to the first water pump, the second water pump, the third water pump, the fourth water pump, the first valve, the second valve, the third valve and the fourth valve. When needed, the working states of the first water pump, the second water pump, the third water pump, the fourth water pump, the first valve, the second valve, the third valve and the fourth valve can be controlled through the automatic control device to realize the fully automatic operation of the whole device.

[0019] Referring to Figure 2, using the system disclosed by the utility model, staged washing of aluminum hydroxide can be achieved. The aluminum hydroxide passes through n washing zones, and each washing zone includes x washing stages. In each washing zone, the x-th washing stage is washed with clean wash water, and the next washing stage uses the filtrate generated by the previous washing stage as wash water. The filtrate generated by the first washing stage is collected in tank A and used as wash water for the sedimentation process, or collected in tank B and sent to sedimentation as the washing liquid for the fourth or fifth washing in the red mud washing process. It should be noted that whether the filtrate generated by the first washing stage specifically leads to tank A or tank B can be selected according to the specific composition and concentration of the filtrate and the specific requirements of the product. Among them, the specific settings of the washing zones and the washing stages in each washing zone can be adjusted according to the actual product requirements. Generally speaking, there are at least 2 washing zones and at least one washing stage. In addition, usually, the total alkali (calculated as Na 2 O) concentration control in tank B should be controlled according to the washing concentration gradient. Preferably, the total alkali (calculated as Na 2 O) concentration ≤ 20 g / L, and the control of suspended matter in tank B should be as low as possible, preferably below 1 g / L. The washed aluminum hydroxide is sent to a drying device for drying to obtain aluminum hydroxide products. The system disclosed by the utility model can change the washing method of aluminum hydroxide, perform staged washing of aluminum hydroxide, reduce the consumption of wash water, and at the same time change the treatment method of the filtrate in each stage, reducing the evaporation steam consumption.

[0020] Example 1

[0021] Reference Figure 3 , taking the production of aluminum hydroxide products by a flat pan as an example, because the application direction of this aluminum hydroxide product has relatively high requirements for the alkali content and conductivity indicators, the single consumption of wash water reaches 0.6 - 1 t / t, and the washed filtrate is all sent to the evaporation area.

[0022] The staged washing is carried out using the aluminum hydroxide staged washing system disclosed by the utility model. The 1# washing zone is provided with 2 washes. The first wash uses 0.3 t / t - AH of clean wash water. The filtrate after washing is used as the wash water for the 2nd wash in this zone, and the filtrate after washing is sent to evaporation. The 2# washing zone is provided with 1 wash, and 0.3 t / t - AH of clean wash water is used to wash the aluminum hydroxide to obtain qualified aluminum hydroxide products. The filtrate Nt concentration is 1.5 - 4 g / L, and it is returned to the wash water tank of the washing system as the wash water for the fifth wash. The evaporation and water evaporation amount per ton of aluminum hydroxide products can be reduced by 0.3 - 0.7 t.

[0023] Example 2

[0024] A segmented washing system for aluminum hydroxide, comprising three washing zones arranged on a horizontal disk filter, a tank A and a tank B. Each washing zone includes three washing segments. Above the horizontal disk filter of each washing segment, a spraying device is arranged, and a filtrate outlet is arranged at the bottom. The spraying device is provided with a washing water inlet and a plurality of spraying nozzles. The washing water inlet of the third washing segment is connected to the externally connected clean washing water through a first pipeline, and the filtrate outlet of the third washing segment is connected to the washing water inlet of the previous washing segment through a second pipeline. The filtrate outlet of the first washing segment is connected to the tank A through a third pipeline for use as washing water in the sedimentation process or is connected to the tank B through a fourth pipeline and sent to sedimentation as the washing liquid for the fourth or fifth washing in the red mud washing process. A first valve and a first water pump are arranged on the first pipeline; a second valve and a second water pump are arranged on the second pipeline; a third valve and a third water pump are arranged on the third pipeline; a fourth valve and a fourth water pump are arranged on the fourth pipeline.

[0025] When using the system disclosed in this embodiment to perform segmented washing of aluminum hydroxide, the aluminum hydroxide passes through three washing zones, and each washing zone includes three washing segments. In each washing zone, the third washing segment is washed with clean washing water, and the next washing segment uses the filtrate generated by the previous washing segment as washing water. The filtrate generated by the first washing segment of the first washing zone is collected into the tank B and sent to the evaporation process, and the filtrates generated by the first washing segments of the second and third washing zones are collected into the tank A and used as washing water in the sedimentation process. Through experimental verification, when using the disclosed segmented washing system for aluminum hydroxide to wash aluminum hydroxide, compared with the traditional washing method, the impurity content of the aluminum hydroxide product is lower, and the evaporation water volume per ton of aluminum hydroxide product can be reduced by 0.4 - 0.5 t.

[0026] Embodiment 3

[0027] A segmented washing system for aluminum hydroxide, comprising two washing zones arranged on a horizontal disk filter, a tank A and a tank B. Each washing zone includes four washing segments. Above the horizontal disk filter of each washing segment, a spraying device is arranged, and a filtrate outlet is arranged at the bottom. The spraying device is provided with a washing water inlet and a plurality of spraying nozzles. The washing water inlet of the fourth washing segment is connected to the externally connected clean washing water through a first pipeline, and the filtrate outlet of the fourth washing segment is connected to the washing water inlet of the previous washing segment through a second pipeline. The filtrate outlet of the first washing segment is connected to the tank A through a third pipeline for use as washing water in the sedimentation process or is connected to the tank B through a fourth pipeline and sent to sedimentation as the washing liquid for the fourth or fifth washing in the red mud washing process. A first valve and a first water pump are arranged on the first pipeline; a second valve and a second water pump are arranged on the second pipeline; a third valve and a third water pump are arranged on the third pipeline; a fourth valve and a fourth water pump are arranged on the fourth pipeline.

[0028] Using the system disclosed in this embodiment for the staged washing of aluminum hydroxide, the aluminum hydroxide passes through 2 washing zones, and each washing zone includes 4 washing stages. In each washing zone, the 4th washing stage is washed with clean wash water, and the next washing stage uses the filtrate generated by the previous washing stage as the wash water. The filtrate generated by the 1st washing stage of the 1st - 2nd washing zones is collected into tank B and sent to the evaporation process, and the filtrate generated by the 1st washing stage of the 3rd - 4th washing zones is collected into tank A and used as the wash water for the sedimentation process. Through experimental verification, when using the staged aluminum hydroxide washing system disclosed in this embodiment for aluminum hydroxide washing, compared with the traditional washing method, the impurity content of the aluminum hydroxide product is lower, and the evaporation water volume can be reduced by 0.6 - 0.8 t per ton of aluminum hydroxide product.

[0029] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An aluminum hydroxide staged washing system, characterized in that: The invention comprises n washing areas, a tank A and a tank B, each of the washing areas comprises x washing sections, the washing water inlet of the x-th washing section is connected to the external clean washing water through a first pipe, the filtrate outlet of the x-th washing section is connected to the washing water inlet of the previous washing section through a second pipe, the filtrate outlet of the first washing section is connected to the tank A through a third pipe or to the tank B through a fourth pipe; a first valve and a first water pump are arranged on the first pipe; a second valve and a second water pump are arranged on the second pipe; a third valve and a third water pump are arranged on the third pipe; a fourth valve and a fourth water pump are arranged on the fourth pipe; and n≥2, x≥1.

2. An aluminum hydroxide staged washing system according to claim 1, characterized in that: The n washing zones are arranged on a flat disc filter or a belt filter.

3. An aluminum hydroxide staged washing system according to claim 2, characterized in that: A spray device is arranged above the flat plate filter or the belt filter of each washing section, and a filtrate outlet is arranged at the bottom. The spray device is provided with a washing water inlet and a plurality of spray outlets.

4. A staged aluminum hydroxide washing system according to claim 2, characterized in that: It also includes an automatic control device, which is connected to the first water pump, the second water pump, the third water pump, the fourth water pump, the first valve, the second valve, the third valve and the fourth valve respectively.

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