A method of reducing the moisture content of disc filter concentrate

Abstract

This invention discloses a method for reducing the moisture content of concentrate powder produced by disc filters. It is based on a dual-vacuum partitioning modification of a disc vacuum filter, dividing the dewatering zone of the filter into independently controlled adsorption and dewatering zones. Specifically, the method includes the following steps: A) Feeding and distributing: The concentrate slurry to be dewatered is uniformly fed onto the surface of the filter discs; B) Process partitioning: Along the rotation direction of the filter discs, the filtration working area is sequentially divided into an adsorption zone and a dewatering zone. This invention, by independently controlling the adsorption and dewatering zones of the disc vacuum filter, breaks through the limitations of traditional single vacuum levels. The moisture content of the concentrate powder is reduced by 3-5 percentage points compared to traditional single vacuum processes. Furthermore, the adsorption zone uses high negative pressure for rapid cake formation, shortening the cake formation time by more than 30%. This means that at the same disc filter speed, the effective dewatering time percentage increases, or the speed can be appropriately increased to achieve the same production capacity, thus improving the overall processing capacity.

Description

Technical Field

[0001] This invention relates to the field of mineral processing and solid-liquid separation technology, specifically a method for reducing the moisture content of concentrate powder produced by disc filtration. Background Technology

[0002] Disc vacuum filters are core equipment for dewatering concentrates of metal and non-metal minerals. Their dewatering effect directly determines the moisture content of concentrate powder, transportation costs, and subsequent processing efficiency. Traditional disc vacuum filters adopt a single vacuum degree full-range control mode. In the early stage of cake formation, the material concentration is low and the fluidity is good, requiring a high vacuum degree to quickly adsorb solid particles and form an initial filter cake. However, the single vacuum degree is often set too low to take into account overall dewatering, resulting in slow cake formation speed, thin and uneven initial cake layer, which affects the subsequent dewatering efficiency. Moreover, there is no air resistance protection during the dewatering stage, resulting in serious air back penetration, large ineffective air volume in the vacuum system, high energy consumption, and low dewatering efficiency. At the same time, the filter cake formation cycle is long, dewatering is incomplete, and the moisture content of concentrate powder remains high, which cannot meet the requirements for low-moisture concentrate production. Therefore, we propose a method to reduce the moisture content of concentrate powder produced by disc filters. Summary of the Invention

[0003] The purpose of this invention is to provide a method for reducing the moisture content of concentrate powder produced by disc filtration, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for reducing the moisture content of concentrate powder produced by disc filtration, based on a dual-vacuum partition modification of a disc vacuum filter, which divides the dehydration zone of the filter into an independently controlled adsorption zone and a dehydration zone, specifically including the following steps: A. Feeding and spreading: The concentrate slurry to be dewatered is evenly fed to the surface of the filter disc; B. Process Zoning: Along the rotation direction of the filter disc, the filtration working area is divided into an adsorption zone and a dehydration zone in sequence; C. High negative pressure rapid cake formation in the adsorption zone: When the filter disc is in the adsorption cake formation zone, a high negative pressure is applied to rapidly form a dense filter cake. The vacuum degree is -0.09 to -0.11 MPa, and the filter cake formation time is shortened by 30% compared with the traditional process. D. Dehydration zone control: When the filter disc enters the dehydration zone, the vacuum level is switched to medium negative pressure. The microporous structure of the capillary filter cake layer formed by dehydration is used to block air from penetrating in the opposite direction. The vacuum level is -0.06 to -0.08 MPa. The loss of ineffective air volume in the vacuum system is reduced by 60%, and the vacuum energy consumption is reduced simultaneously, which can prevent the filter cake structure from being damaged. E. Unloading and Collection: After the filter discs have completed deep dewatering, switch the vacuum level to a low-pressure maintenance vacuum or turn off the vacuum, and unload the filter cake to obtain low-moisture concentrate powder.

[0005] Preferably, the conveying method is to use a flexible hose, the surface of which is connected to a left-right swinging mechanism. The left-right swinging mechanism includes a reciprocating motor and a support. The support is fixedly connected to the output shaft of the reciprocating motor, and the flexible hose is fixedly connected to the end of the support. Through the small-amplitude reciprocating motion of the reciprocating motor, the support is driven to swing along the axis of the reciprocating motor, thereby uniformly conveying the concentrate slurry flowing out from the inside of the flexible hose to the surface of the filter disc.

[0006] Preferably, the adsorption zone and the dehydration zone are controlled independently under vacuum, and the negative pressure parameters of the two zones do not interfere with each other.

[0007] Preferably, the vacuum degree for maintaining the negative pressure is -0.04 to -0.06 MPa.

[0008] Preferably, the method is implemented through the following system: including at least two independently controlled vacuum sources, providing high negative pressure and medium negative pressure respectively, and a zone detection and control system for detecting the real-time position of the filter disk sector and controlling its connection switching with the corresponding vacuum source, and the method is applicable to the dewatering operation of iron concentrate, non-ferrous metal concentrate or fine coal slime.

[0009] Preferably, the partition detection and control system includes an angle sensor or a position sensor, a programmable logic controller, and a partition control valve assembly disposed on the vacuum pipeline.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention breaks through the limitations of traditional single vacuum degree by independently controlling the adsorption and dehydration zones of a disc vacuum filter. The moisture content of the concentrate powder is reduced by 3-5 percentage points compared to traditional single vacuum degree processes. Furthermore, the adsorption zone uses high negative pressure for rapid cake formation, shortening the cake formation time by more than 30%. This means that at the same disc filter speed, the effective dehydration time percentage increases, or the speed can be appropriately increased to achieve the same production capacity, thus improving overall processing capacity. Simultaneously, the dehydration zone uses a medium negative pressure of 0.06-0.08 MPa to avoid damage to the filter cake structure and promote the full discharge of capillary moisture. The microporous structure of the capillary filter cake layer prevents reverse air penetration, allowing the final filter cake moisture content to be reduced by 0.5-1.5 percentage points compared to traditional single vacuum degree methods within the same or shorter processing time. Moreover, the absorption of ineffective air is significantly reduced during the medium and low dehydration stages, resulting in a significant decrease in vacuum pump load and a 60% reduction in ineffective gas loss from the vacuum system, demonstrating significant energy-saving and emission-reduction benefits. Detailed Implementation

[0011] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0012] A method for reducing the moisture content of concentrate powder produced by disc filtration is based on a dual-vacuum partition modification of a disc vacuum filter. The dehydration zone of the filter is divided into independently controlled adsorption and dehydration zones, specifically including the following steps: A. Feeding and spreading: The concentrate slurry to be dewatered is evenly fed to the surface of the filter disc; B. Process Zoning: Along the rotation direction of the filter disc, the filtration working area is divided into an adsorption zone and a dehydration zone in sequence; C. High negative pressure rapid cake formation in the adsorption zone: When the filter disc is in the adsorption cake formation zone, a high negative pressure is applied to rapidly form a dense filter cake. The vacuum degree is -0.09 to -0.11 MPa, and the filter cake formation time is shortened by 30% compared with the traditional process. D. Dehydration zone control: When the filter disc enters the dehydration zone, the vacuum level is switched to medium negative pressure. The microporous structure of the capillary filter cake layer formed by dehydration is used to block air from penetrating in the opposite direction. The vacuum level is -0.06 to -0.08 MPa. The loss of ineffective air volume in the vacuum system is reduced by 60%, and the vacuum energy consumption is reduced simultaneously, which can prevent the filter cake structure from being damaged. E. Unloading and Collection: After the filter discs have completed deep dewatering, switch the vacuum level to a low-pressure maintenance vacuum or turn off the vacuum, and unload the filter cake to obtain low-moisture concentrate powder.

[0013] By independently controlling the adsorption and dehydration zones of the disc vacuum filter, the limitations of traditional single vacuum levels are broken. The moisture content of the concentrate powder is reduced by 3-5 percentage points compared to traditional single vacuum processes. Furthermore, the adsorption zone uses high negative pressure for rapid cake formation, shortening the cake formation time by more than 30%. This means that at the same disc filter speed, the effective dehydration time percentage increases, or the speed can be appropriately increased to achieve the same production capacity, thus improving overall processing capacity. Simultaneously, the dehydration zone uses a medium negative pressure of 0.06-0.08 MPa to prevent filter cake structure damage and promote the full discharge of capillary moisture. The microporous structure of the capillary filter cake layer blocks reverse air penetration, allowing the final filter cake moisture content to be reduced by 0.5-1.5 percentage points compared to traditional single vacuum methods within the same or shorter processing time. Moreover, the suction of ineffective air is significantly reduced during the medium and low dehydration stages, resulting in a significant decrease in vacuum pump load and a 60% reduction in ineffective gas loss from the vacuum system, demonstrating significant energy-saving and emission-reduction benefits.

[0014] The conveying method is to use a flexible hose. The surface of the hose is connected to a left and right swinging mechanism, which includes a reciprocating motor and a support. The support is fixedly connected to the output shaft of the reciprocating motor, and the hose is fixedly connected to the end of the support. Through the small-amplitude reciprocating motion of the reciprocating motor, the support is driven to swing along the axis of the reciprocating motor, thereby uniformly conveying the concentrate slurry flowing out of the hose to the surface of the filter disc.

[0015] The adsorption zone and the dehydration zone are independently controlled under vacuum, and the negative pressure parameters of the two zones do not interfere with each other.

[0016] The vacuum degree maintained under negative pressure is -0.04 to -0.06 MPa.

[0017] The method is implemented through the following system: including at least two independently controlled vacuum sources, providing high negative pressure and medium negative pressure respectively, and a zone detection and control system, used to detect the real-time position of the filter disk sector and control its connection and switching with the corresponding vacuum source. The method is applicable to the dewatering of iron concentrate, non-ferrous metal concentrate or fine coal slime, and has good applicability to filterable materials such as coal slime, non-ferrous metal concentrate, and chemical precipitates. It can be adapted by adjusting the zone range and vacuum degree parameters.

[0018] The zone detection and control system includes an angle sensor or position sensor, a programmable logic controller, and a zone control valve assembly installed on the vacuum line.

[0019] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for reducing the moisture content of concentrate powder produced by disc filtration, characterized in that: This is achieved by modifying a disc vacuum filter with dual vacuum partitioning, dividing the filter's dehydration zone into independently controlled adsorption and dehydration zones. The specific steps include: A. Feeding and spreading: The concentrate slurry to be dewatered is evenly fed to the surface of the filter disc; B. Process Zoning: Along the rotation direction of the filter disc, the filtration working area is divided into an adsorption zone and a dehydration zone in sequence; C. High negative pressure rapid cake formation in the adsorption zone: When the filter disc is in the adsorption cake formation zone, a high negative pressure is applied to rapidly form a dense filter cake with a vacuum degree of -0.09 to -0.11 MPa. D. Dehydration zone control: When the filter disc enters the dehydration zone, the vacuum level is switched to medium negative pressure. The microporous structure of the capillary filter cake layer formed by dehydration is used to block air from penetrating in the opposite direction. The vacuum level is -0.06 to -0.08 MPa. E. Unloading and Collection: After the filter discs have completed deep dewatering, switch the vacuum level to a low-pressure maintenance vacuum or turn off the vacuum, and unload the filter cake to obtain low-moisture concentrate powder.

2. The method for reducing the moisture content of concentrate powder produced by disc filtration according to claim 1, characterized in that: The conveying method is to use a flexible hose. The surface of the flexible hose is connected to a left-right swinging mechanism. The left-right swinging mechanism includes a reciprocating motor and a support. The support is fixedly connected to the output shaft of the reciprocating motor, and the flexible hose is fixedly connected to the end of the support.

3. The method for reducing the moisture content of concentrate powder produced by disc filtration according to claim 1, characterized in that: The adsorption zone and the dehydration zone are independently controlled under vacuum, and the negative pressure parameters of the two zones do not interfere with each other.

4. The method for reducing the moisture content of concentrate powder produced by disc filtration according to claim 1, characterized in that: The vacuum degree required to maintain the negative pressure is -0.04 to -0.06 MPa.

5. The method for reducing the moisture content of concentrate powder produced by disc filtration according to claim 1, characterized in that: The method is implemented through the following system: including at least two independently controlled vacuum sources, which provide high negative pressure and medium negative pressure respectively, and a zone detection and control system, which is used to detect the real-time position of the filter disk sector and control its connection and switching with the corresponding vacuum source. The method is applicable to the dewatering operation of iron concentrate, non-ferrous metal concentrate or fine coal slime.

6. The method for reducing the moisture content of concentrate powder produced by disc filtration according to claim 5, characterized in that: The partition detection and control system includes an angle sensor or position sensor, a programmable logic controller, and a partition control valve group installed on the vacuum pipeline.