• Industrial filter cloth, vertical plate filter press, chemical filtration of alumina
  Filter press type: Vertical plate filter press
  Application industry: Chemical industry
  Material description: Alumina
  Filter cloth model: 2015

Application research of industrial filter cloth in vertical plate filter press for chemical filtration —— Taking alumina processing as an example

I. Preface

In the modern chemical industry, solid-liquid separation is the core of many key processes. Especially in alumina production processes, filtration technology directly affects product quality, production efficiency, and environmental compliance. The alumina extraction process contains a large amount of high-concentration, high-temperature, and highly corrosive solid-liquid mixtures, which are difficult to handle and place extremely high demands on filtration equipment and materials.

Vertical plate filter press As equipment that has rapidly developed in the chemical separation field in recent years, it has advantages such as small footprint, high pressing force, and high degree of automation, and is particularly suitable for the deep filtration of fine chemical materials such as alumina, titanium dioxide, and inorganic salts. As the direct medium for filter cake formation and liquid separation, industrial filter cloth performance and adaptability play a decisive role in the entire filtration system.

This article takes the alumina industry as an example to analyze the process characteristics of vertical plate filter presses, explore the key role of industrial filter cloths in them, and combine application practices to demonstrate the technological advantages of high-performance filter cloths in improving filtration efficiency and system stability.

II. Filtration stage in alumina production

The main production method of alumina is the Bayer process, and its core process includes:

• Alumina ore calcination and alkali leaching;
• Red mud separation;
• Solution purification;
• Seed precipitation;
• Finished product roasting.

Among them, " Red mud separation ” and " Seed washing ” In these two stages, large-scale, high-precision solid-liquid separation operations are involved. Taking red mud separation as an example, its main goal is to separate insoluble residue from the strongly alkaline slurry to ensure the purity of the mother liquor and the stability of the subsequent process. Seed washing requires the filter cloth to maintain high permeability while effectively preventing crystal loss.

Due to the extremely fine, highly corrosive, and high-concentration processing medium particles, a high-pressure, stable, and efficient filtration system is required. At this time, vertical plate filter press with special industrial filter cloth has become one of the keys to ensuring the effectiveness of system operation.

III. Working principle and characteristics of vertical plate filter press

Vertical plate filter press is a type of high-efficiency filter press that has developed rapidly in recent years. It is usually composed of multiple vertically stacked filter plates, equipped with automatic alignment, clamping, and cake unloading systems, and is widely used in mining, chemical, and environmental protection fields.

Its main characteristics include:

• High-pressure filtration ：Operating pressure up to 1.2~2.0MPa ，which is conducive to the dehydration of fine-grained materials;
• Vertical structure, compact footprint ：Gravity self-flow drainage, which is conducive to installation and system integration;
• High degree of automation ：It has functions such as automatic feeding, clamping, and filter cake removal;
• Suitable for highly corrosive and high-temperature media ：Widely used in the fields of alumina and sulfuric acid titanium dioxide.

Vertical plate filter presses have strict requirements for filter cloths, especially in terms of filtration accuracy, pressure resistance, mud cake stripping, and corrosion resistance. It is necessary to use mature special industrial filter cloth 。

IV. The key role of industrial filter cloth in vertical plate filter press

In the vertical plate filter press system, the filter cloth mainly undertakes the following functions:

1.  Solid-liquid separation

The filter cloth needs to have suitable filtration accuracy, which can efficiently retain fine particles while ensuring that the filtrate flows out smoothly, preventing overpressure or clogging of the filter press system.

2.  Filter cake formation and stripping

The mud cake formed after high-pressure extrusion needs to have good integrity, and the filter cloth should be able to smoothly achieve automatic filter cake shedding, reducing manual intervention and equipment wear.

3.  Withstand mechanical and chemical double challenges

In alumina production, the filter cloth needs to withstand alkaline materials, high-temperature liquids ( 60°C~90°C ) and high-intensity mechanical extrusion for a long time. The material must have excellent chemical resistance, heat resistance, and tensile strength.

V. Xiamen Citius (Xiamen Citius) Advantages of filter cloth application in the alumina industry

As a national high-tech enterprise and a standard-setting unit in the filtration materials industry, Xiamen Citius (Xiamen Citius) Filtration Materials Technology Co., Ltd. With extensive experience in filter cloth applications in the alumina and fine chemical industries, we have launched a series of high-performance industrial filter cloths compatible with vertical filter presses, which have been widely recognized.

The advantages of our filter cloths include:

（ 1 ）Excellent filtration and permeability

The fabric structure is optimized for the particle size distribution of alumina slurry, using high-density monofilament weaving and composite filter layer design to ensure high throughput and low residue.

（ 2 ）Strong alkali resistance and high-temperature resistance

Selected alkali-resistant polyamide fibers, or PTFE modified treatment, effectively cope with the high alkali and high temperature environment in Bayer process production, and extend the service life of filter cloth.

（ 3 ）High mechanical strength and dimensional stability

Using directional reinforcement technology and pre-shrinking heat setting technology to enhance the tensile strength and structural stability of the filter cloth to meet the high-pressure operation requirements of vertical filter presses.

（ 4 ）Customizable processing and services

Xiadias (Xiamen Citius) Can customize filter cloth size, edging, hole opening, guide belt installation, etc., according to customer equipment model and process parameters, to ensure rapid on-site replacement and long-term stable operation.

VI. Typical Case: Significant Effectiveness of Alumina Enterprise Filter Cloth Replacement

A large domestic alumina enterprise, when using a foreign brand filter cloth, experienced frequent filter cloth blockage and decreased filtration efficiency due to poor alkali solution adaptability and difficult mud cake separation. After switching to Xiadias (Xiamen Citius) provided customized industrial filter cloth, the results after 3 months of operation are as follows:

• Filter cake moisture content reduced by 3%-5% ，improving subsequent calcination efficiency;
• Filter cloth service life increased from the original average of 90 days to 150 days or more ；
• Replacement time shortened, equipment downtime reduced by approximately 30%；
• Filtrate clarity improved, reducing mother liquor loss 。

This project successfully verified the significant advantages of high-performance industrial filter cloths in alumina filtration.

VII. Conclusion

In chemical filtration processes that prioritize efficiency and stability, industrial filter cloths play an indispensable role. Especially in vertical filter press applications, facing the challenges of highly corrosive and high-precision alumina materials, the quality of the filter cloth directly determines the separation quality, system operation, and economic benefits.

Xiamen Citius (Xiamen Citius) As a leading enterprise in the field of filtration materials, we will continue to focus on technological innovation and customized development of filter cloths for different process needs, providing the chemical industry with smarter, more reliable, and more environmentally friendly filtration solutions to support the high-quality development of China's alumina industry.