• Application of filter cloth for horizontal vacuum belt filter in chemical alkali plant waste residue and wastewater
  Filter type: Horizontal vacuum belt filter
  Application industry: Chemical industry
  Material description: Alkali plant waste residue and wastewater
  Filter cloth model: 15P

Stable “ Filter ” Introduction: Key application of industrial filter cloth in the treatment of waste residue and wastewater in chemical alkali plants

In the modern chemical industry, alkali plants, as important production units of basic inorganic chemicals, undertake the large-scale manufacturing of products such as caustic soda ( NaOH ), soda ash ( Na ₂ CO ₃ ), and potassium hydroxide ( KOH ) etc. With the production of these products, a large amount of by-product waste residue and wastewater is also generated, showing strong alkalinity, high salt content, fine particles, high corrosiveness and other typical characteristics, posing great challenges to process equipment and environmental protection systems. How to improve the treatment capacity of wastewater and waste residue while ensuring production efficiency is a key technical issue facing many alkali plants.

In this treatment system, industrial filter cloth as the “ core filtration medium ” in solid-liquid separation equipment, its selection and performance directly determine the dehydration efficiency, filter cake quality, filtrate clarity, and equipment operation stability. This article will focus on the specific application scenarios, process requirements, material selection, and engineering cases of industrial filter cloth in the treatment of waste residue and wastewater in alkali plants, and analyze its “ filtration approach ”。

in a highly corrosive environment.

I. Process characteristics of alkali plant waste residue and wastewater

• Common production processes in alkali plants include the ammonia-soda process, the combined alkali process, and the electrolytic process. Different processes will produce by-products with different properties, mainly including: Lime slag
• : such as insoluble residue after the reaction of lime milk and carbon dioxide in the ammonia-soda process, with high water content, fine particles, and high processing difficulty; Salt mud
• : a high-salt-content particulate mixture formed after multiple evaporative crystallizations of the mother liquor; Desulfurization by-products : such as desulfurization gypsum or desulfurization ash produced in the process of alkali absorption of flue gas ₂ SO
• during concentrated alkali wastewater : containing unreacted alkali, dissolved salts, and fine particulate impurities, pH often above 11-13

，with strong corrosiveness and viscosity. These waste residue and wastewater are often dewatered and separated by belt press filter, plate and frame filter press, vertical filter press, vacuum belt filter etc. Due to the complex operating conditions and harsh media, it puts extremely high demands on the filtration medium —— etc. Due to the complex operating conditions and harsh media, it puts extremely high demands on the filtration medium filter cloth

。

1.  II. The key role of industrial filter cloth in the treatment of waste residue and wastewater “ Filter cloth is not only a medium, but also a ”

magnifier

• of system performance. In the solid-liquid separation process of alkali plants, filter cloth undertakes multiple tasks such as particle retention, liquid permeability, filter cake stripping, and pressure resistance. An excellent filter cloth can:
• Significantly improve the dehydration speed and shorten the equipment operation cycle;
• Increase the filter cake dryness and reduce the subsequent transportation and processing costs;
• Reduce the content of suspended solids in the filtrate, optimize wastewater reuse or discharge;

2.  Extend the service life of the equipment and reduce the frequency of operation and maintenance.

Filter cloth selection should fully match the process medium

Currently, the more commonly used filter cloth materials include Polypropylene ( PP ), Polyester ( PET ), Polyamide ( PA ), PTFE (fluoropolymer) ，and combined with different fabric structures such as monofilament, double-layer, satin, and twill.

III. Typical Application Scenarios Analysis

Scenario 1: Lime Sludge Dewatering —— Belt Press +  Alkali-resistant filter cloth

Lime sludge dewatering is a routine process in soda ash plants. This material has fine particles, high water content, and strong viscosity. Using belt press filter with double-layer monofilament filter cloth ，continuous dewatering operation can be achieved.

Recommended filter cloth characteristics ：

• Satin weave, enhances filter cake release;
• Monofilament structure, uniform pore size, good backwashing regeneration;
• Surface PTFE coating treatment, further enhances alkali resistance and anti-scaling ability.

Scenario 2: Salt Mud Treatment —— Plate and frame filter press +  High-density filter cloth

Salt mud has a high solid content, but the particle size is uneven, and some impurities have strong adhesion. Using polypropylene high-density woven filter cloth ，it can retain fine particles while maintaining good air permeability.

Recommended filter cloth model ：Xiamen Citius (Xiamen Citius)PP5210 、PP3615 ，etc., with strong compressive strength and long service life.

Scenario 3: Waste Liquid Purification —— Vacuum belt machine +  Corrosion-resistant thin-layer filter cloth

Suspended impurities need to be removed before mother liquor recovery. Using vacuum belt filtration system combined with thin-layer, high-permeability filter cloth can improve the cleanliness of the filtrate and reduce the subsequent crystallization load.

Technical Key Points ：

• The filter cloth needs to have micrometer-level filtration capability ( 5-15μm );
• High-throughput design to avoid liquid retention;
• Can be used with an automatic cleaning system to improve operating efficiency.

IV. Xiamen Citius (Xiamen Citius) ：Provides system solutions for alkali plant filtration processes

As a leading enterprise in the research and development and manufacturing of industrial filtration systems in China, Xiamen Citius (Xiamen Citius) Filtration Materials Technology Co., Ltd. has been deeply involved in the chemical separation industry for more than 30 years and has accumulated rich technical experience and product resources in the field of alkali plant waste residue and waste liquid treatment.

Technical advantages include:

• Provides coverage of 400+ filter cloth models customized solutions to match various filter presses, belt filters, vacuum belt machines, etc.;
• Introducing high-strength yarn raw materials, nanometer-level finishing technology, and anti-scaling treatment technology ，to improve the stability and durability of the filter cloth;
• Support personalized processing services such as filter cloth cutting, edging, punching, gluing, and guide strips ，to ensure installation compatibility;
• Owning a complete database of typical alkali plant cases ，can quickly match application models and debugging parameters for customers.

Engineering Case Examples:

• Transformation of the lime sludge dewatering system of a large-scale combined alkali enterprise. After using Xiamen Citius (Xiamen Citius)PA1422 filter cloth, the filter cake dryness increased from 47% to 61% ，and the equipment failure rate decreased 30%；
• Upgrade of the salt mud filtration system of a soda ash plant in East China. The original domestic PET cloth frequently clogged, and after replacing it with Xiamen Citius (Xiamen Citius)PP double-layer filter cloth, the operation has been stable for over 18 months.

V. Conclusion: Creating Value in Challenges “ Filter ” Creating Value

Facing tightening environmental policies, increasing resource recycling requirements, and multiple pressures to reduce energy consumption and production, alkali plants have higher requirements for waste residue and wastewater treatment systems. Industrial filter cloths are no longer just consumables, but are integral to the entire solid-liquid separation system. “ core component ” Its performance determines the efficiency and sustainability of the treatment process.

In this process, choosing a filter cloth supplier with technical accumulation, material research and development, customization capabilities, and application experience is key to the alkali plant's achieving green and efficient operation. Xiamen Citius (Xiamen Citius) is willing to leverage its thirty years of technical accumulation to help chemical enterprises steadily advance in complex working conditions, “ Filter ” creating value for the future.

For further information on filter cloth solutions for chemical alkali plants, please contact:

• 📧 Email: wyl@citius-filter.com
• 🌐   Website : https://www.citius-filter.com
• 📱 WhatsApp: +86-13950107241