How Nylon & Steel-Lined Nylon Pipes Eliminated Corrosion and Crystallization in Zinc Electrolysis

2026-05-09

Project Overview

To address severe corrosion and crystallization problems in zinc electrolysis pipelines, Guangdong Kejin New Materials Co., Ltd. partnered with Chifeng Zhongse Kubo Hongye Zinc Industry Co., Ltd. on a pilot project to evaluate the performance of DN125 reinforced nylon pipes and DN125 steel-lined nylon composite pipes in waste electrolyte transportation.

The trial started in October 2007, with phased inspection completed in March 2008. The project demonstrated that nylon-based composite piping could operate reliably in highly corrosive, crystal-forming process conditions, providing a practical alternative to conventional metal pipelines.

Customer Challenge

The electrolysis workshop transports waste electrolyte containing sulfuric acid under continuous operation. Conventional carbon steel pipelines experienced several recurring issues that increased maintenance costs and reduced production efficiency.

1. Severe Corrosion

The waste electrolyte contained approximately 160–180 g/L sulfuric acid at around 40°C.

Under these operating conditions, traditional metal pipes gradually suffered wall thinning, corrosion, leakage, and unexpected shutdowns.

2. Frequent Crystal Build-Up

Electrolyte salts tended to crystallize on the rough inner surface of metal pipes.

Over time this resulted in:

Reduced flow capacity
Pipeline blockage
Frequent cleaning shutdowns
Increased maintenance costs

3. High Installation Costs

Traditional steel pipelines required lifting equipment and welding during installation.

This resulted in:

Longer installation time
Higher labor costs
Production interruptions during replacement

Project Objectives

The customer was looking for a pipeline solution capable of:

Excellent sulfuric acid corrosion resistance
Reduced crystallization and scaling
Longer service life
Faster installation
Lower lifecycle maintenance costs
Stable operation in electrolysis applications

Solution Provided

Guangdong Kejin supplied a complete pilot piping system including:

Product	Specification	Application
Reinforced Nylon Pipe	DN125 × 3 m	Standard pipeline sections
Steel-Lined Nylon Composite Pipe	DN125 × 6 m	Higher pressure pipeline sections
Nylon Elbow	DN125 × 90°	Direction changes

The trial installation was carried out on the waste electrolyte transfer line in the electrolysis section.

Pipeline performance was continuously monitored throughout the evaluation period.

Why Reinforced Nylon Pipe?

Outstanding Corrosion Resistance

Reinforced nylon is highly resistant to sulfuric acid and many other aggressive chemical media.

Unlike conventional steel pipelines, the material does not rust, corrode, or deteriorate during long-term service.

Smooth Inner Surface Reduces Crystallization

One of nylon's major advantages is its naturally smooth, low-friction inner wall.

Benefits include:

Lower crystal adhesion
Reduced scaling
Improved flow efficiency
Less pipeline cleaning
Lower risk of blockage

Lightweight Installation

Compared with steel piping, reinforced nylon pipes are significantly lighter.

Advantages include:

Easier transportation
Faster installation
Reduced lifting equipment
Lower labor costs

Excellent Wear Resistance

The material also offers high abrasion resistance, making it suitable for continuous slurry and chemical transportation.

Why Steel-Lined Nylon Composite Pipe?

For applications requiring higher mechanical strength, Kejin supplied steel-lined nylon composite pipes.

These combine:

Steel outer pipe for structural strength
Nylon inner liner for corrosion protection

The composite structure provides:

Higher pressure capability
Better impact resistance
Excellent corrosion resistance
Reduced maintenance
Longer service life

Project Results

After approximately five months of operation, inspection showed excellent pipeline performance.

Inspection Findings

During the March 2008 inspection:

Inner pipe surfaces remained smooth and intact
No measurable corrosion was observed
No significant wear was detected
Pipeline integrity remained excellent

Operational Improvements

Compared with conventional metal pipelines, the customer experienced:

Significantly reduced crystal accumulation
Elimination of frequent blockage problems
More stable continuous production
Lower maintenance requirements

Economic Benefits

The project generated measurable operational advantages:

Lower installation costs
Reduced maintenance frequency
Longer service life
Fewer production interruptions
Lower total cost of ownership (TCO)

Customer Validation

Following the pilot project, the customer issued an official trial evaluation confirming that both reinforced nylon pipes and steel-lined nylon composite pipes met the operating requirements of the electrolysis process.

The successful trial provided technical confidence for future pipeline upgrades across similar production systems.

Key Technical Advantages

Corrosion Protection

Designed for aggressive chemical environments where conventional steel pipelines suffer rapid degradation.

Reduced Crystallization

The smooth nylon lining minimizes crystal adhesion and helps maintain stable flow.

Complete Product Portfolio

Kejin provides solutions for different operating conditions:

Reinforced nylon pipes for standard chemical service
Steel-lined nylon composite pipes for higher pressure applications

This allows customers to optimize both performance and investment.

Lower Lifecycle Cost

Compared with traditional metal pipelines, nylon-based piping systems can reduce overall operating costs through:

Longer service life
Lower maintenance
Reduced downtime
Faster installation
Improved production efficiency

Applications

This solution is suitable for industries handling corrosive or crystal-forming fluids, including:

Zinc smelting
Copper smelting
Nickel processing
Hydrometallurgy
Sulfuric acid systems
Chemical processing
Chlor-alkali plants
Soda ash production
Mining process pipelines

Conclusion

This pilot project demonstrates that reinforced nylon pipes and steel-lined nylon composite pipes can provide a reliable alternative to conventional metal piping in zinc electrolysis applications.

By combining excellent corrosion resistance, reduced crystallization, lightweight installation, and long service life, the solution helps industrial plants improve reliability while reducing maintenance costs and overall lifecycle expenses.

For facilities seeking to upgrade chemical process pipelines, nylon composite piping offers a proven engineering solution for demanding corrosive environments.