Project Overview

Tianjin Bohua Yongli Alkali Industry Co., Ltd. upgraded the mother liquor pipeline system of its combined alkali plant to improve long-term reliability under highly corrosive and abrasive operating conditions.

Beginning in 1997, reinforced MC nylon pipes were introduced for pilot applications. In 2000, reinforced MC nylon steel composite pipes were adopted for outdoor pipe galleries and gradually expanded throughout the mother liquor system. Following the plant relocation in 2008, the upgraded piping solution became the standard material for the entire mother liquor pipeline network.

Today, the system has accumulated more than 20 years of continuous industrial service, providing a long-term reference for corrosion-resistant piping in the soda ash and combined alkali industries.

Project Background

Mother liquor in the combined alkali process contains high concentrations of chloride ions, ammonia, carbonate, and suspended solids. These operating conditions create multiple challenges for conventional pipeline materials.

Major issues included:

• Severe chemical corrosion causing premature pipe failure

• Abrasive wear from suspended solid particles

• Scale formation reducing flow efficiency

• Frequent leakage requiring maintenance shutdowns

• High annual maintenance and replacement costs

• Outdoor pipelines requiring long-span structural strength and weather resistance

Traditional materials such as cast iron, stainless steel, FRP, lined steel pipes, and PE/PO-lined pipelines experienced relatively short service life under these operating conditions.

Engineering Solution

Guangdong Kejin supplied different pipeline configurations according to installation conditions.

Indoor Process Areas

Reinforced MC Nylon Pipe

Designed for highly corrosive indoor chemical environments where excellent corrosion resistance and smooth flow performance are required.

Outdoor Pipe Galleries

Reinforced MC Nylon Steel Composite Pipe

The steel-reinforced structure provides higher mechanical strength for long-span outdoor installations while maintaining the corrosion resistance of the nylon lining.

System Coverage

The solution was gradually expanded to cover the complete mother liquor transportation system, including process transfer pipelines throughout the combined alkali production line.

Technical Advantages

Excellent Chemical Resistance

The reinforced MC nylon lining provides excellent resistance to alkaline mother liquor containing ammonia, chlorides and carbonates, reducing corrosion-related maintenance.

Improved Abrasion Resistance

The material demonstrates good resistance to slurry erosion caused by suspended particles, helping extend pipeline service life in abrasive operating conditions.

Smooth Internal Surface

The low-friction inner surface helps reduce scale adhesion and maintains stable flow characteristics over long-term operation.

Lightweight Installation

Compared with traditional metal piping, the system is lighter, simplifying transportation and installation while reducing construction workload.

Outdoor Weather Resistance

The steel composite structure combined with reinforced MC nylon has demonstrated long-term stability in outdoor installations exposed to sunlight and changing weather conditions.

Thermal Performance

The material provides lower thermal conductivity than steel, helping reduce heat loss during normal operation.

Stable Operating Temperature

Suitable for continuous service from ambient temperature up to approximately 80°C, meeting the operating requirements of typical combined alkali mother liquor systems.

Project Timeline

Year	Project Milestone
1997	Initial pilot installation of reinforced MC nylon pipes
2000	Reinforced MC nylon steel composite pipes introduced
2005	Large-scale application throughout the mother liquor system
2008	Complete pipeline system upgraded after plant relocation
2021–Present	More than 20 years of continuous industrial operation

Application Results

After long-term operation, the upgraded pipeline system has demonstrated stable performance in the combined alkali process.

Observed operating results include:

• Reduced corrosion-related pipeline failures

• Lower abrasion damage in slurry transport

• Reduced scale accumulation inside pipelines

• Fewer maintenance shutdowns

• Lower annual maintenance requirements

• Stable outdoor performance over long-term service

• Reduced overall lifecycle operating costs

Actual service life depends on operating conditions, media composition, pressure, temperature and maintenance practices.

Customer Benefits

The project helped improve the reliability of the mother liquor transportation system by reducing corrosion, abrasion and maintenance requirements.

Compared with the previous pipeline materials, the upgraded solution contributed to:

• Longer pipeline service intervals

• Lower maintenance frequency

• Reduced production interruptions

• Lower total lifecycle costs

• Improved operational stability

Key Technical Highlights

• Corrosion-resistant pipeline solution for combined alkali mother liquor

• Abrasion-resistant design for slurry transportation

• Smooth inner surface to minimize scale buildup

• Lightweight construction for easier installation

• Suitable for indoor processing areas and outdoor pipe galleries

• Long-term industrial service exceeding 20 years

• Operating temperature up to approximately 80°C

Industry

Combined Alkali Plant / Soda Ash Production

Application

Mother Liquor Transfer Pipeline

Pipe Type

• Reinforced MC Nylon Pipe

• Reinforced MC Nylon Steel Composite Pipe

Service Environment

• Corrosive alkaline solution

• Chloride-containing media

• Slurry transportation

• Indoor chemical processing

• Outdoor pipe gallery

Appendix

1. On-site pictures