Fine filtration project for pigment suspensions of a chemical enterprise in Jalisco State, Mexico

This enterprise produces various synthetic pigments. Among them, the red and blue pigments form high-value suspensions after the synthesis reaction. The solid pigment particles need to be separated from the liquid phase. The filtrate can be reused, and the filter cake, after drying, is packaged and sold. The characteristics of the suspension are: neutral pH (6.8-7.2), normal temperature (20-25℃), low viscosity (about 150 cP), and a solid content of approximately 18%. It is required that the solid content in the filtrate after filtration be lower than 50 ppm, and the recovery rate of pigment particles should be no less than 98%.

The particle size of the pigments is between 5 and 15 micrometers. The original centrifugal separation method resulted in severe leakage, and the recovery rate was only 92%.

The moisture content of the material discharged by the centrifuge is approximately 35%, and the energy consumption for subsequent drying is high.

The production batches are frequently switched, and different colored pigments must not be contaminated with each other. The cleaning and replacement of the filter cloth take a lot of time.

Based on the communication information, we recommend the use of the XMZ80/870-30 fully automatic box-type filter press and have made targeted configurations:

The filtration area is 80 square meters, and the volume of the filter chamber is 1200 liters. It can meet the processing requirements for 8 to 10 tons of slurry per batch.

The filter plate is made of PP material, which is resistant to the weak acidic and alkaline components in the pigments. It adopts a central feeding method, and the feeding port is lined with PP to prevent corrosion.

The filter cloth is made of 10-micron PP non-woven fabric, which can achieve efficient filtration for particles ranging from 5 to 15 microns.

The feed pressure is set at 0.6 megapascals to prevent the fine particles from being clogged by excessively high pressure.

The clear water channel design makes it convenient to check the liquid color of each filter plate when switching between different paint batches, and to determine if there is any leakage or residue.

The rack is coated with a grey-white corrosion-resistant paint layer, which is suitable for the humid environment of the pigment workshop.

Evaluation of the equipment's performance after six months of operation:

Filtering accuracy meets the standard: The actual measured solid content of the filtrate is 25-40 ppm, which is better than the 50 ppm standard required by the customer. The recovery rate of pigment particles has increased to 98.7%.

Reduced moisture content of the filter cake: The moisture content of the filter cake decreased from 35% in the centrifuge to 22%. The energy consumption for subsequent flash drying was reduced by approximately 18%.

Batch switching efficiency improvement: The clear water trough design enables operators to complete the liquid discharge inspection of all filter plates within 5 minutes. After confirming no residue, they can switch to the next color batch. This results in a 70% reduction in cleaning time compared to that of the centrifuge.

Automation-based staff reduction: In the original centrifugation process, 2 people were required to operate per shift. After the installation of the filter press, each shift only requires 1 person for inspection and filter cloth checks. The other employee was transferred to the packaging process.

Operational stability: No downtime occurred for six consecutive months. The average service life of the filter cloth is 85 cycles (approximately 4 months), exceeding the customer's expectations.

The customer's production supervisor stated during the equipment acceptance process that this filter press not only addressed the issues of filtration accuracy and recovery rate, but more importantly, it enabled the automation upgrade of the pigment production line, laying the foundation for subsequent expansion and standardized management. Currently, the customer has planned to purchase the same model of equipment for another production line.