Replacement of Centrifugal Pumps with Ceramic Plunger Pumps
Project Address:CNNC Guyuan Uranium-Molybdenum Mine Mineral Liquid Separation Project
Detailed Introduction
Material Characteristics: After the raw ore is processed by a ball mill, sulfuric acid, hydrogen peroxide, and carbide slag are added to form a slurry containing sand particles. This slurry exhibits strong corrosiveness, which ordinary steel cannot withstand. The mixing of this material is carried out using high-temperature and high-pressure thermal steam, and the temperature of the material can reach 75°C. All pipes and valve materials are made of 316 stainless steel.
Usage Status of the Original Centrifugal Pumps:Two centrifugal pumps driven by high-power motors are used to feed six 800-square-meter diaphragm filter presses. The two pumps operate in a "one in use, one on standby" mode, with a feeding pressure of 6.5 kgf/cm² (kilograms-force per square centimeter). Due to variations in the condition (new or old) of the filter cloth and the concentration of the material, the feeding time of the centrifugal pumps ranges from 30 minutes to 60 minutes. The initial flow rate is 200 cubic meters per hour, which gradually decreases until the pumps are shut down.
Owing to the special nature of the material, the centrifugal pumps require maintenance once a week and an overhaul every two weeks. For each overhaul, the cost of replacing the impellers, pump casings, and mechanical seals ranges from 8,000 to 10,000 yuan. This results in a monthly cost of 16,000 to 20,000 yuan and an annual operating cost of 200,000 to 250,000 yuan. Additionally, each maintenance operation requires at least two personnel; sometimes, four people are needed to collaborate, and the maintenance usually takes approximately three hours.
Subsequent Usage of Ceramic Plunger Slurry Pumps
A YB400-120 ceramic plunger slurry pump is used to feed six 800-square-meter diaphragm filter presses. The set pressure is 6.5 kgf/cm². When starting to feed, the ceramic plunger runs at a high frequency. When the set pressure is reached, the frequency of the ceramic plunger gradually decreases, that is, the motor speed slows down, making the motor more energy-efficient. According to the newness or oldness of the filter cloth and changes in material concentration, the feeding time ranges from 30 to 60 minutes, with the initial flow rate being 120 cubic meters and gradually decreasing. Due to the characteristics of the material, which contains sand and has strong corrosiveness, it causes great damage to the rubber valve plates in the 4 one-way valves of the plunger pump and the rubber seals of the ceramic plunger. The 4 rubber valve plates are replaced once a month, and the rubber seals are replaced once every 20 days. Each replacement costs 4,000 to 5,000 yuan, so the annual maintenance cost is about 60,000 yuan. Each maintenance requires 1-2 people and takes 1-2 hours.
Comprehensive Evaluation:
When the plunger pump and the centrifugal pump have almost the same feeding operation time, the annual maintenance cost and maintenance time of the plunger pump are only one-fourth of those of the centrifugal pump.
