Slurry pump is a large-scale centrifugal pump, which is mainly used to transport media containing abrasive solid particles. It is an indispensable general equipment in mining, chemical, coal and metal smelting industries. In the alumina production process, the slurry pump mainly transports the raw material slurry with high temperature, strong abrasiveness and large solid particle content, so it is also called the slurry pump.

Most of the slurry pumps used in alumina production at home and abroad have experienced faults such as easy wear of overflow parts, short service life, rapid equipment vibration, and rapid decline in operating efficiency. These faults will make it difficult for the slurry pump to complete the task of the rated load. , Which has a great impact on production. These failures of the slurry pump are not only related to the harsh conditions of production, but also have a lot to do with the quality of daily maintenance and overhaul of the equipment. To reduce the failure rate of the slurry pump and improve the efficiency of equipment utilization, it is necessary to use the slurry pump correctly and formulate an appropriate maintenance plan.

Classification of Common Slurry Pumps

According to the classification of the working principle, the slurry pump is a kind of centrifugal pump. The slurry pump relies on the rotation of the impeller in the pump cavity to drive the slurry to generate centrifugal force during operation, so that its energy is increased for delivery.

According to the different conveying media, centrifugal pumps can be divided into clean water pumps, solution pumps and slurry pumps; and according to the different angles of division, there are different types. According to the number of centrifugal pump impellers, they can be divided into single-stage impeller slurry pumps. And multi-stage impeller slurry pump; and according to the relative position of the slurry pump shaft and the horizontal plane, it can be divided into horizontal slurry pump and vertical slurry pump; according to the classification of the pump casing, it can be divided into single suction Slurry pump and double-suction feed slurry pump; and according to the different structure of the pump casing, it can be divided into horizontal open type and vertical combined type. Among these types, the single-stage horizontal single-suction slurry pump is the most widely used in alumina production.

The Main Factors to Be Considered in The Selection of Slurry Pump

Due to the balance of many factors such as flow, pressure, viscosity, abrasiveness, particle size and particle type, choosing the right slurry pump for your slurry application can be a complex task. Application engineers who know how to take all these factors into consideration can be of great help.
When determining which slurry pump is best for your specific application, follow these four simple steps.

1.Determine the size of the slurry pump

The most important thing here is to calculate the pump horsepower required to deliver a specific fluid flow under the required or required pressure difference. Please see the following:
● The concentration of solids in the slurry-measured as a percentage of the total volume.
● The length of the pipe. The longer the pipe, the greater the friction caused by the mud that the pump has to overcome.
● Diameter of slurry pipe.
● Static head-the height to which the mud must be raised in the pipeline system

2.Determine the nature of the material being pumped by the slurry pump

● Consider the particle size, shape and hardness (the possibility of affecting the wear and corrosion of pump components)
● The corrosiveness of the slurry.

3.Consider the components of the slurry pump

● If it is a centrifugal pump, is the design and material of the impeller suitable for pumping mud?
● What are the materials used to build the pump? Advanced alloys such as AL-6XN or Hastelloy C-22 are most suitable for pumping highly abrasive muds.
● Are the pump discharge parts suitable for the pumped mud?
● What is the best sealing arrangement for the application?
● Will solid particles pass through the pump?
● How much solid damage can the customer tolerate?
It is also important to consider the chemical compatibility of the slurry with any elastomers in the pump. Once you have resolved the nature of the mud and the components of the different types of pumps, you can select potential candidate mud pumps for your application.

4.Determine the operating parameters of the slurry pump

To reduce component wear, most centrifugal slurry pumps run at fairly low speeds—usually below 1200 rpm. Find the best location that allows the pump to run as slow as possible but fast enough to prevent solids from settling out of the slurry sediment and clogging the pipeline.
Then, reduce the pump discharge pressure to the lowest possible point to further reduce wear. And follow the correct pipeline layout and design principles to ensure that the mud is continuously and evenly delivered to the pump.
The correct selection is the basis to ensure the long-term and good operation of mechanical equipment after it is put into use, and it is also a prerequisite for meeting production requirements. The correct selection according to the production requirements can ensure the stable operation of the slurry pump with high efficiency and low failure, and the service life of the wearing parts can be extended, thereby ensuring the stable operation of the production process.
Since the application conditions of slurry pumps are more severe than those of ordinary equipment, and the impact of slurry pumps on production is greater, in addition to fully considering the economy, technology and applicability of equipment selection, On this basis, a more wear-resistant and higher specification slurry pump should be selected, especially the safety factor in terms of rated flow can be increased appropriately, so as to avoid long-term high-frequency operation of the slurry pump after operation. It has a very large impact on reducing the failure rate of slurry pumps.