Slurry Pump Wear Reasons and Commonly Used Wear-Resistant Materials

Slurry pump is widely used in hydraulic, electric power, mining and other industries to carry out the hydraulic transport of solid materials such as sediment, ash slag, concentrate and tailings. The flow parts are the main wear parts, including impeller, volute, backplate and so on. Its wear is a very complex physical and chemical process, which causes a large amount of material consumption, increases maintenance costs, and reduces production efficiency and economic benefits. This article will analyze the wear reasons of slurry pump and the common wear resistant materials.

There are many wear factors of slurry pumps, and the wear mechanisms of different parts are not the same, but generally can be summarized into the following three categories:

(1) Erosion Wear

During the operation of slurry pump, solid particles carried in the liquid impact on the surface of flowing parts at a certain speed, resulting in material loss. According to the analysis of the worn surface of the failed component, the erosion wear mechanism can be divided into cutting wear, deformation fatigue wear and cutting and deformation combined wear.

(2) Cavitation Wear

In the operation of the pump, the local area of the flow parts (usually the impeller inlet later), for some reason, the absolute pressure of the liquid into the drop to the vaporization pressure of the temperature at that time, the liquid will begin to vaporize, produce vapor, and forms bubbles. These bubbles flow forward with the liquid, and when they reach a certain high pressure, the bubbles shrink sharply and even collapse. While the bubbles are condensing, the liquid particles fill the voids at a high speed and have a strong impact on the metal surface. Metal surface fatigue and peeling, resulting in material loss. When severe, the metal surface appears honeycomb. Usually, the parts where cavitation occurs are at the outlet of the impeller and the inlet of the volute.

(3) Corrosive Wear

When the conveyed medium has a certain pH, the flow parts of the slurry pump will also undergo corrosion and wear, that is, the loss of materials under the combined action of corrosion and wear. Corrosion can be divided into chemical corrosion and electrochemical corrosion. Chemical corrosion is the direct reaction between metal and liquid medium to cause metal loss. Electrochemical corrosion refers to the formation of micro-batteries on the surface of the metal under the action of a liquid medium to cause material loss.

The wear-resistant materials commonly used in slurry pumps are metal wear-resistant materials, ceramics and rubber. Each material has different wear characteristics, and also has its adaptable investment return economy. When choosing materials, you cannot simply consider the initial investment of the pump.

Metal wear-resistant materials are mostly used in the beneficiation and ore processing industries where the slurry contains coarse and sharp. In general, the hardness of the alloy determines its resistance to particles. High shear hardness and compressive strength will improve the wear resistance of pump parts. Metal materials commonly used in slurry pumps are shown in Table 1.

Table 1 Metal Material Commonly Used for Slurry Pump

(2) Ceramic Surface Coating

Although ceramic materials have high hardness, wear resistance, corrosion resistance and other characteristics. However, due to its brittleness, it is difficult to be widely used in slurry pumps. However, the method of surface coating is adopted to form a ceramic coating on the metal surface, which not only exerts the wear resistance and corrosion resistance of ceramic materials, but also improves the service life of metal materials. However, there are still many problems to be solved in practical applications. 

(3) Rubber Material

There are two types of rubber materials: natural rubber and synthetic rubber. Rubber can be applied to pump slurry with particles smaller than 10mm (average particle size 3mm). Its abrasion resistance is better than that of metal materials. Therefore, rubber pumps are mostly used when transporting fine particle slurry without edges and corners. At present, the representative one is the wear-resistant rubber slurry pump produced by Shandong Xinhai Mining Technology & Equipment Inc. The natural rubber content is about 95%, the wear resistance index is high, and the service life is long. The overall effect in the mining industry is better than that of metal and ceramic slurry pumps. The abrasion resistance and application conditions of rubber are shown in Table 2.

Table 2 Rubber Materials Commonly Used for Slurry Pump

The above is the three wear factors and common wear-resistant materials of slurry pump. When purchasing slurry pump, it is necessary to comprehensively consider the application of slurry properties, working temperature and other factors to select suitable wear-resistant materials. You can also consult a professional slurry pump manufacturer to strive for greater economic benefits.