Slurry Pump Parts Materials

Slurry pumps are used widely throughout the beneficiation section of the mining industry where most plants utilise wet separation systems. These systems usually require the movement of large volumes of slurry throughout the process.

Slurry pumps are also widely used for the disposal of ash from thermal power plants. Other areas where slurry pumps are used include the manufacture of fertilisers, land reclamation, mining by dredges, and the long distance transportation of coal and minerals.

Increased global focus on environmental and energy constraints will certainly generate much wider uses for slurry pumping in years to come.

Slurry Pump Wet Parts is directly connection with slurries, They are very crucial to the service life. The wetted parts include impeller, volute liner, throatbush, frame plate liner insert, cover plate liner, frame plate liner and casing etc., These parts are very easily worn-out components because they work under longtime impact of abrasive and corrosive slurries in site. For the long service life of pump parts, the material plays an important role here.

Selection of the type of materials to be used for slurry pumping applications is not a precise procedure. The procedure must first account for all the factors (variable characteristics) of the particular slurry. The procedure must take into account the constraints imposed by the following:

1. type of slurry pump,
2. slurry pump speed,
3. options within the range of the models available.

The basic data required to make a selection of the type of material is:
1. the particle sizing of the solids to be pumped,
2. the shape and hardness of these solids, and
3. the corrosive properties of the “liquid” component of the slurry to be pumped.

The material selection for the pump liners and impellers is made from two basic types of materials:
1. High chrome alloys (A05, A07, A12, A21, A33, A49, A51, A61, A68)
2. Natural Rubber or Elastomers (R08, R24, R26, R33, R55, R56, S01, S02, S12, S21, S31, S42, S45, S51)
3. Polyurethane (U01, U02, U38, U15A)
4. Ceramic (Y07, Y08)

HIGH CHROME ALLOYS
Wear resistant cast alloys are used for slurry pump liners and impellers where conditions are not suited to rubber, such as with coarse or sharp edged particles, or on duties having high impeller peripheral velocities or high operating temperatures.

NATURAL RUBBER ELASTOMERS
Natural Rubber
1. Excellent erosion resistance for liners (against solids up to 15mm size), but limited to particles of 5mm size for impellers.
2. May not be suitable for very sharp edged solids.
3. May be damaged by oversized solids or trash.
4. Impeller peripheral speed should be less than 27.5 m/s, to avoid the thermal breakdown of the liner, adjacent to the outer edge of the impeller. (Special formulations are available to allow speeds up to 32 m/s in certain cases).
5. Unsuitable for oils, solvents or strong acids.
6. Unsuitable for temperatures in excess of 77°C.

Synthetic Elastomers: Neoprene, Butyl, Hypalon, Viton A and others
These are used in special chemical applications under the following conditions:
1. Not as erosion resistant as natural rubber.
2. Have a greater chemical resistance than natural rubber or polyurethane.
3. Generally allows higher operating temperature than natural rubber or polyurethane.

POLYURETHANE
1. Used for pump side liners, where the peripheral speed of the impeller is higher than 27.5 m/s, (and precluding the use of standard rubber) and used for impellers where occasional trash may damage a rubber impeller.
2. Erosion resistance is greater where erosion is of a sliding bed type rather than one of directional impact. (See Figure 2-2).
3. Has less erosion resistance to fine solids than natural rubber. Has greater erosion resistance to coarse sharp edged particles than natural rubber, in some circumstances.
4. Unsuitable for temperatures exceeding 70°C and for concentrated acids and alkalies, ketone, esters, chlorinated and nitro hydrocarbons.

CERAMIC
The biggest characteristic of ceramic slurry pump parts is both wear-resisting and corrosion-resisting, and the performance is far higher than metal lined pump and rubber lined pump.
Through many tests and data feedback in metal concentrating plant for many years, the service life of ceramic slurry pump is generally 3-6 times of that of High chromium alloy pump under the same working condition, and the price of silicon carbide material is lower than that of high chromium steel, duplex steel, and so on, so that the ceramic slurry pump in raw material prices compared with the first-class alloy also has a great economic advantage.
1. Corrosion resistance
Unlike metal pumps, ceramic pump wet end components (impeller, throat bush, frame plate liner insert, volute) are mainly composed of silicon carbide inorganic non-metallic materials, with excellent acid and alkali resistance, oxidation resistance.
2. Wear resistance
The wet end parts of slurry pump will produce corresponding wear while transferring the media contains solid particles. The crystalline structure of Silicon Carbide is similar to that of Diamond Tetrahedron. It is a compound mainly bonded by covalent bond. Its hardness is second only to diamond.
3. Heat resistance
Because the material is not easy to be deformed or corroded when it is heated, tested by Tobee, the ceramic slurry pump is put in the liquid with the highest temperature of 120 °C for 7 days. For the general working condition below 60 °C, Silicon Carbide ceramics can be completely satisfied.
4. Shock Resistance
The impact strength of Silicon Carbide ceramics treated by special process can reach 80 times of that of common ceramics, which can be used in slurry pump with solid granule.