Jaw liners are normally Mn-steel liners with 12-14 % Mn to withstand impact and abrasion resistance. With proper selection and design of the system, life of jaw plates may be enhanced. Preferably discharge height should be optimum and jaw lines should be such that it can be repositioned so that the wearing of jaw plate s more uniform before discarding.

Apart from the steps mentioned above as impact is one of the prime reasons for reduction in jaw life, the provision of a thick, replaceable deflector plate can protect the top of the moving jaw from the impact of the feed material and thereby extend life of the jaw plates.

The material and the process procedure of the material are the most crucial points.

Is there proper jaw plate design to allow choke feeding without bogging a jaw crusher?

There are various designs available for the profile and teeth on the Jaw designed to make it grip and pull the material through the jaw. for example, you do get for example 'bellied' jaw liners which push the choke point higher up the chamber, very useful when you have a lot of mid-range material in the feed, as more crushing takes place in the middle of the jaw chamber instead of at the toe end. A bellied liner is shaped more like a bow with the center stick out rather than flat like most jaw liners.

Picking the correct profile can be a case of trial and error, and can include having different Swing and Fixed Profile liners in the Jaw to find the sweet spot in terms of performance and wear. Have some pity on the liner suppliers, most companies will stock the top 2 liner profiles which fit 80%-90% of applications, if you require specialized liners you may have to carry the additional stock yourself and order well in advance.

One of the main reasons I find for the jaw 'bogging' (If I understand you correctly) is the nip angle. The Nip Angle is the angle of the V between the swing and fixed liner. The CSS that the jaw is set at has a great influence on the Nip Angle and performance of the Jaw.

What tends to happen is that some manufacturers try to give you a very large feed opening and claim you can close the jaw down very small. Even a well-designed Jaw that is closed past it's recommended CSS will have the same problem. The larger the nip angle, the more the crushing force is directed upwards instead of inwards. The result is that instead of squeezing the material between the two jaws, the material tends to float inside the chamber. This forces all the crushing to take place at the toe end of the liner, slows down production, increases wear significantly as the material is constantly rubbing up and down on the liners, and will most likely lead to early bearing failure in the medium term.

Having too small a nip angle will provide its own problems.

You'll find on the better jaw designed, the larger the feed opening (i.e. it accepts a larger feed size), the longer the chamber will be so that a good nip angle can be maintained.

This is one of the main reasons I try advice to always spec the Jaw to match the performance of the rest of the plant. Having an oversize jaw can be/is counterproductive to operations in so many different ways.I hope I understood your question correctly, I know the question was more about the liner design, but personally I believe the nip angle is a more common problem and has a greater effect on production.

Depending on hardness of the ore crusher designs change. Jaw is not suitable for granite type rocks. Use gyratory crushers. If jaw is used bear with the liner wear. It is normal. Or go for a higher capacity jaw crusher.

As a manganese casting engineer, I share my ideas about the wear life.

• The hardness of material which you crushed, it is the most important figure! Most of jaw plates are manufactured by high manganese, Mn14, Mn18 and Mn22 . Different material suit for different hardness!
• The microelement in jaw plate aslo effect the wear.
• The product quality. Heat treatment , successed or not? The weight and size, 100% based on drawings? Machining ?  and so on!