Usually, a given manganese wear parts supplier offers two grades of manganese; a regular grade which is around 12% and a premium grade which is around 18%-24%. To increase liner life with the premium grade one has to be crushing a higher compressive strength stone, granite would certainly fall into this category. I have seen that with customers using our premium grade manganese and crushing granite, their liner life has increase by 15%. This does not say that your liners will attain this added service life, but, you should experience some increased service life.

To answer your next question regarding cracking, one must first understand why the liners are lasting longer. Due to the nature of the premium grade manganese, the crushing surface will work harden to a greater extent. Anytime this occurs, you run the risk of cracks forming due to fatigue. We have found that the amount of trace elements help to limit this from happening, thus allows a set of liners to run full term without cracks forming.

The typical manganese steel cone liner is made from ASTM A128 grade B-2. This covers a range of alloys that fit within the following composition range: 1.05-1.20% Carbon, 11.5-14.0% Manganese. These alloys also have some silicon and tramp elements with the remainder being approximately 85% elemental iron. Chromium, molybdenum and nickel can also be added to these steels for various reasons. Columbia Steel Casting Co., Inc. and other producers also produce liners from various premium grades of manganese steel that contain additional carbon, manganese and other alloy elements to improve the service life of the casting.

Answered by: David Havel, P.E., Chief Metallurgist

Blasting and explosives are outside my expertise. Try contacting an explosives company like Dyno Nobel Inc. - www.dynonobel.com.

Regarding directories of Quarries in North America, try these for US quarries:
* North American Aggregate Industry Directory - www.rockproducts.com
* USGS Aggregates Industry Atlas - www.aggman.com/atlas
* USGS directories and atlas from the source - http://minerals.usgs.gov/minerals/pubs/commodity/stone_crushed/

For Canada, try this government site: http://mmsd.mms.nrcan.gc.ca/stat-stat/mine-mine/index-eng.aspx

In any given single toggle jaw crusher there are typically two toggle seats, a frame and a pitman side, and one toggle plate. Although there are many factors in just how long a set of seats and plate will last, I have typically seen them average from three to eighteen months depending on the severity of the application.

Typically the designation or size of jaw is called out by it top opening. The first dimension is usually the distance between the stationary and movable jaws and the second dimension is the roughly the distance between the cheek plates -- thus the “usable opening”.

I agree with you when you say that the jaw size”36 x 38” is a bit odd. I checked back into the records at my disposal and found that most of the companies that manufacture jaws have a 36 x 42 or a 36x 48. This seems to be the norm for a 36” opening between the stationary & movable jaws. That’s not to say there has not been one made with the dimensions you have called out.

I’m not sure just what you mean by feasibility. Any given crusher manufacturer can, and at times has made jaw sizes out of this normal range of widths. What initially comes to mind are the jaws which have been produced to accommodate the recycling industry. In some cases there have been width increases to allow longer “slabs” of material to readily enter the chamber without bridging & plugging up the crusher.

If I were to have the manufacturer of the jaws you are reviewing, I would be happy to look into it further. If you choose, you can contact me directly at steve_dz@columbiasteel.com.