Here’s a series of short, easy-to-answer questions that make resolving your kind of situation a straight forward deal. They’re as follows:

1. What is the largest size material going into the crusher? (the size by 2 dimensions, i.e. 4 inches x 3 inches)

2. What size range (again, by 2 dimensions) does 50 percent of the gross feed material fall into?

3. What is the actual physical discharge setting of the crushers?

The two 7-foot standard cones in normal crushing conditions may be run at a 1.500 inch c.s.s. and would send the S.H. cones a moderate percentage of 3 inch by 2 inch material in an open circuit. The 50 percent size range would be something like 1.500 inches by .750 inch material and if in a closed circuit, a finer feed blend would be prevalent.

The liners you are using sound to be either be too fine for the job, or are losing their available feed opening thru normal wear. With the 30 day liner changes that you’re experiencing, that loss of feed opening becomes apparent within the first 25 percent of the liners’ life. The seeming high wear rate near the top of the liner set you describe begins near that same time and progressively diminishes gross output rate.

This is the most common phenomena present in cone liners and the subject we deal with most often when providing our Hi-Pro / H-D liner profiles. The object is to provide liner sets that will accept large feed size of a given blend through total expenditure of the liners, while still providing the percentage of sized discharge material required. Simply applying coarser liners doesn’t fix the condition.

This increasing of the feed opening is often misunderstood as an attempt to allow for larger reduction ratios. That’s not the case at all -- we just don’t put wear metal where it’s not needed.

That’s the rate of wear you’re seeing in the liners you use now. In your case, we’d likely provide a fine to medium liner set with an increased feed opening. These are the kind of liners that allow the top sized feed material to be accepted by the liners on the closed side (or at least for within 15 degrees of the closed side at the top circumference of the crusher.) We’d need to know what sizing requirements you have for these crushers in order to offer a specific liner set for the need.

Your question is common to what we deal with daily for most models of crushers. For example, for 7-foot Symons crushers in particular, we’ve developed several options in degrees of fine verses feed opening and thickness. Your situation is common and reasonably easy to deal with.

I am afraid we don’t have real good news in way of a cure for your situation – although, we’ve been exposed to the major aspects of your difficult situation. Let’s begin with the use of impact type crushers in high silica reduction applications. We were exposed to one of our large customer’s high volume use of wear steel in the production of shaped and colored granules. The product they make requires several stages of conventional crushing. In most cases 5 stages of reduction are required to take quarried material to finished sieve sized finished product. They experimented extensively with impact type crushers while trying to reduce stages of operation. The conclusion was drawn by a pretty high powered group -- that if the silica content was over .4 in the mineral being reduced, you couldn’t afford to do the crushing with impacter type crushers. 50# hammer like parts wouldn’t last 8 hrs. So the range of service life you describe is similar. The tests conducted were funded by the manufacturer of the crushers and fact was they left the project with their tails between their legs. We learned a lot from following that one. What we learned was that even with high hardness (700 bh) irons, suitable wear life couldn’t be obtained with that type of machine, in high silica applications. Your situation is worse than what I just described with quartz being all silica. This information was compiled nearly 25 years ago and that material is still being mined and crushed most successfully with a conventional 5 stage crushing operation. That begins in the quarry with the following crushing machines -- a primary gyratory, followed by a coarse crushing cone, with 2 more increasingly fine crushing cone crushers w/ the finished shaped product made in roll crushers. The second part of your dilemma being the magnetic removal of the spalled wear steel contaminants in the material -- we’ve run into that one, like yourselves, with glass sand producers. We’ve made conventional crusher wear parts from high hardness grades of carbon steel, as opposed to conventionally applied manganese steel, so as to allow similar magnetic separators to function the same way you have to -- to keep the oxidized material from discoloring the glass. Our findings in that arena, have been that when applying the high hardness carbon steels (up to 600 bh, most commonly 400 bh materials), the service life with the same kind of crusher, is typically one half of what like sizing of low silica range materials is with manganese steel. However, manganese steel applied to very high silica minerals is half of that of the carbon steels. Follow that statement carefully -- very high silica mineral crushing with manganese = very poor wear results. Very high silica mineral crushing with high hardness carbon steels improve wear life by a 2 factor, although are still a very poor half of service life manganese steel provides in lower silica bearing minerals. All is being compared in the same kind of crushing machinery with the same sizing requirements. The bottom line is, you have a bad set of conditions going for you and it’s possible the type of crushing machines you have, may not be the best choice for the material your reducing. High speed crushers will make the magnetic separators less effective as well. Your costs have to be at minimum triple that of conventional aggregate crushing. That’s the best we can come up with from here -- you might ask yourself the question whether or not you have the best equipment for the job.

We don’t claim to be real knowledgeable on this subject and have had only limited involvement in parts for this application. You’ll likely find that the way they go about reduction of coal differs considerably from aggregate producing. The sizing requirement you’ve noted, is over an 18:1 ratio. Primary jaw & gyratory crushers are effective only to half that kind of reduction, & wouldn’t come near getting down to the finish size product required. We’ve made parts for some multiple stage varying toothed roll crushers that are sometimes used in the crushing of coal. They’re multi-staged, to the point of 3 or more levels of coarseness, within the same machine, to allow getting to the sizing you’ve noted. They’re certainly not oriented towards wear life efficiency. Some of the ones we’ve provided allowed only a 10 to 15% wear material ratio to the casting carcass. They are very expensive pieces of equipment, to own and operate. A couple OEM crusher manufacturer names you might look into would be Krupp-Polysius and McLanahann. We’ve not had enough to do with these kinds of machines to be of much detailed help. Good luck in your search.

I’m not familiar with that particular manufacturer name, or model of primary gyratory crusher. It’s possible this may be a more commonly known model, manufactured under license by the name you’ve noted.

We have a comprehensive history of similar machines, stretching over 70 years. Resurrecting and reconditioning these old substantial design machines is becoming a more common affair and it’s not out of the realm economically to put considerable resources into reconstructing these old machines.

We’ve been involved in providing the wear parts for several similar projects. With crushers of this size, it would be within reason to see pattern costs in excess of $70k, with the necessary wear parts including the mantle(s) and concave segments costing another $90k. The other miscellaneous wear-out parts such as the head nut, torch ring, spider covers, arm guards, etc., could easily total another $50 to $100k. This could still be viable, when you consider that the cost of new similar sized machines exceeds $2.5 m.

Collecting the information required to accomplish positive results would be a trying venture in itself. In regard to what we could supply to aid in your project, we’d either have to identify your crusher by another more commonly known manufacturer and compare dimensional information to what we may already have that suits your machine – or, we’d need complete and accurate field measurements with sketch information that would allow manufacture of the needed components.

The fitting dimension information could be taken from existing partially expended parts. This would best be done by an engineering firm hired to do that kind of work. However, I don’t have knowledge of firms in your part of the world that are capable of that kind of work, or the complicated mechanical and machine work necessary for this kind of reconstruction. There are several companies in the U.S. that specialize in this kind of work, although transportation would be too much of an issue to consider anything like that.

There’s likely someone closer that would be likewise as proficient. You may want to start out with a couple of the crusher manufacturers located in Europe, such as Metso Minerals (Finland), or Sandvik Rock Processing (Sweden). They may be able to direct you to someone experienced in that kind of work. If forwarded detailed enough dimensional information on the wear parts, Columbia Steel could be of service in that part of the project. Good luck in this worthwhile sounding project.

Leave the eccentric at the 1.000-inch mark for a starting point, but you’ll want to try various lengths and positions of toggling points. That’s how you’ll achieve the action of the machine.

For example, if you want to close this machine down to a 1.000-inch discharge setting, you’ll want it to toggle in such a manner as to provide an open position setting of 2.000 inches. Most crushers of this feed opening and approximate width have jaws slightly over 24.000 inches long. Toggle the machine in such a manner that the discharge match points align somewhere between the open and closed side settings, perpendicular to the back of the moving jaw. If you’re building something from scratch, you’ll have a little trial and error in your preliminary modeling.