I'll definately agree with you on the build of the machines very impressive and well thought out , I guess it all comes down to the final application of the crusher and if it's suitable for the task . I,m researching as much as possible the best machine to process building rubble and reinforced concrete , most guys that i talk to swear by a jaw crusher because of it's capabilities of handling a reasonable amount of reinforcing mesh through the machine but but the downside is the requirement of secondry crushing and screening especially if you require 1" minus final product .The Impact crusher namely the Rockster claims that it can crush and screen down to 1" minus in one pass , but i believe the pre preparation,removing most if not all the reinforcing
would slow the whole process greatly . Then last but not least is having a portable self contained crusher in a reasonable weight range that won't require a freight train to cart it about .I'm going to quit on that note ( giving myself a headache thinking through all this stuff )Cheers Shayne
Almost all demo recyclers lose most of their profitability in the pretreatment process. Usually I find by the time they have the feedstock down to a size and shape suitable for crushing, its small enough already and hardly needs crushing! The key to making money from this must be in the least pretreatment possible, which all but rules out a jaw. The need for the concrete to turn almost 90 degrees to fall into a jaw from the feeder is a problem that is redoubled when the rebar has to also turn on the way out without ripping the belt.
I used to run two Nordberg City Crushers, model C10/07 Horizontal shaft impactors. They were able to accept comparatively long lengths of rebar with no issues. The feedstock needed minimal preparation and as long as the slabs were less than 700mm (28") wide they could be up to 40-50" long with rebar or mesh inside. These models discharged onto a steel vibrating feeder which caught and turned the steel before it reached the discharge conveyor. Wear was an issue, we could use special hammers we had made which would do 50,000 tonnes but had to be careful of any "hard" tramp iron getting in there or we thought the hammers would break. We never broke any so maybe it wasn't a problem.
Initially we used the Metso stock hammers and they were doing about 10,000 tonnes. Dust was our biggest problem, of course we could spray but that causes problems of its own.
My first choice for demo though would be one of the Japanese roll crushers. We've had three of these, two kobelco KMC300R and one Hitachi HR1000 and they are very hard to beat for every reason. No dust, quiet, fuel efficient, endless production, huge feed slabs accepted up to 2m (80") square can be eaten without pretreatment whether full of mesh or rebar. The smaller HR1000 (20 tonnes) can deal with a 2.1m (7') long piece of mangled rebar no problem whatsoever and the Kobelcos even longer. There is a 48" drop from the crusher outlet to the top of the conveyor belt is the reason. The Kobelcos roll along at an easy 90-100tph and the Hitachis 60-70tph at 1 1/2" product size. Feed that through a screener set in closed circuit at 1" and you'd have exaclty what you wanted and not too many "fines"
I have one of the kobelcos available in Western Australia right now as a matter of fact. Gordon
