THE NEW KEENE Produc t ROCK CRUSHERS Report AND COMBINATION By AU Testing Laboratories ROLLER MILL Base Mount Trailer Mounted Electric Driven dered a competitive price on the mar- testing site because it contained an Keene Engineering has brought into ket today. THE COST IS LESS THAN abundance of fractured quartz rock view, a new ROCK CRUSHER that HALF. containing gold and silver. The rock has brought the mining industry to its When AU Testing Laboratories was also extremely harder than com- feet. A new combination rock crusher first agreed to make an evaluation on mon type ore of this nature and and roller mill that has the capacity of this product, we were needless to say should provide a good test for any crushing a four by six rock into "ultra skeptical about the manufacturer's type crushing equipment. fine powder," in one single, quick and claims, but were again impressed Although the unit weighed over efficient operation. They have com- with the performance of this beauty. 700 pounds it was surprisingly easy bined two separate processes of rock We learned that Keene had been in to tote around. We moved many crushing into a single machine. the process of engineering and test- times to different locations on the The first stage is a jaw crusher ing this unit for over 10 years and this mine site with relative ease. We that crushes aggregate to one quarter unit has evolved from some twenty understood that this machine could of an inch, that can be adjustable to previous prototypes. be provided on either a permanent larger or smaller size and the second We loaded the unit with its base or trailer mounted. We chose stage is an adjustable roller mill that portable trailer on the back of our pick the trailer mounted model, as it more further reduces the grind to a fine up and headed for an old mining area adequately fit our needs for portabili- powder. that had been abandoned several ty. No, this unit doesn't cost ten years ago due to low grade ore. We Before we started our test run thousand dollars, that might be consi- figured that this area would be a good we noted that the crusher was really 34 equipped with beefy appearing struc- tique. We did make a couple of sug- ture and heavy duty bearings, much gestions to the Keene’s regarding larger than we have seen on similar Chain Tensioner. It was bothersome size crushers. making periodic adjustments every The engine was the new eleven few hours. We recommended an horse power. Honda industrial alu- automatic tensioning device that minum block with steel sleeve would maintain proper tension. We engine. We noted that the feed hop- also suggested that they should con- per was a safe arrangement to pre- sider a device that would divert the vent rocks from being thrown back at crushed aggregate away from under the operator while running and the the machine in order to make it con- belt shrouds were well designed for venient to remove the material. safety and could meet any mining Keene was very receptive to our sug- Roller Mill and Heavy Structure safety requirements. The crushing gestions and we understand that The rollers are fabricated with a 4340 jaws of this baby were heavy grade these changes have already been put alloy steel and treated to a Rockwell hardened steel and the roller mills 50 Hardness, that offers an incredibly were heavy duty and of the type that long roller life. We experienced virtu- we have seen on much larger units. ally no wear during the several days We threw everything we could we worked this unit. find at this baby for over an hour, just We again, have to credit the engineers at Keene with another superbly designed piece of equip- ment and another first in this industry. We also have to mention this smaller rock crusher that is designed Reliable 11 HP Honda Engine primarily as a pilot mill and unlike the RC46 is not a production machine. into production. Material is fed into the hopper We questioned the absence of and drops into the center of a high vertical grooves on the jaws that we speed tube. The centrifugal force have experienced with other brands. throws rock into a hardened steel Keene said the sole purpose of the impact wall at speeds in excess of grooves were to relieve stress in 400 MPH. All material passes into a cases where inadequate bearing size five gallon bucket sealed chamber Heavy Duty Bearings It is a light weight and very eco- were present. He also replied that nomical rock crusher for the prospec- to see what it would do in a given such grooves could slow down pro- tor, weighing only 85 lbs. It is mount- period of time. We were amazed at duction capabilities and their flat ed to a vertical 5 hp Briggs and the rate it digested material. plates provided more usable crushing Stratton and will handle rock of one We weighed the powder that we area and surface, thus making the inch in size and can produce up to had processed in that one hour peri- jaw speed faster and more efficient. 4000 lbs of grind in just one hour in a od and it was over “seventeen hun- Although we agree that the single pass dred pounds." Although the manu- RC46 Rock Crusher is more efficient, facturer had rated the machine at a faster, more portable than others we slightly higher capacity, the rock was have used, the most important factor extremely hard, we again were that is worthy of mention, is impressed with this performance. "DURABILITY." Like so many other machines on the The RC46 has the components market that we have tested, it was of jaw crushers, at twice its size," by truly gratifying to find that the market comparison. Its 21 inch machine actually met the manufactur- eccentric shaft is "one piece", provid- er's ratings. ing extra strength to hold the bearings We continued to work the and fly wheels from any possible mis- machine almost non stop for several alignment. The bearings are the days, examining the unit for any largest we have ever seen on this weakness in the bearings and any size crusher and are taper roller bear- excessive play due to wear and tear ing that require minimum mainte- and found very little that we could cri- nance and offer extremely long life. RC-1 G FORCE ROCK CRUSHER 35.