A photo of the RockLabs® hydraulic crusher/splitter with the vinyl flaps down. The hydraulic pump is the yellow thing on the left. The on-off switch is on the right side of the pump, and up-down lever is located on the top of the pump behind the handle.

Prelude

To use this crusher you need samples of appropriate size, say at least 5 mm across. Smaller samples are more easily crushed in a Plattner mortar, usually kept with the mineralogy teaching equipment and in the X-ray diffraction lab. If your samples are bigger than 100 mm across, they will not fit between the crushing faces. You may also have to break off weathered areas, joints, veins, or other parts you do not want in your final crushed sample. Find a place to break your big samples into smaller (50 mm) samples using a hammer or the hydraulic splitter wedges. Use a wood stump to put the rocks on before you break them.


You will need the a stump and a hammer, perhaps a big hammer, perhaps even a sledge hammer. You also MUST use safety equipment, particularly goggles (eyeglasses are not enough). Hearing protection is also wise.


After you finish breaking your rocks into suitable size pieces, you MUST clean up after yourself.

Overview

The RockLabs® crusher and splitter is basically an hydraulic powered ram with two pairs of tungsten carbide working tools. The hydraulic ram has a maximum force of ~29 tons, though much less is actually needed to crush any rock that can fit. The flat pair of tools have upper and lower tungsten carbide plates for rock crushing, designed for rocks up to 5 cm across. The knife edge pair is used to split cores or to break large rock. The splitter contains top and bottom triangular tungsten carbide bars. The two different pairs of tools swing in and out of position. Spring-loaded pins hold them into position. The resulting small rock fragments and powder can later be further processed and analyzed.


The flat crusher tools are rotated and locked into place (the splitter tools have been rotated around behind).


The splitter tools have here been rotated and locked into place (the crusher tools have been rotated off to the sides). If the ram seems to move slowly when you run the pump, or the ram seems to have a hard time moving up and down, spray or wipe a little WD40 onto the guide rods.

Operation

The first step in operating the srusher/splitter is safety. Safety goggles and hearing protection should be worn at all times when crushing or breaking rocks. The vinyl flaps that surround the instrument must be down at all times, but these should not be relied upon to stop all flying rock fragments. Next plug the pump into a suitable outlet. The pump is operated in the same way for both the crusher and splitter. A lever on top of the pump behind the handle has three positions: to the right, the ram will go up; to the left, the ram will go down to crush or split your sample; the middle is neutral and the ram will not move and the ram piston is depressurized. Regardless of the lever position, the pump needs to be turned on. This can be done with a manual switch in the right side of the pump, or using the foot-operated switch.

The electric pump that runs the ram. The lever is on the top, toward the back, and the manual on/off switch is on the right side.

A photo of the lever used to control the vertical movement of both the bars and plates. The lever is currently in the up or ascending position. Always stop the pump before the reaches the top position. This puts unnecessary stress on the hydraulic system and ram supports. If it does reach the top, move the lever to the neutral position to cut the pressure. Never apply more pressure than you need to crush the rocks, because that just compresses the powder into lumps. Never let the tool faces touch each other, they are brittle ceramics and can easily be broken.


A photo of the foot operated switch used to run the electric pump. Your foot goes in the big side to turn the pump on and off. The lever on the pump controls the direction the ram moves.

Cleaning

Before crushing anything the samples have to be free of weathered parts, veins, altered joints, and other potential contaminating factors. This kind of sample cleaning is usually done with a hammer or with the hydraulic splitter tools. Samples coming in from the field may have to be cleaned and rinsed with deionized water, then air dried, to remove contaminating dust and organisms.

 

Cleaning the crusher itself is perhaps the most important aspect of using this device. If you don't clean it, contamination between samples will result in inaccurate, possibly meaningless data. Clean the device before crushing anything. After crushing one sample, the sample fragments are collected into a plastic bag or other container. Vacuum up loose chips and dust, then wipe down the crushing faces and surrounding area with a damp sponge.


A plastic sample bag used to collect the rock powder and fragments after being crushed by the tungsten carbide plates. You may want to use a sieve to hold back bigger bits for recrushing.


After many hours of crushing you will look longingly at the exit door.

 

The above information was provided with the aid of the RockLabs© Laboratory Hydraulic Crusher/Breaker Instruction Manual. This web page was orignally prepared by Mike Nigro.