Waterjet garnet

[gman]

I just got a new waterjet and looking for any ideas that others have on disposing the garnet. Currently we are producing about 1 ton of old garnet a week and the drums are filling up fast. I know the obvious--getting a dumpster and have it carted away--my shop is in the wonderful state of NJ and the current disposal rates are $70.00 per ton plus a $200.00 tranportation fee. It is tough enough trying to be competitive and making a profit without this extra charge.

Any ideas

[jcc3inc]

Sir,

Is there a ready-mix company near you? They might use it as an added to their concrete. How about a concrete block mfg company - could they use it in making blocks?

Is the stuff re-usable in your machine if it were dried?

Another possibility might be inclusion with hot mix asphalt; likely it would have to be dried for that application as well.

Jack C.

[gman]

I tried them all
But thanks for the ideas

[jetman]

i'm in the uk i also produce about 1 ton of garnet a week , but here it

costs me about $165 to dispose of 8 ton, if i had your sort of costs i would

be looking at recycaling as much of the garnet as i could.

[widgitmaster]

ThomasNet.com

February 23, 2001
Abrasive Waterjet Cutting May Slice the Competition
By Katrina C. Arabe
A recent development in waterjet cutting techniques has proven advantageous over competing methods. Learn how recycling expensive abrasives bolsters waterjet cutting popularity.

As a result of a recent design breakthrough, the traditionally expensive technique of abrasive waterjet cutting has been made more affordable. The innovation is a filter system that recycles the expensive cutting components, comprised mostly of garnet, for reuse after the cutting process. Abrasive waterjet cutting works by hurling waterborne pieces of garnet and other abrasives at astronomical speeds through a given material. The thousands of tiny garnet particles that erode the material are themselves further decimated through the cutting process and they are then washed away, along with the water and worn-away material, to collect in the form of sludge. This composite sludge accumulates in a tank for later disposal. In the past, the garnet debris that was held in the sludge was considered too disintegrated to be useful. With the advent of a new filter design called Waterjet Abrasive Recycling Dispense (WARD), the near-microscopic bits of garnet can be extracted from the sludge and recycled to considerable cost savings for the company.

The way the WARD system works is elementary. As the waterjet cuts the material, the resulting sludge is carried to a water tank. This sludge is then removed from the water tank by a patented nozzle and pumped to the top of the WARD unit where it passes through a series of vibrating screens. These screens wash and separate the sludge into its respective components: unusable waste and reusable abrasive agents. All abrasives larger than a predefined minute grade are then dried. These recycled bits can then be reused immediately or mixed in with a new batch of abrasives at a preset ratio. Generally, the diameter of the WARD screen is the factor that dictates the rate at which the sludge is processed for recycling. The greater the diameter of its screen, the faster the WARD can do its trick. In addition, the fact that the WARD removes the sludge from the tank itself helps in reducing both the removal cost and the downtime spent by having to stop the cutting process to clean the tank.

The time and money the WARD saves gives waterjet cutting an edge over competing cutting techniques. With other processes, such as oxyfuel, plasma and laser, the consumables are gases rather than abrasives. The gases used in these heat-cutting processes are burned off and are irretrievable. They will, therefore always be an expenditure. In addition, heat cutting has a host of disadvantages not experienced by waterjet users. For instance:


The heat-affected area created by heat cutting, must be removed or else it will become an obstacle in secondary machining.


Heat cutting also requires the creation of unsightly "start-up" holes in the material that must also be smoothed.


Further, due to the fact that the metal must remain grounded, sheets of metal cannot be stacked during heat cutting.


Also, during the plasma cutting process, one side of the cut must be left beveled. The material shorn away by beveling must often be discarded. This is an unfortunate waste of expensive materials. The thicker the material, the wider the cut and hence, the more material wasted.


Finally, the worker doing the heat cutting must wear special heat-resistant clothing, as well as a welding mask, which entails additional cost for protective clothing for the operator.

The fact that abrasive waterjet cutting is relatively free of these disadvantages, coupled with the advent of the WARD garnet recycling system, means that this traditionally expensive cutting method may soon experience a surge of popularity. Whether or not abrasive waterjet cutting will become the cross-industry standard has yet to be seen.

Source: Waterjet Abrasive Recycling Challenges Heat Cutting
Scott Deaver
Metalworking Equipment News, Feb. 1, 2001

[widgitmaster]

All though I have never used or seen a WaterJet machine, I find this to be fascinating!

I hope the article above helps!
Eric

[chipmaker1]

one division of our company recycles asphalt, concrete, etc and uses that as base rock and material for their asphalt plant; they take garnet from a local facility that has a waterjet. It does contribute to the fines in the material and they do like to keep that to a certain level, may be the reason they wouldn't take it in your area.

[2muchstuff]

Know anybody with a gravel road or wanting to build a beach.

[TopShelf]

The WARD recycler is a 33 000 USD boat anchor. Its sitting, wrapped up in plastic in the materials yard. A few hours of use lead to a few hours of maintenance. We have a 13 x 6 foot pool and a Waste Management company brings a honey wagon over and sucks it all out, nowadays. What happends to it after that is a mystery.
-Matt

[gman]

I was never considering the Ward. Our plan of attack is buying a dump trailer and look for places that can sand as clean fill.

[SuperChuck]

I'm curious, whats a ton of garnet cost in this application, whats the typical size specification? Is it actually more to dispose of it than to buy it?

Is the biggest issue the fact its contaminated with the metals? The garnet itself is an aluminosilicate, so its fairly chemically inert, heat stable and should have a low thermal expansion. You may also look into applications where the material is fired, refractory bricks, etc. although the metal contamination may cause problems.

Does the sludge oxidize and turn red(rusting) over time? If so, any type of park sandbox, playground fill donation would be out of the question, plus the fineness would not be suitable anyhow.

Aside from the other applications mentioned(fillers for concrete, cinder block, asphalt), I can only think of finding out what the local coal fired utilities do to their fly ash. Maybe they have a landfill thats accepts inert materials versus household wastes. Considering the mercury, trace NORM materials and other heavy metals in fly ash, the garnet is nothing.

SC

[Sir_Luck]

Our local Coal fired plant sends the fly ash through a chute directly to a dry wall plant on the same grounds.