Selected Answers

From OM PRAKASH JAT of Galadari Engineering works on March 5, 2015:
Recycling abrasives gives irregular profile with&n ...read more Recycling abrasives gives irregular profile with  a contaminated surface, which is one of the major causes of painting failure and low production rate. One more thing is that used abrasive is flying into powdery forms during blasting and is hazardous for the blaster's health, especially for their lungs.

From Barry Barman of Barry Barman & Associates on May 6, 2010:
Whether blast cleaning takes place in the field or ...read more Whether blast cleaning takes place in the field or in a shop (with centrifugal wheel machines), recycled abrasive media becomes contaminated and breaks down in size,such that the ratio of smaller sized particles in the work mix increases, thereby reducing cleaning efficiency. This necessitates the need to pass the abrasive through equipment that adequately removes fines and debris (“cleaning the media”). In the process, new, larger-sized media should be added back to keep the work mix in the proper ratio. Failure to do so will result in poor production rates and an excessively “dirty” and undersized abrasive media that will leave the steel with a shallow profile and contaminated with the same material that was initially removed from the steel.

From AJ van Rijsbergen of solublesaltmeter.com on May 7, 2010:
Recycling abrasive is environment friendly, which ...read more Recycling abrasive is environment friendly, which is, of course, a good thing. On the technical side, blasters and coating inspectors must be aware that the contamination level of the abrasive, especially the conductivity level, will increase during each recycle step. Eventually, a high conductivity level of the abrasive can be the cause for adding soluble salts to the blasted surface, which could exceed the allowed maximum level.

From Pieter van der Poel of Danieli Far East on May 7, 2010:
Depending on the initial size and type of the abra ...read more Depending on the initial size and type of the abrasive, after proper recycling with a recycling system to remove the dust, the remaining abrasive, reduced in size, would result in more abrasive particles impacting the substrate, thereby increasing the cleaning rates. However, the finer abrasive particles will reduce the profile, so a mixture of new abrasive should be added to the recycled abrasive. Further recycling would prove counterproductive in terms of cleaning rates due to the loss of mass of the finer particles (kinetic energy).

From HK SAXENA of BREDERO SHAW on May 6, 2010:
An improper working mix after recycling will reduc ...read more An improper working mix after recycling will reduce the profile. Also, dust levels will increase due to the finer particles in the recycled abrasive.