Phorphorous Materials

The material inside CRT tubes is not really phosphorous. It is a man made power that glows when excited to a higher energy state. There are three chemically different powders that each have specific properties. One powder glows red, another glows blue, and another glows green. They are basically the same powder that is used in fluorescent lamps.

Once those powders are contaminated they do not perform as well as when they are fresh and new. Consequently, purity is a major issue. And separating the powers will be a little like separating salt and sugar after they have been mixed together.

However, if you find such a process that works then you will be very wealthy and you will want to sell your process to all of the major lamp-makers in the world because they have been trying to figure this out for decades. Most of the newer fluorescent lamps have various mixtures of three or more components (red, blue, green, yellow, etc.) to achieve the desired color. The purity controls how much light the bulb will yield and adding more powder simply makes the coating thicker. Before long that extra material starts blocking some of the light. So purity and layer thickness becomes a major performance factor so quickly that nobody to date really wants to use recycled powders.

Hi,

separating the different "phosphors" is ordinary chemistry in rare earth materials, more difficult than separating largely differing elements but still a known process.

There is up to now no established process but some people are aware of its necessity.

There are some research institutes working on leaching with acids.

I would try with another approach but would not discuss this in the public.

RHABE

What we have inside CRT is Red, Green and blue phosphor. The different color emitter has different dopant in phosphor. Any process of recovery if mixes red with the blue or green and view versa will make entire batch of phosphor bad.

I have not looked is there any difference of density between these particles.

Chances are no but if will not give up so easily. Look the way to differentiate physical properties so you can take advantage of this

Hi,

sorting by density is not feasible as the particles will have different sizes so sedimentation will give only a very coarse purification.

You have to go to the complicated chemistry of these rare earth elements, change the molecules, use different solubility and absorption characteristics including electrochemistry.

RHABE

You may be correct density will be tough and non viable option since these rare earth is as minor and change is not enough to perform it.

I was involved in the display screen but never paid any attention to it since we took care up front of collecting green, blue and red at different step of lay down and had no issue.

If this is my project I will look for feasibility of recovering rare earth and getting the purification technology of posphour and then some one else make green, blue and red out of it. This will be true close loop manufacturing and nothing is waste