Hi,

An enclosed troughed belt alone is out of the question. Your duty is to self (operatives): then the neighbours & only finally the environment.

Enclosing a troughed belt also encloses the staff. You will have to provide safe exits dispersed along the 20km. These might provide exit of your radioactive toxin near the roads & waterways mentioned. You'll need airlocks (double door sets) at the exits.

Plonking sheet metal covers over a belt in a covered gallery still exposes workers to hazard. Your minimum safe kit would be a multi flight pipe belt inside a gallery. Expense is seriously secondary; even if it comes second at all. Whatever dust containment you need at transfer points the gallery ventilation is also going to be quite daunting.

I know South Africa & I remember when ESCOM used to mix isotopes in the coal at power stations & then chase the fumes with a geiger counter carried in a light aeroplane..TRUE....to examine pollution dispersion. Its not that long ago either! But times are supposed to have changed.

As soon as radiation is mentioned your Erin Brockovitches will be all over you like a rash.

Consider that the longer the conveyor stays up the more hazardous it becomes when you have to dispose of it. You're talking about shifting 2,000 plus tpd for 20km across the veld.

You could have an underground route if the rivers are known beasts. Can South Africans work underground...is a 50kg chicken fat?

You're being creditably straightforward with the forum & no doubt your openness would be appreciated by the local authority. Why not see what they will allow. Find out now rather than later. Best of luck. ■

CobusT,

There is a trough belt alternative to the pipe conveyor that will not have the wind erosion issues. The product will not be liberated into the atmosphere. It can transport very fine material. There will be no spillage on the return strand that does happen with pipe conveyors.

Take care with the pipe conveyor. Most often the return side belt is oriented with the seam down. Product will likely spill or escape from the seam oriented down. The seam is turned down due to the belt's construction. Fabric and steel construction have a bias between the lower cover and upper cover. The lower cover has a wider transverse reinforcement to inhibit the edges from collapsing with the seam up.

Pipe conveyors have the corkscrew problem that designers ignore due to the complexity in predicting its existence and magnitude. We have produced analytic means to demonstrate how, where and by how much corkscrewing will occur.

If you have further interest, please contact the undersigned. ■

Does one system have an advantage over the other with regard to radiation? I'm not aware that rubber serves as a radiation seal.

Since two-way conveying (conveying in both directions) is required either system must include belt turnovers so that the carrying side of the belt will also be up on the return. In the case of the pipe conveyor this will also put the pipe seam on top.

In this light it is doubtful that the pipe conveyor system will be competitive with a troughed belt system.

I bite my lip as I say this but what about the underground pneumatically propelled encapsulated system that Mr. Izaharas is always promoting?

Joe Dos Santos ■

May your lips bleed Joe.

Most belt mfgr's and designers do not want to apply turnovers on pipe conveyors due to the pipe belt's construction. I said this on a prior response in this thread.

Pipe belt construction typically has a set of fabric reinforcement layers with varying lengths of transverse fabric width. This is configured to apply a defined stiffness to manage the pipe shape over its life. This acts like a spring to force the belt to pressure the containment idler configuration.

The pipe tends to become more supple with use and thereby losing its spring open effect. The high level of use can cause the outer edges to collapse downward toward the pipe's center. This causes other problems. ■

Dear Sir

This is clearly a project where a pipe conveyor is a sound option.

It will enclose the product both for security and from the elements.

It will eliminate many potential transfer points.

However when installed on the ground without walkway it will be more costly generally but this should be analised case by case.

Regarding return run when set up correctly there is minimal spillage on return strand and when set up for return conveying the joint or seam is at the top like it is on the top carrying side. This is aheived by belt turnovers.

Regarding 20 kM this is very large project and depending on available belts and the contours may have to be in 2 or 3 flights.

To be sure about the complete comparison a full analysis should be done.

Paul Holt

AMCO Construction Ltd (Dosco Overseas Eng Ltd) ■

A real option is the ROPECON system from Doppelmayr - will handle the material and length- ■

Ropecon for radioactive dust...up in the sky.

It must be South Africa. Give over! ■

Actually the "heavy minerals" in discussion is the beach sand from the dunes prior to any treatment. The sand is transported to the separation plant and the non heavy minerals returned to the site - up to 96% returned.

A recent detailed study including an independent environmental study with full public participation showed that the handling system that is being queried does not handle any radioactive product but only handles the sand. The Ropecon system is ideal for the sand delivery and return system using the bottom strand.

The portion that stays at the plant for further treatment is the 4% final product mix and even then only some deposits may have some radioactivity in the concentrated zircon portion. This would be seperately contained and sold. The majority of the 4% after the smelting and crushing process that follows is a fine grained material which has no "contamination" at all but needs an enclosed controlled handling system.

There are in fact at least four operations doing this type of work including Australia, and Southern Africa

without any problem.

As a handling system, the Ropecon system is proven in an operation handling and retaining wood chips with a full cover - and tested up to 120 km per hour wind. - a European installation. ■

I must have read the thread starter wrong then!

The portion that stays at the plant, the radioactive bit,: how did it get there? Is your process magical as well?

It's just a meneer of change. ■

The no-contaminant revelation changes everything and this thread reduces to a cost comparison of various overland conveying methods.

Though the Ropecon is unique, considering both the support system and the conveyor that it carries, I beleive that the support system is as applicable to a conventional troughed belt system.

Joe Dos Santos ■

William,

you want to use your 20m system on a 20 000m link?

Are you sure?

Darrell ■