MechTech May 2016 Final

Mechanical Technology — May 2016

⎪

Materials handling and minerals processing

⎪

Pipe launders

make their way to chrome

ultotec’s pipe launders are well

known in the mineral sands and

iron-ore mining industries. The

polyvinyl chloride pipe launders have

proved their worth in these arduous ap-

plications for many years, significantly

outperforming their steel rubber-lined

counterparts. Now, chrome producers are

taking note of their benefits.

This includes Nor tham Chrome

Producers, the first chrome miner to put

Multotec’s pipe launders to the test, and

Multotec’s Graeme Smith reports that

the company will shortly be supplying an

additional 400 running metres to another

undisclosed chrome producer.

The pipe launders were supplied as

part of a spiral retrofit project at Northam

Chrome Producers’ recovery plant. A total

of 72 of Multotec’s HX5 and HX3 spirals

were designed, manufactured and installed,

boosting the plant’s recoveries by as much

as 6.0%.

The plant was using conventional steel

rubber-lined pipe launders that had been

designed for the previously installed spirals

that were also due for replacement.

Smith says that Multotec’s Technology

Division discussed the many advantages

offered by its pipe launders with the plant’s

management team. “We detailed the pro-

posed layout of the launder solutions, and

the team really liked our idea of ensuring

a more durable and tidier installation that

would also be safer and easier to maintain

over time,” says Smith.

One of the biggest benefits offered by the

company’s pipe launders is their durability.

Smith says some of the company’s instal-

lations in the mineral sands production

environment have lasted for up to nine years

in highly corrosive coastal environments.

What is more, they are easy to maintain.

Their design incorporates a replaceable

polyurethane boot inside the pipe that

endures wear and

protects the inside of

the pipe.

“In arduous ap-

plications, such as

those found in min-

eral sands and iron

ore mining, the boots

would have to be re-

placed about every

two to three years,” he

says, adding that the

boot can be replaced

within five minutes.

Manufactured from a

much lighter material

than steel and having

a smaller outside diameter, Multotec pipe

launders are easier to handle and can be

installed by two men without the need for

any lifting or hanging equipment.

The launder pipes supplied to chrome

producers have an outside diameter of 200,

255 and 400 mm. Every pipe launder,

installed from the collection point leading

down to the sump, had to be specially

designed and manufactured to fit into the

existing footprint of the plant.

It may just be that more chrome miners

will come to experience and appreciate the

benefits of a better pipe launder system,

thanks to Multotec.

Two Conturbex centrifuge installations dewatering glaubersalt and mixed salts produced using a ZLD process.

The cleaner concentrate, rougher concentrate and tail pipe launder

arrangement, together with Multotec distributors.

Siebtechnik Conturbex centrifuge is an

important feature, which enables inde-

pendent adjustment of the scroll and

drum speed. This allows adjustment

where extreme process conditions exist

and this flexibility enables performance

to be optimised.

The centrifuge is engineered in such

a manner so as to enable easy mainte-

nance and one of the features relevant

to this is the single bearing overhang

design, which allows easy access to the

internal rotating components. This saves

time, leading to greater cost effectiveness

during planned maintenance activities.

Another important time saving feature

is that cleaning nozzles, strategically

positioned within the machine, facilitate

cleaning-in-place (CIP) during scheduled

maintenance shutdowns.

Pointing to applications where

Conturbex centrifuges are operating

successfully, du Plessis says that in the

petrochemical sector these centrifuges

replaced pusher centrifuges as part of

a de-bottle necking project with the

added benefit of less frequent washing

requirements. Also in the petrochemical

industry, Conturbex centrifuges are used

to produce a sodium sulphate by-product

from a sulphur effluent stream.

Du Plessis says that there are defi-

nitely applications where the features of

pusher centrifuges will outweigh those

of the Conturbex centrifuge, however

the ZLD process is not one of these.

“We manufacture all types of centrifuges,

including pusher centrifuges, and will

recommend the correct type of centri-

fuge for the application at hand. Pusher

centrifuges are suitable for applications

where the need for crystalline purification

is essential.”

Conturbex centrifuges are also used

for water treatment and de-watering of

mixed salts, including sodium sulphate in

a colliery plant, and in a crystalliser plant

de-watering mixed salts at a platinum

operation.