The effective dewatering of ultra-fine materials has posed an ongoing challenge for a number of industries. Until now, the use of flocculant was required to ensure sufficient solids retention and good filtrate quality in cases where a slurry feed’s particle size distribution contained more than 30% of particles below 10 µm.

ZebraTube recognised the need for a dewatering bag that would retain ultra-fines without the additional operating and capital cost-implications associated with the addition of flocculation and developed an innovative new product to address this need.

“We are happy to announce that we have developed a product that achieves the dewatering of ultra-fines efficiently whilst producing clear filtrate without the use of flocculants,” states ZebraTube GM, Carien Spagnuolo.

The company has developed a patent-pending composite geotextile that allows for the cost-effective and efficient retention of ultra-fines.

During the product development phase, trial work was conducted on the lined bags for a client who produces an ultra-fine slurry consisting of calcium and sodium carbonate. The particle size distribution of the slurry showed that 90% of the distribution reported a particle size of less than 40 µm and 10% of the distribution reported a particle size of less than 5.6 µm.

“The composite geotextile-lined bags can be pumped at a high flow rate and still produce great filtrate quality. During the trials the total suspended solids in the feed was reduced from 20 000 mg per litre to less than 10 mg per litre in the filtrate in 10 minutes,” explaines ZebraTube sales engineer Tshepang Dolamo. The company further emphasises that the small-scale bags are easy to handle and are designed with loops that can be used for lifting when the bags are fully loaded and can also be easily moved using a forklift.

“We are now looking at manufacturing our tubular bags using this innovative composite geotextile, to address the needs of our customers who require the dewatering of larger volumes of ultra-fine slurries,” says Spagnuolo.

The bags can be used for a wide range of applications and the aim is to address the increasing need for flexible and cost-effective dewatering of ultra-fines in various industries.

Founded in 2016, ZebraTube has its origins in the manufacturing of geotextile backfill bags for some of the deepest mines in the world. The company has over 20 years’ experience in retaining solids and percolating liquids with the use of woven geotextile bags. ZebraTube’s geotextile dewatering bags are proudly designed and manufactured in South Africa.