CDE has helped SOMEVAM, a subsidiary of the Sebri group, diversify into a new market by providing a tailor-made wet processing solution that eliminated contaminants and increased the quality of its end products.

SOMEVAM has operated sand quarries in Oueslatia, Tunisia, serving the national construction market since 2001.

Following testing of material, SOMEVAM saw the opportunity to diversify into the glass industry in North Africa and Europe, and produce a range of supplementary products, including industrial sand and silica flour. The company also wanted to produce a 30-150 micron fraction that would make its offer unique in the region.

SOMEVAM sought an effective wet processing solution that would eliminate contaminants and offer variable cut points to increase the quality and commercial value of the end products, CDE said.

Each day, SOMEVAM extracts 3,000 t of sand. To handle such quantities efficiently while also adhering to stringent quality standards requires the most advanced, durable and sustainable processing equipment, the company added.

“Together, the Tunisian company and CDE have developed a tailor-made wet processing solution to support SOMEVAM to achieve its commercial growth aspirations,” CDE said.

The design process, underpinned by CDE’s co-creation approach, allowed CDE engineers to work directly with the SOMEVAM team to develop a modular wet processing installation suited to the feed material (including a silica content of 99%) and the company’s production targets.

Habib Sebri, CEO of SOMEVAM, explained: “Before we got into glass sand, we operated the Oueslatia site for the production of building materials. However, it was clear that the material on site presented an interesting commercial opportunity in the field of silica for flat glass applications such as windows, mirrors and flat glazing.”

Sebri says it was important to invest in the right sand treatment equipment to guarantee the success of the project.

“After exhaustive research of the various options at our disposal, we chose a modular wet processing solution from CDE. The expertise of the company’s engineers and sales team, its investment in innovation and new technologies, and the quality of the materials used during the manufacturing process were the key determining factors in our decision.”

The CDE solution

To guarantee precise control of sand cut points, SOMEVAM opted for a complete turnkey CDE solution. The CDE plant has the capacity to treat up to 200 t/h of sand, producing 100 t/h of silica glass sand for the glass industry, as well as a range of secondary products including fine silica sand for silica flour production, foundry sand, concrete sand and road base.

The installation features a combination of CDE equipment operating in synergy: an M4500 primary wash plant to classify materials, five high frequency Infinity Screens™, four attrition cells, spiral separators, CDE’s Counter Flow Classification Unit (CFCU), a nano-cyclone, magnet, four EvoWash™ sand washing units and an AquaCycle™ water management solution.

Combined, the system processes fine and coarse materials and eliminates contaminants to produce high-specification glass sand, according to CDE.

Cutting-edge technology

“Since its launch in 2014, CDE’s M4500 has quickly become popular and is installed in plants around the world,” CDE said. “This high-tech plant is compact, powerful, easy to use and economical.”

CDE’s cyclone technology uses centrifugal force for classifying materials rather than gravity, which retains every grain of viable sand in the system, according to the company. The design of the cyclone also makes it possible to establish multiple variable parameters to obtain unrivalled cut-point precision, CDE says.

Attrition, spirals and magnetic separation processes are used to remove contaminates from the product and maximise the silica content.

Bassem Idriss, Project Manager for the Europe and MENA region at CDE, explained: “The M4500 demonstrates the effectiveness of CDE’s cyclone technology and the flexibility of our process and engineering teams, who have designed the process to produce very high quality glass sand to meet SOMEVAM’s requirements.

“The hydrocyclones were built according to the specific needs of the client, based on analysis of the feed material carried out by CDE during the pre-project phase.

“The process water, loaded with undesirable fines, is removed at the level of the overflow of the cyclones while the treated sand enters the dewatering and stockpiling phase. With cutting points of incomparable precision, the products are treated according to the required standards and without risk of mixing.”

Efficient water management

To produce a clean sand product requires a good supply of clean water, with the new installation incorporating CDE’s water management system, the AquaCycle thickener with a capacity of 1,500 cu.m/h. Waste water from the plant is processed by the AquaCycle thickener which recovers up to 90% of the process water to be recirculated back into the washing plant, minimising the size and maintenance requirements of the settling ponds, which is particularly advantageous where the site is situated in Tunisia, CDE says.

Idriss continued: “In Tunisia, a hot and dry country, it is important to consider the difficulties of accessing fresh water. It is essential not to waste a drop of water. CDE’s AquaCycle allows SOMEVAM to recycle process water in a closed circuit for immediate reuse in the system.

“The wastewater, after passing through the deaeration chamber and after having been in contact with the flocculant injection, passes to the centre of the AquaCycle so that the flocculation process operates and acts on the sedimentation of the fines. The integrated flocculation unit allows precise dosing of premixed flocculant for effective decantation. A single motor drives the AquaCycle rake arms for optimal sludge treatment before disposal.”

The result

The CDE installation for SOMEVAM transforms the feed material into five high specification products with exceptional commercial value, according to CDE.

It produces glass sand (150-650 microns) and related products, including oversized (3 mm) ready to be used in water filtration systems, coarse sand (650 microns-3 mm) ready to be ground to make flour silica, ultrafine (30-150 microns) for ceramics or other industries, and iron-rich sand that can be used in sports fields. With a typical moisture content of 12%, the materials are market-ready straight from the belts, CDE says.

Sebri commented: “Our CDE solution has made a huge impact on the glass sand industry in Tunisia and in the North African market. It represents the most advanced technology available on the North African market and has enabled us to become ultra-competitive in an industry with extremely high-quality standards.

“Our glass sand is sold for the production of white glass, and the other fractions are sold for various industrial applications. Our quick return on investment was thanks to the power and efficiency of our CDE solution.”