Tag Archives: OMV

OUTPUT AT OMV STILFONTEIN BOOSTED BY UPGRADES

A range of upgrades at OMV’s aggregate and sand plant at Stilfontein in North West province has led to a 40% capacity growth over just 18 months.

OMV’s plant processes quartzite rock dumps generated from shaft-sinking in the area to produce road construction material. While production capacity could previously be pushed to about 1,000 tonnes a day, the plant’s daily output now regularly reaches some 1,400 tonnes.

One of the first improvements was the installation of a 100 metre overland conveyor extension from the dump to the feed box. This improved productivity and overcame the loading constraints experienced previously with the use of front-end loaders. A new feed box was also installed – with its own six metre conveyor belt – to feed the overland conveyor. This addition reduced excessive wear and tear, improving uptime on that part of the plant.

Production has also been improved with the incorporation of a vibrating pan feeder on the secondary crushing plant, regulating the flow of material onto the conveyor belt. Supplied by Weir Minerals Africa and installed by the OMV team, the feeder was the first step in the automation of the secondary crushing process.

A programmable logic controller (PLC) and human machine interface (HMI) has been added to the circuit to automatically regulate the feed box. This allows the choke-feeding of the crusher, which is difficult to accomplish manually.

To raise sand production, a deep cone thickener was installed to extend fines separation. Among the benefits of the new fines separator is that it reduces the amount of saleable material discharged to tailings. It recovered about 10% of saleable product previously discarded into the tailings pond, and contributed to the plant’s sand production capacity rising from 25 to 33 tonnes per hour. This step also reduced the plant’s environmental impact by reducing the quantity of tailings.

ECONOMICAL NEW FINISHING PLASTER SETS NEW BENCHMARK

MetaCote is a new, smoother and more economic finishing plaster that promises to take the South African market by storm.

According to Gavin Coulson, managing director of Metadynamics, the innovative product sets a new benchmark for smoothness and consistency. It is also a high purity product, containing 95% synthetic gypsum.

“MetaCote is a locally developed, high-strength gypsum plaster used for basecoat and finishing plaster,” says Coulson. “In our trials, users have been particularly impressed by its smoothness and longer workability. It has certainly exceeded their expectations.”

He says it is ideal as a multi-purpose plaster for internal applications onto brickwork, concrete blocks and dry walling. It is also a perfect finishing plaster for sand-cement base coats. Layers can be finished from 3 mm to 6 mm in thickness.

“We are sure our competitive pricing will make MetaCote an attractive option not just for the larger contractors, but also for smaller and emerging contractors,” he says. “We are equally confident that the product will satisfy the end-consumer who wants a superior finish to their structures. It will at the same time add value to the businesses of contractors and subcontractors.”

It will be available at major building material retail outlets in 25 kg and 40 kg bags for easy mobility.

Coulson also emphasises the environmental benefit inherent in Metacote. It comprises synthetic gypsum, rather than natural gypsum which has to be mined. South Africa’s natural gypsum deposits are located in the Northern Cape which adds transportation costs to the carbon footprint when this is used. The synthetic gypsum used in MetaCote, by contrast, is sourced as a by-product from phosphate fertiliser manufacture.

“Synthetic gypsum is also more eco-friendly as a binder, when compared to cement,” he says. “The production of one ton of gypsum binder generates one tonne less CO2 emissions and avoids the depletion of a further 1,5 tonnes of natural resources when compared to cement.”

OMV RAISES OUTPUT AND QUALITY AT GYPSUM PLANT

After significant upgrades and expansions to its manufacturing facility at Potchefstroom, leading gypsum supplier OMV has boosted its supply capacity while improving its gypsum quality.

OMV produces synthetic gypsum from the phosphate waste-product of the fertilizer industry, supplying the cement, agricultural and industrial sectors. According to OMV mechanical engineer Marinus van den Berg, the company has upgraded and automated its washing plant, while also adding a kiln drier and a calcining plant.

“The redesign of the washing plant included changing to a continuous lime batching system,” van den Berg says. “This improves the controllability of the process and the product quality. Standard deviations of the pH levels – a primary control parameter – are now down to 0,2 pH points.”

The washing plant upgrade meant full automation and higher availability. It also included a completely new laboratory, now staffed with a chemical engineer and chemical technician to focus on quality control. He emphasises the peace of mind that comes with a product of consistent quality. For industrial customers in particular, a dependable standard means less need to adjust their process in response to variabilities in the gypsum feed.

A key enhancement of the gypsum facility has been the addition of a rotary drying kiln. This allows reliable supply to customers even during the rainy months.

“The kiln reduces the moisture content in our gypsum by an extra 10%,” he says. “This has made our year-round supply more reliable, while the drier material also saves on road transport costs.”

An important part of the technology employed in the kiln is optimised fuel economy for lower carbon emissions. Along with the kiln installation has come the construction of an undercover gypsum warehouse with 30,000 tonne capacity. Dedicated stockpiles within the warehouse further enhance the customer experience.

“All these facilities operate within our total quality management system,” he says. “We continually optimise processes so we can pass the cost savings on to customers.”

Most recently completed is the calcining plant, which adds value to the gypsum product by producing a high quality Plaster of Paris. After extensive research into available technologies, OMV was able to construct and commission the plant in less than a year. It has also enhanced certain automation elements in the calciner.

“Once again, our focus has been on low process variability,” says van den Berg. “Through strict controllability, we have achieved high-quality and consistent output to open new markets.”