A challenging — and potentially pricey — environmental compliance issue faced Indiana steel producer NLMK: how to dispose of sludge.
To solve this issue, the company turned to General Electric’s advanced water treatment technologies to dewater sludge from the spray water system thickener. After a year of implementation, the mill eliminated 2,050 tons of waste and reused 500,000 gallons of water as make up to other cooling systems. It also saved $210,000 annually, primarily from reduced sludge hauling and disposal costs.
GE recently honored NLMK with the Return on Environment (ROE) award to recognize the company for its reductions in water usage and waste as well as its positive environmental impact and cost savings.
“This project underscores the substantial environmental and economic benefits that industrial companies, including steel manufacturers, can achieve when they make an investment in water reuse and waste reduction technologies,” said Amy Ericson, global leader, chemical monitoring solutions—water and process technologies for GE Power. “Water usage in the steel industry is considerable, and implementing water recycling strategies can reduce resources and environmental impact.”
Previously, the wet sludge was collected in a silo and periodically hauled off-site. The idea was to take this sludge and process it using a rotary vacuum filter that is coated with a layer of diatomaceous earth.
As the filter rotates, it draws a layer of sludge that is subsequently dried before being scraped off and deposited into a container. Because most of the water has been removed from the sludge, the volume and weight of sludge disposed is greatly reduced resulting in disposal cost savings.
GE’s water treatment technology is also helping a Canadian oil refinery reuse 100 percent of its water.
Federated Co-Operatives Limited’s Co-op Refinery Complex in Regina, Saskatchewan, Canada, earlier this year began installing GE’s water recycling technology. The wastewater improvement project will enable the refinery to clean all of its wastewater on-site.
Once fully operationally, the Co-op Refinery Complex will be the only refinery in North America to recycle 100 percent of its wastewater for steam production, which is used for heating, hydrogen production, to power equipment and for cooling towers, GE says.
Bluefield Research recently published a report that forecast US water reuse capacity to increase 58 percent in the next 10 years. The report said CAPEX investment in reuse is expected to total $11 billion between 2016 and 2026, which represents a major business opportunity for water technology companies.