The international journal Microchemical Journal recently published a research paper titled "Research on Steel Slag Desulfurization and Comprehensive Treatment of Saline-Alkali Land Based on the Circular Economy Concept." The paper proposes an ecological restoration model of "solid waste utilization — waste gas treatment — by-product reclamation of desert land," exploring a new path for China's steel slag valorization and ecological treatment. As the first author, Shi Hanxiang, Chairman of Ningbo Taiji Environmental Protection Equipment Co., Ltd. and Chief Expert of Zhejiang Hanxiang Research Institute Co., Ltd., led the team to complete this technological innovation, which offers both environmental value and economic potential.
As a national-level SRDI "Little Giant" enterprise, Ningbo Taiji Environmental Protection Equipment Co., Ltd. has developed the DS Multiphase Reactor with a desulfurization efficiency of 99.9%. Since 2015, Shi Hanxiang and his team, through technological innovation, have further processed the spent steel slag and fly ash that absorbed sulfur dioxide after desulfurization into a soil amendment, used to reclaim deserts and saline-alkali land. Scientific testing and field trials show that this amendment delivers a marked fertilizing effect.
This circular economy chain has so far been piloted at a flue gas desulfurization project in Inner Mongolia and in a systematic comprehensive saline-alkali land treatment project. The Microchemical Journal paper uses the Inner Mongolia project as a case, describing the process flow, implementation plan, treatment outcomes, and risk assessment, and rigorously evaluating the project's economic and environmental benefits. The data in the paper show that a 1:1 replacement of limestone in the desulfurization absorbent would consume about 150 million tons of steel slag annually; the resulting by-products could also be used to amend saline-alkali sandy wasteland, offering a new method for saline-alkali land treatment and a sustainable outlet for the large annual volume of new steel slag solid waste. While saving energy, reducing emissions, and restoring the environment, this model is expected to add a substantial amount of available land resources.
At present, industrial solid waste — represented by steel slag, power plant fly ash, and non-ferrous metal slag — has become a severe challenge to the global ecological environment. "After years of practice and exploration, we must follow the green, low-carbon circular economy path to resolve the contradiction between economic development and environmental protection, restore natural ecological balance, and safeguard the long-term interests of future generations," said Shi Hanxiang.
After the relevant technologies were applied at the Baogang Qinghua desulfurization project in Inner Mongolia, monitoring data shows that the enterprise reduces sulfur dioxide emissions by approximately 7,000 tons, consumes about 17,000 tons of steel slag powder, and saves 16,000 tons of limestone annually. To date, more than 200 enterprises in over 10 provinces, spanning hazardous waste, steel, non-ferrous metals, chemicals, and various industrial furnaces, have adopted this environmental technology.
Microchemical Journal, which publishes comprehensive research in chemistry and analytical chemistry, is indexed in the SCIE database and enjoys strong academic influence.
(By Jiang Tianjiao, reporter, Economic Daily)
