2. Brief introduction of the project
This project belongs to the technical field of "three wastes treatment and comprehensive utilization". Aiming at the major demand for the sustainable development of the heavy metal industry and the recycling of resources, we have developed key technologies for resources and harmless treatment of industrial vanadium chromium waste residues and ammonia-nitrogen contained wastewater with heavy metal, and realized the high-value reuse of valuable resources in waste and the low-cost advanced treatment of pollutants, providing necessary new technologies support for promoting scientific and technological progress in this field, transforming pollution control models, developing new industries for environmental protection strategies, and completing the national 12th Five-Year Plan for heavy metal and ammonia nitrogen emission reduction indicators.
Vanadium-chromium waste residue and ammonia nitrogen wastewater with heavy metal are typical pollutants produced by heavy industries such as iron and steel, nonferrous metals or batteries. Their high emission intensity and lack of treatment technology have severely restricted the normal development of related industries. In view of the current situation that the above two types of wastes have the dual characteristics of valuable resources and strong environmental hazards and lack of suitable treatment technologies, we have independently developed key technologies and products with green separation and pollution control as the core to achieve low cost and high efficiency of waste treatment. The main technical innovations and invention points are: (1) In view of the current situation of similar chemical properties of vanadium chromium and lack of effective separation technology, a new extraction system for the efficient separation of vanadium chromium (including primary amine extractant LK-N21 and modifier LK-N21X) solved the theoretical and technical bottleneck of the prevention and control of intermediate layer, and realized the key technical breakthrough of rapid and deep separation of vanadium and chromium; (2) Process and equipment of semi-continuous back extraction has been developed for the heat-sensitive and easily emulsified vanadium-rich organic phase, achievimg long-term stable operation of vanadium and chromium extraction separation; (3) For the treatment of high-salt heavy metal ammonia nitrogen wastewater treatment, innovative research and development of pharmaceutical enhanced pyrolysis complex-distillation technology and anti-fouling and high operation elastic tower internals, achieving recycling of more than 99.9 % of ammonia and more than 90 % of heavy metals. It greatly improves the removal rate of ammonia nitrogen in water (one step to reduce ammonia nitrogen from more than 30,000 mg/L to less than 15 mg/L), reduces energy consumption (more than 20 % of energy saving), and ensures stable compliance  of wastewater; (4) We proposed a clean process and integrated system of "halogen-free sodium roasting, vanadium chromium extraction separation, ammonia medium circulation, zero water discharge, and energy cascade utilization" for the treatment of vanadium-chromium waste residues, achieving a total resource utilization rate of over 95 % with 10,000-ton scale industrial application, forming a high-value clean utilization of vanadium chromium waste residue with complete independent intellectual property rights and a resource package and harmless process of ammonia nitrogen waste water containing heavy metals.
The project has applied for nearly 30 patents, including 17 authorized invention patents, forming 2 new products. The complete set of technology was used to estabiled the world’s first high-value vanadium-chromium waste residue industrialization project (16,000 t/a) in Liaoning Province in 2009. The resource utilization rate of the main elements of vanadium, chromium, and phosphorus increased from less than 30 %  to more than 90 %, without discharge of wastewater in the process.In addition, the pharmaceutical enhanced pyrolysis complexation-rectification technology has also completed 14 advanced demonstration projects in rare earth, nickel cobalt, copper, vanadium, molybdenum, zirconium, niobium and tantalum industries, all achieving the recycling of heavy metals and ammonia nitrogen and stable wastewater standards.
The results of this project have effectively served China's non-ferrous metallurgy, heavy metal materials processing and other industries, and have produced significant economic, environmental and social benefits. For example, the demonstration project has accumulated 900 new jobs and reduced toxic heavy metal waste residues by 50,000 tons. More than 4 million tons of wastewater, nearly 30,000 tons of ammonia, 3,500 tons of heavy metals such as vanadium, nickel, chromium and molybdenum, saving more than 1 million tons of water, and creating direct economic benefits of more than 1 billion yuan. The development and promotion of the project will also provide industrialized technical support for the use of other vanadium-containing chromium secondary resources, the treatment of high-concentration ammonia-nitrogen wastewater and the clean utilization of high-chromium vanadium-titanium magnetite, which is of great significance.
The vanadium-chromium waste residue resource technology has won the first prize of the Liaoning Provincial Technology Invention Award in 2011, and the heavy metal-containing ammonia-nitrogen wastewater treatment technology has won the first prize of the Ministry of Environmental Protection Science and Technology Progress Award in 2012.
7、 Main complete person