Haohua Yuhang Chemical Co Ltd recently announced two technology breakthroughs: a process for mercury ion removal from waste hydrochloric acid, and salt water deiodizing in the production of ionic membrane caustic soda. The technologies will help reduce mercury discharge and iodine content. Haohua is the first chlorine-alkali enterprise to master the technology, the company reported.
Large amounts of mercury-containing hydrochloric acid wastes are produced from PVC production. To reduce the mercury content and recycle mercury resources, Haohua has applied an ion exchange method to treat hydrochloric acid wastes and decontaminate regenerated mercury-removed liquid. It reduced the mercury content in waste hydrochloric acid from 30 milligrams per liter to 0.1. Haohua reported that the program can generate an annual economic benefit of more than 10 million yuan.
In producing ionic membrane caustic soda, the iodine in the salt water will shorten the lifespan of the ionic membrane and increase costs. Currently, domestic chlorine-alkali enterprises do not have de-iodizing technology and facilities. Haohua last year adopted a reduction blowing method to remove iodine from salt water. The company reduced iodine content from 0.6 milligrams per liter to 0.1 milligrams per liter. The enterprise also set up an online iodine analysis system geared for saturated brine. It plays a positive role in monitoring iodide and protecting ion-exchange membrane electrolyzer in brine, the company said. The project is expected to generate an economic benefit of 3 million yuan.