DETERMINATION METHOD OF SUITABLE AMOUNT OF SULFAMIC ACID FOR REMOVING NOx PRODUCED IN STS PICKLING PROCESS

摘要

PURPOSE: A determination method of a suitable amount of sulfamic acid for removing NOx produced in STS pickling process by calculating a proper amount of sulfamic acid aqueous solution injected into a pickling solution is provided. CONSTITUTION: In a method for removing NOx in a stainless steel pickling process using nitric acid and hydrofluoric acid, the method is characterized in that NOx generated during pickling is removed by continuously injecting a sulfamic acid aqueous solution into a pickling solution at an injection flow rate satisfying the following mathematical expression 1: F/X(NOx)>=C, where F is an injection flow rate (ml/min) of the sulfamic acid aqueous solution, X(NOx) is a generation amount of NOx (mg/m¬3), and C is proportional constant for sulfamic acid concentration, wherein the proportional constant C is a slope calculated from the center of a graph illustrating the generation amount of NOx and injection flow rate of the sulfamic acid aqueous solution according to the sulfamic acid concentration.