Slag treatment at Kardemir integrated iron and steel works

Microwave-Supported Leaching of Electric Arc Furnace (EAF) Slag by Ammonium Salts

“…(3) The leaching behaviors of magnesium and calcium ions affected by different leaching parameters are similar and the concentration of aluminum, iron and phosphorus can be neglected. (4) Calcium ion is probably not precipitated in the real leaching solution from steel slag by NH 4 Cl solution as its concentration is less than 0.32 mol/L. However, the concentration of magnesium ion starts to drop sharply when the pH value is higher than 10 and it has precipitated completely at pH value of 11.6.…”

“…In addition, the concentration of calcium in the solution, 0.32 mol/L when the pH value is 11.6, is still high, which indicates that the calcium ion is probably not precipitated in the real leaching solution from steel slag by NH 4 Cl solution as the calcium concentration of the real solution is less than 0.32 mol/L (Figure 7). This is important to obtain high carbonation efficiency, since only dissolved Ca can be used for CO 2 sequestration.…”

“…The calcium leaching ratio from the EAF slag by NH 4 Cl under different leaching environments are shown in Figure 1. It can be seen from Figure 1a that the calcium leaching ratio rose significantly at the initial period (5 min) and then tends to the maximum value, which attains~87% with 120 min leaching at 100 • C. Figure 1b is the variation of calcium leaching ratio with leaching time at constant temperature in a microwave field.…”

“…A 500 mL experimental solution was set up containing 0.5 mol/L CaCl 2 , 0.2 mol/L MgCl 2 , 1 mol/L NH 3 ·H 2 O and 2 mol/L NH 4 Cl, and then the configured solution was shaken up and left standing for 24 h, after which the configured solution was filtered, and the filtrate was selected as the solution for the removal experiment of magnesium ion by adding 15 mol/L sodium hydroxide solution.…”

“…Furthermore, the iron and steel industry is recognized as one of the largest CO 2 emission industries with total amounts of 1500~1600 Mt CO 2 emission [3]. Currently, the waste steelmaking slag are mainly used as fluxing agent of iron and steel smelting [4,5], fertilizer of agricultural production [6,7], construction materials (such as slag cement, brick, concrete and construction aggregate) [8], soil conditioner [9], as well as adsorbent of environmental protection [10]. However, for these applications only a small part of the slag can be utilized, especially in China, where the utilization rate of steel slag is only 22%, which is far behind the developed countries [11].…”