Estimation of Kinetic Parameters During the Treatment of Steelmaking Slag Expansibility Data

Abstract

Steelmaking slag (SS) is one of the largest generation waste in the integrated and semi-integrated plants, but it has application restrictions due to its high expansibility. To overcome these constraints, this research had as its main objective the reactions is kinetics parameters estimation that result in the expansion of SS using the Arrhenius global equation. It was obtained 12.5 kJ/mol for activation energy and 260.42% for the pre-exponential factor. It was also noted that the temperature significantly impacts the final expansion values, increasing them exponentially. Furthermore the time of expansion of the slag obey an asymptotic equation (Exp = a -b.c t ) whose results presented initially having a large expansion velocity, which tends to zero at times very long when the material has stabilized.

The Immobilisation of Heavy Metals from Sewage Sludge Ash in CO2-Cured Mortars

“…The thermogravimetric measurements, i.e., TG and DTG curves in the range from ambient temperature to 1000 • C for the SSA.P, SSA.M, and SSA.E specimens, are shown in Figure 4. The TG curves of the SSA.P and SSA.M mortars exhibit a gradual weight loss, while SSA.E presents a weight loss up to 650 • C, but presents similar behaviour to the EAFS raw material, showing a weight gain in the temperature range of 650 to 850 • C that is also probably due to the oxidation of metals presented in EAFS [26,27].…”

“…The TG-DTG results (Figure 3) showed different trends for each raw material. Although all the materials presented mass loss at a temperature of 1000 • C, the EAFS presented two steps of gain in weight, the first occurred between the temperature range of about 400 to 530 • C and the second from about 650 to 900 • C, probably due to the oxidation of metals [26,27].…”