Effects of Mud from a Zinc-plating Plant and Zeolite Saturated with Zinc on Portland Cement Hydration and Properties of Hardened Cement Pastes

Abstract

This work investigates the impact of mud from a zinc-plating plant and zeolite saturated with zinc on early hydration processes of ordinary Portland cement. During the first 48 hours of hydration, the addition of mud significantly affects the cement hydration kinetics. The partial replacement of cement with zeolite saturated with zinc ions, reduces the negative impact of mud on the hydration processes. Samples with the additions showed lower compressive strength than the sample without additions. With regard to the standard limits for this type of cement, mud shares are eligible up to 5 wt. % and a mixture of mud and saturated zeolite up to 10 wt. %.

Application of Isothermal and Isoperibolic Calorimetry to Assess the Effect of Zinc on Hydration of Cement Blended with Slag

“…The retarding effect of slag with increasing amounts is not so pronounced in pure cement. When slag and zinc are combined, a more significant retardation effect can be expected, with increasing slag amount due to the modification of the gel membrane [7,8,9,10,11,12,13]. Slag does not react as quickly as cement in the early stages of hydration, which results in lower maximum temperature; however, in the later stages of hydration, the pozzolans reaction especially produces more heat than the reactions of other components [37].…”

“…Zinc also prevents the formation of Ca(OH) 2 in the first week of C 3 A hydration. Chemical stabilization is more important than physical metal retention in the structure [12].…”

Influence of Zinc-Saturated Zeolite on Portland Cement Hydration Kinetics

“…Once zeolite is saturated with heavy metals, it becomes a harmful waste itself and should be treated in a way that does not endanger the environment [9]. A practical method of disposing saturated zeolites is to dispose them in a cement matrix [10][11][12]. However, the e ect of zeolite saturated with heavy metals on the hydration process of Portland cement is still not clear.…”

A Mass Transfer Analysis of Competitive Binding of Pb, Cd, and Zn from Binary Systems onto a Fixed Zeolite Bed

“…Among the most studied natural zeolites, clinoptilolite is the most abundant one in the removal of heavy metals due to its largest deposits, high cation exchange capacity, and great selectivity [17,26,27,28,29]. The advantage of natural zeolites compared to waste and bio-sorbents is that they can be regenerated and thus consecutively reused without a noticeable loss in capacity, as well as safely disposed of after exhaustion by solidification into building materials [8,30,31,32]. Our earliest investigations have been focused on the removal of different heavy metals (Zn, Pb, Cu) onto zeolite by the batch method, as it provides an assessment of essential operating parameters in a short time [33,34].…”