Aqueous carbonation of the potassium-depleted residue from potassium feldspar–CaCl2 calcination for CO2 fixation

Abstract

Based on the academic thought of carbon capture and utilization, a novel process to integrate the potassium extraction from the insoluble potassium feldspar, industrial waste utilization, and the subsequent CO 2 fixation using the resultant potassium-depleted residue was proposed in our previous studies. The potassium-depleted residue comprises several Ca-bearing phases, namely wollastonite (CaSiO 3 ), pseudowollastonite (Ca 3 Si 3 O 9 ), Clmayenite (Ca 12 Al 14 O 32 Cl 2 ), and anorthite (CaAl 2 Si 2 O 8 ), which are potential materials for fixation of CO 2 via carbonation. In this study, carbonation of the residue was examined with focuses on the effects of reaction temperature, initial CO 2 pressure, particle size of the residue, and reaction duration on the carbonation of these Cabearing phases. The results demonstrated that both the temperature and CO 2 pressure significantly affect the carbonation, while the residue particle size has only minor influence. At 1 MPa CO 2 pressure, the carbonation of these components was dominant at different reaction temperatures. Almost complete carbonation of the pseudowollastonite could be achieved at 75°C, while significant carbonation of the wollastonite takes place above 100°C. However, the Cl-mayenite and anorthite are incapable of carbonation even at 200°C. Increasing the CO 2 pressure to 4 MPa can lead to a distinct carbonation of the Cl-mayenite at 150°C but the anorthite remains untouched. At 1.5 MPa CO 2 pressure and 150°C, with the increasing reaction time, the following Ca-bearing species were successively carbonated: first the pseudowollastonite in 5 min after the reaction started, the wollastonite in 5-15 min, and then simultaneously the wollastonite and the pseudowollastonite in 15-45 min, while the carbonation of Cl-mayenite do not begin even after 120 min. A priority sequence of carbonation of these Ca-bearing minerals was determined as follows: pseudowollastonite [ wollastonite [ Cl-mayenite [ anorthite. The trend is in agreement with the results of thermodynamic calculation. Compared to the carbonation of natural wollastonite, the synthesized wollastonite contained in the potassium-depleted residue seems to be more active in carbonation.

Extraction of potassium from K-feldspar via the CaCl2 calcination route

“…Other studies reported more complicated product phases, including Ca 12 Al 14 O 33 and Ca 12 Al 14 O 32 Cl 2 [34,38], appearing in the CaCl 2 /K-feldspar system. In their investigations, air was directly introduced into the calcination system without drying pretreatment.…”

Sustainable Process for the Extraction of Potassium from Feldspar Using Eggshell Powder

“…Most of the literature that has adopted the roasting–leaching process has suggested calcium chloride as the best roasting agent on the basis of potassium recovery. ,− In all these studies, laboratory-grade calcium chloride was used.…”

Thermodynamics study on the generation of electricity via CO2-mineralization cell

“…As is well known, there are several methods of reducing CO 2 emissions in the atmosphere, such as the CO 2 capture and storage (CCS) technology or by utilizing CO 2 as a chemical raw material (Aresta 2010;Barrow 1973;Hou et al 2014;Klotz and Rosenberg 1950;Liu et al 2014;Sheng et al 2015;Xie et al 2014aXie et al , 2015aZhang et al 2015b). To mitigate the adverse effect on the environment and ensure the sustainable use of fossil energy, numerous studies have been carried out to sequestrate CO 2 underground Zhang et al 2015a).…”