Characterisation of dolomites before and after reactivity measurement with HCl solution

The aim of this study was to compare different types of dolomites thro ugh batch reactivity experiments betwee n HCl and dolomite powders, and ex-situ characterisation of the part icles before and after dissolu tion. Sedimen tary do lomites wer e observed t o have higher initial reactivities than metamorphic ones with sufficiently low calcite concentrations (<6% according to our regression model). In addi tion, the initial reactivities of the me tamorphic dolomit es were dependent on calcite conc entration and could excee d those of the sedimenta ry dolomites. A regre ssion model is present ed for the dependence of initial reactivity on mineral composition and type of o rigin (sedim entary/m etamorphic). The s amples wit h the highest initia l reactiv ities had also th e largest BET (Bruna uer, Emm et, Teller) surface areas obtained with nitrogen physisorption. Yet our data indicates that mineral composition of the dolomite has a great er influence on the initial reactivity t han the BET surface area. F urthermore, it w as found that the surface of sediment ary dolomites, unlike the surface of metamorphic dolomites, becomes porous during dissolution.