Fig. 8From: Crystallization of calcium carbonate in a large-scale push–pull heat storage test in the Upper Jurassic carbonate aquiferTypical particle concentration during injection (left picture) and production (right picture) stages. Needle-like aragonites are marked by red ellipses. Spherical particles (here iron and zinc hydroxides) are marked by green circles. The particle concentration clearly increased during production. Here, at \({T}_{\mathrm{Inj}} = 110\), aragonite needles were dominatingBack to article page