The cementitious properties of natural Mg-rich olivine when reacted with a phosphoric acid solution are investigated, as a function of acid concentration and liquid/solid mass ratio. The obtained cements are composed of residual olivine crystals and amorphous silica nanoparticles dispersed in a dense and compact newberyite (MgHPO4∙3H2O) matrix. The latter was mostly formed by packed micrometric tabular crystals, although evidence of the presence of a fraction of amorphous MgHPO4 was also found. Water content in the raw mix was observed to play a pivotal role on the reaction pathway, either promoting porosity or hindering the crystallization of the products. Up to 57 % of olivine reactivity, whose dissolution was promoted by the curing temperature (60 °C) and low pH, was achieved. All in all, these results indicate that the industrial mineral olivine may serve a viable source of Mg for the production of phosphate cements.

中文翻译：

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橄榄石基 Mg-phosphate 水泥的凝固反应


研究了天然富镁橄榄石与磷酸溶液反应时的胶凝特性，作为酸浓度和液/固质量比的函数。获得的胶结物由残留的橄榄石晶体和无定形二氧化硅纳米颗粒分散在致密致密的纽伯瑞石 （MgHPO4∙3H2O） 基质中组成。后者主要由堆积的微米板状晶体形成，尽管也发现了存在少量无定形 MgHPO4 的证据。观察到原料混合物中的水分含量在反应途径中起着关键作用，要么促进孔隙率，要么阻碍产物的结晶。实现了高达 57% 的橄榄石反应性，其溶解受到固化温度 （60 °C） 和低 pH 值的促进。总而言之，这些结果表明，工业矿物橄榄石可能是生产磷酸盐水泥的镁的可行来源。