Ivanova Tatiana K, Kremenetskaya Irina P, Marchevskaya Valentina V, Slukovskaya Marina V, Drogobuzhskaya Svetlana V
I.V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia.
Laboratory of Nature-inspired Technologies and Environmental Safety of the Arctic, Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia.
Materials (Basel). 2022 Dec 8;15(24):8785. doi: 10.3390/ma15248785.
The influence of structural features of three serpentine-group minerals (antigorite, chrysotile, and lizardite) on the hydration of heat-treated materials and the formation of magnesium silicate binder has been studied. Initial serpentine samples have been fired in the interval 550-800 °C with a step of 50 °C; acid neutralization capacity (ANC) values have been determined for all samples. Antigorite samples (SAP) have exhibited a maximum reactivity at a temperature of 700 °C (ANC 7.7 meq/g). We have established that the acid-neutralizing capacity of chrysotile and lizardite samples in the temperature range of 650-700 °C differ slightly; the capacity varied in the interval of 19.6-19.7 meq/g and 19.6-19.7 meq/g, respectively. The samples obtained at optimal temperatures (antigorite-700 °C, lizardite, and chrysotile-650 °C) have been studied. Heat-treated serpentines have interacted with water vapor for a year; serpentine hydration has been investigated. The strength characteristics of the resulting binder agents were studied after 7, 28, 180, and 360 days. Upon hardening within 7 days, the strengths of the SAP and SCH samples have been almost the same (2.2 MPa), whereas this indicator for the SLH and SLK samples has been significantly lower (0.5 MPa). After hardening for over a year, the chrysotile sample SCH had the highest strength (about 8 MPa), whereas the strength of antigorite SAP was 3 MPa. The samples of initial, heat-treated, and hydrated heat-treated serpentines have been studied using XRD, differential scanning calorimetry, and surface texture analysis. The serpentine structure is crucial in destroying the mineral crystal lattice during heat treatment. In contrast to heat-treated chrysotile and lizardite, antigorite did not adsorb water. Structural features of chrysotile provided the highest compressive strength of the binding agent compared with antigorite and lizardite. The acid-neutralizing ability of lizardite was noticeably higher than antigorite, whereas its compressive strength was lower due to the layered mineral structure and impurities. We have established that the minerals' structural features are crucial for the hydration of heat-treated serpentines; the structure determines material utilization in various environmental technologies.
研究了三种蛇纹石族矿物（叶蛇纹石、纤蛇纹石和利蛇纹石）的结构特征对热处理材料水化及硅酸镁粘结剂形成的影响。将初始蛇纹石样品在550 - 800℃区间内以50℃步长进行煅烧；测定了所有样品的酸中和能力（ANC）值。叶蛇纹石样品（SAP）在700℃时表现出最大反应活性（ANC为7.7 meq/g）。我们发现，纤蛇纹石和利蛇纹石样品在650 - 700℃温度范围内的酸中和能力略有差异；其能力分别在19.6 - 19.7 meq/g和19.6 - 19.7 meq/g区间内变化。对在最佳温度下（叶蛇纹石 - 700℃、利蛇纹石和纤蛇纹石 - 650℃）获得的样品进行了研究。热处理后的蛇纹石与水蒸气相互作用了一年；对蛇纹石的水化进行了研究。在7天、28天、180天和360天后研究了所得粘结剂的强度特性。在7天内硬化时，SAP和SCH样品的强度几乎相同（2.2 MPa），而SLH和SLK样品的该指标则显著较低（0.5 MPa）。硬化一年多后，纤蛇纹石样品SCH的强度最高（约8 MPa），而叶蛇纹石SAP的强度为3 MPa。使用X射线衍射、差示扫描量热法和表面纹理分析对初始、热处理和水合热处理后的蛇纹石样品进行了研究。蛇纹石结构在热处理过程中破坏矿物晶格方面至关重要。与热处理后的纤蛇纹石和利蛇纹石不同，叶蛇纹石不吸附水。与叶蛇纹石和利蛇纹石相比，纤蛇纹石的结构特征使粘结剂具有最高的抗压强度。利蛇纹石的酸中和能力明显高于叶蛇纹石，但其抗压强度因层状矿物结构和杂质而较低。我们发现，矿物的结构特征对热处理后蛇纹石的水化至关重要；该结构决定了材料在各种环境技术中的利用情况。
