大理岩石刻文物黑色结壳清洗研究

Study on the cleaning of black crusts on ancient marble carvings

大理岩是古代石刻和建筑的主要石材之一。随着近现代工业发展,很多大理岩石刻文物表面出现了大量黑色结壳——不仅严重影响了文物外观审美,而且会不断吸附各种污染物,吸收更多的辐射热量,造成文物的进一步劣化,因此亟需清洗。在前期对北京地区石刻文物本体及黑色结壳科技分析的基础上,选用碳酸铵法、乙二胺四乙酸法、物理法进行清洗试验用于对比,并于北京不同区域的6处典型石刻上进行现场试验,根据实际情况做出优化改良。采用便携式X射线荧光光谱仪、分光测色仪、显微镜和离子色谱仪对清洗前后状态及可溶盐含量进行评估,结果表明碳酸铵法对大理岩石刻文物表面黑色结壳具有较好的清洗效果,清洗方案比较高效合理,有助于相关石质文物病害的清洗和保护。

Marble is one of the main materials used for ancient stone carvings and constructions.Many black crusts have appeared on the surface of marble relics during the period of industrial development.These not only reduce the artistic value seriously,but also lead to further deterioration through continuous absorption of various pollutants and more radiation heat.Therefore,cleaning measures are urgently needed.Based on the previous studies on marble carvings and black crusts in Beijing area,the ammonium carbonate method,ethylene diamine tetraacetic acid method and mechanical method were used to carry out cleaning trials for conparison.Furthermore,on-site tests were applied to six typical stone carvings at different places in Beijing to optimize the whole process.Instruments including a portable X-ray fluorescence spectrometer,a colorimeter and a microscope were used to evaluate the effects before and after cleaning.The contents of soluble salts in carvings were analyzed using ion chromatography.The results show that the ammonium carbonate method had the best cleaning effect on the black crusts on marble stone relics.A more efficient and reasonable cleaning scheme was thus obtained,which is helpful to the conservation of stone relics.