Tong and Wang Herit Sci (2019) 7:70 https://doi.org/10.1186/s40494-019-0312-8 RESEARCH ARTICLE Open Access Study on fring temperature of the Song Dynasty (960–1279AD) greenish-white porcelain in Guangxi, China by thermal expansion method Yongdong Tong1,2 and Changming Wang2* Abstract The original fring temperatures of porcelain pieces unearthed from Tengxian Zhonghe kiln, Rongxian Chengguan kiln, Beiliu Lingdong kiln and Guiping Xishan kiln from the Song Dynasty (960–1279AD) of Guangxi were preliminarily studied by thermal expansion method. The experiment results show that the average fring temperature of Zhonghe kiln is 1186 °C (standard deviation 59 °C), the fring temperature relatively concentrated and low. The average fring temperature of Chengguan kiln is 1233 °C (standard deviation 46 °C), with the majority above 1200 °C, indicating that the kiln had a high and concentrated fring temperature. The average fring temperature of Lingdong kiln is 1250 °C (standard deviation 87 °C), the fring temperature are in a broad spectrum. The fring temperatures of Xishan kiln are mostly over 1300 °C (average 1307 °C, standard deviation 75 °C), which are generally considered very high, and the highest one it can go up to 1456 °C, which is the highest fring temperature of ancient Chinese ceramics known to date. Compared with the fring temperature of porcelain in other regions of China in Song Dynasty, it can be con- cluded that the high-temperature technology of Guangxi porcelain kilns was equal to or even advanced than other kilns. In the light of these fndings, we conclude that the ancient Guangxi region of China did not lag behind the central plains in terms of ceramic fring technology and culture. Keywords: Thermal expansion method, Song Dynasty, Greenish-white porcelain, Firing temperature Introduction and research aim kilns for porcelain production not a single kiln) include Te porcelain industry in Guangxi boomed during the Tengxian Zhonghe kiln, Rongxian Chengguan kiln and Song Dynasty (960–1279AD), and dominated by two Beiliu Lingdong kiln in the Beiliu river basin, the Guip- kiln systems of celadon and greenish-white porcelain. ing Xishan kiln and Weiyang kiln in Guiping area and Te celadon kiln sites are concentrated in northern the Tudong kiln in upper reaches of the Wusi river. Guangxi, mainly producing porcelain with cyan glaze Te geographical locations of the four kilns (Tengxian and green glaze. Te greenish-white porcelain kiln sites Zhonghe kiln, Rongxian Chengguan kiln, Guiping Xis- are concentrated in the southeast of Guangxi, consist- han kiln and Beiliu Lingdong kiln) studied in this paper ing of three distribution areas: Beiliu river basin, Guip- are shown in Fig. 1. According to archaeological materi- ing and the upper reaches of Wusi river. Tere are more als and studies, Zhonghe kiln existed between the mid- sites in Beiliu river basin than the other two areas. Te dle Northern Song Dynasty (960–1127AD) and the late main kilns (a whole production center comprising several Southern Song Dynasty (1127–1279AD) [1]; Cheng- guan kiln emerged at about the same time or a bit ear- lier than Tengxian Zhonghe kiln, which began in the *Correspondence: [email protected] 2 Archaeometry Laboratory, Guangxi University for Nationalities, middle Northern Song Dynasty, and ended in the middle Nanning 530006, Guangxi, China Southern Song Dynasty, the late Northern Song Dynasty Full list of author information is available at the end of the article through the early Southern Song Dynasty are its heyday © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Tong and Wang Herit Sci (2019) 7:70 Page 2 of 10 Fig. 1 Geographical distribution map of main greenish-white porcelain kiln sites of Song Dynasty in Guangxi, China [1]; Lingdong kiln fourished in the early Southern Song Dynasty [2]; Guiping kiln appeared in the early Northern Song Dynasty, close to Five Dynasties (907–960AD), and ended in the early Huizong period (1100–1126AD) [3]. Tese kilns used to produce porcelain with a large quan- tity, high quality and superb techniques. Porcelain prod- ucts were in various types and forms and made in a neat and delicate way, with a white and solid porcelain body, bright and translucent glaze, rich and colorful decora- tion techniques and patterns, and local characteristics. Figures 2 and 3 show the products of Zhonghe kiln and Chengguan kiln respectively. Fig. 2 Bowl with printing motif of Zhonghe kiln (now is in the Te greenish-white porcelain of the Song Dynasty in Tengxian Museum) Guangxi can be comparable to that of Jingdezhen for same period in terms of quality, and with a better tech- niques in certain areas. In particular, the high-temper- ature copper green glaze of the Rongxian Chengguan on the analysis of chemical components. For example, kiln is an innovation in the fring technology of Chinese Cheng et al. [4, 5], Zhu et al. [6, 7] and Ming et al. [8] ceramics during the Song Dynasty [1], which was of great studied the chemical composition of the greenish-white signifcance in the history of Chinese ceramics. However, porcelain in diferent areas of China by using various there is no record of the Guangxi greenish-white porce- advanced techniques. However, there are very few stud- lain in the ancient Chinese literature, and few complete ies concerning the determination of original fring tem- products currently exist. Terefore, little has been known peratures of Chinese ceramics. Te fring temperature is of these porcelains. an important parameter to refect the level of porcelain Prior scientifc researches on the ancient Chinese production, which is of great signifcance to the study of greenish-white porcelain have been mainly focused high-temperature technology of ancient ceramics and Tong and Wang Herit Sci (2019) 7:70 Page 3 of 10 the fring technology and porcelain research. Samples of porcelain pieces from four major greenish-white porce- lain kilns, including Tengxian Zhonghe kiln, Rongxian Chengguan kiln, Beiliu Lingdong kiln, and Guiping Xis- han kiln, were selected and utilized as research objects in this study. Experimental equipment and samples Instrumentation Te DIL 402PC thermal dilatometer made by the Ger- man company NETZSCH was used in this study. Fur- nace body: SiC (0–1600 °C/50 K/min); Sample holder: tubular Al2O3 holder. Te thermal analysis software is the Netzsch Proteus Termal Analysis at version 6.1.0/12.08/2015. Fig. 3 Incised decoration jar of Chengguan kiln (now is in the Sampling information Rongxian Museum) Ten samples from the Zhonghe kiln were selected, which were collected at four diferent sites: Lishankou, Ping- touling, Feimaling, Feimaling primary school and Zhi- maping. Six samples from the Chengguan kiln were kilns. In the aspect of studying and determining the fr- selected, which were collected from the substation and ing temperature of ancient ceramics, various methods rosin factory. Six samples from the Lingdong kiln were and equipments were utilized including the magnetic selected, which were collected from Lingdong kiln Y1. susceptibility method [9, 10], Mössbauer spectra [11, Ten samples from the Xishan kiln were selected, which 12], thermogravimetric diferential thermal analysis [13], were collected from Xungao kiln site and Guanchong scanning electron microscope [14], electron paramag- kiln site near the park and Guishan village kiln site near netic resonance measurement [15–17] and the thermal the Guiping distillery. Some sample pictures are shown in expansion method. Te thermal expansion method has Fig. 4. Te sample number is a combination of kiln name, been considered the most precise and direct to measure collection site and serial number, such as TZH-LSK-1, the fring temperature of ancient ceramics to date [18]. in which TZH is the abbreviation of Tengxian Zhonghe In 1959, Terrisse frst introduced this method to the feld kiln, and LSK is the abbreviation of Lishankou, the col- of archaeology on the fring temperatures study [19]. In lection site. LDY is the abbreviation of Lingdong kiln Y1. 1963, Roberts explained in detail the structure of the thermal dilatometer, the specifc operation and analysis Sample preparation methods of temperature measurement [20]. In the 1960s, Te sample preparation sequence is as follows: clean- Tite proposed the theoretical hypothesis of this method ing drying photographing and recording cut- [21] and then used it to determine the fring tempera- → → → ting → grinding the end and bottom surfaces. Te sample ture of ancient ceramics from diferent periods, which was further cut into rod-shaped rectangular pieces with had been found in Turkey, Iraq, Nigeria, England, China, a length of 25 mm and a width of 3–5 mm. In order to and other countries [22]. In 2012, Pee et al. found that the ensure that the pushrod, gasket, and samples expand or variation in particle size for raw materials could lead to contract in the same straight line during the heating pro- diferent shrinkage rates and changing starting tempera- cess, the two end faces of the sample should be absolutely ture of shrinkage in the reheating process even with the parallel to each other, and the bottom face and two end same original fring temperature [23]. In 2018, Tong and faces should be fat and smooth. Wang systematically studied the method by taking into account multiple factors including temperature rising Method and experiment rate, material type, sintering degree, and determination Method curve selection [24, 25].