Kiln Sites Research Articles

New chronology evidence of prehistoric human activities indicated by pottery luminescence dating in the humid subtropical mountains of South China

The age of prehistoric human sites serves as a fundamental basis for studying the relationship between human activities and landscape changes in the humid subtropical mountains of South China. The presence of pottery in these archaeological sites is widespread and offers a valuable resource for precise dating purposes. The Longtoushan (LTS) site, located in the northern mountains of Fujian Province, contains a rich variety of pottery types from various periods, representing a rare multi-period stratigraphic overlap in this area and playing a crucial role in constructing the cultural sequence and lineage of prehistoric and ancient times in this region. In this study, we employed thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques to establish the age of pottery samples collected from the LTS site situated in the upper Minjiang River region of southeast China for the first time, while also comparing our findings with other dating methods to construct a chronological framework for the site. The results showed that: (1) The samples analyzed in this study can be classified according to the peak strength of 325 °C TL signal at natural and regenerative doses of quartz. Samples with weak TL signal at 325 °C (type II samples) showed high recuperation and equivalent dose underestimation at a low preheat temperature (220 °C) in OSL test. (2) Conventional SAR procedures employed for type I samples are not suitable for type II samples. Type II samples require additional OSL stimulation towards the end of the cycle and an extended stimulation duration. (3) The application of various dating methods has revealed that the LTS site represents a long-term settlement in the humid subtropical mountains of South China, commencing around 4.6–4.4 thousand years ago (ka). Specifically, the dating of pottery pieces from kiln sites and tombs in the late Neolithic period provides a specific temporal reference for further understanding of prehistoric human culture and production behavior in the humid mountains of Fujian.

분청사기 가마의 연대에 대한 고고지자기학적 연구

Baked earth samples were collected from 15 kilns at 9 sites among the surveyed Buncheong kiln sites. Afterwards, archaeomagnetic analysis was conducted to estimate the age of the kilns. Except for one kiln, reliable data with an error range of about 10 to 20 years were obtained. Since the margin of error is relatively narrow, the time difference between the kilns is not expected to be large, but the relative order of the Buncheong kilns was organized through the date of archaeomagnetic measurement data in this paper. The range of dates established based on archaeomagnetic measurements is from 1340 to 1410 (the early 14th to mid-15th centuries, including the error range), which is older than estimates from the late 14th to mid-15th centuries (about 1390 to 1480) based on archaeological investigations. Although some of the kilns showed little difference in archaeomagnetic and archaeological dating, many others were dated to about 50 years earlier than the archaeological survey suggested. In considering the causes of this discrepancy, the possibility of raising archaeological dating estimates by about 50 years and the possibility of age errors that can occur when dating is estimated through the Japanese standard curve were discussed. If the accumulation of archaeomagnetic data on various contemporary baked earth remains and comparison with other natural scientific dating methods are made, the archaeomagnetic data presented in this paper can be used to complete a more detailed Korean archaeomagnetic standard curve of the construction period of the Buncheong kiln.

Firing technology and physicochemical basis for porcelain from the Xing kiln in the late sixth century

AbstractThe rise of porcelain industry in northern China and the subsequent emergence of white porcelain production during the Northern dynasties (386–581 CE) played a pivotal role in shaping the historical trajectory of Chinese ceramics. Xing kiln is one of China's earliest and most representative white porcelain kilns. Herein, we investigated 23 porcelain sherds from the Neiqiu Xing kiln site during the late Northern dynasties and the early Sui dynasty (550–600 CE) from the perspective of firing temperature, firing atmosphere, and microstructure using a dilatometer, X‐ray photoelectron spectroscopy, and scanning electron microscopy. The results show that the early Xing porcelains were fired at high firing temperatures exceeding 1200°C with a reducing flame, and the adjustment of temperature promotes the emergence of early white porcelain. Moreover, the higher firing temperature of early Xing porcelain leads to the dominance of a glassy phase within the glaze, and the high bonding strength of the glaze and body caused by the body–glaze interaction layer formed with dense anorthite crystals. Overall, these findings provide valuable insights into the firing technology in the Xing kiln and even in North China during the late sixth century.

Does century-old biochar affect soil interrill erodibility on cropland soils? A study on pre-industrial kiln sites

Adding biochar to soils is being advocated to mitigate soil erosion. However, given biochar aging and persistency in soils, the effects of biochar on soil in the long-term are important to investigate yet remain largely unknown. The objective was therefore to determine the long-term effect of biochar on interrill erosion on cropland soils. Experiments were conducted using topsoil from three fields of different textures (silt loam, loam and sandy loam). Each field was characterized by the presence of kiln sites containing century-old charcoal used as proxy to investigate the long-term impact of biochar. Aggregate stability was measured using the method of Le Bissonnais (1996), whereas interrill erosion was studied using two successive (24-h apart) rainfall simulation experiments (84 mm h−1, 90 min.). The presence of historical charcoal in kiln sites did not affect soil aggregate stability, irrespective of charcoal-C content or soil type. For the first rainfall simulation only, the century-old charcoal reduced both the final runoff and soil loss rates by, respectively, 15.4 mm h−1 and 12.1 g m−2 h−1 for each percent increase in charcoal-C content. As a result, Meyer’s interrill erodibility decreased with increasing charcoal-C content. However, because the final runoff and soil loss rates decreased to a similar extent with increasing charcoal-C content, Kinnell’s interrill erodibility was unaffected by charcoal-C content. These effects on interrill erosion parameters were independent of soil type and could not be related to changes in soil chemical properties. The measured reduction in runoff and soil loss were attributed to delayed crust development, which could be related to increasing proportions of clods in the soil samples with increasing charcoal-C content. Further research may be needed to confirm the observed trends and underlying mechanisms over a wider range of soil types.

Three-dimensional deviation analysis and digital visualization of shape change before and after conservation treatment of historic kiln site

The Gangjin Celadon Kiln, after its excavation in 1982, was relocated and restored in 1987 and subjected to primary conservation treatment in 2007. However, many problems such as soil disintegration and cavitation occurred in the kiln until recently. In this study, the shape changes due to the conservation treatment in 2020, which was performed to maintain the original shape of the kiln site, were recorded via three-dimensional (3D) scanning, and numerical analysis was conducted to ensure continuous monitoring and preventive conservation. From the results of this study, the locations and ranges of shape changes before and after the conservation treatment of the kiln site were identified through root-mean-square (RMS) deviation analysis and visualization, and the ranges of reinforcement and soil mulch removal were quantified through the deviations at different points. In particular, the most noticeable shape changes occurring from the conservation treatment on the kiln site with 11.2 m long and 16.7° slope were around 15 mm, and many relative changes of 40 mm or more were also observed. In addition, a reinforcement of approximately 40 mm thickness at the least and a flattening were prominently evident on the floor of the working space; the inside of the combustion chamber was visualized with a reinforcement of at least about 50 mm. Damage caused by natural or artificial factors is expected because two extensive conservation treatments were applied in 2007 and 2020 to the kiln sites. Therefore, short-term monitoring using periodic 3D scanning and time-series data comparisons is necessary for the identification of the point of shape change and the determination of major damaged areas so that a mid- to long-term monitoring plan can be established based on the findings of such observations. In addition, predictive modeling research is mandated to detect areas in the entire kiln site that exhibit a greater probability of deterioration based on the available shape change data.

Pollution indices and correlation of heavy metals contamination in the groundwater around brick kilns in Jammu and Kashmir, India

The present investigation focuses on assessing the water quality of groundwater surrounding brick kilns in the Jammu district of Jammu and Kashmir (J&K). At 43 different brick kiln sites in both north and south regions of Jammu, concentrations of heavy metals were measured using established techniques. The elements zinc, copper, iron, lead, cadmium, nickel, and manganese were analyzed utilizing an Atomic Absorption Spectrophotometer (AAS). The pollution load index value was consistently below unity across all sites, suggesting an absence of pollution and making the water suitable for consumption. The average concentrations, listed in ascending order, were found to be 0.38 mg/L for copper, 0.31 mg/L for zinc, 0.01 mg/L for iron, and 0.09 mg/L for manganese. Notably, concentrations of lead, cadmium, and nickel were found below the detectable levels. Evaluation of contamination factors revealed the sequence Cu > Fe > Zn > Mn, while the geo accumulation index followed the sequence Cu > Fe > Mn > Zn. Comparison of these findings with the established standards of World Health Organization and Bureau of Indian Standards indicated that the recorded ranges were within permissible limits. The study's outcomes suggest that heavy metal emissions from brick kilns may not significantly impact the quality of groundwater. Elevated copper levels found near brick kilns were likely to result from plumbing materials in the study area. Iron and manganese in groundwater seems to have geo-genic origin and not emission-related. This research represents a foundational step in examining groundwater contamination by heavy metals specifically in the neighborhood of brick kilns in Jammu district. It contributes to the establishment of a comprehensive database and serves as a reference point for future studies. Additionally, the study recommends regular monitoring of groundwater to ensure the maintenance of drinking water quality.

Study of the manufacture of high‐fired ceramics from Fujian (China) during the Shang and Zhou dynasties

AbstractIn recent years, some kiln sites from Shang and Zhou dynasties have been excavated in Fujian province in southeastern China, and substantial high‐quality ceramic shards were unearthed. The research conducted by archaeologists indicates that these shards are likely the earliest high‐fired ceramic products in this area, characterised by unique appearance features and are therefore valuable for exploring the development and manufacture of early high‐fired ceramics in Fujian. In this study, we gathered some proto‐celadon and stamped stoneware shards from three kiln sites dating back to the Shang and Western Zhou dynasties. We analysed the chemical composition of the ceramic body and glaze, firing temperature, and mineral phase to investigate the selection of raw materials, firing, and glazing technology of these early ceramic products. The results indicate that the bodies of these high‐fired ceramic shards were made of locally weathered porcelain stone, and the glazes are lime glaze. During the Western Zhou dynasty, the potter utilised different raw materials for proto‐celadon and stamped stoneware, which was not the case during the Shang Dynasty. The firing temperatures of the majority of shards exceeded 1,000°C, and the bodies had been completed phase transformation.

Research on the Distribution and Conservation of Song-Yuan Kiln Sites in Fujian from the Perspective of Heritage Corridor

Research on the Distribution and Conservation of Song-Yuan Kiln Sites in Fujian from the Perspective of Heritage Corridor

In situ charcoal production in Acacia decurrens‐based taungya system improved soil properties and productivity of three agricultural crops in the highlands of Ethiopia

AbstractShort‐term in situ charcoal production‐induced changes in soil properties and crop productivity of acidic soil in Acacia decurrens‐based taungya system were assessed in the Guder watershed of northwestern Ethiopia. Data were collected through field study, pot experiment and interviews with local farmers. The field study involved a survey of 36 paired charcoal production kiln sites and adjacent reference sites in 18 croplands to analyse soil physicochemical properties and productivity of tef (Eragrostis tef), barley (Hordeum vulgare) and wheat (Triticum aestivum). A pot experiment was undertaken with wheat to investigate seed germination and chemical fertilizer needs at charcoal production sites. Local farmers were interviewed for their perceptions and management practices. The production and short‐term presence of charcoal in kiln sites significantly increased sand fraction, pH, organic carbon, available phosphorous, exchangeable Mg2+ and exchangeable K+ compared with the reference sites. Charcoal production practice raised pH by 0.83 units, organic carbon, available P and exchangeable K+ by 40%, 92% and 303%, respectively. Exchangeable acidity and exchangeable Al3+ were lowered by over 80% at kiln sites. Both aboveground biomass and grain yield of tef, barley and wheat were, on average, 135% higher at kiln sites than at the reference sites. Furthermore, crops grown at kiln sites were taller and had greener and larger leaves. Farmers' responses indicated higher crop productivity and reduced inorganic fertilizer application at kiln sites. Results from the pot experiment provided evidence of faster seed germination, enhanced crop productivity and reduced inorganic fertilizer needs in charcoal‐treated soils. The study suggests that the inclusion of charcoal remnants and heating can increase carbon storage, improve soil properties which promote crop productivity and reduce the need for inorganic fertilizer in degraded, acidic agricultural soil.

Biochar modifies soil physical properties mostly through changes in soil structure rather than through its internal porosity

AbstractBesides its carbon sequestration potential, biochar application generally improves soil physical properties, but the magnitude of its impact and the underlying mechanisms remain debated and depend on soil type, biochar application rate, and age. The objective was therefore to determine the effect of biochar application rate and age on physical properties of agricultural soils in a temperate climate. On a silt loam and a sandy loam soils, we compared the physical properties of fresh biochar (1% and 2% w/w) or century‐old biochar (0.5%–1% w/w; 19th‐century kiln sites)‐enriched soil samples with biochar‐free soil samples. Biochar pore network characteristics were determined using helium pycnometry, mercury intrusion porosimetry, scanning electron microscopy observation, and electron dispersive X‐ray spectrometry, whereas location of biochar particles within soil structure was analyzed using optical microscopy observations. Fresh biochar application decreased bulk density by 16.8% and increased saturated water content by 16.0% and macroporosity by 78.8%. These effects were attributed to soil structure improvement rather than to biochar porosity. Soil type and biochar application rate had a limited impact. In the long‐term, biochar effects were mostly nonsignificant, which might result from its fairly low content in kiln sites and from the clogging of its internal porosity by clay particles. Biochar was thus able to improve some soil physical properties in the short‐term, but these effects could no longer be detected in the very long‐term. Further investigating the time rate of change in soil physical properties over several decades following biochar additions to soil would therefore seem particularly relevant.

Study on the coupling effect of chemical color and structural color for Lushan speckle porcelain glaze in the Tang Dynasty (618-907 A.D.)

The Lushan speckle porcelain glaze with charming color fired in the Tang Dynasty (618-907A.D.), is the earliest high-temperature kiln-changed glaze. To clarify its coloring mechanism, the correlation among composition, microstructure and visual appearance of the shards excavated from Lushan kiln site was investigated by XRF, XPS, SEM and TEM. The results indicated that the coloring of sky-blue or moon-white opalescence glaze of the Lushan speckle porcelain was the combination of the chemical color of iron ions and the structural color formed by the coherent scattering of phase-separated droplets. The high atomic ratio of Fe2+/Fe3+ and the small average diameter of phase-separated droplets were beneficial for the formation of the blue opalescence with high color saturation. In addition, it was precisely the presence of black bottom-glaze that incoherent scattering light was greatly absorbed, leading to a higher contrast and a more pronounced structural color of the opalescence glaze.

Accumulation of century-old biochar contributes to carbon storage and stabilization in the subsoil

Soil organic carbon (C) is a key component of the global C budget. As soil organic C turnover rates decrease with depth, agricultural practices favoring deep organic C storage will gain importance as long-term climate change mitigation strategies. In addition, amendment of pyrogenic organic matter (biochar) is considered a promising practice for sequestering C in croplands. However, so far the >30 cm depth soil organic C pool, and subsoil biochar dynamics in particular, has been understudied.To address this, we focused on leftovers from pre-industrial charcoal kilns as a proxy to study the accrual of century-old biochar in the subsoil (30–100 cm) in comparison to adjacent control soil. Using thermal and elemental analyses as well as size and density fractionations (i.e., separating particulate and mineral-associated organic matter), we determined the distribution of pyrogenic organic C within the soil profile and investigated its stabilization in depth. We measured the dissolved organic carbon (DOC) concentrations as well as absorbance and fluorescence properties of dissolved organic matter (DOM) at different depths to characterize the effects of century-old biochar accumulation on the current leaching of DOM.Our results showed that the presence of century-old biochar resulted in an increase of 53.8 ± 25.1 t C ha−1 in 0–100 cm, and 12 % of the pyrogenic organic C was stored in 30–60 cm. No difference in C stocks was observed in 60–100 cm between kiln sites and reference soils. Most of the pyrogenic organic C has been translocated as particulate organic matter, either free or occluded, to subsoils. This led to a change in the dominant fraction of organic matter in the E horizon; in reference soils 64.7 % of the total C was associated with mineral phases as opposed to only 42.3 % in soils enriched with biochar. The thermal analysis of the mineral-associated organic matter revealed that pyrogenic organic C was associated with mineral phases. With depth, DOC concentrations decreased and the relative contribution of microbial byproducts to fluorescent DOM increased. The soils enriched with century-old biochar displayed lower DOC concentrations and more aromatic DOM in the Ap horizon, which suggests biochar dissolution is still an on-going process. Our results suggest that the vertical transfers of century-old biochar mainly occurred as particle leaching in macroporosity and bioturbation but continuous dissolution has also contributed in these fine-textured cropland soils. In conclusion, the association of pyrogenic organic C with mineral phases as well as its migration in subsoil horizons promoted its physical disconnection from abiotic and biotic degrading agents, which likely contribute to the long-term stability of biochar.

Chemical Compositions of Chinese Glazed Tiles from an Imperial Mausoleum of the Liao Dynasty

Glazed tiles are characteristic architectural ceramics traditionally used in ancient Chinese royal buildings. Studies on their chemical compositions have provided valuable information regarding their compositional classifications and the provenances of their raw materials. Existing studies have mainly focused on the Yuan dynasty (1271–1368 AD) or later. Research on earlier ages is limited because of a lack of samples. In this study, we used an energy-dispersive X-ray fluorescence spectrometer to analyze the chemical compositions of 18 glazed tiles unearthed from an imperial mausoleum (the Xinli site) from the Liao dynasty (969–982 AD). The glazes of the tiles had a SiO2–Al2O3–PbO ternary oxidic system and the bodies of the tiles had a SiO2–Al2O3 binary oxidic system. Certain compositional differences were observed among the samples with different types of decorations. Compared with samples from the Yuan dynasty and later periods, the Xinli samples had higher SiO2 and Al2O3 contents and lower PbO and CuO contents in the tile glazes. The tile bodies of the Xinli samples had compositions similar to those of tile bodies from the Qing dynasty (1616–1912 AD). We speculated that the Xinli samples with different decorations came from different kiln sites.

Field Research and Study of Ceramic Wine Vessels in the Song Dynasty: Taking the Jingdezhen kiln as an Example

The purpose of this article is to discuss the social background of wine utensils from Song Dynasty and the aesthetic views unique to the same period. Through field study and research on kiln sites such as Hutian kilns in Jingdezhen, it focuses on analyzing ceramic wine utensils from this period. In the context of the political, economic, cultural, and aesthetic ideas of the Song Dynasty, with the theme of the aesthetic style reflected in Song Dynasty wine utensils, it tries to learn the aesthetic value and functional value of Song Dynasty wine utensils under the background of “emphasizing literature and restraining military” based on the understanding of people's normal lives, social conditions, and religious culture at that time. We hole that it can provide a certain reference for future wine ware research.

Contrasted effects of biochar application on interrill erosion depending on age, application rate and soil type

Besides its carbon sequestration potential, biochar can mitigate soil erosion through improved soil structure. However, the short-term erosion mitigation potential of biochar remains debated, while it is unknown in the long-term. The aim of this study was therefore to determine the impact of biochar application on soil interrill erosion parameters, and to assess whether this impact depends on biochar age and application rate for two different soils. To assess the short-term impact, experiments were performed with topsoil from cultivated silt loam and sandy loam soils enriched with fresh biochar at rates of 1% w/w (13.5 T ha−1) and 2% w/w (27 T ha−1). In the same fields, soil from former kiln sites containing 19th century-old biochar was used to assess the long-term impact. Aggregate stability was measured according to Le Bissonnais (1996). Runoff and soil loss were measured in a flume under simulated rainfall. On the sandy loam soil, old biochar and 2% fresh biochar improved aggregate resistance to slaking. For the same soil, old biochar increased the time to runoff by 55%. For both study sites together, old biochar reduced the final runoff rate by 48%, whereas 2% fresh biochar reduced the final soil loss rate by 39%. Overall, the positive impact of biochar on interrill erosion was clearly more pronounced for the sandy loam soil compared to the silt loam soil. These contrasted results call for further studies across a wider variety of soil types.

Morphological and structural analysis of iron-rich porcelains excavated from the Jian kiln site of Song dynasty.

Iron-rich porcelains generally embrace relatively high iron concentration in the glaze and body, which have an important position in the history of ancient Chinese high-temperature ceramics. The colour and lustre of glaze patterns are closely related to the orientation and order of crystallisation. In this work, three representative types of iron-rich porcelains (persimmon red-glazed sample, oil spot-glazed sample and mirror black-glazed sample) were analysed by portable energy-dispersive X-ray fluorescence (PXRF), optical coherence tomography (OCT), optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and laser Raman spectroscopy (RS) to determine the morphology, chemical composition and microstructure. Results showed that layered structure was observed in both persimmon red and oil spot glazes, however with respective thickness. Besides, iron-enriched crystals mostly precipitated on glaze surface. For the persimmon red sample, multilayer microstructure consisting of three sublayers beneath glaze surface was identified. Crystals and dark red substrates were all made of ε-Fe2 O3 , implying that it was fired at a strong reducing atmosphere. But for the oil spot sample, large-scale leaf-shaped crystals were well characteristic of ε-Fe2 O3 , while small snowflake-shaped crystals were assigned to α-Fe2 O3 , indicating that the firing environment was partially reduced. In addition, there was no crystalline layer existing on surface of mirror black-glazed porcelain, and plain black glaze layer was featured by a glassy matrix. The Jian kiln is a famous ancient folk kiln in the southern China that is currently located in Jianyang county of Fujian province. Its production of black-glazed porcelain began in the Tang dynasty (618-907 AD), became prosperous in the Southern Song dynasty (1127-1279 AD), and declined and ended in the Yuan dynasty (1271-1368 AD). Black-glazed Jian tea bowls were perfect for highlighting the rich white tea decoction. The thick and lustrous black glaze of Jian bowls sometimes were featured by streaked or mottled patterns, usually recognised by 'hare's fur (HF)', 'oil spot (OS)', 'partridge spot (PS)' and so on, which were the crystalline markings of iron oxide precipitated during firing in the dragon kiln. Iron oxide acted as a colorant for black-glazed porcelain and, thus, was called as iron-rich porcelain. The unique patterns originated from local iron-enrichment raw materials and firing process, and the locally iron-enriched areas generated due to the supersaturated crystallisation of different iron oxide in the cooling period. It was generally believed that research studies on the crystallographic nature and growth mechanism of surface crystals would provide help for the manufacturing of ancient Chinese glazes. With this aim, three types of iron-rich porcelain excavated from the Jian kiln were selected to further study the forming cause and growth process of glaze patterns using a series of characterisation methods, like portable energy-dispersive X-ray fluorescence (PXRF), optical coherence tomography (OCT), optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and laser Raman spectroscopy (RS).

Compositional analysis of black-slipped pottery from the Hulushan and Maoershan kiln sites: Insights into social complexity in northern Fujian

When discussing the development of complex societies in China, the northern Fujian region consistently emerges as an area of significance that is often overlooked. Discoveries of kiln clusters discovered at both the Hulushan and Maoershan sites, dating to 4000–3500 BP and noted for their production of black-slipped pottery, combined with the widespread distribution of such pottery across northern Fujian, suggest the potential emergence of specialized production and social complexity in the region. However, there has been rarely systematic discussion on this topic. This paper presents the first compositional analysis of black-slipped pottery from Hulushan and Maoershan using portable X-ray fluorescence (pXRF). Through multivariate statistical analysis of chemical compositional data, this study reveals significant compositional uniformity in the ceramics from both kiln sites, despite being located about 150 km apart, indicating that the potters from Hulushan and Maoershan were likely part of a single, unified community of practice, sharing information and technology on how to make pottery. Our analysis further reveals that the potters at each site deliberately produced two distinct qualities of products, with evidence suggesting that this classification may have reflected social differentiation. Our research highlights the characteristics of specialized production of black-slipped pottery, revealing a unique and often overlooked aspect of the development of social complexity in northern Fujian. Additionally, this research lays the foundation for further investigation into the production and distribution patterns of black-slipped pottery in the surrounding regions in Fujian, Zhejiang, and Jiangxi provinces.

Mössbauer study of the black‐glazed Jian bowl in the Song dynasty

AbstractJian ware, also known as “Tenmoku,” is one of the famous black‐glazed porcelains in China. It was highly coveted in the Song dynasty (960–1279 AD) and was also a tribute to the royal family. The black‐glazed Jian wares are mainly made from iron‐rich clay. In this study, black‐glazed Jian bowl sherds excavated from the Song strata of Jian kiln sites were adopted as test samples. The iron phase and firing techniques of the black‐glazed Jian bowl from the Song dynasty were analyzed and discussed through Mössbauer spectroscopy on the both of body and glaze, together with X‐ray diffraction and scanning electron microscopy. According to the different iron content and the unique iron oxide phase reflected in the Mössbauer spectra, we analyzed the firing atmosphere, temperature, and other conditions of the ancient Jian bowl, as well as the difference of iron phase between the body and the glaze layer due to the collapse of the silicate framework. It provides new ideas for deciphering the firing technology and improving the synthesis of ancient black‐glazed Jian wares.

Corrosion Research on Ru Porcelain Glazes Excavated at Qingliangsi, Baofeng, China

This paper examines two pieces of Ru porcelain glaze excavated from the Qingliangsi kiln site. Compared with the R1 glaze, the R2 glaze was fired at a lower temperature and cooled at a slower rate. The chemical composition, microstructure, and corrosion mechanisms of the two glazes were analyzed by optical microscopy (OM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), micro-Raman spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD). The results show that the corrosion morphology of R1 glaze is mainly the dissolution of a three-dimensionally interconnected calcium (Ca)-rich phase around anorthite, and that of R2 glaze is mainly the dissolution of small droplets distributed in rows, including the dissolution of needle-like wollastonite precipitated by droplet aggregation. In addition, the dissolution of the glass phase and wollastonite crystals forms many white corrosion pits, and the physical and chemical interaction between the corroded glaze and the soil results in the deposition of contaminants that alters the color and texture of the glaze.

Investigating the Impact of Shifting the Brick Kiln Industry from Conventional to Zigzag Technology for a Sustainable Environment

The brick kiln industry is one of the largest and most highly unregulated industrial sectors in developing countries. Most of the kilns use low-quality coal as primary fuel along with small quantities of bagasse, rice husk, and wooden chips. As a result of inefficient methods of combustion in conventional brick kilns, such as fixed chimney Bull’s trench kilns (FCBTKs), harmful pollutants are emitted in high quantities, which ultimately deteriorate the environment and are widely in operation in Pakistan. The most prominent harmful pollutants include carbon dioxide (CO2), carbon monoxide (CO), sulphur dioxide (SO2), black carbon (BC), and particulate matter less than 2.5 microns (PM2.5). Over the years, new technologies have been adopted by developed countries for the reduction of environmental burdens. One of these technologies is induced draught zigzag kilns (IDZKs), or zigzag kilns (ZZKs), technology, which effectively improves the combustion across the path of bricks stacked in a zigzag pattern. For the mass adoption of this technology, environmental assessment and comparison of both technologies is a crucial step. Both types of kiln sites are investigated for the analysis of their emissions and their environmental impact in this work. Carbon mass balance equations are used for the calculation of emission factors. Collected inventory data is then used for the life cycle assessment of both types of kilns using open LCA (version 1.10.3) and the Eco-invent database. According to the study, ZZK technology outperforms FCBTK in all aspects. The analysis of the specific energy consumption (SEC) of fired bricks for each kiln type reveals that ZZKs require 30% less energy than the conventional FCBTK. This implies that ZZKs demand lesser fuel than FCBTKs. The zigzag technology adoption scenario, in particular, can lead to approximately 30% lower CO2 emissions, which can be further reduced by up to 80% when taking into account black carbon (BC) emissions. Additionally, the adoption of zigzag technology can result in a 35% decrease in PM2.5 emissions. The study shows that adopting ZZK technology significantly reduces impact categories, such as particulate matter formation (PMF), photochemical oxidant formation (POF), and terrestrial acidification (TA) by 63%, 93%, and 95%, respectively.