干旱区生态环境知识资源中心(Arid): Conservation of the Shaft #1 Headgear at the Tsumeb Mine, Namibia: Corrosion Protection

Arid

DOI	10.1080/00393630.2021.2004007
	Conservation of the Shaft #1 Headgear at the Tsumeb Mine, Namibia: Corrosion Protection
	Boellinghaus, Thomas; Wentland, Eva; Jassmann, Ronny; Keller, Ruth; Wolfrum, Anne
通讯作者	Boellinghaus, T (corresponding author), Unter Eichen 87, D-12205 Berlin, Germany.
来源期刊	STUDIES IN CONSERVATION
ISSN	0039-3630
EISSN	2047-0584
出版年	2021-12
英文摘要	The Tsumeb Mine in Namibia represents one of the best-preserved mining sites in the world and is rapidly gaining cross-disciplinary interest among cultural and engineering scientists. Most of the open pit and the shaft mining equipment are still in place, including the ore processing units and the local power plant. The mining area thus deserves recognition as an industrial world heritage site, especially due to the rarity of such locations on the African continent. The Shaft #1 headgear, built in 1924, represents one of the oldest known riveted steel headgears of the Promnitz design worldwide. In contrast to similar steel structures located in the northern hemisphere, it has been exposed to a different rural semi-arid climate since it is located in the Otavi Mountain Land, characterized by semi-annual change of rainy and dry seasons. Parts of the Shaft #1 headgear have remained largely untouched for more than 70 years. Besides its outstanding heritage value, it thus also represents an interesting object for studying the composition of corrosion layers formed on mild steel surfaces when exposed to continental and industrial mining atmospheres. To find a suitable transparent corrosion prevention coating, various on-site coating samples were evaluated after 11 months of outdoor exposure, including Owatrol Oil (R), which is based on natural oil and alkyd resin with strong wicking potential. The substance is frequently applied for the conservation of single components but is not yet widely used on large steel structures in the field of industrial heritage conservation. However, it represented the most stable anti-corrosion coating under the local atmospheric conditions in the on-site tests. Thus, the suitability of Owatrol Oil (R) as a transparent coating for corrosion protection of riveted mild steel structures in such climates was further investigated as a more recent approach for the conservation of large steel structures. Since the protective coatings are exposed to strong UV radiation in the local climate, the addition of a specific UV stabilizer mixture was also tested. For such laboratory tests, two mild steel samples were taken. The first one originated from a diagonal strut of the 1920s and the second one from a handrail mounted in the early 1960s. Using corresponding high-resolution scanning electron microscopy (HR-SEM) and energy-dispersive X-ray spectroscopy (EDX) it was found that the corrosion layers are predominantly composed of lepidocrocite and goethite. A weathering program simulating the specific environmental conditions at Tsumeb in a UV climate chamber was developed and the corrosion resistance of the mild steel surface was subsequently evaluated by potentiodynamic measurements. Such tests proved to be a fast and reliable procedure for ranking the corrosion resistance of the old mild steels. It was found that the long-term corrosion layers already provide significant protection against further corrosion in the simulated environment. However, the study also showed that this can be further improved by the application of the Owatrol Oil (R) as a protective coating that also seals crevices. The addition of the UV stabilizers, however, led to a significant deterioration in corrosion protection, even in comparison to that of the uncoated long-term corrosion layers on the surface. Regular overcoating seems more advisable for the long-term preservation of the Shaft #1 headgear than modifying the Owatrol Oil (R) coating with the tested UV-stabilizing additives.
英文关键词	Mining head gear mild steels chemical composition characterization of corrosion layers alkyd resin-based coating UV-blocker addition weathering tests potentiodynamic measurements
类型	Article ; Early Access
语种	英语
开放获取类型	hybrid
收录类别	SCI-E ; AHCI
WOS记录号	WOS:000732574300001
WOS关键词	ATMOSPHERIC CORROSION ; WEATHERING STEELS ; RUST LAYERS
WOS类目	Archaeology ; Art ; Chemistry, Applied ; Chemistry, Analytical ; Spectroscopy
WOS研究方向	Archaeology ; Art ; Chemistry ; Spectroscopy
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/374738
作者单位	[Boellinghaus, Thomas; Wentland, Eva; Wolfrum, Anne] BAM Fed Inst Mat Res & Testing, Dept Component Safety, Berlin, Germany; [Wentland, Eva; Jassmann, Ronny; Keller, Ruth] Univ Appl Sci HTW, Conservat Modern Mat & Ind Heritage, Berlin, Germany
推荐引用方式 GB/T 7714	Boellinghaus, Thomas,Wentland, Eva,Jassmann, Ronny,et al. Conservation of the Shaft #1 Headgear at the Tsumeb Mine, Namibia: Corrosion Protection[J],2021.
APA	Boellinghaus, Thomas,Wentland, Eva,Jassmann, Ronny,Keller, Ruth,&Wolfrum, Anne.(2021).Conservation of the Shaft #1 Headgear at the Tsumeb Mine, Namibia: Corrosion Protection.STUDIES IN CONSERVATION.
MLA	Boellinghaus, Thomas,et al."Conservation of the Shaft #1 Headgear at the Tsumeb Mine, Namibia: Corrosion Protection".STUDIES IN CONSERVATION (2021).