to cover with a hardened layerpipes crusted with mineral deposits
pipes crusted with mineral deposits
caked, encrusted(also incrusted), rimed
besmeared, coated, smeared, spreadcovered, daubedcoagulated, congealed, hardened
英语同义词词典收录了63618条英语词条，基本涵盖了全部常用同义词或反义词的辨析及翻译，是英语学习的有利工具。