SHANGHAI, Jan 13 (SMM) - Copper inventories in the domestic bonded zone grew 13,300 mt from January 6 to 70,800 mt as of January 13, according to SMM survey. The inventory in the Guangdong bonded zone rose 1,800 mt to 5,600 mt WoW, and that in Shanghai added 11,500 mt to 65,200 mt WoW. Spot imports soared to more than 1,400 yuan/mt over the front-month contract as the SHFE/LME copper price ratio dropped further this week, which seriously suppressed the demand for customs declaration and limited the warrant shipments. Some smelters preferred to export since the export window was wide open, and they moved the goods to the bonded zone warehouses due to factors such as costs and suspension of logistics near the Chinese New Year. Those goods will be delivered after February.