In 2021, Chinese mining truck OEM Xiangtan Electric Manufacturing Co Ltd (XEMC), whose mining equipment now comes under Xiangtan Electric Manufacturing Group Heavy Equipment (XEG), as part of a contract with energy company SPIC, converted a 108 t class SF31904 AC drive rigid truck to run on all electric lithium battery power in Huolinhe coal mine, Inner Mongolia. The converted truck became the word’s largest BEV and has a 120 t payload. It began operations in July 2021 and has a large capacity and high performance CATL battery pack with four charging ports capable of charging from a fixed charging station in about 90 mins then is able to work for 7-8 hours. This is done with manual plug in charging, but there is a robotic arm 1,500 kW/h charging project ongoing.
XEMC says a traditional 100 ton truck consumes 1,200-1,600 L of diesel a day and the cost is about $1,480-1,970 for the mine. The power consumption of the electric truck is 3,800-4,300 kW per day, at a cost of $263-298. In addition there are savings from less maintenance work eg changing engine oil, fuel and air filters. Low noise, zero emissions and estimated annual CO2 emissions reduction of 1,500 t. One truck feature is a retard resistance box – while retarding, the system will charge the battery when the bus voltage is in safety range, otherwise using the retard resistance box to consume the retard power.
Jimmy Ji, Director Marketing & Sales, told IM earlier this year that XEG has two orders for the electric truck – one for trucks to be leased in China for a zinc mine in Yunnan Province. That is for two units which were then delivered in August 2022. But a second order is from a Brazilian company Grupo AIZ, initially for two trucks but with a further 10 planned – it has a subsidiary AIZM based in São José dos Pinhais in Parana state specialising in customised new technology solutions in mining and construction including remote control and electric machines, with equipment offered for rental with or without operators.
Ji in August 2022 said that the first two have been completed and have just recently completed factory testing. During the test runs, the company says the truck drove smoothly, operates easily, responds sensitively, while noise is greatly reduced. It is understood that the Brazilian trucks will also be retrofitted for autonomy as well. The two trucks for Brazil are set to be shipped in September 2022.
There is an additional new project with a Chinese mining company to look at building a 220 t electric truck which involves higher voltage charging so there is work to be done on the charging station connectors. Again this truck will be based on retrofit of an existing diesel-electric drive truck. XEMC/XEG and two partners (telecomms/5G group Datang and Huolinhe mine owner, energy group SPIC) also recently formed a new company called Igreencle to focus on green mining trucks and other electric mining equipment. Igreencle will be fulfilling the order for the next 10 Brazil trucks following these first two.
Finally, what about the relatively large number of electric wide body trucks, mainly with 50 or 60 t capacity, now running in China from Tonly, Liugong, Zoomlion, LGMG, Sany, Weichai and others? Ji said these trucks are not operating around the clock and their chassis design means they can only accommodate small battery packs – they are simply using a swapping strategy with the batteries needing changed every two to three hours of running.
