Chinese mining companies adopt new geothermal technologies to cut carbon emissions

Iron tailings, traditionally an industrial waste, can now play a role in environmental protection.

In northeast China’s Jilin Province, more than 70 hectares of saline-alkali soil have been transformed into fertile land that can produce 7,500 kg of rice per hectare with the help of iron tailings.

“We make use of the unique physical and chemical characteristics of iron tailings to improve the soil quality,” said Xiong Hongqi, deputy general manager of Ansteel Mining Co., Ltd.

Many mining companies shared their experiences of carbon emission reduction at the 23rd China Mining Conference and Exhibition that concluded Saturday in north China’s Tianjin Municipality.

A drilling rig with a platform of about 10 square meters was among the exhibits that caught the attention of visitors. Compared with traditional drilling rigs that come with a platform of over 100 square meters, this unique rig is small in size and environmentally friendly.

“Drilling rigs with smaller platforms cause less damage to vegetation when used for work on the ground. Besides, it is convenient to transport for mineral exploration and no road construction is required,” said Zheng Bo, vice general manager of EGR(Zhuhai) Special Drilling Equipment.

To cut carbon emissions, some companies have focused on the exploration of new energy. China Energy Chemistry Lvneng Green Energy Technology Co., Ltd. made efforts to use geothermal water for winter heating.

Unlike traditional geothermal heating technology that extracts geothermal water from 200 meters underground, the technology used by the company injects water into a U-shaped closed butt well with a vertical depth of about 2,500 meters and takes underground heat.

“We don’t extract geothermal water from underground because it is not good for the groundwater environment. We inject pipe water into the U-shaped well to obtain underground heat,” said Zhang Jing, an engineer with the company.

Besides, many companies have built solar power, wind power and hydro-power plants in mines to push forward the development of new energy.

According to the 2021 China Mineral Resources released by China’s Ministry of Natural Resources, based on remote sensing monitoring, statistical data shows that approximately 41,600 hectares of mining sites were newly rehabilitated across the country in 2020.

Chen Jinghe, executive director of Zijin Mining, said that carbon emission reduction is a global trend that brings both opportunities and challenges for the mining industry. Major technological breakthroughs are an inevitable requirement for cutting carbon emissions.

SOURCE: Xinhua , Oct. 25, 2021

China Leads in Geothermal Heat Capacity, but Power Generation Lags, Study Finds
Xiongxian geothermal heating installation, Hebei Province, China 

About geothermal energy

Installed capacity of China’s geothermal heat pumps reached 20,000 megawatts by the end of 2018 to rank first in the world. Its primary uses have been in heating and aquaculture, with a lesser portion going to generate power. China’s geothermal electricity capacity in 2018 was 27.28 MW, ranking it 18th in the world.

Geothermal resources provide green, low-carbon, and renewable clean energy, with abundant reserves and massive potential for application. The in-depth analysis of geothermal resources in China, including their distribution and breakdown by shallow, hydrothermal, and hot dry rock (HDR) resources, is made in a recent study by team of Chinese scientists from the China University of Mining and Technology, Beijing, China.

Using the recent economic reports and state-of-the-art technological solutions, this survey outlines the latest trends in the geothermal power generation in China. The application of geothermal power generation in China is still at an early stage, with the total installed capacity of 27.78 MW.

Geothermal power generation technologies, such as dry steam technology, flash technology, binary cycle technology, and enhanced geothermal system (EGS), are discussed in the attached report and linked to their lucrative implementation sites. In particular, Tibet’s Yangbajing is considered to be the most lucrative site for the EGS pilot project.

The comparative analysis of low-cost/large-scale geothermal power generation technologies, such as low- to medium-temperature one, solar-geothermal hybrid one, and geothermal power generation in mines, was made, whose results strongly indicated the EGS technical and economical advantages.

The concentration of 96% of China’s population in the area to the east of Hu line affects the perspectives of high-cost geothermal projects and has to be accounted in the comprehensive analysis of available data. Based on the revealed trends of geothermal resources’ development in China, the research team strongly recommended the comprehensive incorporation of geothermal energy generation into China’s national energy and climate improvement plans, the rapid implementation of HDR technology, as well as comprehensive adaptation of the geothermal-related projects to the local conditions/biased distribution of power consumers and state-of-the-art challenges of power consumption.

Read the full research report: Geothermal power generation in China: Status and prospects, in Energy Science and Engineering, Volume7, Issue5, October 2019.

at the following link