Chihong’s Green Transformation Model
By staff reporter AN XINZHU
In May 2013, Yunnan Chihong Zinc and Germanium Co., Ltd. (Chihong Zn&Ge) bought 51 percent of the shares of two Bolivian mining companies and undertook a month-long evaluation of the mines’ local environments. La Razón newspaper, which has the biggest circulation in Bolivia, reported Chihong’s acquisition with the headline “China assesses the environmental impact of their investments,” claiming that the mining projects were the first to pass the test in Bolivia. The report commended Chihong’s respect for local religion, cultural tradition and folk customs, and environmental protection consciousness.
Chihong Zn&Ge has been on a course of change for many years, and has made headway in such fields as metallurgy technology, product innovation, energy conservation and emissions reduction. When Chihong explores its opportunities for international investment – in Canada, Australia and Latin America – it spotlights clean production.
Based in Qujing, Yunnan Province, Chihong Zn&Ge is the largest nonferrous metal processing company in the region, and a typical resource-based enterprise. But Yunnan, the frontier province in southwestern China, lags economically far behind the Yangtze River and Pearl River deltas, centered in Shanghai and Guangzhou, respectively.
Transformation, No Easy Feat
Qujing in eastern Yunnan has the second largest industrial economic aggregate in the province, and is an important industrial base by virtue of its rich coal resources.
Under the pressure of aggravated pollution and the demand for sustainable growth, both local governments and enterprises now face the pressing task of economic restructuring and industrial upgrading, and a slew of policies have been promulgated in this regard. This trend has a huge impact on Qujing’s industrial sector, which is resource-based and dominated by heavy chemical industry and primary processing. Consequently, the local economy increasingly feels the pinch of inherent problems like lack of structural diversity, short industrial chain, low added value and weak market competitiveness.
Looking back at China’s development, there have been altogether three significant industrial upgrades and economic transformations in the 32 years since commencement of China’s reform and opening-up to 2010. During this period the world proportion of Chinese manufacturing added value grew from 3.15 percent to 19.8 percent. To regional governments and enterprises, the pace and quality of industrial transformation are decisive to the competitiveness of the regional economy and the prospect of their future growth.
Therefore, transformation and upgrading are imperative for the steady and constant development of Qujing’s industry.
Established in 1951, Chihong Zn&Ge was the first enterprise in China to successfully extract the element germanium from lead-zinc oxide ores. In the wake of the financial crisis in 2008, Chihong, along with other resource-based enterprises in Qujing, had to face the challenge of transformation.
In June 2011, in order to improve productivity, Chihong overcame diverse difficulties and closed its 46-year-old smelter located in Huize County.
Meanwhile, to solve the problems of heavy metal pollution, Chihong Zn&Ge cooperated with the Institute of Geographic Sciences and Natural Resources Research under the Chinese Academy of Sciences (CAS) over development and application of soil renovation technologies. It cultivated hyperaccumulators, special plants capable of growing in soils with high concentrations of metals in mining areas to improve and restore the environment of ore bodies.
Green Upgrading
To realize transformation, Chihong Zn&Ge has carried out a series of reforms including extending the industrial chain, raising added value and developing high-end end products.
Specifically, in the processing of metal germanium, Chihong made forays into the development and manufacture of aviation solar germanium wafers and germanium components for detectors. Such ventures accelerated the diversity and technological level of Chihong’s germanium products. As for the company’s other core product, zinc, Chihong has expanded from the traditional manufacturing of zinc plate to more than 40 types of zinc alloy with higher added value. They are sold to steel companies all over China.
Chihong’s refining and smelting process produces slag, which the company recycles to extract valuable metals – gold, silver, germanium, cadmium, copper and bismuth.
Chihong Zn&Ge refines 400,000 tons of lead and zinc annually, and recycles 150 kg of gold, 180 tons of silver, 30 tons of germanium, 800 tons of cadmium, and more than 1,000 tons of other metals including bismuth and antimony. Advanced equipment, environmental responsibilities and cutting-edge technology help Chihong get ahead in the competition among domestic industrial peers.
In its strenuous energy conservation and emissions reduction efforts and maximum use of resources, Chihong Zn&Ge maintains a leading place in the sector in terms of products’ energy consumption index. In 2013, the overall energy consumption of Chihong was equivalent to 160,000 tons of standard coal, 42.9 percent lower than in 2010.
Chihong’s overall energy consumption of lead refinement from January to May 2014 was 9.5 percent below the upper level of the national standard; the consumption of zinc refinement meets the upper level of the national standard; and coke consumption in crude lead processing also leads the field.
Development of Circular Economy
Located in the Qujing Economic and Technological Development Zone, Chihong’s Qujing factory, opened in 2003, has a tranquil setting.
The key to success for a resource-based enterprise like Chihong is the circular economy development mode of resource-product-renewable resource -renewable product. This mode controls the consumption of resources and the discharge of waste to the greatest possible extent.
The enterprise also spotlights recycling of industrial waste water, slag and heat. Even sewage and rainwater are recycled in the factory.
As much as 98 percent of sulfur dioxide (SO2) produced in the refining process is recycled and re-used as sulfuric acid and ammonium sulfate. Thus, the general utilization of SO2 is as high as 99 percent. Consequently, the emission of SO2 is reduced by 50,000 tons annually, far exceeding the national environmental standard.
To recycle steam energy, Chihong Zn&Ge has installed four waste heat recovery boilers at the Qujing plant. Firstly, saturated steam is used for electricity generation; then, low-pressure steam provides heat energy for manufacturing and facilities. Such technology not only satisfies the demands of production and daily life, but also improves the utilization of heat energy and reduces energy consumption during the refining process.
The innovative rainwater recycling technology developed by Chihong Zn&Ge has been promoted among lead-zinc refining factories nationwide. The company designed three types of disposal system for industrial waste, household sewage and rainwater respectively. Rainwater is collected and reused in the production process directly after sedimentation, hence reducing the amount of water drained outside the factory and the heavy metals that may be flushed away in it. Some drainage is to be expected only in the case of heavy rainfall. Treatment of household sewage saves the company another 65,000 tons of water annually.
As for the waste materials that cannot be reused or recycled for now, Chihong Zn&Ge has invented the paste backfilling technology, whereby mine tailings are mixed with appropriate proportions of gravel and slag to fill mined-out areas.
One significant advantage of paste backfilling is its role in the prevention of environmental disasters such as subsidence, fracturing and landslides. The techniques employed at Chihong are regarded as the most advanced in backfilling technology for ore mines, and a model for mining industries globally. The case has been selected as a key demonstrational practical environmental technology project by the China Association of Environmental Protection Industry.
