◎Intern reporter Sun Mingyuan
【Technology supports safe production】
In various film and television dramas, sodium cyanide is a "well-known" poison. The average intake of 100-200 mg can cause death, making sodium cyanide a well-deserved "king of poisons".
However, in the gold beneficiation industry, sodium cyanide is also a commonly used beneficiation agent, which has the advantages of simple process and low cost.
However, the wide application of sodium cyanide has brought many safety hazards, and incidents of sodium cyanide poisoning of employees in gold production enterprises have occurred from time to time.
To this end, researchers from Beikuang Chemical Technology (Cangzhou) Co., Ltd. (hereinafter referred to as Beikuang Chemical) have developed a new type of mineral processing agent to replace sodium cyanide in gold production.
"The danger of cyanide is mainly reflected in two aspects: first, during the production process, accidents may occur in the transportation, storage and use of cyanide agents; second, in the post-processing process, cyanide tailings will bring new hidden dangers ” Shang Yanbo, general manager of North Mine Chemical, told the Science and Technology Daily reporter that the danger of tailings should not be underestimated.
At present, my country's gold industry produces about 100 million tons of cyanide tailings every year, and most of them are treated by the method of tailings storage.
The total cyanide content in cyanide tailings is generally about 50 mg per liter. This tailings are hazardous solid wastes, and long-term storage has both potential safety hazards and environmental pollution.
"The dangerous and intractable problem of cyanide tailings has become one of the bottlenecks restricting the development of my country's gold industry." Shang Yanbo said frankly.
In order to solve this problem, North Mining Chemical launched the gold environmental protection mineral processing agent project in 2016 and established a special research and development team.
After 4 years of research and development, in March 2020, BK517 gold environmental protection mineral processing agent and BK518 gold environmental protection leaching agent were developed.
These two reagents can replace the cyanide used in the gold production process, eliminating the safety risks in the process of transportation, storage and use from the source, and also solving the safety and environmental protection hidden dangers in the treatment of cyanide tailings.
Shang Yanbo said that compared with cyanide, these reagents have basically the same leaching rate of gold and silver, and also have the characteristics of short leaching time and convenient transportation management.
After using the new agent, the leaching residue of gold mines is no longer hazardous solid waste, but general solid waste, which not only reduces the harm, but also improves the possibility of further resource utilization.
It can be said that the new drug has both safety benefits, ecological environmental benefits and economic benefits.
At present, this series of agents has been used in the mines of China Gold, Shandong Gold, Zhaoyuan Gold and other enterprises.
The application results show that the total cyanide concentration in the tailings produced by the mines using the new agent is less than 5 mg per liter, which is in line with the "Technical Specifications for the Control of Cyanide Slag Pollution in the Gold Industry" issued by the Ministry of Ecology and Environment in 2018. technical environmental protection requirements.
According to the "China Gold Mining Resources Survey Report" on the official website of the Ministry of Natural Resources, my country is the world's largest producer, consumer and importer of gold.
The gold industry involves a wide area and a large number of employees.
Since it was applied to extract gold and silver in 1887, cyanidation has always been the mainstream in the world gold industry, and the gold produced by cyanidation gold extraction technology has long accounted for more than 80% of the world's total output.
Regarding the "hegemonic" status of the traditional cyanidation method, Shang Yanbo said: "The demand for safety and environmental protection in the gold industry is the general trend, and these are also the regulations of the state. The new chemical has been applied by a number of domestic and foreign enterprises and has achieved good results. In the future, the technology will continue to be upgraded and promoted on a larger scale."
According to the data, Beikuang Chemical is a wholly-owned subsidiary of Mining and Metallurgy Technology Group Co., Ltd., a central enterprise directly under the State-owned Assets Supervision and Administration Commission of the State Council. It is mainly engaged in the research and development, production and sales of green and efficient mining chemicals.
In addition to cyanide substitutes, the company has also developed substitutes for common mining chemicals such as kerosene, diesel, sodium sulfide, nitric acid and other hazardous chemicals, which are used in the beneficiation and production of various minerals.
"The new pharmaceuticals we developed can not only ensure safe production, but also create value for enterprises, and can also generate environmental benefits. The health of workers, the economic benefits of enterprises, and the country's clear water and blue sky are all things we care about. Come to us. Said, these are the real 'gold'." Shang Yanbo said.