1. Gold mine gold in situ smelting
Before the 1970s, gold production was in the initial stage of development. Except for a few mines that began to use the cyanidation process to raise gold, the mines were mainly based on the refining of natural gold and concentrates from sand mines, and the amalgamation method. The mercury paste produced by the gold process is smelted on the spot. The amount of gold in the real estate accounts for only 30% of the total output, and 70% of the gold is recycled by the non-ferrous smelter.
After 1970, the production of gold gradually developed, and the gold extraction process of cyanide was increasingly applied. The mines increased the amount of real estate. In 1985, the output of finished gold products accounted for 70% of the national gold production. Most of the mineral products are produced by in-situ cyanidation and smelting.
Most of the local smelting of mines is carried out by traditional smelting method. Due to the different production processes and materials, the gold content of the combined gold is not the same. The direct delivery banks are not high in gold content or silver-free. In order to improve the quality and economic benefits, the mine has adopted chemical separation and remelting or electrolysis to carry out gold and silver separation and refining. In 1984, Jiaojia Gold Mine experimented with the new technology of water smelting. The cadmium gold mud was electrochlorinated to remove bismuth metal (gold extraction by aqueous solution chlorination and ammonia leaching) to obtain gold-containing grade 99.9% finished gold and silver. 99.9% of silver ingots, copper and lead in gold mud are also recovered at the same time (the tendency to be treated by wet treatment of gold mud). Zhaoyuan Gold Mine successfully developed a Φ1.5×1.8m converter smelting gold mud, which replaced the previous smelting, reduced costs and improved working conditions. This method is widely applied in mines such as Shandong Xincheng Gold Mine, and the effect is good.
2. Recycling of associated gold in non-ferrous smelters
In the production of gold, the recovery of associated gold in polymetallic ores occupies a considerable position. Gold and copper, lead and other non-ferrous metals are selected into the concentrate. In copper and lead smelting, gold and silver are recovered. In order to increase production of gold, some non-ferrous smelters in the country have built precious metal comprehensive recycling workshops. By 1985, there were more than 20 in the country. Apart from Shenyang smelters, there are mainly Zhuzhou, Shanghai, Yunnan, Chongqing, Wuhan and Fuchunjiang. Such as smelting plants and Tianjin, Taiyuan electrolytic copper plant. Among them, the production of companion gold in the three major smelters of Shenye, Shangye and Zhuye accounts for more than 90% of the total output of the national associated gold, which is an important force in China's gold production. The recovery of associated gold in these enterprises is based on the fact that in the process of copper and lead smelting, gold and silver are concentrated in blister copper and crude lead. When electrolytically refining blister copper and crude lead, gold and silver are deposited in the electrolytic anode mud, so it is extracted from the anode mud. Gold and silver are the main ways to recover associated gold and silver.
The treatment process of copper anode mud has been developed rapidly. Through continuous reform and innovation, the traditional fire process is more mature and perfect. The semi-wet process and the whole process are successfully tested and put into production. To make China's smelting technology and equipment level have been greatly improved. Such as the improvement of the fire removal process, the comprehensive recovery of valuable elements, the improvement of the furnace body and the improvement of the vacuum system. There are also the transformation of electrolytic cells, the promotion and application of intermediate frequency furnaces, etc., which have gradually matured and improved the fire smelting process, and improved the technical and economic indicators. Because the fire smelting process has stable technical conditions, mature technology, high comprehensive utilization, strong adaptability to raw materials, large processing capacity, low cost and so on, it is still a smelting plant such as Shenye, Zhuye and Shangye. A universally applied method. Fuchunjiang Smelter, Wuhan Smelter and Chongqing Smelter have achieved remarkable results with the new wet process. Yunnan Smelter and Tianjin Electrolytic Copper Plant have achieved success and put into production through the joint process of metallurgy and smelting, and have also achieved significant economic benefits. The successful test and application of the sulfuric acid slag gold extraction process has also created a new way for China's gold production and full utilization of resources.
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