Carbon slurry gold tailings recovery gold and silver examples

Yindongpo gold mine was built in 1981 and put into production 100t / d mineral processing plant in 1985 after beneficiation process for the CIP process, increase production capacity to 250t / d. Before the completion of the new tailings pond in 1992, the old tailings pond stocked up to 900,000 tons of recoverable tailings with high gold content, containing about 1665 kg of gold and 25 tons of gold.

In 1996, the ore dressing plant began to use the original 250t/d carbon slurry plant for industrial practice of tailings treatment. The whole mud cyanide carbon pulp gold extraction process was used to recover gold and silver from old tailings. The production process is as follows: the mining of tailings utilizes a simple chain bucket sand mining vessel with a capacity of 250t/d. The tailings are transferred from the sand pump to the 250t/d carbon slurry plant by the sand pump, giving φ1500mm× A closed-length grinding consisting of a 3000mm ball mill and a spiral classifier. The overflow is given to a φ250mm cyclone. The cyclone and the No. 2 (φ1500mm×3000mm) ball mill form a two-stage closed-circuit grinding. The graded overflow is fed into the φ18m concentration tank, concentrated and leached for adsorption, during the leaching adsorption process. In order to expand the processing capacity, the index is further improved, and the vacuum pump is used instead of the vacuum pump to supply oxygen. The gold-loaded rock is produced by the side immersion and side suction process, and the gold is produced after desorption and electrolysis. The process of selecting and smelting is shown in the figure below.

Flow chart of tailings carbon slurry method

After industrial production practice, the main indicators have achieved satisfactory results. The production capacity is above 250t/d, the tailings concentration is about 20%, the fineness is -0.074mm, accounting for about 55%, the double helix graded overflow is -0.074mm, accounting for 75%, and the cyclone graded overflow is -0.074mm. 93%, leaching concentration of 38% to 40%, leaching time of more than 32h, calcium oxide dosage of 3000g / t, sodium cyanide dosage of 1000g / t, five-stage adsorption average bottom rock density of 10g / L. The main indicators are as follows: dip quality: gold 2.83g / t, silver 39g / t, gold leaching rate of 86.5%, silver leaching rate of 48%, gold smelting total recovery rate of 80.4%, total silver smelting recovery rate It is 38.2%.

According to the preliminary investigation of the tailings resources of the old tailings pond, the tailings with a gold grade of more than 2.5g/t are about 380,000 tons, which can be used for 4 to 5 years in the production of carbon pulp plants. According to the practice of industrial production, it can be extracted from tailings. The recovery of gold is 760kg, silver is 5t, and the output value is more than 70 million yuan. At the same time, it is pointed out that due to the low cost of processing tailings, the tailings treated with more than 1g/t are also slightly profitable. It not only increases the gold output, but also reduces the production cost of the enterprise. Therefore, it treats tailings above 1g/t. It is also advantageous.