Experiment of Gold and Silver Extraction from Cyanide Tailings by Melting Chlorination
Sun Yanwen,
Yuan Chaoxin,
Guo Chihao,
Li Dajiang,
Li Yibin,
Mu Liangzhao
Issue:
Volume 6, Issue 2, June 2021
Pages:
20-23
Received:
21 April 2021
Accepted:
6 May 2021
Published:
14 May 2021
Abstract: Cyanide tailings produced in gold smelting process contain a large number of heavy metals and cyanides, which are more and more harmful to the environment. In order to reduce environmental pollution, valuable metals from cyanide tailings are recovered. The amount of calcium chloride, chlorination time, the way of adding calcium chloride and other factors on the influence of gold and silver extraction by chlorination were studied by using the raw material of cyanide tailings with melting chlorination process in this paper, and how to reduce the melting chlorination temperature was explored, and a comprehensive experiment was carried out under the best conditions. The results showed that when the chlorination temperature is 1500°C, the chlorination time is 1 h, and the addition amount of CaCl2 is 7%, the volatilization rate of gold is 85.38%, the content of gold in slag is 1.83 g/t, the volatilization rate of silver is 77.36%, and the content of silver in slag is 4.12 g/t; when the chlorination temperature is 1500°C, 7% CaCl2 is added, and the chlorination time is 15 min, the volatilization rate of gold is 87.78%, the content of gold in slag is 1.23 g/t, the volatilization rate of silver is 59.40%, and the content of silver in slag is 7.39 g/t; the addition of 5% CaO can change the slag type, reduce the chlorination temperature by 50~100°C, increase the volatilization rate of gold and silver slightly, and decrease the content of gold and silver in slag; when CaCl2 is added in five times, the volatilization rate of gold increases to 95.53%, the content of gold in slag decreases to 0.56g/t, the volatilization rate of silver increases to 77.80%, and the content of silver in slag decreases to 4.04 g/t; 7% CaCl2 was added in five times, and the melting chlorination time was 15 min. the amount of CaO was 5%, and the melting chlorination temperature was 1450°C, the gold volatilization rate is 95.69%, and the gold content of slag is 0.54 g/t, the silver volatilization rate is 77.06% and the silver content of slag is 4.20 g/t.
Abstract: Cyanide tailings produced in gold smelting process contain a large number of heavy metals and cyanides, which are more and more harmful to the environment. In order to reduce environmental pollution, valuable metals from cyanide tailings are recovered. The amount of calcium chloride, chlorination time, the way of adding calcium chloride and other f...
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Design Principles and Improvement of the Evaluation Methods for the Shatter Strength of Metallurgical Materials
Wendan Tang,
Junxue Zhao,
Liang Niu,
Lv Zhao,
Tingliang Zhang
Issue:
Volume 6, Issue 2, June 2021
Pages:
24-32
Received:
6 April 2021
Accepted:
15 May 2021
Published:
31 May 2021
Abstract: Shatter strength refers to the ability of materials to resist collisions and impacts and is an important property of metallurgical minerals. Although the current methods differ in terms of the testing equipment, implementation steps and data processing methods, these approaches are nearly identical in principle. However, the current methods are not sufficiently accurate, which makes it difficult to objectively evaluate shatter strength. Therefore, new and more accurate methods are needed. In this paper, a variety of current methods were discussed, design principles were summarized, and new methods were proposed that consider the influence of the degree of rupture and drop time when cracks are generated on the results of shatter strength tests. Based on the new design principles, new parameters such as the crack size index, number of fragments, and total mass of the fragments were added to the evaluation formula. In addition, the test processes were optimized. Then, a batch of lead-containing pellets were evaluated by the new methods. The results obtained in this test show that, compared with the old methods, the new methods can more accurately and objectively evaluate shatter strength and reflect product quality. Users can also design new methods for all kinds of brittle materials according to these principles. However, the new method is more complex than the old methods and needs to consider a greater number of factors. At present, there is no effective means to address the workload. With the development of artificial intelligence and automation devices, new design principles and methods will be more widely utilized.
Abstract: Shatter strength refers to the ability of materials to resist collisions and impacts and is an important property of metallurgical minerals. Although the current methods differ in terms of the testing equipment, implementation steps and data processing methods, these approaches are nearly identical in principle. However, the current methods are not...
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