Method for collaboratively leaching gold in refractory gold ores by virtue of ultrasonic enhancement, chlorination and oxidization

Abstract

The invention discloses a method for collaboratively leaching gold in refractory gold ores by virtue of ultrasonic enhancement, chlorination and oxidization, and belongs to the field of hydrometallurgy. The method comprises the following steps: firstly, crushing gold ores into ore powder, thoroughly mixing the ore powder with sodium hydroxide, sodium hypochlorite and water to obtain ore pulp, introducing air into the ore pulp, and performing ultrasonic enhanced leaching under a stirring condition; periodically adding hydrogen peroxide in the enhanced leaching process. According to the method, at the same time of ultrasonic enhancement, a redox reaction is performed by virtue of the synergistic effect of hydrogen peroxide and sodium hydroxide; the synergistic effect of the hydrogen peroxide and the sodium hydroxide is far better than the independent oxidization effect of each of the hydrogen peroxide and the sodium hydroxide. The ultrasonic enhancement is capable of improving the gold leaching effect while shortening the reaction time, and therefore, the reagent cost can be saved and the gold ore leaching efficiency also can be improved; as long as the method is adopted for leaching, the leaching rate can be above 98%; in addition, the sodium hypochlorite is adopted as a leaching agent for the method and no pressure is caused on the environment; besides, the method is capable of realizing one-step enhanced leaching of the gold ores and shortening the leaching steps.

Description

technical field [0001] The invention relates to a method for synergistically leaching gold from refractory gold ores through ultrasonically enhanced chlorination and oxidation, which belongs to the field of metallurgical industry. Background technique [0002] Due to its excellent performance, gold has also been widely used in modern high-tech industries, such as electronics, communications, aerospace, chemical, medical and other technical fields. With the continuous increase in the mining of gold mineral resources, the reserves of high-grade and easy-to-treat gold mines are increasingly depleted, and refractory gold mines will become an important resource for the gold industry in the future. How to effectively and sustainably develop and utilize refractory gold mines is a technical problem that my country's gold industry urgently needs to solve. [0003] Among the proven gold geological reserves in my country, about 1,000 tons belong to the pyrite / arsenopyrite-wrapped refr...

AI Technical Summary

Problems solved by technology

The polysulfide method leaching agent has poor stability and requires the presence of a stabilizer, and the conditions for recovering gold from the leaching solution are strict

The defect of the organic cyanide method is that the organic cyanide is volatile and toxic, and it is difficult to recover gold from the leachate

The consumption of reagents in the bromination method is high, which will cause interference when analyzed by atomic absorption and inductively coupled plasma emission spectrometry

[0005] The document "Study on Gold and Silver in Silver Concentrate by Ultrasonic Enhanced Leaching (PUL Method)" proposes to use ultrasonic enhanced cyanide leaching of gold and silver. Although this method has greatly improved the traditional cyanide method, it improves the leaching rate and shortens the leaching time. , but pretreatment must be carried out before leaching to convert iron into ferric hydroxide, which increases the leaching process, and cyanide is highly toxic, causing serious environmental pollution

Compared with the traditional leaching method, the leaching method proposed in the document "Principle and Experimental Research on Sodium Hypochlorite One-step Gold Leaching" shortens the leaching process, but lacks strengthening means and strengthening oxidants, resulting in a low leaching rate of less than 90%. Meet production requirements

The leaching method proposed in the document "Fast and Effective Gold Leaching from a Desulfurized Gold Ore Using Acidic Sodium Chlorate Solution at Low Temperature" improves the leaching rate of gold, which has advantages compared with traditional methods, but it must be roasted before leaching, not only Produce waste gas to pollute the environment, and increase the process, delay the process time

In general, although the various leaching methods reported by the predecessors have advantages, they also have their own disadvantages. Either the leaching agent used is toxic, pollutes the environment, or lacks strengthening means and strengthening oxidants, making the leaching The rate is low, or the process is relatively long

Some researchers have reported the use of ultrasonic-strengthened thiourea leaching of gold ore, but the price of the leaching agent in this method is high, the dosage is large, uneconomical, and thiourea may cause cancer, and the mechanism is insufficiently understood

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