Abstract: With the rapid development of the economy, the demand for gold ore is increasing day by day, which makes the beneficiation of gold ore more and more strict. In this paper, through the experiment of beneficiation of fine-grained gold ore, the best conditions of beneficiation process are obtained to meet the demand of gold.
The production and reserves of gold are an important symbol to measure the comprehensive strength of a country. Gold plays an important role in the world economy. Due to the characteristics of gold that will not depreciate, it greatly promotes the demand for gold. Therefore, the gold ore beneficiation technology is put forward Great challenge.
1. Mineral processing test of fine-grained gold ore
1.1 Properties of ore
Extracting gold from sulfur-containing fine-grained disseminated gold ore is one of the important sources of gold in my country at present. The distribution of gold minerals in this ore is fine and difficult to separate, and the outer layer has sulfides such as pyrite and arsenite. Therefore, it is difficult for conventional gold leaching agents to extract gold from it. Studies have shown that leaching gold with cyanide after chemical pretreatment to enrich gold-loaded sulfide ores is currently the most effective method for treating sulfur-containing fine-grained disseminated gold ores.
1.2 Mineral dressing test
(1) Principle of the test. The gold in the fine-grained gold ore is mainly embedded in the sulfide minerals with fine-grained gold. Pyrite has good buoyancy, and the gold in the pyrite is enriched by flotation. The content of silicate in the ore is high, so sodium carbonate is used as pH regulator, sodium silicate is used as gangue inhibitor, copper sulfate is used as sulfide ore activator, butyl ammonium black drug and butyl xanthate are used as collectors agent for flotation tests.
(2) Test samples. Fine-grained gold ore mainly contains metal ores such as pyrite and hematite and gangue minerals such as quartz, dolomite and hydromica. Except for gold, elements such as copper and zinc in the ore have no comprehensive recycling value. In this test, the fine-grained gold ore is mainly used as the sample to analyze the recovery rate of gold.
(3) Test agents and equipment. The reagents required in the test are: sodium carbonate, sodium silicate, copper sulfate, butylamine black medicine, butyl xanthate, tap water, 2# oil. The equipment required for the test includes: conical ball mill grinding, series single tank, series hanging tank flotation machines.
(4) Sample test:Grinding fineness test. Before flotation, the ore is ground to separate the minerals in the ore, and the ore is ground to the most suitable particle size for flotation, which can not only separate the fine-grained sulfide ore to the greatest extent, but also make the gangue slime The degree of influence is minimized, and the flotation efficiency of fine-grained sulfide ores is increased. The test shows that the gold recovery rate increases gradually with the increase of the grinding fineness. When the grinding fineness exceeds 0.074mm90%, the gold recovery rate will decrease. Therefore, it can be determined that the grinding fineness of fine-grained gold ore is 0.074mm90%.
Drug dosage test. During flotation, the amount of reagents has a great impact on the flotation results. The amount of pH regulators, activators, collectors and gangue inhibitors should be controlled within a certain range to ensure the maximum flotation effect . The test shows that when the grinding fineness is 0.074mm90%, the optimal dosage of sodium carbonate regulator is 6000g/t, the optimal dosage of copper sulfate activator is 200g/t, and the optimal dosage of collector is Amine black drug 40g/t, butyl xanthate 80g/t, the optimal dosage of sodium silicate is 500g/t, under this dosage, the gold recovery rate is 82.5%.
(5) Test results. The test shows that the best conditions for the flotation of fine-grained gold ore are: the grinding particle size is 0.074mm90%, the dosage of sodium carbonate is 6000g/t, the dosage of butyl xanthate is 80g/t, and the dosage of butyl ammonium black medicine is 40g/t , the dosage of copper sulfate is 200g/t, and the dosage of sodium silicate is 500g/t. Under this condition, the gold in the fine-grained gold ore can be recovered and enriched by flotation to increase the recovery rate of gold.
2. Present situation of fine-grained gold ore flotation agents
At present, copper sulfate is the most widely used activator for fine-grained gold ore in my country, while sulfur dioxide is widely used as an activator for ore flotation in foreign countries. This activator can dissolve iron hydroxide on the surface of pyrite, arsenite and other ores. Thin film, forming copper sulfide film, increases the buoyancy of ore.
Mineral fine sludge can destroy the selectivity in the flotation process and reduce the recovery rate of gold, so it is very important to choose the inhibitor of fine-grained gold ore. At present, sodium silicate is commonly used as an inhibitor of gold mines in my country, and sodium carbonate is used as a pH regulator. These two agents can effectively inhibit copper and zinc elements and reduce gold dissolution caused by copper elements.
The existing collectors in my country include black powder, xanthate and esters. Generally, butyl xanthate and butylamine black powder are used as collectors for fine-grained gold ore. At the same time, my country has also done a lot of research work on new pharmaceuticals, among which the representative achievements are Y-89 series and MAC series. Due to the special molecular structure, Y-89 series has good selectivity and collection ability; MAC series collectors have a good effect on gold recovery rate in copper-gold ore and gold-bearing pyrite.
2.3 Foaming agent
The commonly used foaming agents for fine-grained gold ore in my country include pine oil (2# oil), camphor oil, and alcohol oil, among which 2# oil is the most widely used. 2# oil is a light yellow oily liquid with a density of 0.9-0.91g/cm3. The main component is 伪-terpene alcohol. The composition of 2# oil is relatively stable and suitable for most occasions. It is used in the flotation of gold ore Has excellent performance.
3. Equipment status of fine-grained gold ore
3.1 Grinding equipment
With the rapid development of the economy, modern grinding equipment is gradually developing in the direction of energy saving and high efficiency. As the ore becomes more and more complex, ultra-fine grinding equipment is also receiving more and more attention. The new generation of Nordberg cone crushers in Jiangxi Jinshan Gold Mine not only solves the problems of the original crushing process, but also improves the working efficiency of the equipment and saves energy consumption and materials.
3.2 Flotation equipment
At present, the SF type, SDF type, QF type and other high-efficiency flotation machines developed in my country have been popularized and applied in gold mines. The application of cyclone-static micro-bubble flotation column and flotation machine in gold mine greatly increases the selectivity and recovery rate of flotation, and flotation machine has certain advantages in coarse particle flotation.
4. Present situation of fine-grained gold ore beneficiation process
4.1 Conventional fine-grained gold ore beneficiation process
Conventional fine-grained gold ore is easy to select and separate. Simple mineral processing technology and reagents can guarantee a high recovery rate of gold. At the same time, in order to save energy, conventional mineral processing technology should use more intensive technology to maximize resources. use.
4.2 Complex fine-grained gold ore beneficiation process
According to the survey, my country's refractory gold ore accounts for a quarter of the total ore volume. The gold in this type of ore is particularly fine and the ore components are particularly complicated. For complex fine-grained gold ores, the recovery rate of gold should be enhanced through intensified pretreatment process and combined process.
The enhanced pretreatment process refers to the pretreatment of the ore under the action of various energy fields and microorganisms to expose the wrapped gold and improve the recovery rate of gold. In actual production, methods such as roasting oxidation, biological pre-oxidation, and chemical oxidation are commonly used to pretreat fine-grained gold ore. The test shows that under the optimal conditions of the test, the roasting-cyanidation gold leaching process is adopted for gold ore, and the gold cyanide leaching rate is as high as 92%. This process has the advantages of less investment, simple process, low energy consumption, and no pollution.
With the accumulation of experience in complex gold ore processing by mineral processing technicians, new mineral processing technology has gradually been developed. Using carrier flotation technology, high-efficiency collectors are used to increase the amount of free gold, and finally the recovery rate of gold is improved through flotation. The research and development of new technology not only improves the recovery rate of gold, but also saves more energy, and greatly improves the protection of the environment. While focusing on development, it also pays attention to ecological balance, making the beneficiation process more and more scientific and international .
The beneficiation process of fine-grained gold ore must not only ensure the best flotation conditions, but also select the appropriate flotation equipment and flotation reagents in combination with the actual situation, and adopt a scientific beneficiation process. While improving the recovery rate of gold, attention should be paid to Save resources and protect the environment. With the improvement of my country's comprehensive national strength, my country's international status is getting higher and higher, and the gold reserves and production volume have an important role in my country's future development. Combined with the test and the actual situation, develop a beneficiation technology in line with my country's national conditions, and make contributions to my country's gold industry chain.