【Technology】Gold mining process

 1. Mining

Mining is the extraction of economically valuable minerals or other substances from the ground, and all mining sites are mineral-rich deposits. Mining techniques are basically divided into two forms: open pit mining and underground mining. After exploration and feasibility studies are completed, ore is mined from the surface or underground using machinery such as excavators, drills, explosives and trucks.

2. Crushing mining process

The ore mined is very large. At present, the maximum ore particle size of open pit mines is 1000mm1500mm, and the maximum ore particle size of underground mines is 300mm600mm. Due to the close symbiosis of useful minerals and gangue minerals, such large ores cannot be directly separated. To separate them from each other, the ore must be crushed to a certain particle size before the next beneficiation operation.

3. Transportation during mining

Typically, belt conveyors are used to feed bulk ore to primary and secondary crushers, and then feed the crushed ore to vibrating screens to obtain different sizes.

4. Screening of the mining process

The screening process also plays a different role in the gold mining process.

Pre-screening: Before the ore enters a certain stage of the crusher, pre-screening the qualified products that meet the requirements. This process not only prevents the ore from being over-crushed, increases the productivity of the crusher, but also prevents the crusher from clogging.

Inspection and screening: After crushing, screening should be carried out to check the particle size of the crushed products, so that the unqualified extra-large ore particles can be sent back to the crushing operation to be crushed again.

5. Grinding during mining

Crushing is a continuation of the crushing process. Its purpose is to separate most of the useful mineral particles in the ore into monomers and classify them so that the particle size meets the requirements of the classification operation. In general, we support the principle of grinding more and grinding less to save costs.

6. Classification of mining processes

Classification: In the medium, substances are divided into different particle sizes according to different sedimentation rates.

The purpose of classification and screening is to separate the ore particles into different particle sizes, but their working principle and the particle size characteristics of the product are different.

The sieving should be strictly separated according to the sieving size;

Distinguish and classify materials according to the different settling velocities of materials in the medium.

In the grinding process, the qualified materials are usually separated in time by the method of classification, so as to avoid the excessive grinding of the ore and improve the grinding efficiency. Commonly used equipment are spiral classifiers and cyclones.

7. Gold mining process

The gold mining process mainly includes the following methods: cyanidation, flotation, gravity separation and mercury amalgamation.

8. Water treatment during mining

Coarse dewatering is relatively easy. Usually natural drainage is used, that is, natural drainage is drained by the gravity of the water itself. Dewatering of fines typically involves three operations: concentration, filtration and drying. Reclaimed water can be used for some parts of mineral processing operations, or it can be discharged after being treated to standards through a water treatment plant. 

9. Dry stacking of tailings

Concentrating hydrocyclone + high-efficiency deep cone thickener + high-efficiency multi-frequency dewatering screen, so that the final concentration can reach more than 85%, so as to achieve dry accumulation. The tailings are then used for paving, construction, etc.

【Phosphate ore flotation】Phosphate ore beneficiation and flotation reagents

Phosphorus is an important raw material for the production of phosphate fertilizer, yellow phosphorus, phosphoric acid, phosphide and other phosphate products, and is a non-renewable and alternative resource. The reserves of phosphate rock resources in my country are relatively large, but more than 70% of them are low-grade and lean ore, which cannot be industrialized only by the scrubbing process. At present, medium and low-grade phosphate rock resources are mainly used for enrichment, and the flotation effect of phosphate rock depends on the interaction between mineral particles and air bubbles in the water medium, among which flotation reagents are particularly important.

Commonly used flotation processes for phosphate ore beneficiation are: positive flotation, reverse flotation, first positive then reverse flotation, first reverse then positive flotation and double reverse flotation.

1. Positive flotation process of phosphate rock

The process is to grind the phosphate rock until the monomer is dissociated, add water to the slurry to adjust the concentration to a certain concentration, use a specific collector to enrich the useful phosphorus minerals in the foam product, and use a specific agent to inhibit the silicon in the phosphate rock. gangue minerals such as salts and carbonates. Commonly used flotation agents are "S", "L", "sulfonated phenol tar", "F" series of inhibitors.

The process is suitable for siliceous or calcium-siliceous phosphate rock, endogenous apatite, and sedimentary phosphate rock. The technological process is simple, the impurity removal effect is good, and the content of impurities such as Me and Fe can be effectively reduced. But the energy consumption is high and the beneficiation cost is high.

2. Phosphate rock reverse flotation process

In this process, inorganic acid is generally used to adjust the pH of the pulp to a certain range (pH=4.0 to 5.0), and a specific collector is used in a weakly acidic medium to enrich the dolomite into the foam product, and the phosphorus minerals remain in the tank. Commonly used flotation reagents are mainly inorganic acid regulators, modified fatty acid collectors, sulfate modification of fatty acids, or addition of auxiliary agents during their saponification process to improve their water solubility, temperature resistance, collection performance and Optional.

This process is generally suitable for the separation of phosphorus minerals and dolomite gangue minerals, and the exclusion rate of dolomite gangue minerals can reach 70% to 80%. The process does not require heating, and can be carried out at low temperature and normal temperature, which reduces energy consumption and saves costs.

3. Phosphate ore first positive and then reverse flotation process

The process is to first use inorganic alkali to adjust the pulp to weak alkalinity, use a specific collector to enrich the useful phosphorus minerals in the foam product, and leave the silicate gangue minerals in the tank to remove, and the foam is positive flotation. Concentrate, then add inorganic acid to adjust the pulp to weak acidity, positive flotation concentrate (regrinding or non-grinding), and then use collector to enrich carbonate impurities, and leave useful phosphorus minerals in the tank to obtain Reverse flotation concentrate, the main purpose of reverse flotation is to remove MgO impurities in phosphate concentrate. Commonly used are inorganic bases and inorganic acid modifiers, XM-10, water glass and sulfur-phosphorus mixed acid inhibitors.

This process is suitable for the treatment of siliceous phosphate ore, and the grade of phosphate concentrate obtained is higher than that of single positive or reverse flotation, and the combination of positive and negative can effectively improve the processing performance of phosphate concentrate, but the cost of reagents is high, which is not suitable for concentrators. The recycling of water resources has caused great difficulties.

4. Phosphate ore reverse first and then positive flotation process

In this process, the carbonate gangue is first floated with a collector in an acidic medium to obtain an anti-floating concentrate, and then the second-stage grinding is performed until the siliceous gangue is decomposed, and the phosphate rock is floated in an alkaline medium. material to obtain positive floating concentrate.

This process is suitable for low-grade silicon-calcareous collophanites. The process does not require heating and has low energy consumption, but the circulating water needs to be treated separately, which has a great impact on production.

5. Double reverse flotation process of phosphate rock

In this process, inorganic acid is generally used to adjust the pulp to weak acidity, and a part of dolomite gangue is enriched by fatty acid collectors, and then quartz minerals are enriched by fatty amine collectors. Phosphorus minerals in the tank are the final concentrate. Commonly used flotation reagents are inorganic acid modifiers, fatty acid and fatty amine collectors.

This process is mainly suitable for the treatment of mixed phosphate rock with low content of siliceous gangue and carbonate. Especially for the separation of dolomite and quartz-like gangue minerals. It can realize low and normal temperature flotation, with simple process, low energy consumption, simple pharmaceutical system and few types of pharmaceuticals. However, the amine collectors used in this process are cationic collectors, which will produce viscous foam, poor selectivity, and are more sensitive to ore slime. This makes the process more complicated.

List of quartz sand beneficiation equipment

 At present, the common quartz ore beneficiation process is to remove the mineral impurities in the quartz ore by scrubbing, magnetic separation, chute gravity separation, flotation, pickling or a combination of several methods to obtain the particle size and impurities of the quartz ore. The content meets the requirements of high-purity quartz ore. In this process, the commonly used quartz mineral processing equipment mainly includes rod mill, magnetic separator, flotation machine, hindered settler, XCIII hydrocyclone, high-frequency and high-efficiency dewatering screen, inclined plate concentrator, washing tower, desliming Buckets, slurry pumps, etc.

In this article, we will mainly introduce rod mills, magnetic separators, flotation machines, hindered settlers and XCIII hydrocyclones.

01 Rod Mill

In the processing of quartz ore, rod mills are mostly used as grinding equipment, which has good grinding effect, controllable discharge particle size and certain scrubbing function.

◆ Quartz ore grinding discharge particle size is generally between 40-120 mesh. The steel rod of the rod mill is in contact with the material surface, and it is not easy to over-grind. At the same time, it is guaranteed to grind qualified products and exclude unqualified products.

◆ Use rod mill to process quartz ore, which can scrub to a certain extent and help to remove some impurities.

◆ The steel rods and steel rods of the quartz ore rod mill have a certain screening effect on the quartz ore during the movement, so that the large particles can be lifted to the top position of each layer and concentrated to the place with strong crushing force. crushing ability.

02 Magnetic separator

Magnetic separation is one of the effective methods to remove iron-containing impurities in quartz ore, so as to remove weak magnetic impurity minerals such as hematite, limonite, and biotite including conjoined particles as much as possible.

Intensive magnetic separation usually adopts wet strong magnetic separator or high gradient magnetic separator. Generally speaking, for quartz whose impurities are mainly weak magnetic impurity minerals such as limonite, hematite, biotite, etc., it can be selected by a wet high-magnetic machine above 10000GS; for impurities mainly containing magnetite, for strong magnetic minerals, It is best to use a weak magnetic machine or a medium magnetic machine for sorting. In order to further remove a small amount of other weak magnetic minerals (such as amphibole, pyroxene, the combination of magnetic minerals and quartz), a high-gradient magnetic separator with a magnetic field strength greater than 12,000 Gauss can be used for secondary magnetic separation.

03 Flotation machine

Flotation is also a beneficiation method widely used in quartz ore processing plants, mainly to remove non-magnetic associated impurities such as feldspar and mica in quartz sand. The quartz sand beneficiation equipment used in this process is various suction mechanical stirring flotation machines (SF type flotation machine, BF type flotation machine, JJF type flotation machine) and air-filled mechanical stirring flotation machine (KYF type flotation machine). machine, XCF flotation machine)).

04 Obstructed settler

The hindered settler is a disturbance settling equipment, which is mainly composed of a cylinder, a bracket, a feed port, an overflow tank, a retaining ring, a support seat, a pressure detector, an electric valve and an automatic control system. . Special equipment especially effective for non-metals such as ores. The material is affected by the rising water flow in the cylinder to achieve the purpose of particle size classification and specific gravity separation, with high production efficiency and low energy consumption. It can be equipped with an automatic control system, and the adjustment of operating parameters is simple, convenient and easy to control. The water tank at the bottom of the cylinder can be equipped with a special rubber nozzle device. When the water stops, the rising water hole automatically closes,

In the quartz ore dressing plant, the hindered settler can strictly classify the coarse and fine particles, completely replacing the fine screen for particle size control.

05 XCⅢ Hydrocyclone

The XCIII hydrocyclone has a specially designed fish tail device in the grit chamber and a specially designed siphon device on the top of the overflow tank, so it has excellent characteristics that other hydrocyclones cannot match. Through the adjustment of the siphon device, a higher underflow concentration and a lower overflow concentration can be obtained. For the silica (quartz) industry, the overflow can be adjusted to almost release water and the underflow concentration can be as high as 85%. In addition, the specially designed fish tail device can keep the discharge concentration and overflow fineness of the swirl cone bottom flow constant when the ore feeding amount, ore feeding concentration and ore feeding pressure fluctuate within a certain range.

06 Summary

In the actual beneficiation process, the selection of quartz ore beneficiation technology and equipment is often determined according to various factors such as the nature of the quartz ore, the conditions of the beneficiation plant, and the investment budget. We need to comprehensively consider factors such as the actual situation and investment of the concentrator to determine the beneficiation plan, and customize the quartz ore beneficiation equipment to achieve an ideal return on investment.

Selection of spodumene flotation reagents

At present, the beneficiation methods of spodumene mainly include: manual separation, thermal disintegration, magnetic separation, resuspension method, flotation method and combined beneficiation method. Among them, the flotation method of spodumene is the most studied in the laboratory and the most widely used mineral processing method in industry.

1. Cationic collectors

The cationic collectors used in the flotation of spodumene ore are mainly amine collectors, which flotate gangue minerals such as quartz, feldspar and mica under acidic conditions, and leave the spodumene at the bottom of the tank. This method is often used in the roughing of spodumene, and cannot directly obtain spodumene concentrate with higher purity, and needs to be used in conjunction with other sorting methods.

In production practice, Yan Gengsheng used the process of flotation of spodumene with mixed soap and diesel oil under alkaline conditions after flotation of mica with phylloylamine under acidic conditions for a certain pegmatite spodumene ore. Mica concentrate and spodumene concentrate were obtained, and good economic benefits were obtained. In terms of single minerals, Yin Wanzhong and Sun Chuanyao studied the flotation of spodumene with the cationic collector dodecylamine without adding any activator and inhibitor, and obtained the result that the spodumene in the dodecylamine system The stone has better buoyancy conclusions.

2. Anionic collectors

The traditional spodumene anion collectors are mainly fatty acids and their soaps, namely oleic acid, oxidized paraffin soap, naphthenic acid soap, tar oil and sodium oleate, etc., alkyl sulfates and sulfonates, etc. However, due to the difference in ore properties, the increasingly complex ore composition and the comprehensive utilization of low-grade spodumene ore, the use of collectors has developed from a single drug to a mixed drug.

    Ren Wenbin used oximic acid to replace the original oxidized paraffin soap as a collector for the recyclability of spodumene tailings in Cocoto Sea, and the grade of spodumene concentrate was increased from 2.3% to 5.8%.

In terms of mixed drug use, in response to the problem of low recovery rate of high-grade spodumene of a granite pegmatite type in Jiangxi, Zhao Yun used oxidized paraffin soap and tall oil as a collector to obtain better indicators and solved the problem. The problem of low recovery rate.

Sun Wei and Ye Qiang used oxidized paraffin soap and naphthenic acid soap as collectors to conduct a flotation test on pegmatite-type spodumene (Li2O grade 1.42%) in a certain place in Sichuan, and finally obtained a concentrate with a Li2O grade of 6.04. %, a good indicator of the recovery rate of 85.88%. Liu Ningjiang conducted a flotation experiment on V26 and V38 spodumene of rare ore bodies in Keketuohai, Xinjiang, using strong stirring and scrubbing to remove sludge, and using cationic collectors and foaming agents to flotate mica under neutral and weak alkaline conditions. , and then mixed with sodium carbonate and sodium hydroxide to adjust the size, so that the pH value is 10.5 to 11.5, and the flotation process of using oxidized paraffin soap and naphthenic acid soap as collectors, obtained 5.65% to 6.37% of the flotation process. Spodumene concentrate, a good indicator of recovery of 80.77%.

3. New collectors

    In the research of spodumene collector selectivity, Wang Yuhua used a new type of chelating collector to replace the traditional oxidized paraffin soap, and realized the flotation separation of spodumene from quartz and feldspar, which not only can significantly reduce the cost of chemicals, And can greatly improve the separation between spodumene and quartz and feldspar, thereby improving the spodumene beneficiation index. At the same time, for the spodumene (Li2O grade 0.46%) and beryl in a granite pegmatite mineral, using the chelating collector YZB-17 can improve the grade and recovery rate of the mixed concentrate of spodumene and beryl. , and can realize the separation of spodumene and beryl.

    In the research on the collection performance of spodumene collector, Wang Yuhua studied sodium oleate, C7-9 hydroxamic acid, sodium dodecyl sulfonate and a new amphoteric collector YOA- The collection performance of 15 pairs of spodumene, the research results show that: the new amphoteric collector YOA-15 has a higher ability to collect spodumene than that of sodium oleate, C7-9 carboxyxamic acid and sodium dodecylsulfonate. Strong collecting ability. For the No. 3 vein spodumene ore and tailings in the tailings pond, the Cocoto Sea Concentration Plant used the new amphoteric collector YOA-15 to carry out flotation tests under different water quality, all of which showed strong collection capacity. With the foaming ability, a rough concentration of Li2O grade of 5.62% and a recovery rate of 83.3% can be achieved in one roughing.

    According to the research of many scholars, it is not difficult to find that there is less research on the reverse flotation process of spodumene, which may be related to the low content and grade of spodumene in the raw ore; in the positive flotation of anionic collectors, the traditional single It is difficult to meet the flotation separation of spodumene by the spodumene, and the combination drug is a new development direction; in terms of new collectors, it mainly focuses on multi-group chelating collectors and amphoteric collectors, but it is necessary to realize industrial production, there is still a long way to go.

Gold ore flotation process

The theoretical basis of various gold flotation processes is roughly the same, that is, gold ore particles can aggregate at the liquid-gas or water-oil interface due to the hydrophobic properties of their own surfaces or the hydrophobic properties obtained by flotation reagents.

The most widely used method is froth flotation. The ore is crushed and pulverized to dissociate various minerals into individual particles, and make the particle size meet the requirements of the flotation process. Various flotation agents are added to the milled pulp and mixed and mixed to interact with the mineral particles to expand the floatability difference between different mineral particles. The adjusted gold ore pulp is sent to the flotation cell, stirred and aerated.

The ore particles in the slurry contact and collide with the air bubbles, and the ore particles with good floatability selectively adhere to the air bubbles and are carried up to form a mineralized foam layer composed of gas-liquid-solid three-phase. The pulp surface overflows, and then dewaters and dries into a gold concentrate product. Mineral particles such as gangue that cannot float are discharged from the bottom of the flotation tank with the pulp as tailings.

The process is used to reflect the principle scheme of various ore sorting, including the process used for sorting, the sequence between each process, etc. Due to the large differences in the characteristics of gold mines such as khenbu particle size, dissemination characteristics, argillization characteristics, and associated mineral components, there are certain differences in the flotation process of different gold mines. The common principle processes are as follows:

1. Flotation + cyanide leaching

It is often used to treat sulfide ore containing a certain amount of gold and silver. In the process flow, the gold ore is firstly subjected to flotation operation, and a small amount of concentrate obtained by flotation is then subjected to cyanidation leaching. Compared with all-slime cyanidation, this process does not require fine grinding and leaching of all minerals, which is more time-saving, labor-saving and money-saving.

2. Flotation + concentrate roasting + calcine leaching

This gold ore flotation process is generally used for insoluble gold-arsenic ore, gold-antimony ore and gold-pyrite with extremely high sulfide content. A small amount of concentrate is obtained by flotation, which reduces the processing capacity of subsequent operations. The purpose of intermediate roasting is to remove elements such as arsenic and antimony that are harmful to cyanidation leaching.

3. Flotation + flotation concentrate pyroprocessing

A small amount of concentrate products should be obtained by flotation first, and then the remaining impurities should be removed by heating, melting and smelting. This gold ore flotation process is often used to treat most sulfide ores containing gold and silver. During the flotation process, gold and silver enter the closely related minerals such as copper and lead, and finally the flotation concentrate is sent to the smelter for purification.

4. Flotation + flotation tailings or medium ore cyanation + flotation concentrate roasting cyanidation in situ

This method is commonly used in the industry to process quartz sulfide ore containing gold telluride, pyrrhotite, chalcopyrite and other sulfide ores. The sulfide ore concentrate is obtained by flotation, and the gold and silver in it are exposed by roasting. Cyanide leaching was performed on the roasted product. At the same time, due to the high content of gold and silver in the middle and tailings obtained by flotation, it needs to be recovered by cyanidation leaching.

5. Raw ore cyanide + cyanide tailings flotation

For some sulfide ore containing gold and silver, cyanidation cannot completely recover the gold and silver in it, so the cyanided slag is flotated to improve the gold and silver recovery rate.

Gold ore flotation process is a relatively complex beneficiation process. In the beneficiation process, there are many types of flotation processes, such as preferential flotation, mixed flotation, partial mixed preferential flotation, equal flotation, branched series flotation, flash flotation, and rapid flotation.

Russia-Ukraine conflict brings uncertainty to global nickel supply

 Market research firm Fitch Solutions Country Risk and Industry Research (Fitch Solutions) said in its July 8 "Global Nickel Outlook" report: The Russia-Ukraine conflict has created uncertainty about the global supply of mined nickel - especially High-grade nickel used as battery-grade nickel in the electric vehicle (EV) industry.

Last year, Russian miner Norilsk Nickel alone provided about 17% of the world's primary nickel supply. Overall, Russia accounts for about 21% of global primary nickel production, followed by Canada with 17%, Australia with 14% and China with 10%.

While nickel is the fifth most common element on Earth and is currently mined in more than 25 countries, high-grade sulfide deposits located in mature mining areas are mostly depleted and require new and riskier jurisdictions Do additional exploration.

However, apart from the uncertainty surrounding Russia, high refined nickel prices and less disruption from the Covid-19 outbreak could lead to strong growth in nickel mine production this year and next, Fitch Solutions said.

The most important driver of this growth will be a recovery in production in Indonesia and the Philippines, where the Covid-19 outbreak has severely mining activity in 2020 and 2021.

Output in Indonesia was hit particularly hard last year, Fitch Solutions said, as a record number of Covid-19 cases led to the country's reimposition of lockdown restrictions. Fitch Solutions forecasts that global nickel production will grow at an average annual rate of 3.1% through 2026, before accelerating to an average of 5% by 2031.

Still, Fitch Solutions said both growth rates would be below the 6.6% year-on-year average achieved between 2010 and 2019, driven by higher nickel prices at the time and strong growth in Indonesian production. Fitch Solutions also said it expects annual global nickel production to reach 3.65 million tonnes by 2031, up from 2.46 million tonnes in 2021.

"As battery-grade primary nickel undergoes significant demand growth brought about by the green transition, the main supply risk and obstacle for battery makers is adequate primary supply," Fitch Solutions said.

Meanwhile, the company says the main potential "game changer" is the successful conversion of secondary nickel (low-quality nickel with a nickel content below 99.8%) to primary nickel.

However, the process, while promising, remains technically and environmentally challenging, which Fitch Solutions said points to tighter supplies of battery-grade nickel over the next two to three years - at a time when EV sales are expected to flourish. On the other hand, the supply of non-battery-grade nickel will remain ample.

Fitch Solutions said Australia and Indonesia would remain the world's largest suppliers of nickel. However, Australia will overtake Indonesia with its endowment of high-grade primary sulphide ore, while Indonesia plans to catch up by trying to convert its secondary nickel ore to primary.

The company also highlighted significant high-grade nickel opportunities in Canada, with substantial high-quality sulphide ore resources. Canadian Nickel also enjoys a better sustainability record and lower emissions than its competitors.

Overall, Fitch Solutions said high nickel prices and blocked nickel ore flows from Russia will drive investment in nickel ore from other markets, including Indonesia, the Philippines and Australia. This will lead to strong growth in nickel ore production this year and next, especially in Indonesia and the Philippines.

However, the company said the most vulnerable part of the global nickel ore supply pipeline - outside Russia - is in Indonesia, and any delay in the development of downstream nickel processing facilities could lead to the grounding of the country's nickel ore, reducing incentives for miners to boost output .

In addition, Indonesia will need to overcome technical challenges to cost-effectively convert an ample supply of secondary nickel ore into battery-grade primary nickel.

The complete method of copper oxide flotation

 Copper oxide is a black oxide of copper. In nature, copper is a typical sulphurophile element, mainly in the form of copper sulfide, but copper oxide minerals will be formed under strong oxidizing conditions.

Copper oxide is insoluble in water and/alcohol, soluble in acid, ammonium chloride and potassium cyanide solution, slow to dissolve in ammonia solution, can react with strong alkali, copper oxide is widely used in dry manufacture of ceramics, enamel, glaze, desulfurizer etc., can also be used to make oxygen, catalysts and green glass.

In the beneficiation process, most copper oxides need to be sulfided by chemicals, and then beneficiate. Compared with dry copper sulfide, the selection is more complicated and more chemicals are used. The beneficiation process of copper oxide (including oxygen-sulfur mixed copper ore) can be divided into two categories: flotation method and chemical beneficiation method. Below we mainly describe these two types of beneficiation processes.

• Copper oxide flotation method

Flotation is one of the commonly used beneficiation processes for copper oxide ore. According to the different properties of copper oxide ore, there are sulfide flotation, fatty acid flotation, amine flotation, and emulsion.

Flotation method and sting mixture-neutral oil flotation method, etc.

1. Vulcanization flotation method

Sulfation flotation method is divided into conventional sulfidation flotation and hydrothermal sulfidation flotation.

Conventional sulfidation flotation: This method is to first sulfide copper oxide minerals (using sodium sulfide or other vulcanizing agents), and then use good xanthate collectors to conduct flotation operations. The lower the value, the faster the vulcanization operation, and the more easily vulcanized with vulcanizing agents such as sodium sulfide.

The copper oxide minerals treated by the sulfide flotation method are mainly copper carbonates, such as malachite, azurite and other minerals, or cuprite, but the dry silica malachite needs special treatment first, otherwise the sulfurization effect Not good, not even vulcanized.

Note: When oxidizing copper minerals, it is recommended to add vulcanizing agents step by step, so that ammonium sulfate and aluminum sulfate can help the vulcanization of oxidized minerals.

Hydrothermal sulfidation flotation: This method extends the conventional sulfidation flotation method, which is to carry out the sulfidation operation under hot pressing conditions, so that sulfur chemically reacts with copper oxide under hot pressing conditions.

In order to obtain stable and easy-to-select man-made copper sulfide minerals, the same minerals are recovered by flotation of copper sulfide in warm water.

This method strengthens the pre-treatment of ore - the process of pre-vulcanization, but this process has high requirements on temperature, large fuel consumption and long vulcanization time.

2. Fatty acid flotation method

Fatty acid flotation, also known as direct flotation, mainly uses fatty acids and their soaps as collectors. During flotation, gangue inhibitor water glass, phosphate and slurry conditioner sodium carbonate are usually added.

Fatty acid and soap collectors can flotate malachite and azurite well, and use fatty acids with different hydrocarbon chains to flotate malachite. As long as the hydrocarbon chain is long enough, its collecting ability is very strong.

The fatty acid flotation method mostly uses dry gangue which is not a carbonate copper oxide mineral. If the gangue contains a large amount of iron, manganese and other minerals, its indicators will deteriorate, and the mesh sludge will also cause the fatty acid to fail.

3. Amine flotation method

This method mainly uses amines as collectors for flotation, which can not only be used for the separation of copper oxide, but also a common beneficiation method for copper oxide, lead and zinc minerals. Chlorothalmine, etc.

Amine type collectors are selective in choosing copper oxide, because amines also have a collection effect on many gangues. Before sorting, pre-desliming is required, but for argillaceous copper oxide, pre-desliming will lead to copper Therefore, the premise of choosing amine flotation method is to find an effective inhibitor of gangue first.

At present, gangue inhibitors include seaweed powder, xylinate (or cellulose xylosulfonate) and polyacrylic acid.

4. Emulsion flotation method

The flotation method is mainly to vulcanize copper oxide minerals first, then add copper complexing agents to form a stable lipophilic mineral surface, and then use neutral oil emulsion to cover the mineral surface.

surface, resulting in a highly hydrophobic floatable state, so that minerals can be firmly attached to the bubbles to complete the selection.

Emulsion flotation includes three aspects:

First, it is necessary to use selective organic copper complexing agent compounds, such as benzotriazole toluoyl triazole, mercaptobenzothiazole, diphenylguanidine, etc.;

One is to re-add non-polar oil emulsion to improve the adhesion between minerals and air bubbles. Non-polar oil emulsifiers include gasoline, kerosene and some oils, etc.

Third, selective inhibitors such as acrylic polymers and sodium silicate are required.

5. Chelating agent-neutral oil flotation method

This method refers to the use of a certain chelating agent and a neutral oil to form a collector to complete the flotation. It is mostly used for difficult-to-select copper oxides (such as silica malachite), which not only has high selectivity and collection effect, but also can It can ensure a high sorting index while reducing the consumption of chemicals, and the chelating agent also has a selective inhibitory effect.

However, the cost of the chelating agent is relatively high. At present, the chelating agents used include the basic dye malachite green substituted by octyl, potassium octyl hydroxamate, benzotriazole and neutral oil emulsifier, N-substituted iminodiethyl , acid salts, polyamines and condensates of organic halides, etc.

• Chemical beneficiation method

Chemical beneficiation methods are commonly used in dry refractory separation of copper oxide and mixed copper minerals with oxidation and sulfide. The use of chemical beneficiation method-combined process of copper oxide ore process can obtain good indicators, and it has many advantages such as simple process flow, low investment, low energy consumption, light pollution and low production cost.

The above are some common beneficiation methods for copper oxide minerals. For the selection of copper oxide minerals, it is necessary to determine the mineral composition and degree of difficulty of copper oxide minerals. It is recommended to find professional miners to conduct beneficiation tests, and customize the report according to the actual situation. In order to effectively select useful minerals from other places, remember not to apply them indiscriminately.