easily-extracted-gold-ore-and-its-processing-methods

5 Easily Extracted Gold Ores and 8 Processing Methods

Easily extracted gold ore has long been a major source of gold production in countries around the world, and such resources will be declining due to long-term mining.
In the paper, I list 5 Easily Extracted Gold Ores and 8 Processing Methods, let’s read on to find out!

What is Easily Extracted Gold?

1 Placer gold ore

Placer gold deposits are formed by primary gold deposits broken up by mechanical and chemical weathering and transported, sorted and deposited by external forces. There are many kinds of placer gold deposit, such as eluvial gold deposit, slope gold deposit, diluvial gold deposit, riverbed alluvial gold deposit and shore gold deposit, etc.

The characteristics of this kind of deposit are soft, shallow burial depth, generally 5~10m, some 20~30m; the thickness of gold-bearing deposit is generally 1~5m, individual up to 10m; The belt width is 50~300m on average, and the length can reach several kilometers or tens of kilometers; the slope of the gold deposit is very small, generally 0.002~0.02.

The gold ore is generally simple in composition, shape mostly in granular or scaly, and the particle size is usually 0.5~2mm, average density about 17.5~18.0g/cm3. According to the particle size, gold can be divided into a large piece of gold (greater than 5mm), coarse gold (5~1.65mm), medium gold (1.65~0.83mm), fine gold (0.83~0.42mm), extra fine gold (0.42~). 0.15mm) and the most particulate gold (or floating gold, less than 0.15mm).

2 Gold-bearing quartz vein ore

The basic composition of ore is quartz, with a content of more than 90%, and almost no heavy metal sulfide. Natural gold is mostly filled in the crack and cleavage surface of quartz in coarse grains, or disseminated in quartz veins in fine grains. Gold is easy to dissociate after crushing and grinding.

3. Gold-bearing quartz vein ore containing a small amount of sulfide

This ore is most common in gold-bearing quartz veins ore and generally contains 1% to 5% of metal sulfides. According to the state of gold production, it can be divided into two types: one is associated with sulphide ore, another is associated with gangue minerals such as quartz.

(1)Associate with sulphide ore
The composition of such ore is relatively simple. Pyrite is the main metal sulfide, and the content of sulfides such as copper, lead, zinc and antimony is very small. The relative content of natural gold in pyrite is more than 60%, and the remaining gold is present in gangue minerals such as quartz and other metal sulfides. This type of ore is most suitable for flotation. For the very fine gold contained in the flotation tailings, tailings cyanidation can be carried out. When the grinding product contains coarse particles of free gold, it should be added with mercury or gravity separation before flotation.

(2) Associate with gangue minerals
The main feature of this ore is that the metal sulfide content is low, and more than 70% of natural gold is symbiotic with quartz. The metal minerals in the ore are mainly pyrite. In addition, there is a small amount of chalcopyrite, pyrrhotite, stibnite, galena, etc., but no arsenic, antimony, clay and carbonaceous materials.
Such ores are more suitable for treatment by the “mercury + cyanide” method or the whole mud cyanidation method.

4 Quartz vein containing gold oxide ore

Oxidized ores are generally present in the shallower surface oxidation zone. According to the degree of oxidation, it can be divided into partially oxidized ore and oxidized ore. Most of the natural gold is found in gangue minerals and metal oxide minerals. The gold content of the ore is high, mostly between 10 and 20 gt. The surface of the gold particles often has an iron oxide film, and the degree of pollution increases with the increase of the oxidation rate of the ore. The commonly used processing method is “mercury (or gravity separation) and cyanide”, partially oxidized ore can use flotation process.

When the gold practices in the ore are coarse, the surface of the gold particles is clean, and the ore is not muddy, 70%~80% of the gold can be recovered from the ore by using the “single amalgamation” or “mixed mercury gravity separation” process.
When the ore with high oxidation degree, high content of mud, and series surface pollution, even though the particle size is coarse, it is not suitable to be directly treated by amalgamation. It must be gravity separated first, and the heavy sand (concentrate) is selected to be scrubbed by grinding machine to remove the surface contamination, then mix the mercury.
The fine particle ore with a low oxidation degree is usually treated by flotation.
As for the fine particle ore with high oxidation degree, and dispersed in non-sulfide minerals, even if the surface of the gold particles is not contaminated, the gold particles are too fine to be treated by the amalgam method. The only feasible treatment method is the whole mud cyanidation process, the gold leaching rate can reach 96%~98%.

5 Pyrite gold-bearing quartz vein ore

The mineral composition of this type of ore is similar to that of a small amount of sulfide quartz vein ore. The difference is that the sulfide content is high (5% to 15%). Metal minerals include pyrite, pyrrhotite, galena, sphalerite, chalcopyrite, and porphyrite, but pyrite accounts for more than 80%. The gangue minerals are mainly quartz, followed by calcite, feldspar, chlorite, sericite and the like.

Natural gold has a very close relationship with pyrite, so this type of ore is very suitable for flotation treatment, and the recovery rate can reach 93%~96%. If the ore contains coarse particles of free gold, it should be gravity separation before the flotation. When there are refractory gold-containing sulfide mineral particles in the flotation tailings, they can be recovered by the gold shaker.

8 Methods to Extract Gold

The gold beneficiation process of easy to separate gold ore consists of amalgamation, gravity separation, flotation, and cyanide. The choice of the extraction processing method depends on the nature of the ore and the requirements of the product form.
The commonly used beneficiation flow as following.

You may interest in gold processing solutions, get to know in different gold mine conditions and requirements, what gold processing machines used, and how the gold washing plant configuration.

1 Amalgamation

This procedure is suitable for the quartz primary ore and oxidized ore containing coarse gold. Simple layout, low investment, and fast effect, which is suitable for small gold processing plant.
related post: Gold Extraction Processing and Environment Consideration

2 Amalgamation – gravity separation

Two schemes: first amalgamation and then gravity separation or first gravity separation and then amalgamation. The former one is suited for the treatment of simple gold-bearing quartz vein sulphide ore, amalgamation process can recover the coarse particle-free gold, then gravity separation to select the heavy metal sulfide concentrate containing gold. The latter scheme, first gravity separation and then amalgamation, is suited for those oxidized coarse particle ore, and placer gold ore which with a low grade.

3 Gravity separation ( or amalgamation) – cyanide process

This flow design for gold-bearing quartz vein oxidized ores.
How to choose gold processing gravity separator? gold shaker table, centrifugal concentrator, spiral chute. Engineer online to help.

4 Flotation separation

the flotation process is commonly used to process the gold-bearing quartz vein ore which contains fine particle gold and good flotability sulfide ore, and process gold sulfide ore which contains several valuable metals (such as copper, lead, zinc). The flotation process can enrich gold and other valuable metals to the maximum extent, and waste tailings can be obtained with low production cost.

5 Mercury – flotation combined process

The basic premise of using this process is that the coarse gold in the ore can be recovered by amalgamation. the great feature of this process is that can achieve a higher recovery rate than a single flotation process. In addition to the ore processed by the above flotation process, gold-bearing oxidized ore and ore associated with free gold are suitable.

6 Cyanidation (full mud cyanidation) process

As for such gold ore, in the presence of a fine particle in quartz gangue minerals, which are deeply oxidized and do not contain Cu, As, Sb, Bi and carbonaceous materials, is suited for adopts cyanidation.
Advantages: low cyanide consumption, high leaching rate, high efficiency and easy control.

7 Flotation – cyanide process

This combination is mainly used to process gold-bearing quartz vein ore and quartz-pyrite ore those have close symbiosis relation of sulfide. Compared with the cyanidation process, the flotation – cyanide process has the advantages as following:
does not require a fine ground particle, saving consumption; lesser washing and mixing step; smaller area required, low investment.

8 Flotation – gravity separation

It is mainly based on flotation, and is suitable for the ore that is closely symbiotic with GOL and sulfide, and can only be recovered by smelting. Due to the small amount of non-floating sulphide ore particles (mostly pyrrhotite) in the flotation tailings, it needs to be recovered by using a gold shaker table, spiral chute and cyclone.

In summary, the choice of gold processing flow is closely related to the nature of the ore. For some complex gold-bearing ores, especially refractory polymetallic gold-bearing ores, it is technically necessary to select or develop a combination of the gold processing methods in order to maximize gold recovery and efficiently recover various useful ingredients.

Indium

World’ 10 Most Precious Metals

The precious metal always reminds us of gold, silver and the stuff related to money, but if you think gold or silver is the most expensive metal in the world, you’re wrong.

The so-called precious metal, that is, the metal with low content in the earth’s crust, which is difficult to explore, mine, and refine. Most of the precious metals have beautiful colors, and they are quite resistant to chemicals. Due to its unique physical and chemical properties, it is irreplaceable by other metal materials and plays a key role in some applications.

What is the most expensive metal? Join us to explore the world’s top 10 precious metals.

Among all precious metals, gold is one of the rarest, rarest and most valued metals, silver is the same. We can often see them in ornaments, instruments and electronic products.

But does not know that some platinum group metals (platinum, rhodium, ruthenium, palladium, iridium, osmium), they are not well known to us, also within precious metal group.

1. Rhodium

Rhodium is a silver-white, hard metal with high reflectivity, it usually doesn’t form oxides. Even atmospheric oxygen is absorbed by heated rhodium, but it is released during solidification. Rhodium is insoluble in most acids, completely insoluble in nitric acid, slightly soluble in aqua regia.
The content of rhodium elements in the earth’s crust is only one part per billion, scatter in various ores, definitely is the most expensive metal.

Latest price: 2,175.00 USD per Troy Ounce
Main producers: South Africa, Russia, Canada and other countries.
Application: Rhodium is corrosion resistant and has good luster. It is mainly used in the electroplating industry. Electroplate it on other metal surfaces, the coating color is firm, not easy to wear, and has good reflectivity.

2. Platinum

Platinum is thirty times more rare than gold and can only be mined in very few parts of the world. If all the platinum in the world is poured into an Olympic standard swimming pool, its depth is not enough to cover the instep, and gold can fill at least three swimming pools.
Application: Platinum is very stable in nature and will not deteriorate or fade due to wear, it is a good choice for jewelry, It has been regarded as the most expensive metal in the 2000-year history of human use of platinum, and is sought after by the royal family. Besides, platinum is not soluble in any acid or alkali except aqua regia, can be used to make corrosion-resistant chemical equipment. In medicine, it can be used as an anticancer drug.
Main producer: South Africa, Russia, Canada
Latest price: 845.00 USD per Troy Ounce

Platinum

3. Gold

Because of its luster and durability, gold is the easiest identified precious metal and remains the popular and investment options.
Gold is usually extracted from rocks and placer sand by gold mining equipment and a series of mineral processing activities like crushingwashingflotation, and gold refining process.

Application: Gold has excellent ductility and corrosion resistance, it can be used not only as an ornament, but also in instrument manufacturing and electronic industry.
Main gold producer: South Africa, America, Australia and China
Latest price: 1,451.85 USD per Troy Ounce

gold

4. Ruthenium

Ruthenium, a member of the platinum group, is one of the rarest metals, found in the earth’s crust at only one part per billion. Ruthenium is stable to nature, resistant to corrosion, and popular for its ability to increase hardness and resistance.

Application: Ruthenium is widely used in jewelry, electronics, chemical and other industries.
Main producer: Russia, North and South America
Latest price: 255.00 UDS per Troy Ounce
Photo: Wikipedia

Ruthenium

5. Iridium

Iridium is one of the densest metals in the world, has a very high melting point and excellent corrosion resistance. Iridium is processed from platinum ore and is one of the by-products of nickel.

Application: Mainly used in the manufacture of scientific instruments, thermocouples, resistors, etc. High hardness iron – Iridium alloy and iridium – platinum alloys are commonly used to make nib and platinum jewelry. Due to its extremely high melting point and superior corrosion resistance, iridium is widely used in high-level technology fields such as aerospace technology, pharmaceuticals and the automotive industry.
Main producer: South Africa
Latest price: 520.00 USD per Troy Ounce
Photo: Wikipedia

Iridium

6. Osmium

Osmium is the densest metal is known, which can be used to make super hard alloys.
Add a little osmium in platinum, can make a hard and sharp osmium platinum alloy scalpel. Osmium – iridium alloy is hard and wear-resistant, can be used to make bearings for clocks and important instruments and greatly prolong the service life.

Main producer: North and South America, Russia
Latest price: 400.00 USD per Troy Ounce
Photo: Wikipedia

Osmium

7. Palladium

Palladium is one of the richest and widely used platinum metals. It is the trading variety of international precious metals spot and futures with platinum, gold and silver.
Palladium is a rare non-renewable resource, is an indispensable key material in the high-tech fields of aerospace, aviation, navigation, weapons and nuclear energy as well as the automobile manufacturing industry.

Applications: Petrochemical industry, automobile manufacturing, chemical industry, electroplating, jewelry, etc.
Main producer: Russia, United States, Canada
Latest price: 1400.00 USD per Troy Ounce
Photo: Wikipedia

Palladium

8. Rhenium

Rhenium is one of the rarest elements in the earth’s crust, and one of the elements with the highest melting and boiling point. Rhenium is the only refractory material that does not form carbide. Since 1925, it has been actively used in the chemical and electronic industries.

Application: Rhenium can be used in high-efficiency jet engines and rocket engines, which is the largest practical application of rhenium, followed by the catalyst in the chemical industry.
Main producer: Kazakhstan, Chile and America
Latest price: 1290.00 USD per Troy Ounce
Photo: Wikipedia

Rhenium

9. Silver

Silver, like gold, is a precious metal with a long history of the application. It is a beautiful metal with good ductility and has the highest electrical and thermal conductivity among all metals.

Applications: Silver is often used to make highly sensitive physical instrument components used in various automation devices, rockets, submarines, computers, nuclear devices and communication systems. Also use for jewelry, circuits, batteries, coins, etc.
Main producer:Peru, China, Mexico and Chile
Latest price:16.55 USD per Troy Ounce
Photo: Wikipedia

silver

10. Indium

Indium is a silver-white, bluish-tinged metal, so soft it can be scratched with a fingernail. Indium has high ductility and malleability, which is mainly used in the manufacture of ITO material (in the liquid crystal display and flat screen), alloy, semiconductor, electric light source and so on.

Main producer:China, South Korea and Japan
Latest price:250.00 USD per Troy Ounce
Photo: Wikipedia

Indium

The preciousness of precious metals is not only because of its scarce reserves in nature, but more importantly because of its unique physical and chemical properties, such as corrosion resistance, mechanical properties, catalytic properties, high-temperature resistance. precious metals are used in areas such as national defense, financial reserves, energy, electronics, aerospace, in addition, in the medical field, precious metals also have important uses, especially in the treatment of cancer. For example, oxaliplatin has significant inhibitory effects on various animal and human tumor cell lines such as colorectal cancer, non-small cell lung cancer, ovarian cancer, and breast cancer.

gold stone

Vein Gold Beneficiation Processing

Vein gold, is also known as lode gold, there are many types of vein gold ore, which can be summarized as gold-bearing quartz vein or gold-bearing pyrite quartz vein gold ore; gold-bearing pyrite granite type; gold-bearing polymetallic sulfide ore quartz vein type; gold-containing oxidized ore quartz vein type and gold-containing tungsten-arsenic ore quartz vein type.
According to the characteristics of each type of ore, vein gold beneficiation processing methods include gravity separation, amalgamation, flotation, cyanide, the carbon in pulp and resin adsorption.

1 Gravity separation

Gravity separation is one of the oldest and most common gold extraction methods. In the placer gold deposits, the density of gold is generally greater than 6t/m3, which is different from the density of gangue. Therefore, the gravity separation method is the most important, effective and economical method for gold mining.
However, it is rarely used alone in the vein gold processing plants, more often combines the jigging machine, shaker table or spiral chute to recover the coarse gold. That is beneficial to improve the flotation and cyanide effect.

Main gravity separators: spiral chute, mineral jig, shaker tables, centrifugal concentrator, etc.

2 Amalgamation

The amalgamation method can be divided into internally mixed mercury and externally mixed mercury according to its production mode. In the alluvial gold deposit mining, mercury is widely used to separate gold and heavy sand minerals. In the vein gold mine, amalgam is usually used as part of the combined process with flotation, gravity separation, cyanidation, etc., for the capture of coarse monomers gold.

The internal amalgamation is carried out in a mercury amalgamation tank or a grinding machine, which can better control the pollution of mercury.

The main equipment for external amalgamation is a mercury-mixing plate, which consists of a bracket, a bed surface and a mercury plate. The mercury plate material various in copper plate, silver-plated copper plate, sterling silver plate, etc., and the silver-plated copper plate has the best mercury-mixing effect. In order to facilitate silver plating and easy replacement in production, the electrolytic copper plate is often cut into small pieces of 400-600 mm in width and 800-1200 mm in length, and after silver plating, the blocks are laid on the bed surface in the oblique direction of the bracket.

3 Gold flotation

Flotation is one of the most widely used methods for processing lode gold ore. In most cases, the gold flotation method has the best effect in the sulfide mineral ore containing gold. Flotation can not only maximize gold enrich into sulfide mineral concentrates, but also treat tailings.
The flotation process is also used to treat polymetallic gold-bearing ores such as gold-copper, gold-lead, gold-bismuth, gold-copper-lead-zinc-sulfur ore. For this type of ore, the flotation process can effectively select various gold-bearing sulfide concentrates, which is conducive to the comprehensive recovery of mineral resources.
In addition, the refractory ores that cannot be directly treated by amalgamation or cyanidation are also required to be treated by a combined process including flotation.
Of course, the flotation method also has limitations; for coarse-grained inlays, ores with a gold particle size greater than 0.2 mm, and for quartz-bearing gold-bearing ores without sulfides, it is difficult to obtain a stable flotation foam after slurrying, thus not suit for using flotation.

In recent years, the flotation process of gold ore has made great progress, mainly in the innovation of process, the development of new agents, and the improvement of design. The use of stage grinding and stage selection process is the current development trend of flotation gold selection. Most foreign gold selection plants use two or even three sections, and the recovery rate of gold is increased by 2% to 6%.

Because the flotation method can only maximize the concentration of gold into various sulfide mineral concentrates, and can not finally obtain the finished gold, therefore, there are only a few gold selection plants using a single flotation process, generally the flotation is used as a joint. A process of the process is adopted. At present, China’s gold selection plants using a single flotation process include gold mines such as Suichang and Xiuyan, as well as small gold mines in some local groups.

4 Cyanidation

Since the cyanidation process was applied to the gold and silver mines in 1887, it has a history of nearly one hundred years. Because of its high recovery rate and strong adaptability, it is still one of the main methods of gold production.

The cyanidation process can be divided into agitating cyanidation and diafiltration cyanidation. Stirring cyanidation for treatment of re-election, mercury-mixed tailings and flotation of gold-bearing concentrates, or for full mud cyanidation; and diafiltration cyanidation for treatment of flotation tailings and low grade gold Heap leaching of ore. The conventional cyanidation process is a very mature process, which includes preparation of leaching raw materials; stirring cyanide leaching; countercurrent washing solid-liquid separation; leaching liquid purification and deoxidation; zinc powder replacement and pickling; and smelting ingots and the like.

5 Cyanide carbon in pulp (CIP)

The CIP process is a new technique for recovering gold and silver after developing based on conventional cyanide leaching and zinc powder replacement. It is mainly composed of leaching raw material preparation, stirring leaching and countercurrent carbon adsorption, gold loaded carbon desorption, electrowinning or deoxidizing zinc powder replacement, smelting ingots and regeneration of activated carbon.

6 Heap leaching

Heap leaching is the transfer of the mined ore to a pre-prepared yard to pile up, or directly on the stored waste rock or low-grade ore, using cyanide leaching solution for spraying or diafiltration, so that the solution passes through the ore. The percolation leaching action is generated, the cyanide leaching solution is circulated several times, the ore heap is repeatedly sprayed, and then the leachate is collected, and then treated by activated carbon adsorption method or metal zinc replacement method. The gold grade of the ore treated by the heap leaching method in foreign countries is generally 1~3g/t, the recovery rate of gold is 50%-80%, and the recovery rate of silver is 30%-50%.

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Is Deep Sea Mining bad for the environment?

Scientists Worry: Deep Sea Mining Will Harm the Earth’s Ecology

“Although commercial exploitation of the bottom of the deep sea may become a reality in the next few years, researchers from Greenpeace Organization recently warned that deep-sea mining exploration could be a deadly blow to an already fragile marine ecosystem and cannot be reversed.”

As the world’s population grows larger, the rapid growth of human demand for resources is dragging human development into a new low. Although commercial exploitation of the bottom of the deep sea may become a reality in the next few years, researchers from Exeter University and Greenpeace Organization recently warned that deep-sea mining exploration could be a deadly blow to an already fragile marine ecosystem and cannot be reversed. The results of this research were published in Front. Mar. Sci.

Deep sea area refers to the area below 3000 meters in altitude, covering nearly 50% of the earth’s surface. That is a big cake enticing global mining companies.

Only a small part of the deep sea area has been explored until now, and these mysterious places are full of untapped treasures. In a world full of countless marine life, it is rich in manganese, sulfide, phosphate, and even diamonds. This is very tempting for the mining industry!

Several companies, such as Nautilus Minerals and Diamond Fields International, have successively stated that mining these resources will ensure a stable supply of human resources in the coming decades.

However, the new report, written by scientists and related policy experts, argues that deep-sea mining is not in the interest of mankind or the world as a whole, and could also pay a heavy price.

The deep ocean of the earth is closer to us than the moon, but humans do not acquaint with the deep sea even than Mars. It is difficult to say what the potential damage caused by deep-sea mining is, and the only little knowledge and experience currently tells us that the ocean doesn’t like to be disturbed.

In fact, some scientists believe that deep-sea mining could lead to widespread habitat loss and mass extinction. Today, most marine scientists around the world have reached a consensus that any large-scale seabed mining activity will consume resources, disrupt, destroy or eliminate the structural elements of ecosystems, cause loss of biodiversity and affect ecosystems.

The marine ecosystem is currently facing many threats, such as climate change, ocean acidification, pollution, offshore drilling, and pressure from shipping and fisheries, which has caused countless man-made disasters in the underwater world. Therefore, the report calls on human beings to remain vigilant, propose a coherent and effective marine policy, establish more marine protected areas (MPAs) and more transparent management agencies.

The report shows that the mining industry is now competing for subsea mining licenses in a variety of ways. Catherine Miller, a researcher at Greenpeace International, said, “Many marine scientists worry that once the first mining commercial contract is awarded, there is no way back.

The report states that a “circular economy” built on mineral reuse and recycling is sufficient in itself to reduce unsustainable material consumption. David Santillo, a marine biologist at the University of Exeter, says whether we should allow subsea mining that poses risks to deep-sea ecosystems, or should we focus on reducing demand for virgin minerals? Before making any hasty decision, we should carefully consider the answer.

mine feild

How Much it Costs to Start a Rock Quarry Plant

The preparatory work for operating a quarry is divided into the early stage and the later stage, the early stage is mainly to apply for sand mining qualification. This article mainly introduces the later stage work, that is, buying quarry equipment. Answer your questions like ‘What is quarry machine‘, ‘quarry equipment cost‘.

What is quarrying

Quarrying is mainly to provide qualified construction aggregates for high-grade highways, high-speed railways, roads, and bridges. In addition to natural stone, quarrying equipment can also be used to produce artificial sand, such as mine tailings sand, urban construction waste sand, and other machine-made sand industries.

What is the rock quarry equipment

The quarry equipment mainly includes feeding, crushing, screening, sand making, conveying and material transportation equipment. Among them, the crushers are the most critical and expensive equipment in the entire rock quarrying system.

Generally speaking, the quarry used rock crushers are divided into coarse crushing, medium-fine crushing and sand making machine. PE jaw crusher, single-cylinder cone crusher, and sand making machine correspond to coarse crushing, medium-fine crushing, and sand-making respectively. They are high-yield, cost-effective, and are your good choice.

Vibrating feeder

The feeder can transport stones and rocks to the crushing equipment in a timely, regular and continuous manner, with high efficiency and energy saving, small footprint, convenient adjustment and long service life.

Cone crusher

Cone crusher is mainly used for medium-fine crushing, such as iron ore, non-ferrous metal ore, granite, limestone, quartzite, sandstone, river pebble, etc. For hard stones such as cobblestone, granite, coal gangue, if adopt the crushing process of “jaw crusher + sand maker”, it may cause serious wear of the sand maker. In order to relieve the pressure of the sand making machine, a cone crusher is added in the middle.
From the process point of view, adding equipment is equivalent to increasing investment costs, but for long-term investment in quarry mining work, reducing the wear on fine sand making equipment, increasing the service life, creating more profits.
Single-cylinder hydraulic cone crusher combines mechanical, hydraulic, electrical, automation, intelligent control and other technologies into one. It has the advantages of high crushing efficiency, convenient maintenance and adjustment, and excellent particle shape of the crushed product, widely used in metal, non-metallic ore, cement, sand and stone, metallurgy and other industries.

Jaw crusher

PE jaw crusher is used in the first process of various rock crushing, can crush rock with compressive strength not higher than 320MP and a maximum feed particle size of 125mm ~ 1020mm to medium particle size. It has a good crushing effect on quarries based on raw materials such as limestone, cobblestone, granite, basalt, calcium carbide, and coal gangue. Large jaw crushers are favored by quarry investors due to their large processing capacity and strong market competitiveness.

Sand making machine

Sand making machine, or called vertical shaft impact crusher (VSI), crushes 30-50mm stone to 0-5mm by impact energy. The vertical shaft impact crusher adopts a new four-port impeller design structure and is equipped with a special seal structure to prevent oil leakage from the bearing cylinder. VSI crusher is efficient sand making equipment, can crush all kinds of ultra-hard, medium-hard and corrosive materials, provides high-quality aggregates for expressways, high-speed railways, high-rise buildings, municipal administration, hydropower dam construction, and concrete mixing stations

Quarry equipment price

Frankly, there is no an exact price of how much will a rock quarry plant requires, price is varied in material, capacity, final product quality. Before starting a quarrying business, it is necessary to make a comprehensive assessment of stone prices, market demand, equipment prices, policies, site conditions, and rock quarrying process technology.

Ghana-mining

Gold Mining in Ghana

Ghana has replaced South Africa as the largest gold producer on the African continent, which is no longer news for smart and important mining investors. Ghana ’s mining industry is almost all gold mining.

Ghana ’s gold production can be traced back to the colonial period, although the output was small at that time, until the 1970s and 1980s, Ghana began to open up mineral resources and carry out exploration work.

Today, several world ’s top gold giants have established gold mining bases in Ghana to participate in gold exploration and mining. These large gold mining companies include Gold Fields Limited, Toronto-based IAMGOLD Corp, AngloGold Ashanti Ltd., Golden Star Resources Ltd and Newmont Mining Corporation. Other important companies that are conducting gold exploration in Ghana include Adamus Resources Ltd., Xtra Gold Resources, African Gold plc, Perseus Mining Limited, Moydow Mines International Inc. and Pelangio Mines Inc.

Although Ghana ’s recent actions against illegal gold mining are in full swing, Ghana still leaves huge investment potential for legitimate gold investors. Some of the major gold mines currently operating in the country include:

  1. Taekwa Gold Mine
    This is the largest gold mine in Ghana. The mine is owned and operated by Goldfields. It has about 15.3 million ounces of gold resources and about 9.9 million ounces of gold reserves.
  2. Chirano Gold Mine
    This open-pit mine is located in western Ghana, about 20 kilometers south of the Bibiani gold mine. The mine was started by Red Back Mining Company in 2005 and operated by Chirano Gold Mines Limited (CGML), a subsidiary of the company. The mine currently produces an average of 3,800 kg of gold per year.
  3. Nzema Gold Mine
    The mine is located in the Ashanti gold belt in southern Ghana. It is owned and operated by Endeavor Mining Company, which started commercial mining in 2011.
  4. Iduapriem open pit mine
    The mine is owned by AngloGold Ashanti and is located about 10 kilometers south of the larger Tarkwa mine in western Ghana. The mine consists of two mining operations: Teberebie and iduapriem.
  5. Obuasi underground mine
    The mine is located in Obuasi, Ashanti region, which is one of the top ten gold mines in Africa. The mine is owned by AngloGold Ashanti. The mine has been in operation since 1897 and is considered to be one of the oldest gold mines in Ghana.
  6. Wassa open-pit gold mine
    The open-pit mine is located about 35 kilometers northeast of Tarkwa and about 150 kilometers north of Accra. The mine has been in operation since the early 1990s and is estimated to have approximately 2 million troy ounces of gold reserves.

As the top gold producer in Africa, Ghana has a considerable number of gold mines being mined or constructed. Other important mines include Bogoso Gold MinePrestea Underground Gold MineAhafo Gold Mine and Damang Gold Mine.

From December 17, 2018, the government of Ghana officially lifted the ban on small-scale gold mining, allowing small-scale gold mining enterprises in Ghana that have been audited by the Ghanaian government and have full certificates to resume mining.

However, the Ghanaian government also emphasized that lifting the ban on small-scale gold mining is not lifting illegal gold mining. Any gold mining that is not approved by the Ghanaian government is illegal. The lifting of small-scale gold mining is only for citizens of Ghana. It is still illegal for foreigners to participate in small-scale gold mining.

timthumb

Ways to Improve Sand Washing Efficiency

  • What to do if the sand washing machine has a poor cleaning effect? 
  • The efficiency of a sand washing machine is low, how to increase production capacity? 
  • How to deal with the frequent failure of sand washing machines that affects production? 

  • Prevent debris from entering the charging port

The cleanliness and mud content of sand are one of the reasons for the decline in the output of sand washing machines. 

During the cleaning process of the sand washer, it is necessary to prevent impurities from affecting the cleaning effect of the finished product. In addition, it is necessary to prevent materials with high hardness from entering the inside of the machine, which will cause wear to the equipment and reduce the service life.

  • Control the liquid level of the sand washing machine reasonably

If the liquid level is too low, the cleaning effect cannot be achieved; while the liquid level is too high, water resources are wasted, but the ideal cleaning effect is not achieved, and the ore is likely to overflow. The amount of materials for one-time cleaning must be within the specified range, otherwise it is prone to failure.

  • Adjust the concentration to the critical value

Ore concentration is the main factor that needs to be adjusted during the operation of the sand washing machine. It is related to the graded particle size and also related to the processing capacity under this particle size.

The processing capacity of the sand washing machine reaches the maximum under the critical concentration. The critical concentration is related to the specified graded particle size and changes with the density of the ore and the mud content. 

The higher the ore density or the lower the mud content, the higher the critical concentration, and vice versa Of course, the relationship between the critical concentration and the graded particle size is the same as the mud content, that is, the lower the graded particle size, the smaller the critical concentration.

  • Clarify sand and gravel properties

The production capacity of the sand washing machine is related to the properties of sand and gravel, including the hardness, density, mud content, particle size of the sand and gravel materials. For example, the uneven sand and gravel materials and their own different attributes may affect the processing capacity of the sand washing equipment. The density of the material is directly proportional to the production capacity of the sand washing machine. The influence of mud content and ore size is mainly reflected in the viscosity of the slurry, which reduces the viscosity and increases the sedimentation speed of mineral particles. The processing capacity and classification accuracy of the sand washing machine will be better.

  • Make sure the installation location is appropriate

The sand washer should be placed in a suitable location, it can be placed on a flat ground, or placed at a high place, but the plane must be hard enough, and it must not be placed close to the water source. These places are prone to collapse. Cause unnecessary production troubles. In addition, there must be sufficient production space to ensure stable material transportation and production, and sufficient storage space for machine-made sand after cleaning to avoid secondary pollution.

  • The operators should be properly trained

According to our research, more than 60% of low or affected production capacity  may be caused by the error or Illegal operation. Poor technical level will affect the normal operation of the equipment, and will greatly reduce the production efficiency of the sand washing machine. In some cases, those wrong operations may even break the equipment.

  • Daily inspection

Before the machine runs, checking the equipment carefully is highly recommended. This rule is not only suitable for sand wash machines, but also for all kinds of equipment.

Here are some aspects you should checked before run the sand washer:

  1. Check whether there are residual impurities in the bucket, discharge port, water storage tank, etc. of the equipment. If necessary, remove them immediately. Make sure that the passage of each component is unobstructed and clean.
  2. Check the firmness of the equipment connection anchor bolts, take firm measures for loose bolts, and ensure the stability of the connection of the equipment components, especially the tightness of the screws.
  3. The oil quantity of the reducer should be checked in time during operation, and the gear transmission of the equipment should be kept in good gear to ensure that the gear transmission belt is not worn or damaged.
  4. The feeding of equipment should be ensured continuously and evenly, and it should not be too much or too little, which will result in insufficient material cleaning.
  5. Each rotating bearing and reducer should ensure that the lubricant is sufficient and clean. At the same time, it is necessary to select a suitable lubricant to increase it. The lubricant of the reducer should be replaced on time after one month of use. The process must ensure the cleanliness of the equipment bearings and adding pipes to prevent contamination of the lubricant.
  6. The sand washing machine should be cleaned in time after use, otherwise the pipeline will be blocked after a long time.
  7. Regularly observe the internal wear and tear of the sand washer. If parts are found to be worn to affect production and operation, they must be repaired or replaced in time.

In the long-term production and operation process, the sand washing machine will affect the sand washing effect and efficiency due to various problems. If you also encounter this problem in future production, you may wish to check the above 7 aspects to find the right cause and prescribe the right medicine. 

We hope those methods will help you when you meet those situations.

  • What to do if the sand washing machine has a poor cleaning effect? 
  • The efficiency of a sand washing machine is low, how to increase production capacity? 
  • How to deal with the frequent failure of sand washing machines that affects production? 

 

  • Prevent debris from entering the charging port

The cleanliness and mud content of sand are one of the reasons for the decline in the output of sand washing machines. 

During the cleaning process of the sand washer, it is necessary to prevent impurities from affecting the cleaning effect of the finished product. In addition, it is necessary to prevent materials with high hardness from entering the inside of the machine, which will cause wear to the equipment and reduce the service life.

  • Control the liquid level of the sand washing machine reasonably

If the liquid level is too low, the cleaning effect cannot be achieved; while the liquid level is too high, water resources are wasted, but the ideal cleaning effect is not achieved, and the ore is likely to overflow. The amount of materials for one-time cleaning must be within the specified range, otherwise it is prone to failure.

  • Adjust the concentration to the critical value

Ore concentration is the main factor that needs to be adjusted during the operation of the sand washing machine. It is related to the graded particle size and also related to the processing capacity under this particle size.

The processing capacity of the sand washing machine reaches the maximum under the critical concentration. The critical concentration is related to the specified graded particle size and changes with the density of the ore and the mud content. 

The higher the ore density or the lower the mud content, the higher the critical concentration, and vice versa Of course, the relationship between the critical concentration and the graded particle size is the same as the mud content, that is, the lower the graded particle size, the smaller the critical concentration.

  • Clarify sand and gravel properties

The production capacity of the sand washing machine is related to the properties of sand and gravel, including the hardness, density, mud content, particle size of the sand and gravel materials. For example, the uneven sand and gravel materials and their own different attributes may affect the processing capacity of the sand washing equipment. The density of the material is directly proportional to the production capacity of the sand washing machine. The influence of mud content and ore size is mainly reflected in the viscosity of the slurry, which reduces the viscosity and increases the sedimentation speed of mineral particles. The processing capacity and classification accuracy of the sand washing machine will be better.

  • Make sure the installation location is appropriate

The sand washer should be placed in a suitable location, it can be placed on a flat ground, or placed at a high place, but the plane must be hard enough, and it must not be placed close to the water source. These places are prone to collapse. Cause unnecessary production troubles. In addition, there must be sufficient production space to ensure stable material transportation and production, and sufficient storage space for machine-made sand after cleaning to avoid secondary pollution.

  • The operators should be properly trained

According to our research, more than 60% of low or affected production capacity  may be caused by the error or Illegal operation. Poor technical level will affect the normal operation of the equipment, and will greatly reduce the production efficiency of the sand washing machine. In some cases, those wrong operations may even break the equipment.

  • Daily inspection

Before the machine runs, checking the equipment carefully is highly recommended. This rule is not only suitable for sand wash machines, but also for all kinds of equipment.

Here are some aspects you should checked before run the sand washer:

  1. Check whether there are residual impurities in the bucket, discharge port, water storage tank, etc. of the equipment. If necessary, remove them immediately. Make sure that the passage of each component is unobstructed and clean.
  2. Check the firmness of the equipment connection anchor bolts, take firm measures for loose bolts, and ensure the stability of the connection of the equipment components, especially the tightness of the screws.
  3. The oil quantity of the reducer should be checked in time during operation, and the gear transmission of the equipment should be kept in good gear to ensure that the gear transmission belt is not worn or damaged.
  4. The feeding of equipment should be ensured continuously and evenly, and it should not be too much or too little, which will result in insufficient material cleaning.
  5. Each rotating bearing and reducer should ensure that the lubricant is sufficient and clean. At the same time, it is necessary to select a suitable lubricant to increase it. The lubricant of the reducer should be replaced on time after one month of use. The process must ensure the cleanliness of the equipment bearings and adding pipes to prevent contamination of the lubricant.
  6. The sand washing machine should be cleaned in time after use, otherwise the pipeline will be blocked after a long time.
  7. Regularly observe the internal wear and tear of the sand washer. If parts are found to be worn to affect production and operation, they must be repaired or replaced in time.

In the long-term production and operation process, the sand washing machine will affect the sand washing effect and efficiency due to various problems. If you also encounter this problem in future production, you may wish to check the above 7 aspects to find the right cause and prescribe the right medicine. 

We hope those methods will help you when you meet those situations.

hydraulic

Types, Causes And Treatment Methods For Hydraulic System Failures

01. System running with loud noise

  1. The main noise in the hydraulic system is from the hydraulic pump. Its pressure fluctuation and structural vibration cause the noise of the machine and equipment, such as the phenomenon of suction, the oil suction filter will be blocked locally, and the suction pipe is away from the oil surface If it is relatively close, this will cause loud noise of the pump. When this problem occurs, you may need to add enough oil according to the regulations, clean the oil filter, and tighten the connecting screws.
  2. Valve springs, valve reversal, and poor pressure valves can also cause loud noises. The failure manifests itself in the form of pressure changes. Air entering the hydraulic cylinder will cause system noise and resonance. If cavitation occurs, check whether the oil level and sealing device are normal, and remove the air in the pump.
  3. As in some situations when one end of the hydraulic system is a valve and the other end is a large container, it is easy to produce pressure shocks. At this time, the instantaneous pressure peak is many times higher than the normal value, which will cause the vibration of the actuator, normal operation will be affected, and noise will be generated. Such actions often cause wrong actions in some components.

02. System temperature running too high

Another common fault of mining machinery hydraulic systems is that the temperature is running too high. Generally speaking, it is normal for the temperature of the machine to increase after a period of time. However, if the high temperature is not controlled, the machine will be damaged, even causing mechanical spontaneous combustion, with serious consequences.

When the system is overheated, check whether there is oil leakage inside, whether the pump is worn, if there is oil leakage, it should be replaced in time, also check whether the pressure setting value of the safety valve is faulty, and set the value in time. When the pump is installed too tightly, it can also overheat the system.

03. The system pressure is abnormal

Here are some common reasons that may cause abnormal pressure in the system.

  1. The oil level in the fuel tank is too low, the system pressure is under normal operation, and the component does not move or the component moves slowly when the actuator is working.
  2. The opening of the relief valve is damaged, and the setting value of the pressure reducing valve is low, resulting in insufficient system pressure. If the oil viscosity is too high or too low, the control pressure of the valve is not enough, and the orifice in the valve is blocked.
  3. The oil temperature is too high, the joint or seal is leaking, the cylinder or motor is severely worn, and the main pump or motor is leaking too much.
  4. The pump is turning incorrectly, the amplifier is malfunctioning, or the amplifier is tuned incorrectly.
  5. Motor failure, overflow valve setting value is low or failure, the pump is blocked or damaged, and the valve fails.

04. Unstable operation of the hydraulic system

When the hydraulic system is unstable, the hydraulic system will slow down or suddenly speed up. In order to prevent this situation from happening, the lubrication conditions should be improved to reduce friction and clean up the stolen goods in time. 

Check whether the oil level is too low and the seal is intact. When the pressure pulse or the system pressure is too low or too large, it is not enough to overcome the external resistance. Check whether the setting value of the overflow valve meets the requirements. If it does not meet the requirements, it should be adjusted in time.

05. The hydraulic system cannot supply oil normally.

  1. During the movement of the hydraulic cylinder, when it is braked or reaches the endpoint, the movement of the hydraulic cylinder has large inertia and momentum, which will cause a greater impact when it is suddenly braked or collided. The pressure increases, and then impacts, which increase the hydraulic impact of the system.
  2. When the direction is changed, the program is turned off or turned on instantly, which causes the potential energy to be converted into kinetic energy, and when the kinetic energy is converted into potential energy, an impact occurs.

Solution:

Check whether the oil level of the fuel tank is too low and whether there is a leak. If a leak is found, add the oil to the normal position. Check whether the suction pipe and the oil filter are blocked. If the viscosity of the oil is too high, the oil tank can be drained and replaced with a lower viscosity oil. If a one-way pump is used in the hydraulic system, there may be a problem with the steering of the pump. At this time, you can correct the wiring and then change the direction.

06. Leakage of hydraulic system

Leakage of the hydraulic systems is one of the common faults of hydraulic systems. The surface geometric accuracy of the valve should be checked in time, whether the concentricity of the valve is sufficient. If the casting parts have pores or cracks, the parts should be replaced, such as aging or The seal is not tight and the seal should be replaced. Check whether the oil pipe joints are loose. If they are loose, they should be tightened in time, and attention should be paid to check whether they are broken.

07. Small system traction

When the hydraulic system has a small traction failure, it is generally necessary to re-check the safety valve of the system and make timely adjustments to the incorrect places; check whether the fuel tank is leaking, repair it and fill it up in time. In addition, the cooling water volume and water pressure need to be adjusted to reach the rated value.

08. The working structure is unstable.

The working structure of the hydraulic system is a relatively complicated process. Therefore, when it is unstable, it should be inspected and repaired in time to avoid unnecessary losses. The main manifestations when the working structure of the hydraulic system is unstable are sudden acceleration or gradual slowing down, abnormal beating, and other phenomena.

  1. The lubrication effect is not good and the resistance is increased. When this situation occurs, the lubricant should be added in time to remove debris to ensure the normal operation of the work.
  2. During work, the oil pump sucks oil, and the air enters the working system. It is necessary to check the oil level and tightness in time to ensure that the oil level reaches the standard level.
  3. The system has no pressure and can not restrain the resistance.

09. Other common faults

  1. If the motor shaft does not rotate when the circuit or power supply is not connected, if the component fails, the motor will turn incorrectly, which will cause the pump to reverse; the
  2. The internal assembly quality of the hydraulic pump is not good, and it is easy to cause a plunger The head is stuck, and the oil temperature is too high to cause some parts to overheat and deform;
  3. When the oil level of the fuel tank is too low, the pump will not suck oil;
  4. At the oil passage, there is a blockage and the oil is dirty;
  5. Due to the inside of the pump, The sliding parts are severely worn and the amount of oil pumped out is obviously insufficient.

The construction principle of liquid equipment is different from other equipment, and it is relatively more complicated, so the diagnosis and treatment of its faults are difficult. When dealing with the problem, we must first systematically understand the failure phenomenon, list the possible causes, and try to solve the problem as soon as possible, and resume production according to the principle of easy first and difficult.