Ph.D. Natalia Petrovskaya: Top 10 posts in February

1. CINEMA and MINING  (1 in the overall ranking)

2. MINING MONEYBALL  (3 in the overall ranking)

3. IN SITU LEACHING IS A MIRACLE OR A NEW ADVERTISING MOVE?  (7 in the overall ranking)

4. SELECTION OF METHODS FOR SEPARATING OF RARE EARTH MINERALS


5. SELECTION OF METHODS FOR SEPARATING OF DIAMOND

6. SELECTION OF METHODS FOR SEPARATING OF GOLD

7. COMMINUTION MODELING

8. SELECTION OF METHODS FOR SEPARATING OF SILICATES


9. Ph.D. Natalia Petrovskaya: Top 10 posts in January


10. SELECTION OF METHODS FOR SEPARATING OF TITANIUM MINERALS


Ph.D. Natalia Petrovskaya

SELECTION OF METHODS FOR SEPARATING OF TITANIUM MINERALS

During the processing of minerals containing titanium, plants use the following types of separation:

• Gravity separation
• Magnetic separation
• Electrical separation

Other methods of separation:

• Flotation

There are three main sources of mineral raw materials for the extraction of titanium:

1. Placer deposits ofores containing titanium (alluvial deposits)
2. Indigenous ore vein deposits containing titanium
3. Waste and not the traditional raw materials containing titanium

The titanium occur in over 255 minerals:

• SILICATES: 163
• OXIDES: 79 (85?)
• ELEMENTS: 5
• PHOSPHATES:  4
• BORATES: 2
• СARBONATES: 1
• Sulfides and Sulfosalts:1
• Sulfate: 1
  

Ph.D. Natalia Petrovskaya



SELECTION OF METHODS FOR SEPARATING OF SILICATES

During the processing of minerals containing silicates, plants use the following types of separation:

• Flotation
• Magnetic separation
• Electrical separation
• Chemical separation
• Gravity separation
• Special methods of separation

 Ph.D. Natalia Petrovskaya

 

MINING MONEYBALL

Small investments can guarantee big profits

I liked the film "Moneyball". The baseball club was in a difficult situation, the best players left, and the club's funding is 2.5-5 times less than that of other clubs. How to achieve victory?

Analytical calculation versus the collective wisdom

In the film "Moneyball" there is an episode when the scouts and the manager choose new players for the club. Look at the criteria they operate on. Like - not like, good - bad, there is a recommendation - there is no. Scouts are clearly subjective. They try to use their wisdom and intuition.
The manager of the club contrasted the accurate analytical calculation to the collective wisdom. He developed a new strategy for selecting players based on a mathematical modeling. As a result, his team went into the playoffs at a cost of 5 times lower than that of other clubs.

The mathematical analysis have their own special beauty, but it is not open to everyone

Our "philosophy of beneficiation" is based on rigorous mathematical analysis plus our knowledge and experience.

We count all the steps before spending money. The result is guaranteed.

If your mining team is at a similar situation, then we can help you get into the playoffs of the world league at low cost. No guesswork - only a rigorous science!

You must be ready to give up stereotypes to win.

12 February 2018
©  Ph.D. Igor Bobin, Ph.D. Natalia Petrovskaya

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SELECTION OF METHODS FOR SEPARATING OF GOLD

Class: Non-Ferrous Metals
Group: Noble metalsMetal: Gold
Chemical formula: AuIngredients: 57-99 % AuMohs scale hardness: 2,5-3Specific gravity: 15,6-19,2 g/cm³
Magnetic properties: Nonmagnetic
During the processing of minerals containing gold, plants use the following types of separation:

• Gravity separation
• Flotation separation
• Chemical separation
• Special methods of separation  and Magnetic separation (the separation of gold from chips)
• Amalgamation

Promising methods for the extraction of golden ore:

• Magnetic separation
• Electrical separation
• Special methods of separation
• Segregation-diffusion concentration

Following methods of ore conditioning are used in processing of golden ore:

• Oxidizing roasting
• Bacterial oxidation (Acidithiobacillus ferrooxidans, Sulfobacillus)
• Autoclave oxidation

There are three main sources of mineral raw materials for the extraction of gold:

1. Placer deposits of ores containing gold (alluvial deposits)
2. Indigenous ore vein deposits containing gold
3. Waste and not the traditional raw materials containing gold

In nature, there are more than 20 mineral forms of gold. It is difficult to choose a method for separating of gold. Minerallurgy can significantly reduce the cost of reagents for hydrometallurgy and reduce the volume of leached ore. For some types of ores the minerallurgy is the sole method of separation of gold in front of pyrometallurgy.Traditional methods of extraction of gold:
Gravity separation. Gravity separation is used to allocate fairly large particles of gold of placer deposits. Gravity separation is used prior to flotation to separate golden particles greater than 0.1 (0.15) mm too. The lower limit size of the use of gravity separation to date is 5 microns. Major losses in golden gravity separation comprise splices of gold with other minerals, platelet-shaped particles of gold, micro and nanoparticles of gold.  Recovery of gold of size of 50-100 microns is 96 %.
Flotation separation. Flotation is the most common and effective way of golden separation, because you can extract the free gold and splices of gold. Floatability of gold depends on the nature of gold, size of fine particles of gold, shape of gold particles, chemical purity of gold, presence of impurities, composition of the films on the surface of golden particles, material composition of the ore. When froth flotation can be extracted particles with a size 150-10 microns. For golden particles less than 20 microns is best to use special methods of flotation. In addition, the golden particles of different size of one field have different flotation properties.
Chemical enrichment (chemical separation, hydrometallurgy). Heap leaching of ore or concentrate is used mainly with cyanide (recovery of gold is around 60-90 %). Situ leaching is used with chlorine too (extraction of gold may reach 75 %). Also there are pressure leaching and bacterial leaching. Chemical processing is not used for macrogold and colloidal gold. Leaching uses the following types of solvents: cyanides, hypochlorite and other solutions (thiourea). To separate the gold from solution can be used metal deposition, electrolysis, adsorption with activated carbon, sorption of synthetic ion-exchange resins.
Composition of the golden ore often contains the following minerals: quartz, pyrite, arsenopyrite, gray ores, sphalerite, galena, chalcopyrite, magnetite, barite, tourmaline, carbonates, bismuthine.
Composition of natural gold includes the following admixtures: silver, copper, lead, bismuth, antimony, iron, tellurium, and arsenic. Impurity complicates the selection process of method for  gold separation and development of technology to extract gold.
Impurity reduces the value of gold and changes its properties:

• Impurity reduces the density of gold.
• Impurity alters the structure of gold.
• Impurity alters the color of gold (from pale yellow to reddish or greenish).
• Impurity of iron gives the magnetic properties of gold.

Gold is classified by the following features:

By mineral form:

• Native gold (it can be extracted by gravity separation, chemical separation)
• Sulphides (gold can be extracted by flotation separation, chemical separation)
• Galloidy (gold can be extracted by chemical separation)
• Carbonaceous ore and other forms.

By connection with other minerals:

• Free gold (it can be extracted by gravity separation, flotation, chemical separation)
• Splice of gold (gold can be extracted by flotation, chemical separation)
• Gold that enclosed in a mineral or inside the crystal lattice (gold can be extracted by flotation, pyrometallurgy)

By size of particles:

• Macrogold is very large (greater than 0.5 mm). It can be extracted by gravity concentration.
• Coarse gold (fat gold) is in a free state (70 micron). It is easily releases during grinding. It can be extracted by gravity concentration. Coarse gold floats badly. For large-scale leaching of gold requires a lot of time.
• Fine gold is partly in a free state and partly in the splice (70-1 micron). Free fine gold floats well and quickly dissolves in the leaching. Using of gravity separation is possible, but it difficult. Fine gold with splice recoveries by flotation too. Fine gold in intergrowths with sulfides floats well, fine golden splice with nesulfidami floats much worse. Fine golden splice is well dissolved in the leaching.
• Microgold is finely divided (less than 1 micron). When grinding ore microgold opens slightly, the bulk of gold remains in the mineral. Most often, these minerals are pyrite and arsenopyrite. The content of gold in pyrite may be several grams per ton. For the separation of golden splices used flotation and chemical separation. Splices of gold with iron hydroxides, carbonates are leached well even with rough grinding. Splices of gold with sulphides after flotation is subjected to oxidizing roasting of sulfides to decompose, and then are leached (or immediately directed to the pyrometallurgy). Splices of gold with quartz after flotation are sent to pyrometallurgy.
• Nanogold is disseminated nanoparticles of gold on minerals. Nanogold as fine disseminations may be present in the following sulfides: pyrite, arsenopyrite, pyrrhotite, chalcopyrite, galena, sphalerite, covellite, bismuthine. Nanogold presents in the auriferous quartz in the form of nano disseminations. Also nanogold cans be inside the crystal lattices of other minerals. Only special methods can be used to extract nanogold.
• Colloidal gold is an unstable form of gold. The size of colloidal gold particles is not strictly set. The developed technology of separation of colloidal gold doesn’t exist now.

Today only macrogold, coarse and fine gold are extracted on a commercial scale.
The main reasons for the partial extraction of gold are "suspicious" gold and "coating" of other minerals on the surface of gold.
The shape of the gold particles affects to the choice of method for gold separation. Gravity separation is better to recover gold particles of isometric shape. Flotation better to recover gold particles that have the shape of flakes and plates (floating gold).
The surface "coating" on the gold particles interferes to flotation and leaching, but it doesn’t have much effect on gravity separation.

© Ph.D. Natalia Petrovskaya,

01 December, 2015

nataliapetrovsky@gmail.com

SELECTION OF METHODS FOR SEPARATING OF RARE EARTH MINERALS

During the processing of minerals containing rare earth mineral, plants use the following types of separation:

• Gravity separation
• Magnetic separation
• Electrical separation
• Chemical separation
• Flotation
• Special methods of separation

 
 Ph.D. Natalia Petrovskaya

SELECTION OF METHODS FOR SEPARATING OF DIAMOND

During the processing of minerals containing diamond, plants use the following types of separation:

• Gravity separation
• Flotation
• Special methods of separation 
• Pretreatment

© Ph.D. Natalia Petrovskaya

nataliapetrovsky@gmail.com

IN SITU LEACHING IS A MIRACLE OR A NEW ADVERTISING MOVE?

Currently, I often meet many projects where they offer In situ leaching of ores (In situ leaching, In-situ leaching (ISL), in-situ recovery (ISR), solution mining).

In situ leaching (ISL) is a miracle or a new advertising move? Let's find out!

Today they use ISL for ores containing:

• Uranium
• Gold
• Copper

They suggest using ISL for ores containing:

• Hafnium
• Zirconium
• Scandium
• Vanadium
• Titanium
• Lithium
• Nickel
• Zinc
• Lead
• Tin
• Chromium
• Phosphates
• Potash
• Borates

The use of In situ leaching (ISL) has significant limitations!

The effectiveness of underground leaching depends on:

• The permeability of the ore body and enclosing rocks (filterability). Permeability of the ore body must to exceed the permeability of the host rocks. Rocks, limiting ore body must be impermeable to the working solution. Reacting of working solution with the ore body should not resist to filtration of the working solution).
• The chemical and mineral composition of the ore and host rocks. (It should be ensured maximum extraction under economically acceptable reagent consumption. Useful components should not be in the form of isomorphic impurities).
• The structure and texture of ores (This method is used in permeable sandy deposits of loose and well penetrated ores).
• The size and shape of the ore body (Applies for deposits of reservoir type).
• The depth of the ore body (Used for fields located in the upper horizons (shallow ores). The occurrence of the ore body at a depth of 1000 ft and more is considered to be unfavorable conditions).
• The content of carbonate rocks (grade of more than 2% of carbonates is considered unfavorable condition)
• The filtration uniformity of minerals
• The discharge of reservoir waters, their chemical composition

When leaching, you get a solution containing many chemical elements. The separation of these elements can be very expensive.

Manufacturers of reagents do not have a wide assortment of reagents!

The prices are high. Leaching requires a large consumption of the leaching reagents. Therefore the leaching is considerably more expensive than traditional methods of ore processing (ore enrichment). Pumps are also very expensive. So illusions of cheapness and simplicity of In situ leaching (ISL) disappear in most cases of its actual application. When using the underground leaching method, you can make changes only at the design stage. In this case, change the method of separation or technology at the finished plant cannot be made.
I am always very cautious about such projects. Very few deposits can be processed using In situ leaching (ISL).

Sometimes this is a way to sell you a poor deposit under the guise of a new trend!

You can contact our website for more information
Contact us directly. Don’t buy anything without our independent assessment - this is too risky. Don't succumb to cheap promises and simple solutions. Anything of these doesn't exist. Each step can lead you to great loss. Remember that! We will share with you the knowledge that any expert doesn't have in the world! We know everything in the mineral enrichment. We have no competitors. Only we can theoretically calculate and simulate FOR YOU the UNIQUE TECHNOLOGY, which anybody doesn't have in the world.
Hurry, because our small team may be busy again on another project, and you will have to wait.
Give yourself a chance to become rich and to earn billions!

© Ph.D. Natalia Petrovskaya, Ph.D. Igor Bobin

nataliapetrovsky@gmail.com

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COMMINUTION MODELING

 You can download articles about 
COMMINUTION MODELING in PDF for free,  
on the website "MINERAL MODELING".  
 
 Author is Ph.D. Igor Bobin.

COMMINUTION KINETICS AND VELOCITY. Second order with delay

By Ph.D. Igor Bobin, February 12, 2017

More...

UNIVERSAL EQUATION OF COMMINUTION KINETICS

By Ph.D. Igor Bobin, January 25, 2017

More...

UNIVERSAL EQUATION OF GRINDING KINETICS

By Ph.D. Igor Bobin, Ph.D. Natalia Petrovskaya, January 23, 2017

Today unconventional types of ores are involved in the processing in large quantities. The main trend now is to obtain ultra fine grinding of ores. This has led to the fact that crushing and grinding operations are the most costly at the plant. Costs for grinding can reach 60% of the total cost of ore processing.

Now we can’t say that there is enough knowledge about the problem of the development and the use of mathematical models in relation to the grinding and crushing processes. Currently, there are no universal models for crushing and grinding processes. Throughout the world there is an objective need for the development of mathematical models of crushing and grinding. More...

CURVES OF COMMINUTION KINETICS (grinding, crushing)

By Ph.D. Igor Bobin, January 22, 2017

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FORMULA FOR THE DIRECT CALCULATION OF THE COMMINUTION  Velocity

By  Ph.D. Igor Bobin, December 27, 2016

In previous articles [1-3] we have talked about the modeling of comminution kinetics (crushing and grinding kinetics) C = f (t), where C – is the content of the size fraction (size class) of final product, %;  t – is time, secs.
Now we are acquainting with сomminution velocity v_c.

Comminution velocity (rate) v_c is ratio of the size fraction content C to unit of time t. Comminution velocity is derivative of time  v_c = dC/dt  (%/secs).

Our modeling approach to comminution kinetics allows to carry direct calculation of сomminution velocity, pioneering move. A visual representation of the сomminution velocity in time is very important for solving the optimization problem of the mineral processing technology.  More...

EQUATION OF COMMINUTION KINETICS WITH DELAY

By Ph.D. Igor Bobin, Ph.D. Natalia Petrovskaya,  December 18, 2016

Rock is a variety of different minerals united together. A comminution process is used to liberate one mineral from another. The size of the pieces of rock decreases with the comminution and mineral particles are released.

The purpose of the comminution is to obtain the finished product of a certain size. The finished product is directed to the separation of one mineral from another.

Crushing and grinding operations are expensive, so the kinetics of grinding (сrushing, comminution) is very important for the management.

The comminution kinetics reflects the change of the content of the size fraction (size class) of finished product in time: C = f(t).      More....

© Ph.D. Igor Bobin

bobin.igor@yahoo.com